CN1293701C - Step failing out detecting apparatus and method for synchronous motor, driving apparatus for motor - Google Patents

Abstract

The present invention provides a synchronous motor out-of-synchronization detection device that can detect synchronous motor out-of-synchronization with high accuracy through a simplified out-of-synchronization detection process. In a commutation device that drives a synchronous motor without using a position sensor for detecting the rotor position, It is characterized in that it has a current detection device that detects the current flowing in the synchronous motor; and transforms the coordinates of the current signal obtained from the current detection device into a dq coordinate transformation of an excitation current component (d-axis current) and a torque current component (q-axis current) device; seek the current alternating component detection device of the alternating component of the dq axis current obtained from the dq coordinate transformation device; at least one of the above-mentioned dq axis current alternating components obtained from the current alternating component detection device and the arbitrarily set out-of-step electric current Out-of-synchronization detection means for detecting out-of-synchronization by comparing a flat signal.

Description

Synchronous motor out-of-step detection device and out-of-step detection method, motor drive device

technical field

The present invention relates to a synchronous motor out-of-synchronization detection device and a synchronous motor out-of-synchronization detection method for driving a synchronous motor without using a position sensor for detecting a rotor position.

Background technique

FIG. 9 shows the structure of a general conventional inverter. In the figure, 1 is a DC power supply unit, 2 is an inverter device, 3 is a plurality of switching elements, 3a is a U-phase upper switching element, 3b is a V-phase upper switching element, 3c is a W-phase upper switching element, 3d 3 is a U-phase lower switching element, 3e is a V-phase lower switching element, and 3f is a W-phase lower switching element. 4 is a plurality of freewheeling diodes connected in parallel with a plurality of switching elements 3 , 5 is an inverter main circuit composed of a plurality of switching elements 3 and a plurality of freewheeling diodes 4 , and 6 is a DC brushless motor.

7a is a current detection device that detects one-phase current of the current flowing into the DC brushless motor 6, 7b is a current detection device that detects a current that is out of phase with the current detection device 7a, and 8 is a current detection device based on the current detection device 7a, 7b. The detected current value is an inverter control device that controls switching elements 3 in the inverter main circuit 5 on and off.

9 is a PWM signal generating device for generating a PWM signal for on-off control of the switching element 3 based on the output voltage command value obtained in the inverter control device 8, and 10 is the output voltage detected by the current detecting devices 7a and 7b. The current value of the phase part asks the phase current operation device of the three-phase current value, 11 is the 3-phase 2-phase conversion device that converts the three-phase current value obtained by the phase current operation device into the current value of the d-q coordinate system, and 12 is based on The current value of the d-q coordinate system obtained by the 3-phase 2-phase conversion device 11 is used to obtain the voltage command value calculation device for the output voltage command value of the d-q coordinate system used to drive the DC brushless motor, and 13 is based on the voltage command value calculation device. 12 is an output voltage vector calculation device for obtaining an output voltage vector from the output voltage command value of the d-q coordinate system obtained, 14 is a DC voltage detection device for detecting the DC voltage of the DC power supply 1, and 70 is an overcurrent for detecting the overcurrent state of the phase current detection device.

Operations in the commutation device and DC brushless motor configured as described above will be described with reference to FIG. 9 . In the figure, the inverter device 2 detects the currents of two phases of the phase currents flowing into the DC brushless motor 6 by the current detection devices 7a and 7b. Using the detected currents of the two phases, such as the U-phase current Iu and the V-phase current Iv, the commutation control device 8 calculates the voltage value and voltage output by the converter main circuit 5 in order to drive the DC brushless motor 6 The output voltage command value of the phase is output as a PWM signal for on/off control of the switching element 3 in the inverter main circuit 5 .

In the commutation control device 8, a PWM signal is output by the operation described below. According to the phase current Iu, Iv detected by the current detection device 7a, 7b, the phase current Iu, Iv, Iw of the three-phase part is calculated in the phase current calculation device 10, and the phase current Iu, Iv, Iw of the three-phase part is obtained by the three-phase two-phase conversion device. The currents Iu, Iv, and Iw are transformed into currents Id, Iq in the d-q coordinate system. The voltage command value calculation device 12 calculates the output voltage command values Vd* and Vq* in the d-q coordinate system from the current Id and Iq of the d-q coordinate system, and the output voltage vector calculation device 13 obtains the output voltage command value Vd* from the d-q coordinate system. , Vq* Calculate the output voltage vector Vx* through calculation. PWM signal generator 9 obtains and outputs a PWM signal for on-off control of switching element 3 from DC voltage Vdc obtained by DC voltage detector 14 and output voltage vector Vx*.

According to the PWM signal output by the PWM signal generator 9, the switching element 3 in the inverter main circuit 5 is turned on and off. According to the ON/OFF operation of the switching element 3, electric power is supplied from the inverter main circuit 5 to the DC brushless motor 6, and the DC brushless motor is driven.

Here, the out-of-synchronization detection in the conventional commutation device described above is performed as follows. When the DC brushless motor 6 is out of step, since the peak level of the phase current becomes larger than that during synchronous operation, the out of step is detected from this phenomenon. For example, the phase current value is compared with the overcurrent level by the overcurrent detection device 70, and when the phase current exceeds the overcurrent level, it is regarded as an overcurrent abnormality, and out-of-synchronization detection is performed based on the overcurrent abnormality. Here, the overcurrent detection device 70 is constituted by hardware or software.

In addition, JP-A-11-18499 discloses another example of a conventional out-of-synchronization detection device for a synchronous motor. In the out-of-step detection device of a synchronous motor disclosed in JP-A-11-18499, it is described that in the controller, a γ-δ axis set so as to rotate at an estimated speed ωr is formed on the rotor, and the sum of the γ-δ axes on the rotor is obtained. The error θe of the d-q axis. An example of synchronous motor out-of-synchronization detection by sequentially comparing two estimated values by configuring a state estimator for estimating the γ-axis induced voltage and δ-axis induced voltage as a function of θe occurring in the γ-δ axis.

Furthermore, JP-A-2001-25282 discloses another example of a conventional out-of-synchronization detection device for a synchronous motor. In JP-A-2001-25282, a synchronous motor out-of-synchronization detection device is disclosed, which compares the period of the voltage output by the commutation device with the period of the current flowing in the sensorless brushless motor to detect out-of-synchronization example of. Also disclosed is an example in which out-of-synchronization is detected by comparing the d-axis current, which is an exciting current component, with an out-of-synchronization detection level.

The conventional out-of-synchronization detection device for a synchronous motor is configured as above, and since the out-of-synchronization state is detected from an overcurrent phenomenon, it is difficult to detect out-of-synchronization with high accuracy. In addition, even if synchronous operation continues without out-of-synchronization, it is difficult to separate the out-of-synchronization phenomenon from the overcurrent phenomenon when an overcurrent occurs due to an increase in load or over-deceleration of the speed. In addition, the overcurrent level used in the overcurrent detection device is set according to the demagnetization yield point of the magnet used in the rotor of the DC brushless motor or the level of the critical current of the element used in the inverter device value, it is therefore difficult to independently set the detection level used in out-of-sync detection.

In addition, depending on the combination of the inverter device and the DC brushless motor, the current at the time of out-of-synchronization may be smaller than the current at the synchronous state, so detection by overcurrent may not be possible.

When the out-of-step state continues as described above, there is a problem that vibration or noise of the motor rotor occurs. In addition, the device may malfunction due to the vibration of the motor. In addition, there is a problem that the current flowing through the synchronous motor increases, causing damage to semiconductor elements and the like used in the inverter device.

In addition, in the synchronous motor out-of-synchronization detection device disclosed in JP-A-11-18499, since a device for estimating the induced voltage of the electrodes is required for out-of-synchronization detection, the arithmetic processing load of the microcomputer and the like increases.

In addition, in the synchronous motor out-of-synchronization detection device disclosed in JP-A-2001-25282, since the out-of-synchronization is detected by comparing the voltage cycle output by the commutation device with the current cycle flowing in the sensorless brushless motor, Therefore, in a state where there is no difference between the cycle of the voltage output by the inverter device and the cycle of the current flowing through the synchronous motor at the time of a step-out, the step-out detection cannot be performed. In addition, in a device that detects out-of-synchronization by comparing the d-axis current that is an excitation current component with the out-of-synchronization detection level, since the excitation current changes depending on the number of revolutions or the conditions of the load torque, it is necessary to set the out-of-synchronization for each operating condition. step detection level, making the setting complicated.

Contents of the invention

The present invention was made to solve the above problems, and an object of the present invention is to provide a synchronous motor out-of-synchronization detection device and a synchronous motor out-of-synchronization detection method capable of detecting out-of-synchronization of a synchronous motor with high accuracy through a simple out-of-synchronization detection process.

Another object is to provide a drive device for a hermetic compressor and a drive device for a fan motor in which the out-of-synchronization detection device for a synchronous motor as described above is mounted.

The synchronous motor out-of-step detection device of the present invention is characterized in that it is equipped with a current detection device that detects the current flowing in the synchronous motor; The coordinate transformation of the current signal obtained by the detection device is a d-q coordinate conversion device for the excitation current component (d-axis current) and the torque current component (q-axis current); the current exchange of the d-q axis current AC component obtained from the d-q coordinate conversion device Component detecting means; an out-of-synchronization detecting means for detecting out-of-synchronization by comparing at least one of the aforementioned d-q axis current alternating components obtained from the current alternating-current component detecting means with an arbitrarily set out-of-synchronization level signal.

In addition, the synchronous motor out-of-step detection device of the present invention is characterized in that it includes a current detection device for detecting the current flowing in the synchronous motor in a commutation device that drives a synchronous motor without using a position sensor for detecting the rotor position; The coordinate transformation of the current signal obtained from the current detection device into the d-q coordinate conversion device for the exciting current component (d-axis current) and the torque current component (q-axis current); the AC component of the d-q axis current obtained from the d-q coordinate conversion device Current AC component detection device; the average value of the effective value or absolute value of the d-q axis current AC component obtained from the current AC component detection device, and the AC component averaging device for averaging the d-q axis current AC component; the AC component averaging device Out-of-synchronization detection means for detecting out-of-synchronization by comparing at least one of the average values of the obtained d-q axis current AC components with an arbitrarily set out-of-synchronization level signal.

In addition, the synchronous motor out-of-step detection device of the present invention is characterized in that it includes a current detection device for detecting the current flowing in the synchronous motor in a commutation device that drives a synchronous motor without using a position sensor for detecting the rotor position; The coordinate transformation of the current signal obtained from the current detection device is a d-q coordinate conversion device for the excitation current component (d-axis current) and the torque current component (q-axis current); find the d-q coordinate current and d-q coordinate current obtained from the d-q coordinate conversion device A current error computing device for the error of the command value; a current error AC component detecting device for detecting the AC component of the d-q axis current error obtained from the current error computing device; Out-of-synchronization detection means for detecting out-of-synchronization by comparing at least one of them with an arbitrarily set out-of-synchronization level signal.

In addition, the out-of-synchronization detecting device of the synchronous motor according to the present invention is characterized in that only a specific frequency component is detected when an AC component is detected from a d-q coordinate system current.

In addition, the synchronous motor out-of-synchronization detecting device of the present invention is characterized in that a specific frequency component is set to double the frequency of the voltage output from the inverter device.

In addition, the out-of-synchronization detecting device of the synchronous motor according to the present invention is characterized in that only a specific frequency component is detected when detecting the AC component of the d-q axis current error.

In addition, the out-of-synchronization detecting device of the synchronous motor of the present invention is characterized in that the out-of-synchronization detection level compared with the average value of the q-axis current AC component is set to be about 200% of the rated current of the synchronous motor.

In addition, the out-of-synchronization detecting device of the synchronous motor of the present invention is characterized in that when it is difficult to detect out-of-synchronization at low speed, it accelerates to a constant operating speed immediately after starting to detect out-of-synchronization.

In addition, the out-of-synchronization detecting device of the synchronous motor according to the present invention is characterized in that the out-of-synchronization detection process is performed outside the process of acceleration and deceleration when an erroneous detection of out-of-synchronization may occur during acceleration and deceleration of the synchronous motor.

In addition, the synchronous motor out-of-synchronization detection device of the present invention is characterized in that a current detection device for detecting a current flowing in the synchronous motor is provided in a commutation device that drives a synchronous motor without using a position sensor for detecting a rotor position; according to The output voltage command value calculation device for calculating the output voltage command value added to the synchronous motor from the current signal obtained from the current detection device; the output voltage vector calculation device for calculating the output voltage vector based on the output voltage command value obtained from the output voltage command calculation device ; The output voltage abnormality detection device comparing the magnitude of the output voltage vector obtained from the output voltage vector calculation device with the out-of-synchronization detection level; The out-of-synchronization detection device detecting out-of-synchronization according to the comparison result obtained from the output voltage abnormality detection device.

In addition, the out-of-step detection method of a synchronous motor according to the present invention, in a commutation device that drives a synchronous motor without using a position sensor for detecting a rotor position, is characterized in that a current detection step of detecting a current flowing in a synchronous motor is provided; The coordinate transformation of the current signal obtained from the current detection step is the d-q coordinate transformation step of the exciting current component (d-axis current) and the torque current component (q-axis current); the AC component of the d-q axis current obtained from the d-q coordinate transformation step Current AC component detection step: Out-of-synchronization detection step of comparing at least one of the d-q axis current AC components obtained from the current AC component detection step with an arbitrarily set out-of-synchronization level signal.

In addition, the out-of-step detection method of a synchronous motor according to the present invention, in a commutation device that drives a synchronous motor without using a position sensor for detecting a rotor position, is characterized in that a current detection step of detecting a current flowing in a synchronous motor is provided; The coordinate transformation of the current signal obtained from the current detection step is the d-q coordinate transformation step of the exciting current component (d-axis current) and the torque current component (q-axis current); the AC component of the d-q axis current obtained from the d-q coordinate transformation step The current AC component detection step; the average value of the effective value or absolute value of the d-q axis current AC component obtained from the current AC component detection step, and the AC component averaging step of averaging the d-q axis current AC component; the AC component average step An out-of-synchronization detection step of comparing at least one of the obtained average values of the d-q axis current AC components with an arbitrarily set out-of-synchronization level signal to detect out-of-synchronization.

In addition, the out-of-step detection method of a synchronous motor according to the present invention, in a commutation device that drives a synchronous motor without using a position sensor for detecting a rotor position, is characterized in that a current detection step of detecting a current flowing in a synchronous motor is provided; The coordinate transformation of the current signal obtained from the current detection step is the d-q coordinate transformation step of the excitation current component (d-axis current) and the torque current component (q-axis current); find the d-q coordinate current and the d-q coordinate current obtained from the d-q coordinate transformation step A current error operation step of an error of a command value; a current error AC component detection step of detecting an AC component of a d-q axis current error obtained from the current error operation step; a step of detecting an AC component of a d-q axis current error obtained from a current error AC component detection step An out-of-synchronization detection step of detecting out-of-synchronization by comparing at least one side with an arbitrarily set out-of-synchronization level signal.

In addition, the out-of-synchronization detection method of a synchronous motor according to the present invention is characterized in that only a specific frequency component is detected when an AC component is detected from a d-q coordinate system current.

In addition, the out-of-synchronization detection method of the synchronous motor of the present invention is characterized in that a specific frequency component is set to twice the frequency of the voltage output from the inverter device.

In addition, the out-of-synchronization detection method of a synchronous motor according to the present invention is characterized in that only a specific frequency component is detected when detecting an AC component of a d-q axis current error.

In addition, the out-of-synchronization detection method of the synchronous motor of the present invention is characterized in that the out-of-synchronization detection level compared with the average value of the q-axis current AC component is set to about 200% of the rated current of the synchronous motor.

In addition, the out-of-synchronization detection method of the synchronous motor of the present invention is characterized in that when the out-of-step detection is difficult at low speed, the out-of-synchronization is detected by accelerating to a constant operating speed immediately after starting.

In addition, the out-of-synchronization detection method of a synchronous motor according to the present invention is characterized in that the out-of-synchronization detection process is performed outside the process of acceleration and deceleration when an erroneous detection of out-of-synchronization may occur during acceleration and deceleration of the synchronous motor.

In addition, the out-of-synchronization detection method of a synchronous motor according to the present invention, in a commutation device that drives a synchronous motor without using a position sensor for detecting a rotor position, is characterized in that a current detection step of detecting a current flowing in a synchronous motor is provided; according to The output voltage command value calculation step of calculating the output voltage command value added to the synchronous motor from the current signal obtained in the current detection step; the output voltage vector calculation step of calculating the output voltage vector according to the output voltage command value obtained from the output voltage command calculation step ; An output voltage abnormal detection step of comparing the magnitude of the output voltage vector obtained from the output voltage vector calculation step with the out-of-synchronization detection level; an out-of-synchronization detection step of detecting out-of-synchronization according to the comparison result obtained from the output voltage anomaly detection step.

The driving device of the hermetic compressor of the present invention is characterized by being equipped with the out-of-synchronization detection device of the synchronous motor of the present invention.

The driving device of the fan motor of the present invention is characterized by being equipped with the out-of-synchronization detection device of the synchronous motor of the present invention.

Description of drawings:

Fig. 1 shows the configuration of a synchronous motor out-of-synchronization detection device according to the first embodiment.

Fig. 2 illustrates various waveforms during synchronous operation in the first embodiment.

Fig. 3 illustrates various waveforms at the time of out-of-synchronization in the first embodiment.

Fig. 4 is a flowchart showing the flow of out-of-synchronization detection processing in the first embodiment.

Fig. 5 illustrates various waveforms at the time of out-of-synchronization in the first embodiment.

Fig. 6 is a flowchart showing the flow of out-of-synchronization detection processing in the first embodiment.

Fig. 7 shows the configuration of a synchronous motor out-of-synchronization detection device according to Embodiment 2.

Fig. 8 is a flowchart showing the flow of out-of-synchronization detection processing in the second embodiment.

FIG. 9 shows the configuration of a conventional out-of-synchronization detection device for a synchronous motor.

Specific Embodiments of the Invention

Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1

Figures 1 to 6 show Embodiment 1, Figure 1 shows the structure of the converter device, Figure 2 illustrates various waveforms during synchronous operation, Figure 3 illustrates various waveforms during out-of-synchronization, and Figure 4 illustrates the out-of-synchronization detection process Flowchart, Figure 5 illustrates various waveforms when out of sync, and Figure 6 is the flow of out of sync detection processing.

In Fig. 1, 1 is a DC power supply unit, 2 is an inverter device, 3 is a plurality of switching elements, 3a is a U-phase upper switching element, 3b is a V-phase upper switching element, 3c is a W-phase upper switching element, 3d is a U-phase lower switching element, 3e is a V-phase lower switching element, and 3f is a W-phase lower switching element. 4 is a plurality of freewheeling diodes connected in parallel with a plurality of switching elements 3 , 5 is an inverter main circuit composed of a plurality of switching elements 3 and a plurality of freewheeling diodes 4 , and 6 is a DC brushless motor.

7a is a current detection device that detects one phase current of the current flowing into the DC brushless motor 6, 7b is a current detection device that detects a phase current different from the current detection device 7a, and 8 is a current detection device based on the current detection device 7a, 7b. The detected resistance value is an inverter control device that controls on/off the switching element 3 in the inverter main circuit 5 .

9 is a PWM signal generating device for generating a PWM signal for on/off controlling the switching element 3 based on the output voltage command value obtained in the inverter control device 8, and 10 is the signal detected by the current detecting device 7a, 7b. The current value of the two-phase part calculates the phase current calculation device of the three-phase current value, and 11 is a three-phase d-q coordinate conversion device that converts the three-phase current value obtained by the phase current calculation device 10 into a current value of the d-q coordinate system. The 2-phase conversion device, 12 is a voltage command value calculation device for obtaining the output voltage command value of the d-q coordinate system for driving the DC brushless motor based on the d-q coordinate system current value obtained by the 3-phase 2-phase conversion device 11, 13 is an output voltage vector computing device for obtaining an output voltage vector from the output voltage command value of the d-q coordinate system obtained by the voltage command value computing device 12, and 14 is a DC voltage detecting device for detecting the DC voltage of the DC power supply 1.

15 is to detect the alternating current component detection device of the d-q coordinate system electric current that obtains from 3-phase 2-phase conversion device 11, and 16 is to compare the alternating current component of the d-q coordinate system electric current obtained from alternating current component detection device 15 with the out-of-step level. Compare out-of-synchronization detection devices for out-of-synchronization detection.

The operation of the commutation device configured as above will be described with reference to FIG. 1 . In the figure, the inverter device 2 detects the currents of two phases of the phase currents flowing in the DC brushless motor 6 using the current detection devices 7a and 7b. In order to drive the DC brushless motor 6, the commutation control device 8 uses the detected currents of the two phases, such as the U-phase current Iu and the V-phase current Iv, to calculate the voltage value and the voltage output from the main circuit 5 of the converter. A voltage command value such as a phase is output, and a PWM signal for on/off controlling the switching element 3 in the inverter main circuit 5 is output.

In the commutation control device 8, a PWM signal is output by the operation described below. According to the phase current Iu, Iv detected by the current detection device 7a, 7b, the phase current Iu, Iv, Iw of the three-phase part is obtained in the phase current calculation device 10, and the three-phase part is converted by the 3-phase 2-phase conversion device 11 The phase currents Iu, Iv, and Iw are converted into currents Id, Iq in the d-q coordinate system. The voltage command value calculation device 12 calculates the output voltage command values Vd* and Vq* in the d-q coordinate system from the current Id and Iq of the d-q coordinate system, and the output voltage vector calculation device 13 obtains the output voltage command value Vd* from the d-q coordinate system. , Vq* Calculate the output voltage vector Vx* through calculation. The PWM signal generator 9 obtains and outputs a PWM signal for on/off control of the switching element 3 from the DC voltage Vdc obtained by the DC voltage detector 14 and the output voltage vector Vx*.

According to the PWM signal output by the PWM signal generator 9, the switching element 3 in the inverter main circuit 5 is turned on and off. According to the ON/OFF operation of the switching element 3, electric power is supplied from the inverter main circuit 5 to the DC brushless motor 6, and the DC brushless motor is driven.

From the d-q coordinate system current Id, Iq supplied from the 3-phase 2-phase conversion device 11, the AC component detection device 15 detects the AC component Id_AC, Iq_AC of the d-q coordinate system current Id, Iq. The out-of-synchronization detection device 16 compares the AC components Id_AC and Iq_AC of the d-q coordinate system current with the out-of-synchronization detection level Error_Level, and outputs an abnormal stop signal as out-of-synchronization when Id_AC or Iq_AC exceeds the out-of-synchronization detection level Error_Level.

When the out-of-synchronization detection device 16 outputs an abnormal stop signal, the PWM signal generator 9 outputs a signal for turning off all the switching elements 3 in the inverter main circuit 5, and stops the transmission from the inverter main circuit 5 to the DC inverter. The power supply of the brush motor 6. At the same time, the operation of the commutation control device 8 is also stopped.

Next, details of the out-of-synchronization detection method of this embodiment will be described using FIG. 2 and FIG. 3 . The waveform diagram shown in FIG. 2 shows an example of various waveforms when the brushless motor 6 operates synchronously normally. In Fig. 2, the waveform (a) shows the phase current waveform Iu obtained from the current detection device 7a, the waveform (b) shows the d-axis current waveform Id obtained from the 3-phase 2-phase conversion device, and the waveform (c) shows the phase current waveform Id obtained from the current detection device 7a. The waveform (d) of the q-axis current waveform Iq obtained by the 3-phase 2-phase conversion device 11 shows the AC component waveform Iq_AC of the q-axis current Iq.

The waveforms shown in FIG. 3 show an example of various waveforms when the brushless DC motor is out of step. In Fig. 3, the waveform (a) shows the phase current waveform Iu obtained from the current detection device 7a, the waveform (b) shows the d-axis current waveform Id obtained from the 3-phase 2-phase conversion device, and the waveform (c) shows the phase current waveform Id obtained from the current detection device 7a. The waveform (d) of the q-axis current waveform Iq obtained by the 3-phase 2-phase conversion device 11 shows the AC component waveform Iq_AC of the q-axis current Iq.

As shown in Figure 2 and Figure 3, if the DC brushless motor is in a synchronous operation state, the current Id and Iq in the d-q coordinate system are almost DC, and in the out-of-step state, AC components are generated in Id and Iq. As in the waveform (d) of FIG. 3 , the AC components Id_AC and Iq_AC of Id and Iq are compared with the out-of-synchronization detection level Error_Level, and when the value exceeds this value, it is regarded as out-of-synchronization. Out-of-synchronization detection can be performed by such an operation.

The phenomenon in which AC components are generated in Id and Iq will be described below. In particular, in a motor with different d-axis and q-axis inductances such as IPMSM (implanted magnet synchronous motor), in the synchronous operation state, since the relationship between the rotor phase and the output voltage phase of the inverter maintains a constant phase In the poor state, that is, when the d-axis and q-axis inductances of the rotor are constant based on the output voltage phase of the inverter, the d-axis current Id and q-axis current Iq are almost DC. On the other hand, in the out-of-step state, since the relationship between the rotor phase and the output voltage phase of the converter is always a dynamic state, that is, when the output voltage phase of the converter is used as a reference, the inductance of the d-axis and q-axis Since it is always fluctuating, the d-axis current and the q-axis current fluctuate for every rotation phase, and each generates an AC component. Thus, by detecting the AC component of the d-q axis current, it is possible to capture the fluctuation of the d-axis and q-axis inductance of the rotor (the operating state of the rotor) observed from the output voltage phase of the inverter, thereby enabling detection of synchronous Motor out of step.

An example of the out-of-synchronization detection device according to the first embodiment will be described using FIG. 4 , particularly a device using the q-axis current Iq corresponding to the output torque component of the current flowing into the motor. FIG. 4 is a flowchart showing the flow of out-of-synchronization detection processing. In Figure 4, STP1 is out-of-synchronization detection start processing, STP2 is phase current detection processing, STP3 is phase current calculation processing, STP4 is 3-phase 2-phase conversion processing, STP5 is AC component detection processing, and STP6 is out-of-synchronization level comparison As a result, STP7 is PWM stop processing, STP8 is abnormal end processing, and STP9 is normal end processing.

The process of out-of-synchronization detection is as follows. Based on the out-of-synchronization detection processing started at STP1, currents Iu and Iv flowing into two phases of the DC brushless motor 6 are detected by the current detection devices 7a and 7b in the phase current detection processing of STP2. In the phase current calculation process of STP3, the currents Iu, Iv, and Iw of the three-phase portion are obtained from the currents Iu, Iv of the two-phase portion obtained at STP2. In the three-phase-to-two-phase conversion process of STP4, the currents Iu, Iv, and Iw of the three-phase portion obtained at STP3 are converted into currents Id, Iq of the d-q coordinate system. In the AC component detection process of STP5, the AC component Iq_AC of the q-axis current Iq obtained at STP4 is detected by a high-pass filter.

In the out-of-synchronization level comparison process of STP6, the q-axis current AC component Iq_AC obtained at STP5 is compared with the out-of-synchronization level Error_Level, and when Iq_AC≥Error_Level is regarded as out-of-synchronization, the process proceeds to STP7. When Iq_AC<Error_Level, it is deemed that synchronous operation is in progress, and the process proceeds to STP9. In the PWM stop processing of STP7, when it is judged to be out-of-synchronization at STP6, all the PWM signals output by the PWM signal generator 9 are set to a stop state, and then the operation of the commutation control device is stopped. In the abnormal end processing of STP8, the out-of-synchronization detection is abnormally ended as out-of-synchronization. In the normal end processing of STP9, the out-of-synchronization detection processing is terminated as normal operation.

As above, by detecting the change of the d-q axis current during normal operation and when the step is out, it is possible to detect the out-of-step of the DC brushless motor, so compared with the out-of-step detection using the conventional overcurrent phenomenon, Out-of-synchronization detection can be performed with high precision.

In addition, since the q-axis current Iq corresponding to the output torque component of the current flowing into the motor is proportional to the output torque, detection of out-of-synchronization at the level of the q-axis current may cause erroneous detection. On the other hand, by detecting the AC component of Iq, it is possible to detect out-of-synchronization with higher accuracy even under the condition of different output torques.

In addition, since the variables used in the calculation of the output voltage command value are used in the commutation control device 8, devices such as an induced voltage estimation device are not required, and the out-of-synchronization detection process can be simplified.

Next, another configuration of Embodiment 1 of the synchronous motor out-of-synchronization detection device of the present invention will be described using FIG. 5 . Here, the structure of the commutation device is the same as that in FIG. 1 . The waveform diagram shown in FIG. 5 shows an example of various waveforms when the brushless DC motor 6 is out of step. In FIG. 5, the waveform (a) shows the phase current waveform Iu obtained from the current detection device 7a, the waveform (b) shows the d-axis current waveform Id obtained from the 3-phase 2-phase conversion device 11, and the waveform (c) shows The q-axis current waveform Iq obtained from the 3-phase 2-phase conversion device, the waveform (d) shows the AC component waveform Iq_AC of the q-axis current Iq, and the waveform (e) shows the q-axis current obtained by rectifying the q-axis current AC component Iq_AC Current AC component absolute value waveform |Iq_AC|, waveform (f) shows the waveform Iq_AC_Fil in which the absolute value of the q-axis current AC component is filtered using a low-cut filter.

As shown in Figure 2 and Figure 5, if the DC brushless motor is in a synchronous operation state, the current Id and Iq in the d-q coordinate system are almost DC, and AC components are generated in Id and Iq in the out-of-step state. As shown in the waveform (f) of Figure 3, use a low-pass filter to compare the values Id_AC_Fil and Iq_AC_Fil obtained by filtering the absolute values of the AC components of Id and Iq with the out-of-synchronization detection level Error_Level, and when the value exceeds this value, it is regarded as out-of-synchronization . Out-of-synchronization detection can be performed by such an operation.

Referring to FIG. 6 , as an example of a step-out detection device, a device using a q-axis current Iq corresponding to an output torque component of the current flowing in the motor will be described. FIG. 6 is a flowchart showing the flow of out-of-synchronization detection processing. In Fig. 6, STP1 is out-of-synchronization detection start processing, STP2 is phase current detection processing, STP3 is phase current calculation processing, STP4 is 3-phase 2-phase conversion processing, STP5 is AC component detection processing, and STP10 is rectification (absolute value calculation ) processing, STP11 is the filter processing performed by the low-pass filter, STP12 is the out-of-synchronization level comparison result, STP7 is the PWM stop processing, STP8 is the abnormal end processing, and STP9 is the normal end processing.

The process of out-of-synchronization detection is as follows. Based on the out-of-synchronization detection processing started at STP1, currents Iu and Iv flowing into two phases of the DC brushless motor 6 are detected by the current detection devices 7a and 7b in the phase current detection processing of STP2. In the phase current calculation process of STP3, the currents Iu, Iv, and Iw of the three-phase portion are obtained from the currents Iu, Iv of the two-phase portion obtained at STP2. In the three-phase-to-two-phase conversion process of STP4, the currents Iu, Iv, and Iw of the three-phase portion obtained at STP3 are converted into currents Id, Iq of the d-q coordinate system. In the AC component detection process of STP5, the AC component Iq_AC of the q-axis current Iq obtained at STP4 is detected by a high-pass filter.

The absolute value |Iq_AC| In the filtering process of STP11, use a low-pass filter to filter |Iq_AC|, and obtain the absolute value filtering value Iq_AC_Fil of the AC component of Iq. In the out-of-synchronization level comparison process of STP12, Iq_AC_Fil is compared with the out-of-synchronization level Error_Level, and when Iq_AC_Fil≥Error_Level is regarded as out-of-synchronization, the process proceeds to STP7.

When Iq_AC_Fil<Error_Level, synchronous operation enters STP9. In the PWM stop processing of STP7, when STP6 judges out-of-synchronization, all the PWM signals output by the PWM signal generator 9 are set to stop, and the operation of the commutation control device is stopped. In the abnormal end processing of STP8, the out-of-synchronization detection is abnormally ended as out-of-synchronization. In the normal end processing of STP9, the out-of-synchronization detection processing is terminated as normal operation.

As above, by detecting the change of the d-q axis current during normal operation and when the step is out, it is possible to detect the out-of-step of the DC brushless motor, so compared with the out-of-step detection using the conventional overcurrent phenomenon, Out-of-synchronization detection can be performed with high precision.

In addition, since the q-axis current Iq corresponding to the output torque component of the current flowing into the motor is proportional to the output torque, when simply detecting out-of-step with the level of the q-axis current, it is necessary to adjust The conditional setting of the torque out-of-step level thus becomes a complex structure. However, by detecting the AC component of Iq as in Embodiment 1 of the present invention, it is possible to detect out-of-synchronization with higher accuracy even under conditions of different output torques.

Similarly, even when the d-axis current value is used for out-of-synchronization detection, since the d-axis current value changes according to the operating conditions of the synchronous motor such as the number of revolutions or the load torque, simply using the d-axis current value as conventionally When detecting the out-of-synchronization level, it is necessary to set the out-of-synchronization level according to the conditions of the number of revolutions or the load torque, so it becomes a complicated structure. However, by detecting the AC component of Id as in Embodiment 1 of the present invention, it is possible to detect out-of-synchronization with higher accuracy even under conditions in which the operating states of the synchronous motors are different.

In addition, since the variables used in the calculation of the output voltage command value are used in the commutation control device 8, devices such as an induced voltage estimation device are not required, and the out-of-synchronization detection process can be simplified.

Also, by taking the absolute value of the AC component Iq_AC of the q-axis current as |Iq_AC|, and using the value Iq_AC_Fil obtained by filtering this value with a low-pass filter for out-of-synchronization detection, the out-of-synchronization detection accuracy can be improved as follows. Although the load torque fluctuates sharply or the voltage fluctuation of the DC power supply 1 does not cause an out-of-step state, the AC component Iq_AC of the q-axis current temporarily increases. By using Iq_AC_Fil for the out-of-synchronization detection, it is possible to avoid the situation caused by the above state. False detection of an out-of-sync state.

Here, a setting example for comparing the out-of-synchronization detection level at the time of out-of-synchronization detection will be described. The AC component Iq_AC of the q-axis current value Iq also generates fluctuations due to load torque in the synchronous operation state. However, since the level of Iq_AC that occurs normally is very small compared to the level of Iq_AC that occurs during out-of-synchronization, the setting level can be set to be larger than the level of Iq_AC that occurs normally. When the Iq_AC level that occurs is small. Since there is a large difference in the generation level of Iq_AC between the normal time and the out-of-synchronization time, it can be easily set.

An example of the set value of the out-of-synchronization level will be described below. For a DC non-electric generator with a current of about 0.5A during rated operation, the average value Iq_AC_Fil of the AC component of the q-axis current Iq that occurs when out of step is less than 50% of the effective value of the rated current within the rated operating range , and different from this, the level of the average value Iq_AC_Fil of the AC component of the q-axis current that occurs when out of step is more than 250% of the effective value of the rated current within the rated operating range. Therefore, a method such as setting 200% of the effective value of the rated current as the out-of-synchronization detection level is adopted in consideration of the influence of the fluctuation of the load torque or the fluctuation of the DC voltage.

In addition, another example at the time of setting the out-of-sync level will be described below. As an example of the load of a synchronous motor, for a compressor, especially a single-rotor compressor whose load fluctuates greatly during one rotation, the torque fluctuation caused by the influence of the load fluctuation occurs in the q-axis current Iq The AC component Iq_AC also slightly increases, but the Iq_AC at the time of out-of-synchronization does not increase, and the out-of-synchronization detection level can be set larger than usual.

In the out-of-synchronization detection method shown in Embodiment 1 of the present invention, since the current flowing into the DC motor at low speed is small due to the combination of the commutation device and the brushless DC motor, it is difficult to perform out-of-synchronization during low-speed operation. Conditions for step detection. Such a situation can be detected by accelerating to a constant operating speed immediately after starting. At this time, the out-of-synchronization state continues until detection, but the time is several seconds, and since the current flowing is smaller than that during rated operation, there is almost no adverse effect on the inverter device or the synchronous motor.

In addition, when accelerating and decelerating the DC brushless motor, AC components may be generated in the current values Id and Iq of the d-q coordinate system, which may cause false detection of out-of-step detection. In such a case, the out-of-synchronization detection process can be performed by not performing the out-of-synchronization detection process during acceleration and deceleration, but performing detection outside of the acceleration and deceleration process.

Here, in the flowchart for out-of-synchronization detection shown in FIG. 4 or FIG. 6, when STP5 detects the AC component from the current in the d-q coordinate system, by using a band-pass filter or FFT (Fast Fourier Transform), etc. A device that only detects specific frequency components can improve the accuracy of out-of-synchronization detection. As an example of the specific component, the frequency twice the frequency of the voltage output from the inverter device can be mentioned. This is because, for example, in the case of a 4-pole motor, the current in the d-q coordinate system at the time of out-of-step contains a large number of frequency components twice the rotational frequency of the voltage output from the inverter device. When determining the specific frequency component, as an example, there is a method of determining according to the number of poles of the motor.

As the out-of-synchronization detection method in Embodiment 1, the method using the q-axis current value is described, and the error between the d-axis current value or the d-axis current value command value and the d-axis current, the q-axis current command value and the q-axis current value are used. The error can also perform the same out-of-synchronization detection. Here, the d-axis current command value and the q-axis current command value are command values for appropriately controlling the synchronous motor when driving and controlling the synchronous motor, and are values determined according to the operating conditions of the synchronous motor.

When using the error between the d-axis current command value and the d-axis current, and the error between the q-axis current command value and the q-axis current to perform out-of-step detection, it is calculated by converting the current values of the three phases obtained from the phase current calculation device 10 into d-q The current value of the coordinate system is the error between the d-q coordinate current and the d-q coordinate current command value obtained by the 3-phase 2-phase conversion device 11 as the d-q coordinate conversion device, and the AC component of the obtained d-q axis current error is detected, and the d-q axis is detected. At least one of the AC components of the current error is compared with an arbitrarily set out-of-synchronization level signal to detect out-of-synchronization.

When the q-axis current value is used for out-of-step detection, the q-axis current corresponds to the torque component of the current flowing in the synchronous motor. Therefore, when a large AC component is generated in the q-axis current, the output torque of the motor fluctuates greatly, which corresponds to abnormal operation. Here, even during constant operation, an AC component occurs in the q-axis current due to fluctuations in the load torque, but it is small compared to the AC component generated during out-of-synchronization. As described above, since the change of the q-axis current is related to the operation of the motor, it is easy to distinguish between the normal state and the out-of-step state. Therefore, the device using the q-axis current for out-of-synchronization detection can easily set the out-of-synchronization level.

Also, when the d-axis current is used for out-of-synchronization detection, since the d-axis current generates an AC component at the time of out-of-synchronization similarly to the q-axis current, the out-of-synchronization detection can be performed similarly to the q-axis current.

In addition, in the case of using both the d-axis current and the q-axis current, since out-of-synchronization is detected based on a plurality of pieces of information, the out-of-synchronization detection accuracy will be improved. The same applies to converting the d-axis current value and the q-axis current value into at least one detected quantity other than the d-axis current or the q-axis current by coordinate transformation or an arithmetic expression.

In addition, the d-axis current and the q-axis current generally define the magnetic pole direction of the motor rotor as the d-axis, and define the 90-degree advance phase from the d-axis along the rotation direction as the q-axis. However, when a synchronous motor is driven without a position sensor, it is difficult to accurately detect the d-q axis. Therefore, as a control coordinate system, the axis corresponding to the d-axis is sometimes defined as the δ-axis, and the axis corresponding to the q-axis is defined as is the γ-axis, and of course it can also be realized with the same structure in the δ-γ-axis coordinate system.

In the above-mentioned embodiment, when averaging the AC components of the d-q axis current, by obtaining the absolute value of the AC component of the d-q axis current and filtering the absolute value, the average value of the AC component of the d-q axis current can be obtained. Find the effective value of the AC component of the d-q axis current as the average value of the AC component of the d-q axis current.

Implementation form 2

7 and 8 show Embodiment 2, FIG. 7 shows the structure of the commutation device, and FIG. 8 is a flow of out-of-synchronization detection processing. In Fig. 7, 1 is a DC power supply unit, 2 is an inverter device, 3 is a plurality of switching elements, 3a is a U-phase upper switching element, 3b is a V-phase upper switching element, 3c is a W-phase upper switching element, 3d is a U-phase lower switching element, 3e is a V-phase lower switching element, and 3f is a W-phase lower switching element. 4 is a plurality of freewheeling diodes connected in parallel with a plurality of switching elements 3 , 5 is an inverter main circuit composed of a plurality of switching elements 3 and a plurality of freewheeling diodes 4 , and 6 is a DC brushless motor.

7a is a current detection device that detects one phase current of the current flowing into the DC brushless motor 6, 7b is a current detection device that detects a phase current different from the current detection device 7a, and 8 is a current detection device based on the current detection device 7a, 7b. The detected current value is an inverter control device that controls switching elements 3 in the inverter main circuit 5 on and off.

9 is a PWM signal generating device for generating a PWM signal for on/off controlling the switching element 3 based on the output voltage command value obtained in the inverter control device 8, and 10 is the signal detected by the current detecting device 7a, 7b. The current value of the two-phase part calculates the phase current calculation device of the three-phase current value, and 11 is a three-phase d-q coordinate conversion device that converts the three-phase current value obtained by the phase current calculation device 10 into a current value of the d-q coordinate system. The 2-phase conversion device, 12 is a voltage command value calculation device for obtaining the output voltage command value of the d-q coordinate system for driving the DC brushless motor based on the d-q coordinate system current value obtained by the 3-phase 2-phase conversion device 11, 13 is an output voltage vector computing device for obtaining an output voltage vector from the output voltage command value of the d-q coordinate system obtained by the voltage command value computing device 12, and 14 is a DC voltage detecting device for detecting the DC voltage of the DC power supply 1.

17 is an output voltage abnormality detection device that compares the magnitude of the output voltage vector Vx* |Vx*| Out-of-synchronization detection means for detecting out-of-synchronization.

The operation of the commutation device configured as above will be described with reference to FIG. 7 . In the figure, the inverter device 2 detects the currents of two phases of the phase currents flowing in the DC brushless motor 6 using the current detection devices 7a and 7b. In order to drive the DC brushless motor 6, the commutation control device 8 uses the detected currents of the two phases, such as the U-phase current Iu and the V-phase current Iv, to calculate the voltage value and the voltage output from the main circuit 5 of the converter. A voltage command value such as a phase is output, and a PWM signal for on/off controlling the switching element 3 in the inverter main circuit 5 is output.

In the commutation control device 8, a PWM signal is output by the operation described below. According to the phase current Iu, Iv detected by the current detection device 7a, 7b, the phase current Iu, Iv, Iw of the three-phase part is obtained in the phase current calculation device 10, and the three-phase part is converted by the 3-phase 2-phase conversion device 11 The phase currents Iu, Iv, and Iw are converted into currents Id, Iq in the d-q coordinate system. The voltage command value calculation device 12 calculates the output voltage command values Vd* and Vq* in the d-q coordinate system from the current Id and Iq of the d-q coordinate system, and the output voltage vector calculation device 13 obtains the output voltage command value Vd* from the d-q coordinate system. , Vq* Calculate the output voltage vector Vx* through calculation. The PWM signal generator 9 obtains and outputs a PWM signal for on/off control of the switching element 3 from the DC voltage Vdc obtained by the DC voltage detector 14 and the output voltage vector Vx*.

According to the PWM signal output by the PWM signal generator 9, the switching element 3 in the inverter main circuit 5 is turned on and off. According to the ON/OFF operation of the switching element 3, electric power is supplied from the inverter main circuit 5 to the DC brushless motor 6, and the DC brushless motor is driven.

The output voltage vector Vx* obtained from the output voltage vector computing device 13 is compared with the out-of-step level V_Error_Level after the magnitude of the vector |Vx*| as out of step. On the other hand, if the out-of-synchronization level V_Error_Level is exceeded, the synchronous operation is normally performed.

In the out-of-synchronization detecting means 18, when |Vx*| falls to the out-of-synchronization level V_Error_Level as a result of the processing by the output voltage abnormality detecting means, an abnormal stop signal is output to the PWM signal generating means 9 as an out-of-synchronization. When the PWM signal generator 9 receives the abnormal stop signal, it outputs a signal to turn off all the switching elements 3 in the inverter main circuit 5 to stop the operation of the switching elements. In addition, at the same time, the operation of the commutation control device is also stopped. Out-of-synchronization detection can be performed by such an operation.

An example of an out-of-synchronization detection device according to Embodiment 2 will be described with reference to FIG. 8 . FIG. 8 is a flowchart showing the flow of out-of-synchronization detection processing. In Fig. 8, STP1 is out-of-step detection start processing, STP13 is output voltage vector detection processing, STP14 is output voltage vector size detection processing, STP15 is out-of-step level comparison processing, STP7 is PWM stop processing, STP8 is abnormal end processing , STP9 is the normal end of processing.

Start the out-of-synchronization detection process in STP1, detect the output voltage vector Vx* obtained from the output voltage vector computing device 13 in the output vector detection process of STP13, and obtain the output detected in 13 in the magnitude detection process of the output vector in STP14 The magnitude of the voltage vector |Vx*|. In the out-of-step level ratio processing of STP15, the size of the output voltage vector |Vx*| is compared with the out-of-step level V_Error_Level, and when |Vx*| On the other hand, when |Vx*|>V_Error_Level, it progresses to STP9 as a normal synchronous operation.

In the PWM stop processing of STP7, when it is judged to be out-of-synchronization at STP6, all the PWM signals output by the PWM signal generator 9 are set to a stop state, and then the operation of the commutation control device is stopped. In the abnormal end processing of STP8, the out-of-synchronization detection is abnormally ended as out-of-synchronization. In the normal end processing of STP9, the out-of-synchronization detection processing is terminated as normal operation.

When driving a DC brushless motor, when the necessary output voltage is reduced for continuous synchronous operation, synchronous operation cannot be continued, causing out-of-synchronization. It is therefore possible to detect out-of-synchronization based on this phenomenon. This detection can be realized in the operation shown in the second embodiment. Here, since the magnitude |Vx*| of the output voltage vector differs according to the operating conditions, the out-of-synchronization level V_Error_Level is set according to the operating conditions.

As described above, by detecting the difference between the output voltage vector |Vx*| generated during normal synchronous operation and the time of out-of-step, the out-of-synchronization of the DC brushless motor is detected, so it is different from the conventional out-of-synchronization detection based on the overcurrent phenomenon. In comparison, out-of-synchronization detection can be performed with higher accuracy.

In addition, since the variables used in the calculation of the output voltage command value are used in the commutation control device 8, devices such as an induced voltage estimation device are not required, and the out-of-synchronization detection process can be simplified.

Here, brushless DC motors are mentioned as examples of the synchronous motors of Embodiment 1 and Embodiment 2 of the present invention, but it is of course possible to obtain the same synchronous motors with permanent magnet synchronous motors, synchronous reluctance motors, and switched reluctance motors. Effect.

As an example of a device equipped with the out-of-synchronization detection device of the synchronous motor of the present invention, a compressor driving device of a refrigerator or an air conditioner is mentioned. By being installed in the compressor driving device, it is possible to improve the noise of the compressor that is generated when the step-out continues, the damage of the refrigerant pipe due to the vibration of the compressor, the demagnetization of the magnet used in the rotor of the motor, or the damage caused by the current Problems such as damage to the semiconductor elements of the inverter device caused by the increase. Thereby, a highly reliable refrigerator or air conditioner can be realized.

As an example of a device equipped with the synchronous motor out-of-synchronization detection device of the present invention, a fan drive device of a refrigerator or an air conditioner is mentioned. By being installed in the fan drive device, it is possible to improve the noise of the fan motor generated when the out-of-step continues, the vibration of the fan, the demagnetization of the magnet used in the rotor of the motor, or the semiconductor element of the inverter device due to an increase in current. damage etc. Thereby, a highly reliable refrigerator or air conditioner can be realized.

The synchronous motor out-of-step detection device of the present invention includes a current detection device that detects the current flowing in the synchronous motor; and converts the coordinates of the current signal obtained from the current detection device into an excitation current component (d-axis current) and a torque current. The d-q coordinate transformation device of component (q-axis electric current); The electric current alternating component detecting device of the alternating current component of the d-q axis electric current obtained from the d-q coordinate transforming device; At least The out-of-synchronization detecting device which detects out-of-synchronization by comparing one of them with an arbitrarily set out-of-synchronization level signal can detect out-of-synchronization with high precision with a simplified structure. In addition, it is possible to prevent the demagnetization of the magnet in the rotor caused by the continuation of the out-of-step state or the destruction of the main circuit elements of the inverter due to the increase of the current. In addition, it is also possible to prevent noise or vibration of the synchronous motor caused by the continuous out-of-step state.

In addition, the synchronous motor out-of-step detection device of the present invention includes a current detection device that detects the current flowing in the synchronous motor; and converts the coordinates of the current signal obtained from the current detection device into an excitation current component (d-axis current) and a rotational speed. The d-q coordinate conversion device of the moment current component (q-axis current); the current AC component detection device for obtaining the d-q axis current AC component obtained from the d-q coordinate conversion device; the d-q axis current AC component detection device obtained from the current AC component detection device The average value of the effective value or the absolute value, the AC component averaging device that averages the AC components of the d-q axis current; at least one of the average values of the d-q axis current AC components obtained from the AC component averaging device and the arbitrarily set out-of-step voltage The out-of-synchronization detecting device which detects the out-of-synchronization by comparing the flat signal can detect the out-of-synchronization with high precision with a simplified structure. In addition, since the averaged value is used as the value used for detection, it is possible to prevent out-of-step detection errors due to load torque fluctuations or voltage fluctuations of the synchronous motor. In addition, it is possible to prevent the demagnetization of the magnet in the rotor caused by the continuation of the out-of-step state or the destruction of the main circuit elements of the inverter due to the increase of the current. In addition, it is also possible to prevent noise or vibration of the synchronous motor caused by the continuous out-of-step state.

In addition, the synchronous motor out-of-step detection device of the present invention includes a current detection device that detects the current flowing in the synchronous motor; and converts the coordinates of the current signal obtained from the current detection device into an excitation current component (d-axis current) and a rotational speed. d-q coordinate conversion device for the moment current component (q-axis current); a current error calculation device for calculating the error between the d-q coordinate current obtained from the d-q coordinate conversion device and the d-q coordinate current command value; detecting the d-q axis current obtained from the current error calculation device A current error AC component detection device for the AC component of the error; at least one side of the d-q axis current error AC component obtained from the current error AC component detection device is compared with an arbitrarily set out-of-step level signal to detect out-of-synchronization The detection device can detect out-of-synchronization with high precision with a simplified structure. In addition, it is possible to prevent the demagnetization of the magnet in the rotor caused by the continuation of the out-of-step state or the destruction of the main circuit elements of the inverter due to the increase of the current. In addition, it is also possible to prevent noise or vibration of the synchronous motor caused by the continuous out-of-synchronization state.

In addition, the out-of-synchronization detecting device of the synchronous motor according to the present invention can improve the out-of-synchronization detection accuracy by detecting only a specific frequency component when detecting an AC component from a d-q coordinate system current.

In addition, the out-of-synchronization detection device of the synchronous motor of the present invention can improve the out-of-synchronization detection accuracy by setting a specific frequency component to twice the frequency of the voltage output from the inverter device.

In addition, the out-of-synchronization detection device of the synchronous motor of the present invention can improve the out-of-synchronization detection accuracy by detecting only a specific frequency component when detecting the AC component of the d-q axis current error.

In addition, the out-of-synchronization detection device of the synchronous motor of the present invention takes about 200% of the rated current of the synchronous motor by comparing the out-of-synchronization detection level with the average value of the AC component of the q-axis current, and can be independent of load torque or DC voltage. The effects of changes and out-of-synchronization are reliably detected.

In addition, the synchronous motor out-of-synchronization detection device of the present invention can detect out-of-synchronization by accelerating to a constant operating speed immediately after starting and detecting out-of-synchronization when it is difficult to detect out-of-synchronization at low speeds.

In addition, the out-of-synchronization detecting device of the synchronous motor of the present invention can detect the out-of-synchronization by performing the out-of-synchronization detection process outside the process of acceleration and deceleration when the synchronous motor is accelerated and decelerated. .

In addition, the synchronous motor out-of-step detection device of the present invention is provided with a current detection device for detecting the current flowing in the synchronous motor in a commutation device that drives the synchronous motor without using a position sensor for detecting the rotor position; according to The current signal obtained by the current detection device is used to calculate the output voltage command value computing device for the output voltage command value added to the synchronous motor; the output voltage vector computing device is used to calculate the output voltage vector according to the output voltage command value obtained from the output voltage command computing device; The output voltage abnormality detection device that compares the magnitude of the output voltage vector obtained from the output voltage vector calculation device with the out-of-step detection level; the out-of-synchronization detection device that detects out-of-synchronization according to the comparison result obtained from the output voltage abnormality detection device, can With a simplified structure, out-of-synchronization is detected with high precision. In addition, it is possible to prevent the demagnetization of the magnet in the rotor caused by the continuation of the out-of-step state or the destruction of the main circuit elements of the inverter due to the increase of the current. In addition, it is also possible to prevent noise or vibration of the synchronous motor caused by the continuous out-of-step state.

In addition, in the synchronous motor out-of-step detection method of the present invention, in the commutation device that drives the synchronous motor without using a position sensor for detecting the rotor position, by including a current detection step of detecting the current flowing in the synchronous motor; The coordinate transformation of the current signal obtained in the current detection step is the d-q coordinate transformation step of the excitation current component (d-axis current) and the torque current component (q-axis current); the current of the AC component of the d-q axis current obtained from the d-q coordinate transformation step AC component detection step; at least one of the above-mentioned d-q axis current AC components obtained from the current AC component detection step is compared with an arbitrarily set out-of-synchronization level signal to detect out-of-synchronization detection steps, which can be simplified in structure , to detect out-of-synchronization with high precision. In addition, it is possible to prevent the demagnetization of the magnet in the rotor caused by the continuation of the out-of-step state or the destruction of the main circuit elements of the inverter due to the increase of the current. In addition, it is also possible to prevent noise or vibration of the synchronous motor caused by the continuous out-of-step state.

In addition, in the synchronous motor out-of-step detection method of the present invention, in the commutation device that drives the synchronous motor without using a position sensor for detecting the rotor position, by including a current detection step of detecting the current flowing in the synchronous motor; The coordinate transformation of the current signal obtained in the current detection step is the d-q coordinate transformation step of the excitation current component (d-axis current) and the torque current component (q-axis current); the current of the AC component of the d-q axis current obtained from the d-q coordinate transformation step AC component detection step; seek the effective value or the average value of the absolute value of the d-q axis current AC component obtained from the current AC component detection step, and the AC component average step of averaging the d-q axis current AC component; obtain from the AC component average step The out-of-synchronization detection step of comparing at least one of the average values of the d-q axis current AC components with an arbitrarily set out-of-synchronization level signal can detect out-of-synchronization with a simplified structure and with high precision. In addition, since the averaged value is used as the value used for detection, it is possible to prevent out-of-step detection errors due to load torque fluctuations or voltage fluctuations of the synchronous motor. In addition, it is possible to prevent the demagnetization of the magnet in the rotor caused by the continuation of the out-of-step state or the destruction of the main circuit elements of the inverter due to the increase of the current. In addition, it is also possible to prevent noise or vibration of the synchronous motor caused by the continuous out-of-synchronization state.

In addition, in the synchronous motor out-of-step detection method of the present invention, in the commutation device that drives the synchronous motor without using a position sensor for detecting the rotor position, by including a current detection step of detecting the current flowing in the synchronous motor; The coordinate transformation of the current signal obtained in the current detection step is the d-q coordinate transformation step of the excitation current component (d-axis current) and the torque current component (q-axis current); the d-q coordinate current and the d-q coordinate current command obtained from the d-q coordinate transformation step The current error calculation step of the error of the value; the current error AC component detection step of the d-q axis current error AC component detection step obtained from the current error calculation step; at least the d-q axis current error AC component detection step obtained from the current error AC component detection step The out-of-synchronization detection step of detecting out-of-synchronization by comparing one of them with an arbitrarily set out-of-synchronization level signal can detect out-of-synchronization with high accuracy with a simplified structure. In addition, it is possible to prevent the demagnetization of the magnet in the rotor caused by the continuation of the out-of-step state or the destruction of the main circuit elements of the inverter due to the increase of the current. In addition, it is also possible to prevent noise or vibration of the synchronous motor caused by the continuous out-of-synchronization state.

In addition, the out-of-synchronization detection method of a synchronous motor according to the present invention can improve the out-of-synchronization detection accuracy by detecting only a specific frequency component when detecting an AC component from a d-q coordinate system current.

In addition, the out-of-synchronization detection method of the synchronous motor of the present invention can improve the out-of-synchronization detection accuracy by setting a specific frequency component as twice the frequency of the voltage output from the inverter device.

In addition, the out-of-synchronization detection method of the synchronous motor of the present invention can improve the out-of-synchronization detection accuracy by detecting only a specific frequency component when detecting the AC component of the d-q axis current error.

In addition, the out-of-synchronization detection method of the synchronous motor of the present invention takes about 200% of the rated current of the synchronous motor by comparing the out-of-synchronization detection level with the average value of the AC component of the q-axis current, and can be independent of load torque or DC voltage. The effects of changes and out-of-synchronization are reliably detected.

In addition, in the synchronous motor out-of-step detection method of the present invention, when it is difficult to detect out-of-synchronization at low speeds, the out-of-synchronization detection can be performed by accelerating to a constant operating speed immediately after starting to detect the out-of-synchronization. Perform out-of-sync detection.

In addition, the out-of-synchronization detection method of the synchronous motor of the present invention can detect the out-of-synchronization by performing the out-of-synchronization detection process outside the process of acceleration and deceleration when the synchronous motor is accelerated and decelerated. .

In addition, in the synchronous motor out-of-step detection method of the present invention, in a commutation device that drives a synchronous motor without using a position sensor for detecting the rotor position, a current detection step for detecting the current flowing in the synchronous motor is provided; an output voltage command value calculation step for calculating the output voltage command value added to the synchronous motor from the current signal obtained in the current detection step; an output voltage vector calculation step for calculating an output voltage vector according to the output voltage command value obtained from the output voltage command calculation step; The output voltage abnormality detection step of comparing the magnitude of the output voltage vector obtained from the output voltage vector calculation step with the out-of-synchronization detection level; the out-of-synchronization detection step of detecting out-of-synchronization based on the comparison result obtained from the output voltage abnormality detection step, can With a simplified structure, out-of-synchronization is detected with high precision. In addition, it is possible to prevent the demagnetization of the magnet in the rotor caused by the continuation of the out-of-step state or the destruction of the main circuit elements of the inverter due to the increase of the current. In addition, it is also possible to prevent noise or vibration of the synchronous motor caused by the continuous out-of-synchronization state.

The driving device of the hermetic compressor of the present invention is equipped with the out-of-step detection device of the synchronous motor of the present invention, which can improve the compressor noise generated when the out-of-step continues, and the damage of the refrigeration pipe caused by the vibration of the compressor. Demagnetization of the magnets used in the rotor of the motor or damage to the semiconductor elements of the inverter due to the increase in current. Thereby, a highly reliable refrigerator or air conditioner can be realized.

The driving device of the fan motor of the present invention is equipped with the out-of-synchronization detection device of the synchronous motor of the present invention, which can improve the noise of the fan motor generated when the out-of-step continues, the vibration of the fan, and the loss of the magnet used in the rotor of the motor. Magnetism or damage to the semiconductor elements of the inverter due to the increase in current. Thereby, a highly reliable refrigerator or air conditioner can be realized.

Claims (22)

1. A synchronous motor out-of-step detection device used in a converter device, the above-mentioned converter device does not use a position sensor for detecting the rotor position to drive the synchronous motor, the out-of-step detection device is characterized in that it has: a current detection unit for detecting a current flowing in the aforementioned synchronous motor; A d-q coordinate conversion unit that converts the coordinates of the current signal obtained from the above-mentioned current detection unit into a d-axis current representing an excitation current component and a q-axis current representing a torque current component; A current alternating component detection unit that obtains the alternating components of the d-axis current and the q-axis current obtained from the d-q coordinate transformation unit through a high-pass filter; An out-of-synchronization detecting unit that detects out-of-synchronization by comparing at least one of the alternating current components of the d-axis current and the q-axis current obtained from the current alternating-current component detecting unit with an arbitrarily set out-of-synchronization level signal. 2. A synchronous motor out-of-step detection device used in a converter device, the above-mentioned converter device does not use a position sensor for detecting the position of the rotor to drive the synchronous motor, the out-of-step detection device is characterized in that it has: a current detection unit for detecting a current flowing in the aforementioned synchronous motor; A d-q coordinate conversion unit that converts the coordinates of the current signal obtained from the above-mentioned current detection unit into a d-axis current representing an excitation current component and a q-axis current representing a torque current component; A current alternating component detection unit that obtains the alternating components of the d-axis current and the q-axis current obtained from the d-q coordinate transformation unit through a high-pass filter; An AC component averaging unit that averages the AC components of the d-axis current and the q-axis current by obtaining the average value of the effective value or absolute value of the AC components of the d-axis current and the q-axis current obtained from the current AC component detection unit; Out-of-synchronization detecting means for detecting out-of-synchronization by comparing at least one of the average values of the AC components of the d-axis current and the q-axis current obtained from the AC component averaging means with an arbitrarily set out-of-synchronization level signal. 3. The out-of-step detection device of a synchronous motor according to claim 1 or 2, characterized in that: When the above-mentioned current AC component detection unit detects an AC component, only a specific frequency component is detected. 4. The out-of-step detection device of a synchronous motor according to claim 3, characterized in that: The above-mentioned specific frequency component is taken as twice the frequency of the voltage frequency output by the above-mentioned converter device. 5. The out-of-step detection device of a synchronous motor according to claim 2, characterized in that: The out-of-synchronization level signal to be compared with the average value of the AC component of the q-axis current is set to be 200% or more of the rated current of the synchronous motor. 6. A synchronous motor out-of-step detection device used in a converter device, the above-mentioned converter device does not use a position sensor for detecting the rotor position to drive the synchronous motor, the out-of-step detection device is characterized in that it has: a current detection unit for detecting a current flowing in the aforementioned synchronous motor; A d-q coordinate conversion unit that converts the coordinates of the current signal obtained from the above-mentioned current detection unit into a d-axis current representing an excitation current component and a q-axis current representing a torque current component; A current error calculation unit that obtains two errors, an error between the d-axis current and the d-axis current command value obtained from the d-q coordinate conversion unit, and an error between the q-axis current and the q-axis current command value; A current error AC component detection unit that detects the AC components of the above-mentioned two errors obtained from the above-mentioned current error calculation unit through a high-pass filter; Out-of-synchronization detection means for detecting out-of-synchronization by comparing at least one of the AC components of the two errors obtained from the current error AC component detection means with an arbitrarily set out-of-synchronization level signal. 7. The out-of-step detection device of a synchronous motor according to claim 6, characterized in that: When the above-mentioned current error AC component detection unit detects an AC component, only a specific frequency component is detected. 8. The out-of-step detection device of a synchronous motor according to any one of claims 1, 2, and 6, characterized in that: When it is difficult to detect out-of-step at low speeds, the out-of-step detection is performed by accelerating to a constant operating speed immediately after starting. 9. The out-of-step detection device of a synchronous motor according to any one of claims 1, 2, and 6, characterized in that: When the synchronous motor is accelerated or decelerated, if a false detection of the out-of-synchronization detection may occur, the out-of-synchronization detection process is performed outside of the acceleration process or during the deceleration process. 10. A synchronous motor out-of-step detection device used in a converter device, the above-mentioned converter device does not use a position sensor for detecting the rotor position to drive the synchronous motor, the out-of-step detection device is characterized in that it has: a current detection unit for detecting a current flowing in the aforementioned synchronous motor; an output voltage command value calculation unit for obtaining an output voltage command value added to the above-mentioned synchronous motor based on the current signal obtained from the above-mentioned current detection unit; An output voltage vector operation unit for obtaining an output voltage vector according to an output voltage command value obtained from the above output voltage command operation unit; an output voltage abnormality detection unit that compares the magnitude of the output voltage vector obtained from the output voltage vector operation unit with the out-of-synchronization detection level; An out-of-synchronization detection unit that detects out-of-synchronization based on the comparison result obtained from the above-mentioned output voltage abnormality detection unit. 11. A method for detecting out-of-synchronization of a synchronous motor used in a converter device, wherein the above-mentioned converter device does not use a position sensor for detecting the position of the rotor to drive the synchronous motor, the method for detecting out-of-synchronization is characterized in that it has: a current detecting step of detecting a current flowing in the synchronous motor; a d-q coordinate transformation step of transforming the coordinates of the current signal obtained from the above-mentioned current detection step into a d-axis current representing an excitation current component and a q-axis current representing a torque current component; A current AC component detection step for obtaining the AC components of the d-axis current and the q-axis current obtained from the above-mentioned d-q coordinate transformation step through a high-pass filter; an out-of-synchronization detection step for detecting out-of-synchronization by comparing at least one of the alternating current components of the d-axis current and the q-axis current obtained in the current alternating-current component detection step with an arbitrarily set out-of-synchronization level signal. 12. A method for detecting out-of-synchronization of a synchronous motor used in a converter device, wherein the above-mentioned converter device does not use a position sensor for detecting the position of the rotor to drive the synchronous motor, the method for detecting out-of-synchronization is characterized in that it has: a current detecting step of detecting a current flowing in the synchronous motor; a d-q coordinate transformation step of transforming the coordinates of the current signal obtained from the above-mentioned current detection step into a d-axis current representing an excitation current component and a q-axis current representing a torque current component; A current AC component detection step for obtaining the AC components of the d-axis current and the q-axis current obtained from the above-mentioned d-q coordinate transformation step through a high-pass filter; Finding the average value of the effective value or absolute value of the AC components of the d-axis current and the q-axis current obtained from the above current AC component detection step, and averaging the AC components of the d-q axis current AC components; An out-of-synchronization detection step for detecting out-of-synchronization by comparing at least one of the average values of the d-axis current and the q-axis current obtained in the above-mentioned alternating-current component averaging step with an arbitrarily set out-of-synchronization level signal. 13. The out-of-step detection method of a synchronous motor according to claim 11 or 12, characterized in that: When the above-mentioned current AC component detecting step detects AC components, only specific frequency components are detected. 14. The out-of-step detection method of a synchronous motor according to claim 13, characterized in that: The above-mentioned specific frequency component is taken as twice the frequency of the voltage frequency output by the above-mentioned converter device. 15. The out-of-step detection method of a synchronous motor according to claim 12, characterized in that: The out-of-synchronization level signal to be compared with the average value of the AC component of the q-axis current is set to be 200% or more of the rated current of the synchronous motor. 16. A method for detecting out-of-synchronization of a synchronous motor used in a converter device, wherein the above-mentioned converter device does not use a position sensor for detecting the position of the rotor to drive the synchronous motor, the method for detecting out-of-synchronization is characterized in that it has: a current detecting step of detecting a current flowing in the synchronous motor; a d-q coordinate transformation step of transforming the coordinates of the current signal obtained from the above-mentioned current detection step into a d-axis current representing an excitation current component and a q-axis current representing a torque current component; A current error calculation step for obtaining two errors of an error between the d-axis current and the d-axis current command value obtained from the above d-q coordinate transformation step, and an error between the q-axis current and the q-axis current command value; A current error AC component detection step for detecting the AC components of the above-mentioned two errors obtained from the above-mentioned current error operation step; The out-of-synchronization detecting step of comparing at least one of the AC components of the two errors obtained from the above-mentioned current error AC component detecting step with an arbitrarily set out-of-synchronization level signal to detect out-of-synchronization. 17. The out-of-step detection method of a synchronous motor according to claim 16, characterized in that: When the above current error AC component detection step detects AC components, only specific frequency components are detected. 18. The out-of-step detection method of a synchronous motor according to any one of claims 11, 12, 16, characterized in that: When it is difficult to detect out-of-step at low speeds, the out-of-step detection is performed by accelerating to a constant operating speed immediately after starting. 19. The out-of-step detection method of a synchronous motor according to any one of claims 11, 12, 16, characterized in that: When the synchronous motor is accelerated or decelerated, if a false detection of the out-of-synchronization detection may occur, the out-of-synchronization detection process is performed outside of the acceleration process or during the deceleration process. 20. A method for detecting out-of-synchronization of a synchronous motor used in a converter device, wherein the above-mentioned converter device does not use a position sensor for detecting the position of the rotor to drive the synchronous motor, the method for detecting out-of-synchronization is characterized in that it has: a current detecting step of detecting a current flowing in the synchronous motor; an output voltage command value operation step of obtaining an output voltage command value added to the above-mentioned synchronous motor based on the current signal obtained from the above-mentioned current detection step; An output voltage vector calculation step for obtaining an output voltage vector according to the output voltage command value obtained from the above output voltage command calculation step; an output voltage abnormality detection step of comparing the magnitude of the output voltage vector obtained from the above output voltage vector calculation step with the out-of-synchronization detection level; An out-of-synchronization detection step of detecting out-of-synchronization based on the comparison result obtained from the above-mentioned output voltage abnormality detection step. 21. A driving device for a hermetic compressor, characterized in that: The out-of-synchronization detecting device of a synchronous motor according to any one of claims 1 to 10 is mounted. 22. A driving device for a fan motor, characterized in that: The out-of-synchronization detecting device of a synchronous motor according to any one of claims 1 to 10 is mounted.

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