变结构模型发电厂主系统短路电流计算方法

提出将断路器作为一条阻抗为零的支路模拟，应用线性网络特性、定理及变结构与变参数方法．导出了相当于在断路器两侧分别发生短路故障时，计算通过断路器短路电流的通用模型和算法。用该计算模型对某电厂进行短路电流计算，计算表明其结果的正确性。该方法适用于电气设备选择和继电保护整定计算，同时，还能考虑各种运行方式的改变对短路电流的影响。

Calculation method of short-circuit current for power plant master system with variable structure model

It is proposed to simulate the circuit breaker with a zero impedance branch. Based onlinear network characteristics and theorem,and with variable structure and variable parameter method,the universal model and algorithm for calculating the short-circuit current of circuit breaker is derived as short-circuit fault happens on each side of it at different time. The model is used in short-circuit current calculation for a power plant and the calculative results are right. The method is suitable for electrical equipment selection and setting calculation of relay protection. It can also be used to valuate the influence of operation mode change on short-circuit current.