Solid-state fault current limiter

Abstract

The present invention provides a solid-state fault current limiter, including current-limiting reactance L1, current-limiting reactance L2, current-limiting reactance L3, thyristor valve T1, thyristor valve T2 and bypass circuit breaker K; current-limiting reactance L1 and current-limiting reactance L2 The thyristor valve T1 and the thyristor valve T2 are connected in series to form a thyristor valve branch. Both the bypass circuit breaker K and the thyristor valve branch are connected in parallel with the current-limiting reactance branch. One end of the current-limiting reactance L3 is connected to the limiting The midpoint of the current-limiting reactance L1 and the current-limiting reactance L2 is connected with the midpoint of the thyristor valve T1 and the thyristor valve T2 at the other end. The technical solution provided by the invention can realize almost no influence on the power system during normal operation, and automatically limit the short-circuit current after a fault occurs. Moreover, the solid-state fault current limiter provided by the present invention has low requirements for fault identification speed, simple structure, no fully-controlled power electronic devices, and the current limiting effect on the peak value of the short-circuit current and the steady-state value can be adjusted respectively by changing the current-limiting reactance , which is convenient for engineering application.

Description

technical field [0001] The invention relates to the technical fields of power systems and power electronics, in particular to a solid-state fault current limiter. Background technique [0002] The scale of the power system is getting larger and larger, and the problem of excessive short-circuit current levels is becoming more and more serious. The traditional methods of limiting short-circuit current, such as changing the structure of the power system and installing series reactance, etc., will have adverse effects on the normal operation of the power system. The fault current limiter (fault current limiter, FCL) can achieve no impact on the power system during normal operation, and quickly increase the impedance after a short-circuit fault occurs, which is an effective way to limit the short-circuit current. At present, fault current limiters mainly include superconducting type, saturated iron core type, transformer type, etc., but all of them have problems in terms of tec...

AI Technical Summary

Problems solved by technology

The current solid-state fault current limiters mainly include parallel switch type, bridge type and series resonant type, but these solutions are insufficient or lacking in terms of technical difficulty, cost and land occupation. It is necessary to study a new type of solid-state fault current limiter device

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