THYRISTOR DEVICE FOR SMOOTH START OF HV SYNCHRONOUS ELECTRIC MOTOR BY UNDERFREQUENCY RELAY (VERSIONS) Russian patent published in 2012 - IPC H02P1/52 

FIELD: electricity.

SUBSTANCE: according to the first version, the thyristor device for smooth start of a HV synchronous electric motor by the underfrequency relay contains a dependent frequency converter consisting of a thyristor rectifier, a thyristor inverter, a smoothing choke, a transistor inverter, a transistor inverter with a control unit and a filter capacitor at the outputs, a voltage stabiliser paralleled to the filter capacitor, commutation apparatus connecting the corresponding input and output clamps of the thyristor and the transistor inverter by means of power contacts. According to the second version, the device contains all the elements as per the first version and, additionally, a unit setting the intensity of connection with the transistor inverter control unit and the voltage controller.

EFFECT: decrease of weight, overall dimensions and cost of the device for smooth start of HV synchronous electric motors at reduced pulsations of the electric motor torque in the low-speed area.

8 cl, 3 dwg