High-reliability unified power flow controller suitable for double-circuit line

Abstract

The invention provides a high-reliability unified power flow controller suitable for a double-circuit line. The high-reliability unified power flow controller comprises at least one parallel transformer, four converters, at least two series transformers, a parallel-side back brake loop, a series-side back brake loop and a direct-current public bus. At least one side of each series transformer is connected with at least one set of bypass switches in parallel. The alternating current side of at least one converter is connected with at least one series transformer through the series-side back brake loop to be connected into the line in series. The alternating current side of at least one converter is connected with the at least one parallel transformer through the parallel-side back brake loop to be connected into an alternating current system. The direct current sides of the converters are connected to the direct-current public bus through change-over switches. By means of the structure, multiple operation modes can be achieved, and when one converter breaks down, power flow of the double-circuit electric transmission line and the voltage of the parallel-side alternating current system can still be controlled; when two converters break down, control over the power flow of the double-circuit line can be achieved, and the good flexibility and the good reliability are achieved.

Description

technical field [0001] The invention relates to a flexible AC power transmission technology, in particular to a high-reliability unified power flow controller suitable for double-circuit lines. Background technique [0002] With the interconnection of large-scale power systems and the use of various new equipment, the scale and complexity of the power system have also increased while making power generation and transmission more economical and efficient; coupled with a large number of distributed power generation systems connected to the grid , so that the traditional fixed power flow transmitted from the transmission network to the distribution network is reversed; the continuous growth of user load requires power flow control means to improve the existing power transmission capacity; the complex power exchange between the booming smart grid and the power market requires Frequent flow control. [0003] The unified power flow controller, also known as UPFC (Unified Power Fl...

AI Technical Summary

Problems solved by technology

If a set of UPFC is installed in each circuit of the double-circuit line according to the UPFC structure of a single line, after any converter fails, the power flow control of the double-circuit transmission line cannot be realized, and only by disconnecting one line, the single-circuit line Running with UPFC, performing power flow control, or withdrawing the entire set of UPFC, and running double-circuit lines without UPFC, these two methods will reduce the power transmission capacity and reliability of the grid

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