A drive system includes a three-phase motor having a shaft, a first three-phase stator winding, which is to be connected to a three-phase AC voltage grid, a second three-phase stator winding, which is to be connected to the three-phase AC voltage grid in such a way that a second stator rotating field is produced rotating in opposition with respect to a first stator rotating field, which is generated by the first stator winding, and a rotor winding system which is mechanically coupled in rotationally fixed fashion to the shaft. The drive system further includes at least one inverter, which is mechanically coupled in rotationally fixed fashion to the shaft and which is electrically coupled to the rotor winding system, wherein the at least one inverter is designed to generate actuation signals for the rotor winding system in such a way that a first rotor rotating field and a second rotor rotating field are generated, wherein the first rotor rotating field interacts with the first stator rotating field in such a way that a first motor speed and a first torque are produced, and wherein the second rotor rotating field interacts with the second stator rotating field in such a way that the first motor speed and a second torque are produced, wherein the second torque has an identical direction of action with respect to the first torque.

A drive system includes a three-phase motor having a shaft, a first three-phase stator winding, which is to be connected to a three-phase AC voltage grid, a second three-phase stator winding, which is to be connected to the three-phase AC voltage grid in such a way that a second stator rotating field is produced rotating in opposition with respect to a first stator rotating field, which is generated by the first stator winding, and a rotor winding system which is mechanically coupled in rotationally fixed fashion to the shaft. The drive system further includes at least one inverter, which is mechanically coupled in rotationally fixed fashion to the shaft and which is electrically coupled to the rotor winding system, wherein the at least one inverter is designed to generate actuation signals for the rotor winding system in such a way that a first rotor rotating field and a second rotor rotating field are generated, wherein the first rotor rotating field interacts with the first stator rotating field in such a way that a first motor speed and a first torque are produced, and wherein the second rotor rotating field interacts with the second stator rotating field in such a way that the first motor speed and a second torque are produced, wherein the second torque has an identical direction of action with respect to the first torque.

A motor control system disclosed herein controls operation of a motor having a stator having one of an armature winding and a field winding and a rotor having the other of the armature winding and the field winding. The motor control system includes a first inverter that supplies an armature current to the armature winding, a second inverter that supplies a field current to the field winding, and a control device that controls the operations of the first inverter and the second inverter. The control device is configured to be capable of executing harmonic superimposition processing for at least partially canceling harmonics appearing in the motor by superimposing harmonic currents on the field current based on the motor operation index indicating the operation of the motor.

A motor control system disclosed herein controls operation of a motor having a stator having one of an armature winding and a field winding and a rotor having the other of the armature winding and the field winding. The motor control system includes a first inverter that supplies an armature current to the armature winding, a second inverter that supplies a field current to the field winding, and a control device that controls the operations of the first inverter and the second inverter. The control device is configured to be capable of executing harmonic superimposition processing for at least partially canceling harmonics appearing in the motor by superimposing harmonic currents on the field current based on the motor operation index indicating the operation of the motor.

An apparatus for a drive for an externally excited synchronous machine. The apparatus sets a value for a stator flux linkage reference so as to enable operation in a linear region of a d-axis magnetizing inductance without saturation. The apparatus causes the drive to drive the externally excited synchronous machine with a speed within a linear modulation range using said value. During the driving, the apparatus adjusts a rotor excitation current reference to determine a minimum-load value of a rotor excitation current and causes increasing or decreasing of the rotor excitation current until a stator current is within a pre-defined range. Then, the apparatus determines operating values for the stator and rotor excitation currents and calculates a rotor-to-stator reduction factor based on the minimum-load and operating values of the rotor excitation current, the operating value of the stator current and the value for the stator flux linkage reference.

An apparatus for a drive for an externally excited synchronous machine. The apparatus sets a value for a stator flux linkage reference so as to enable operation in a linear region of a d-axis magnetizing inductance without saturation. The apparatus causes the drive to drive the externally excited synchronous machine with a speed within a linear modulation range using said value. During the driving, the apparatus adjusts a rotor excitation current reference to determine a minimum-load value of a rotor excitation current and causes increasing or decreasing of the rotor excitation current until a stator current is within a pre-defined range. Then, the apparatus determines operating values for the stator and rotor excitation currents and calculates a rotor-to-stator reduction factor based on the minimum-load and operating values of the rotor excitation current, the operating value of the stator current and the value for the stator flux linkage reference.

An electric power control method includes determining whether to change an operation period within which the operating is performed so as to be longer than one cycle of the carrier wave or not; reducing the switching operation of the switching elements in a first half cycle of the carrier wave; changing a slope of the carrier wave in an intermediate period between the first half cycle of the carrier wave and a last half cycle of the carrier wave in the operation period after the change to compare the carrier wave with the duty command value in magnitude; performing the switching operation of the switching elements according to a result of the comparison; and reducing the switching operation of the switching elements in the last half cycle of the carrier wave.

An electric power control method includes determining whether to change an operation period within which the operating is performed so as to be longer than one cycle of the carrier wave or not; reducing the switching operation of the switching elements in a first half cycle of the carrier wave; changing a slope of the carrier wave in an intermediate period between the first half cycle of the carrier wave and a last half cycle of the carrier wave in the operation period after the change to compare the carrier wave with the duty command value in magnitude; performing the switching operation of the switching elements according to a result of the comparison; and reducing the switching operation of the switching elements in the last half cycle of the carrier wave.

A charging system is provided. The charging system includes an inverter, a wound rotor synchronous motor that has at least one stator coil supplied with power converted by the inverter and a rotor having a plurality of field coils, and a switching circuit unit that is configured to selectively supply power to the plurality of field coils. Additionally, a controller is configured to operate the switching circuit unit to supply power from the battery to at least one of the plurality of field coils when the wound rotor synchronous motor operates as a motor and isolate the field coils from the battery and operate the switching circuit unit to supply grid power to a portion of the field coils when the wound rotor synchronous motor is charging when the wound rotor synchronous motor supplies the grid power to the field coil side to charge the battery.

A charging system is provided. The charging system includes an inverter, a wound rotor synchronous motor that has at least one stator coil supplied with power converted by the inverter and a rotor having a plurality of field coils, and a switching circuit unit that is configured to selectively supply power to the plurality of field coils. Additionally, a controller is configured to operate the switching circuit unit to supply power from the battery to at least one of the plurality of field coils when the wound rotor synchronous motor operates as a motor and isolate the field coils from the battery and operate the switching circuit unit to supply grid power to a portion of the field coils when the wound rotor synchronous motor is charging when the wound rotor synchronous motor supplies the grid power to the field coil side to charge the battery.