摘要
传统的电容电流相量补偿方法不能补偿暂态电容电流,难以满足超高压长线电流差动保护的要求。该文提出了输电线路Π模型的电容电流的时域补偿方法,利用微分方程模型对瞬时值进行补偿计算,能够有效补偿暂态和稳态电容电流。通过对该时域补偿方法和贝瑞隆线路模型法的具体分析和ATP仿真比较表明,贝瑞隆线模法在理论上能够完全补偿电容电流,但其要求采样频率高,计算量大,现有保护装置的采样速率和通道传输速率尚不能满足其要求;基于Π模型时域补偿法的差动保护适合应用短数据窗的小矢量算法,保护动作速度可提高到5ms,保护的灵敏度和选择性均有明显的提高,而且计算量小,不需要提高采样频率,不增加通信量,适合应用于现有保护装置中。
The transient capacitive current cannot be compensated by conventional phasor compensation method, thus making it difficult to satisfy the requirements of current differential protection of UHV transmission lines. This paper presents a novel time-domain capacitive current compensating algorithm based on 11 equivalent circuit. Evaluating on the instantaneous values of differential equation model, the proposed algorithm enables effective compensation of both transient and steady-state distributed capacitive current. Analysis and ATP simulating comparison have been carried out between the proposed algorithm and Bergeron model method. Though Bergeron model can be used to completely, in principle compensated capacitive current, it requires heavy computation and high sampling rate, which are beyond the communication rate and sampling frequency existing relay devices can offer. On the other hand, the relay built based on the proposed algorithm can operate under lower sampling frequency without increasing computation and the telecommunication traffic. This method fits in with phaselet algorithm, thus is able to enhance the relay speed substantially. Simulations show that while the algorithm has reduced the actuating time of differential protection to 5ms, selectivity and sensitivity of differential protection have been improved.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2006年第5期12-18,共7页
Proceedings of the CSEE
基金
国家"十一.五"重点科技攻关项目(ZZ03-07-01-05-03)。~~
关键词
电力系统
差动保护
电容电流补偿
超高压长线
Power system
Differential protection
Capacitive current compensation
UHV transmission line
