Ultrahigh-voltage and extra-high-voltage multi-break quick vacuum circuit breaker topological structure

Abstract

The invention discloses an ultrahigh-voltage and extra-high-voltage multi-break quick vacuum circuit breaker topological structure, which is characterized in that the multi-break quick vacuum circuit breaker adopts a series-parallel topological connection structure and is formed by connecting a plurality of same branches in parallel, and the number of the parallel branches and the number of series fractures of each branch are determined according to design parameters; the number of the parallel branches is determined according to the rated through-current capability of the circuit breaker, each parallel branch is formed by connecting a plurality of same circuit breaker units in series, the number of series fractures refers to the requirements of power frequency withstand voltage and lightning impulse withstand voltage of the circuit breaker, one redundancy is added on the basis that the number of fractures meets the insulation requirement, and a vacuum circuit breaker operating mechanism adopts a rapid repulsion mechanism. The topological structure is applied to development and design of ultrahigh-voltage and extra-high-voltage rapid vacuum circuit breakers, the problem that balance and current sharing of all parallel units are difficult to achieve in a traditional topological structure of the circuit breaker is solved, it is only needed to guarantee that the total contact resistance of all parallel branches is equal, and the requirement for model selection of the vacuum arc-extinguishing chamber is lowered.

Description

technical field [0001] The invention relates to the field of rapid vacuum circuit breakers, in particular to a method for determining the topological structure and the number of fractures of ultra-high voltage and ultra-high voltage multi-fracture rapid vacuum circuit breakers. Background technique [0002] In recent years, with the continuous expansion of the grid scale and the continuous increase of the voltage level, the power load has increased sharply, and the phenomenon of short-circuit current exceeding the standard frequently occurs. At present, there is no means to reliably cut off the excessive short-circuit current under the EHV / UHV voltage level. Fast vacuum circuit breakers have the advantages of short opening time and low dispersion, and the positive volt-ampere characteristics of vacuum arcs make it possible to design EHV / UHV multi-break fast vacuum circuit breakers in a series-parallel combination. [0003] The patent "363kV circuit breaker based on fast rep...

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Problems solved by technology

[0003] The patent "363kV circuit breaker based on fast repulsion switch" (201710692842.1) proposes a topology structure of circuit breakers in parallel first and then in series, which solves the problems of long breaking time and excessive inrush current of traditional circuit breakers, and is realized in the first Reliable breaking of short-circuit current within half-wave (10ms)

However, due to the structure of parallel first and then series, once a certain fracture fails, all the current will flow through the parallel fracture, which greatly increases the failure probability of the parallel fracture and leads to the failure of the entire circuit breaker.

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