Mechanical type high-voltage DC breaker on-off equivalent test loop and method

Abstract

The invention discloses a mechanical type high-voltage DC breaker on-off equivalent test loop and method. The on-off equivalent test loop comprises a current source, an auxiliary loop, a frequency modulation loop and a voltage source, wherein one end of the auxiliary loop is connected with the current source, the other end of the auxiliary loop is connected with a mechanical switch in a mechanical type high-voltage DC breaker, the frequency modulation loop is connected in parallel with the mechanical switch, and the voltage source is connected in parallel with the frequency modulation loop. According to the invention, due to addition of a parallel capacitor C, the equivalent capacitance value of a conversion loop after current zero-crossing of the mechanical switch is greatly reduced. Since the voltage source oscillates with the conversion loop in the mechanical type high-voltage DC breaker and the frequency modulation loop through the parallel capacitor C in the auxiliary loop after current zero-crossing arc blowout of the mechanical switch, the oscillation frequency can be improved by reducing the equivalent capacitance value of the conversion loop, and the rate of rise of recovery voltages can be effectively improved.

Description

technical field [0001] The invention belongs to the field of testing of mechanical high-voltage direct current circuit breakers, and more specifically relates to a breaking equivalent test circuit and method of mechanical high-voltage direct current circuit breakers. Background technique [0002] In recent years, with the development of flexible DC transmission technology and the advancement of high-power power electronics technology, HVDC transmission has been valued and developed due to its unique advantages. The development of high-voltage DC circuit breakers has become the main bottleneck in the establishment and development of multi-terminal DC power grids. Therefore, more and more attention has been paid to the research of high-voltage DC circuit breakers at home and abroad in recent years. [0003] According to the different key switching devices of high-voltage DC circuit breakers, they can be divided into three categories: mechanical DC circuit breakers, all-solid-s...

AI Technical Summary

Problems solved by technology

Due to the principle characteristics of the mechanical DC circuit breaker, which adopts the principle of manual zero crossing, the parameters of the commutation circuit have a great influence on the test results of the mechanical DC circuit breaker

When the traditional AC synthesis circuit is used to test the DC circuit breaker, there is a problem that the actual current breaking process voltage cannot be equivalent, that is, the recovery voltage rise rate after the current zero crosses cannot reach the recovery voltage rise rate during the actual DC breaking process Because the large capacitance of the commutation circuit limits the rapid rise of the recovery voltage, the equivalent of the DC circuit breaker test using the traditional synthetic circuit test method is insufficient

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