The invention includes a first power supply connector, which connects a first inverter unit that supplies a drive current to a first three-phase winding of a rotary electric machine to a first vehicle power supply, and a second power supply connector, which connects a first second inverter unit that supplies a drive current to a second three-phase winding of the rotary electric machine to a second vehicle power supply, wherein a voltage of the first vehicle power supply is higher than a voltage of the second vehicle power supply, and a current capacity of the first power supply connector is smaller than a current capacity of the second power supply connector.

A control unit determines a presence or absence of a short-circuit failure with respect to a target switch which is a phase-opening switch to be determined. At this time, after opening all the phase opening switches, the control unit drives an inverter to connect a power supply line provided with the target switch among the phase opening switches to ground. The control unit determines that the target switch has a short-circuit failure when a voltage of the power supply line in which the target switch is not provided is smaller than a predetermined voltage.

A control unit determines a presence or absence of a short-circuit failure with respect to a target switch which is a phase-opening switch to be determined. At this time, after opening all the phase opening switches, the control unit drives an inverter to connect a power supply line provided with the target switch among the phase opening switches to ground. The control unit determines that the target switch has a short-circuit failure when a voltage of the power supply line in which the target switch is not provided is smaller than a predetermined voltage.

In induction motors, efficiency is improved and a maximum torque is increased. For a magnetic flux density of the stator pole for each phase of an induction motor, a circumferential magnetic flux density distribution is controlled to any distribution state, from a trapezoidal wave-like distribution close to a square wave to a sinusoidal distribution. In particular, motor efficiency in a range of low to medium rotations is improved. The motor structure is designed to reduce the leakage inductance of the rotor windings, and the motor and control thereof are optimized for each other. This increases the maximum torque of the motor more effectively. In addition, the high efficiency of the motor makes it possible to reduce the size of the drive circuit.

In induction motors, efficiency is improved and a maximum torque is increased. For a magnetic flux density of the stator pole for each phase of an induction motor, a circumferential magnetic flux density distribution is controlled to any distribution state, from a trapezoidal wave-like distribution close to a square wave to a sinusoidal distribution. In particular, motor efficiency in a range of low to medium rotations is improved. The motor structure is designed to reduce the leakage inductance of the rotor windings, and the motor and control thereof are optimized for each other. This increases the maximum torque of the motor more effectively. In addition, the high efficiency of the motor makes it possible to reduce the size of the drive circuit.

An electric motor system implements a redundant wye-wounded motor that includes first phase leads, second phase leads, first neutral leads, and second neutral leads. The first and second phase leads receive alternating current (AC) power from a power supply. A first phase-lead switch selectively connects the first phase leads to the power supply, and a second phase-lead switch selectively connects the second phase leads to the power supply. A first neutral-lead switch selectively connects the first neutral leads to the redundant wye-wounded motor, and a second neutral-lead switch selectively connects the second neutral leads to the redundant wye-wounded motor. A controller detects a circuit fault among a plurality of different types of circuit faults, and controls the operation of one or both of the primary neutral-lead switch and the second neutral-lead switch based on the circuit fault.

A method of controlling a 3n-phase electrical machine (7) by means of n power converters (3a, 3b) each being controlled by a respective controller, and each power converter (3a, 3b) being configured to power a respective set of three phases of the electrical machine (7), wherein the method for each controller comprises: a) obtaining measured currents (ia,1, ib,1, ic,1, ia,2, ib,2, ic,2) of the set of three phases of the electrical machine (7) controlled by the controller, b) estimating all currents ({circumflex over (.Math.)}dq, 2, {circumflex over (.Math.)}dq, 1) of all the other sets of three phases of the electrical machine (7), which are controlled by the other controllers, c) transforming the measured currents (ia,1, ib,1, ic,1, ia,2, ib,2, ic,2) and all the estimated currents ({circumflex over (.Math.)}dq,2, {circumflex over (.Math.)}dq,1) using vector space decomposition, VSD, to obtain a set of VSD currents, and d) controlling the corresponding power converter based on the VSD currents.

A method of controlling a 3n-phase electrical machine (7) by means of n power converters (3a, 3b) each being controlled by a respective controller, and each power converter (3a, 3b) being configured to power a respective set of three phases of the electrical machine (7), wherein the method for each controller comprises: a) obtaining measured currents (ia,1, ib,1, ic,1, ia,2, ib,2, ic,2) of the set of three phases of the electrical machine (7) controlled by the controller, b) estimating all currents ({circumflex over (.Math.)}dq, 2, {circumflex over (.Math.)}dq, 1) of all the other sets of three phases of the electrical machine (7), which are controlled by the other controllers, c) transforming the measured currents (ia,1, ib,1, ic,1, ia,2, ib,2, ic,2) and all the estimated currents ({circumflex over (.Math.)}dq,2, {circumflex over (.Math.)}dq,1) using vector space decomposition, VSD, to obtain a set of VSD currents, and d) controlling the corresponding power converter based on the VSD currents.

A dual-wound machine comprises a dual-wound generator supplying power to two separate powered zones. The generator comprises a wound rotor with a field winding and a stator with two sets of phase windings and a field control loop that controls the excitation voltage applied to the field winding and therefore the magnetic field produced by the rotor, in order to maintain a constant field flux in the generator and mitigate dynamic coupling between the two sets of phase windings when supplying power to unbalanced loads.

To provide a motor controller which can suppress occurrence of a torque difference between systems, even if a DC voltage difference occurs between systems, in the case where each system is provided with a DC power source. A motor controller is provided with a first controller that controls so that the first q-axis current detection value approaches the second q-axis current detection value or the second q-axis current command value obtained from the second controller, when determining that the first DC voltage is higher than the second DC voltage; and a second controller that controls so that the second q-axis current detection value approaches the first q-axis current detection value or the first q-axis current command value obtained from the first controller, when determining that the second DC voltage is higher than the first DC voltage.