Method, controller, and power converter for controlling a single-switch based switched reluctance machine
View Patent ↗A method for controlling a multi-phase motor includes withholding energization of a first phase of the motor for a non-zero period when the first phase's dwell time begins. Energization of the first phase is activated upon the expiration of the non-zero period. Energization of the first phase is deactivated for the remainder of the dwell time at a deactivation time occurring before or at the expiration of the dwell time.
1. A method for controlling a multi-phase motor, the method comprising:
withholding energization of a first phase of the motor for a non-zero period when the first phase's dwell time begins;
activating the energization of the first phase upon the expiration of the non-zero period; and
deactivating the energization of the first phase for the remainder of the dwell time at a deactivation time occurring before or at the expiration of the dwell time, wherein
the dwell time of the first phase is the period during which the change of inductance is positive within a motor winding of the first phase.
2. The method of claim 1 , wherein the energization of the first phase is activated and deactivated only once in the dwell time.
3. The method of claim 1 , wherein the energization of the first phase is activated and deactivated multiple times in the dwell time.
4. The method of claim 1 , further comprising applying energy stored by the first phase during its energization to energize a second phase of the motor upon deactivating the energization of the first phase.
5. The method of claim 4 , further comprising:
determining the time required for the first phase to de-energize; and
setting the deactivation time based on the expiration of the dwell time and the determined time for de-energizing the first phase.
6. The method of claim 5 , wherein the deactivation time precedes the expiration of the dwell time by no more than the determined time for de-energizing the first phase.
7. The method of claim 4 , wherein the deactivation time is set to prevent the generation of negative motoring torque in the second phase due the application of energy stored in the first phase to the second phase.
8. The method of claim 7 , wherein the deactivation time is set to prevent the generation of negative motoring torque in the first phase.
9. The method of claim 4 , wherein the second phase is passively energized by the de-energization of the first phase.
10. The method of claim 9 , wherein only the second phase is passively energized by the de-energization of another motor phase.
11. The method of claim 7 , wherein:
the second phase is passively energized by the de-energization of the first phase, and
only the second phase is passively energized by the de-energization of another motor phase.
12. The method of claim 1 , further comprising:
determining a requested torque for rotating a load of the motor; and
setting, based on the deactivation time, an activation time for activating the energization of the first phase so as to generate the requested torque with the first phase within the dwell time.
13. The method of claim 12 , wherein the activation time is set based on the magnitude of current to be applied in energizing the first phase during the dwell time and an estimated current magnitude applied over the entire dwell time to achieve the same amount of energization.
14. The method of claim 12 , further comprising:
determining the rotational speed of a rotor of the motor, wherein
the activation time is set based on the determined rotational speed of the rotor.
15. The method of claim 13 , wherein the activation time is set based on a current to be applied in energizing phase A, the resistance of the motor's stator for phase A, and a voltage drop of a regulator that activates and de-activates the energization of phase A.
16. A controller for a multi-phase motor, the controller comprising:
a processor that:
determines the dwell time of a first phase of the motor,
withholds a signal for energizing the first phase of the motor for a non-zero period when the first phase's dwell time begins,
outputs the signal for energizing the first phase upon the expiration of the non-zero period, and
withdraws the signal for energizing the first phase for the remainder of the dwell time at a deactivation time occurring before or at the expiration of the dwell time; and
a regulator that regulates the energization of the first phase in accordance with the energization signal, wherein
the dwell time of the first phase is the period during which the change of inductance is positive within a motor winding of the first phase.
17. The controller of claim 16 , wherein the processor outputs and withdraws the energization signal only once in the dwell time.
18. The controller of claim 16 , wherein the processor outputs and withdraws the energization signal multiple times in the dwell time.
19. The controller of claim 16 , wherein the processor determines the rotational speed of a rotor of the motor and outputs the energization signal at a time based on the determined rotational speed so as to apply a desired torque to the rotor.
20. The controller of claim 16 , wherein, so as to apply a desired torque to a rotor of the motor, the processor outputs the energization signal at a time based on a current to be applied in energizing phase A, the resistance of the motor's stator for phase A, and a voltage drop of a regulator that activates and de-activates the energization of phase A.
21. A power converter for a multi-phase motor, the power converter comprising:
a processor that:
determines the dwell time of a first phase of the motor,
withholds a signal for energizing the first phase of the motor for a non-zero period when the first phase's dwell time begins,
outputs the signal for energizing the first phase upon the expiration of the non-zero period, and
withdraws the signal for energizing the first phase for the remainder of the dwell time at a deactivation time occurring before or at the expiration of the dwell time; and
a regulator that regulates the energization of the first phase in accordance with the energization signal, wherein:
energy stored by the first phase during its energization is applied to energizing a second phase of the motor upon the withdrawal of the energization signal, and
the dwell time of the first phase is the period during which the change of inductance is positive within a motor winding of the first phase.
22. The power converter of claim 21 , wherein the processor determines the time required for the first phase to de-energize and sets the deactivation time based on the expiration of the dwell time and the determined time for de-energizing the first phase.
23. The power converter of claim 22 , wherein the processor sets the deactivation time to precede the expiration of the dwell time by no more than the determined time for de-energizing the first phase.
24. The power converter of claim 21 , wherein the processor determines a requested torque for rotating a load of the motor and outputs, based on the deactivation time, the energization signal at a time so as to generate the requested torque with the first phase within the dwell time.
25. The power converter of claim 21 , wherein the processor sets the deactivation time to prevent the generation of negative motoring torque in the second phase due the application of energy stored in the first phase to the second phase.
26. The power converter of claim 25 wherein the processor sets the deactivation time to prevent the generation of negative motoring torque in the first phase.
27. The power converter of claim 25 , wherein:
the second phase is passively energized by the de-energization of the first phase, and
only the second phase is passively energized by the de-energization of another motor phase.
28. The power converter of claim 21 , wherein the second phase is passively energized by the de-energization of the first phase.
29. The power converter of claim 28 , wherein only the second phase is passively energized by the de-energization of another motor phase.
30. The power converter of claim 21 , wherein the processor outputs the energization signal at a time based on the magnitude of current to be applied in energizing the first phase during the dwell time and an estimated current magnitude applied over the entire dwell time to achieve the same amount of energization.
31. The power converter of claim 21 , wherein the processor determines the rotational speed of a rotor of the motor and outputs the energization signal at a time based on the determined rotational speed of the rotor so as to apply a desired torque to the rotor.
32. The power converter of claim 21 , wherein, so as to apply a desired torque to a rotor of the motor, the processor outputs the energization signal at a time based on a current to be applied in energizing phase A, the resistance of the motor's stator for phase A, and a voltage drop of a regulator that activates and de-activates the energization of phase A.