笼形转子无刷双馈电机启动特性分析

无刷双馈电机在启动过程中受到功率绕组和控制绕组产生的异步转矩的综合作用,使得电机启动过程比较复杂,而采用合理的启动方法是改善BDFM启动性能的根本途径.在Matlab/Simulink环境下,利用BDFM的转子速坐标系下的d-q数学模型,对BDFM在不同启动方法下的启动性能进行了仿真分析,对比研究了异步启动、直流同步、亚同步以及超同步过渡过程中电流等参数的变化规律.研究结果表明:采用单馈异步启动的方法容易实现,但可能会产生较剧烈的振荡或失步现象,转动惯量和负载转矩等参数会影响电机异步启动后的稳定速度.双馈变频启动方法虽可实现平稳启动,但控制复杂.

Analysis of starting characteristics of cage-rotor brushless doubly-fed machine

The brushless doubly-fed machine(BDFM) is acted upon by asynchronous torques generated by power windings and control windings in the starting process.It makes the machine's starting course complex.The fundamental way to improve BDFM starting characteristics is to adopt the rational starting method.Based on the d-q model of cage-rotor BDFM in rotor speed coordinate,characteristics of BDFM under different starting methods are simulated with Matlab/Simulink.Laws of electric current variation are studied in the process of asynchronous starting,machine being pulled into synchronous by DC and being pulled into sub-synchronism and super-synchronism by AC.The results show that the method of single-fed asynchronous starting is relatively simple to implement,but commotion and out of synchronization exist.The BDFM's steady speed after asynchronous starting is mainly influenced by rotational inertia and load torque.The method of doubly-fed variable frequency starting can realize smooth and steady startup,however,its control is complex.