直接转矩控制的无刷双馈感应电机的异步启动

针对无刷双馈感应电机( BDFIM)异步启动电流及启动转矩的解析分析不足的问题,利用等效电路推导出BDFIM异步启动阶段两个定子绕组的电流和启动转矩的解析表达式.分析结果表明,功率绕组的启动电流小于同容量的感应电机.针对BDFIM直接转矩控制系统牵入同步时电流大的问题,提出了磁链优先的方法,即在牵入同步的过程中,根据控制绕组磁链所在的扇区,选择合适的电压矢量,优先建立磁链,待磁链增加到设定的阈值时,再兼顾磁链和转矩.样机的实验结果表明,磁链优先的控制方法能够有效减小两个定子绕组的牵入电流.

Asynchronous starting for BDFIM based on direct torque control strategy

For the problem that there is lack of the mathematical analysis for asynchronous starting current and starting torque of brushless doubly-fed induction machine(BDFIM),a detailed mathematical derivation of two stator windings current and starting torque of BDFIM in asynchronous starting was carried out based on the equivalent circuit.The analysis results show that compared with the induction motor with same capacity,the starting current of power windings of BDFIM is showed smaller;For the problem that the current is large while the BDFIM is pulled into the synchronization in direct torque control for BDFIM,priority is given to the CW flux control.That is,according to the sector which the control winding flux is in,the appropriate voltage vector was selected to give priority to establish flux while the BDFIM is pulled into the synchronization,the torque wouldn’t be considered until the flux increased to the threshold set.The experimental results on prototype show that the current of two stator windings is reduced effectively when the motor is pulling into synchronism by using the control method of flux priority.