A solid-state composite switching device and a control method thereof

Abstract

A solid-state composite switching device comprises a mechanical switch QF, a thyristor valve group, an arc suppression transformer and an arc suppression power supply; The mechanical switch QF is connected in series with the high-voltage side of the arc suppression transformer and then connected in parallel with the thyristor valve group; A low-voltage side of that arc suppression transform is connected in parallel with the arc suppression pow supply; The thyristor valve group is connected with the valve-based electronic equipment; The thyristor valve group, the mechanical switch QF and the arc suppression power supply operate according to the opening and closing commands issued by the valve-based electronic equipment respectively; The composite switching device provided by the invention is suitable for medium-voltage distribution power system, has no arc and overvoltage under any working state, and has small energy loss, meets the needs of frequent operation of switches in medium-voltage distribution power system, and prolongs the service life of mechanical switches, which has very important significance in industrial production.

Description

technical field [0001] The invention relates to a switch device of a medium-voltage power distribution system, in particular to a solid-state composite switch device and a control method thereof. Background technique [0002] With the development of social economy, the breadth and depth of electrification of social production are increasing day by day, the form of electricity consumption is diversified, and the demand for electricity quality is becoming increasingly stringent. In large industrial production industries, such as: metallurgy, electrified railway, oil exploration, chemical production, etc., in order to meet the requirements of high-power electricity consumption, the medium-voltage distribution network with voltage levels of 10kV, 27.5kV, and 35kV is often directly used for power supply. Therefore, frequent operation of circuit breakers in the medium voltage distribution network is unavoidable under certain operating conditions. However, in the working condition...

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Problems solved by technology

However, when the composite switch is in the on state, the series reactor is always connected to the loop. On the one hand, there will be power loss when the reactor continues to work. On the other hand, the voltage drop caused by the series reactor will also have a certain impact on the load.

Furthermore, when the composite switch is turned off, the electromagnetic energy stored in the series reactor needs to be released in the circuit, which manifests itself as overvoltage between the reactor terminals, and the overvoltage caused by frequent shutdown operations will cause damage to the mechanical switch and the thyristor valve group. damage

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