A method of detecting a connection fault of an electric motor, applies to a driving mechanism of an inverter, and includes: measuring a three-phase stator current of the electric motor; transforming the three-phase stator current to acquire dual-axis current components in a stationary coordinate; calculating an angle of rotation of the electric motor according to the dual-axis current components; calculating an angular velocity according to the angle of rotation; comparing a frequency of the angular velocity with a frequency of an output voltage of the inverter; and determining that the electric motor occurs a connection fault if a difference between the frequency of the angular velocity and the frequency of the output voltage is greater than a predetermined frequency difference value.

A chiller system includes a compressor, a condenser and an evaporator in fluid communication. A motor drives the compressor. A variable speed drive powers the motor. An oil heater and pump system circulate heated lubricating oil in the compressor. A control panel is arranged to determine whether an input parameter is greater than or equal to a threshold parameter; deactivate the VSD in response to sensing that the input parameter is less than the threshold parameter; determine at least one chiller capacity control parameter at a point when the VSD is deactivated, and maintain the at least one chiller capacity control parameter while the VSD is deactivated; determine that the input parameter has been restored; determine a motor rotation and motor rotational speed; and in response to determining that the input parameter is restored and the motor is rotating in a forward direction, reactivate the VSD.

This application provides a motor drive system, a power system, and an electric vehicle, and relates to the field of power electronic technologies. The drive system is configured to drive a motor that uses a power battery pack as a power supply. The power battery pack includes at least two battery modules that are independent of each other, the drive system includes at least two direct current-alternating current DC-AC circuits, and the battery modules one-to-one correspond to the DC-AC circuits. Each battery module is correspondingly connected to an input end of one DC-AC circuit, and an output end of each DC-AC circuit is connected to a corresponding winding of the motor. The DC-AC circuit is configured to convert a direct current provided by the corresponding battery module into an alternating current to drive the corresponding winding of the motor.

Power supply hold-up time is increased using regenerative braking. A power line disturbance (“PLD”) event is detected in a power supply unit. One or more fan motors associated with the power supply unit may be signaled to provide regenerative braking based on identifying the PLD event, where the one or more fan motors transition from a motor operating mode to a regenerative braking mode. The regenerative braking may be applied to the one or more fan motors associated with the power supply unit, where a hold-up time is extended to prevent shut down of the power supply unit.

A steering angle detection device is provided with a plurality of rotation angle sensors and a plurality of control units. The rotation angle sensors are capable of at least continuously calculating a rotation speed while an ignition switch of a vehicle is turned off, and are provided so as to correspond to steering angle calculation units which calculate steering angle based on the rotation speed and a rotation angle acquired from the rotation angle sensors and midpoint information related to the neutral position of a steering member. Power supplies are provided on a per-system basis. The rotation angle sensors or the control units are capable of holding the midpoint information while the ignition switch is turned off. If a power supply abnormality resulting in power supply failure occurs in some of the systems, the control unit of the abnormal system acquires the midpoint information and the rotation speed from the control unit of a normal system when the ignition switch is turned on.

An air conditioning system including a compressor having a motor; a condenser; an evaporator; a drive providing multiphase, AC output to the motor; a motor braking assembly electrically connected to the drive, the motor braking assembly including at least one switch and at least one braking resistor; wherein the at least one switch is held in an open state by power from the drive; wherein upon disruption of power to the motor, the at least one switch assumes a closed state shorting windings of the motor through the at least one braking resistor.

A main power supply having a large capacity and a backup power supply having a small capacity are switchable by a power supply switching determination unit in a system. A motor control device drives a motor by the main power supply or the backup power supply. A drive control unit outputs a drive signal, calculated by feedback control of the current detection value with respect to the current command value, to an inverter circuit. When the power supply switching determination unit switches from the main power supply to the backup power supply, the drive control unit moves from a normal control using the main power supply to a backup control that restricts an electric power consumption and prevents the backup power supply from stopping.

A power transforming apparatus for supplying power to a motor having a magnetic bearing includes: a converter configured to, in an initial operation, receive AC power, and an auxiliary circuit performing initial charging by rectifying the AC power to a second power and supplying the rectified second power to an inverter controller and a magnetic bearing controller. The inverter controller outputs a signal to an inverter using the second power and controls the inverter to supply a rectified DC voltage to the converter, and the converter is configured to, during a normal operation, stop supplying the second power to the inverter controller and control the rectified DC voltage to be supplied to the inverter controller and the magnetic bearing controller, and, based on a power failure being detected, outputs a control signal such that the second power is supplied to the inverter controller and the magnetic bearing controller.

A motorized window treatment may be configured to adjust a position of a covering material to control the amount of daylight entering a space. The motorized window treatment may include a DC power source for charging an energy storage element, such as a supercapacitor and/or rechargeable battery. The energy storage element may be configured to provide power for the operation of a motor used to adjust the position of the covering material. The energy storage element may discharge when providing power to the motor and may charge such that the current it draws from a battery is at a desired average current level that extends the lifetime of the battery.

The present invention includes an electric distributed propulsion for anti-torque modules for a helicopter and methods of use comprising: two or more generators connected to a main gearbox transmission; at least a first and a second plurality of variable speed motors connected to one or more fixed pitch blades to provide anti-torque thrust connected to the two or more generators, and at least a first and a second yaw control computer independently connected to each of the at least first and second plurality of variable speed motors, wherein each of the first and second yaw control computer serves as a primary and a backup yaw control computer to provide redundant control to both the first and second plurality of variable speed motors.