A method and system for operating a hybrid propulsion system, includes controllably providing a first power to a first bus and a first inverter, electrically coupling a first motor with a second inverter by way of a second bus, operably converting, by the second inverter, the first power received by the first inverter to a starting power adapted for starting the first motor, and increasing, by the second inverter, the starting power to match the first power received.

The present disclosure provides a power conversion apparatus converting a power from a DC power source, supplying the converted power to a rotary electric machine to drive the rotary electric machine. The power conversion apparatus according to the present disclosure includes: a first inverter circuit electrically connected to a first end of each of phase winding, transmitting power between respective phase windings and the DC power source; a second inverter circuit electrically connected to a second end each of phase winding, transmitting power between respective phase windings and the DC power source; and a control unit controlling the first inverter circuit and the second inverter circuit. The control unit is configured to change a total amount of current flowing through respective phase windings depending on a rotational speed of the rotary electric machine.

This disclosure relates to refrigerant compressors, and, in particular, relates to cooling for the power electronics of such compressors. An example refrigerant system includes a main refrigerant loop in communication with a condenser, an evaporator, and a compressor. The refrigerant system further includes at least one cooling line configured to direct refrigerant from the main refrigerant loop to cool a chamber containing electronic components. A method is also disclosed.

This disclosure relates to refrigerant compressors, and, in particular, relates to cooling for the power electronics of such compressors. An example refrigerant system includes a main refrigerant loop in communication with a condenser, an evaporator, and a compressor. The refrigerant system further includes at least one cooling line configured to direct refrigerant from the main refrigerant loop to cool a chamber containing electronic components. A method is also disclosed.

A system includes a starter generator configured to provide power to a first bus and a first inverter, a second inverter coupled to the first inverter, a first switch configured to selectively couple the second inverter to the first bus and to a second bus, a second switch configured to selectively couple a first motor to the first bus and to the second bus, and a controller. The controller sets the first switch to a second position and the second switch to a second position, causes the second inverter to convert the power from the first inverter to a starting power for starting the first motor, causes the second inverter to increase the starting power to match the power provided to the first bus from the starter generator, and switches the second switch to the first position, when the starting power matches the power from the starter generator.

Methods and apparatus for open loop startup of a three-phase motor that reduces acoustic noise. During rotor alignment of the motor, there is a maximum level for a phase current to the motor. After the rotor alignment, open loop motor startup is performed during which the phase current has a first slope. At a selected time, such as when a frequency of the phase current reaches a first threshold, the phase current transitions to a second slope.

A control circuit for a motor of a compressor includes an inverter control module configured to control power switching devices of an inverter to generate output voltages from a DC power supply. The output voltages are applied to windings of the motor. A current control module is configured to generate voltage signals based on a torque demand. The inverter control module controls the power switching devices according to the voltage signals. A selector is configured to output one of an open loop torque value and a closed loop torque value as the torque demand. An open loop torque module is configured to generate the open loop torque value. The open loop torque module is configured to apply an upper limit to the open loop torque value. The upper limit is based on a voltage of the DC power supply.

One embodiment describes a wye-delta starter, which includes a first single pole, single current carrying path switching device that selectively connects and disconnects a first winding of a motor in a wye configuration; a second single pole, single current carrying path switching device that selectively connects and disconnects the first winding in a delta configuration, in which the first switching device and the second switching device are coupled via a first interlock; a third single pole, single current carrying path switching device that selectively connects and disconnects a second winding and a third winding of the motor in the wye configuration; a fourth single pole, single current carrying path switching device that selectively connects and disconnects the second winding in the delta configuration, in which the third switching device and the fourth switching device are coupled via a second interlock; and a fifth single pole, single current carrying path switching device that selectively connects and disconnects the third winding in the delta configuration.

One embodiment describes a wye-delta starter, which includes a first single pole, single current carrying path switching device that selectively connects and disconnects a first winding of a motor in a wye configuration; a second single pole, single current carrying path switching device that selectively connects and disconnects the first winding in a delta configuration, in which the first switching device and the second switching device are coupled via a first interlock; a third single pole, single current carrying path switching device that selectively connects and disconnects a second winding and a third winding of the motor in the wye configuration; a fourth single pole, single current carrying path switching device that selectively connects and disconnects the second winding in the delta configuration, in which the third switching device and the fourth switching device are coupled via a second interlock; and a fifth single pole, single current carrying path switching device that selectively connects and disconnects the third winding in the delta configuration.

A motor driving device includes a control unit which outputs a pre-driving signal to control a motor based on command information of an input target number of rotations and detection information of a number of rotations of the motor, and a motor driving unit which drives the motor based on the pre-driving signal. The control unit includes a speed control circuit which outputs speed command information based on the command information of the target number of rotations and the detection information, a stop control circuit which when an input of the command information of the target number of rotations is stopped, outputs stop command information after a predetermined time elapses from detection of stop of the motor, and a driving signal generation circuit which generates a control signal based on the stop command information and the speed command information.