Current-limiting self-charging type artificial zero-crossing high-voltage DC circuit breaker and disconnecting method thereof

Abstract

The present invention discloses a current-limiting self-charging type artificial zero-crossing high-voltage DC circuit breaker and a disconnecting method thereof. The circuit breaker comprises a current-limiting module, a DC disconnecting module and a charging module, the current-limiting module is realized by a superconducting current-limiting unit, the DC disconnecting module comprises a currentcommutation capacitor, a discharging change-over switch, a current commutation inductance coil and a mechanical switch, and the charging module is realized by a charging change-over switch. The coresof the present invention are that when a short circuit fault occurs, the superconducting current-limiting unit limits the increase of a short circuit current, at the same time, by the parallel connection of the superconducting current-limiting unit and the current commutation capacitor, a withstanding voltage during a superconducting quench process is utilized to realize the self-charging of thecurrent commutation capacitor, thereby eliminating the adverse influence of the charging equipment reliability on the disconnection reliability. According to the present invention, the cost of the pre-charging equipment can be saved, the disconnection capacity and the working reliability of the disconnecting equipment are improved.

Description

technical field [0001] The invention relates to a power system circuit breaker, in particular to a current-limiting self-charging artificial zero-crossing high-voltage direct current circuit breaker and a breaking method thereof. Background technique [0002] Flexible DC transmission technology is an effective way to build a flexible, strong and efficient power grid and make full use of renewable energy, representing the future development direction of DC transmission. When a short-circuit fault occurs on the DC side of the flexible DC grid, the impedance of the DC side is small, and the capacitor on the DC side of the converter is directly discharged through the short-circuit point. Scale AC grid. At the same time, when a fault occurs on the DC side of the system, even if the insulated gate bipolar transistor (IGBT) inside the converter is immediately shut off through the self-protection function, due to the existence of the freewheeling diode, an uncontrolled rectificatio...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the deficiencies of the existing methods, the present invention provides a current-limiting self-charging artificial zero-crossing high-voltage DC circuit breaker and its breaking method. The terminal voltage generated during current limiting charges the commutation capacitor, which aims to solve the technical problems of insufficient breaking capacity and reliability of the pre-charging device in the prior art

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