基于变结构模型的电气设备短路电流计算

Electrical Equipment Short-circuit Current Calculation Based on Variable Structure Model

基于变结构模型短路电流计算原理,将断路器(或隔离开关)用一条支路为零的支路来模拟,从而计算出断路器两侧发生短路时,流过断路器的短路电流。该模型正好解决了电气设备的选取和校验、继电保护选择和整定中所需要解决的关键问题。给出了变结构模型的短路电流程序设计步骤,结合算例,运用C语言编制的程序给出了计算结果,并与对称分量法的短路电流计算结果进行了比较,校验该算法的实用性和正确性。

According to short-circuit current calculation principle based on variable structure model,zero impedance branch is used to simulate the circuit breaker.The short-circuit current of circuit breaker can be calculated when the short-circuit fault occurs on each side of the breaker at different time with the model.The model can be useful for the selection and verification of electric equipment as well as the critical issues to the selection and parameter tuning of relay protection.The program design steps are given in the paper.Combined with one example,the calculation obtained by the program using C language is compared with the result obtained by the method of symmetrical component to check the practicality and correctness of the algorithm.