Recognition method of open-circuit fault of high-voltage capacitor of double-tuning AC filter

Abstract

The invention discloses a recognition method of an open-circuit fault of a high-voltage capacitor of a double-tuning AC filter. The method includes main steps: acquiring an unbalanced current on an unbalanced bridge and a to-ground voltage of the unbalanced bridge in the high-voltage capacitor of the double-tuning AC filter, and calculating an unbalanced reactive power; indicating that the high-voltage capacitor has the open-circuit fault if the unbalanced reactive power is greater than a threshold; and indicating that the high-voltage capacitor does not have the open-circuit fault if the unbalanced reactive power is less than the threshold. According to the method, the unbalanced reactive power is regarded as a recognition criterion, the open-circuit fault of the high-voltage capacitor isrecognized, the recognition is accurate and reliable, reliable protection can be provided for the high-voltage capacitor of the AC filter, the method is free of the influence of the system operationmode and the voltage level change etc., and the system is applicable to all high-voltage DC power transmission systems adopting the double-tuning AC filter.

Description

technical field

[0001] The invention relates to a high-voltage capacitor disconnection fault identification method used in a double-tuned AC filter in a high-voltage direct current transmission system. Background technique

[0002] At present, HVDC transmission technology has been widely used in my country's transmission projects because of its advantages of long-distance and large-capacity transmission. During HVDC power transmission, it is necessary to convert AC to DC at the front end of transmission, and convert DC to AC at the back end of transmission. The conversion device of AC and DC is called a converter device. During the operation of the converter device, it will generate harmonics on its AC side and consume reactive power of the system. Therefore, an AC filter is installed on the AC side of the converter device to filter out harmonics and provide reactive power to the system. The double-tuned AC filter is widely used in high-voltage DC transmission projects bec...

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