In a method for detecting a motor phase fault of a motor arrangement, the motor phases of which are connected to a drive circuit having a DC voltage intermediate circuit and an inverter. A motor phase voltage at at least one of the motor phases with respect to a reference potential is captured while the inverter is switched off; and a voltage profile of the captured motor phase voltage is used to determine whether there is a motor phase fault on one of the motor phases of the motor arrangement.

The present disclosure is constructed on the prior art inverter architecture, a pulse code width modulation (PCWM). This is an open loop motor control system without sensing its rotor position. The present disclosure employs a closed loop method to track the optimum efficiency motor operating point directly. A bench load test is conducted to gather information for an AI type control, which includes both load angle vs. voltage command charts and power factor vs. voltage command charts, with load levels as parameters for certain frequency command ranges. This way, the optimum efficiency motor operating points are generated a priori. The AI type control is mechanized to track the optimum efficiency motor operating points.

A method for controlling an electronic switching unit for supplying electric power to an inductive power load, includes the following steps: activating an initial filter capacitor by connecting it between the electric power supply of the electronic unit and ground, and deactivating the other capacitors of the bank of filter capacitors; measuring the current flowing through this initial filter capacitor; if this current is above a predetermined nominal current threshold, activating an additional filter capacitor by connecting it between the electric power supply of the electronic unit and ground, in parallel with the initial filter capacitor.

The present disclosure discloses a power transforming apparatus capable of reducing a stress of a converter switch during a PFC operation, an operation method thereof, and an air conditioner including the same. To this end, the power transforming apparatus according to the present disclosure may determine the number of converters for performing a PFC operation based on a magnitude of input power and a speed of the motor. Furthermore, target converter channels are arbitrarily selected using a random function at an initial stage of a PFC operation so as not to add a stress to a switch device of any one converter. In addition, in order to disperse a stress to all switches, phases are individually controlled to perform switching operations while changing converters that match the number of converters for performing a PFC operation in a preset cycle, for example, whenever a zero-crossing is detected.

In other features, a refrigeration system is provided and includes a compressor motor, an inverter, a converter and a control module. The inverter is configured to convert a direct current (DC) bus voltage to an alternating current (AC) voltage and supply the AC voltage to the compressor motor. The converter is configured to convert a DC input voltage to the DC bus voltage. The control module is configured to obtain a parameter and in response to the parameter exceeding a predetermined threshold, reduce the DC bus voltage and at least one of (i) reduce a switching frequency, (ii) increase an amount of negative d-axis current of the compressor motor, or (iii) reduce a speed of the compressor motor.

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.

An electric motor assembly includes a stator, a rotor, a motor housing, a rotatable shaft, a radial fan, and an air scoop. The motor housing at least partly houses the stator and rotor and presents an exterior motor surface. The rotatable shaft is associated with the rotor for rotational movement therewith, with the rotatable shaft extending along a rotational axis. The radial fan is mounted on the rotatable shaft exteriorly of the motor housing and is rotatable with the shaft to direct airflow in a radially outward direction. The air scoop extends radially outwardly relative to the radial fan and axially to receive radial airflow from the radial fan and turn the airflow axially to flow along the exterior motor surface. The air scoop includes spaced apart axially extending airflow vanes to guide the airflow as the airflow is turned axially.

An interleaved bridgeless power factor correction (PFC) converter-based motor drive system is provided. The system includes a first inductor coupled to a second inductor. The coupled first and second inductors are coupled to a first input configured to be coupled to a first line of an alternating current (AC) power supply. The system also includes a third inductor coupled to a fourth inductor. The coupled third and fourth inductors are coupled to a second input configured to be coupled to a second line of the AC power supply. The system further includes a digital active power factor correction (PFC) controller configured to cause current in at least one of the coupled first and second inductors and the coupled third and fourth inductors to be interleaved.

A device for power factor correction can include a converter housing having an inner surface; a first converter substrate mounted on the inner surface of the converter housing; a second converter substrate mounted on another surface of first converter housing opposite to the inner surface; and a housing cover covering the first converter substrate and coupled to an upper surface of the converter housing, in which the second converter substrate includes a first surface having a first region including a source pad, and a second region including a drain pad spaced apart from the source pad, the source pad including a source pad extension portion extending into the second region; and a second surface including a heat dissipation pad for communicating heat from the source and drain pads to an outside of the device, in which the first region of the second converter substrate overlaps with the another surface of first converter housing, and the second region of the second converter substrate faces the housing cover without overlapping with the first converter substrate.

A method and system of subsynchronous oscillations and interactions damping integrated in in a rotor converter based on an adaptive state feedback controller with two spinning vectors, and a Kalman filter whose parameters are optimized by minimizing maximum sensitivity under a constraint of positive damping for a plurality of sensible scenarios is provided. The damping signal generated by the damping module is applied either to a power proportional integer controller or to a current proportional integer controller.