An electric machine includes a stator having a stator winding disposed thereon. A rotor is electromagnetically exposed to the stator. A field winding and an induction winding are disposed on the rotor. A rectifier is electrically coupled to the induction winding and the field winding. Upon application of a voltage to the stator winding, the stator winding produces a first rotating magnetic field and a second rotating magnetic field that has a different spatial frequency than the first rotating magnetic field. The first rotating magnetic field interacts asynchronously with the induction winding to produce an alternating current in the induction winding. The rectifier changes the alternating current to a direct current that is supplied to the field winding. The field winding interacts synchronously with the second rotating magnetic field.

An electric machine includes a stator having a stator winding disposed thereon. A rotor is electromagnetically exposed to the stator. A field winding and an induction winding are disposed on the rotor. A rectifier is electrically coupled to the induction winding and the field winding. Upon application of a voltage to the stator winding, the stator winding produces a first rotating magnetic field and a second rotating magnetic field that has a different spatial frequency than the first rotating magnetic field. The first rotating magnetic field interacts asynchronously with the induction winding to produce an alternating current in the induction winding. The rectifier changes the alternating current to a direct current that is supplied to the field winding. The field winding interacts synchronously with the second rotating magnetic field.

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.

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.

A motor control method includes providing a motor comprising a plurality of windings, a rotor and a stator magnetically coupled to the rotor, coupling a plurality of power converters to the plurality of windings, configuring the plurality of power converters to operate in a first interleaving mode, controlling the plurality of power converters to dynamically adjust the number of poles of the motor and after the step of controlling the plurality of power converters to dynamically adjust the number of poles of the motor, configuring the plurality of power converters to leave the first interleaving mode and enter into a second interleaving mode.

A motor control method includes providing a motor comprising a plurality of windings, a rotor and a stator magnetically coupled to the rotor, coupling a plurality of power converters to the plurality of windings, configuring the plurality of power converters to operate in a first interleaving mode, controlling the plurality of power converters to dynamically adjust the number of poles of the motor and after the step of controlling the plurality of power converters to dynamically adjust the number of poles of the motor, configuring the plurality of power converters to leave the first interleaving mode and enter into a second interleaving mode.

Adjustment of operational performance of an electric machine (e.g., using a computerized tool) is enabled. For example, a non-transitory computer-readable medium can comprise executable instructions that, when executed by a processor, facilitate performance of operations, comprising: deactivating a first sub-set of winding sectors, wherein the first sub-set of the winding sectors comprises at least one winding sector, and triggering an AC drive signal for a second sub-set of the winding sectors such that a rotor is rotated using the winding sectors of the second sub-set, wherein an electric machine comprises a stator and the rotor, wherein the stator comprises a set of N phase windings, wherein each N phase winding, of the set of N phase windings, forms p poles around a circumference of the stator, and wherein each p pole, of the p poles, is formed by the at least one winding sector.

Adjustment of operational performance of an electric machine (e.g., using a computerized tool) is enabled. For example, a non-transitory computer-readable medium can comprise executable instructions that, when executed by a processor, facilitate performance of operations, comprising: deactivating a first sub-set of winding sectors, wherein the first sub-set of the winding sectors comprises at least one winding sector, and triggering an AC drive signal for a second sub-set of the winding sectors such that a rotor is rotated using the winding sectors of the second sub-set, wherein an electric machine comprises a stator and the rotor, wherein the stator comprises a set of N phase windings, wherein each N phase winding, of the set of N phase windings, forms p poles around a circumference of the stator, and wherein each p pole, of the p poles, is formed by the at least one winding sector.

A control apparatus is provided to control a rotating electric machine whose number of poles is switched from a pre-switching number of poles to a post-switching number of poles. The control apparatus includes a pre-switching control unit, a post-switching control unit and a transition control unit. The pre-switching control unit controls the torque generated by the machine before the switching of the number of poles. The post-switching control unit controls the torque generated by the machine after the switching. During a pole-number switching period, the transition control unit controls electric currents flowing in stator coils of the machine or voltages applied to the stator coils to make each magnetic pole formed with control by the pre-switching control unit not coincident with any magnetic pole formed with control by the post-switching control unit and having the same polarity as the magnetic pole formed with the control by the pre-switching control unit.

A control apparatus is provided to control a rotating electric machine whose number of poles is switched from a pre-switching number of poles to a post-switching number of poles. The control apparatus includes a pre-switching control unit, a post-switching control unit and a transition control unit. The pre-switching control unit controls the torque generated by the machine before the switching of the number of poles. The post-switching control unit controls the torque generated by the machine after the switching. During a pole-number switching period, the transition control unit controls electric currents flowing in stator coils of the machine or voltages applied to the stator coils to make each magnetic pole formed with control by the pre-switching control unit not coincident with any magnetic pole formed with control by the post-switching control unit and having the same polarity as the magnetic pole formed with the control by the pre-switching control unit.