Thyristor-based solid state fault current limiter

Abstract

The invention provides a thyristor-based solid state fault current limiter. The solid state fault current limiter comprises three single-phase current limiters; each single-phase current limiter comprises a main circuit and a breaker; the main circuit comprises a first current-limiting reactor and a second current-limiting reactor that are in series connection, and a first thyristor and a second thyristor; the solid state fault current limiter is serially connected to a power transmission line; when the circuit has no faults, the current limiter works normally, the thyristor is switched on constantly, and the equivalent impedance of the current limiter is basically 0; when the circuit has faults, the current limiter enters a current-limiting working state automatically without delay to limit a first peak value of the short circuit current; then the two current-limiting reactors are fully connected to the circuit by removing the trigger signal of the thyristor to limit a steady-state value of the short circuit current. The thyristor-based solid state fault current limiter has low demand on the fault identification speed without requiring to add a bypass current-limiting reactor, so that the thyristor-based solid state fault current limiter is simple in structure, high in reliability, and convenient in engineering applications.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a thyristor-based solid-state fault current limiter. Background technique [0002] The rapid development of the power system has led to a new prominent problem, namely, the increasing level of short-circuit current in the power grid at all levels. The short-circuit current in some areas of the system has reached or even exceeded the interrupting capacity of the circuit breaker, which seriously threatens the safe operation of the system. Although traditional current limiting technologies such as increasing the voltage level and adopting series reactance can suppress the short-circuit current of the system to a certain extent, they will all have a negative impact on the normal operation of the system. Using a fault current limiter (Fault Current Limiter, FCL) has become a new way to solve the problem of excessive short-circuit current. It is characterized in that it pres...

AI Technical Summary

Problems solved by technology

This solution has low loss and has been applied in demonstration projects, but the protection and bypass equipment are complicated, occupying a lot of space and cost

[0010] The above-mentioned solutions are insufficient or lacking in terms of technical difficulty, cost, and land occupation. Therefore, it is necessary to provide a new type of solid-state fault current limiter that has no impact on the power system during normal operation and automatically limits the short-circuit current after a fault occurs.

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