感应电动机的电源快速软投入技术及其初始瞬态解析

感应电动机在短时间断电后，对于转速仍然保持在同步速附近的情况，其重新投入电源的过渡过程表现为短暂的电磁瞬态，该文提出基于电力电子开关控制的电源快速软投入技术，可以在0.1 s内快速投入电源而不产生瞬态电流冲击，其控制策略不同于针对较长机电动态过程的软起动控制。为实现软投入控制的快速性，采用解析方法推导出瞬态电流与触发角等控制参数之间的关系。对于软投入控制中所出现的感应电机两相和三相交替的瞬态过程，分别建立基于ab 0坐标系降阶的不对称瞬态数学模型和与之相关联的基于空间向量复数变量的对称瞬态数学模型，使解析求解得以简化，从而快速求出初始触发角，进而构成触发角序列，最终得到完整的软投入控制策略，通过仿真和实验予以验证。

Rapid Soft Re-switching Technique of Three-phase Induction Motors and Its Initial Transient Analytical Method

If the induction motor could keep rotating near rated speed or synchronous speed after power supply is lost for a short time, the re-switching dynamic behavior presents as brief electromagnetic transient. The rapid soft re-switching technique on base of power electronic switches could realize the re-switching rapidly without the inrush current within 0.1 s, which control strategy is different from soft start aimed at longer electromechanical transient. In order to realize the rapidity of soft re-switching, the analytical method is applied to deduce the relationship between transient current and firing angle. As for the transient course that two phase windings connecting and three phase windings connecting are alternated each other, the reduced unbalanced transient model in αβ0 reference frame and the balanced transient model expressed with space vector are established respectively. So the analytical solution could be simplified and the initial firing angles are determined rapidly. Finally, the complete rapid soft re- switching control strategy composed of sequence of firing angles is verified with the simulation and experimental results.