投切负载是异步发电机运行中的重要暂态过程,对其进行分析可以为优化电机运行方案和合理设计电机保护措施提供理论支持。以异步发电机αβ0坐标系下的暂态等值电路为基础,列写异步发电机空载运行和带电阻负载运行情况下的自治状态方程。首先用非线性电路理论判断自治状态方程稳定性,再用4阶Runge—Kutta法分别求解投切负载时的状态方程,得到各状态变量的瞬时数值。把计算数据从αβ0坐标系转换到abc坐标系下,根据各时刻数值画出波形得到异步发电机投切负载时的暂态过程。给出相一致的实验结果和仿真计算结果,验证了所用分析方法的正确性。
Connection and disconnection of loads are the important transient processes in the operation of induction generators to be analyzed, which lays the theoretical foundation for optimizing operation scheme and designing rational protection manner. Based on the transient equivalent circuit under αβ0 reference frame, the autonomous state equations under no-load operation and resistive load operation of the induction generator are derived. With the stability of autonomous state equations firstly judged by the nonlinear circuit theory, these equations are then solved by the fourth-order Runge-Kutta method at connecting and disconnecting loads, respectively, from which the transient data are obtained. By transforming the data under αβ0 reference frame into those under abc reference frame, the transient waveforms are given. That experimental results are in agreement with simulation results verifies the correction of the presented method.