Adaptive current quick-break protection method and system for superconducting current limiter access

Abstract

The invention relates to an adaptive current quick-break protection method and system for access of a superconductive current limiter, and the method comprises the steps: collecting voltage and current values of a to-be-detected circuit in real time before and after a fault; calculating the additional impedance of the to-be-detected circuit during the fault according to the voltage and current values of the to-be-detected circuit before and after the fault; calculating and obtaining a fault circuit transient voltage after the fault of the to-be-detected circuit according to the additional impedance, the set impedance of the to-be-detected circuit, the internal resistance of the superconductive current limiter and a power frequency break variable current; and transmitting a protection operation instruction to a relay when the fault circuit transient voltage is greater than or equal to the product of the voltage value of the to-be-detected circuit before the fault and the reliable coefficient of a relay. According to the invention, the method achieves a function of cutting a circuit through the relay so as to protect other devices in the circuit during the fault of the circuit after the superconductive current limiter is added to the circuit.

Description

technical field [0001] The invention relates to the field of relay protection for power systems, in particular to an adaptive current quick-break protection method and system for accessing a superconducting current limiter. Background technique [0002] In recent years, with the development of high-voltage and ultra-high voltage power grids and the expansion of the scale of power systems, the phenomenon of short-circuit current exceeding the standard has become more and more serious, which has brought great challenges to the safe and stable operation of power systems. At the same time, with the increasing maturity of superconducting technology, the superconducting fault current limiter has a simple structure, integrates detection, conversion, and current limiting functions, and has a fast impedance rise and stable impedance characteristics. It is an ideal current limiting device. It has been widely concerned by countries all over the world. [0003] The grid-hung operation ...

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide an adaptive current quick-break protection method and system for the access of a superconducting current limiter, and to solve the problem of power systems installed with fault current limiting equipment with measurable impedance such as superconducting current limiting. The problem of inadaptability of frequent variable protection; design a new fast-moving and selective adaptive current short-break protection method

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