Resonant filter-based MMC DC deicing device and design method thereof

Abstract

The invention belongs to the technical field of electric power system control, and in particular relates to a full-bridge type MMC DC deicing device based on a resonant filter and a design method thereof. The device includes sequentially connected circuit breakers, isolating switches, connecting reactors, full-bridge MMCs based on resonant filters, four ice-melting knife gates, and AC lines to be ice-melted. The method includes: determining the line coverage of the DC ice-melting device; calculating the ice-melting current of each conductor within the covered line range; calculating the DC voltage and DC power according to the ice-melting current and the ice-melting wiring mode; calculating the full-bridge type MMC DC ice-melting device The number of sub-modules; calculating the capacitance value of the sub-module capacitor of the full-bridge MMC DC deicing device; calculating the reactance value of the bridge arm reactor of the full-bridge MMC DC deicing device; calculating the parameters of the resonant filter.

Description

technical field [0001] The invention belongs to the technical field of electric power system control, and in particular relates to a full-bridge type MMC DC deicing device based on a resonant filter and a design method thereof. Background technique [0002] Among the natural disasters encountered by various power systems, ice and snow disasters are one of the most serious. Compared with other accidents, the losses caused by ice and snow disasters to the power grid are generally more serious, ranging from ice flashes to downed towers and broken lines, and even power network paralysis. [0003] At present, in order to improve the power grid's ability to resist ice and snow disasters, there are many methods and equipment for deicing and melting lines. The ice melting methods proposed at home and abroad are generally divided into four categories: thermal ice melting, mechanical deicing, natural passive deicing and other methods. Mechanical deicing is not easy to operate, and t...

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Problems solved by technology

[0004] The traditional DC deicing device can achieve reactive power compensation and DC deicing mode conversion through the simple opening and closing operation of the external isolating switch, but the harmonics generated during operation are relatively large, and the response speed is slightly slow, so a large-capacity filter needs to be installed When the traditional DC ice melting device SVC is running, the voltage stress and valve loss are relatively large, and the DC ice melting and reactive power compensation device operates in the reactive power compensation mode most of the time, resulting in a greatly reduced comprehensive operating benefit

These characteristics greatly limit the application range of traditional direct current ice melting devices

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