JP2003174792A - Drive control device for brushless motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lessen the number of pieces of positional detection means and also to prevent the drop of motor properties. <P>SOLUTION: A Hall IC 24 is of analog output type, and it outputs voltage (0-6 V) proportionate to the magnetic flux density of an interlinked magnetic flux. This Hall IC 24 detects the position of each permanent magnet 10c of the rotor of a washer motor and the distribution of the magnetic flux density. A control circuit 19 controls the power supply to each-phase stator winding 10u, 10v, and 10w, based on the output of the above Hall IC 24. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless motor drive control device for driving and controlling a brushless motor having a permanent magnet rotor and a single-phase or multi-phase stator winding.

[0002]

Hall elements have been known as means for detecting the rotational position of a brushless motor. Since the output of the Hall element itself is a weak voltage signal, an amplifier and a comparator are usually integrated into an IC. The output of this conventional Hall IC is usually an "H" or "L" rectangular wave output. When the position of the permanent magnet rotor of the brushless motor is detected using such a conventional Hall IC, as shown in FIG. 13, in the case of a three-phase brushless motor, three Hall ICs 101, 102,
It is usual to provide 103.

In FIG. 13, the inverter circuit 10 is shown.
The input terminal 4 is connected to the DC power supply 105. This inverter circuit 104 includes switching elements 106 to 1
11, the output terminals A, B, C of which are stator windings 112u, 112v, 1 of the brushless motor 112.
It is connected to 12w. Although not shown, the rotor of the brushless motor 112 is a permanent magnet rotor.

Hall ICs 101, 102, 103
Are the digital signals H as shown in FIG.
1, H2, and H3 are output, and the waveforms are 120 ° out of phase with each other in electrical angle. Then, from these waveforms, the rotational positions of (1) to (6) are detected at one electrical angle of 360 °, and based on this, the three-phase stator windings (U,
V, W) are pseudo sine wave voltages Du, Dv, D
The control circuit 113 controls the switching elements 106 to 111 of the inverter circuit 112 to PW so as to apply w.
M control is performed to supply power to the stator windings 112u, 112v, 112w, and thereby drive control of the brushless motor 112.

However, in the above-mentioned conventional structure, when the number of Hall ICs as the position detecting means is large and there are variations in the mounting positions of the permanent magnets and variations in magnetic pole strength, motor torque fluctuations and cogging occur. That is, the motor characteristics may deteriorate.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a drive control device for a brushless motor which can reduce the number of position detecting means and contribute to preventing deterioration of motor characteristics. It is in.

[0007]

According to a first aspect of the present invention, in a drive control of a brushless motor having a permanent magnet rotor and a single-phase or multi-phase stator winding, the position of the permanent magnet is detected. As a position detecting means, an analog output type Hall IC that outputs a voltage according to the magnetic flux density
It is characterized in that a control section for controlling the power supply to each phase stator winding is provided based on the output of the Hall IC.

According to the first aspect of the present invention, the position and the magnetic flux density distribution of each permanent magnet can be detected by the analog output type Hall IC which outputs a voltage according to the magnetic flux density. It is possible to reduce the number of detecting means, and it is possible to detect not only the position detection but also the error in the mounting position of the permanent magnet and the variation in the magnetic pole strength. This makes it possible to control the power supply and contribute to the improvement of motor characteristics.

According to a second aspect of the present invention, the control unit has a reference pattern for the magnetic flux density distribution of the permanent magnet, and the Hall IC
Is detected and the difference between the reference pattern and the reference pattern is detected, and power supply to the stator windings of each phase is controlled based on the detection result.

When there is no error in the mounting position of the permanent magnets or variations in the magnetic pole strength, the magnetic flux density distribution of the permanent magnets as the rotating field shows a regular reference pattern. If there is an error in the mounting position of the permanent magnet or variations in magnetic pole strength,
The actual magnetic flux density distribution of the permanent magnet does not show a regular reference pattern.

According to the second aspect of the invention, however, the difference between the reference pattern for the magnetic flux density distribution of the permanent magnet and the output of the Hall IC, that is, the actual magnetic flux density distribution of the permanent magnet is detected. It becomes possible to detect whether or not there is an error in the mounting position and variations in the magnetic pole strength, and the size of the magnetic pole strength.The power supply to the stator windings of each phase is controlled based on this detection result. It is possible to control so as to eliminate errors and variations in magnetic pole strength, which contributes to improvement of motor characteristics.

A third aspect of the present invention is characterized in that the control section detects the magnetic flux density distribution of the permanent magnet from the output of the Hall IC for one rotation of the rotor to form the reference pattern. . According to this, the reference pattern according to each motor can be obtained.

According to a fourth aspect of the present invention, the control unit has a plurality of applied voltage patterns to each phase stator winding, and each applied voltage pattern is based on the output of the analog output type Hall IC. The feature is that power supply to the phase stator winding is controlled. According to the fourth aspect of the present invention, a plurality of motor drive patterns can be obtained, and rotation speed control and control according to load torque can be performed.

A fifth aspect of the present invention is characterized in that the Hall IC is provided so as to face a rotation surface of the rotation surface of the permanent magnet that is opposite to the stator winding. According to this, it is possible to prevent the output of the Hall IC from being affected by the field formed by the stator winding, and the power supply control can be accurately performed.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below with reference to FIGS. First, Figure 2
Shows the entire structure of the combined washing machine for dehydration according to the present embodiment. In FIG. 2, the washing machine main body 1 includes a rectangular box-shaped outer case 2 and a hollow top cover 3 provided on the upper surface of the outer case 2. A water receiving tank 4 as an outer tank is elastically suspended inside the outer box 2 by an elastic suspension mechanism 5, and a rotating tank 6 serving as a dehydrating tank and a washing tank is rotatable inside the water receiving tank 4. It is installed in.

A large number of dehydration holes 6a are formed in the peripheral wall of the rotary tank 6. A balance ring 7 is provided at the upper end of the rotary tank 6. Further, an agitator 8 is rotatably arranged on the inner bottom of the rotary tank 6.

A drive mechanism section 9 is arranged below the water receiving tank 4 in the outer box 2. This drive mechanism section 9
Includes a washing machine motor 10 composed of a direct drive type outer rotor type brushless motor, a clutch mechanism (not shown), and the like. A stator 10a of the washing machine motor 10 is attached to the water receiving tub 4 via a drive mechanism base 9a, and a rotor 10b is directly connected to the agitator 8. Then, in the washing process and the rinsing process, only the agitating body 8 is normally and reversely rotated by the washing machine motor 10, and in the dehydrating process, the agitating body 8 and the rotary tub 6 are rotated at high speed in synchronization. It has become. The washing machine motor 10 is an outer rotor type. In FIG. 5, the winding 10u in the stator 10a,
10v, 10w and a plurality of permanent magnets 10 of the rotor 10b
c is linearly expanded and shown.

A drain port 1 is provided at the bottom of the water receiving tank 4.
1 is formed. A drain valve 12 is provided at the drain port 11.
The drain hose 13 is connected via the. Further, the drain port 11 is provided with an air trap 14.
The pressure of the air trap 14 is configured to be guided to the water level sensor 16 (see FIG. 1) via the air tube 15. As is well known, the water level sensor 16 detects the water level in the water receiving tank 4 (rotating tank 6),
It is arranged inside the top cover 3. A lid 17 is provided on the top cover 3. Further, the operation panel 1 is provided on the front upper surface of the top cover 3.
8 are provided.

In FIG. 1 showing the electrical structure, a control circuit 19 is composed of a circuit mainly composed of a microcomputer, and functions as a washing machine control section for controlling the overall washing and also controls the washing machine motor 10. It is configured to function as a control unit that controls driving.

This control circuit 19 includes the operation panel 1
A switch signal from the switch input section 20 provided in the No. 8, a water level detection signal from the water level sensor 16, and a detection signal from the Hall IC 24 described later are input. Further, the control circuit 19 controls the drain valve 12 and the water supply valve 22 via the drive circuit 21, and further controls the washing machine motor 10 via the drive control device 23 which is a drive control device of the brushless motor. Has become. Also,
The water supply valve 22 is provided inside the rear portion of the top cover 3 shown in FIG. 2, and the water supply valve 22 is adapted to supply water into the rotary tank 6.

The Hall IC 24, as shown in FIG.
It has a Hall element 25 and an operational amplifier 26, and is of an analog output type. The output Vout is shown in FIG.
As shown in, the output voltage (0 to 6 V) is proportional to the magnetic flux density of the magnetic flux interlinking with the Hall IC 24. As shown in FIG. 5, the hall IC 24 is used for the washing machine motor 10
Is provided on the stator 10a side.

The drive control device 23 will be described with reference to FIG. The drive control device 23 includes a DC power supply circuit unit 27, an inverter circuit 28, a drive circuit 29, a PWM circuit 19a included in the control circuit 19, and control of the control circuit 19 by software of a microcomputer. It is composed of

The DC power supply circuit section 27 includes a rectifying circuit 30.
And a voltage doubler circuit including smoothing capacitors 31 and 32. An AC power supply 34 is connected to an input terminal of the rectifier circuit 30 via a reactor 33 in series. The output terminal of the rectifier circuit 30 has two DC power supply lines 35a and 35b.
Are connected, and smoothing capacitors 31, 32 are connected between them.
Are connected in series. These smoothing capacitors 31,
The common connection point of 32 is connected to one of the input terminals of the rectifier circuit 30.

Between the two DC power supply lines 35a and 35b,
The inverter circuit 28 is connected. The inverter circuit 28 includes six IGBTs 36a connected in a three-phase bridge.
.About.36f and a freewheel diode 37 connected in parallel with each other. Inverter circuit 2
The three output terminals 38 to 40 of No. 8 are three-phase stator windings 10u, 10v in the washing machine motor 10 stator 10a.
It is connected to each terminal of 10w.

The respective gates of the IGBTs 36a to 36f are connected to a drive circuit 29 which gives a drive signal via a photo coupler. The drive circuit 29 is the PWM circuit 19a.
And a PWM signal is given from the PWM circuit 19a. The control circuit 19 is mainly composed of a microcomputer and includes a ROM, a RAM and the like. Further, the water level sensor 16 is connected to the control circuit 19.

The control circuit 19 sequentially detects the magnetic pole positions of the permanent magnets 10c, and the phase windings 10u, 10v, 1
For 0w, PWM control is performed in order to create the energization waveforms Du, Dv, Dw of the pseudo sine wave voltage as shown in FIG. For example, the U phase will be described with reference to FIG. 7. That is, a PWM signal shown in FIG. 1B is generated from the carrier signal Sc and the control signal Vsin, and a PWM voltage equivalent to this PWM signal is applied to the U-phase winding 10u in a pseudo sinusoidal applied voltage Du, Dv and Dw. In this case, the effective value of the applied voltage changes by changing the amplitude of the control signal Vsin.

Now, the function of the control circuit 19 as the control means will be described with reference to the flowchart of FIG. For example, step S1 of this flowchart
The control shown in step S3 is performed prior to the washing operation or the dehydration operation. In step S1, the stator windings 10u, 10v, and 10w are energized by PWM control of a predetermined starting pattern to wash the washing machine motor 10
Start and control at a constant speed. This constant speed control is performed as follows. In this case, assuming that the number of permanent magnets 10c is "n" (even number), the control circuit 19 detects that the output voltage of the Hall IC 24 becomes the voltage V0 (corresponding to the magnetic flux density "0") as shown in FIG. Then, the number of times of detection is counted. PWM control is performed so that the number of detection times becomes “n + 1” (one rotation at “n + 1” counts from the start of “1” count) in the specified required time for one rotation of the motor. As a result, constant speed control is performed.

In the next step S2, the arbitrary generation timing of the predetermined voltage V0 is counted as the first count value "1" and the starting point is set. When the count value becomes "n", the next count value is set to "1" so that each count value and the corresponding permanent magnet 10c always correspond to each other. Further, in this step S2, the reference pattern of the magnetic flux density distribution of each permanent magnet 10c for one rotation is detected. This is detected as follows.

As shown in FIG. 9, the magnetic flux density Φ (“1” − at the timings (1) to (6) (temporally equal) from the “1” count time point (first permanent magnet).
(1)) to Φ (“1”-(6)) are measured and stored respectively, and thereafter, similarly, at the timings of (1) to (6) from the “2” to “n” count time points. Magnetic flux density Φ (“2”
-(1)) to Φ ("n"-(6)) are measured and stored. Thereby, the individual magnetic flux density distribution of each permanent magnet 10c can also be detected.

Then, the measured values of the magnetic flux density at the timing (1) of "1", "3", ... "N-1" are summed and divided by (n / 2) to obtain an average value. Then, the average value of the magnetic flux density at the timing of (1) is obtained, and similarly, (2) to (6)
The average value of the magnetic flux density at the timing is calculated. further,
The measured values of the magnetic flux densities at the timings of (1) of "2", "4", ... "N" are summed and divided by (n / 2) to obtain an average value. The average value of the magnetic flux density at the timing of (6) is calculated. In this way, the following (2)-
The average value of the magnetic flux density measurement values at the timing of (6) is calculated. The magnetic flux density measurement timing is set to the timings (1) to (6) for each permanent magnet for convenience, but it is actually a larger number. by this,
As shown in FIG. 10, the reference pattern Φk of the magnetic flux density distribution is formed (stored).

In the next step S3, "1"-
At each timing (1) to (6) of "n", the difference in the magnetic flux density distribution (magnetic flux density difference Φs) of each permanent magnet 10c with respect to the reference pattern Φk is detected, and the phase difference θs is also obtained. Is possible. Then, according to the difference, the PWM
Change the duty ratio of. For example, the reference pattern Φ
In the part where the magnetic flux density detected for k is small, PW
The on-duty ratio of M is increased, and when the detected phase of the magnetic flux density distribution is advanced, control such as early commutation is performed.
The applied voltages to u, 10v, and 10wc are controlled so as to be substantially the conduction waveforms Du, Dv, and Dw of the pseudo sine wave voltage (see FIG. 6). In this case, speed control and the like are performed while keeping the pseudo sine waveform as shown in FIG. 6 from the start to the end of dehydration.

According to the present embodiment as described above, the analog output type Hall IC 24 that outputs a voltage according to the magnetic flux density is used.
With this, it is possible to detect the position and magnetic flux density distribution of each permanent magnet 10c, and thus it is possible to detect not only the position detection but also the error in the mounting position of the permanent magnet 10c and the variation in magnetic pole strength. It is possible to perform power supply control in consideration of an error in the mounting position of the permanent magnet 10c and variations in magnetic pole strength, which contributes to improvement of motor characteristics.

Further, according to this embodiment, the Hall IC 24
Is detected and the difference between the magnetic flux density distribution of the permanent magnet 10c and the reference pattern is detected, and the power supply to the stator windings 10u, 10v, 10w of each phase is controlled based on the detection result. It is possible to detect whether or not there is an error in the mounting position of the magnet 10c, variation in magnetic pole strength, and the size. In particular, since the magnetic flux density distribution of the permanent magnet 10c is detected from the output of the Hall IC 24 for one rotation of the rotor to form the reference pattern, it is possible to obtain the reference pattern according to each motor. However, this reference pattern may be stored in the control circuit 19 in advance.

FIG. 11 shows a second embodiment of the present invention. In this embodiment, the control unit controls each phase winding 10u.
As the applied voltage pattern of the pseudo voltage applied to (10v, 10w), there are a pattern P1 shown in (a), a pattern P2 shown in (b), and a pattern P3 shown in (c),
The pattern P1 is controlled in the low speed range, the pattern P2 is controlled in the medium speed range, and the pattern P3 is controlled in the high speed range.
You may control so that it may become. According to this, a plurality of motor drive patterns can be obtained, and control according to the rotation speed and the load torque becomes possible. In this case, the rotation of the rotary tank 6 is smoothly increased.

FIG. 12 shows a third embodiment of the present invention. In this embodiment, the Hall IC 24 is used as the stator 10a of the rotating surfaces 10i and 10j of the permanent magnet 10c.
It is characterized in that it is provided so as to face the rotation surface 10j on the opposite side. According to this, it is possible to prevent the output of the Hall IC 24 from being influenced by the field formed by the stator windings 10u, 10v, and 10w, and the power feeding control can be accurately performed.

In the above embodiment, the present invention is applied to the drive control device for the motor of the washing machine, but other than this, it may be applied to the drive control device for the motor of the dryer, for example. . Further, in the above-mentioned embodiment, the brushless motor provided with the three-phase winding is exemplified, but this may be a single-phase winding. In addition, the present invention can be implemented with various modifications without departing from the scope of the invention.

[0037]

As is apparent from the above description, the present invention can reduce the number of position detecting means, and can detect not only the position detection but also the error of the mounting position of the permanent magnet and the variation of the magnetic pole strength. This makes it possible to perform power supply control in consideration of errors in the mounting positions of these permanent magnets and variations in magnetic pole strength, which contributes to improvement of motor characteristics.

[Brief description of drawings]

FIG. 1 is an electrical configuration diagram showing a first embodiment of the present invention.

[Figure 2] Vertical side view of the washing machine

FIG. 3 Circuit diagram of Hall IC

[Figure 4] Hall IC output characteristic diagram

FIG. 5 is a diagram showing a stator and a rotor in an expanded state

FIG. 6 is a diagram showing a voltage applied to a winding.

FIG. 7 is a waveform diagram for explaining PWM control.

FIG. 8 is a flowchart showing the control contents of the control circuit.

FIG. 9 is an output waveform diagram of a Hall IC for explaining how a reference pattern is formed.

FIG. 10 is a waveform diagram for explaining the difference between the reference pattern and the detected magnetic flux density.

FIG. 11 is a waveform diagram of an applied voltage pattern showing a second embodiment of the present invention.

FIG. 12 is a view corresponding to FIG. 5 showing a third embodiment of the present invention.

FIG. 13 is a view corresponding to FIG. 1 showing a conventional example.

FIG. 14 is a waveform diagram showing the relationship between the position detection and the voltage applied to the winding.

[Explanation of symbols]

6 is a rotary tub, 8 is a stirrer, 10 is a washing machine motor (brushless motor), 10a is a stator, 10b is a rotor, 10
c is a permanent magnet, 10u, 10v, 10w are stator windings,
Reference numeral 19 is a control circuit (control unit), 23 is a drive control device, 24
Is a Hall IC, 27 is a DC power supply circuit, and 28 is an inverter circuit.

Continued front page    F term (reference) 5H019 AA03 AA09 BB01 BB05 BB13                       BB20 BB24 CC04 CC06 DD01                 5H560 AA10 BB04 BB07 BB12 DA03                       DA17 DC07 DC13 EB01 EB05                       EC10 JJ15 RR01 SS07 TT07                       UA06 XA01 XA12

Claims (5)

[Claims] 1. In a drive control of a brushless motor having a permanent magnet rotor and a single-phase or multi-phase stator winding, the position detection means for detecting the position of the permanent magnet is based on the magnetic flux density. A brushless motor having one analog output type Hall IC that outputs a voltage, and a control unit that controls power supply to each phase stator winding based on the output of the Hall IC. Drive controller. 2. The control unit has a reference pattern for the magnetic flux density distribution of the permanent magnets, detects the difference between the output of the Hall IC and this reference pattern, and based on this detection result, sends to each phase stator winding. 2. The drive control device for a brushless motor according to claim 1, wherein the power supply control is performed. 3. The control unit is a Hall IC for one rotation of the rotor.
3. The drive control device for the brushless motor according to claim 2, wherein the reference pattern is formed by detecting the magnetic flux density distribution of the permanent magnets from the output of FIG. 4. The control section has a plurality of applied voltage patterns to each phase stator winding, and each phase stator winding is set so that each applied voltage pattern is based on the output of an analog output type Hall IC. The drive control device for the brushless motor according to claim 1, wherein power supply to the brushless motor is controlled. 5. The brushless motor drive according to claim 1, wherein the Hall IC is provided so as to face a rotating surface of the rotating surface of the permanent magnet opposite to the stator winding. Control device.