一种云广特高压换流变保护配置无冗余问题改进方法

摘要

In Yun-Guang HVDC system, the converter transformer protection is not redundant, the reason is that the CT configuration of converter transformer bushing is not enough. This paper proposes an improved method to solve the problem of non-redundancy of converter transformer protection. Considering the structural features of converter transformer, i.e Y/Y wiring and Y/△wiring parallel connection, this mothod changes CT secondary wiring connection of converter transformer bushing, cooperates it with CT of converter transformer feeder breaker, and modifies the corresponding protection criterion. Thus the protection dual configuration problem caused by insufficient configurations of converter transformer bushing CT and neutral point CT is improved. The protection device before/after improving is tested on RTDS, the results show that the improved protection performance is increased to some extent and can basically solve the non-redundant problem.%以云广特高压直流输电系统为背景，为解决换流变保护因 CT配置不够导致的配置不冗余问题，提出了一种换流变保护的改进方法。该方法针对换流变Y/Y接、Y/△接并联接线的结构特点，通过改进换流变套管CT二次接线，与换流变馈线开关CT进行配合，并修改相应保护判据，调整保护原理配置，改善了因换流变网侧套管CT以及中性点CT配置不足而产生的保护双重化问题。对改进前后的保护装置进行了 RTDS试验验证，结果表明改进后的换流变保护性能有所提高，基本实现了两套保护装置的冗余配置。