TW202213914A - Motor system - Google Patents

Abstract

The present invention discloses a motor system without a hall sensing element. The motor system comprises a first output pin, a second output pin, an auxiliary pin, a stator, a rotor, a primary coil, and an auxiliary coil. Both the primary coil and the auxiliary coil surround the stator. The primary coil is coupled to the first output pin and the second output pin. The auxiliary coil is coupled to the auxiliary pin. The auxiliary coil is configured to determine a phase switching time point. The motor system detects the zero point of the voltage of the auxiliary pin, so as to detect the position of the rotor and determine the phase switching time point.

Description

motor system

The present invention relates to a motor system, and more particularly, to a motor system that does not require Hall sensing elements.

FIG. 1 is a schematic diagram of a conventional motor module 10 . The motor module 10 has a rotor 100 , a stator 110 , and a winding 120 . The rotor 100 may be divided into 4 magnetic poles to switch phases, wherein each of the magnetic poles N and the magnetic poles S are two. The winding 120 can be wound on the stator 110 to change the magnetic field by electromagnetic induction to drive the rotor 100 . FIG. 2 is a schematic diagram of a conventional motor system 1 . Please refer to Figure 1 and Figure 2 at the same time. The motor system 1 has a motor controller 20 and a Hall sensing element 200 . The motor controller 20 provides a fixed voltage to the Hall sensing element 200 via the terminal HB. The Hall sensing element 200 can be disposed near the winding 120 to sense the change of the magnetic field generated by the rotation of the rotor 100, thereby detecting the position of the rotor 100 and respectively generating a first sensing signal and a second sensing signal to the position of the rotor 100. The terminal HALL1 and the terminal HALL2 are used for the motor controller 20 to switch phases. FIG. 3 is a timing diagram corresponding to the correlation signal of FIG. 2 . The motor controller 20 commutates the first terminal O1 and the second terminal O2 according to the first sensing signal and the second sensing signal to generate an AC signal to drive the motor module 10 . However, the sensing error of the Hall sensing element 200 may degrade the performance of the motor module 10 . In addition, the disposition of the Hall sensing element 200 increases the volume and cost of the motor system 1 at the same time, which is not conducive to integrating the motor system 1 into an electronic device.

Therefore, how to replace the Hall sensing element to reduce the volume and cost of the motor system is an important issue to be solved at present.

In view of the aforementioned problems, an object of the present invention is to provide a motor system without Hall sensing elements.

The motor system is provided in accordance with the present invention. The motor system has a motor module and a motor controller. The motor module has a rotor, a stator, and a winding. The rotor can be divided into 4 poles to switch the phase, with two poles N and two poles S each. The winding can be wound on the stator, and the surrounding magnetic field is changed by electromagnetic induction to drive the rotor. The winding has a main coil and an auxiliary coil, wherein the auxiliary coil is used to determine a commutation time point, thereby replacing the Hall sensing element. The motor controller has a first terminal, a second terminal, a first auxiliary terminal, a second auxiliary terminal, a terminal VCC, and a terminal GND. The main coil is coupled to the first terminal and the second terminal and the auxiliary coil is coupled to the first auxiliary terminal and the second auxiliary terminal. The motor system can determine the commutation time point according to the voltage of the first auxiliary terminal.

The motor controller further has a switch circuit, a control unit, a current detection unit, and a voltage detection unit. The switch circuit has a first transistor, a second transistor, a third transistor, and a fourth transistor. The switch circuit is used for providing a driving current to the main coil. The first transistor is coupled to the terminal VCC and the first terminal and the second transistor is coupled to the first terminal and the terminal GND. The third transistor is coupled to the terminal VCC and the second terminal and the fourth transistor is coupled to the second terminal and the terminal GND. The first transistor, the second transistor, the third transistor, and the fourth transistor can be a P-type MOSFET or an N-type MOSFET. The current detection unit is coupled to the first terminal and the second terminal for generating a first detection signal to the control unit to detect the zero point of the driving current. The voltage detection unit is coupled to the first auxiliary terminal for generating a second detection signal to the control unit to detect the voltage zero of the first auxiliary terminal. The control unit generates a plurality of control signals to control the switch circuit.

When the voltage of the first terminal changes from a high level to a low level, the driving current starts to decrease gradually. When the driving current drops to 0, the voltage of the first auxiliary terminal rises from 0 to an intermediate value and then drops back to 0. At this time, the last voltage zero point of the first auxiliary terminal can be regarded as a commutation time point. Therefore, when the current detection unit detects the zero point of the driving current, the first detection signal will change from the low level to the high level to notify the control unit to start detecting the voltage of the first auxiliary terminal zero. When the voltage detection unit detects the voltage zero of the first auxiliary terminal, the second detection signal will change from the low level to the high level to inform the control unit that the current time point is the commutation point in time. Whether the motor module is in a startup mode or a normal operation mode, the auxiliary coil can be used to determine the commutation time point.

The objects, features, and advantages of the present invention will become more apparent from the following description. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 4 is a schematic diagram of a motor module 30 according to an embodiment of the present invention. The motor module 30 has a rotor 300 , a stator 310 , and a winding 320 . The rotor 300 may be divided into 4 magnetic poles to switch phases, wherein each of the magnetic poles N and the magnetic poles S are two. The winding 320 can be wound on the stator 310 to change the magnetic field by electromagnetic induction to drive the rotor 300 . The winding 320 has a main coil 321 and an auxiliary coil 322, wherein the auxiliary coil 322 is used to determine a commutation time point, thereby replacing a Hall sensing element. The main coil 321 has a first number of turns N1 and the auxiliary coil 322 has a second number of turns N2, wherein N1/N2≥1. FIG. 5 is a schematic diagram of the motor controller 40 and the windings 320 according to an embodiment of the present invention. The motor controller 40 has a first terminal O1, a second terminal O2, a first auxiliary terminal AUX1, a second auxiliary terminal AUX2, a terminal VCC, and a terminal GND. The terminal VCC and the terminal GND are coupled to a voltage source. The main coil 321 is coupled to the first terminal O1 and the second terminal O2 and the auxiliary coil 322 is coupled to the first auxiliary terminal AUX1 and the second auxiliary terminal AUX2. The second auxiliary terminal AUX2 can be coupled to the first terminal O1, the second terminal O2, or a reference voltage. Therefore, the auxiliary coil 322 may be coupled to the first terminal O1, the second terminal O2, or the reference voltage. In addition, the motor controller 40 of an embodiment of the present invention can be packaged as a motor driver IC (Integrated Circuit), wherein the motor driver IC can have a first output pin, a second output pin, an auxiliary pin, a a first voltage pin, and a second voltage pin. The first output pin is coupled to the first terminal O1. The second output pin is coupled to the second terminal O2. The auxiliary pin is coupled to the first auxiliary terminal AUX1. The first voltage pin is coupled to the terminal VCC. The second voltage pin is coupled to the terminal GND. One end of the auxiliary coil 322 can be coupled to the first output pin, the second output pin, or the reference voltage.

FIG. 6 is a schematic diagram of a motor system 3 according to an embodiment of the present invention. The motor system 3 includes a motor module 30 and a motor controller 40 . The motor controller 40 further has a switch circuit 400 , a control unit 410 , a current detection unit 420 , and a voltage detection unit 430 . The switch circuit 400 is coupled to the terminal VCC and the terminal VCC generates a supply current IVCC to the switch circuit 400 . The switch circuit 400 is used to provide a driving current to the main coil 321, wherein the driving current can be analogous to the supply current IVCC. The switch circuit 400 has a first transistor 401 , a second transistor 402 , a third transistor 403 , and a fourth transistor 404 . The first transistor 401 is coupled to the terminal VCC and the first terminal O1 and the second transistor 402 is coupled to the first terminal O1 and the terminal GND. The third transistor 403 is coupled to the terminal VCC and the second terminal O2 and the fourth transistor 404 is coupled to the second terminal O2 and the terminal GND. The first transistor 401, the second transistor 402, the third transistor 403, and the fourth transistor 404 can be a P-type MOSFET or an N-type MOSFET. In FIG. 6 , the first transistor 401 and the third transistor 403 are two P-type MOSFETs as an example. The second transistor 402 and the fourth transistor 404 are two N-type MOS transistors as an example. The current detection unit 420 is coupled to the first terminal O1 and the second terminal O2 for generating a first detection signal Vd1 to the control unit 410 to detect the zero point of the driving current. The voltage detection unit 430 is coupled to the first auxiliary terminal AUX1 for generating a second detection signal Vd2 to the control unit 410 to detect the voltage zero of the first auxiliary terminal AUX1. The motor system 3 can determine the commutation time point according to the voltage of the first auxiliary terminal AUX1.

The control unit 410 generates a first control signal C1, a second control signal C2, a third control signal C3, and a fourth control signal C4 for controlling the first transistor 401, the second transistor 402, the third The switching situation of the three transistors 403 and the fourth transistor 404 . The control unit 410 alternates between a first driving mode and a second driving mode to provide power to the motor module 30 . In the first driving mode, the control unit 410 turns on the first transistor 401 and the fourth transistor 404 by controlling the first control signal C1 and the fourth control signal C4. At this time, the current flows from the terminal VCC through the first transistor 401 , the main coil 321 , the fourth transistor 404 , and the terminal GND in sequence, so as to transmit power to the motor module 30 in this mode. In the second driving mode, the control unit 410 turns on the second transistor 402 and the third transistor 403 by controlling the second control signal C2 and the third control signal C3. At this time, the current flows from the terminal VCC through the third transistor 403 , the main coil 321 , the second transistor 402 , and the terminal GND in sequence, so as to transmit power to the motor module 30 in this mode. By repeatedly switching between the first driving mode and the second driving mode, the motor module 30 can operate normally.

FIG. 7 is a timing diagram of an embodiment of the present invention. Please refer to Figure 6 and Figure 7 at the same time. Specifically, the motor system 3 according to an embodiment of the present invention detects the position of the rotor 300 and determines the commutation time point by detecting the voltage zero point of the first auxiliary terminal AUX1. When the voltage of the first terminal O1 changes from a high level H to a low level L, the driving current starts to decrease gradually. When the driving current drops to 0, the voltage of the first auxiliary terminal AUX1 will rise from 0 to an intermediate value and then drop to 0 again. At this time, the voltage zero point of the last first auxiliary terminal AUX1 can be regarded as a commutation time point T1. Similarly, by the same method, the subsequent commutation time points T2-T4 can also be obtained. Therefore, when the current detection unit 420 detects the zero point of the driving current, the first detection signal Vd1 will change from the low level L to the high level H to notify the control unit 410 to start detecting the voltage zero point of the first auxiliary terminal AUX1 . When the voltage detection unit 430 detects the voltage zero of the first auxiliary terminal AUX1, the second detection signal Vd2 changes from the low level L to the high level H to inform the control unit 410 that the current time point is the commutation time point. Whether the motor module 30 is in a startup state or a normal operation state, the voltage of the auxiliary coil 322 and the first auxiliary terminal AUX1 can be used to determine the commutation time point.

The motor system 3 of an embodiment of the present invention can be applied to a single-phase brushless DC motor. The motor system 3 may have a first output pin, a second output pin, an auxiliary pin, a stator 310 , a rotor 300 , a main coil 321 , and an auxiliary coil 322 . Both the main coil 321 and the auxiliary coil 322 are wound on the stator 310 . The main coil 321 is coupled to the first output pin and the second output pin. The auxiliary coil 322 is coupled to the auxiliary pin. The auxiliary coil 322 is used to determine a commutation time point. The motor system 3 determines the commutation time point according to the voltage of the auxiliary pin. Specifically, the motor system 3 detects the position of the rotor 300 and determines the commutation time point by detecting the voltage zero point of the auxiliary pin. When the single-phase brushless DC motor is in the starting state, the motor system 3 can use the auxiliary coil 322 to determine the commutation time point. When the single-phase brushless DC motor is in a normal operation state, the motor system 3 can also use the auxiliary coil 322 to determine the commutation time point. In addition, the motor system 3 can replace the Hall sensing element by setting the auxiliary coil 322 to determine the commutation time point to reduce the volume and cost of the motor system 3 .

While the present invention has been described by way of illustration of the preferred embodiments, it should be understood that the present invention is not limited to the disclosed embodiments. On the contrary, the present invention is intended to cover various modifications and similar arrangements apparent to those skilled in the art. Accordingly, the scope of the patent application should be accorded the broadest interpretation so as 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 module 100: Rotor N: magnetic pole S: Magnetic pole 110: Stator 120: Winding 1: Motor system 20: Motor Controller HB: endpoint HALL1: endpoint HALL2: Endpoint 200: Hall sensing element IVCC: Supply current 30: Motor module 300: Rotor 310: Stator 40: Motor Controller VCC: endpoint GND: endpoint O1: first endpoint O2: Second endpoint AUX1: First auxiliary endpoint AUX2: Second Auxiliary Endpoint 320: Winding 321: main coil 322: Auxiliary coil 3: Motor system 400: switch circuit 410: Control Unit 420: Current detection unit 430: Voltage detection unit Vd1: The first detection signal Vd2: The second detection signal 401: first transistor 402: Second transistor 403: The third transistor 404: Fourth transistor C1: The first control signal C2: The second control signal C3: The third control signal C4: Fourth control signal T1-T4: commutation time point

FIG. 1 is a schematic diagram of a conventional motor module. FIG. 2 is a schematic diagram of a conventional motor system. FIG. 3 is a timing diagram corresponding to the correlation signal of FIG. 2 . FIG. 4 is a schematic diagram of a motor module according to an embodiment of the present invention. FIG. 5 is a schematic diagram of a motor controller and windings according to an embodiment of the present invention. FIG. 6 is a schematic diagram of a motor system according to an embodiment of the present invention. FIG. 7 is a timing diagram of an embodiment of the present invention.

40: Motor Controller

VCC: endpoint

GND: endpoint

O1: first endpoint

O2: Second endpoint

AUX1: First auxiliary endpoint

AUX2: Second Auxiliary Endpoint

320: Winding

321: main coil

322: Auxiliary coil

Claims (19)

A motor system includes: a first output pin; a second output pin; an auxiliary foot; a main coil, coupled to the first output pin and the second output pin; an auxiliary coil coupled to the auxiliary pin; and A stator, wherein both the main coil and the auxiliary coil are wound on the stator, and the auxiliary coil is used to determine a commutation time point. The motor system as described in claim 1, wherein the motor system determines the commutation time point according to a voltage of the auxiliary pin. The motor system of claim 1, wherein the motor system determines the commutation time point by detecting a voltage zero point of the auxiliary pin. The motor system of claim 1, wherein the motor system further comprises a rotor, and the motor system detects a position of the rotor by detecting a voltage zero point of the auxiliary pin. The motor system of claim 1, wherein the main coil has a first number of turns N1, and the auxiliary coil has a second number of turns N2, wherein N1/N2≥1. The motor system of claim 1, wherein the motor system is applied to a single-phase brushless DC motor. The motor system of claim 1, wherein the auxiliary coil is coupled to the first output pin or the second output pin. The motor system of claim 1, wherein the auxiliary coil is coupled to a reference voltage. A motor system includes: a first endpoint; a second endpoint; a first auxiliary endpoint; a rotor; a main coil, coupled to the first terminal and the second terminal; an auxiliary coil, coupled to the first auxiliary terminal; a stator, wherein both the main coil and the auxiliary coil are wound on the stator; a switch circuit for providing a driving current to the main coil; and A control unit is used for generating a plurality of control signals to control the switch circuit, wherein the auxiliary coil is used for determining a commutation time point. The motor system of claim 9, wherein the motor system determines the commutation time point according to a voltage of the first auxiliary terminal. The motor system as described in claim 9, wherein the motor system determines the commutation time point by detecting a voltage zero point of the first auxiliary terminal. The motor system as described in claim 9, wherein the motor system determines the commutation time point by detecting a zero point of the driving current. The motor system of claim 9, wherein the motor system determines the commutation time point by detecting a voltage zero point of the first auxiliary terminal and detecting a zero point of the driving current. The motor system of claim 9, wherein the motor system detects a position of the rotor by detecting a voltage zero point of the first auxiliary terminal. The motor system of claim 9, wherein the main coil has a first number of turns N1, and the auxiliary coil has a second number of turns N2, wherein N1/N2≥1. The motor system as described in claim 9, wherein the motor system further comprises: a current detection unit for detecting a zero point of the driving current; and a voltage detection unit for detecting a voltage zero point of the first auxiliary terminal. The motor system of claim 9, wherein the motor system is applied to a single-phase brushless DC motor. The motor system of claim 9, wherein the auxiliary coil is coupled to the first terminal or the second terminal. The motor system of claim 9, wherein the auxiliary coil is coupled to a reference voltage.

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