消除谐波电流的七相感应电机矢量控制

Vector Control of Seven-Phase Induction Motor with Harmonic Currents Elimination

为了实现对七相感应电机磁链和转矩控制,同时消除定子谐波电流,根据减小空间解耦模型谐波子空间中合成电压矢量的原理,提出了3种消除定子谐波电流的方法,即3次谐波子空间合成矢量为0的SVPWM(space vector pulse width module)A法、3次及5次谐波子空间合成矢量同时为0的SVPWM B法和通过电机闭环控制的UVM(unified voltage module)C法.采用负载调速实验验证了3种控制方法对七相感应电机磁链和转矩的控制效果.结果表明:SVPWM A法和SVPWM B法,在调制深度和转速调节过程中,依靠调整施加矢量顺序和作用时间来实现消谐,效果不理想;UVM C法通过增加谐波子空间电压为0的约束条件,实现闭环控制,消除谐波电流效果较好,在基波含量为52.5 dB情况下,3次和5次谐波含量很低,仅为17.8和9.8 dB.

In order to control the flux and torque and eliminate harmonic status currents of sevenphase induction motors simultaneously,three methods were proposed according to the principle of reducing the harmonic subspace composite voltage vectors in the space decomposition model. These methods included the space vector pulse width module（SVPWM） A where the composite voltage vector of the 3rd harmonic subspace is zero,the SVPWM B where the composite voltage vector of the 3rd or the 5th harmonic subspace is zero,and the unified voltage module（UVM） C that adopts a closed-loop motor control strategy. Speed-regulating experiments were then performed to verify the efficiency of the three methods in control of the flux and torque. The results show that the performance on harmonic currents elimination using SVPWM A or SVPWM B is not satisfying,since only the action time and sequence of voltage vectors are adjusted while the modulation depth and motor speed are changing continuously. However,a closed loop control of motor is realized under the constraint that harmonic space voltage is zero; therefore,the harmonic currents were eliminated remarkably using UVM C.Compared with the fundamental content（52. 5 dB）,the 3rd and 5th harmonic contents are very small,only 17. 8 and 9. 8 dB,respectively.