TWI750095B - Motor controller - Google Patents

Abstract

A motor controller comprises a switch circuit, a control unit, and a pulse width modulation signal, where the pulse width modulation signal has a duty cycle. The motor controller is used for driving a motor, where the motor has a coil. The switch circuit is configured to supply a coil current to the coil. The control unit is configured to generate a plurality of control signals to control the switch circuit. When the motor controller enters an early alignment state, the motor controller enables the coil current to achieve a predetermined value within one electric period. When the coil current achieves the predetermined value, the control unit records the duty cycle. The motor controller is configured to increase a success rate of starting the motor.

Description

Motor controller

The present invention relates to a motor controller, in particular to a motor controller that can increase the success rate of starting a motor.

Traditionally, the driving method of the motor can be divided into two types. One is to use the Hall sensor to switch the phase to drive the motor to run. The other is to drive the motor without a Hall sensor. Since the Hall sensor is easily affected by the external environment and the accuracy of the sensing is reduced, and the installation of the Hall sensor will increase the size and cost of the system, a driving method without a sensor has been proposed to solve the above problems. problem.

In the sensorless driving method, the designer will adjust the relevant parameters of the motor under a specific power supply voltage. When the power supply voltage changes, if the power supply voltage is too large, the coil current will be too large. If the power supply voltage is too small, it will cause the motor to fail to reach the desired speed and cause the startup to fail. Therefore, there is a need for a motor controller that can protect the motor coils under different power supply voltages and improve the success rate of starting the motor.

In view of the foregoing problems, the object of the present invention is to provide a motor controller that can increase the success rate of starting a motor.

According to the present invention, the motor controller is provided. The motor controller is used to drive the motor, and The motor can be a three-phase motor. The motor has a first coil, a second coil, and a third coil. The motor controller has a switch circuit, a control unit, and a detection unit. The switch circuit has a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a first terminal, and a second terminal Point and a third end point, wherein the switch circuit is coupled to the motor to drive the motor. The first terminal, the second terminal, and the third terminal respectively provide a first driving signal, a second driving signal, and a third driving signal to drive the motor. The first transistor is coupled to a fourth terminal and the first terminal and the second transistor is coupled to the first terminal and a fifth terminal. The third transistor is coupled to the fourth terminal and the second terminal and the fourth transistor is coupled to the second terminal and the fifth terminal. The fifth transistor is coupled to the fourth terminal and the third terminal and the sixth transistor is coupled to the third terminal and the fifth terminal. The system can provide a power voltage to the motor controller through the fourth terminal, so that the motor controller can operate normally.

One end of the first coil is coupled to the first end. One end of the second coil is coupled to the second end. One end of the third coil is coupled to the third end. The other end of the first coil is coupled to the other end of the second coil and the other end of the third coil. In other words, the first coil, the second coil, and the third coil are arranged in a Y-shaped manner. The control unit generates a first control signal, a second control signal, a third control signal, a fourth control signal, a fifth control signal, and a sixth control signal to respectively control the first transistor , The conduction status of the second transistor, the third transistor, the fourth transistor, the fifth transistor, and the sixth transistor. The detection unit is coupled to the first end, the second end, and the third end for generating a first detection signal and a second detection signal to the control unit. The detection unit can be used to detect a current of the first coil and a back electromotive force of a floating phase. The switch circuit is used for supplying the current of the first coil to the first coil. In addition, the motor controller further has a pulse width modulation signal, wherein the pulse width modulation signal has a duty cycle. The control unit receives the pulse width modulation signal to adjust a rotation speed of the motor.

First, when the motor is in a stationary state, the motor controller generates a set of fixed voltage waveforms to the first end, the second end, and the third end, so that the first drive signal, The second driving signal and the third driving signal may be a six-step square wave signal or a sine wave signal to drive the motor, respectively. At this time, the motor controller enters an initial state of positioning and causes the duty cycle of the pulse width modulation signal to change rapidly, so that the current of the first coil can quickly reach a predetermined value within an electrical cycle. When the current of the first coil reaches the predetermined value, the detection unit changes the first detection signal from a low level to a high level to notify the control unit to record the duty cycle. Then the motor controller makes the duty cycle gradually decrease at a very slow rate in order to stabilize the motor. After that, the motor controller causes the motor to accelerate. By recording the duty cycle, the motor controller can make the current of the first coil less than or equal to a magnification of the predetermined value in a startup procedure, wherein the magnification can be greater than or equal to 1. When the rotation speed of the motor reaches a predetermined rotation speed, the motor controller turns on a floating phase to detect a commutation point, wherein the floating phase is formed in the first coil. When the detection unit detects a zero-crossing point of a back electromotive force, the detection unit changes the second detection signal from the low level to the high level to notify the control unit to perform a commutation program. Therefore, the motor controller can protect the first coil under different power supply voltages and increase the success rate of starting the motor.

10: Motor controller

100: switch circuit

110: control unit

120: detection unit

101: first transistor

102: second transistor

103: Third Transistor

104: Fourth Transistor

105: Fifth Transistor

106: Sixth Transistor

W: first endpoint

U: second endpoint

V: third terminal

VCC: Fourth terminal

GND: Fifth terminal

C1: The first control signal

C2: second control signal

C3: Third control signal

C4: Fourth control signal

C5: Fifth control signal

C6: The sixth control signal

L1: first coil

L2: second coil

L3: third coil

M: Motor

ILW: Current of the first coil L1

Vp: Pulse width modulation signal

Vd1: first detection signal

Vd2: second detection signal

WO: first drive signal

UO: second drive signal

VO: third drive signal

CL: predetermined value

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

Figure 2 is a timing diagram of an embodiment of the present invention.

The following description will make the purpose, features, and advantages of the present invention more obvious. Will refer to The drawings illustrate in detail a preferred embodiment according to the present invention.

Figure 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, where the motor M can be a three-phase motor. The motor M has a first coil L1, a second coil L2, and a third coil L3. The motor controller 10 has a switch circuit 100, a control unit 110, and a detection unit 120. The switching circuit 100 has a first transistor 101, a second transistor 102, a third transistor 103, a fourth transistor 104, a fifth transistor 105, a sixth transistor 106, and a first terminal Point W, a second terminal U, and a third terminal V, where the switch circuit 100 is coupled to the motor M to drive the motor M. The first terminal W, the second terminal U, and the third terminal V provide a first driving signal WO, a second driving signal UO, and a third driving signal VO to drive the motor M, respectively. The first transistor 101 is coupled to a fourth terminal VCC and a first terminal W, and the second transistor 102 is coupled to the first terminal W and a fifth terminal GND. The third transistor 103 is coupled to the fourth terminal VCC and the second terminal U, and the fourth transistor 104 is coupled to the second terminal U and the fifth terminal GND. The fifth transistor 105 is coupled to the fourth terminal VCC and the third terminal V, and the sixth transistor 106 is coupled to the third terminal V and the fifth terminal GND. The system can provide a power voltage to the motor controller 10 via the fourth terminal VCC, so that the motor controller 10 can operate normally. The first transistor 101, the third transistor 103, and the fifth transistor 105 can each be a P-type metal oxide semi-transistor. The second transistor 102, the fourth transistor 104, and the sixth transistor 106 may each be an N-type metal oxide semi-transistor.

One end of the first coil L1 is coupled to the first end W. One end of the second coil L2 is coupled to the second end U. One end of the third coil L3 is coupled to the third end V. The other end of the first coil L1 is coupled to the other end of the second coil L2 and the other end of the third coil L3. In other words, the first coil L1, the second coil L2, and the third coil L3 are arranged in a Y-shape. The control unit 110 generates a first control signal C1, a second control signal C2, a third control signal C3, a fourth control signal C4, a fifth control signal C5, and a sixth control signal C6, respectively Control the first transistor 101, the second transistor 102, the third transistor 103, the fourth transistor 104, the fifth transistor 105, and the sixth transistor The conduction state of the crystal 106. The detection unit 120 is coupled to the first terminal W, the second terminal U, and the third terminal V to generate a first detection signal Vd1 and a second detection signal Vd2 to the control unit 110. The detecting unit 120 can be used to detect the current ILW of the first coil L1 and the back electromotive force of a floating phase. The switch circuit 100 is used to provide the current ILW of the first coil L1 to the first coil L1. In addition, the motor controller 10 further has a pulse width modulation signal Vp, wherein the pulse width modulation signal Vp has a duty cycle (Duty Cycle). The control unit 110 receives the pulse width modulation signal Vp to adjust the rotation speed of the motor M.

Figure 2 is a timing diagram of an embodiment of the present invention. First, when the motor M is in a stationary state, the motor controller 10 generates a set of fixed voltage waveforms to the first terminal W, the second terminal U, and the third terminal V, so that the first driving signals WO, The second driving signal UO and the third driving signal VO can be a six-step square wave signal or a sine wave signal to drive the motor M, respectively. At this time, the motor controller 10 enters an initial state of positioning and causes the duty cycle of the pulse width modulation signal Vp to change rapidly, so that the current ILW of the first coil L1 can quickly reach a predetermined value CL within an electrical cycle. When the current ILW of the first coil L1 reaches the predetermined value CL, the detection unit 120 changes the first detection signal Vd1 from a low level to a high level to notify the control unit 110 to record the work cycle. Then the motor controller 10 gradually reduces the duty cycle at a very slow rate, so as to stabilize the motor M. After that, the motor controller 10 causes the motor M to start to accelerate. By recording the duty cycle, the motor controller 10 can make the current ILW of the first coil L1 less than or equal to a multiple of the predetermined value CL in a startup procedure, wherein the multiple can be greater than or equal to 1. When the rotation speed of the motor M reaches a predetermined rotation speed, the motor controller 10 turns on a floating phase to detect a commutation point, where the floating phase is formed in the first coil L1. When the detection unit 120 detects a zero-crossing point of a back electromotive force, the detection unit 120 changes the second detection signal Vd2 from a low level to a high level to notify the control unit 110 to perform a commutation procedure. Therefore, the motor controller 10 can protect the first coil L1 under different power supply voltages and increase the success rate of starting the motor M. In addition, the motor controller 10 can additionally set a predetermined number of rotations to determine whether to open the floating phase to detect the commutation point. When the motor M rotates to a predetermined number of rotations, the motor controller 10 allows the floating phase to be turned on to detect the commutation point.

In order to increase the success rate of starting the motor M, the motor controller 10 is designed to successfully complete the starting procedure under different output loads. That is to say, the electrical cycle, the predetermined value CL, the predetermined rotation speed, and the predetermined number of rotations in the initial stage of positioning can all be a variable value. For example, when the motor M is in a light load state, the electrical cycle in the initial stage of positioning can be a relatively small value. When the motor M is in a heavy load state, the electrical cycle in the initial stage of positioning can be a relatively large value, so that there is enough time for the motor M to stabilize. When the motor M is in a light load state, the predetermined number of rotations can be a small value. When the motor M is in a heavy load state, the predetermined number of rotations can be a larger value.

An embodiment of the present invention utilizes a current limiting technology, so that a coil current can quickly reach a predetermined value within an electrical cycle and a work cycle is recorded at the same time. With this current limiting technology, a motor controller can protect a motor coil under different power supply voltages and increase the success rate of starting a motor. The motor controller can be applied to a single-phase motor or a multi-phase motor.

Although the present invention has been described with the preferred embodiment as an example, it should be understood that the present invention is not limited to the disclosed embodiment. On the contrary, the present invention is intended to cover various modifications and similar configurations that are obvious to those familiar with the art. Therefore, the scope of the patent application should be based on the broadest interpretation to include all such modifications and similar configurations.

The foregoing descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made in accordance with 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: detection unit

101: first transistor

102: second transistor

103: Third Transistor

104: Fourth Transistor

105: Fifth Transistor

106: Sixth Transistor

W: first endpoint

U: second endpoint

V: third terminal

VCC: Fourth terminal

GND: Fifth terminal

C1: The first control signal

C2: second control signal

C3: Third control signal

C4: Fourth control signal

C5: Fifth control signal

C6: The sixth control signal

L1: first coil

L2: second coil

L3: third coil

M: Motor

ILW: Current of the first coil L1

Vp: Pulse width modulation signal

Vd1: first detection signal

Vd2: second detection signal

Claims (18)

A motor controller, the motor controller is used to drive a motor, the motor has a coil, the motor controller includes: a switch circuit to provide a coil current to the coil; a control unit to generate a plurality of controls Signal to control the switch circuit; and a pulse width modulation signal, wherein the pulse width modulation signal has a duty cycle, and when the coil current reaches a predetermined value, the control unit records the duty cycle. In the motor controller described in item 1 of the scope of patent application, the predetermined value is a variable value. The motor controller described in item 1 of the scope of patent application, wherein the motor controller makes the coil current less than or equal to a magnification of the predetermined value in a starting procedure. The motor controller described in item 1 of the scope of patent application, wherein when a rotation speed of the motor reaches a predetermined rotation speed, the motor controller turns on a floating phase to detect a commutation point. The motor controller described in item 4 of the scope of patent application, wherein the predetermined rotation speed is a variable value. For example, in the motor controller described in item 1 of the scope of patent application, the motor controller will allow a floating phase to be turned on to detect a commutation point only after the motor has rotated to a predetermined number of rotations. The motor controller described in item 6 of the scope of patent application, wherein the predetermined number of rotations is A variable value. The motor controller described in the first item of the scope of patent application, wherein the motor controller makes an electric cycle of an initial stage of positioning a variable value. The motor controller described in claim 1, wherein the motor controller further includes a detection unit for generating a first detection signal and a second detection signal to the control unit . The motor controller described in item 1 of the scope of patent application, wherein the motor controller is applied to a single-phase motor or a multi-phase motor. A motor controller for driving a motor, the motor having a coil, the motor controller including: a switch circuit for providing a coil current to the coil; a control unit for generating a plurality of controls Signal to control the switch circuit; and a pulse width modulation signal, wherein the pulse width modulation signal has a duty cycle. When the motor controller enters an initial state of positioning, the motor controller causes the coil current to flow to an electrical A predetermined value is reached within the period. For the motor controller described in item 11 of the scope of patent application, when the coil current reaches the predetermined value, the control unit records the duty cycle. The motor controller described in item 11 of the scope of patent application, wherein the motor controller uses It is obtained that the coil current is less than or equal to a multiple of the predetermined value in a start-up procedure. For the motor controller described in item 11 of the scope of patent application, when a rotation speed of the motor reaches a predetermined rotation speed, the motor controller turns on a floating phase to detect a commutation point. For example, in the motor controller described in item 11 of the scope of patent application, when the motor rotates to a predetermined number of rotations, the motor controller allows a floating phase to be turned on to detect a commutation point. The motor controller described in item 11 of the scope of patent application, wherein the motor controller makes an electrical cycle of an initial stage of positioning a variable value. The motor controller described in claim 11, wherein the motor controller further includes a detection unit for generating a first detection signal and a second detection signal to the control unit . The motor controller described in claim 11, wherein the motor controller is applied to a single-phase motor or a multi-phase motor.

Images