TWI788911B - Motor controller - Google Patents

Abstract

A motor controller comprises a switch circuit and a control unit. The switch circuit is coupled to a motor for driving the motor. The control unit is configured to generate a control signal to control the switch circuit. The motor controller is configured to generate a current signal and a voltage signal. When a current phase of the current signal is at a predetermined crossing phase, the motor controller calculates a difference value between the current phase of the current signal and a voltage phase of the voltage signal, where the motor controller is configured to control the difference value. The motor controller may stabilize the motor and avoid noise by modulating the difference value. The motor controller may modulate the difference value, such that the difference value is equal to a predetermined phase difference.

Description

motor controller

The present invention relates to a motor controller, in particular to a motor controller applicable to a sensorless three-phase motor.

Traditionally, the driving methods of motors can be divided into two types. One is to use the Hall sensor to switch the phase and then drive the motor to run. The other is to drive the motor without Hall sensors. Since the Hall sensor is easily affected by the external environment, the sensing accuracy will decrease, and the installation of the Hall sensor will increase the size and cost of the system, so a sensorless driving method is proposed to solve the above problems. question.

In the sensorless driving method, the motor controller can detect the back electromotive force (BEMF) of the floating phase by comparing the voltage of a floating phase with a reference voltage to switch the phase. However, when the motor controller turns on the floating phase to detect the commutation point, it will cause discontinuity in the output voltage and thus generate noise.

Another prior art uses the equation: V=i×Rm+L×di/dt+BEMF to estimate the back EMF, where Rm is the motor resistance and L is the coil inductance. However, this prior art requires a complex arithmetic circuit to estimate the back EMF. Therefore, there is a need for a new technology that can use a simple arithmetic circuit to drive the motor and avoid noise.

In view of the foregoing problems, the object of the present invention is to provide a motor controller which can utilize a simple arithmetic circuit to drive a motor and avoid noise.

The motor controller is provided according to the invention. The motor controller is used to drive the motor, wherein the motor can be a three-phase motor. The motor controller has a switch circuit, a control unit, a current detection unit, a waveform processing unit, and a phase difference processing unit. The switch circuit can have a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a first terminal, a second terminal, and a third terminal, wherein the switch circuit is coupled to the motor to drive the motor. The first terminal has a current signal Iu and a voltage signal Vu to drive the motor. The first transistor, the third transistor, and the fifth transistor are respectively an upper switch. The second transistor, the fourth transistor, and the sixth transistor are respectively lower switches. The control unit generates a control signal to control the switch circuit.

The current detection unit is coupled to the switch circuit and the control unit for detecting a current phase. The current detection unit is coupled to the first terminal, the second terminal, and the third terminal. The current detection unit has a first comparator, a second comparator, a multiplexer, a first switch, a second switch, a third switch, and a resistor. The current detection unit can have three detection methods. For example, the first detection method can detect the current signal Iu to obtain the current phase. Designers can also obtain the current phase by detecting the current flowing from the second terminal to the motor or the current flowing from the third terminal to the motor. The second detection method can detect the current flowing through the resistor to obtain the current phase. The first switch is coupled to the first terminal, the first comparator, and the second comparator. The first comparator is coupled to one terminal of the first transistor and the first switch, and is used for detecting the voltage difference between the source and the drain of the first transistor to obtain the current phase. The second comparator is coupled to one terminal of the second transistor and the first switch, and is used for detecting the voltage difference between the source and the drain of the second transistor to obtain the current phase. The second switch is coupled to the second terminal, the first comparator, and the second comparator. The first comparator is coupled to one terminal of the third transistor and the second switch for detecting the third transistor The voltage difference between the source and drain of the body is used to obtain the current phase. The second comparator is coupled to one terminal of the fourth transistor and the second switch, and is used for detecting the voltage difference between the source and the drain of the fourth transistor to obtain the current phase. The third switch is coupled to the third terminal, the first comparator, and the second comparator. The first comparator is coupled to one terminal of the fifth transistor and the third switch for detecting the voltage difference between the source and the drain of the fifth transistor to obtain the current phase. The second comparator is coupled to one terminal of the sixth transistor and the third switch for detecting the voltage difference between the source and the drain of the sixth transistor to obtain the current phase. The multiplexer is coupled to an output terminal of the first comparator and an output terminal of the second comparator for generating a phase signal. The multiplexer can output the phase information of the upper switch or the phase information of the lower switch according to a selection signal, so as to realize the third detection method. In addition, the current detection unit is coupled to the switch circuit for generating the phase signal to the phase difference processing unit, wherein the phase signal represents a current phase.

The waveform processing unit can make the motor controller be in a trapezoidal wave driving mode or a sine wave driving mode. The waveform processing unit can determine whether the motor controller is in the trapezoidal wave driving mode or the sine wave driving mode according to a rotational speed information. In addition, the waveform processing unit generates a pulse width modulation signal to the control unit, wherein the pulse width modulation signal has a duty cycle. The motor controller can adjust the rotation speed of the motor according to the duty cycle.

The current signal Iu and the voltage signal Vu can be a sine wave signal respectively. When the current phase of the current signal Iu is in a predetermined crossing phase, the motor controller calculates the difference D between the current phase of the current signal Iu and the voltage phase of the voltage signal Vu, wherein the motor controller is used to control the Difference D. Specifically, the motor controller can stabilize the motor and avoid noise by adjusting the difference D. For example, when the difference D is greater than a predetermined phase difference, the motor controller gradually reduces the difference D so that the difference D is equal to the predetermined phase difference. When the difference D is smaller than the predetermined phase difference, the motor controller gradually increases the difference D so that the difference D is equal to the predetermined phase difference. When the difference D is equal to the predetermined phase difference, the motor is in a stable state. The difference D can be controlled by a phase-locked loop controller, A digital phase-locked loop controller, a proportional-integral controller, a proportional-derivative controller, or a proportional-integral-derivative controller. For example, the motor controller can utilize the current phase of the current signal Iu to modulate the voltage phase of the voltage signal Vu. The motor controller can adjust the difference D by adjusting the electrical period of the voltage signal Vu. When the difference D is greater than the predetermined phase difference, the motor controller reduces the electrical period of the voltage signal Vu. When the difference D is smaller than the predetermined phase difference, the motor controller increases the electrical period of the voltage signal Vu. Therefore, the motor controller can know when to switch phases by modulating the electrical period of the voltage signal Vu. That is to say, the motor controller can achieve a commutation function without detecting a commutation point.

According to an embodiment of the present invention, the motor controller can execute steps S41-S44 of a flow chart to make the motor run smoothly. First, the motor controller detects the current phase of the current signal Iu (step S41). Then the motor controller checks whether the current phase of the current signal Iu is in a predetermined crossover phase (step S42). The predetermined crossover phase can be 0 degrees, 60 degrees, 120 degrees, 180 degrees, 240 degrees, or 300 degrees. Designers can choose 6 predetermined crossover phases, 3 predetermined crossover phases, 2 predetermined crossover phases, or 1 predetermined crossover phase according to a required bandwidth. That is to say, the motor controller can use a plurality of predetermined crossover phases to drive the motor. For example, when the designer selects 6 predetermined crossover phases, the bandwidth is maximum and thus the motor controller can quickly stabilize the motor. When the designer selects only 1 predetermined crossover phase, the bandwidth is the smallest and thus the motor controller takes a longer time to stabilize the motor. When the current phase of the current signal Iu is at the predetermined crossing phase, the motor controller calculates the difference D between the current phase of the current signal Iu and the voltage phase of the voltage signal Vu (step S43 ). When the current phase of the current signal Iu is not in the predetermined crossover phase, the motor controller continues to detect the current phase of the current signal Iu (step S41 ). The phase difference processing unit can be used to calculate the difference D between the current phase of the current signal Iu and the voltage phase of the voltage signal Vu. Then the motor controller makes the difference D equal to a predetermined phase difference (step S44). Finally, the motor controller continues to detect the current phase of the current signal Iu (step S41). The phase difference processing unit can be used to adjust the difference D, so that the difference D equal to the predetermined phase difference. The phase difference processing unit receives the phase signal to generate a time signal to the waveform processing unit. With the information of the time signal, the waveform processing unit can adjust the electrical period of the voltage signal Vu to know when to switch the phase. Therefore, the motor controller does not need to turn on a floating phase to detect a commutation point, thereby avoiding noise. In addition, the motor controller can use a simple arithmetic circuit to drive the motor.

10: Motor controller

100: switch circuit

110: Control unit

120: Current detection unit

130: Waveform processing unit

140: Phase difference processing unit

Vc: control signal

Vpu: pulse width modulation signal

Vt: time signal

Vph: phase signal

U: first endpoint

V: second endpoint

W: the third endpoint

VCC: the fourth terminal

GND: the fifth terminal

101: The first transistor

102: second transistor

103: The third transistor

104: The fourth transistor

105: fifth transistor

106: The sixth transistor

121: The first comparator

122: Second comparator

123: multiplexer

S1: first switch

S2: second switch

S3: The third switch

R: resistance

M: motor

Vs: select signal

Iu: current signal

Vu: voltage signal

D: difference

S41, S42, S43, S44: steps

Fig. 1 is a schematic diagram of a motor controller according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a switch circuit and a current detection unit according to an embodiment of the present invention.

Fig. 3 is a timing diagram of an embodiment of the present invention.

Fig. 4 is a flowchart of an embodiment of the present invention.

The following description will make the objects, features and advantages of the present invention more apparent. Preferred embodiments according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram of a motor controller 10 according to an embodiment of the present invention. The motor controller 10 is used to drive a motor M, wherein the motor M can be a three-phase motor. The motor controller 10 has a switch circuit 100 , a control unit 110 , a current detection unit 120 , a waveform processing unit 130 , and a phase difference processing unit 140 . FIG. 2 is a schematic diagram of a switch circuit 100 and a current detection unit 120 according to an embodiment of the present invention. As shown in Figure 2, the switch circuit 100 can have a first transistor 101, a second transistor 102, a third transistor 103, a fourth transistor 104, a fifth transistor 105, a sixth transistor The transistor 106 , a first terminal U, a second terminal V, and a third terminal W, wherein the switch circuit 100 is coupled to the motor M to drive the motor M. The first terminal U has a current signal Iu and a voltage signal Vu for driving the motor M. First The transistor 101 is coupled to a fourth terminal VCC and the first terminal U and the second transistor 102 is coupled to the first terminal U and a resistor R. The third transistor 103 is coupled to the fourth terminal VCC and the second terminal V and the fourth transistor 104 is coupled to the second terminal V and the resistor R. The fifth transistor 105 is coupled to the fourth terminal VCC and the third terminal W and the sixth transistor 106 is coupled to the third terminal W and the resistor R. One terminal of the resistor R is coupled to the second transistor 102 , the fourth transistor 104 , and the sixth transistor 106 . The other terminal of the resistor R is coupled to a fifth terminal GND. The first transistor 101 , the third transistor 103 , and the fifth transistor 105 can each be a P-type metal oxide semiconductor transistor. The second transistor 102 , the fourth transistor 104 , and the sixth transistor 106 can each be an N-type metal-oxide-semiconductor transistor. In addition, the first transistor 101 , the third transistor 103 , and the fifth transistor 105 are respectively an upper switch. The second transistor 102 , the fourth transistor 104 , and the sixth transistor 106 are respectively lower switches. The control unit 110 generates a control signal Vc to control the switch circuit 100 . That is to say, the control unit 110 can be used to respectively control the conduction of the first transistor 101, the second transistor 102, the third transistor 103, the fourth transistor 104, the fifth transistor 105, and the sixth transistor 106. .

The current detection unit 120 is coupled to the switch circuit 100 and the control unit 110 for detecting a current phase. As shown in FIG. 1 or FIG. 2 , the current detection unit 120 is coupled to the first terminal U, the second terminal V, and the third terminal W. The current detection unit 120 has a first comparator 121 , a second comparator 122 , a multiplexer 123 , a first switch S1 , a second switch S2 , a third switch S3 , and a resistor R. The current detection unit 120 can have three detection methods. For example, the first detection method can detect the current signal Iu to obtain the current phase. The designer can also obtain the current phase by detecting the current flowing from the second terminal V to the motor M or the current flowing from the third terminal W to the motor M. The second detection method can detect the current flowing through the resistor R to obtain the current phase. The first switch S1 is coupled to the first terminal U, the first comparator 121 , and the second comparator 122 . The first comparator 121 is coupled to one terminal of the first transistor 101 and the first switch S1 for detecting the voltage difference between the source and drain of the first transistor 101 to obtain the current phase. The second comparator 122 is coupled to one terminal of the second transistor 102 and the first switch S1 for detecting the voltage difference between the source and the drain of the second transistor 102 to obtain the current phase. The second switch S2 is coupled to the second terminal V, the first comparator 121, and the second comparator 122 . The first comparator 121 is coupled to one terminal of the third transistor 103 and the second switch S2 for detecting the voltage difference between the source and the drain of the third transistor 103 to obtain the current phase. The second comparator 122 is coupled to one terminal of the fourth transistor 104 and the second switch S2 for detecting the voltage difference between the source and the drain of the fourth transistor 104 to obtain the current phase. The third switch S3 is coupled to the third terminal W, the first comparator 121 , and the second comparator 122 . The first comparator 121 is coupled to one terminal of the fifth transistor 105 and the third switch S3 for detecting the voltage difference between the source and the drain of the fifth transistor 105 to obtain the current phase. The second comparator 122 is coupled to one terminal of the sixth transistor 106 and the third switch S3 for detecting the voltage difference between the source and the drain of the sixth transistor 106 to obtain the current phase. The multiplexer 123 is coupled to an output terminal of the first comparator 121 and an output terminal of the second comparator 122 for generating a phase signal Vph. The multiplexer 123 can output the phase information of the upper switch or the phase information of the lower switch according to a selection signal Vs, so as to realize the third detection method. Designers can implement three detection methods, two detection methods among the three detection methods, or one detection method among the three detection methods according to actual needs. In addition, the current detection unit 120 is coupled to the switch circuit 100 for generating a phase signal Vph to the phase difference processing unit 140, wherein the phase signal Vph represents a current phase.

The waveform processing unit 130 can make the motor controller 10 in a trapezoidal wave driving mode or a sine wave driving mode. The waveform processing unit 130 can determine whether the motor controller 10 is in the trapezoidal wave driving mode or the sine wave driving mode according to a rotational speed information. In addition, the waveform processing unit 130 generates a pulse width modulation signal Vpu to the control unit 110, wherein the pulse width modulation signal Vpu has a duty cycle (Duty Cycle). The motor controller 10 can adjust the rotation speed of the motor M according to the duty cycle.

FIG. 3 is a timing diagram of an embodiment of the present invention, wherein the current signal Iu and the voltage signal Vu are respectively a sine wave signal. When the current phase of the current signal Iu is in a predetermined crossing phase, the motor controller 10 calculates the difference D between the current phase of the current signal Iu and the voltage phase of the voltage signal Vu, wherein the motor controller 10 controls the difference D. Specifically, the motor controller 10 can stabilize the motor M and avoid noise by modulating the difference D. For example, when the difference D is greater than a predetermined phase difference, the motor controller 10 gradually The difference D is reduced so that the difference D is equal to the predetermined phase difference. When the difference D is smaller than the predetermined phase difference, the motor controller 10 gradually increases the difference D so that the difference D is equal to the predetermined phase difference. When the difference D is equal to the predetermined phase difference, the motor M is in a stable state. The difference D can be controlled by a phase lock loop (Phase Lock Loop) controller, a digital phase lock loop (Digital Phase Lock Loop) controller, a proportional-integral (Proportional-Integral) controller, a proportional-derivative (Proportional- Derivative) controller, or a proportional-integral-derivative (Proportional-Integral-Derivative) controller. Designers can use one of the above-mentioned controllers to adjust the difference D. For example, the motor controller 10 can use the current phase of the current signal Iu to modulate the voltage phase of the voltage signal Vu. The motor controller 10 can adjust the difference D by adjusting the electrical period of the voltage signal Vu. Designers can also adjust the difference D by adjusting other parameters. When the difference D is greater than the predetermined phase difference, the motor controller 10 reduces the electrical period of the voltage signal Vu. When the difference D is smaller than the predetermined phase difference, the motor controller 10 increases the electrical period of the voltage signal Vu. Therefore, the motor controller 10 can know when to switch the phase by modulating the electrical period of the voltage signal Vu. That is to say, the motor controller 10 can achieve a commutation function without detecting the commutation point. In addition, the predetermined phase difference is related to the rotational speed of the motor. Generally speaking, when the rotation speed of the motor is higher, the predetermined phase difference is smaller. The motor controller 10 can use a look-up table method (Look-Up Table) to store the relationship between the predetermined phase difference and the rotational speed of the motor. To sum up, the motor controller 10 does not need to turn on the floating phase, thus avoiding noise. That is to say, the motor controller 10 does not need to detect a back EMF and the voltage signal Vu is independent of the back EMF, so the technique of the present invention is independent of the back EMF. The motor controller 10 can use a simple arithmetic circuit to drive the motor M.

Fig. 4 is a flowchart of an embodiment of the present invention. First, the motor controller 10 detects the current phase of the current signal Iu (step S41). Then the motor controller 10 checks whether the current phase of the current signal Iu is in a predetermined crossover phase (step S42). The predetermined crossover phase may be 0 degrees, 60 degrees, 120 degrees, 180 degrees, 240 degrees, or 300 degrees. Designers can choose 6 predetermined crossover phases, 3 predetermined crossover phases, 2 predetermined crossover phases, or 1 predetermined crossover phase according to the required bandwidth. That is to say, the motor controller 10 can drive the motor M with a plurality of predetermined crossover phases. For example, when the designer selects 6 predetermined When the phases are crossed, the bandwidth is at a maximum and thus the motor controller 10 can stabilize the motor M quickly. When the designer only selects 1 predetermined crossover phase, the bandwidth is the smallest and thus the motor controller 10 needs a longer time to stabilize the motor M. When the current phase of the current signal Iu is at the predetermined crossing phase, the motor controller 10 calculates the difference D between the current phase of the current signal Iu and the voltage phase of the voltage signal Vu (step S43 ). When the current phase of the current signal Iu is not in the predetermined crossing phase, the motor controller 10 continues to detect the current phase of the current signal Iu (step S41 ). The phase difference processing unit 140 can be used to calculate the difference D between the current phase of the current signal Iu and the voltage phase of the voltage signal Vu. Then the motor controller 10 makes the difference D equal to a predetermined phase difference (step S44). Finally, the motor controller 10 continues to detect the current phase of the current signal Iu (step S41). The phase difference processing unit 140 is configured to modulate the difference D so that the difference D is equal to a predetermined phase difference. That is, the phase difference processing unit 140 may have a PLL controller, a digital PLL controller, a proportional-integral controller, a proportional-derivative controller, or a proportional-integral-derivative controller to control the difference D. In addition, the phase difference processing unit 140 may also have a look-up table method to store the relationship between the predetermined phase difference and the rotational speed of the motor. The phase difference processing unit 140 receives the phase signal Vph to generate a time signal Vt to the waveform processing unit 130 . With the information of the time signal Vt, the waveform processing unit 130 can adjust the electrical period of the voltage signal Vu to know when to switch the phase. Specifically, when the rotation speed of the motor M changes, the motor controller 10 will execute the steps S41-S44 of the flow chart again to make the motor M run smoothly.

According to an embodiment of the present invention, the motor controller 10 can be applied to a sensorless motor. In addition, the motor controller 10 can also be applied to a single-phase motor, a multi-phase motor, a brushless motor, or a DC motor. In summary, when the current phase of the current signal Iu is in a predetermined crossover phase, the motor controller 10 calculates the difference D between the current phase of the current signal Iu and the voltage phase of the voltage signal Vu. The motor controller 10 modulates the difference D such that the difference D is equal to a predetermined phase difference. The motor controller 10 can achieve a phase commutation function without turning on a floating phase. The motor controller 10 can achieve a commutation function without detecting a back electromotive force. Therefore, the motor controller 10 can use a simple arithmetic circuit to drive the motor M without noise.

While the invention has been described by way of illustration of preferred embodiments, it should be understood that: The invention is not limited to the disclosed embodiments. On the contrary, the invention is intended to cover various modifications and similar arrangements apparent to those skilled in the art. Accordingly, the scope of claims should be construed in the broadest way to encompass all such modifications and similar arrangements.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

10: Motor controller

100: switch circuit

110: Control unit

120: Current detection unit

130: Waveform processing unit

140: Phase difference processing unit

Vc: control signal

Vpu: pulse width modulation signal

Vt: time signal

Vph: phase signal

U: first endpoint

V: second endpoint

W: the third endpoint

M: motor

Claims (27)

A motor controller, comprising: a switch circuit coupled to a motor for driving the motor; and a control unit for generating a control signal to control the switch circuit, wherein the motor controller is used for generating a current signal and a voltage signal, when a current phase of the current signal is in a predetermined crossover phase, the motor controller calculates a difference between the current phase of the current signal and a voltage phase of the voltage signal, the motor controller is used to Control this difference. The motor controller as described in item 1 of the scope of the patent application, wherein the motor controller does not need to open a floating phase to achieve a phase commutation function. The motor controller described in item 1 of the scope of the patent application, wherein the motor controller does not need to detect a counter electromotive force to achieve a commutation function. The motor controller as described in item 1 of the scope of the patent application, wherein the difference is controlled by a phase-locked loop controller. The motor controller as described in item 1 of the scope of the patent application, wherein the motor controller modulates the difference by adjusting an electrical period of the voltage signal. The motor controller as described in claim 5, wherein when the difference is greater than a predetermined phase difference, the motor controller reduces the electrical period of the voltage signal. The motor controller as described in item 5 of the scope of the patent application, wherein when the difference is less than a preset To determine the phase difference, the motor controller increases the electrical period of the voltage signal. The motor controller as described in claim 1, wherein the motor controller modulates the difference so that the difference is equal to a predetermined phase difference. The motor controller as described in claim 8, wherein the predetermined phase difference is related to the rotational speed of the motor. The motor controller as described in claim 9 of the patent application, wherein the predetermined phase difference becomes smaller when the rotational speed of the motor is higher. The motor controller as described in item 1 of the patent claims, wherein the predetermined crossover phase is 0 degree, 60 degree, 120 degree, 180 degree, 240 degree, or 300 degree. The motor controller as described in item 1 of the scope of the patent application, wherein the motor controller stabilizes the motor by adjusting the difference. The motor controller as described in item 1 of the scope of the patent application, wherein the motor controller avoids noise by modulating the difference. The motor controller as described in item 1 of the scope of the patent application, wherein the motor controller further includes a current detection unit, the current detection unit includes a resistor, and the resistor is coupled to the switch circuit. The motor controller described in item 1 of the scope of the patent application, wherein the motor controller is more A current detection unit is included, the current detection unit includes a first switch, and the first switch is coupled to the switch circuit. The motor controller as described in claim 15, wherein the current detection unit further includes a first comparator, and the first comparator is coupled to the first switch. The motor controller as described in claim 15, wherein the current detection unit further includes a second switch, and the second switch is coupled to the switch circuit. The motor controller as described in item 1 of the scope of the patent application, wherein the motor controller further includes: a phase difference processing unit; and a current detection unit coupled to the switching circuit for generating a phase signal to the phase Poor processing unit. The motor controller as described in claim 18, wherein the phase difference processing unit includes a phase-locked loop controller to control the difference. The motor controller described in claim 18 of the patent application, wherein the motor controller further includes a waveform processing unit, and the phase difference processing unit receives the phase signal to generate a time signal to the waveform processing unit. The motor controller as described in claim 20, wherein the waveform processing unit enables the motor controller to be in a trapezoidal wave driving mode or a sine wave driving mode. The motor controller as described in claim 21 of the patent application, wherein the waveform processing unit determines whether the motor controller is in the trapezoidal wave driving mode or the sine wave driving mode according to a rotational speed information. The motor controller as described in claim 20 of the patent application, wherein the waveform processing unit generates a pulse width modulation signal to the control unit, the pulse width modulation signal has a duty cycle, and the motor controller is based on the duty cycle to adjust the speed of one of the motors. The motor controller as described in claim 1, wherein the voltage signal has nothing to do with a counter electromotive force. The motor controller as described in Claim 1 of the present invention, wherein the motor controller utilizes a plurality of the predetermined crossover phases to drive the motor. The motor controller as described in claim 1 of the patent application, wherein the motor controller is applied to a sensorless motor. The motor controller described in claim 1 of the patent application, wherein the motor controller is applied to a single-phase motor, a multi-phase motor, a brushless motor, or a DC motor.

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