一种含固态限流器的电力系统故障计算新方法

NEW METHOD TO CALCULATE FAULTS IN POWER SYSTEM WITH SOLID STATE FAULT CURRENT LIMITERS

采用2组相互独立、结构简单的网络组合来模拟含固态限流器的电力系统中伴有固态限流器动作的各种简单故障和复杂故障,以虚拟短路点和固态限流器两侧节点为边界,将含固态限流器的故障电力系统分解成3个无电磁联系的独立部分:模拟固态限流器动作的网络部分、对称系统部分和模拟短路故障的网络部分,将这3部分连接起来形成故障计算模型。根据线性电路的基本定理和相序参数变换技术,提出了一种计算含固态限流器的电力系统各种简单故障和复杂故障的新方法。这种方法的特点是:模拟故障和固态限流器动作所需的网络相互独立、结构简单,易于计算机自动形成其数学模型;互感支路故障与非互感支路故障处理方法完全相同,互感支路故障计算简便;可精确模拟金属性与非金属性短路故障,计算结果精确;无需修改故障前原网数学模型,计算速度快。

Based on the network theory, the simple or complex faults in power system with solid state fault current limiters are modeled as the combination of two simple independent networks. By taking fictitious fault points and the terminal ports of solid state fault current limiters as boundary terminal ports, the faulted power system with solid state fault current limiters is divided into the three independent parts, that is, a network to simulate the operations of solid state fault current limiters, a symmetrical system and a network to simulate faults. On this basis, a model for calculating the faults in power systems with solid state fault current limiters is developed. According to the basic theory of linear circuit and the phase-sequence parameter transformation technique, a new method to calculate the simple or complex faults in power systems with solid state fault current limiters is presented, which has the following characteristics: ①the networks used to simulate faults and operations of solid state fault current limiters are very brief and independent, so it is easy to constitute their mathematical model; ②the method used to calculate faults on the lines with or without zero-sequence mutual couplings is same, and therefore the calculation of the faults on zero-sequence mutual coupled lines becomes very simple; ③the simple or complex faults can be modeled accurately, including metallic short circuit faults, so the calculation results of the method are precise; ④the faults are calculated without modifying the Zbus or Ybus of each original networks, and therefore the method is effective.