Methods and control apparatus for operating a three-phase electric motor are described, in which the motor windings are switched between Star and Delta connections depending on torque requirements, and in which the motor windings are switched to a braking mode when braking torque is required. The electromagnetic torque of the motor is monitored, and a command to switch from Star to Delta is given when the electromagnetic torque rises to reach or exceed a threshold.

An electric machine includes a rotor and a stator. The stator includes a stator core having a plurality of slots. The stator further includes a plurality of drive modules configured to collectively produce an aggregate rotating magnetic field. Each respective drive module includes a power supply configured to generate a respective poly-phase alternating current (AC) output and is connected to a plurality of respective conductor windings. Each respective conductor winding includes a plurality of respective conductors, each respective conductor configured to carry a respective phase of the respective poly-phase AC output. Each respective drive module is configured to generate a rotating, poly-phase, multipole magnetic field. The rotating, poly-phase, multipole magnetic field is a superimposition of a plurality of respective mono-phase, multiple magnetic fields being generated by a respective conductor of the respective conductor winding.

A power supply device includes connector from a power source, a rectifying module, a power supply module, and a bulk capacitor. The capacitor stores and smoothes the rectified power, and outputs the smoothed power to the power supply module. The connector is capable of connecting to the power source through a Delta connection and a Wye connection.

A power supply device includes connector from a power source, a rectifying module, a power supply module, and a bulk capacitor. The capacitor stores and smoothes the rectified power, and outputs the smoothed power to the power supply module. The connector is capable of connecting to the power source through a Delta connection and a Wye connection.

A method is provided for operating a rotating field machine of a motor vehicle, wherein at least two winding systems of the rotating field machine are supplied with current from an intermediate circuit via a transmission device having at least two switching units and wherein respective switching sequences for the switching units for supplying the winding system in question are defined. For the switching sequences, first switching states in which current is drawn from the intermediate circuit and second switching states in which no current is drawn are defined. The first switching states of the respective switching sequences are defined so as to be free of overlap. For at least one of the switching sequences, third switching states are defined, in which current is fed into the intermediate circuit. The third switching states are defined so as to overlap with the first switching states of the other switching sequence.

A driving device drives a motor having coils. The driving device includes a connection switching unit to switch a connection state of the coils, a temperature sensor to detect a room temperature, and a controller to switch the connection state of the coils based on a detected temperature by the temperature sensor.

Driver circuits are provided in correspondence to switching elements of an inverter to output gate signals to the switching elements and built in an IC package in an abnormality detection device (ECU). Motor relays are provided in motor current paths between inter-arm connection points and multi-phase motor windings. Pull-up resistors connect a power supply line and the inter-arm connection points. Pull-down resistors connect the inter-arm connection points and the ground. A checking unit acquires a voltage corresponding to a voltage of each inter-arm connection point as a terminal voltage and checks a short-circuit failure or an open-circuit failure of each motor relay or a disconnection failure of each winding based on the terminal voltage. The pull-up resistors and the pull-down resistors are provided within the IC package in which the driver circuits are built.

An air conditioner includes a signal receiving unit to receive an operation instruction signal, a compressor including a motor including coils, an inverter connected to the coils, a connection switching unit to switch a connection state of the coils between a first connection state and a second connection state, and a controller to control the inverter and the connection switching unit. When the signal receiving unit receives an operation stop signal, the connection switching unit switches the connection state of the coils from the first connection state to the second connection state.

An air conditioner includes a signal receiving unit to receive an operation instruction signal, a compressor including a motor including coils, an inverter connected to the coils, a connection switching unit to switch a connection state of the coils between a first connection state and a second connection state, and a controller to control the inverter and the connection switching unit. When the signal receiving unit receives an operation stop signal, the connection switching unit switches the connection state of the coils from the first connection state to the second connection state.

An electric-motor driving device includes an inverter connected to terminals connected to windings of an electric motor including the windings, the inverter applying an alternating-current voltage to the electric motor, a switching unit connected to the terminals and capable of switching a connection state between the terminals, a detecting unit that detects at least one of a voltage and an electric current of the inverter, and a control unit that determines on the basis of a detection value detected by the detecting unit that an abnormality occurs in the switching unit and controls the inverter to short-circuit at least two of the terminals.