Single-phase heavy-current compound switch and control method thereof

Abstract

Provided in the invention is a single-phase heavy-current compound switch comprising a housing, a socket and a circuit structure. The circuit structure consists of a control signal access terminal, an input control module, a power supply module, a power supply access terminal, an NE555 monostable control module, a zero-crossing output control module, a thyristor module, a capacitor connection terminal, a relay control module, a magnetic latching relay and a main loop access terminal. According to the the single-phase heavy-current compound switch, the thyristor is connected to a circuit in a zero voltage state and the response time is less than 20ms; and the circuit is disconnected in a zero current mode. No impulse and surge currents occur during the connection and disconnection processes and the response speed is fast. The bearing is carried out by switching to a contact of an alternating-current contactor within 50ms of thyristor conduction; no voltage drop and no loss are cause; no heat radiator is needed to be installed; and the service life of the compound switch is prolonged. The single-phase heavy-current compound switch with the dustproof sealed iron housing design is suitable for dynamic switching of a heavy-current single-phase compensation capacitor in a dusty environment.

Description

technical field [0001] The invention relates to the technical field of reactive power compensation, in particular to a single-phase high-current composite switch and a control method thereof. Background technique [0002] Install reactive power sources in substations in the power system or directly in power user substations to change the flow of reactive power in the power system, thereby increasing the voltage level of the power system, reducing network losses and improving the power system Dynamic performance, this technical measure is called reactive power compensation. [0003] In the implementation process of power grid transformation, it is often necessary to add a shunt capacitor reactive power compensation device, which plays a positive role in improving the quality of power supply voltage, tapping the potential of power supply equipment, reducing line loss and saving energy. [0004] Most of the early reactive power compensation devices used switching methods such ...

AI Technical Summary

Problems solved by technology

[0004] Most of the early reactive power compensation devices used switching methods such as AC contactors and thyristor electronic switches. AC contactors will generate large inrush currents and overvoltages when capacitors are switched on and off, and transient high voltages and switching impulse currents It will lead to insulation breakdown of capacitors and burnout of contacts of contactors. Although the thyristor electronic switch solves the problems of inrush current and overvoltage breaking arc during the switching process of capacitors, it is difficult to dissipate heat, and many auxiliary heat dissipation devices are needed. The structure is complex, the cost is high, and it takes up a lot of space. The compensation effect and service life of the two methods are not ideal.

Images