JP2023011158A - Motor drive device and electric pump device - Google Patents

Abstract

To provide a motor drive device capable of suppressing harmonic components at low cost without using a sensor having high resolution and a microcomputer with high computing power.SOLUTION: A motor drive device 1 drives a 3-phase motor 40, and includes an inverter 30 for driving the motor 40 and a controller 50 for controlling the inverter 30. The controller 50 controls the inverter 30 on the basis of an output command of a specific wave shape. The shape of the specific wave is a square wave having two concave portions between rising and falling portions.SELECTED DRAWING: Figure 2

Description

The present invention relates to a motor drive device and an electric pump device.

A so-called “120-degree energization control method” is known as a motor control method. In this method, the direction of the combined magnetic flux generated by the U-phase coil, the V-phase coil, and the W-phase coil is changed by switching the current-carrying two layers of the U-phase, V-phase, and W-phase at every 60 degrees (electrical angle). are switched according to the rotational position of the rotor to rotate the rotor.

For example, Japanese Patent Laying-Open No. 2012-147561 (Patent Document 1) discloses an inverter control system using such a 120-degree conduction control method. In this inverter control system, a 120-degree conduction pattern is generated according to the electrical angle of the motor, and a PWM (Pulse Width Modulation) signal is generated based on the generated 120-degree conduction pattern and the magnitude of the inverter input current. A gate signal for a switching element that constitutes an inverter is generated by logically synthesizing the above (see Patent Document 1).

JP 2012-147561 A

The 120-degree energization control method switches the energization pattern every 60 degrees (electrical angle), and the voltage generated by the inverter and applied to the motor has a rectangular waveform corresponding to the energization pattern. Since such a rectangular waveform voltage includes many harmonic components, it causes noise and vibration of the motor.

As a control method for solving the above problem, a so-called "vector control method" is known, in which a sine-wave voltage is generated using a high-resolution rotational position sensor such as an optical encoder and a resolver. However, such sensors with high resolution are costly. In addition, vector control requires the use of a microcomputer with high computing power due to the large amount of computation, which may also increase the cost of hardware.

The present invention has been made to solve such problems, and its object is to provide a motor drive that can suppress harmonic components at low cost without using a high-resolution sensor or a microcomputer with high computing power. to provide the equipment.

A motor drive device according to the present invention drives a motor. The motor driving device includes a driving machine and a control device. The driver drives the motor. The control device controls the driving machine based on the output command of the shape of the specific wave. The shape of the specific wave is a rectangular wave having one or more concave portions between the rising portion and the falling portion.

According to the present invention, it is possible to provide a motor drive device capable of suppressing harmonic components at low cost without using a high-resolution sensor, a high-performance microcomputer, or the like.

3 is a functional block diagram of an electric oil pump 90; FIG. 1 is an overall configuration diagram of a motor drive device; FIG. It is a functional block diagram of a controller. 4 is a waveform diagram of an output signal of a hall sensor; FIG. It is a figure which shows an example, such as a synthetic wave. It is a figure which shows an example of a specific wave. It is an example of a map that defines U-phase correction coefficients. It is a figure which shows an example of a correction coefficient map. FIG. 4 is a waveform diagram showing a voltage command having a specific waveform after correction; It is a figure for demonstrating the method of detecting the phase every 10 degrees. 4 is a flow chart showing an example of a processing procedure of a controller; 1 is a perspective external view of an electric oil pump of the present disclosure; FIG. 1 is a cross-sectional view of an electric oil pump of the present disclosure; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.

[Functional block diagram of electric pump device]
FIG. 1 is a functional block diagram of an electric oil pump 90, which is an example of an electric pump device according to the present embodiment. In the example of FIG. 1, the electric oil pump 90 includes a motor drive device 1 and a pump section 15 for sucking up a substance and delivering the substance. The motor driving device 1 has a motor 40 and a controller 50 for controlling the motor 40, as shown in FIG. 2 which will be described later. The pump section 15 is driven by this motor 40 .

[Overall Configuration of Motor Drive Device]
FIG. 2 is an overall configuration diagram of a motor drive device according to an embodiment of the present invention. The motor driving device 1 controls an N-phase motor 40 . In this embodiment, N=3. That is, the motor 40 has three-phase windings (also called coils). In other words, the motor 40 has coils for each phase. Specifically, motor 40 has a U-phase coil, a V-phase coil, and a W-phase coil.

Referring to FIG. 2 , motor drive device 1 includes DC power supply 10 , capacitor 20 , inverter 30 , controller 50 , and hall sensors 62 , 64 , 66 . The inverter 30 corresponds to the "driving machine" of the present disclosure.

DC power supply 10 supplies DC power to inverter 30 . DC power supply 10 is, for example, an electric power storage element that stores electric power, and includes an electric storage element such as a secondary battery or an electric double layer capacitor. Capacitor 20 is connected between a pair of power lines on the DC side of inverter 30 and reduces noise on the DC side (input side) of inverter 30 .

Inverter 30 includes switching elements Sw1-Sw6. A diode is connected in antiparallel to each of the switching elements Sw1 to Sw6. The switching elements Sw1 and Sw2 constitute a U-phase upper arm and a U-phase lower arm, respectively. The switching elements Sw3 and Sw4 constitute a V-phase upper arm and a V-phase lower arm, respectively. The switching elements Sw5 and Sw6 constitute a W-phase upper arm and a W-phase lower arm, respectively.

A connection node of the switching elements Sw1 and Sw2 is connected to the U-phase coil of the motor 40. FIG. A connection node of the switching elements Sw3 and Sw4 is connected to the V-phase coil of the motor 40, and a connection node of the switching elements Sw5 and Sw6 is connected to the W-phase coil of the motor 40 (each phase coil is not shown). figure).

Inverter 30 receives DC power from DC power supply 10 and drives motor 40 based on gate signals G 1 to G 6 received from controller 50 . More specifically, switching elements Sw1-Sw6 are turned on/off based on gate signals G1-G6, and voltage is applied from inverter 30 to each phase coil of motor 40, thereby driving motor 40. FIG. A gate signal corresponds to the "output command" of the present disclosure.

Hereinafter, the voltage applied to the U-phase coil is also referred to as the "U-phase voltage", the voltage applied to the V-phase coil is also referred to as the "V-phase voltage", and the voltage applied to the W-phase coil is , is also referred to as “W-phase voltage”.

The motor 40 is a synchronous motor, specifically a brushless DC motor. A rotor of the motor 40 is provided with permanent magnets (not shown). Based on the rotor position detected by hall sensors 62 , 64 , 66 , inverter 30 switches the energization of the U, V, W phase coils. As a result, the direction of the combined magnetic flux generated by each phase coil is switched according to the rotor position, and the rotor rotates. The permanent magnets may be attached to the rotor either by an embedded type or by a surface type.

The Hall sensor 62 is arranged between the W-phase coil and the U-phase coil with respect to the rotation angle, the Hall sensor 64 is arranged between the U-phase coil and the V-phase coil with respect to the rotation angle, and the Hall sensor 66 is arranged between the U-phase coil and the V-phase coil with respect to the rotation angle. It is placed between the V-phase coil and the W-phase coil at the corner.

Hall sensors 62, 64 and 66 output signals Hu, Hv and Hw, respectively. Each of the signals Hu, Hv and Hw switches between H (logic high) level and L (logic low) level according to the change in the magnetic pole of the rotor as the rotor rotates. By combining the signals Hu, Hv, Hw from the Hall sensors 62, 64, 66, the rotor position of the motor 40 can be detected.

The controller 50 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and an input/output port for inputting/outputting various signals (all shown in FIG. not shown). The CPU develops a program stored in the ROM into the RAM or the like and executes it. The program stored in the ROM is a program describing the processing method of the controller 50 .

In the 120-degree energization control using Hall sensors, the energization pattern of the U-phase coil, V-phase coil, and W-phase coil of the motor is switched every 60 degrees (electrical angle) based on the output signal of the Hall sensor. The electrical angle corresponds to "rotor position of motor 40". Conventionally, a rectangular wave voltage is applied to each phase coil of a motor in accordance with an energization pattern. However, the rectangular wave contains many harmonic components and causes motor noise and vibration. The "rectangular wave" and "rectangular shape" in the present embodiment include a complete rectangular shape and a shape distorted from the rectangular shape due to occurrence of "blurring" in the rectangular shape.

Vector control is known as an inverter control method that replaces rectangular wave drive such as 120-degree conduction control. In vector control, a sine wave voltage is generated using a high-resolution rotational position sensor such as an optical encoder or resolver. This realizes smooth motor driving with low noise and low vibration. However, sensors with high resolution are generally costly. In addition, vector control requires coordinate conversion and complicated arithmetic processing, resulting in a large amount of arithmetic operations. Therefore, it is necessary to use a microcomputer or the like with high arithmetic performance, which also increases the cost.

Therefore, in motor drive device 1 according to the present embodiment, an inverter control method capable of suppressing harmonic components at low cost is adopted without using a high-resolution rotational position sensor or a microcomputer with high computing power. Specifically, in the motor drive device 1, the controller 50 uses Hall sensors 62, 64, and 66 to detect the electrical angle of the motor 40 every 60 degrees. Further, the controller 50 generates an output pattern of the inverter 30 for every 60 electrical degrees, and generates a rectangular wave voltage command based on the output pattern.

In motor drive device 1 according to this embodiment, controller 50 multiplies the generated rectangular-wave voltage command by a correction coefficient prepared in advance, thereby converting the rectangular-wave voltage command to a specific wave-like voltage described later. Correct to the directive. As will be described later, in the specific waveform voltage command, since harmonic components are removed to some extent, noise caused by harmonics can be reduced. Then, the controller 50 generates the gate signals G1 to G6 for the inverter 30 based on the voltage command corrected to have a specific waveform, and outputs the gate signals G1 to G6 to the inverter 30. FIG.

In this manner, in the motor driving device 1, a specific wave voltage command is generated based on rectangular wave control using the Hall sensors 62, 64, and 66 without using vector control, and the motor 40 is driven. . The configuration of the controller 50 that implements these functions will be described in detail below.

FIG. 3 is a functional block diagram showing the configuration of the speed control portion of the controller 50 shown in FIG. Referring to FIG. 3 , controller 50 includes signal switching detection portion 110 , time calculation portion 111 , output pattern generation portion 112 , speed detection portion 114 , subtraction portion 116 and speed control portion 118 . Controller 50 further includes a voltage command generation unit 120 , a correction unit 122 , a storage unit 123 and a gate signal generation unit 124 .

The signal switching detection unit 110 receives the output signals Hu, Hv, and Hw of the Hall sensors 62, 64, and 66, and detects H/L level switching of each signal. The rotor position of the motor 40 can be detected by detecting the switching of each of the signals Hu, Hv, and Hw.

FIG. 4 is a waveform diagram of the output signals Hu, Hv, Hw of the Hall sensors 62, 64, 66. FIG. Referring to FIG. 4, signal Hu switches from the H level to the L level at time t1 and switches from the L level to the H level at time t4 in accordance with the rotation of the rotor of motor 40. FIG. Thereafter, signal Hu switches from the H level to the L level again at time t7.

The signal levels of the signals Hv and Hw are also switched according to the rotation of the rotor of the motor 40 in the same manner as the signal Hu. Since the three Hall sensors 62, 64, and 66 are arranged every 120 electrical degrees, the switching timing of any one of the signals Hu, Hv, and Hw is every 60 electrical degrees. By combining the signals Hu, Hv and Hw of the hall sensors 62, 64 and 66 in this manner, the electrical angle of the motor 40 is detected every 60 degrees. In the following, 60 degrees is also referred to as "first angle". Further, in the present disclosure, a value obtained by dividing 360 degrees by the first angle is also referred to as "resolution value L". That is, the resolution value L is a value determined based on the first angle. In this embodiment, the resolution value L is six.

A value obtained by dividing 360 degrees by the resolution value L may be used as the "first angle". In this case, the first angle is a value determined based on the resolution value L. Further, in the case of a configuration having Hall sensors, as in the motor drive device 1 of the present embodiment, the resolution value L may be determined based on the number N of phases. For example, the resolution value L is a value that is twice the number N of phases.

In some motor driving devices, the resolution value L is not determined based on the number N of phases. This motor driving device is, for example, a device that drives a motor sensorlessly. In such a motor driving device, the resolution value is determined based on the first angle.

Referring to FIG. 3 again, output pattern generation unit 112 receives switching timings of signals Hu, Hv, and Hw of hall sensors 62, 64, and 66 from signal switching detection unit 110, and outputs inverter signals according to the switching timings. Generate 30 output patterns. Specifically, the output pattern generator 112 repeatedly generates six patterns PT1 to PT6 that switch according to the switching timings of the signals Hu, Hv, and Hw.

FIG. 4 is a diagram showing an example of switching timings of the signals Hu, Hv, and Hw. The output pattern generator 112, for example, sets the times t1 to t2, t2 to t3, t3 to t4, t4 to t5, t5 to t6, and t6 to t7 in FIG. 4 as patterns PT1 to PT6, respectively. Times t7-t8 and t8-t9 are patterns PT1 and PT2 again, respectively. As will be described later, voltage command generator 120 generates a rectangular wave voltage command based on this output pattern.

The speed detection unit 114 receives switching timings of the signals Hu, Hv, and Hw of the Hall sensors 62, 64, and 66 from the signal switching detection unit 110, and detects the rotation speed of the motor 40 using the switching timings. That is, since the interval between adjacent switching timings of the signals Hu, Hv, and Hw is every 60 electrical degrees, by measuring the intervals between the switching timings of the signals Hu, Hv, and Hw, the motor 40 can detect the rotation speed of As an example, when the motor 40 is a two-pole motor, the speed detection unit 114 measures the intervals of six consecutive switching timings (corresponding to one rotation of the rotor), and divides 2π by the measured time (seconds). Calculate the rotational speed (rad/sec).

Subtraction unit 116 calculates a speed deviation by subtracting the speed detection value received from speed detection unit 114 from the speed command value for motor 40 received from a higher-level control unit (not shown). 118.

Speed control unit 118 receives as input the speed deviation received from subtraction unit 116 , performs, for example, a proportional integral calculation, and outputs the calculation result to voltage command generation unit 120 . That is, speed control unit 118 executes speed feedback (FB) control based on the deviation between the speed command value and the speed detection value.

Voltage command generation unit 120 generates a rectangular wave voltage command (hereinafter referred to as “rectangular wave voltage command”) based on the output pattern generated by output pattern generation unit 112 and the output of speed control unit 118 . do. Specifically, the voltage command generation unit 120 generates rectangular wave voltage commands in which the energization of each phase coil is switched every 180 electrical degrees and the energization patterns between the phases are shifted from each other by 120 degrees. The magnitude of the rectangular wave voltage command is adjusted according to the output of speed control section 118 .

As an actual calculation, voltage command generation unit 120 sequentially receives patterns PT1 to PT6 from output pattern generation unit 112 according to the rotation of motor 40. FIG. Voltage command generation unit 120 also receives the calculation result from speed control unit 118 . Then, the voltage command generation unit 120 generates the above-described rectangular wave voltage command in which the energization pattern is switched for each of the patterns PT1 to PT6.

The time calculation unit 111 calculates the time required for the rotor to rotate a second angle (10 degrees in the present embodiment) smaller than the first angle (hereinafter also referred to as “second time”). Calculate Specifically, the time calculation unit 111 calculates the time s required for the rotor to rotate the angle corresponding to the half cycle (that is, 180 degrees) based on Equation (5) described later. Further, the time calculation unit 111 calculates the second time based on the calculation result of Equation (5) and Equation (6) described below. Each time the time calculation unit 111 calculates the second time, the time calculation unit 111 outputs a timing signal indicating the calculation to the correction unit 122 .

The correction unit 122 converts the rectangular wave voltage command generated by the voltage command generation unit 120 into a specific wave voltage command using the timing signal from the time calculation unit 111 and a correction coefficient for correcting the rectangular wave to a specific wave. corrected to Specifically, correction coefficients for correcting rectangular waves of phases U, V, and W to specific waves are prepared in advance as a correction coefficient map (see FIG. 8 described later) and stored in the storage unit 123 . . The correction coefficient map corresponds to "command information" of the present disclosure. Storage unit 123 is configured by, for example, a ROM. Then, the correction unit 122 acquires a correction coefficient from the correction coefficient map, and multiplies the rectangular wave voltage command generated by the voltage command generation unit 120 by the correction coefficient, thereby obtaining a rectangular wave of each of the U, V, and W phases. Corrects the voltage command to a specific waveform voltage command.

[About specific waves]
Next, the specific wave will be explained. The inventors discovered that if the specific wave has a waveform similar to the following composite wave, harmonic components can be reduced to some extent. The composite wave of this embodiment is generated by combining a sine wave, a third harmonic, and a ninth harmonic.

FIG. 5 is a diagram showing an example of a composite wave and the like. In FIG. 5, horizontal lines indicate phases, and vertical lines indicate amplitudes (voltages). In FIG. 5, the composite wave is indicated by a solid line, the 3rd harmonic is indicated by a dashed line, the 9th harmonic is indicated by a dashed line, and the sine wave (fundamental wave) is indicated by a dashed line. As shown in FIG. 5, a composite wave is generated by combining the sine wave, the third harmonic, and the ninth harmonic.

Also, in the example of FIG. 5, there are two minimum values in the range of 0 degrees<θ≦180 degrees. In the example of FIG. 5, these two minima are referred to as the first minima A1 and the second minima A2. Also, in the example of FIG. 5, there are two maximum values in the range of 180 degrees<θ≦360 degrees. In the example of FIG. 5, these two local minima are called the first local maximum A3 and the second local maximum A4.

FIG. 6 is a diagram showing an example of a specific wave according to this embodiment. FIG. 6 is an example of a specific wave corresponding to the U-phase voltage. In the example of FIG. 6, the specific wave is a rectangular wave K having two concave portions between the rising portion M1 and the falling portion M2. Note that the voltage command for the rectangular wave K is generated by the voltage command generation unit 120 .

In the example of FIG. 6, there are a first recess B1 and a second recess B2 between the rising portion M1 of the rectangular wave K and the falling portion M2 of the rectangular wave K in the range of 0 degrees<θ≦180 degrees. Further, in the range of 180 degrees<θ≦360 degrees, there are a third concave portion B3 and a fourth concave portion B4 between the falling portion M2 of the rectangular wave K and the rising portion M1 of the rectangular wave K.

Also, in the example of FIG. 6, the first concave portion B1 is a concave portion formed by falling at θ=40 degrees and rising at θ=50 degrees. The second concave portion B2 is a concave portion formed by falling at θ=70 degrees and rising at θ=80 degrees. The third recess B3 is a recess formed by rising at θ=220 degrees and falling at θ=230 degrees. The fourth recess B4 is a recess formed by rising at θ=250 degrees and falling at θ=260 degrees.

Also, the first concave portion B1 corresponds to the first minimum value A1 (see FIG. 5). The second recess B2 corresponds to the second minimum value A2. The third recess B3 corresponds to the first local maximum A3. The fourth recess B4 corresponds to the second maximum value A4.

A direction orthogonal to the phase direction (the X-axis direction in FIG. 6) is the Y-axis direction in FIG. Two waveforms are defined by dividing the specific wave K in two by a straight line L in the Y-axis direction. These two waveforms are referred to as the first specific wave K1 and the second specific wave K2. The first specific wave K1 has a first concave portion B1. The second specific wave K2 has a second concave portion B2. Also, although not shown in FIG. 6, the other specific wave is also composed of a first specific wave and a second specific wave, the first specific wave having a concave portion and the second specific wave having a concave portion. For example, specific waves from 180 degrees to 300 degrees are also divided into first specific waves and second specific waves. The first specific wave has a third recess B3, and the second specific wave has a fourth recess B4. Also, the shape of the specific wave shown in FIG. 6 is the same for the V phase and the W phase (see FIG. 9).

In addition, in the sine wave of FIG. 5, the phase at which the voltage value peaks is 90 degrees. This phase (90 degrees) is the midpoint phase in the phase range (that is, 0 degrees to 180 degrees) in which the voltage value is positive. On the other hand, in the specific wave of FIG. 6, the phase at the middle point in the phase range (that is, 0 degrees to 120 degrees) in which the voltage value is positive is 60 degrees. That is, the specific wave in FIG. 6 lags behind the sine wave (composite wave) in FIG. 5 by 30 degrees.

FIG. 7 is an example of a map that defines U-phase correction coefficients. The correction unit 122 can correct the rectangular wave voltage command to the specific wave voltage command as shown in FIG. 6 by multiplying the rectangular wave voltage command by the correction coefficient defined in the map shown in FIG. Each numerical value in FIG. 7 will be described later with reference to FIG.

Next, the reason why it is preferable to apply a composite wave of a sine wave, a triple harmonic wave, and a ninth harmonic wave will be described. As described above, the rectangular waveform voltage contains many harmonic components, which causes motor noise and vibration. Here, the result shown in the following equation (1) is obtained by executing the Fourier transform on the rectangular wave f(x).

As is clear from this equation (1), the rectangular wave f(x) includes 1st harmonic (sine wave), 3rd harmonic, 5th harmonic, 7th harmonic, and (2m -1) consists of double harmonics. However, m is an arbitrary natural number. The denominator of the coefficient of each term in the braces in this equation (1) is "a coefficient obtained by executing a Fourier transform on a rectangular wave". The coefficients are also multiples of the harmonics that make up the square wave f(x). Then, the coefficients are 1, 3, 5, 7, 9, and so on. That is, this coefficient is an odd number.

Next, it will be explained that the 3n-fold harmonics of the U-phase voltage, V-phase voltage, and W-phase voltage are at the same potential. However, n is an arbitrary natural number. When the harmonics of the U-phase voltage, the V-phase voltage, and the W-phase voltage have the same potential, noise, vibration, etc. of the motor 40 can be reduced. 3n-fold harmonics of the U-phase voltage, the V-phase voltage, and the W-phase voltage are referred to as Vu3n, Vv3n, and Vw3n, respectively. Further, in Vu3n, Vv3n, and Vw3n, the following equations (2) to (4) are obtained by adjusting the phase scale to the 3nth harmonic and using complex numbers.
Vu3n=V·êj(0) (2)
Vu3n=V·e^j(2π/3)×3n)
=V·e^j(2nπ) (3)
Vw3n=V·êj(4π/3)×3n)
=V·e^j(4nπ) (4)
However, in the above formulas (2) to (4), V represents the voltage value of the rectangular wave, e represents the natural logarithm, "^" represents the power, j represents the imaginary number, and n is any natural number. indicates As shown in the above equations (2) to (4), Vu3n=Vu3n=Vw3n. Therefore, the 3nth harmonic of the U-phase voltage, the V-phase voltage, and the W-phase voltage have the same potential. That is, in the U-phase voltage, the V-phase voltage, and the W-phase voltage, harmonics of multiples of 3 have the same potential. Note that the value related to the multiple (that is, 3) corresponds to half the phase number and the resolution value of the motor. In the present embodiment, since the number of phases of the motor 40 is "3", the value related to the multiple is also "3". Therefore, the harmonic coefficient is a multiple of 3 (a multiple of the number of phases of the motor 40).

Then, the harmonics of the multiples in each of the values common to the above-mentioned Fourier transform coefficients (that is, odd numbers) and the multiples of 3 (the number of phases of the motor) can properly control the motor 40, and the Noise and vibration can be reduced. Values common to odd numbers and multiples of 3 are 3, 9, 15, 21, and so on. In view of these common values, the inventors believe that a composite wave of a sine wave, a triple harmonic wave, and a ninth harmonic wave can appropriately control the motor 40 and reduce noise and vibration of the motor 40. discovered. From the above, it is preferable to apply a composite wave of a sine wave, a third harmonic, and a ninth harmonic.

FIG. 8 is a diagram showing an example of the correction coefficient map described above. In FIG. 8, a U-phase correction coefficient, a V-phase correction coefficient, and a W-phase correction coefficient are defined. In this correction coefficient map, a correction coefficient for the output command is defined for the second angle. Note that the correction coefficients defined in this correction coefficient map are examples.

It is specified that the U-phase correction coefficient is 1, the V-phase correction coefficient is −1, and the W-phase correction coefficient is 0 for a phase of 0 degrees. It is specified that the U-phase correction coefficient is 1, the V-phase correction coefficient is −0.9, and the W-phase correction coefficient is 0 for a phase of 10 degrees. It is specified that the U-phase correction coefficient is 1, the V-phase correction coefficient is −1, and the W-phase correction coefficient is 0 for a phase of 20 degrees.

It is specified that the U-phase correction coefficient is 0.9, the V-phase correction coefficient is −1, and the W-phase correction coefficient is 0 for a phase of 40 degrees. It is specified that the U-phase correction coefficient is 1, the V-phase correction coefficient is −1, and the W-phase correction coefficient is 0 for a phase of 50 degrees. For a phase of 60 degrees, it is specified that the U-phase correction coefficient is 1, the V-phase correction coefficient is 0, and the W-phase correction coefficient is −1.

For a phase of 70 degrees, the U-phase correction coefficient is 0.9, the V-phase correction coefficient is 0, and the W-phase correction coefficient is −1. For a phase of 80 degrees, it is specified that the U-phase correction coefficient is 1, the V-phase correction coefficient is 0, and the W-phase correction coefficient is −1. For a phase of 100 degrees, the U-phase correction coefficient is 1, the V-phase correction coefficient is 0, and the W-phase correction coefficient is −0.9.

For a phase of 110 degrees, it is specified that the U-phase correction coefficient is 1, the V-phase correction coefficient is 0, and the W-phase correction coefficient is −1. It is specified that the U-phase correction coefficient is 0, the V-phase correction coefficient is 1, and the W-phase correction coefficient is −1 for a phase of 120 degrees. For a phase of 130 degrees, the U-phase correction coefficient is 0, the V-phase correction coefficient is 1, and the W-phase correction coefficient is −0.9.

It is specified that the U-phase correction coefficient is 0, the V-phase correction coefficient is 1, and the W-phase correction coefficient is −1 for a phase of 140 degrees. For a phase of 160 degrees, it is specified that the U-phase correction coefficient is 0, the V-phase correction coefficient is 0.9, and the W-phase correction coefficient is −1. It is specified that the U-phase correction coefficient is 0, the V-phase correction coefficient is 1, and the W-phase correction coefficient is −1 for a phase of 170 degrees.

It is specified that the U-phase correction coefficient is -1, the V-phase correction coefficient is 1, and the W-phase correction coefficient is 0 for a phase of 180 degrees. It is specified that the U-phase correction coefficient is -1, the V-phase correction coefficient is 0.9, and the W-phase correction coefficient is 0 for a phase of 190 degrees. It is specified that the U-phase correction coefficient is -1, the V-phase correction coefficient is 1, and the W-phase correction coefficient is 0 for a phase of 200 degrees.

It is specified that the U-phase correction coefficient is -0.9, the V-phase correction coefficient is 1, and the W-phase correction coefficient is 0 for a phase of 220 degrees. It is specified that the U-phase correction coefficient is -1, the V-phase correction coefficient is 1, and the W-phase correction coefficient is 0 for a phase of 230 degrees. It is specified that the U-phase correction coefficient is -1, the V-phase correction coefficient is 0, and the W-phase correction coefficient is 1 for a phase of 240 degrees.

It is specified that the U-phase correction coefficient is -0.9, the V-phase correction coefficient is 0, and the W-phase correction coefficient is 1 for a phase of 250 degrees. It is specified that the U-phase correction coefficient is −1, the V-phase correction coefficient is 0, and the W-phase correction coefficient is 1 for a phase of 260 degrees. For a phase of 280 degrees, the U-phase correction coefficient is −1, the V-phase correction coefficient is 0, and the W-phase correction coefficient is 0.9.

It is specified that the U-phase correction coefficient is -1, the V-phase correction coefficient is 0, and the W-phase correction coefficient is 1 for a phase of 290 degrees. It is specified that the U-phase correction coefficient is 0, the V-phase correction coefficient is −1, and the W-phase correction coefficient is 1 for a phase of 300 degrees. For a phase of 310 degrees, it is specified that the U-phase correction coefficient is 0, the V-phase correction coefficient is −1, and the W-phase correction coefficient is 0.9.

It is specified that the U-phase correction coefficient is 0, the V-phase correction coefficient is −1, and the W-phase correction coefficient is 1 for a phase of 320 degrees. It is specified that the U-phase correction coefficient is 0, the V-phase correction coefficient is −0.9, and the W-phase correction coefficient is 1 for a phase of 340 degrees. It is specified that the U-phase correction coefficient is 0, the V-phase correction coefficient is −1, and the W-phase correction coefficient is 1 for a phase of 350 degrees.

Note that the 360-degree phase correction coefficient is the same as the 0-degree phase correction coefficient. The map shown in FIG. 7 is a map obtained by extracting the U-phase correction coefficient from the map shown in FIG.

FIG. 9 is a waveform diagram showing a voltage command having a specific waveform after correction by correction section 122 using the map shown in FIG. FIG. 9 shows a U-phase applied voltage, a V-phase applied voltage, and a W-phase applied voltage. The horizontal axis of FIG. 9 indicates the phase, and the vertical axis indicates the voltage value. The positive waveform of the U-phase applied voltage in FIG. 9 indicates the voltage applied to the U-phase coil in the positive direction, and the negative waveform of the U-phase applied voltage in FIG. 9 indicates the voltage applied to the U-phase coil in the negative direction. indicates the voltage applied. The positive waveform of the V-phase applied voltage in FIG. 9 indicates the voltage applied to the V-phase coil in the positive direction, and the negative waveform of the V-phase applied voltage in FIG. 9 indicates the voltage applied to the V-phase coil in the negative direction. indicates the voltage applied. The positive waveform of the W-phase applied voltage in FIG. 9 indicates the voltage applied to the W-phase coil in the positive direction, and the negative waveform of the W-phase applied voltage in FIG. 9 indicates the voltage applied to the W-phase coil in the negative direction. indicates the voltage applied. Further, V is the maximum value of the voltage value in the positive direction of the voltage command before correction (that is, the voltage command of the rectangular wave).

Each waveform of the U-phase applied voltage, the V-phase applied voltage, and the W-phase applied voltage shown in FIG. 9 has a shape corresponding to the correction coefficient of the map shown in FIG. For example, when the phase is 40 degrees, the U-phase applied voltage is 0.9V because the U-phase correction coefficient is 0.9. Since the V-phase correction coefficient is -1, the U-phase applied voltage is -V. Also, since the W-phase correction coefficient is 0, the U-phase applied voltage is 0.

It should be noted that the correction coefficients defined in FIG. 8 may be different numerical values so as to obtain the effect of the motor drive device 1 of the present embodiment. For example, the correction coefficient of 0.9 may be changed to 0.8.

Further, as described above, the controller 50 can detect the electrical angle (phase at 60 degrees) every 60 degrees, which is the first angle. Furthermore, the controller 50 detects the phase for each angle (10 degrees) smaller than the first angle. The controller 50 can identify the phase defined in the map of FIG. 8 by this detection.

FIG. 10 is a diagram for explaining a method of detecting a phase every 10 degrees. In FIG. 10, it is assumed that the controller 50 detects a phase of 60 degrees, which is the first angle. When this 60-degree phase is detected, the controller 50 calculates the time s required for the rotor to rotate the angle corresponding to the half cycle (that is, 180 degrees). The controller 50 calculates the time s by, for example, the following formula (5).

s=60/(q×p/2) (5)
Here, q indicates the rotational speed and p indicates the number of poles. A speed detector 114 acquires the rotation speed q. Also, the pole number p is stored in the storage unit 123 in advance.

Since the time s is the time required for the rotor to rotate 180 degrees, the controller 50 divides the time s by 18, as shown in the following equation (6), so that the rotor rotates 10 degrees. It is possible to calculate the time t required to rotate by degrees.

t=s/18 (6)
The controller 50 can detect the phase every 10 degrees (electrical angle every 10 degrees) as the rotor position of the motor 40 based on the time t. For example, in the example of FIG. 10, the controller 50 calculates the time t based on the above equations (5) and (6) at the timing of detecting 60 degrees. Then, when the controller 50 detects that the time t has passed since the timing of detecting 60 degrees, it detects a phase of 70 degrees in a pseudo manner. Further, when the controller 50 detects that the time 2t has passed since the timing of detecting 60 degrees, it detects the phase of 80 degrees in a pseudo manner. When the controller 50 detects that time 4t has passed since the timing of detecting 60 degrees, it detects a phase of 100 degrees in a pseudo manner. Further, when the controller 50 detects that the time 5t has passed since the timing of detecting 60 degrees, the controller 50 detects a phase of 110 degrees in a pseudo manner.

Further, when the controller 50 detects the angle (that is, 120 degrees) corresponding to the next first angle, the controller 50 newly sets the time s and the time t based on the above formula (5) or (6). Calculate

Thus, the controller 50 can detect the rotor position for each second angle (10 degrees) smaller than the first angle (60 degrees), which is the standard resolution, by using equations (5) and (6). That is, the controller 50 can set the rotor position angles to 0, 10, 20, 30, 40, 50, 60, . . . , 350 degrees, and 360 degrees (hereinafter referred to as the "whole angle group") can be detected. Note that 0, 60, 120, 180, 240, and 300 degrees in the entire angle group are the first angles, but are also the second angles. That is, the correction coefficient map is a map in which correction coefficients for output commands are defined for the second angle.

[Controller flow chart]
FIG. 11 is a flow chart showing an example of a processing procedure executed by the controller 50. As shown in FIG. When the processing of the motor driving device 1 is started, the controller 50 starts the processing of FIG. 11 .

First, in step S2, the controller 50 determines whether or not the current first angle has been detected as the electrical angle. In step S2, the controller 50 waits until the current first angle is detected as the electrical angle (NO in step S2). As described above, the controller 50 detects the current first angle based on the switching timing of any one of the signals Hu, Hv, and Hw.

When the current first angle is detected in step S2, the controller 50 outputs a gate signal corresponding to the current first angle in step S4. For example, when 60 degrees is detected as the first angle of this time, the controller 50 outputs a gate signal reflecting the correction coefficient of each phase specified for the phase of 60 degrees shown in FIG. .

Next, in step S6, time s and time t are calculated based on the above equations (5) and (6). Next, in step S8, the controller 50 determines whether or not the second angle is detected based on the time t (see description of FIG. 10). In step S8, the controller 50 waits until the second angle is detected (NO in step S8). When the second angle is detected, the controller 50 outputs a gate signal corresponding to the second angle (current second angle) in step S10. For example, when 70 degrees is detected as the second angle this time, the controller 50 outputs a gate signal reflecting the correction coefficient of each phase specified for the phase of 70 degrees shown in FIG. .

Next, in step S12, the controller 50 determines whether or not the gate signals for all four second angles from the first angle to the next first angle have been output. In the example of FIG. 10, if the current first angle is 60 degrees and the next first angle is 120 degrees, the four second angles are 70 degrees, 80 degrees, 100 degrees, and 110 degrees. Become.

If it is determined NO in step S12, that is, if it is determined that the gate signals for all the four second angles have not been output, the process returns to step S8. If YES is determined in step S12, the process returns to step S2.

[Configuration example of electric pump device]
The configuration of the aforementioned electric oil pump 90 will be described in detail. FIG. 12 is a perspective external view of an electric oil pump 901 that is an example of the electric oil pump 90. As shown in FIG. FIG. 13 is a cross-sectional view of electric oil pump 901 taken along line XX in FIG. The electric oil pump 901 described below corresponds to a specific example of the electric oil pump 90, the pump section 902 corresponds to the pump section 15, the motor section 903 corresponds to the motor 40, and the controller 904 corresponds to the controller 50, respectively. .

The electric oil pump 901 according to the present disclosure is an electric oil pump that mainly supplies hydraulic pressure to the transmission while the engine is stopped. An electric oil pump 901 sucks oil from an oil reservoir at the bottom of the transmission case, discharges the oil, and pumps the oil into the transmission, thereby ensuring the necessary oil pressure and lubricating oil amount in the transmission.

As shown in FIG. 13, an electric oil pump 901 according to the present disclosure includes a pump unit 902 that generates hydraulic pressure, a motor unit 903 that drives the pump unit 902, and a controller provided with a control circuit that controls the motor unit 903. 904 (main board), and a housing 905 that accommodates a pump section 902 , a motor section 903 and a controller 904 . Each member or element will be described in detail below.

In the following description, the direction parallel to the axis O of the motor unit 903 is called the "axial direction", and the radial direction of a circle centered on the axis O is called the "radial direction" (the "inner diameter direction" and the "radial direction"). "Outer diameter" also means the inner and outer diameters of the circle). Also, the circumferential direction of a circle centered on the axis O is called the “circumferential direction”.

As shown in FIG. 13, the pump portion 902 according to the present disclosure is a rotary pump that pumps oil by rotating. Specifically, the pump unit 902 includes an inner rotor 921 having a plurality of external teeth, an outer rotor 922 having a plurality of internal teeth, and a pump case 923 as a stationary member that houses the inner rotor 921 and the outer rotor 922. A trocolloid pump with An inner rotor 921 is arranged on the inner diameter side of the outer rotor 922 . The outer rotor 922 is located eccentrically with respect to the inner rotor 921 . Some of the teeth of the outer rotor 922 mesh with some of the teeth of the inner rotor 921 . If the number of teeth of the inner rotor 921 is n, the number of teeth of the outer rotor 922 is (n+1). Both the outer peripheral surface of the outer rotor 922 and the inner peripheral surface of the pump case 923 are cylindrical surfaces that can be fitted to each other. The outer rotor 922 is rotatably arranged on the inner circumference of the pump case 923 so as to be driven to rotate with the rotation of the inner rotor 921 .

As shown in FIG. 13, the motor section 903 is arranged axially side by side with the pump section 902 . A three-phase brushless DC motor, for example, is used as the motor unit 903 . The motor section 903 has a stator 930 having a plurality of coils 930 a , a rotor 931 arranged inside the stator 930 with a gap therebetween, and an output shaft 932 coupled to the rotor 931 . The stator 930 is formed with coils 930a corresponding to three phases of U-phase, V-phase and W-phase.

The output shaft 932 is rotatably supported with respect to the housing 905 via bearings 933 and 934 . The inner rotor 921 of the pump section 902 is attached to the end of the output shaft 932 on the pump section 902 side. No speed reducer is arranged between the output shaft 932 and the pump section 902, and the inner rotor 921 is fitted to the output shaft 932 of the motor section 903 so that power can be transmitted by, for example, the width across flats. A seal 935 having a seal lip in sliding contact with the outer peripheral surface of the output shaft 932 is arranged between the inner rotor 921 and the bearing 933 located on the pump portion 902 side in the axial direction. This seal 935 prevents oil from leaking from the pump section 902 to the motor section 903 . An axially compressed elastic member 936 is arranged between the bearing 933 and the seal 935 on the side of the pump portion 902 in the axial direction to apply preload to the bearings 933 and 934 .

A detector 937 is provided between the rotating side and the stationary side of the motor section 903 to detect the rotation angle of the rotor 931 in the motor section 903 . The detection unit 937 according to the present disclosure includes a sensor magnet 937a (e.g., a neodymium bond magnet) attached via a bracket 938 to the shaft end of the output shaft 932 on the side opposite to the pump unit, and a housing 905 provided on the stationary side. It can be configured with a magnetic sensor 937b such as an MR element. The magnetic sensor 937 b is attached to a sub-board 939 arranged opposite to the shaft end of the output shaft 932 opposite to the pump and arranged in a direction orthogonal to the output shaft 932 . A detected value of the magnetic sensor 937b is input to a control circuit of the controller 904 (main board), which will be described later.

A Hall element can also be used as the magnetic sensor 937b. In addition to the magnetic sensor, an optical encoder, resolver, or the like can also be used as the detection unit 937 . Note that the motor unit 903 can also be driven sensorless.

The controller 904 according to the present disclosure is arranged parallel to the output shaft 932 of the motor section 903 . A plurality of electronic components 941 are mounted on the controller 904 . These electronic components 941 constitute a control circuit for controlling the driving of the motor section 903 . In the illustrated example, the controller 904 is arranged with a surface (mounting surface) 940 on which electronic components 941 are mounted facing the pump section 902 and the motor section 903 . Controller 904 is powered by an external power source through connector 942 .

The housing 905 includes a cylindrical housing body 950 with both ends open, a first lid portion 951 that closes the opening on the pump side in the axial direction of the housing body 950, and an opening on the side opposite to the pump in the axial direction of the housing body 950. and a second lid portion 952 that closes the . The first lid portion 951 and the second lid portion 952 are fixed to the housing body 950 using a plurality of fastening bolts B1 and B2, respectively.

The second lid portion 952 has a cylindrical bearing case 952a that supports the anti-pump side bearing 934, and a cover 952b that closes the anti-pump side opening of the bearing case 952a. A sub-board 939 is arranged on the inner diameter side of the bearing case 952a. The cover 952b is attached to the bearing case 952a using a fastening member (not shown).

The housing body 950 has a pump accommodating portion 953 that accommodates the pump portion 902 , a motor accommodating portion 954 that accommodates the motor portion 903 , and a controller accommodating portion 955 that accommodates the controller 904 . The housing body 950 is integrally formed in one piece, for example by casting, cutting, or a combination thereof. The housing main body 950, the first lid portion 951, and the second lid portion 952 are made of a metal material that is a conductor and has good thermal conductivity, such as an aluminum alloy. Alternatively, one or more of the housing main body 950, the first lid portion 951, and the second lid portion 952 may be made of other metal material (for example, ferrous metal) or resin.

The pump housing portion 953 of the housing 905 has a generally cylindrical shape including the pump case 923 of the pump portion 902 . A pump chamber 966 in which the inner rotor 921 and the outer rotor 922 are accommodated, a suction port 962 and a discharge port 964 are formed in the pump accommodating portion 953 . The suction port 962 and the discharge port 964 are both provided adjacent to the motor section 903 side (left side in FIG. 13) of the pump chamber 966 and open to the meshing portion of the inner rotor 921 and the outer rotor 922 . The suction port 962 and the discharge port 964 both form an arcuate shape extending in the circumferential direction of the output shaft 932 and are provided at positions opposed to each other by 180° in the circumferential direction.

A motor accommodating portion 954 of the housing 905 is formed in a cylindrical shape. A stator 930 of the motor portion 903 is press-fitted or adhesively fixed to the cylindrical inner peripheral surface of the motor accommodating portion 954 . A controller accommodating portion 955 of the housing 905 is open on the radially outer side (lower side in FIG. 13), and after the controller 904 is accommodated in the inner circumference, the opening is closed by a cover 957 . Cover 957 is attached to housing body 950 using fastening member B3.

As shown in FIGS. 12 and 13, flange-like mounting portions 958 and 959 for mounting the electric oil pump 901 to a mounting target component (a transmission case in the present disclosure) are integrally provided on both axial sides of the housing body 950. It is formed. Two fastening holes 958a are formed in the mounting portion 958 on the pump portion 902 side, and two fastening holes 959a are formed in the mounting portion 959 on the anti-pump portion side. By inserting a fastening member (not shown) into these fastening holes 958a and 959a and screwing the fastening member into the transmission case, the electric oil pump 901 is attached to the transmission case.

As shown in FIG. 13, the housing body 950 is provided with a suction line 960 through which oil supplied to the pump portion 902 flows, and a discharge line 961 through which oil discharged from the pump portion 902 flows. One end of suction conduit 960 is connected to suction port 962 . The other end of the suction conduit 960 opens to the surface of the housing body 950 , and this opening serves as a suction port 963 . One end of the discharge conduit 961 is connected to the discharge port 964 . The other end of the discharge conduit 961 opens to the surface of the housing body 950 , and this opening serves as a discharge port 965 . The intake port 963 and the discharge port 965 are provided on the surface of the housing 905 facing the transmission case. As a result, there is no need to route an oil pipe around the electric oil pump 901, and the peripheral structure of the electric oil pump 901 can be simplified.

Further, in the electric oil pump 901 described above, the suction port 963 and the discharge port 965 are provided on the surface of the housing body 950 . In addition, a suction pipe line 960 that connects the suction port 963 and the pump section 902 and a discharge pipe line 961 that connects the discharge port 965 and the pump section 902 are both provided in the housing body 950 . Therefore, the housing main body 950 can be cooled by the oil flowing through the suction pipe 960 and the discharge pipe 961 . This cooling effect can promote cooling of the motor unit 903 and the controller 904 that serve as heat sources, and the reliability of the electric oil pump 901 can be enhanced. In addition, compared to the case where the suction pipe 960 and the discharge pipe 961 are provided in a member separate from the housing main body 950, the size of the electric oil pump 901 can be reduced.

It is also possible to use the suction line 960 as the discharge line and the discharge line 961 as the suction line without changing the structures of the suction line 960 and the discharge line 961 . Both the suction pipe 960 and the discharge pipe 961 are arranged in the region between the pump section 902 and the motor section 903 in the axial direction, and one of them is arranged in another region (for example, the outer diameter side region of the motor section 903). ) can also be placed in

In the present embodiment, an electric oil pump for an automatic transmission is used as an example of an electric pump, but an electric pump for other purposes may be used as long as it is an electric pump.

As described above, the controller 50 controls the inverter 30 based on the specific wave shape output command. Moreover, as shown in FIGS. 6 and 9, the specific wave has two recesses (that is, the first recess B1 and the second recess B2) between the rising portion M1 and the falling portion M2 in the rectangular wave K. . Harmonic components that adversely affect the motor 40 are removed to some extent by the output command having such a specific wave shape. Therefore, in the motor drive device 1 of the present embodiment, noise, vibration, etc. of the motor 40 can be reduced without using a high-resolution sensor, a high-performance microcomputer, or the like.

The specific waves in FIGS. 6 and 9 are closer to the composite wave (see the solid line in FIG. 5) in terms of reflecting the maximum and minimum values compared to the rectangular wave. In addition, the composite wave is a multiple (3, 6, 9, 12...) and an odd number (1, 3, 5, 7, 9...) of half the resolution value of the motor (the number of phases of the motor). is generated by synthesizing harmonics and fundamental waves of multiples (that is, 3, 9, 15, 21, 27, . That is, the synthetic wave is generated by synthesizing the fundamental wave and the (6c-3) harmonic (where c is an arbitrary natural number). Specifically, the composite wave is at least one of 3rd harmonic, 9th harmonic, 15th harmonic, 21st harmonic, and (6c-3) harmonic It is generated by synthesizing two harmonics and a fundamental wave. Therefore, each of the (6c-3) harmonics has the same potential in each of the U-phase, V-phase and W-phase, so that noise, vibration and the like of motor 40 are reduced. Also, most of the input voltage to the motor 40 is a sinusoidal component, and as a result the current has a waveform close to a sinusoid. Therefore, also from this point of view, the noise and vibration of the motor 40 are reduced.

Further, experiments by the inventors have revealed that the (6c-3) harmonic is preferably the 3rd harmonic and the 9th harmonic. That is, the composite wave is preferably generated by combining the fundamental wave, the third harmonic, and the ninth harmonic. As a result, the noise and vibration of the motor 40 can be reduced more accurately.

Also, each of the first recess B1, the second recess B2, the third recess B3, and the fourth recess B4 is rectangular. With such a configuration, the controller 50 can bring the specific wave closer to the composite wave with simple voltage control.

Further, the value (for example, the voltage value) defined by the concave portion of the specific wave is the value (that is, the voltage value V) at the portion corresponding to the concave portion of the rectangular wave K multiplied by 0.9. (See 0.9 and -0.9 in Figures 7 and 8). With such a configuration, the controller 50 can bring the specific wave closer to the composite wave with simple voltage control.

Further, as shown in FIG. 6, the first specific wave K1 and the second specific wave K2 are determined by dividing the specific wave into two equal parts. The first specific wave K1 has one concave portion (first concave portion B1), and the second specific wave K2 has one concave portion (second concave portion B2). Since the specific waveform is such a waveform, the controller 50 can bring the specific wave closer to the composite wave with simple control.

The controller 50 also calculates the time corresponding to one cycle of the motor 40 based on the rotational speed q of the motor 40 and the number of poles p of the motor 40 . In this embodiment, the time s corresponding to the half cycle of the motor 40 is calculated based on the above equation (5). Then, the controller 50 calculates the time t corresponding to 10 degrees of the motor 40 using the equation (6). The controller 50 pseudo-detects the electrical angle for each second angle based on this time t. The controller 50 also holds the map shown in FIG. This map defines the correction coefficient of the output command for the second angle. Controller 50 multiplies the voltage value defined by the square wave by a correction factor consistent with the detected second angle. By this multiplication, the controller 50 can correct the square wave to the specific wave described above. Therefore, the controller 50 can correct the rectangular wave to the specific wave described above by a relatively simple calculation.

[Modification]
(1) In the above-described embodiments, as shown in FIGS. 6 and 9, one specific wave has two recesses. However, the number of recesses varies depending on the parameters of motor 40 (eg, the number of poles and phases of motor 40). For example, one specific wave may have one concave portion. Also, one specific wave may have three or more concave portions. That is, one specific wave has one or more recesses, so that the motor driving device has the same effect as described above.

(2) In the above embodiment, the controller 50 corrects the rectangular wave to generate an output command for the specific wave. However, the controller 50 may directly generate an output command for the specific wave without executing the processing for correcting the rectangular wave. In the motor driving device of this modified example, values obtained by multiplying all the correction coefficients in FIG. 8 by the voltage V are stored in the storage unit 123 as a map. In addition, the controller does not have a correction unit, and the voltage command generation unit 120 does not generate a rectangular wave output command, but generates a specific wave output command based on the modified image map. Even the motor drive device adopting such a configuration has the same effect as the above-described embodiment.

(3) The controller 50 of the present embodiment uses the Hall sensors 62, 64, 66 to detect the first angle θ1. However, the controller 50 may detect the first angle θ1 by another method. For example, the first angle θ1 may be detected by detecting an induced voltage without using a Hall sensor.

The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the description of the above-described embodiments, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

1 motor drive unit 10 DC power supply 20 capacitor 30 inverter 40 motor 50 controller 62, 64, 66 hall sensor 110 signal switching detector 111 time calculator 112 output pattern generator 114 speed detector , 116 subtraction unit, 118 speed control unit, 120 voltage command generation unit, 122 correction unit, 123 storage unit, and 124 gate signal generation unit.

Claims (8)

A motor drive device for driving a motor,
a driver for driving the motor;
a control device that controls the driving machine based on an output command of a specific wave shape,
The motor driving device, wherein the shape of the specific wave is a rectangular wave having one or more concave portions between a rising portion and a falling portion. the specific wave is a wave closer to a synthetic wave than the rectangular wave,
2. The composite wave is generated by synthesizing a harmonic wave and a fundamental wave of each of two or more odd multiples of half the resolution value of the motor. A motor drive as described. a resolution value of the motor is 6;
3. The motor drive device according to claim 2, wherein said synthetic wave is generated by synthesizing said fundamental wave, third harmonic, and ninth harmonic. 2. The motor driver of claim 1, wherein each of said one or more recesses is rectangular. The value defined by each of the one or more recesses is a value obtained by multiplying the value of the portion of the rectangular wave corresponding to the recess by 0.9. 2. The motor drive device according to item 1. the one or more recesses include a first recess and a second recess;
The specific wave is composed of a first specific wave and a second specific wave determined by halving the rising portion and the falling portion in a direction orthogonal to the phase direction,
The first specific wave has the first recess,
The motor driving device according to any one of claims 1 to 5, wherein said second specific wave has said second concave portion. The control device is
detecting a second angle smaller than a first angle determined by the number of phases of the motor as the rotor position of the motor, based on the rotation speed of the motor and the number of poles of the motor;
correcting the output command of the shape of the rectangular wave to the output command of the shape of the specific wave based on the command information that defines the correction coefficient of the output command for the second angle;
The motor driving device according to any one of claims 1 to 6, wherein the driving device is controlled based on an output command of the shape of the specific wave obtained by the correction. An electric pump device comprising the motor drive device according to any one of claims 1 to 7.

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