A resistance sensing type capacitor commutation hybrid current limiter and a control method thereof

Abstract

The invention provides a resistance sensing type capacitor commutation hybrid current limiter and a control method thereof. The hybrid current limiter includes an on-state low-loss branch, a current-transfer branch and a current-limiting branch. The hybrid current limiter adopts a half-controlled device, is simple in logic, and is economical and reliable. The current limiter has low steady-state loss and has bidirectional current limiting capability, which can effectively suppress the short-circuit current of a DC grid and reduce the dissipated energy of a lighting arrester. The current limiter greatly delays the blocking time of a sub-module IGBT, and obtains sufficient time for the remaining protection devices. The use of half-controlled power electronic device can save the parallel number of power electronic devices and save costs, and ensure that a current limiting resistor and corresponding heat sinks are fully utilized to improve the current limiting effect. The control method ofthe resistance sensing type capacitor commutation hybrid current limiter provided by the invention realizes the control of the resistance sensing type capacitor commutation hybrid current limiter ina condition when a DC line where the current limiter is located operates normally or in a condition before or after the DC line where the resistance sensing type capacitor commutation hybrid current limiter is located is disconnected.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a resistance-inductance capacitive commutation hybrid current limiter and a control method thereof. Background technique [0002] High-voltage and large-capacity DC grid technology is an important link in the future construction of smart grids and global energy Internet. Flexible DC transmission technology based on modular multilevel converter (MMC) facilitates the construction of DC power grids, thus becoming a new expectation in the power industry. my country's upcoming Zhangbei DC power grid adopts the half bridge sub module plus overhead line scheme, which is the world's first DC power grid engineering practice. The use of overhead lines has obvious technical and economic advantages, but the ensuing problem is the high probability of faults on the DC side. Combined with the fact that the half-bridge sub-module does not have the ability to clear faults on the DC sid...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the problems of high loss and poor economy of the solid-state DC current limiter in the above-mentioned prior art, as well as the high manufacturing cost and large equipment volume of the superconducting current limiter, the present invention provides a hybrid current limiter of resistive-inductive capacitive commutation and its control method, the resistive-inductive capacitive commutation hybrid current limiter includes an on-state low-loss branch, a current transfer branch and a current-limiting branch

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