TW202304124A - 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 generates a control signal to control the switch circuit. The motor controller determines a non-excitation time. When the motor is in a locked state, the motor controller enables the non-excitation time to be a variable value. The motor controller utilizes the non-excitation time to achieve a lock protection function. The motor controller determines whether the motor is in the locked state by detecting a rotor speed or a rotor temperature. Moreover, the motor controller further comprises a driving signal, where the driving signal has the non-excitation time.

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 will switch the phase by detecting the counter electromotive force of the floating phase, and then drive the motor.

FIG. 1 is a timing diagram of a conventional driving signal Vd, wherein the driving signal Vd has an excitation time and a non-excitation time. When the motor is affected by an external force and the rotor of the motor is blocked at a certain position, the coil of the motor will continue to exert force and the temperature will be too high. At this time, the conventional technology adopts a fixed excitation time and a fixed non-excitation time to achieve a stall protection function. When the motor is operated during the excitation time, it will cause the temperature to rise. On the contrary, when the motor is operated in the non-excitation time, the temperature will drop. Therefore, the motor controller will make the non-excitation time longer than the excitation time to achieve the purpose of reducing the temperature. However, when the motor controller fails to start the motor successfully for the first time, the motor controller needs to wait for a non-excitation time before starting again, thus causing the starting time to be too long. Therefore, when the motor is in a locked-rotor state, a new technology is required to increase the number of restarts within a limited time and improve the success rate of a start.

In view of the foregoing problems, the purpose of the present invention is to provide a motor controller that can increase the number of restarts within a limited time and improve the success rate of a start.

The motor controller is provided according to the invention. The motor controller is used to drive a motor. The motor controller has a switch circuit, a control circuit, a locked-rotor protection unit, a rotor detection unit, a non-excitation time modulation unit, a counting unit, an input voltage detection unit, and a temperature detection unit. The switch circuit is coupled to the motor for driving the motor. The control unit generates a control signal to the switch circuit for controlling the switch circuit. The rotor detecting unit generates a first detection signal to the locked-rotor protection unit to inform the locked-rotor protection unit whether the motor is in a locked-rotor state. For example, the rotor detection unit can determine whether the motor is in the locked-rotor state by detecting a rotor speed or a rotor temperature. The locked-rotor protection unit is coupled to the control unit for generating a driving signal to the control unit, wherein the driving signal has an excitation time and a non-excitation time. When the motor is in the stalled state, the motor controller can make the excitation time a fixed value and the non-excitation time a variable value to achieve a stall protection function. The non-excitation time modulation unit generates a timing signal to the stall protection unit to indicate the non-excitation time. For example, the driving signal may have a first excitation time, a first de-excitation time, a second excitation time, a second non-excitation time, a third excitation time, and a third non-excitation time. The motor controller can make the first energization time equal to the second energization time and the second energization time equal to the third energization time. The motor controller can make the second de-energization time longer than the first de-energization time and the third de-energization time longer than the second de-energization time. With this control mechanism, the motor controller can increase the number of restarts within the limited time and improve the success rate of starting. That is, the motor controller can solve a delayed start problem and improve the efficiency of a system. In addition, the motor controller can make the second non-excitation time longer than the second excitation time and the third non-excitation time longer than the third excitation time, so as to reduce the temperature and achieve the stall protection function. The present invention can have at least three or more embodiments as follows:

1. The motor controller makes the non-excitation time vary with the number of times. When the motor is in the locked-rotor state, the motor controller can make the first non-excitation time a smaller value and the second non-excitation time a larger value. That is to say, when the number of times is larger, the non-excitation time is longer. The counting unit can generate a counting signal to the non-excitation time modulation unit to represent the number of times. The non-excitation time modulation unit can adjust the non-excitation time according to the count signal. After the motor controller starts the motor successfully, the counting unit can be reset to recount the number of times. For example, the first non-excitation time may be 5 seconds and the N-th non-excitation time may be 10 seconds, wherein N is a positive integer greater than 1.

2. The motor controller makes the non-excitation time vary with an input voltage, wherein the input voltage can be a power supply voltage. The input voltage detection unit can generate a second detection signal to the non-excitation time modulation unit to represent the input voltage. The non-excitation time modulation unit can modulate the non-excitation time according to the second detection signal. When the input voltage is larger, the non-excitation time is longer. For example, when the input voltage is a first voltage, the non-excitation time may be 5 seconds. When the input voltage is a second voltage, the non-excitation time may be 10 seconds, wherein the second voltage is greater than the first voltage.

3. The motor controller makes the non-excitation time vary with a temperature. The temperature detection unit can generate a third detection signal to the non-excitation time modulation unit to indicate the temperature. The non-excitation time modulation unit can modulate the non-excitation time according to the third detection signal. When the temperature is higher, the non-excitation time is longer. For example, when the temperature is 25° C., the non-excitation time may be 5 seconds. When the temperature is 80°C, the non-excitation time may be 10 seconds.

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. 2 is a schematic diagram of a motor controller 10 according to an embodiment of the present invention, wherein the motor controller 10 is used to drive a motor M. The motor controller 10 has a switch circuit 100, a control circuit 110, a locked-rotor protection unit 120, a rotor detection unit 130, a non-excitation time modulation unit 140, a counting unit 150, and an input voltage detection unit 160 , and a temperature detection unit 170 . The switch circuit 100 is coupled to the motor M for driving the motor M. As shown in FIG. The motor M has a rotor and the motor M can be a three-phase motor. When the motor M is a three-phase motor, the switch circuit 100 may have three half bridge (Half Bridge) circuits to drive the motor M. The control unit 110 generates a control signal Vc to the switch circuit 100 for controlling the switch circuit 100 . The rotor detection unit 130 generates a first detection signal Vde1 to the stall protection unit 120 to inform the stall protection unit 120 whether the motor M is in a stall state. For example, the rotor detection unit 130 can determine whether the motor M is in a locked-rotor state by detecting the rotational speed or the temperature of the rotor. The locked-rotor protection unit 120 is coupled to the control unit 110 for generating a driving signal Vd to the control unit 110 , wherein the driving signal Vd has an excitation time and a non-excitation time. When the motor M is in a stalled state, the motor controller 10 can make the excitation time a fixed value and the non-excitation time a variable value to achieve a stall protection function. The non-excitation time modulation unit 140 generates a timing signal Vt to the stall protection unit 120 to indicate the non-excitation time. FIG. 3 is a timing diagram of the driving signal Vd according to an embodiment of the present invention. For example, the driving signal Vd may have a first excitation time, a first non-excitation time, a second excitation time, a second non-excitation time, a third excitation time, and a third non-excitation time. The motor controller 10 may make the first energization time equal to the second energization time and the second energization time equal to the third energization time. The motor controller 10 can make the second non-excitation time longer than the first non-excitation time and the third non-excitation time longer than the second non-excitation time. With this control mechanism, the motor controller 10 can increase the number of restarts within a limited time and improve the success rate of a start. That is, the motor controller 10 can solve a delayed start problem and improve the efficiency of the system. In addition, the motor controller 10 can make the second non-excitation time longer than the second excitation time and the third non-excitation time longer than the third excitation time, so as to reduce the temperature and achieve the stall protection function. The present invention can have at least three or more embodiments as follows:

1. The motor controller 10 makes the non-excitation time vary with the number of times. When the motor M is in a locked-rotor state, the motor controller 10 can make the first non-excitation time a smaller value and the second non-excitation time a larger value. That is to say, when the number of times is larger, the non-excitation time is longer. The counting unit 150 can generate a counting signal Vco to the de-energized time modulation unit 140 to indicate the number of times. The non-excitation time modulation unit 140 can modulate the non-excitation time according to the count signal Vco. After the motor controller 10 starts the motor M successfully, the counting unit 150 can be reset to recount the number of times. Fig. 4 is a relational diagram of non-excitation time and times in the first embodiment of the present invention. For example, the first non-excitation time may be 5 seconds and the N-th non-excitation time may be 10 seconds, wherein N is a positive integer greater than 1. As shown in Figure 4, the non-excitation time can be proportional to the number of times. By gradually increasing the non-excitation time, the motor controller 10 can increase the number of restarts within a limited time and achieve a stall protection function.

2. The motor controller 10 makes the non-excitation time vary with an input voltage, wherein the input voltage can be a power supply voltage. The input voltage detection unit 160 can generate a second detection signal Vde2 to the deactivation time modulation unit 140 to represent the input voltage. The non-excitation time modulation unit 140 can modulate the non-excitation time according to the second detection signal Vde2. When the input voltage is larger, the non-excitation time is longer. Fig. 5 is a relation diagram of non-excitation time and input voltage in the second embodiment of the present invention. For example, when the input voltage is a first voltage V1, the non-excitation time may be 5 seconds. When the input voltage is a second voltage V2, the non-excitation time may be 10 seconds, wherein the second voltage V2 is greater than the first voltage V1. As shown in Figure 5, the non-excitation time can be proportional to the input voltage. Therefore, when the input voltage is a low voltage, the motor controller 10 can increase the number of restarts within a limited time and achieve a locked-rotor protection function.

3. The motor controller 10 makes the non-excitation time vary with a temperature. The temperature detection unit 170 can generate a third detection signal Vde3 to the de-excitation time modulation unit 140 to indicate the temperature. The non-excitation time modulation unit 140 can modulate the non-excitation time according to the third detection signal Vde3. When the temperature is higher, the non-excitation time is longer. Fig. 6 is a relation diagram of non-excitation time and temperature in the third embodiment of the present invention. For example, when the temperature is 25°C, the non-excitation time may be 5 seconds. When the temperature is 80°C, the non-excitation time can be 10 seconds. As shown in Figure 6, the non-excitation time can be proportional to the temperature. Therefore, when the temperature is very low, the motor controller 10 can increase the number of restarts within a limited time and achieve a locked-rotor protection function.

Specifically, the designer can implement the three embodiments, two of the three embodiments, or one of the three embodiments according to actual needs. According to an embodiment of the present invention, the motor controller 10 can be applied to a sensorless motor. The motor controller 10 is used to determine an excitation time and a non-excitation time. When the motor M is in a locked-rotor state, the motor controller 10 can make the non-excitation time a variable value. The motor controller 10 utilizes the non-excitation time to achieve a locked-rotor protection function.

Although the present invention has been described by way of examples of preferred embodiments, it should be understood that the present 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 M: motor 100: switch circuit 110: Control unit 120: Stall protection unit 130: Rotor detection unit 140: Non-excitation time modulation unit 150: counting unit 160: Input voltage detection unit 170: Temperature detection unit Vc: control signal Vd: drive signal Vt: timing signal Vde1: the first detection signal Vde2: the second detection signal Vde3: the third detection signal Vco: counting signal N: times V1: first voltage V2: second voltage

Figure 1 is a timing diagram of a conventional drive signal. Fig. 2 is a schematic diagram of a motor controller according to an embodiment of the present invention. Fig. 3 is a timing diagram of driving signals according to an embodiment of the present invention. Fig. 4 is a relational diagram of non-excitation time and times in the first embodiment of the present invention. Fig. 5 is a relation diagram of non-excitation time and input voltage in the second embodiment of the present invention. Fig. 6 is a relation diagram of non-excitation time and temperature in the third embodiment of the present invention.

10: Motor controller

M: motor

100: switch circuit

110: Control unit

120: Stall protection unit

130: Rotor detection unit

140: Non-excitation time modulation unit

150: counting unit

160: Input voltage detection unit

170: Temperature detection unit

Vc: control signal

Vd: drive signal

Vt: timing signal

Vde1: the first detection signal

Vde2: the second detection signal

Vde3: the third detection signal

Vco: counting signal

Claims (24)

A motor controller comprising: a switching circuit coupled to a motor for driving the motor; and A control unit is used to generate a control signal to control the switch circuit, wherein the motor controller determines a non-excitation time, and when the motor is in a locked-rotor state, the motor controller makes the non-excitation time a variable value. The motor controller described in claim 1 of the patent application, wherein the motor controller utilizes the non-excitation time to achieve a locked-rotor protection function. The motor controller as described in item 1 of the scope of the patent application, wherein the motor controller determines whether the motor is in the locked-rotor state by detecting a rotor speed. The motor controller as described in claim 1 of the patent application, wherein the motor controller determines whether the motor is in the locked-rotor state by detecting a rotor temperature. The motor controller as described in item 1 of the scope of the patent application, wherein the motor controller further has a driving signal, and the driving signal has the non-excitation time. The motor controller as described in item 5 of the scope of the patent application, wherein the motor controller further has a locked-rotor protection unit, and the locked-rotor protection unit is coupled to the control unit for generating the driving signal to the control unit. The motor controller as described in item 6 of the scope of the patent application, wherein the motor controller further has a rotor detection unit, and the rotor detection unit generates a first detection signal to the stall protection unit. The motor controller as described in item 6 of the scope of the patent application, wherein the motor controller further has a non-excitation time modulation unit, and the non-excitation time modulation unit generates a timing signal to the stall protection unit. The motor controller as described in claim 8 of the patent application, wherein the motor controller further has a counting unit, and the counting unit generates a counting signal to the non-excitation time modulation unit. The motor controller as described in claim 9, wherein the counting unit is reset after the motor controller successfully starts the motor. The motor controller as described in claim 8 of the patent application, wherein the motor controller further has an input voltage detection unit, and the input voltage detection unit generates a second detection signal to the non-excitation time modulation unit. The motor controller as described in claim 8 of the patent application, wherein the motor controller further has a temperature detection unit, and the temperature detection unit generates a third detection signal to the non-excitation time modulation unit. The motor controller as described in item 1 of the scope of the patent application, wherein the motor controller further has an excitation time, and when the motor is in the locked-rotor state, the motor controller makes the excitation time a fixed value. The motor controller as described in item 1 of the scope of the patent application, wherein the motor controller makes the non-excitation time change with a count. As for the motor controller described in item 14 of the scope of the patent application, the non-excitation time is longer when the number of times is larger. The motor controller as described in claim 1 of the patent application, wherein the motor controller makes the non-excitation time vary with an input voltage. The motor controller as described in claim 16, wherein the input voltage is a power supply voltage. The motor controller as described in item 16 of the scope of the patent application, wherein the non-excitation time is longer when the input voltage is larger. The motor controller as described in item 1 of the patent claims, wherein the motor controller makes the non-excitation time vary with a temperature. As for the motor controller described in claim 19 of the patent application, the non-excitation time is longer when the temperature is higher. The motor controller as described in claim 1 of the patent application, wherein the motor is a three-phase 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 as described in item 1 of the scope of the patent application, wherein the motor controller increases a number of restarts within a limited time. The motor controller described in item 1 of the scope of the patent application, wherein the motor controller is used to improve a startup success rate.

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