JP2002095281A - Brushless motor drive controller, washing machine and compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem of insufficient performance of a load pulsation suppressing capability due to a rough control because a voltage pattern applied to a brushless motor by dividing one revolution into twelve sections is corrected when a conventional brushless motor drive controller uses a brushless motor of a 3-phase 4-pole type. SOLUTION: When the brushless of the 3-phase 4-pole type is used, one revolution of the motor is divided into twelve sections to obtain rotation signals, the signals are linearly interpolated between adjacent signals, the interpolated signals are further N-divided, and armature windings are drive controlled by applied voltages corresponding to rotating speeds of the N-divided sections.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to control of a brushless motor used for a motor of an air conditioner, a compressor of a refrigerator, a washing machine, and the like, and more particularly to a brushless motor drive control device for canceling load pulsation. Things.

[0002]

2. Description of the Related Art FIG.
1 is a configuration diagram showing a conventional brushless motor drive control device as disclosed in Japanese Patent Publication No. 386. 13, a brushless motor drive control device includes an inverter device 101.
And a brushless motor 102.

In an inverter device 101, an AC power supply 10
3 is converted into a predetermined DC power by an AC / DC converter 104, and the DC power is switched by switching elements Ua, Va, Wa, X, Y, and Z of an inverter 105, and the armature winding of the brushless motor 102 is switched. To supply. The position detection circuit 106 compares the induced voltage waveform (the induced voltage waveform generated in the non-energized phase) included in the terminal voltages of the armature windings U, V, and W of the brushless motor 102 with a reference value. A half point of the induced voltage waveform = a zero cross point of the induced voltage is detected. FIG. 14 is a waveform diagram showing a drive voltage waveform and an induced voltage waveform in each phase coil of the brushless motor 102, and a point indicated by '0' is a zero cross point. The position detection circuit 106 further shapes the waveform of the detected zero-cross point of the induced voltage to generate a position detection signal, which is output to a control circuit 107 mainly composed of a microcomputer. The control circuit 107 switches the switching elements Ua, Va, Wa, X, Y, and Z of the inverter unit 105 via the drive circuit 108 based on the input position detection signal, and switches the U, V, and W armatures of the brushless motor 102. The winding phase is switched.

If the brushless motor 102 has three phases and four poles, a signal obtained by dividing one rotation into twelve is obtained in the control circuit 107, and each section time (a plurality of times) of the obtained twelve divided signal is obtained. Drive circuit 1 so that the average value of the same section time in rotation) converges to the average time of one rotation.
The load pulsation can be canceled by sequentially correcting the voltage pattern applied to the brushless motor 102 via the switch 08.

[0005]

However, in the conventional brushless motor drive control device, one rotation is divided into twelve to correct the voltage pattern applied to the brushless motor, but the speed resolution per rotation is twelve. Therefore, there is a problem that the load pulsation suppressing ability cannot be sufficiently exhibited.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to improve the speed resolution per rotation, sufficiently exhibit a load pulsation suppressing ability, and prevent a decrease in motor efficiency. It is an object of the present invention to provide a brushless motor drive control device that can be used.

[0007]

In a brushless motor drive control device having a brushless motor and an inverter device according to the present invention, the inverter device divides one rotation of the brushless motor into a plurality of sections to obtain a plurality of rotation signals.
This rotation signal is linearly interpolated between adjacent rotation signals, the linearly interpolated rotation signal is further divided into N, and the armature winding is driven by an applied voltage corresponding to the rotation speed of each of the N divided sections. Controlled.

Further, N is a power of two.

Further, the deviation between the rotation signal divided by N and the rotation speed command is repeatedly controlled for each N division section.

Further, the inverter device detects the position of the permanent magnet rotor by using an induced voltage generated in the armature winding.

Further, the brushless motor has a position sensor, and the inverter device detects the position of the permanent magnet rotor based on a signal from the position sensor.

Further, the motor efficiency of the brushless motor does not decrease even in a low load region with respect to the maximum load torque.

A washing machine according to the present invention has a washing tub and the above-described brushless motor drive control device for driving the washing tub.

Further, the compressor according to the present invention has any one of the above-described brushless motor drive control devices.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a configuration diagram showing a brushless motor drive control device according to Embodiment 1 of the present invention. In FIG. 1, the brushless motor drive control device mainly includes an inverter device 1 and a brushless motor 2.

The inverter device 1 supplies the AC power
The DC converter 4 converts the DC power into a predetermined DC power, and this DC power is used as the switching elements Ua, Va, W of the inverter 5.
a, X, Y, Z switching and brushless motor 2
To the armature winding. The position detection circuit 6 compares the induced voltage waveform (the induced voltage waveform generated in the non-energized phase) included in the terminal voltages of the armature windings U, V, and W of the brushless motor 4 with a reference value. A half point of the induced voltage waveform = a zero cross point of the induced voltage is detected. FIG. 2 is a waveform diagram showing a drive voltage waveform and an induced voltage waveform in each phase coil of the brushless motor 102, and a point indicated by '0' is a zero cross point. The position detection circuit 6 further shapes the waveform of the zero-cross point of the detected induced voltage to generate a position detection signal, and the control circuit 7 mainly includes a microcomputer.
Output to The control circuit 7 switches the switching elements Ua, Va, Wa, X, Y, and Z of the inverter unit 105 via the driving circuit 8 based on the input position detection signal, and
The energization phases of the V and W armature windings are switched and driven.

If the brushless motor 2 has three phases and four poles, a signal obtained by dividing one rotation into twelve is obtained.

Normally, in the case of a single rotary compressor, FIG.
As shown in the speed / load torque chart, the load torque Tl applies to the motor a load that pulsates greatly for one rotation. Then, the rotation fluctuation at that time (speed n)
Varies greatly according to the load torque, as also shown in FIG.

On the other hand, the position detection signal sent from the position detection circuit 6 is a signal obtained by dividing one rotation into 12 as described above. When this signal is converted into a rotation signal by the control circuit 7, the speed chart shown in FIG. As shown in the figure, twelve steps of speed fluctuation are obtained. When this control circuit rotation signal is linearly interpolated between adjacent rotation signals in each of 12 steps, a rotation signal as shown in the speed chart of FIG. 5 is obtained, and a rotation signal close to the actual rotation fluctuation is obtained. Therefore, the control circuit 7 linearly interpolates the rotation signal, and further divides the linearly interpolated rotation signal into N portions per one section of the signal divided into 12 to form a speed control loop. FIG. 6 is a diagram showing a configuration of a speed control loop portion in the control circuit 7. In FIG. 6, the rotation signal fr calculated by the subtraction means 70 from the position detection signal is subtracted from the rotation number command fr *, and the signal obtained by the linear interpolation means 71 is subjected to linear interpolation. This linearly interpolated signal is divided into 12 ×
It is divided into n and sent to 12 × n phase shifters 73 connected in parallel. For example, when n is 10, one electric angle period (360 degrees) is divided into 120 and divided into three.
A rotation signal for the degree is sent.

The linearly interpolated signal is also sent to a proportional control gain 74. Thereafter, the outputs of the phase shifter 73 and the proportional control gain 74 are added to the adding means 75
, And is converted into a rotation signal fs *, and is converted into a voltage pattern by f / v conversion means 76. The reason for setting the proportional control gain 74 in parallel with the phase shifter 73 and adding the outputs is to stabilize the speed control loop.
The converted voltage pattern is applied to the brushless motor 2 via the drive circuit 8.

As described above, the rotation signal linearly interpolated is set to 1
Since one section of the signal divided into two is further divided into n to constitute the speed control loop, a fine correction of 12 × n can be performed for one cycle of the electrical angle,
It is possible to obtain a stable rotation that is not affected by the load torque (no fluctuation per rotation = no pulsation).

Here, if n is a power of 2, the processing in the dividing means 72 only needs to be shifted, so that the calculation load on the control circuit 7 is reduced and a higher-performance drive control device can be provided. can do.

Second Embodiment FIG. 7 is a diagram showing a configuration of a speed control loop portion of a control circuit 7 in a brushless motor drive control circuit according to a second embodiment of the present invention. This is to control repeatedly. FIG.
6, the same components as those in FIG. 6 and corresponding components are denoted by the same reference numerals, and description thereof is omitted. In FIG. 7, an adding means 77 and a second phase shifter 78 are connected between the dividing means 72 and each phase shifter 73, and the output from the adding means 77 is shifted in phase by the second phase shifter 78. Addition means 7
At 7, the rotation signal from the dividing means 72 is added. For example, the output from the dividing means 72 and the second
Is added one cycle (360 degrees) earlier by the phase shift 78 by the adder 77, and the resulting rotation signal is shifted by the phase shifter 73 by the phase shift between the fluctuation of the rotation signal and the torque fluctuation (for example, 90 degrees). Degree) shift minutes.

By doing so, the speed control gain can be theoretically set to infinity, and a control device having a higher rotation fluctuation suppressing ability can be realized.

Third Embodiment FIG. 8 is a diagram showing a configuration of a brushless motor control device according to a third embodiment of the present invention. In the brushless motor control drive device of FIG. The magnetic pole is detected and voltage control is performed. In FIG. 8, the same components as those in FIG. 1 and corresponding components are denoted by the same reference numerals.
Description is omitted.

In FIG. 8, a Hall IC 9 serving as a position sensor is shown.
a, 9b, 9c are arranged in each state of the brushless motor 2, detect the magnetic pole position of the magnet, and transmit the result to the position detecting circuit 6. Even in such a configuration, a signal as shown in the Hall signal chart of FIG. 9 is detected, and the position detection circuit 6 can obtain a signal similar to the configuration in FIG.

In the configuration using the position sensor as described above, since there is no need to provide a non-energization period for detecting an induced voltage, a sine wave drive can be realized, and a high-efficiency drive device with less vibration and noise is realized. it can. Although a Hall IC is used as a position sensor in this embodiment, it goes without saying that a similar effect can be obtained with a Hall sensor.

Embodiment 4 In the case of a normal brushless motor, as shown in the load torque-motor efficiency relationship diagram of FIG. 10, the motor efficiency decreases as the load torque decreases (under the condition of constant rotation) with respect to the load torque. Therefore, in the case of a pulsating load in which the load torque fluctuates with respect to one cycle of the mechanical angle, in this control, the control works so as to follow the pulsating load, and thus the average efficiency also decreases as shown in FIG. Therefore, the brushless motor shown in FIGS. 1 and 8 is a motor that maintains a constant efficiency with respect to load torque, specifically, a brushless motor that satisfies the relationship in the load torque-motor efficiency relationship diagram of FIG. By doing so, a more efficient brushless motor control device can be obtained.

Embodiment 5 A brushless motor drive control device as shown in FIGS. 1 and 8 may be used in a washing machine.
In the washing machine, the laundry 80 is unevenly distributed in the washing tub / dehydration tub 81 as shown in FIG. 12, but even in such a case,
It is possible to obtain stable rotation without rotational pulsation.

[0030]

As described above, according to the present invention, the rotational signal linearly interpolated is divided into a plurality of sections, linearly interpolated, and further divided into N to constitute a speed control loop.
It is possible to obtain a stable rotation free from fluctuations in the load torque.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a brushless motor drive control device according to a first embodiment.

FIG. 2 is a waveform diagram showing a drive voltage waveform and an induced voltage waveform in each phase coil of the brushless motor.

FIG. 3 is a speed / load torque chart.

FIG. 4 is a speed chart.

FIG. 5 is a speed chart.

FIG. 6 is a configuration diagram of a speed control loop portion in a control circuit of the brushless motor drive control device according to the first embodiment.

FIG. 7 is a configuration diagram of a speed control loop portion in a control circuit of the brushless motor drive control device according to the second embodiment.

FIG. 8 is a configuration diagram of a brushless motor drive control device according to a third embodiment.

FIG. 9 is a Hall signal chart.

FIG. 10 is a diagram showing a relationship between load torque and motor efficiency.

FIG. 11 is a diagram showing a relationship between load torque and motor efficiency.

FIG. 12 is a diagram showing a configuration of a washing machine.

FIG. 13 is a configuration diagram of a conventional brushless motor control driving device.

FIG. 14 is a waveform diagram showing a drive voltage waveform and an induced voltage waveform in each phase coil of the brushless motor.

[Explanation of symbols]

1 Inverter device, 2 Brushless motor, 3
AC power supply, 4 AC / DC converter, 5 inverter, 6 position detection circuit, 7 control circuit, 8 drive circuit, 9 Hall IC, 70 subtraction means, 71 linear interpolation means, 72 division means, 73 phase shifter device,
74 proportional control gain, 75 adding means, 76 f
/ V conversion means, 77 addition means, 78 second phase shifter, 80 laundry, 81 washing tub / dehydration tub.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masaaki Yabe 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation F-term (reference) 3B155 AA10 HB10 KB08 LA02 LA11 LB18 LC15 3H045 AA05 AA12 AA27 BA36 CA21 DA05 EA17 EA26 EA34 5H560 AA02 AA10 BB04 BB07 BB12 DA02 DA13 DA20 EB01 GG04 HA05 JJ15 SS07 UA02 XB09

Claims (8)

[Claims] 1. A brushless motor having a multi-phase armature winding and a permanent magnet rotor, detecting a position of the permanent magnet rotor, converting the position into a rotation signal, and converting the rotation signal. A brushless motor drive control device having an inverter device for driving and controlling the armature winding.
The rotation is divided into a plurality of sections to obtain a plurality of rotation signals, the rotation signals are linearly interpolated between adjacent rotation signals, and the linearly interpolated rotation signals are further divided into N sections. A brushless motor drive control device, wherein the drive of the armature winding is controlled by an applied voltage corresponding to the rotation speed of the motor. 2. The brushless motor drive control device according to claim 1, wherein N is a power of 2. 3. The brushless motor drive control device according to claim 1, wherein a deviation between the N-divided rotation signal and the rotation speed command is repeatedly controlled for each N division section. 4. The brushless motor drive according to claim 1, wherein the inverter detects the position of the permanent magnet rotor using an induced voltage generated in the armature winding. Control device. 5. The brushless motor according to claim 1, wherein the brushless motor has a position sensor, and the inverter detects the position of the permanent magnet rotor based on a signal from the position sensor. A brushless motor drive control device according to any one of the above. 6. The brushless motor drive control device according to claim 1, wherein the motor efficiency of the brushless motor does not decrease even in a low load region with respect to the maximum load torque. 7. A washing tub and driving the washing tub.
A washing machine comprising the brushless motor drive control device according to any one of claims 1 to 6. 8. A compressor comprising the brushless motor drive control device according to any one of claims 1 to 6.