A Comprehensive Discrimination Method for Dead Zone Faults in a Substation with Semi-Main Connections

Abstract

The invention discloses a comprehensive judgment method for a semi-main wiring transformer substation dead zone fault. The method comprises the steps that the three-phase current of each breaker of a whole transformer substation and three-phase voltage on each string are collected in real time; each bus protection, line protection and transformation protection tripping signal in the whole transformer substation is sampled; the three-phase current of the breakers, the three-phase voltage and zero sequence voltage on each string and interphase impedance of the breakers are calculated, a fault area is selected according to the sampled protection tripping signals, and comprehensive fault locating is carried out through the breaker current magnitude and waveform characteristics obtained after protection tripping and the voltage and impedance magnitude. According to the comprehensive judgment method utilizing full substation information of the transformer substation, a breaker unit suffering from the dead zone fault of the transformer substation is selected, high safety is achieved, the acting speed is high, the result can be applied to station domain breaker dead zone protection judgment, the fault clearing time of breaker dead zone protection can be greatly shortened, and the safety of a large power grid electric system is improved.

Description

technical field [0001] The invention belongs to the field of relay protection for power systems, and specifically relates to dividing fault areas based on tripping signals of existing protections (bus protection, line protection, and transformer protection) on site, and utilizing the current characteristics, voltage characteristics and impedance of circuit breakers associated with the fault areas A fault discrimination method for circuit breaker dead zone based on comprehensive discrimination based on features. Background technique [0002] The reverse distribution characteristics of primary energy and power load in my country make the development of long-distance and large-capacity ultra-high voltage AC-DC transmission technology a basic national condition. my country has initially implemented a large-scale interconnected power grid with transactional and DC mutual coupling. As the power structure transitions to a combination of conventional energy and new energy such as wi...

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Problems solved by technology

For example, if the AC short-circuit fault of the East China Power Grid cannot be removed quickly, it may cause continuous commutation failure of seven DC circuits at the same time, and the resulting transient energy impact can reach up to 32 million kilowatts. Cause huge impact, lead to instability of transient power angle between generator groups, and there is a risk of grid stability damage

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