阐述了双Y移30°永磁同步电动机电压空间矢量脉宽调制(pulse width modulation,PWM)技术的2种矢量选择方式,提出一种新颖的空间矢量过调制技术。过调制区域根据调制度分为4种模式。在过调制方式Ⅰ和Ⅱ中,对z1-z2电压平面上的电压矢量采用不同的优化策略。依据电压输出矢量自身的特性,提出了一种易于DSP实现的寻找次优解的方法。为进一步提高直流母线电压利用率,过调制方式Ⅲ和Ⅳ采用两电压矢量调制,不再对z1-Z2电压平面上的电压矢量进行优化。通过仿真计算,对输出电压的波形和谐波成分进行分析。构造基于低功耗定点数字信号处理器TMS320F2812的7.5kW双Y移30°永磁同步电动机控制系统。实验结果证实提出方法的正确性和可行性。
Two approaches to space vector control of dual Y shift 30 degree permanent-magnet synchronous motor were elaborated. In addition, a novel over-modulation technique for space vector pulse width modulation (SVPWM) inverter was proposed. The over-modulation range was divided into four modes depending on the modulation index. This method adopted different optimization algorithm to voltage space vector on z1-z2 plane in mode Ⅰ and Ⅱ. Depending on character of voltage output vector, this paper presented a DSP implementation of finding sub-optimal solution method easily. In order to further improve voltage utilization ratio, the paper adopted two voltage vectors modulation in mode III and IV, which no longer optimized voltage vector on zl-z2 plane. Output voltage and harmonic components were analyzed by simulation. A 7.5 kW dual Y shift 30 degree permanent-magnet synchronous motor control system was set up based on a low-cost fixed-point TMS320F2812 digital signal processor. Experimental results demonstrated the effectiveness and feasibility of the proposed method.