A control device for a pole-number switching electric motor applied to a system including an electric motor capable of switching a number of poles, and an inverter electrically connected to stator windings of the electric motor; includes: a basic operation unit configured to operate the inverter to control a current amplitude which is magnitude of a current vector flowing in the stator winding, and a switching operation unit configured to operate the inverter to reduce the current amplitude before switching and increase the current amplitude after switching. The switching operation unit, the pole number switching period, operates the inverter so that a total value of the current amplitude before switching and the current amplitude after switching does not exceed a limiting current value.

The present invention relates to an electronic pole changing-based induction motor control system and a control method thereof. Such induction motor control system comprises an induction motor, an inverter and a DC power supply. The inverter is connected with the motor and the DC power supply respectively, for converting a direct current supplied by the DC power supply to an alternating current supplied to the motor. The motor comprises N three-phase windings (11, 12; 31, 32). The inverter comprises N inversion driving units (21, 22; 41, 42) and at least one control unit. Each inversion driving unit is connected with one three-phase winding. The control unit controls the inversion driving unit to generate a current of the three-phase winding connected thereto, and frequency, amplitude and phase of the current can be controlled by the control unit. The control unit alters current directions or phase angles of at least part of the three-phase windings according to a synchronous rotational speed of the motor, making N three-phase windings form at least two pole-pair numbers. The induction motor control system enhances the low-speed torque and broadens the speed governing operation range, thereby enhancing the control accuracy and operation efficiency, and simplifying a peripheral transmission mechanism.

The present invention relates to an electronic pole changing-based induction motor control system and a control method thereof. Such induction motor control system comprises an induction motor, an inverter and a DC power supply. The inverter is connected with the motor and the DC power supply respectively, for converting a direct current supplied by the DC power supply to an alternating current supplied to the motor. The motor comprises N three-phase windings (11, 12; 31, 32). The inverter comprises N inversion driving units (21, 22; 41, 42) and at least one control unit. Each inversion driving unit is connected with one three-phase winding. The control unit controls the inversion driving unit to generate a current of the three-phase winding connected thereto, and frequency, amplitude and phase of the current can be controlled by the control unit. The control unit alters current directions or phase angles of at least part of the three-phase windings according to a synchronous rotational speed of the motor, making N three-phase windings form at least two pole-pair numbers. The induction motor control system enhances the low-speed torque and broadens the speed governing operation range, thereby enhancing the control accuracy and operation efficiency, and simplifying a peripheral transmission mechanism.

A system includes a motor having a plurality of windings, a rotor and a stator magnetically coupled to the rotor, a plurality of power inverters connected to respective windings, wherein the plurality of power inverters is configured to control currents of the plurality of windings, and a controller configured to determine an injection ratio of a high-order harmonic component to a fundamental component based on a performance index, and wherein the injection ratio for a magnetizing component is different from the injection ratio for a torque component at a same harmonic frequency.

A system includes a motor having a plurality of windings, a rotor and a stator magnetically coupled to the rotor, a plurality of power inverters connected to respective windings, wherein the plurality of power inverters is configured to control currents of the plurality of windings, and a controller configured to determine an injection ratio of a high-order harmonic component to a fundamental component based on a performance index, and wherein the injection ratio for a magnetizing component is different from the injection ratio for a torque component at a same harmonic frequency.

Provided is a pole-number-changing rotary electric machine having excellent torque-current characteristics both at a more-pole drive time and at a less-pole drive time without use of a winding changing mechanism. The pole-number-changing rotary electric machine is configured to change a number of poles between the more-pole drive time and the less-pole drive time, and includes: a rotary electric machine including: a stator including stator slots arranged in a mechanical angle direction; and a rotor configured to be rotated by magnetomotive forces generated by currents flowing through stator coils stored in the stator slots; an inverter configured to supply an m-phase current to the stator coils; and a control unit configured to control the inverter, the per-stator-slot magnetomotive forces being arranged at regular angle intervals.

Provided is a pole-number-changing rotary electric machine having excellent torque-current characteristics both at a more-pole drive time and at a less-pole drive time without use of a winding changing mechanism. The pole-number-changing rotary electric machine is configured to change a number of poles between the more-pole drive time and the less-pole drive time, and includes: a rotary electric machine including: a stator including stator slots arranged in a mechanical angle direction; and a rotor configured to be rotated by magnetomotive forces generated by currents flowing through stator coils stored in the stator slots; an inverter configured to supply an m-phase current to the stator coils; and a control unit configured to control the inverter, the per-stator-slot magnetomotive forces being arranged at regular angle intervals.

To provide a controller for an AC rotary machine capable of performing on/off control of the switching device of the set which does not fail, by considering the state of the AC rotary machine related to the windings of the failed set. A controller for an AC rotary machine, about a set in which the switching device failed, stops dq-axis current control, and turns on, in the case of the short circuit failure, and turns off, in the case of the open circuit failure, at least the respective phase switching devices of the positive electrode side or the negative electrode side which is the same side as the failed switching device; and about a set which does not fail, continues dq-axis current control and changes the current component of the d-axis according to the state of the AC rotary machine related to the windings of the failed set.

To provide a controller for an AC rotary machine capable of performing on/off control of the switching device of the set which does not fail, by considering the state of the AC rotary machine related to the windings of the failed set. A controller for an AC rotary machine, about a set in which the switching device failed, stops dq-axis current control, and turns on, in the case of the short circuit failure, and turns off, in the case of the open circuit failure, at least the respective phase switching devices of the positive electrode side or the negative electrode side which is the same side as the failed switching device; and about a set which does not fail, continues dq-axis current control and changes the current component of the d-axis according to the state of the AC rotary machine related to the windings of the failed set.

A system includes a motor having a plurality of windings, a rotor and a stator magnetically coupled to the rotor, a plurality of power inverters connected to respective windings, wherein the plurality of power inverters is configured to control currents of the plurality of windings, and a controller configured to determine an injection ratio of a high-order harmonic component to a fundamental component based on a performance index, and wherein the injection ratio for a magnetizing component is different from the injection ratio for a torque component at a same harmonic frequency.