特高压中州换流站保护三取二逻辑优化分析

Optimization Analysis for Two-out-of-Three Logic of DC Protection in UHV Zhongzhou Converter Station

保护三取二逻辑具有较低的误动率和拒动率,在换流站的保护系统中广泛应用。由于所保护的设备不同,三取二逻辑的实现方法也有所区别,以中州换流站内的直流系统保护、换流变非电量保护为研究对象,从三取二逻辑的模拟量采集回路、开关量采集回路以及出口回路入手,同时结合以往工程中保护三取二逻辑的实现方式,对中州换流站保护的三取二逻辑进行了全面的分析,找出了其中存在的问题,并提出相关改进意见,为后续工程的设计提供一些依据。

Two-out-of-three （2 of 3） logic is widely used in DC protection system of converter stations, because of its lower malfunction and rejection rate. There are different methods to implement two-out-of-three logic, according to different devices. Taking the DC system protection of Zhongzhou converter station and the non-electrical protection of converter transformer as research objects, this paper comprehensively analyzed the two-out-of-three logic of DC protection in Zhongzhou converter station, including analog value acquisition circuit, digital value acquisition circuit and trip circuit, combined with the realization way of two-out-of-three logic of DC protection in previous projects. Finally, the problems were found, and some improvement suggestions were proposed, which could provide some basis for the design of follow-up projects.