STATION FOR CONTROL OF ASYNCHRONOUS MOTORS (EMBODIMENTS)

摘要

A control station for asynchronous motors comprises a voltage rectifier, a capacitive filter connected in parallel to the said rectifier, sensors of rectifier input currents, an overvoltage limiter and a control device for three-phase circuit voltage connected in parallel to rectifier input, an invertor having diodes and keys with control inputs, invertor input is connected to the capacitive filter, invertor output – to windings of at least one motor, a sencor for invertor input voltage, sensors of invertor output currents, a control unit performed as a microprocessor controller provided with an indication device and a power supply unit, and contains signal shapers, control inputs of invertor’s keys are connected to output of the said shapers, an insulation resistance control unit, one input thereof is connected to DC voltage circuits between the capacitive filter and the invertor, second input – to AC voltage circuits of invertor output, output of the insulation resistance control unit is connected to the control unit. The control station comprises a main (network) contactor with input connected to the supply network; control input of the main contactor is connected to output of the control unit which is connected to the sencor of invertor input voltage. In one embodiment, a station having an uncontrolled rectifier, between thereof and the network contactor, an inductive filter may be connected. The control station also comprises a reducing transformer, the primary winding of which is connected to the supply network. To secondary winding of the reducing transformer, a power unit of the control unit is connected via a contact of an overvoltage protection device; and voltage multiplier input is connected via a relay, output of which is connected to the capacitive filter. Moreover, the station is provided with a protection device, control inputs of which are connected to control inputs of invertor keys, as well as to input of the network contactor in parallel to the control unit. The protection device is connected to the voltage supply control device and sensors of input currents output, sensors of invertor output currents are connected to the protection device in parallel to the control unit. In another embodiment, a station having a controlled rectifier, the station comprises a rectifier control unit with an inductive filter, which is in parallel connected to the rectifier. The rectifier control unit comprises a three-phase resistive bridge, outputs of which are connected to microprocessor controller via electrical isolation devices, control input of the said controller are connected to control inputs of rectifier’s keys.