适用于电动汽车的PMSM宽转速最优PAM控制

Wide-speed-range Optimal PAM Control for PMSM Used in HEVs

脉宽调制电压型逆变器(PWM-VSI)主要用于变速永磁同步电机(PMSM)驱动中。然而,当PMSM端电压超出直流母线电压时将无法工作。这里提出一种优化的脉冲幅度调制(PAM)控制方法,利用Buck-Boost DC/DC变换器来调整逆变器直流母线电压。考虑到电动汽车上应用需求,该变换器还可实现功率的双向流动。在低速范围内,该系统能减小电压指令的总谐波失真,使电枢电流波形得到改善,转速范围得到扩展。为验证所提出的方法,最后给出了实验结果。

PWM voltage source inverter（PWM-VSI） is used for the variable speed permanent magnet synchronous motor （PMSM） drives.However, PMSMs cannot operate at the speed which the motor terminal voltage exceeds voltage constraint imposed by the DC-link voltage.Because of this,the armature currents are distorted and then the torque ripple increases.Consequently,higher DC-link voltage influences the speed control performance at the low speed range.This paper proposes an optimal pulse amplitude modulation（PAM） control which can adjust the inverter DC-link voltage by using the Buck-Boost DC/DC converter.Further, considering the electrical vehicle application,the converter enables bi-directional power flow.At low speed range, the proposed system can reduce the total harmonic distortion （THD） of the voltage commands,and then the armature currents waveforms would be improved.Also,the allowable speed range would be extended.In order to verify the proposed method, the experimental results are presented.