Method for stopping series-side converters of multiple circuits of unified power flow controller

Abstract

The invention relates to a method for stopping series-side converters of multiple circuits of a unified power flow controller. The method comprises the steps of 1) decreasing output voltage of a series-side transformer of the series-side converter of any circuit to 0, and latching and controlling power flow of the current circuit; 2) carrying out an operation on the other circuits sequentially according to the step 1); 3) when the series-side converters of each circuit are latched and controlled at the power flow of the current circuit, sequentially closing bypass switches at primary sides of the series-side transformers; 4) sequentially transferring the power flow of each circuit to the bypass witch thereof after the bypass switches are closed; and 5) latching the series-side converter of each circuit so as to accomplish the series-side converter stopping process of the multiple circuits. According to the method provided by the invention, the power flow is stably lifted to the natural power flow before the converters are withdrawn, thereby effectively suppressing current surge when the bypass switches are closed, reducing power flow oscillation of an alternating current circuit, and realizing stable stopping of a double-circuit unified power flow controller.

Description

technical field [0001] The invention relates to the fields of power electronics and AC power transmission, in particular to a method for stopping operation of a converter on a series side of a multi-circuit line of a unified power flow controller. Background technique [0002] With the rapid development of the power system, its operational flexibility, controllability and stability have become more and more urgent problems to be solved; large-scale distributed energy sources such as solar energy and wind power are connected to the power system, which further increases the security of the system. The complexity of power flow regulation. In addition, there are many long-distance transmission lines in my country, and the power grid structure is relatively weak. It can improve the power transmission capacity of existing lines and maximize the transmission capacity of the power grid; improve the transient stability of the power system and damp system oscillation; optimize the pow...

AI Technical Summary

Problems solved by technology

[0005] The invention provides a method for outage of the converters on the series side of the multi-circuit line of the unified power flow controller to solve the problem of coordinated outage of the converters on the series side of the unified power flow controller lacking double-circuit or multi-circuit lines in the prior art. shipping method problem

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