JPH09121584A - Device for detecting position of magnetic pole and device for driving brushless dc motor using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the absolute positions of continuous magnetic poles with high accuracy by detecting the absolute positions from the section of prescribed one selected out of three converted and corrected magnetic pole position detecting signals. SOLUTION: A converting and correcting means 6 converts and corrects three magnetic pole position detecting signals the phases of which are generated and outputted by means of a detecting signal generating section 12 so that their phases can be shifted from each other by 120 deg.. A signal selecting means 103 selects prescribed one out of the three converted and corrected magnetic pole position detecting signals. A relative magnetic pole position detecting means 104 detects a relative magnetic pole position from the value of the selected detecting signal. An absolute magnetic pole position detecting means 105 detects the absolute positions of continuous magnetic poles from the section of the selected detecting signal and relative magnetic pole position. Therefore, the absolute positions of continuous magnetic poles can be detected with high accuracy by maintaining the magnetic pole position detecting accuracy at a high level regardless of the magnetizing waveform of the magnetic poles, whether a sine waveform or a trapezoidal waveform.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic pole position detecting device and a brushless DC motor driving device, and more particularly, to a magnetic pole position detecting device for detecting a magnetic pole position using a Hall element, the magnetic pole position detecting device and a brushless DC motor. The present invention relates to a brushless DC motor driving device using a 180-degree conduction type inverter that drives a motor in sine wave PWM.

[0002]

2. Description of the Related Art A conventional magnetic pole position detecting device for a brushless DC motor driving device using a Hall element is disclosed in Japanese Unexamined Patent Publication No. Hei 4 (1998) -1998.
As described in Japanese Patent No. 295293, a magnetic pole position is detected by a linear approximation area of an output signal from two magnetic pole position detection elements such as two Hall elements arranged with a 90 electrical phase shift, and a brushless DC motor is driven. Met.
The magnetic pole position is detected by creating an inverted signal of each of two sine wave detection signals that are 90 degrees out of phase, and using a linear approximation region that is an intersection section between the non-inverted signal and the four sine wave signals of the inverted signal. The absolute magnetic pole position was detected.

As another method, a method of driving a brushless DC motor using an encoder is widely used in servo motors and the like.

[0004]

However, since the above-mentioned conventional technique uses the linear approximation region of the 90-degree section of the sine wave signal, the vicinity of the switching point becomes non-linear, and
The influence of variations in the elements that make up the inverting circuit, etc.
The position detection accuracy might be reduced. Further, in the case where the magnetic poles of the motor are trapezoidal-wave magnetized, it is difficult to detect the magnetic pole position when the upper base of the trapezoidal wave has an electrical angle of 90 degrees or more.

An object of the present invention is that the magnetic pole magnetizing waveform is a sine wave,
An object of the present invention is to provide a magnetic pole position detection device that maintains a high detection accuracy of a magnetic pole position regardless of a trapezoidal wave and detects highly accurate continuous absolute magnetic pole positions.

A further object of the present invention is to provide a magnetic pole position detecting device which eliminates the influence of variations in detection accuracy due to elements or the like constituting a circuit by digital processing and can easily interface with a microcomputer. It is in.

Further, an object of the present invention is to use the above magnetic pole position detecting device for detecting a magnetic pole position of a brushless DC motor driving device so that continuous magnetic pole positions can be detected and sine wave driving or rectangular wave driving can be performed at low cost. An object of the present invention is to provide a drive device for a brushless DC motor with low vibration and low noise.

Another object of the present invention is to reduce the vibration and noise generated by the resonance of the washing tub by using the driving device for the brushless DC motor as a driving device for a washing tub of a washing machine or a pulsator. is there. Another object is to reduce the vibration of a fan motor using a brushless DC motor.

[0009]

In order to achieve the above object, the present invention provides a magnetic pole position detecting element portion for detecting the magnetic pole position of a rotating body by means of three magnetic pole position detecting elements utilizing magnetic changes, and In a magnetic pole position detection device having a detection signal generation unit that generates a magnetic pole position detection signal based on a magnetic pole position and a control unit that controls the magnetic pole position detection based on the magnetic pole position detection signal, the control unit includes the detection signal. Conversion correcting means for converting and correcting the three magnetic pole position detection signals generated and output by the generator and having a phase difference of 120 degrees from each other, and one predetermined magnetic pole position detection signal from among the three magnetic pole position detection signals subjected to the conversion correction. Signal selection means, a relative magnetic pole position detection means for detecting a relative magnetic pole position from the value of the selected magnetic pole position detection signal, and a section of the selected magnetic pole position detection signal And having an absolute magnetic pole position detection means for detecting a consecutive absolute magnetic pole position from said relative magnetic pole position.

Another feature of the present invention is to detect a magnetic pole position based on the magnetic pole position, and a magnetic pole position detecting element portion for detecting the magnetic pole position of a rotating body by two magnetic pole position detecting elements utilizing magnetic changes. In a magnetic pole position detection device having a detection signal generation unit that generates a signal and a control unit that controls the magnetic pole position detection based on the magnetic pole position detection signal, the control unit outputs 120 generated and output by the detection signal generation unit. A digital converting means for converting two magnetic pole position detection signals whose phases are shifted by an analog / digital converter into a digital detected value, and a third digital detected value is calculated from the converted two digital detected values. Estimated position detecting means for obtaining digital detection values for three phases, and a predetermined one digital detection value is selected from the digital detection values for the three phases. Signal selection means, relative magnetic pole position detection means for detecting a relative magnetic pole position from the selected digital detection value, and a section of the magnetic pole position detection signal corresponding to the selected digital detection value and the relative magnetic pole position. And an absolute magnetic pole position detecting means for detecting the absolute magnetic pole position.

Another feature of the present invention is that in a brushless DC motor driving device using the magnetic pole position detecting device, a PWM drive signal is generated based on the absolute magnetic pole position detected by the magnetic pole position detecting device. It is provided with a drive signal creating means for creating and outputting to the inverter to drive the brushless DC motor.

Another feature of the present invention is that the drive device of the brushless DC motor is used in a rotation drive unit such as a fan, a washing tub of a washing machine, and a pulsator.

Further, another feature of the present invention is that a magnetic pole position detecting element step for detecting the magnetic pole position of the rotating body by three magnetic pole position detecting elements by utilizing magnetic change, and magnetic pole position detection based on the magnetic pole position. In the magnetic pole position detecting method including a detection signal generating step of generating a signal and a control step of controlling the magnetic pole position detection based on the magnetic pole position detecting signal, the control step is generated and output by the detection signal generating step. A conversion correction step of converting and correcting three magnetic pole position detection signals whose phases are shifted by degrees, and a signal selecting step of selecting a predetermined one magnetic pole position detection signal from the three magnetic pole position detection signals subjected to the conversion correction, A relative magnetic pole position detecting step of detecting a relative magnetic pole position from the value of the selected magnetic pole position detection signal; and the selected magnetic pole. Lies in having an absolute magnetic pole position detection step of detecting the absolute magnetic pole position continuous from the 置検 detection signal of the section and the relative magnetic pole position.

Further, another feature of the present invention is that a magnetic pole position detecting element step in which two magnetic pole position detecting elements detect the magnetic pole position of a rotating body by utilizing a magnetic change, and magnetic pole position detection based on the magnetic pole position. In the magnetic pole position detecting method including a detection signal generating step of generating a signal and a control step of controlling the magnetic pole position detection based on the magnetic pole position detecting signal, the control step is generated and output by the detection signal generating step. A digital conversion step of converting two magnetic pole position detection signals whose phases are shifted by an analog / digital converter into a digital detection value, and a third digital detection value is calculated from the converted two digital detection values. An estimated position detecting step for obtaining digital detection values for three phases, and A signal selection step of selecting a predetermined one digital detection value, a relative magnetic pole position detection step of detecting a relative magnetic pole position from the selected digital detection value, and a magnetic pole position detection signal corresponding to the selected digital detection value. And an absolute magnetic pole position detecting step of detecting a continuous absolute magnetic pole position from the relative magnetic pole position.

According to the present invention, the magnetic pole position detecting element portion is
The magnetic pole position of the rotating body is detected by the three magnetic pole position detecting elements by utilizing the magnetic change. The detection signal generation unit generates a magnetic pole position detection signal based on the magnetic pole position. The conversion correction means of the control unit performs conversion correction of the three magnetic pole position detection signals generated and output by the detection signal generation unit and having a phase shift of 120 degrees. The signal selection means selects one predetermined magnetic pole position detection signal from the three magnetic pole position detection signals that have been converted and corrected. The relative magnetic pole position detecting means detects the relative magnetic pole position from the value of the selected magnetic pole position detection signal. The absolute magnetic pole position detecting means detects a continuous absolute magnetic pole position from the selected section of the magnetic pole position detection signal and the relative magnetic pole position.

As a result, regardless of whether the output signal waveform of the magnetic pole position detection element is a sine wave or a trapezoidal wave, the relative magnetic pole position can be accurately determined by using the detection value within the predetermined electrical angle range of the magnetic pole position detection signal waveform. A highly accurate continuous absolute magnetic pole position can be obtained from the detected and selected magnetic pole position detection signal section and the relative magnetic pole position.

Furthermore, the output signal waveform of the magnetic pole position detecting element can be digitally sampled to obtain a highly accurate continuous digital absolute magnetic pole position by digital processing, and the influence of the output variation of the elements constituting the circuit can be suppressed. At the same time, the data can be easily processed by connecting to a computer.

Further, the output variation of the amplitude and offset amount of the output signal waveform of each magnetic pole position detecting element is detected by using the maximum and minimum values of the digital detection value, and the correction amount of the digital detection value is determined and corrected. As a result, it is possible to perform highly accurate magnetic pole position detection by eliminating the influence of variations in the output of circuit component elements such as the magnetic pole position detection element.

Furthermore, since the magnetic pole position of the brushless DC motor can be detected with high accuracy by using the magnetic pole position detecting device composed of a small and low-cost Hall element, the sine wave PWM drive or the rectangular wave PWM drive of the brushless DC motor is easy. It is possible to realize low vibration and low noise operation.

Further, sine wave PWM drive or rectangular wave P
By operating a brushless DC motor for a variable speed fan or a brushless DC motor for a fully automatic washing machine using a brushless DC motor drive device capable of WM driving, continuous variable speed without avoiding mechanical resonance points. Driving can be realized.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION A magnetic pole position detecting device and a brushless DC motor driving device using the same according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a functional configuration of a magnetic pole position detecting device and a brushless DC motor driving device according to an embodiment of the present invention. As the motor of one embodiment of the present invention, for example, a brushless DC motor 1 having two poles of a permanent magnet field is used.
A phase winding 1B, a two-pole permanent magnet rotor 1A, and a magnetic pole position detecting element unit 2 are provided.

The drive device 10 for the brushless DC motor is
The magnetic pole position detecting device 100, the speed controller 300, the drive signal generating means 200, and the inverter 3 are included.

The magnetic pole position detecting device 100 comprises a magnetic pole position detecting element section 2, a detection signal generating section 12, and a control section 5. The magnetic pole position detection element unit 2 detects the detection signals (Sa + and Sa-, Sb
Three magnetic pole position detecting elements that output + and Sb-, Sc + and Sc-),
For example, it has Hall elements (1Ha, 1Hb, 1Hc). Detection signals (Sa + and Sa-, Sb + and Sb-, Sc +) output by the magnetic pole position detection element unit 2
And Sc-) are amplifiers (12a, 12b, 12c) of the detection signal generation unit 12
Three amplified signals with a phase difference of 120 degrees in electrical angle due to
(S2a, S2b, S2c).

The control section 5 is composed of a conversion correction means 6, a signal selection means 103, a relative magnetic pole position detection means 104, and an absolute magnetic pole position detection means 105, which are the one-chip microcomputer 4 (hereinafter , Which is referred to as a microcomputer) as a program or as a hardware analog / digital converter.

The conversion correction means 6 is the digital conversion means 1
01 and the correction means 102. The digital conversion means 101 digitally samples the amplified signals (S2a, S2b, S2c) by an analog / digital converter, and outputs digital detection values B1 for three phases. Correction means 102
Corrects the influence of the output variations of the circuit elements such as the Hall elements (1Ha, 1Hb, 1Hc) and the amplifiers (12a, 12b, 12c), and outputs the correction detection value B2 to the signal selecting means 103.

The signal selection means 103 outputs one predetermined detection value B3 selected from the three detection values to the relative magnetic pole position detection means 104, and also outputs a section signal B4 indicating the section of the selected detection signal. Output. The absolute magnetic pole position detection means 105 receives the relative magnetic pole position B5 output by the relative magnetic pole position detection means 104 and the section signal B4, and outputs the absolute magnetic pole position B6.

The speed controller 300 calculates the speed from the absolute magnetic pole position B6 and outputs the voltage command Vord. The drive signal creating means 200 uses the sine wave PWM signal device 2 based on the voltage command Vord.
01 or the rectangular wave PWM signal device 202 is selected, and the drive signal DR for driving the inverter 3 using the digital absolute magnetic pole position signal B6 of the absolute magnetic pole position detection means 105.
Outputs V and operates the brushless DC motor 1.

Next, the operation of detecting the magnetic pole position will be described in detail.

The output signals of the Hall elements (1Ha, 1Hb, 1Hc) of each part output signal waveforms (Sa + and Sa-, Sb + and Sb-, Sc + and Sc-) proportional to the magnetic poles and magnetic flux of the permanent magnet rotor. Amplifier (1
2a, 12b, 12c) can input to the analog / digital converter constituting the digital conversion detecting means 101 in the microcomputer 4 0-5V amplified signal (S2a, S2b, S2c)
Is input to the digital conversion means 101.

The digital converting means 101 samples the three amplified signals (S2a, S2b, S2c) by the analog / digital converter at fixed time intervals. Sampled 3
With respect to one digital detection value B1, the offset amount or amplitude error of the amplified signals (S2a, S2b, S2c) is detected by the correction means 102 based on the maximum and minimum values for each phase, and the digital detection value B1 is corrected. In addition, the correction detection value B2 from which the influence of the output variation of the Hall element or the elements constituting the circuit is removed is output.

In the signal selecting means 103, the electrical angle most suitable for detecting the magnetic pole position is -30 to 30 degrees or 150 to 2
A predetermined one of the three correction detection values B2 within the range of 10 degrees is selected and output as the selection detection value B3, and the section signal B indicating the phase and section of the selected detection signal is selected.
4 is output.

In the relative magnetic pole position detecting means 104, the relationship between the angle and the value of the selected detection value B3 detected in the magnetic pole position range of −30 to 30 degrees in electrical angle (the same applies in the range of 150 to 210 degrees). Values) are preliminarily mapped on the ROM table, and a table search is performed from the value of the selected detection value B3 to obtain a relative relative magnetic pole position B5 in the range of -30 to 30 degrees.

In the absolute magnetic pole position detecting means 105, the angle reference value (0, 60, 120,
One of 180,240,300 degrees) is detected, and the relative magnetic pole position B5 which is the angle reference value and the value of -30 to 30 degrees
And (when the angle reference value is 60, 180, 300 degrees, subtraction is performed because the relationship between the selected detection value B3 and the angle is reversed), and the absolute magnetic pole position of -30 to 330 degrees for one electrical angle cycle is obtained. Further, the absolute magnetic pole position B6 is obtained by adding 30 degrees as the offset amount.

This makes it possible to obtain a highly accurate absolute magnetic pole position by using a small, lightweight, inexpensive Hall element. Further, since the obtained absolute magnetic pole position is a digital quantity, data processing by a computer is easy.

Further, in this embodiment, the absolute magnetic pole position B6
Is used to create a drive signal for a brushless DC motor and drive it. The speed controller 300 outputs the voltage command Vord so that the speed command Nord and the rotation speed calculated from the change amount of the absolute magnetic pole position B6 per time match.

The drive signal creating means 200 has a sine wave PWM signal device 201 and a rectangular wave PWM signal device 202 for creating a PWM signal, which are two driving methods of the brushless DC motor, and has a speed command Nord. The operating state is detected from the sine wave PWM signal device 201 according to the operating state.
The brushless DC motor can be operated with low vibration and low noise by switching between the rectangular wave PWM signal device 202 and the rectangular wave PWM signal device 202.

FIG. 2 shows an angular range in the magnetic pole position detecting device of FIG. 1, and shows a section of a range of −30 to 330 degrees in one cycle of electrical angle. The selection signal is a signal selected by the signal selection means 103 based on the magnitude relation of the three detection signals, and corresponds to the angle of the angle range and the section signal B4. The angle reference value is the center value of the angle range, and the angle reference value and the relative magnetic pole position B
5 is a reference angle for obtaining the absolute magnetic pole position B6 by addition and subtraction. Here, the value when the electrical angle is 30 degrees or 150 degrees is UR, and the value when the electrical angle is -30 degrees or 210 degrees is DR. For comparison of the magnitude relationship, the three detection signals may be compared with each other to obtain the magnitude relationship, but it is also possible to obtain by comparing each detection signal with UR or DR.

FIG. 3 shows the operation of detecting the magnetic pole position in the magnetic pole position detecting device of FIG. 1, when the magnetic pole of the motor is magnetized with a sine wave. As shown in (a), the detected signal waveform (Sa, Sb, Sc) of the Hall element is the potential difference (number) between the two signals (Sa + and Sa-, Sb + and Sb-, Sc + and Sc-) from the Hall element. 100 mV) is shown. As shown in (b), the amplified signal (S2
a, S2b, S2c) are amplified and offset in the range of 0 to 5V so that the detection signal (Sa, Sb, Sc) of the sine wave Hall element that changes to positive or negative can be detected by the analog / digital converter. Give a level. The relative magnetic pole position B5 in (f) is U indicated by a thick line from the digital detection values B1a, B1b, B1c of the three phases shown in (c), (d) and (e).
Only the part within the range of R to DR is selected. Further, from the relationship shown in FIG. 2 and the relative magnetic pole position B5,
As shown in (g), continuous absolute magnetic pole positions B6 can be obtained.

FIGS. 4, 5, and 6 show a correction method in the magnetic pole position detection device of FIG. 1, in which FIG. 4 shows the offset amount detection, FIG. 5 shows the amplitude error detection, and FIG. 6 shows the correction method. A flow chart is shown.

Although only one phase is shown in FIGS. 4 and 5, the same applies to the other two phases. Also, the broken line in the figure shows the ideal amplified signal stored in advance in the microcomputer 4, the solid line shows the actual amplified signal S2a, and the thick line shows the section within the range of UR and DR for obtaining the ideal relative magnetic pole position. There is. Zero is an intermediate value between UR and DR. In the detection of the offset amount in FIG. 4, the ideal maximum value RMax and the minimum value Rmin are obtained in advance, and the offset amount is detected from the maximum value Max and the minimum value Min of the detected amplified signal using (Equation 1). To do.

[0042]

(Equation 1)

In the amplitude error detection shown in FIG. 5, the ideal maximum value RMax and minimum value Rmin and the maximum value Ma of the detected amplified signal are detected.
The amplitude error is detected by using (Equation 2) from x and the minimum value Min.

[0044]

(Equation 2)

In FIG. 6, it is judged whether or not the motor is rotating at a low speed immediately after the motor is started (step 501), the offset correction amount and the amplitude correction amount are detected only at the low speed, and in other cases, the detected digital detection value is offset. Correction (5
10) and amplitude correction (511) are performed. These detections and corrections are performed for each of the three phases.

When the motor is at low speed, the maximum value Ma for each of the three phases is
x and the minimum value Min are detected (502), and the offset amount is calculated (503). It is judged whether the obtained offset amount is within a predetermined allowable range (504), and if it is within the allowable error range, the offset correction amount is cleared (512). If it is outside the allowable error range, set the offset correction amount (505) and set the maximum value.
Offset correction of Max and minimum value Min is performed (506).

Next, the amplitude error is calculated (50
7), it is judged whether the amplitude error is within a predetermined allowable range (5
08), if it is within the allowable error range, the amplitude correction amount is cleared (5
13). If it is outside the allowable error range, set the amplitude correction amount
(509).

As described above, the amplitude and the offset amount of the output signal waveform of each Hall element are detected by using the maximum and minimum values of the digital detection value, and the correction amount of the digital detection value is determined and corrected. It is possible to detect the magnetic pole position with high accuracy by eliminating the influence of variations in the circuit components such as the Hall element. Here, the allowable range is a value obtained by an experiment in advance and stored in the ROM of the microcomputer 4.

FIG. 7 shows motor characteristics of the brushless DC motor shown in FIG. Rectangular wave PWM with 120 degree energization drive
Since the power supply voltage Ed can be effectively used during rectangular wave driving using the signal device 202, it is suitable during startup or acceleration operation that requires a large output torque. On the other hand, at the time of sine wave driving using the sine wave PWM signal device 201 which is energized by 180 degrees, a sinusoidal voltage can be applied to reduce the torque ripple, which is suitable when low vibration / low noise operation is required. There is.

Sine wave PWM signal device 201 and rectangular wave PWM
For switching to the signal device 202, the speed controller 30 of FIG.
The operating condition is determined by the speed command Nord of 0, and the rectangular wave PWM signal device 202 is selected at the time of startup and high load operation,
Otherwise, the sine wave PWM signal device 201 is used. As a result, low vibration and low noise operation can be realized even for those requiring a large output torque.

In the embodiment of the present invention, the case where three Hall elements are used is shown. However, when the output signal of the Hall element is in the range of −30 to 30 degrees or 150 to 210 degrees in electrical angle, Sa + S.
In the magnetized so that b + Sc = 0, two Hall elements are used to detect the two phases, and from the detected values of the two phases, the signal of the third phase is output using an operational amplifier or the like. Seek 3
A phase detection signal may be obtained. Further, although the relative magnetic pole position detection means uses the ROM table to obtain the relative magnetic pole position, an approximate expression such as a linear approximate expression may be used.

FIG. 8 shows a functional configuration of a magnetic pole position detecting device according to another embodiment of the present invention. The magnetic pole position detection device 150 of FIG. 8 is arranged with a phase shift of 120 degrees in electrical angle.
Two Hall elements (1Ha, 1Hb) detect two-phase detection signals by the digital conversion means 101 of the control unit 50, and use the two digital detection values detected by the estimated position detection means 107 to perform a third digital detection. The calculation of the value is different from that of the magnetic pole position detecting device 100 of FIG. 1, and other operations with the same reference numerals are the same.

In this embodiment, two amplified signals (S2a, S2b)
Is digitally sampled by digital conversion means,
The detected two digital detection values (B7a, B7b) are output to the estimated position detection means 107. In the estimated position detection means 107, one estimated digital detection value B7c is-(B7a +
B7b) and three digital detection values (B1a, B1b,
Output as B1c). As a result, even if the number of Hall elements is two, continuous absolute magnetic pole positions can be efficiently detected.

FIG. 9 shows an embodiment of the construction of a washing machine using the brushless DC motor driving device of the present invention. In the present embodiment, the operation control device 810 holds the operation pattern of strong washing, soft washing, etc. as the motor speed command Nord according to the washing course, and operates the washing machine at a variable speed.
That is, the operation is performed by changing the pattern of the speed command Nord according to the amount of laundry. The brushless DC motor driving device 10 controls the speed of the brushless DC motor 1 so as to match the speed command output from the operation control device 810, and drives the washing tub 801 and the pulsator 803 via the pulley 804 and the belt 805. . In the present embodiment, in addition to the variable speed operation during washing, even when the rotation speed during dehydration is continuously changed, a sine wave drive operation with less torque ripple can be performed with an inexpensive configuration using a Hall element, It is possible to realize low vibration and low noise operation.

Further, in the above-described embodiments, the case where the magnetic pole position detecting device of the present invention is applied to the drive device of the brushless DC motor and the case of the washing machine using the brushless DC motor are described. By using the drive device of the brushless DC motor having the magnetic pole position detection device of the present invention for a fan or the like, it is possible to easily achieve low vibration and low noise. Further, the present invention is not limited to this, and can be widely applied to magnetic pole position detection devices for various other rotating bodies, and position measurement in drive control of a linearly moving power source such as a linear motor using a permanent magnet. Can also be applied to.

[0056]

According to the present invention, the electrical angle of the detection signal is -30 to 30 degrees or 150 using the output signal of the small and low-cost Hall element without using an encoder or the like.
By selecting a detection value in the range of up to 210 degrees and using the selected detection value, the relative magnetic pole position is detected with high accuracy, and a highly accurate continuous absolute position is detected from the selected detection signal section and the relative magnetic pole position. The magnetic pole position can be obtained.

Further, according to the present invention, the sine wave PWM drive with a small torque ripple and the rectangular wave PW with a large starting torque are used.
By performing variable speed operation of the washing machine using the drive device of the brushless DC motor capable of M drive, continuous low noise can be achieved without avoiding mechanical resonance point until reaching high speed during dehydration operation. Variable speed operation can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a functional configuration of a magnetic pole position detection device and a brushless DC motor drive device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an angular range in the magnetic pole position detection device of FIG.

FIG. 3 is a diagram showing a magnetic pole position detection operation in the magnetic pole position detection device of FIG.

FIG. 4 is a diagram showing detection of an offset amount of the amplified signal of FIG.

5 is a diagram showing detection of an amplitude error of the amplified signal of FIG.

FIG. 6 is a flowchart of the correction process of the amplified signal of FIG.

FIG. 7 is a diagram showing motor characteristics of the brushless DC motor of FIG.

FIG. 8 is a block diagram showing a functional configuration of a magnetic pole position detection device according to another embodiment of the present invention.

FIG. 9 is a diagram showing an embodiment of the structure of a washing machine using the brushless DC motor drive device of the present invention.

[Explanation of symbols]

1 ... Brushless DC motor, 2, 20 ... Magnetic pole position detection element section, 3 ... Inverter, 4 ... Microcomputer,
5, 50 ... Control unit, 6 ... Conversion correcting means, 10 ... Driving device, 12, 120 ... Detection signal generating unit, 100, 150 ...
Magnetic pole position detecting device, 101 ... Digital converting means, 10
2 ... Correction means, 103 ... Signal selection means, 104 ... Relative magnetic pole position detection means, 105 ... Absolute magnetic pole position detection means, 10
7 ... Estimated position detection means, 300 ... Speed controller, 200 ...
Drive signal generating means, 201 ... Sine wave PWM signal device, 20
2 ... Square wave PWM signal device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kunio Miyashita 1-1-1 Higashitaga-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Electric Appliances Division (72) Inventor Takeo Konno 1-chome, Higashi-taga-cho, Ibaraki No. 1 No. 1 Company within Hitachi, Ltd. Electric Appliance Division

Claims (10)

[Claims] 1. A magnetic pole position detecting element portion for detecting a magnetic pole position of a rotating body by three magnetic pole position detecting elements utilizing magnetic changes, and a detection signal generating portion for generating a magnetic pole position detection signal based on the magnetic pole position. And a magnetic pole position detection device having a control unit that controls the magnetic pole position detection based on the magnetic pole position detection signal, wherein the control unit outputs 1 generated by the detection signal generation unit.
Conversion correction means for converting and correcting three magnetic pole position detection signals whose phases are shifted by 20 degrees, and signal selecting means for selecting one predetermined magnetic pole position detection signal from the three corrected and corrected magnetic pole position detection signals. A relative magnetic pole position detecting means for detecting a relative magnetic pole position from the value of the selected magnetic pole position detection signal, and an absolute magnetic pole position which is continuous from the section of the selected magnetic pole position detection signal and the relative magnetic pole position. A magnetic pole position detecting device, comprising: absolute magnetic pole position detecting means. 2. The conversion correction means according to claim 1,
Digital conversion means for converting the magnetic pole position detection signal into a digital detection value by an analog / digital converter;
A correction unit that detects the output variation of the magnetic pole position detection element unit from the maximum and minimum values of the converted digital detection value, obtains a correction amount from the detected output variation, and corrects the digital detection value. A magnetic pole position detecting device comprising: 3. A magnetic pole position detection element section for detecting the magnetic pole position of a rotating body by two magnetic pole position detection elements utilizing magnetic changes, and a detection signal generation section for generating a magnetic pole position detection signal based on the magnetic pole position. And a magnetic pole position detection device having a control unit for controlling the magnetic pole position detection based on the magnetic pole position detection signal, wherein the control unit generates and outputs 1
A digital converting means for converting two magnetic pole position detection signals having a phase difference of 20 degrees into a digital detection value by an analog / digital converter, and a third digital detection value calculated from the converted two digital detection values. Seeking,
Estimated position detecting means for obtaining digital detection values for three phases;
The signal selection means for selecting a predetermined one digital detection value from the three-phase digital detection values, the relative magnetic pole position detection means for detecting the relative magnetic pole position from the selected digital detection value, and the selection. A magnetic pole position detecting device comprising: an absolute magnetic pole position detecting means for detecting a continuous absolute magnetic pole position from a section of a magnetic pole position detection signal corresponding to the digital detection value and the relative magnetic pole position. 4. The magnetic pole position detecting device according to claim 1, wherein the absolute magnetic pole position is detected based on the absolute magnetic pole position.
A drive device for a brushless DC motor, comprising drive signal creation means for creating a PWM drive signal and outputting it to an inverter to drive the brushless DC motor. 5. The sine wave PWM signal generator for generating a sine wave PWM drive signal, and the rectangular wave PW for generating a rectangular wave PWM drive signal according to claim 4.
An apparatus for driving a brushless DC motor, comprising: an M signal device. 6. The rectangular wave PWM signal device according to claim 5, wherein the rectangular wave PWM signal device is used when an output at the time of starting the brushless DC motor or acceleration is required, and the sine wave PWM signal device is
A drive device for a brushless DC motor, which is used when the brushless DC motor reaches a target rotation speed and is driven with low vibration. 7. The washing machine according to claim 4, wherein the drive device for the brushless DC motor is used as a drive machine for a washing tub or a pulsator in a fully automatic washing machine. 8. A magnetic pole position detecting element step of detecting magnetic pole positions of a rotating body by three magnetic pole position detecting elements by utilizing magnetic changes, and a detection signal generating step of generating a magnetic pole position detection signal based on the magnetic pole positions. And a magnetic pole position detection method having a control step of controlling the magnetic pole position detection based on the magnetic pole position detection signal, the control step comprising three phase shifts of 120 degrees generated and output by the detection signal generation step. A conversion correction step of converting and correcting the magnetic pole position detection signal; a signal selection step of selecting a predetermined one magnetic pole position detection signal from the three converted and corrected magnetic pole position detection signals; and the selected magnetic pole position detection signal. Relative magnetic pole position detection step of detecting the relative magnetic pole position from the value of An absolute magnetic pole position detecting step of detecting a continuous absolute magnetic pole position from the magnetic pole position. 9. The digital conversion step according to claim 8, wherein the conversion correction step converts the magnetic pole position detection signal into a digital detection value by an analog / digital converter, and a maximum of the converted digital detection value. And a minimum value, an output variation of the magnetic pole position detection element unit is detected, a correction amount is obtained from the detected output variation, and a correction step of correcting the digital detection value is provided. . 10. A magnetic pole position detecting element step of detecting a magnetic pole position of a rotating body by two magnetic pole position detecting elements by utilizing a magnetic change, and a detection signal generating step of generating a magnetic pole position detection signal based on the magnetic pole position. And a magnetic pole position detection method having a control step of controlling the magnetic pole position detection based on the magnetic pole position detection signal, wherein the control step comprises two magnetic poles that are 120 degrees out of phase generated and output by the detection signal generation step. A digital conversion step of converting the position detection signal into a digital detection value by an analog / digital converter;
An estimated position detection step of obtaining a digital detection value for three phases by calculating a third digital detection value from one digital detection value, and a predetermined one digital detection value from the digital detection values for the three phases. And a relative magnetic pole position detecting step of detecting a relative magnetic pole position from the selected digital detection value,
A magnetic pole position detecting device comprising: an absolute magnetic pole position detecting step of detecting a continuous absolute magnetic pole position from a section of the magnetic pole position detection signal corresponding to the selected digital detection value and the relative magnetic pole position.