基于模糊多判据融合的单端暂态量保护新方案

Single Terminal Transient Protection Scheme Based on Fuzzy Multi-criteria Fusion

针对现有单端暂态量保护方案仅依赖单一故障特征进行故障识别导致可靠性不高的问题,提出了一种基于模糊多判据融合的单端暂态量保护新方案,实现不同单端暂态量保护方案间的优势互补。首先,分析了现有基于高低频暂态能量比值、故障初始零模/线模电压行波到达时间差以及前两个线模电压行波极性关系3种单端暂态量保护方案保护判据的特性及其动作灵敏区,在此基础上构造了相应判据的模糊隶属度函数;其次,针对不同暂态量保护方案的优缺点,基于模糊逻辑将上述3种单端暂态量保护方案进行有机融合以判别故障区段;最后,基于PSCAD/EMTDC的大量仿真,对比分析了上述3种暂态量保护方案以及所提新方案在不同故障位置、不同母线杂散电容、不同过渡电阻以及不同权重系数等条件下的适应性,验证了新方案的有效性。

The existing single-terminal transient protection schemes rely solely on single fault feature for fault identification,which leads to the poor identification reliability.This paper thus proposes a novel single-terminal transient protection scheme based on fuzzy multi-criteria fusion to achieve the complementation of the advantages of different single-terminal transient protection schemes through fuzzy multi-criteria fusion.Firstly,the characteristics and action sensitive regions of three single-terminal transient protection schemes,which are based on the ratio of high-and low-frequency transient energy,the arrival time difference of fault initial zeromode/line-mode voltage traveling wave and the polarity relationship of initial line mode voltage traveling wave,are analyzed,and the fuzzy membership functions of corresponding criteria are constructed.Secondly,based on the advantages and disadvantages of different transient protection schemes,the above three single-terminal transient protection schemes are integrated based on fuzzy logic to achieve fault zone discrimination.Finally,based on a large number of simulation using PSCAD/EMTDC,the three transient protection schemes mentioned above and the proposed novel scheme is compared in terms of adaptability under different fault locations,different bus stray capacitance,different transition resistance and different weight coefficients,which has verified the effectiveness of the proposed novel scheme.