摘要
主设备保护通常采用差动原理作为主保护原理,随着数字保护在电力系统的广泛应用,存在电流互感器(TA)暂态饱和易引起差动保护误动的问题。数字差动保护抗TA饱和的线性区方案是建立在TA暂态饱和时一次电流每个周期过零时始终存在一定的线性传变区域的理论基础上,对TA传变的数据取最小的线性区选择方法,动作电流采用半波傅里叶滤波算法计算,制动电流采用全波傅里叶滤波算法计算,构成比率制动差动保护。该方案原理简单、实现方便,动模录波数据说明该方案能够基本消除区外故障TA暂态饱和引起差动保护误动的情况,可直接应用于变压器差动保护、发变组差动保护和母线差动保护,应用前景良好。
At present, current differential protection is widely applied to electrical equipment main protection. With the wide use of digital protection in power systems, it has been found that current transformer transient saturation can easily result in protection mal-operation. Linear strategy of current transformer anti-saturation for digital differential protection is based on the fact that linear data always exist per cycle during current transformer transient saturation. This specific strategy is to make full use of linear data to prevent ratio restraint differential protection from mal-operating during external faults. Exactly operating current phasor is calculated by half-cycle Fourier algorithm and the only minimum one is selected while restraining current phasor is calculated by full-cycle Fourier algorithm. Dynamic simulation data indicate that the strategy will eliminate the maloperation caused by current transformer transient saturation during external faults. Finally the prospective application of transformer, generator-transformer and busbar differential protection with linear strategy of current transformer anti-saturation principle is described.
出处
《电力系统自动化》
EI
CSCD
北大核心
2007年第4期66-70,107,共6页
Automation of Electric Power Systems
关键词
差动保护
电流互感器饱和
线性区
电流互感器
differential protection
current transformer saturation
linear data
current transformer
