Motor controller

Abstract

A motor controller is used to stabilize motor current. The motor controller is used to drive a motor. The motor controller includes a switching circuit, a control unit, and a phase detection unit. The phase detection unit generates a phase signal to the control unit to switch the phase. The phase signal is sequentially generated in first to sixth time intervals. The first to sixth time intervals correspond to the first to sixth phases, respectively. The motor controller further includes a first drive time for driving the motor in the fifth phase, wherein the first drive time is related to the first time interval. The motor controller further includes a second drive time for driving the motor in the sixth phase, wherein the second drive time is related to the second time interval.

Description

Technical Field

[0001] The present invention relates to a motor controller, and more particularly to a motor controller capable of stabilizing motor current. Background Art

[0002] Generally speaking, stabilizing motor current and speed is a goal. The motor rotor is divided into multiple magnetic pole regions. A motor controller detects these regions to switch phases and drive the motor. However, when the sizes of the multiple magnetic pole regions vary due to manufacturing tolerances, existing methods can increase the ratio of high and low current in each phase, making the motor speed unstable. Summary of the Invention

[0003] In view of the aforementioned problems, an object of the present invention is to provide a motor controller for stabilizing the current of a motor.

[0004] According to the present invention, a motor controller is provided. The motor controller is used to drive a motor, wherein the motor has a motor coil and a rotor. The rotor has a first magnetic pole region, a second magnetic pole region, a third magnetic pole region, and a fourth magnetic pole region for switching phases. The motor coil has a first terminal and a second terminal. The motor controller has a switching circuit, a control unit, and a phase detection unit. The switching circuit has a first transistor, a second transistor, a third transistor, and a fourth transistor for providing the motor current to the motor coil. The control unit generates a plurality of control signals to control the switching circuit. The phase detection unit generates a phase signal to the control unit for switching phases, wherein the phase detection unit can be a Hall sensor element or a back electromotive force detection circuit.

[0005] The phase signal sequentially generates a first time interval T01, a second time interval T02, a third time interval T03, a fourth time interval T04, a fifth time interval T05, a sixth time interval T06, a seventh time interval T07, and an eighth time interval T08. The first time interval T01 corresponds to a first phase and the first magnetic pole region. The second time interval T02 corresponds to a second phase and the second magnetic pole region. The third time interval T03 corresponds to a third phase and the third magnetic pole region. The fourth time interval T04 corresponds to a fourth phase and the fourth magnetic pole region. The fifth time interval T05 corresponds to a fifth phase and the first magnetic pole region. The sixth time interval T06 corresponds to a sixth phase and the second magnetic pole region. The seventh time interval T07 corresponds to a seventh phase and the third magnetic pole region. The eighth time interval T08 corresponds to an eighth phase and the fourth magnetic pole region. The motor controller uses the phase signal to cause the rotor to rotate 360 degrees in a first cycle to complete a first revolution, wherein the first cycle is equal to (T01+T02+T03+T04). Next, the motor controller uses the phase signal to cause the rotor to rotate 360 degrees in a second cycle to complete a second revolution, wherein the second cycle is equal to (T05+T06+T07+T08). The control unit can record the first time interval T01, the second time interval T02, the third time interval T03, and the fourth time interval T04 for use in the second revolution. The control unit can also record the fifth time interval T05, the sixth time interval T06, the seventh time interval T07, and the eighth time interval T08 for use in the third revolution.

[0006] The motor controller further has a first drive time for driving the motor during the fifth phase, wherein the first drive time is related to the first time interval T01. The motor controller further has a second drive time for driving the motor during the sixth phase, wherein the second drive time is related to the second time interval T02. The motor controller further has a third drive time for driving the motor during the seventh phase, wherein the third drive time is related to the third time interval T03. The motor controller further has a fourth drive time for driving the motor during the eighth phase, wherein the fourth drive time is related to the fourth time interval T04. In other words, starting from the second rotation, the drive time of each phase is related to the time interval corresponding to the same magnetic pole region in the previous rotation. Based on the above rules, the motor controller can stabilize the motor current and reduce the difference in motor speed between the front and rear rotations when the magnetic pole regions are asymmetric. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 FIG. 1 is a schematic diagram of a motor controller according to an embodiment of the present invention.

[0008] Figure 2 FIG. 1 is a schematic diagram of a rotor according to an embodiment of the present invention.

[0009] Figure 3 is a timing diagram of an embodiment of the present invention.

[0010] List of reference numerals: 10-motor controller; 100-switching circuit; 110-control unit; 120-phase detection unit; 101-first transistor; 102-second transistor; 103-third transistor; 104-fourth transistor; VCC-voltage source; GND-ground potential; L-motor coil; O1-first terminal; O2-second terminal; IL-motor current; C1-first control signal; C2-second control signal; C3-third control signal; C4-fourth control signal; Vph-phase signal; N1-first magnetic pole region; S1-second magnetic pole region; N2-third magnetic pole region; S2-fourth magnetic pole region; T01-first time interval; T02-second time interval; T03-third time interval; T04-fourth time interval; T05-fifth time interval; T06-sixth time interval; T07-seventh time interval; T08-eighth time interval; T1-first cycle; T2-second cycle. DETAILED DESCRIPTION

[0011] The following description will make the purpose, features, and advantages of the present invention more apparent.Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0012] Figure 1 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 having a motor coil L and a rotor. Figure 2 Schematic diagram of a rotor according to an embodiment of the present invention. The rotor has a first magnetic pole region N1, a second magnetic pole region S1, a third magnetic pole region N2, and a fourth magnetic pole region S2 for switching phases. Ideally, the first magnetic pole region N1, the second magnetic pole region S1, the third magnetic pole region N2, and the fourth magnetic pole region S2 should each occupy a quarter of the rotor. Figure 2 As shown, due to errors in the actual manufacturing process, the sizes of the first magnetic pole region N1 , the second magnetic pole region S1 , the third magnetic pole region N2 , and the fourth magnetic pole region S2 do not each occupy a quarter of the rotor.

[0013] The motor coil L has a first terminal O1 and a second terminal O2. The motor controller 10 has a switching circuit 100, a control unit 110, and a phase detection unit 120. The switching circuit 100 has a first transistor 101, a second transistor 102, a third transistor 103, and a fourth transistor 104 for providing a motor current IL to the motor coil L. The first transistor 101 is coupled to a voltage source VCC and the first terminal O1, and the second transistor 102 is coupled to the first terminal O1 and a ground potential GND. The third transistor 103 is coupled to the voltage source VCC and the second terminal O2, and the fourth transistor 104 is coupled to the second terminal O2 and the ground potential GND. The first transistor 101, the second transistor 102, the third transistor 103, and the fourth transistor 104 can be a P-type metal oxide semiconductor transistor or an N-type metal oxide semiconductor transistor. Figure 1 In the embodiment, the first transistor 101 and the third transistor 103 are two P-type metal oxide semiconductor transistors, and the second transistor 102 and the fourth transistor 104 are two N-type metal oxide semiconductor transistors.

[0014] The control unit 110 generates a first control signal C1, a second control signal C2, a third control signal C3, and a fourth control signal C4 to control the switching states of the first transistor 101, the second transistor 102, the third transistor 103, and the fourth transistor 104, respectively. The phase detection unit 120 generates a phase signal Vph to the control unit 110 to switch the phase. The phase detection unit 120 can be a Hall sensor or a back-electromotive force detection circuit. For example, the Hall sensor can be used to sense the position changes of the rotor in the first magnetic pole region N1, the second magnetic pole region S1, the third magnetic pole region N2, and the fourth magnetic pole region S2 to generate the phase signal Vph. Therefore, the phase signal Vph can be used to determine the current phase of the rotor in the first magnetic pole region N1, the second magnetic pole region S1, the third magnetic pole region N2, and the fourth magnetic pole region S2. The control unit 110 receives the phase signal Vph to drive the motor.

[0015] Figure 3This is a timing diagram of an embodiment of the present invention. Phase signal Vph sequentially generates a first time interval T01, a second time interval T02, a third time interval T03, a fourth time interval T04, a fifth time interval T05, a sixth time interval T06, a seventh time interval T07, and an eighth time interval T08. The first time interval T01 corresponds to a first phase and the first magnetic pole region N1. The second time interval T02 corresponds to a second phase and the second magnetic pole region S1. The third time interval T03 corresponds to a third phase and the third magnetic pole region N2. The fourth time interval T04 corresponds to a fourth phase and the fourth magnetic pole region S2. The fifth time interval T05 corresponds to a fifth phase and the first magnetic pole region N1. The sixth time interval T06 corresponds to a sixth phase and the second magnetic pole region S1. The seventh time interval T07 corresponds to a seventh phase and the third magnetic pole region N2. The eighth time interval T08 corresponds to an eighth phase and the fourth magnetic pole region S2. The motor controller 10 uses the phase signal Vph to cause the rotor to rotate 360 degrees in a first period T1 to complete a first revolution, where the first period T1 is equal to (T01+T02+T03+T04). Next, the motor controller 10 uses the phase signal Vph to cause the rotor to rotate 360 degrees in a second period T2 to complete a second revolution, where the second period T2 is equal to (T05+T06+T07+T08). The control unit 110 can record the first time interval T01, the second time interval T02, the third time interval T03, and the fourth time interval T04 for use in the second revolution. The control unit 110 can also record the fifth time interval T05, the sixth time interval T06, the seventh time interval T07, and the eighth time interval T08 for use in the third revolution.

[0016] Specifically, the motor controller 10 further has a first driving time to drive the motor in the fifth phase, wherein the first driving time is related to the first time interval T01. The motor controller 10 further has a second driving time to drive the motor in the sixth phase, wherein the second driving time is related to the second time interval T02. The motor controller 10 further has a third driving time to drive the motor in the seventh phase, wherein the third driving time is related to the third time interval T03. The motor controller 10 further has a fourth driving time to drive the motor in the eighth phase, wherein the fourth driving time is related to the fourth time interval T04. That is, starting from the second circle, the driving time of each phase is related to the time interval corresponding to the same magnetic pole region in the previous circle. According to the above rules, there are at least three implementation methods that can stabilize the motor current IL and reduce the difference in motor speed between the front and rear circles when the magnetic pole regions are asymmetric:

[0017] 1. The first driving time is equal to T01. The second driving time is equal to T02. The third driving time is equal to T03. The fourth driving time is equal to T04. Subsequent driving times are deduced in the same manner.

[0018] 2. The first driving time is equal to (T01+T02+T03+T04) / 4. The second driving time is equal to (T01+T02+T03+T04) / 4. The third driving time is equal to (T01+T02+T03+T04) / 4. The fourth driving time is equal to (T01+T02+T03+T04) / 4. Subsequent driving times are deduced in the same manner.

[0019] 3. The first driving time is equal to (T01+T02+T03+T04) / 4. The second driving time is equal to (T02+T03+T04+T05) / 4. The third driving time is equal to (T03+T04+T05+T06) / 4. The fourth driving time is equal to (T04+T05+T06+T07) / 4. Subsequent driving times are deduced in the same manner.

[0020] A motor controller 10 according to one embodiment of the present invention can be applied to a single-phase motor. When the motor controller 10 is operating in the (M+1)th revolution, the driving time of the phase corresponding to the first magnetic pole region N1 is correlated with the time interval corresponding to the first magnetic pole region N1 in the Mth revolution, where M is a positive integer and M≥1. When the motor controller 10 is operating in the (M+1)th revolution, the driving time of the phase corresponding to the second magnetic pole region S1 is correlated with the time interval corresponding to the second magnetic pole region S1 in the Mth revolution. When the motor controller 10 is operating in the (M+1)th revolution, the driving time of the phase corresponding to the third magnetic pole region N2 is correlated with the time interval corresponding to the third magnetic pole region N2 in the Mth revolution. When the motor controller 10 is operating in the (M+1)th revolution, the driving time of the phase corresponding to the fourth magnetic pole region S2 is correlated with the time interval corresponding to the fourth magnetic pole region S2 in the Mth revolution. Therefore, the motor controller 10 can reduce the high-low ratio of the motor current IL in each phase and reduce the difference in motor speed between the Mth revolution and the (M+1)th revolution.

[0021] While the present invention has been described with reference to 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 that are apparent to those skilled in the art. Therefore, the scope of the claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.

[0022] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A motor controller for driving a motor having a motor coil having a first terminal and a second terminal, wherein: The motor controller includes: a switching circuit for providing a motor current to the motor coil; a control unit for generating a plurality of control signals to control the switch circuit; a phase detection unit for generating a phase signal to the control unit, wherein the phase signal sequentially generates a first time interval (T01), a second time interval (T02), a third time interval (T03), a fourth time interval (T04), a fifth time interval (T05), and a sixth time interval (T06), the first time interval (T01) corresponding to a first phase, the second time interval (T02) corresponding to a second phase, the third time interval (T03) corresponding to a third phase, the fourth time interval (T04) corresponding to a fourth phase, the fifth time interval (T05) corresponding to a fifth phase, and the sixth time interval (T06) corresponding to a sixth phase; and a first driving time for driving the motor during the fifth phase, wherein the first driving time is related to the first time interval (T01); wherein the control unit records the first time interval (T01), the second time interval (T02), the third time interval (T03), the fourth time interval (T04), the fifth time interval (T05), and the sixth time interval (T06) to drive the motor; The motor controller is used to reduce a high-low ratio of the motor current in the phase.

2. The motor controller according to claim 1, characterized in that The first driving time is equal to the first time interval (T01).

3. The motor controller according to claim 1, wherein: The first driving time is equal to (T01+T02+T03+T04) / 4.

4. The motor controller according to claim 1, wherein: The motor controller is applied to a single-phase motor.

5. The motor controller according to claim 1, wherein: The switching circuit includes: a first transistor coupled to a voltage source and the first terminal; a second transistor coupled to the first terminal and a ground potential; a third transistor coupled to the voltage source and the second terminal; and A fourth transistor is coupled to the second terminal and the ground potential.

6. The motor controller according to claim 1, characterized in that The motor controller further includes a second driving time for driving the motor during the sixth phase. The second driving time is related to the second time interval (T02).

7. The motor controller according to claim 6, characterized in that: The second driving time is equal to the second time interval (T02).

8. The motor controller according to claim 6, characterized in that The second driving time is equal to (T01+T02+T03+T04) / 4.

9. The motor controller according to claim 6, characterized in that: The second driving time is equal to (T02+T03+T04+T05) / 4.

10. A motor controller for driving a motor having a motor coil and a rotor having a first magnetic pole region, wherein: The motor controller includes: a switching circuit for providing a motor current to the motor coil; a control unit for generating a plurality of control signals to control the switch circuit; and a phase detection unit for generating a phase signal to the control unit, wherein when the motor controller is operating in an (M+1)th revolution, a driving time of a phase of the first magnetic pole region is correlated to a time interval corresponding to the first magnetic pole region in an Mth revolution, where M is a positive integer and M≥1; The control unit records a first time interval (T01), a second time interval (T02), a third time interval (T03), and a fourth time interval (T04) corresponding to the magnetic pole region of the Mth circle, and a fifth time interval (T05) and a sixth time interval (T06) corresponding to the M+1th magnetic pole region to drive the motor; The motor controller is used to reduce a high-low ratio of the motor current in the phase.

11. The motor controller according to claim 10, characterized in that: The motor controller is used to reduce the difference between the motor speed at the Mth revolution and the (M+1)th revolution.

12. The motor controller according to claim 10, characterized in that The motor controller is applied to a single-phase motor.

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