DEVICE TO CONTROL EXCITATION OF AC MOTOR Russian patent published in 2014 - IPC H02H7/08 H02H7/122 H02P27/06 B60L3/04 

FIELD: electricity.

SUBSTANCE: device to control excitation of an AC motor including: an inverter (INV), having multiple switched elements exposed to control by connection/disconnection, to convert DC voltage into AC voltage with required frequency, in order to excite an AC motor (6); an opening contactor (MMK) of the motor connected between the inverter (INY) and the AC motor (6); a unit (55) of preliminary detection of a switching operation for detection of the switching operation of the opening contactor (MMK) of the motor to the contact or disconnection of the main contacts and release of a signal of preliminary detection of the switching operation; and a control unit (10A), comprising a unit (70) of inverter control for control of connection/disconnection for multiple switching elements and control of disconnection for an opening contactor (MMK) of the motor and control of the inverter (INV) on the basis of the signal of preliminary detection of the switching operation.

EFFECT: result consists in prevention of generation of hazardous switching overvoltage related to switching of an opening contactor of a motor.

13 cl, 14 dwg