JP2013031361A - DC brushless motor - Google Patents

Abstract

An AC input DC brushless motor capable of directly inputting an AC power source such as a commercial AC power source and capable of being driven at a speed corresponding to the frequency of the commercial power source.
An AC input DC brushless motor according to the present invention includes a motor unit having at least a driving winding and a mover, a power element for supplying driving power to the driving winding, and a power control unit for controlling the driving power. A speed control unit that generates a speed control signal, a terminal unit to which commercial AC power is input, and a stabilization unit that stabilizes the frequency of the commercial AC power input. The speed control unit outputs the speed control signal to the power control unit based on the frequency of the commercial AC power input to the terminal unit, and controls the motor unit, power element, power control unit, and speed control. And is driven at a speed corresponding to a commercial power frequency by connecting a commercial AC power source to the terminal unit.
[Selection] Figure 1

Description

  The present invention relates to an AC input DC brushless motor that is mainly used in home appliances such as air conditioners and is driven by directly inputting commercial AC power.

  As a motor that can be directly driven by a commercial AC power supply, an induction motor is well known as disclosed in Patent Document 1, and has been used for a rotating mechanism such as a fan of an air conditioner.

  However, induction motors have a problem in terms of efficiency because they need to be excited to a secondary conductor in principle, and replacement with DC brushless motors is advancing due to the recent increase in efficiency of equipment and demand for power saving. is there. And this trend is getting stronger with increasing global environmental awareness.

  In order to replace the DC brushless motor with an induction motor, it is necessary to provide a DC power source for driving, a speed control function for realizing a rotational speed accuracy performance equivalent to that of the induction motor, and the like.

  In particular, in order to realize a DC brushless motor having a speed control function, a method using a crystal oscillator as a speed cycle reference signal as in Patent Document 2 is generally known. Moreover, an example of a DC motor (motor with a DC brush) whose speed is controlled based on the frequency of a commercial AC power source as disclosed in Patent Document 3 is disclosed. These disclosed technologies require that a DC power source for driving the motor needs to be prepared outside the motor. In particular, in the technology of Patent Document 3, if the frequency of the commercial AC power source changes, a DC motor There is a problem that the number of rotations changes.

  An example of speed control of a DC brushless motor will be specifically described with reference to FIGS.

  FIG. 8 is a configuration example of a conventional DC brushless motor, which includes a motor unit 4 including a stator 3 having a driving winding and a mover 2, and a plurality of power elements 5 a to 5 that supply driving power to the stator 3. A power unit 6 comprising 5f, a power control unit 7 for controlling the driving power of the power unit 6, a position signal generating unit 8 for generating a signal corresponding to the position of the mover 2, and a rotational speed of the mover 2 are controlled. A speed control unit 9 that generates a speed control signal to be transmitted, and a terminal unit 10 to which a DC power supply unit 17 is input.

  The power control unit 7 receives the mover position signal generated by the position signal generation unit 8 and the speed control signal output from the speed control unit 9, and turns on / off the plurality of power elements 5a to 5f according to the mover position signal. The mover 2 is driven by control, and the energization amount of the plurality of power elements 5a to 5f is controlled by the speed control signal to accelerate and decelerate the rotation speed of the mover 2.

  The speed controller 9 outputs the actual rotation output from the rotation speed detector 14 based on the speed reference signal that is a frequency-divided signal of the crystal oscillator output unit 16 and the mover position signal output from the position signal generator 8. The number signal is compared by the comparison unit 13 and a speed control signal is output from the control amplifier unit 15 to the power control unit 7 according to the comparison result.

  FIG. 9 shows the operation of the speed controller of the conventional DC brushless motor.

  A speed reference signal output by frequency division from the crystal oscillator output unit 16 and an actual rotational speed signal output from the rotational speed detection unit 14 based on the mover position signal output from the position signal generator 8 Are compared by the comparison unit 13. The output of the comparison unit 13 is transmitted to the power control unit 7 through the control amplifier unit 15 as an acceleration / deceleration command. The power control unit 7 controls the energization amounts of the plurality of power elements 5 a to 5 f of the power unit 6 according to the acceleration / deceleration command of the control amplifier unit 15. As a result, the voltage or current applied to the stator 3 is controlled, and the mover 2 can be moved at a desired rotational speed.

  In section B of FIG. 9, since the period t2 of the actual rotation speed signal output from the rotation speed detection section 14 is longer than the period t0 of the speed reference signal output from the crystal oscillator output section 16, the comparison section 13 determines that the rotation speed is slow. Then, an “H” level signal is output, and an acceleration speed control signal is output from the control amplifier unit 15 to the power control unit 7. As a result, the power control unit 7 operates to increase the energization amount of the power unit 6 and increase the rotational speed. In section C, since the period t3 of the actual rotational speed signal is short, the comparison unit 13 determines that the rotational speed is fast and outputs an “L” level signal, and sends a deceleration speed control signal from the control amplifier unit 15 to the power control unit. 7 is output. As a result, the power control unit 7 operates so as to decrease the energization amount of the power unit 6 and reduce the rotational speed. In this way, the speed control is performed so that the speed cycle reference signal and the actual rotation speed cycle substantially coincide. Approximate coincidence means that acceleration and deceleration commands are repeated and controlled so that the difference between the speed reference signal and the actual rotation speed signal converges to zero. This means that the deceleration is stabilized so as to reach a desired rotational speed by repeating the command. The section A shows a state where the period t0 of the speed reference signal and the period t1 of the actual rotational speed signal completely coincide with each other, but the state of the section A maintaining the state where there is no acceleration / deceleration command is actually Will not happen.

JP 58-54335 A JP-A-1-164287 JP 59-52228 A

  However, since the above conventional method is based on the assumption of a DC power supply input, it is not configured to be compatible with an AC power input such as a commercial AC power supply, and a crystal oscillator is used as a speed control reference signal. It is expensive to realize a DC brushless motor as a replacement for an AC induction motor used in home appliances. In addition, when there is a voltage fluctuation or frequency fluctuation of the power supply due to deterioration of the power supply situation or the like, there is a problem that the rotation speed fluctuation of the motor accompanying this affects the performance such as the operation and efficiency of the device.

  The present invention solves the above-described conventional problems, and provides an AC input DC brushless motor that can directly input an AC power source such as a commercial AC power source and can be driven at a speed corresponding to the frequency of the commercial power source. Is. In other words, an AC input DC brushless motor that can be directly connected to a commercial AC power source and inherits the convenience of an induction motor driven at a rotational speed corresponding to the frequency is provided.

  In addition, even if there is a voltage fluctuation or frequency fluctuation of the commercial power supply due to deterioration of the power supply situation, etc., an AC input DC brushless motor that suppresses fluctuations in the rotational speed and does not affect the operation and performance of the device on which the motor is mounted. Is to provide.

  An AC input DC brushless motor of the present invention includes a brushless motor unit having at least a single-phase or multiple-phase drive winding and a mover, a plurality of power elements that supply drive power to the drive winding, and the plurality A power control unit that controls the driving power of the power element, a position signal generation unit that generates a mover position signal corresponding to the position of the mover, and a speed control unit that generates a speed control signal of the mover, And a terminal unit to which a commercial AC power is input, and the power control unit includes the plurality of power elements that receive the mover position signal and the speed control signal and perform on / off control according to the mover position signal. The power element is selected from the power elements to drive the mover, and the energization amount of the plurality of power elements is controlled by the speed control signal, and the speed control unit includes the terminal A speed unit that controls a speed of the mover based on a frequency information signal that is reduced or ignored by the stabilization unit. A control signal is output to the power control unit, and includes at least the brushless motor unit, the plurality of power elements, the power control unit, the position signal generation unit, and the speed control unit, It is configured to be driven at a speed corresponding to the frequency of the commercial power supply by connecting the commercial AC power supply to the terminal section, and the speed is not affected by the frequency fluctuation of the commercial AC power supply by the stabilizing section.

  As a result, even if there are voltage fluctuations or frequency fluctuations in the commercial power supply due to deterioration of power supply conditions, etc., AC input DC brushless that suppresses fluctuations in the rotational speed and does not affect the operation and performance of the device on which the motor is mounted. A motor can be realized.

  The AC input DC brushless motor of the present invention can be directly connected to a commercial AC power source, and realizes the convenience of the induction motor that is driven at the number of rotations according to the power frequency and the high efficiency performance of the DC brushless motor at low cost. can do. In addition, even when there is a voltage fluctuation or frequency fluctuation of the commercial power supply due to deterioration of the power supply situation, there is an effect that the rotation speed fluctuation is suppressed and the operation and performance of the device on which the motor is mounted is not affected. Then, in applications such as home appliances where induction motors have been mainly used so far, replacement with higher-efficiency DC brushless motors can be promoted, and the energy-saving performance of devices equipped with these motors can be improved.

The figure which showed the structure of Embodiment 1 of this invention The figure explaining operation | movement of Embodiment 1 of this invention The figure explaining operation | movement of Embodiment 1 of this invention The figure explaining operation | movement of Embodiment 2 of this invention The figure explaining operation | movement of Embodiment 3 of this invention Figure of example of position signal generator using Hall element of the present invention Diagram of an example of a position signal generator using the shunt resistor of the present invention The figure which showed the structural example of the conventional DC brushless motor The figure explaining operation in the example of composition of the conventional DC brushless motor

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

(Embodiment 1)
FIG. 1 is a diagram showing the configuration of an AC input DC brushless motor common to all the embodiments of the present invention, FIG. 2 shows the operation common to all, and FIG. 3 shows the stabilization unit 23 in the first embodiment. It is the figure shown about the operation | movement.

  A DC brushless motor with an AC input according to the first embodiment shown in FIG. 1 includes a stator 3 having drive windings, a motor unit 4 having a mover 2, and power elements such as a plurality of MOSFETs for supplying driving power to the stator 3. The power unit 6 composed of 5a to 5f, the power element 5a, the power element 5b, the power element 5c, the power element 5d, the power element 5e, the power control unit 7 for controlling the driving power of the power element 5f, and the position of the mover 2 A position signal generating unit 8 that generates a mover position signal according to the speed, a speed control unit 9 that generates a speed control signal for the mover 2, a terminal unit 10 to which the commercial AC power source 1 is input, and a commercial AC power source 1 And an AC / DC conversion unit 11 that converts the voltage into a DC voltage.

  The power control unit 7 receives the mover position signal and the speed control signal, selects a power element for on / off control from the plurality of power elements 5a to 5f based on the mover position signal, and energizes the mover position signal. 2 is driven, and the energization amount of the power element is controlled by the speed control signal.

  The speed control unit 9 includes a stabilization unit 23 that reduces or ignores frequency fluctuations of the commercial AC power supply 1 input to the terminal unit 10. The speed control unit 9 converts the frequency fluctuation signal into frequency information signals that have been reduced or ignored by the stabilization unit 23. Based on this, a speed control signal for controlling the speed of the mover 2 is output to the power control unit 7.

  Here, the motor unit 4, the power unit 6 including a plurality of power elements 5 a to 5 f, the power control unit 7, the position signal generation unit 8, the speed control unit 9, the terminal unit 10, and the AC / DC conversion unit 11. And an AC input DC brushless motor that is driven at a speed corresponding to the frequency of the commercial power source by connecting the commercial AC power source 1 to the terminal unit 10. Note that the AC / DC converter may or may not have a smoothing capacitor.

  FIG. 2 shows the operation of the speed control unit 9 excluding the stabilization unit 23, particularly regarding the common operation of the speed control of the above-described AC input DC brushless motor.

  The frequency detection unit 12 takes in the power supply frequency of the commercial AC power supply 1, inputs it to the stabilization unit 23, and outputs the frequency output from the stabilization unit 23 as a speed reference signal. The rotation speed detector 14 processes the mover position signal corresponding to the position of the mover 2 output from the position signal generator 8 and outputs the cycle as an actual rotation speed signal. The speed reference signal and the actual rotational speed signal are compared by the comparison unit 13. The output of the comparison unit 13 is subjected to processing such as phase compensation for amplification and control stabilization by the control amplifier unit 15, and is transmitted to the power control unit 7 as an acceleration command or a deceleration command. The power control unit 7 controls the energization amount of the plurality of power elements 5 a to 5 f of the power unit 6 by the output from the control amplifier unit 15, and controls the applied voltage or current of the stator 3 to drive the mover 2. .

  In the section B of FIG. 2, the period t0 of the speed reference signal output from the stabilization unit 23 and the period t2 of the actual rotation speed signal output from the rotation speed detection unit 14 are compared. Since t2 is longer, the comparison unit 13 determines that the rotational speed of the motor is slow, and outputs an “H” level signal. As a result, the control amplifier unit 15 outputs an acceleration command. In section C, the period t3 of the actual rotational speed signal is short, and the comparison unit 13 determines that the rotational speed of the motor is fast and outputs an “L” level signal. As a result, the control amplifier unit 15 outputs a deceleration command. In this way, the cycle of the speed reference signal corresponding to the frequency of the commercial AC power supply 1 is movable so that the cycle of the actual rotational speed signal output from the rotational speed detector based on the mover position signal is substantially the same. The speed of the child is controlled. Approximate coincidence means that acceleration and deceleration commands are repeated and controlled so that the difference between the speed reference signal and the actual rotation speed signal converges to zero. This means that the deceleration is stabilized so as to reach a desired rotational speed by repeating the command. The section A shows a state in which the period of the speed reference signal and the period of the actual rotational speed signal completely coincide with each other. However, the state of the section A that maintains the state in which there is no acceleration / deceleration command actually occurs. Absent.

  Hereinafter, the operation of the stabilization unit 23 according to the first embodiment will be described with reference to FIG.

  The stabilization part 23 extracts the average frequency of A, B, and C section of the commercial alternating current power supply 1 as a frequency information signal, and controls a motor by using this as a speed reference signal. Thus, by using the average frequency of the commercial AC power supply as the speed reference signal, fluctuations in the rotational speed of the motor can be suppressed and stabilized with respect to frequency fluctuations in the commercial AC power supply.

  In addition, although the frequency | count of averaging was made into 3 times in the example of FIG. 3, it is not this limitation.

(Embodiment 2)
FIG. 4 shows the operation of the second embodiment having the stabilization unit 23. This will be described below.

  In FIG. 4, when the frequency of the commercial AC power supply 1 is A, B, and C intervals and the same period t1 is extracted three times in succession, the stabilization unit 23 sets this as the frequency information signal of the commercial AC power supply 1. The output information is updated to the newly extracted cycle t1 from the cycle t0 until. Further, when the frequency of the commercial AC power supply 1 is temporarily different from the frequency of the previous cycle as in the D section, the output is not updated as the frequency information signal, and the operation is performed to maintain t1. As a result, it is possible to prevent fluctuations in the motor rotation speed when the commercial AC power supply fluctuates instantaneously, and it becomes possible to drive stably at a desired rotation speed.

(Embodiment 3)
FIG. 5 shows the operation of the third embodiment having the stabilization unit 23. This will be described below.

  In FIG. 5, the stabilization unit 23 samples the frequency of the commercial AC power supply 1 three times in the A, B, and C sections, and outputs majority information t1 of the sampled frequency as a frequency information signal. The majority information of the sampled frequency is used as a frequency information signal, and this is used as a speed reference signal, so that even when an abnormal frequency is erroneously detected due to noise or the like, the frequency of the commercial AC power supply 1 can be accurately measured, and desired stable The motor can be driven at the rotation speed. (In addition, it describes about the free number of a code number. There is no component which points to the code | symbol 22 and it is a free number.)

  As described above, the DC brushless motor of AC input shown in the first to third embodiments includes the stabilization unit 23, so that even when the commercial AC power supply becomes unstable due to deterioration of the power supply situation, It has the effect of stabilizing the rotational speed, and can prevent the deterioration of the performance of equipment equipped with a motor.

  6 and 7 are specific examples of the position signal generator 8 that generates a signal corresponding to the position of the mover 2. FIG. 6 shows an example in which the Hall element 18 is used, and FIG. This is an example used for position sensorless driving. In addition, as shown in FIG. 6, it is the structure provided with the comparator 19. As shown in FIG. Also, as shown in FIG. 7 and FIG.

  As described above, the AC input DC brushless motor of the present invention can be directly connected to a commercial AC power supply and is driven at a rotational speed corresponding to the power supply frequency, and the high efficiency performance of the DC brushless motor. Can be realized at low cost. In addition, there is an effect that an AC input DC brushless motor that can be driven at a stable rotational speed even in a region where the frequency of the commercial power source is different and does not impair the efficiency performance of the device can be realized. Furthermore, even when there are voltage fluctuations and frequency fluctuations of the commercial power supply due to the deterioration of the power supply situation, there is an effect that the rotation speed fluctuation is suppressed and the operation and performance of the device on which the motor is mounted are not affected.

  In addition, although it described as a DC brushless motor above, according to another name, it may be described as a DC brushless motor. Similarly, although described as AC input, according to another name, it may be described as AC input.

  The AC input DC brushless motor of the present invention can be used for home appliances such as air conditioners in which induction motors have been mainly used so far, and in these devices, replacement with higher efficiency DC brushless motors is promoted. And it can contribute to the improvement of the energy-saving performance of equipment equipped with these motors.

DESCRIPTION OF SYMBOLS 1 Commercial AC power supply 2 Movable element 3 Stator 4 Motor part 5a, 5b, 5c, 5d, 5e, 5f Power element 6 Power part 7 Power control part 8 Position signal generation part 9 Speed control part 10 Terminal part 11 AC / DC conversion Section 12 Frequency detection section 13 Comparison section 14 Rotation speed detection section 15 Control amplifier section 16 Crystal oscillator output section 17 DC power supply section 18 Hall element 19 Comparator 20 Shunt resistor 21 OP amplifier 23 Stabilization section

Claims (4)

A motor unit having at least a single-phase or multiple-phase driving winding and a mover, a plurality of power elements for supplying driving power to the driving winding, and power control for controlling the driving power of the plurality of power elements A position signal generating unit that generates a mover position signal corresponding to the position of the mover, a speed control unit that generates a speed control signal of the mover, and a terminal unit to which commercial AC power is input. Prepared,
The power control unit receives the mover position signal and the speed control signal, selects a power element that performs on / off control based on the mover position signal from the plurality of power elements, and drives the mover. , Controlling the energization amount of the plurality of power elements by the speed control signal,
The speed control unit includes a stabilization unit that reduces or ignores frequency fluctuations of the commercial AC power input to the terminal unit, and the speed control unit is based on the frequency information signal whose fluctuations are reduced or ignored by the stabilization unit. The speed control signal for controlling the speed of the mover is output to the power control unit,
The motor unit, the plurality of power elements, the power control unit, the position signal generation unit, and the speed control unit are built in at least, and the frequency of the commercial power supply is connected by connecting the commercial AC power source to the terminal unit. An AC input DC brushless motor configured to be driven at a speed corresponding to the speed and not affected by the frequency fluctuation of the commercial AC power supply by the stabilizing unit. The DC brushless motor according to claim 1, wherein the stabilization unit outputs an average frequency of the commercial AC power supply as a frequency information signal. When the frequency of the commercial AC power supply is the same for a plurality of times, the stabilization unit updates the output as the frequency information signal using the frequency of the commercial AC power supply, and the frequency of the commercial AC power supply is at least one cycle before the frequency. The DC brushless motor according to claim 1, wherein the output is not updated as a frequency information signal when the frequency information signal is different. 2. The DC brushless motor according to claim 1, wherein the stabilization unit samples the frequency of the commercial AC power source three times or more and outputs majority information of the sampled frequency as a frequency information signal.

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