JP2018174655A - Control apparatus and control method for rotary machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control apparatus for rotary machine, capable of achieving suppression in an error between a control operation amount to be controlled and a true value to be essentially controlled even when current control is under a current change or includes a harmonic wave.SOLUTION: The control apparatus executes the following steps: sampling an AC current of each of three phases in 60° periodicity N times; determining an addition average of d-axis and q-axis currents obtained by 3-phase/2-phase converting the sampled AC currents; calculating an effective value from the addition average to determine a current detection effective value (1)-(8); calculating a current command effective value on the basis of a torque command and a rotational speed; applying PI control to a deviation between the current detection effective value and the current command effective value to generate a voltage command corresponding to the deviation (9)-(16); calculating a developed formula of fourier series based on the voltage command to determine a pulse string phase; creating a phase voltage command of three phases on the basis of pulse string information and a current phase command (18); and on-off controlling a switching element of an inverter using the created command.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rotating machine control device for controlling a rotating machine, and more particularly to a rotating machine control device that performs overmodulation PWM (pulse width modulation) control.

Conventionally, a control device described in Patent Document 1 has been proposed as a device for controlling an applied voltage of a rotating machine, for example, an AC motor, using an inverter. This Patent Document 1 discloses a modulation represented by FM = (Vd # ² + Vq # ² ) ^1/2 / VH from the input voltage VH of the inverter 14 and the voltage command values Vd # and Vq # generated by the voltage command generator 240. It is described that the rate FM is obtained and control is switched to sine wave PWM control, overmodulation PWM control, or rectangular wave voltage control according to the modulation rate FM (paragraphs 0067 to 0076 of Patent Document 1).

  FIG. 5 (FIG. 2 of Patent Document 1) showing the output voltage waveform for each modulation region: From the linear region (sine wave PWM control) to the overmodulation region (overmodulation PWM control) to one pulse region (rectangular wave voltage control). It is known that the output voltage of the inverter deviates from the sine wave and the harmonic component of the actual current increases as the number of switching operations for performing voltage control decreases as the transition occurs.

  For this reason, in the current control using the conventional instantaneous current, the filtering process by the current filter for removing the distortion component from the detected motor current is executed (paragraphs 0083 and 0086 to 0088 of Patent Document 1).

  However, this filtering process can remove harmonic components superimposed on the motor current, but the actual current (detected) when the d and q axis current command changes greatly, such as when the control mode is switched or when the current command is suddenly changed. The magnitude relationship between (current) Id and Iq and the current command values Idcom and Iqcom is reversed, and control may diverge and become unstable (paragraphs 0099 and 0100 of Patent Document 1).

  Therefore, in Patent Document 1, control instability is prevented by taking the following measures (1) to (3).

  (1) A filter process for smoothing the voltage command values Vd # and Vq # having a time constant τv larger than the time constant τc of the filter process by the current filter 230 is performed (paragraphs 0103 to 0125 of Patent Document 1).

  (2) A filter process for smoothing the amplitude | V | and the voltage phase Vφ of the voltage command values Vd # and Vq # is performed (paragraphs 0127 to 0137 of Patent Document 1).

  (3) The voltage command values Vd # and Vq # are calculated from the current command values Idcom and Iqcom by correction calculation by feedforward control based on the motor voltage equation (paragraphs 0147 to 0153 in Patent Document 1).

JP 2010-88205 A

  However, there is a delay in current control response due to the use of the filter processing and correction calculation described in Patent Document 1, and a reduction in processing speed due to a complicated control loop, so that there is a gap between the current command and the actual current (current detection). There is a problem that an error occurs and the control operation amount to be controlled is far from the true value that should be controlled.

  The present invention solves the above-mentioned problems, and the purpose thereof is a true value that must be controlled with the amount of control operation that is to be controlled, even in the case of current control during current change or including harmonics. It is an object of the present invention to provide a control device and method for a rotating machine that can suppress the error of the rotating machine.

The control device for a rotating machine according to claim 1 for solving the above problem is a control device for a rotating machine that controls an applied voltage of the rotating machine by an inverter that converts a DC voltage into an AC voltage,
At the time of overmodulation control by synchronous pulse width modulation, in synchronization with a set number of magnetic pole phase values obtained by detecting the magnetic pole position of the rotating machine for each set period, the three-phase AC current of the inverter is detected a set number of times, The detected number of set three-phase AC current values are converted into three-phase / two-phase coordinates based on the set number of magnetic pole phase values to obtain a set number of d-axis current values and a set number of q-axis current values. Point current sample acquisition means;
Current detection effective value calculation means for calculating an addition average value of the obtained set number of d-axis current values and a set number of q-axis current values and calculating a current detection effective value from each of the addition average values; ,
Current command effective value calculation means for calculating a current command effective value based on the requested torque command and the rotation speed of the rotating machine calculated from the magnetic pole phase value obtained by detecting the magnetic pole position of the rotating machine;
Current phase command output means for outputting a current phase command corresponding to the torque command and the rotational speed of the rotating machine;
The deviation between the current detection effective value calculated by the current detection effective value calculation means and the current command effective value calculated by the current command effective value calculation means is subjected to PI (proportional integration) control to obtain the deviation. Voltage command generation means for generating a voltage command according to
A pulse series phase is obtained by calculating a Fourier series expansion formula based on the voltage command generated by the voltage command generating means, a width of the pulse train is calculated from the voltage command and the set number of synchronous pulses, and the width of the pulse train and the pulse train From the phase, the rising phase and the falling phase of the three-phase pulse train are determined, and based on the pulse train information and the current phase command output from the current phase command output means, the three-phase phase voltage command Vu ^* , Synchronization pulse width modulation signal generating means for generating Vv ^* and Vw ^* ,
The switching elements of the inverter are controlled to be turned on / off by three-phase phase voltage commands Vu ^* , Vv ^* , Vw ^* generated by the synchronous pulse width modulation signal generating means.

The control device for a rotating machine according to claim 2 is the control device according to claim 1,
The voltage command generated according to the voltage command generation means is multiplied by the waveform rate determined by the number of synchronization pulses and the pulse width obtained by FFT (Fast Fourier Transform) analysis as a correction manipulated variable, Synchronous pulse width modulation voltage correcting means for generating a voltage command and outputting it to the synchronous pulse width modulation signal generating means is provided.

According to a third aspect of the present invention, there is provided the control apparatus for a rotating machine according to the first or second aspect, wherein the current phase command output means includes a d-axis current command and a q-axis current command obtained from the torque command and the rotational speed of the rotating machine. A phase command table storing a current phase command calculated from the ratio of the torque command and the rotational speed of the rotating machine,
A current phase command corresponding to the torque command and the rotation speed of the rotating machine is output with reference to the phase command table.

The method for controlling a rotating machine according to claim 4 is a method for controlling a rotating machine in which an applied voltage of the rotating machine is controlled by an inverter that converts a DC voltage into an AC voltage,
The multi-point current sample acquisition means synchronizes with the set number of magnetic pole phase values obtained by detecting the magnetic pole position of the rotating machine for each set period during overmodulation control by synchronous pulse width modulation, A set number of d-axis current values and a set number are detected by detecting the set number of AC currents and converting the three-phase AC current value of the set number of detected times to three-phase / two-phase coordinates based on the set number of magnetic pole phase values. A multi-point current sample acquisition step for obtaining a q-axis current value of
The current detection effective value calculation means obtains the addition average value of the obtained set number of d-axis current values and the addition average value of the set number of q-axis current values, and calculates the current detection effective value from each of the addition average values. Current detection effective value calculation step to perform,
The current command effective value calculation means calculates the current command effective value based on the requested torque command and the rotation speed of the rotating machine calculated from the magnetic pole phase value obtained by detecting the magnetic pole position of the rotating machine. A value calculation step;
A current phase command output step, wherein the current phase command output means outputs a current phase command corresponding to the torque command and the rotational speed of the rotating machine;
The voltage command generating means is PI (proportional integral) with respect to a deviation between the current detection effective value calculated by the current detection effective value calculation means and the current command effective value calculated by the current command effective value calculation means. A voltage command generation step for generating a voltage command according to the deviation by performing control;
Synchronous pulse width modulation signal generating means calculates a pulse train phase by calculating a Fourier series expansion formula based on the voltage command generated by the voltage command generating means, and calculates the width of the pulse train from the voltage command and the set number of synchronous pulses. Then, the rising phase and falling phase of the pulse train of each of the three phases are determined from the width of the pulse train and the pulse train phase, and based on the pulse train information and the current phase command output from the current phase command output means, A synchronous pulse width modulation signal generation step for generating three phase voltage commands Vu ^* , Vv ^* , Vw ^* ,
The switching element of the inverter is controlled to be turned on / off by the three-phase phase voltage commands Vu ^* , Vv ^* , Vw ^* generated in the synchronous pulse width modulation signal generation step.

The method for controlling a rotating machine according to claim 5 is the method according to claim 4,
The voltage correction means for synchronizing pulse width modulation multiplies the voltage command generated by the voltage command generating means by the waveform rate determined by the number of synchronizing pulses and the pulse width obtained by FFT analysis as a correction operation amount. And a voltage correction step for synchronizing pulse width modulation for generating a corrected voltage command and outputting the voltage command to the synchronizing pulse width modulation signal generating means.

The method for controlling a rotating machine according to claim 6 is the method according to claim 4 or 5,
In the current phase command output step, the current phase command calculated from the ratio of the d-axis current command and the q-axis current command obtained from the torque command and the rotational speed of the rotating machine is converted into the torque command and the rotating speed of the rotating machine. With reference to the phase command table stored correspondingly, a current phase command corresponding to the torque command and the rotational speed of the rotating machine is output.

(1) According to the first to sixth aspects of the present invention, it is possible to suppress an error between a control operation amount to be controlled and a true value that must be controlled at the time of overmodulation control by synchronous pulse width modulation. , Stable control can be performed.

In prior arts such as Patent Document 1, since instantaneous current is detected by a filter, there is a large deviation from the actual detected current value, and there is no control periodicity. However, in the method using the average value of the multi-point current sample of the present invention, the detection accuracy can be improved within the range of the detectable resolution (N times), and the current control with 60 ° periodicity can be protected. I can do it. Therefore, current control more stable than the prior art can be constructed.
(2) According to the inventions of claims 2 and 4, since the voltage command is corrected using the waveform rate determined by the number of periodic pulses and the pulse width obtained by FFT analysis as a correction operation amount, in the overmodulation region, The difference between the control operation amount and the control true value due to the increase of the harmonic component can be corrected.
(3) According to the third and sixth aspects of the invention, since the current phase command is configured to be output with reference to the phase command table, the control processing is simplified and the processing speed is improved. be able to.

1 is a configuration diagram of a motor control device according to an embodiment of the present invention. The control block diagram by one example embodiment of this invention. Explanatory drawing which shows the mode of the pulse train generation in the synchronous pulse width modulation signal generation means of the example of one embodiment of the present invention. The timing of current detection and current control is shown, (a) is an explanatory diagram of the same timing system, (b) is an explanatory diagram of the system of the present invention. The output voltage waveform figure for every modulation area | region in motor control. Explanatory drawing which shows the timing of an electric current detection and electric current control to sine wave PWM control.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments.

  FIG. 1 shows the configuration of the motor control device of this embodiment. In FIG. 1, reference numeral 50 denotes a motor control device, which includes an inverter 50a and a control unit 50b. A storage battery 51 is connected to the direct current side of the motor control device 50, and a motor 52 (for example, a PM motor (Permanent Magnet Motor)) is connected to the alternating current side.

  Further, a DC voltage detection sensor 53 for detecting a DC voltage detection value is applied to the DC bus of the inverter 50a, and AC current detection sensors 54a, 54c for detecting an AC current detection value are applied to the U phase and W phase of the AC bus of the inverter 50a. The motor 52 is provided with a magnetic pole position sensor 55 (for example, a resolver) that detects a rotation speed detection value of the motor 52.

  The controller 50b receives a torque command value from the outside of the apparatus, a DC voltage detection value from the DC voltage detection sensor 53, an AC current detection value from the AC current detection sensors 54a and 54c, and a rotation angle detection value from the magnetic pole position sensor 55.

  The controller 50b does not show a desired voltage command value by vector control based on these torque command values and detection values from various sensors (DC voltage detection sensor 53, AC current detection sensors 54a and 54c, and magnetic pole position sensor 55). Output to the gate drive circuit.

  In the gate drive circuit, a gate signal based on the input voltage command value is output to the inverter 50a, and the switching element (IGBT in the example of FIG. 1) is turned on / off.

  The motor control device 50 performs motor control by converting the DC voltage of the storage battery 51 into a desired AC voltage and outputting it to the motor 52 by an inverter 50 a having a switching element.

  In FIG. 1, the storage battery 51 is connected to the DC side of the motor control device 50, but a configuration in which DC power is obtained from an AC power supply by forward conversion using a rectifier may be used. Moreover, although the alternating current detection sensors 54a and 54c obtain three-phase alternating current from the two phases of the U phase and the W phase by calculation, the alternating current detection sensor 54b is also provided in the V phase, and the U phase, V phase, and It may be configured to detect the current of each phase of the W phase.

  The control part 50b is comprised by the control block provided with the detection block and command block of FIG. In FIG. 2, the detection block includes the following sections (1) to (8).

(1) U-phase current detector (Iudet (N times))
The detected current of the U-phase current detection sensor 54a on the AC output side of the motor control device 50 (for example, the current detected by the current transformer CT) is synchronized with the magnetic pole phase θdet sampled by (3) magnetic pole phase detector described later. The result A (Iu _1det , Iu _2det , Iu _3det ,... Iu _Ndet ) sampled N times is stored in the memory.

As a result, A holds U phase currents (Iu _1det , Iu _2det , Iu _3det ,... Iu _Ndet ) from 1 to N times detected for each set period.

(2) V-phase current detector (Ivdet (N times))
From the detected current of the V-phase current detection sensor 54b on the AC output side of the motor control device 50 (for example, the current detected by the current transformer CT) or the V-phase current obtained by calculation from the detected currents of the U-phase and the W-phase. The result B (Iv _1det , Iv _2det , Iv _3det ,... Iv _Ndet ) sampled N times in synchronization with the magnetic pole phase θdet sampled by the magnetic pole phase detector described later is stored in the memory.

As a result, the B holds the V-phase currents (Iv _1det , Iv _2det , Iv _3det ,... Iv _Ndet ) from 1 to N times detected for each set cycle.

(3) Magnetic pole phase detector (θdet (N times))
A result C (θ _1det , θ _2det , θ _3det ,..., Θ _Ndet ) obtained by sampling the magnetic pole phase detection θdet from the resolver (magnetic pole position sensor 55 shown in FIG. 1) N times for each set period is stored in the memory.

As a result, the magnetic pole phase detection (θ _1det , θ _2det , θ _3det ,..., Θ _Ndet ) from the _1st to the _Nth times detected for each set period is held.

(4) 3-phase / 2-phase converter (executed N times)
Using the results A to C, the three-phase / two-phase conversion circuit performs N-phase three-phase / two-phase coordinate conversion, and results N (d-axis current detection Id _1det , Id _2det , Id _3det ,... Id _Ndet and q-axis current detections Iq _1det , Iq _2det , Iq _3det ,... Iq _Ndet ) are output.

(5) d-axis current detector (Id_det (N times))
Among the results D, the d-axis current value Id _1det + Id _2det + Id _3det +... Id _Ndet obtained by adding the d-axis coordinate conversion result is stored in the memory.

(6) q-axis current detector (Iq_det (N times))
Among the results D, the q-axis current value Iq _1det + Iq _2det + Iq _3det +... Iq _Ndet obtained by adding the q-axis coordinate conversion results is stored in the memory.

(7) Averaging processing unit (5) Id _1det + Id _2det + Id _3det +... Id _Ndet stored in the d-axis current detection unit is divided by the number of samples N (ΣId _{1det to Ndet} ) / N = Id _avedet
Is calculated and stored in the memory as an N-time average Id _avedet .

Further, (6) Iq _1det + Iq _2det + Iq _3det +... Iq _Ndet stored in the q-axis current detector is divided by the number of samples N (ΣIq _{1det to Ndet} ) / N = Iq _avedet
Is calculated and stored in the memory as an addition average Iq _avedet for N times.

(8) Current detector (I1det)
(7) (Idavedet ² + Iqavedet ² ) ^1/2 = I1det (current detection effective value) is calculated from the addition average Id _avedet and Iq _avedet stored in the averaging processing unit and stored in the memory .

  In FIG. 2, the command block includes the following sections (9) to (21).

(9) Torque command output unit A torque command τref based on a request torque given from the host device or from the outside is output to (11) a current command table and (12) a phase command table described later.

(10) Rotational speed calculation unit (v)
The rotation speed v of the motor 52 calculated from the output signal θdet of the resolver (magnetic pole position sensor 55 shown in FIG. 1) that detects the rotation angle (magnetic pole phase) of the motor 52 is described in (11) current command table (12) ) Output to the phase command table.

(11) Current command table (9) d-axis current (flux current) command flowing in the armature winding of the motor 52 corresponding to the torque command τref and the rotational speed v of the torque command output unit and (10) rotational speed calculation unit A current command table storing Id1ref and q-axis current (torque current) command Iq1ref is provided.

(13) Current command output unit (I1ref)
With reference to the (11) current command table, the current command is selected from the d-axis current command Id1ref and the q-axis current command Iq1ref selected (corresponding to) (9) the torque command τref and (10) the rotational speed v. The effective value I1ref = (Id1ref ² + Iq1ref ² ) ^1/2 is calculated and output.

  Here, the d-axis current Id is a current component in phase with the voltage induced in the armature winding, and the q-axis current Iq is a current component orthogonal to the voltage induced in the armature winding.

(12) Phase command table The (9) torque command τref and (10) the d-axis current command Id1ref and the q-axis current command Iq1ref flowing in the armature winding of the motor 52 are obtained from the rotational speed v, and the current phase command φref is d Formula (1) from the ratio of the shaft current command Id1ref and the q-axis current command Iq1ref
φref = tan ⁻¹ (Iq1ref / Id1ref) (1)
And (9) a phase command table in which a current phase command φref corresponding to the rotational speed v is stored.

(14) Current phase command output section (φref)
With reference to the (12) phase command table, the current phase command φref selected from the d-axis current command Id1ref and the q-axis current command Iq1ref, that is, corresponding to the torque command τref and the rotational speed v is output.

(15) PI (proportional integral) control unit (13) Subtracter for deviation between current command effective value I1ref output from current command output unit and (8) current detection effective value I1det calculated by current detection unit 61, the deviation is input to a proportional / integral calculation controller (PI controller), and a voltage command V1_ref is obtained by the proportional / integral calculation.

(16) Voltage command output unit (V1ref)
(15) The voltage command V1_ref = (Vd_ref ² + Vq_ref ² ) ^1/2 obtained by the PI control unit is output.

(17) Voltage correction calculation unit for synchronous PWM (18) In the synchronous PWM generation circuit to be described later, the Fourier equation is expanded from the voltage command V1ref of (16) and synchronized so that the current fundamental wave component becomes continuous by current control. Calculate the pulse each time. However, since harmonic components increase in the overmodulation region, the difference between the manipulated variable (the value to be controlled) and the true value (the value that should be controlled originally) affects the detection.

  Therefore, (17) the synchronous PWM voltage correction calculation unit stores the correction operation amount α obtained by FFT analysis for the waveform rate determined by the number of synchronous pulses and the pulse width, and the multiplier 62 outputs (16) voltage command output. The corrected voltage command V1ref ′ obtained by multiplying the voltage command V1ref from the unit by the correction operation amount α is output to the (18) synchronous PWM generation circuit.

(18) Synchronous PWM generation circuit (16) Voltage command V1ref ′ obtained by multiplying the voltage command V1ref by (17) the correction operation amount α calculated by the synchronous PWM voltage correction calculation unit, and (14) current phase Based on the current phase command φref from the command output unit, three-phase voltage commands Vu ^* , Vv ^* , Vw ^* are generated.

  In order to make the current fundamental wave component continuous (to establish torque continuity with the fundamental wave component), the pulse train is created after the number of synchronous pulses is determined in advance (for example, 3 pulses) and the corrected voltage command A Fourier series expansion formula based on V1ref ′ is calculated on the S / W (CPU software) side each time to obtain a pulse train phase β (β indicates a resolver magnetic pole phase based on θdet).

  The fundamental wave equation in the case of 3 pulses can be expressed by equation (2).

V = (4 / π) {cos β−cos 30 ° + cos (60 ° −β)} (2)
In this case, the UVW phase voltage command V1ref ′ is given by
First pulse rising phase: β °
First pulse falling phase: 30 °
Second pulse rising phase: 60-β °
Second pulse falling phase: 180 + β °
Third pulse rising phase: 210 °
Third pulse falling phase: 210 + β °
It becomes.

  Here, FIG. 3 shows an example of a pulse train generated by the (18) synchronous PWM generation circuit. FIG. 3 shows the U-phase, V-phase, and W-phase pulse trains when the pulse train phase β is 30 °, and the signals between the U-V phase, the V-W phase, and the W-U phase.

  In the U phase, the first pulse train rises at 0 °, falls at 30 °, the second pulse train rises at 60 °, falls at 180 °, the third pulse train rises at 210 °, and rises at 240 ° Is going down.

  This relationship is the same for the V-phase and the W-phase, and the three-phase pulse train is bilaterally symmetric (ensuring symmetry) at 120 °.

As described above, the pulse train phase β of each phase is obtained from the voltage command V1ref ′ and the number of synchronization pulses, the rising phase and the falling phase of each pulse train are determined, and the pulse train information obtained by offsetting the current phase command φref to each phase is obtained in three phases. Output as phase voltage commands Vu ^* , Vv ^* , Vw ^* .

(19) U-phase PWM command output unit The U-phase voltage command Vu ^* generated by the (18) synchronous PWM generation circuit is output to a gate drive circuit (not shown).

(20) V-phase PWM command output unit (18) The V-phase voltage command Vv ^* generated by the synchronous PWM generation circuit is output to a gate drive circuit (not shown).

(21) W-phase PWM command output unit (18) The W-phase voltage command Vw ^* generated by the synchronous PWM generation circuit is output to a gate drive circuit (not shown).

In a gate drive circuit (not shown), the motor control is performed by outputting a gate signal based on the input three-phase voltage commands Vu ^* , Vv ^* , Vw ^* to the inverter 50a to control the on / off of the switching element. Is going.

  The control unit 50b including the units (1) to (21) in FIG. 2 is configured by, for example, a computer, and hardware resources of a normal computer such as a ROM, a RAM, a CPU, an input device, an output device, and a communication interface. , A hard disk, a recording medium, and a driving device thereof. As a result of cooperation between the hardware and software resources (OS, application, etc.), the control unit 50b implements the units (1) to (21) in FIG.

  (1) U-phase current detector, (2) V-phase current detector, (3) magnetic pole phase detector, (4) 3-phase / 2-phase converter, (5) d-axis current detector, 6) The q-axis current detection unit, (7) the averaging processing unit, and (8) the current detection unit constitute current detection effective value calculation means of the present invention.

  The (9) torque command output unit, (10) rotation speed calculation unit, (11) current command table, and (13) current command output unit of FIG. 2 constitute the current command effective value calculation means of the present invention.

  The (9) torque command output unit, (10) rotational speed calculation unit, (12) phase command table, and (14) current phase command output unit of FIG. 2 constitute the current phase command output means of the present invention.

  The subtractor 61, (15) PI control unit, and (16) voltage command output unit of FIG. 2 constitute voltage command generation means of the present invention.

  The synchronous PWM voltage correction calculation section and multiplier 62 in FIG. 2 constitute the synchronous pulse width modulation voltage correction means of the present invention.

  The synchronous pulse width modulation signal generation means of the present invention is constituted by the (18) synchronous PWM generation circuit of FIG.

  Next, the operation and operation of the motor control device configured as described above will be described.

  In the current control synchronized with the carrier frequency in the sine wave PWM control, as shown in FIG. 6 showing the timing of the current detection and the current control in the sine wave PWM control, the upper vertex (top) and the lower vertex (bottom) of the carrier are obtained. Zero vectors (1.1.1) and (0.0.0) are always generated, and current detection and current control are simultaneously performed at the upper vertex (top) and the lower vertex (bottom) of this carrier. By performing current detection at points of zero vectors (1.1.1) and (0.0.0) without such current fluctuation, control with a small detection error was possible.

  The three-phase voltage vectors (U, V, W) are (1.0.0), (0.1.0), (0.0) when 1 is ON and 0 is OFF in the PWM switching pattern. 0.1), (0.1.1), (1.0.1), (1.1.0), (0.0.0), (1.1.1).

  However, in the case of overmodulation control by synchronous PWM (PWM control in which the fundamental wave and the carrier are synchronized), since the voltage control rate is in the overmodulation region, there is no zero vector in one cycle, and current detection during current change Current detection with different current waveform rates, such as harmonics, and detection errors with respect to fundamental wave components increase.

  Therefore, in the present invention, as described above, in the case of overmodulation control using synchronous PWM, a detection error becomes large, so that current detection based on instantaneous current cannot be used for current control, and therefore 60 ° periodicity is applied to three-phase alternating current. Focusing on the fact that there is, there is a current detection method.

Even in an alternating current including harmonics, the current waveform has periodicity every 60 ° period. Therefore, in FIG. 2 (1) to (7) by each part of average discretized sample number N times in the range of microcomputer processable resolution by the multi-point samples were three-phase / two-phase conversion current Id _{Avedet, Obtain} Iq _avedet .

  For example, the current is detected N times within a 60 ° periodicity, and if N = 4 times, the current is detected every 15 °.

  Such current detection can suppress detection errors even during current change and current control including harmonics. In addition, the voltage command is calculated by the (17) synchronous PWM voltage correction calculation unit and multiplier 62. By correcting the above, it is possible to perform control while suppressing an error between the operation amount (value to be controlled) and the true value (value that should originally be controlled).

  4A and 4B are diagrams showing current waveforms and timings of current detection and current control. FIG. 4A shows a case where the current detection and current control timing are the same, and FIG. 4B shows current detection as in the present invention. And the case where the current control is performed at the timing after the three-phase / 2-phase conversion is performed at multiple points is shown.

  As described above, since the prior art such as Patent Document 1 in the detection stage detects the instantaneous current by filtering, the deviation from the actual detected current value is large and there is no control periodicity. However, in the multipoint average current detection method according to the present embodiment, the detection accuracy can be increased as long as it is within a detectable resolution (N times), and current control with 60 ° periodicity can be maintained. Therefore, more stable current control than the prior art can be constructed.

  Further, since the prior art such as Patent Document 1 in the command stage uses general dq axis current control, it is necessary to move the control of two lines as processing. However, in the present embodiment, the phase (φ) is previously mapped in the (12) phase command table, so that the current information is (8) the deviation between the output of the current detection unit and (13) the output of the current command output unit. As a result, the processing was simplified and the processing speed was improved.

(5) ... d-axis current detector (6) ... q-axis current detector (7) ... averaging processor (11) ... current command table (12) ... phase command table (13) ... current command output unit (14 ) ... Current phase command output unit (15) ... PI control unit (16) ... Voltage command output unit (17) ... Synchronous PWM voltage correction calculation unit (18) ... Synchronous PWM generation circuit 50 ... Motor control device 50a ... Inverter 50b ... Control unit 51 ... Storage battery 52 ... Motor 53 ... DC voltage detection sensor 54a to 54c ... AC current detection sensor 55 ... Magnetic pole position sensor 61 ... Subtractor 62 ... Multiplier

Claims (6)

A control device for a rotating machine that controls an applied voltage of the rotating machine by an inverter that converts a DC voltage into an AC voltage,
At the time of overmodulation control by synchronous pulse width modulation, in synchronization with a set number of magnetic pole phase values obtained by detecting the magnetic pole position of the rotating machine for each set period, the three-phase AC current of the inverter is detected a set number of times, The detected number of set three-phase AC current values are converted into three-phase / two-phase coordinates based on the set number of magnetic pole phase values to obtain a set number of d-axis current values and a set number of q-axis current values. Point current sample acquisition means;
Current detection effective value calculation means for calculating an addition average value of the obtained set number of d-axis current values and a set number of q-axis current values and calculating a current detection effective value from each of the addition average values; ,
Current command effective value calculation means for calculating a current command effective value based on the requested torque command and the rotation speed of the rotating machine calculated from the magnetic pole phase value obtained by detecting the magnetic pole position of the rotating machine;
Current phase command output means for outputting a current phase command corresponding to the torque command and the rotational speed of the rotating machine;
The deviation between the current detection effective value calculated by the current detection effective value calculation means and the current command effective value calculated by the current command effective value calculation means is subjected to PI (proportional integration) control to obtain the deviation. Voltage command generation means for generating a voltage command according to
A pulse series phase is obtained by calculating a Fourier series expansion formula based on the voltage command generated by the voltage command generating means, a width of the pulse train is calculated from the voltage command and the set number of synchronous pulses, and the width of the pulse train and the pulse train From the phase, the rising phase and the falling phase of the three-phase pulse train are determined, and based on the pulse train information and the current phase command output from the current phase command output means, the three-phase phase voltage command Vu ^* , Synchronization pulse width modulation signal generating means for generating Vv ^* and Vw ^* ,
A rotating machine control device characterized in that the switching element of the inverter is controlled to be turned on / off by three-phase phase voltage commands Vu ^* , Vv ^* , Vw ^* generated by the synchronous pulse width modulation signal generating means.   The voltage command generated according to the voltage command generation means is multiplied by the waveform rate determined by the number of synchronization pulses and the pulse width obtained by FFT (Fast Fourier Transform) analysis as a correction manipulated variable, 2. The control apparatus for a rotating machine according to claim 1, further comprising a voltage correction means for synchronizing pulse width modulation that generates a voltage command and outputs the voltage command to the synchronizing pulse width modulation signal generating means. The current phase command output means converts the current phase command calculated from the ratio of the d-axis current command and the q-axis current command obtained from the torque command and the rotational speed of the rotating machine into the torque command and the rotating speed of the rotating machine. Correspondingly stored phase command table,
3. The rotating machine control device according to claim 1, wherein a current phase command corresponding to a torque command and a rotation speed of the rotating machine is output with reference to the phase command table. 4. A control method for a rotating machine that controls an applied voltage of a rotating machine by an inverter that converts a DC voltage into an AC voltage,
The multi-point current sample acquisition means synchronizes with the set number of magnetic pole phase values obtained by detecting the magnetic pole position of the rotating machine for each set period during overmodulation control by synchronous pulse width modulation, A set number of d-axis current values and a set number are detected by detecting the set number of AC currents and converting the three-phase AC current value of the set number of detected times to three-phase / two-phase coordinates based on the set number of magnetic pole phase values. A multi-point current sample acquisition step for obtaining a q-axis current value of
The current detection effective value calculation means obtains the addition average value of the obtained set number of d-axis current values and the addition average value of the set number of q-axis current values, and calculates the current detection effective value from each of the addition average values. Current detection effective value calculation step to perform,
The current command effective value calculation means calculates the current command effective value based on the requested torque command and the rotation speed of the rotating machine calculated from the magnetic pole phase value obtained by detecting the magnetic pole position of the rotating machine. A value calculation step;
A current phase command output step, wherein the current phase command output means outputs a current phase command corresponding to the torque command and the rotational speed of the rotating machine;
The voltage command generating means is PI (proportional integral) with respect to a deviation between the current detection effective value calculated by the current detection effective value calculation means and the current command effective value calculated by the current command effective value calculation means. A voltage command generation step for generating a voltage command according to the deviation by performing control;
Synchronous pulse width modulation signal generating means calculates a pulse train phase by calculating a Fourier series expansion formula based on the voltage command generated by the voltage command generating means, and calculates the width of the pulse train from the voltage command and the set number of synchronous pulses. Then, the rising phase and falling phase of the pulse train of each of the three phases are determined from the width of the pulse train and the pulse train phase, and based on the pulse train information and the current phase command output from the current phase command output means, A synchronous pulse width modulation signal generation step for generating three phase voltage commands Vu ^* , Vv ^* , Vw ^* ,
A control method for a rotating machine, wherein the switching elements of the inverter are controlled to be turned on / off by three-phase phase voltage commands Vu ^* , Vv ^* , Vw ^* generated in the synchronous pulse width modulation signal generation step.   The voltage correction means for synchronizing pulse width modulation multiplies the voltage command generated by the voltage command generating means by the waveform rate determined by the number of synchronizing pulses and the pulse width obtained by FFT analysis as a correction operation amount. 5. The method for controlling a rotating machine according to claim 4, further comprising: a synchronous pulse width modulation voltage correcting step for generating a corrected voltage command and outputting the generated voltage command to the synchronous pulse width modulation signal generating means.   In the current phase command output step, the current phase command calculated from the ratio of the d-axis current command and the q-axis current command obtained from the torque command and the rotational speed of the rotating machine is converted into the torque command and the rotating speed of the rotating machine. 6. The method for controlling a rotating machine according to claim 4, wherein a torque command and a current phase command corresponding to the rotational speed of the rotating machine are output with reference to the corresponding stored phase command table.

Images