单相三电平脉冲整流器模型预测直接功率控制

A Model Predictive Direct Power Control of Single-phase Three-level PWM Rectifiers

该文以CRH_2(China railways highspeed-2)型高速电动车组牵引整流器为研究对象,以提高整流器响应速度和控制精度为研究目标。首先,给出整流器在d-q同步旋转坐标系下的数学模型,并给出d-q轴坐标分量的计算方法;然后,建立单相整流器瞬时功率数学模型,进而提出一种具有直流侧电容电压平衡功能的模型预测直接功率控制(model predictive direct power control,MP-DPC),在此基础上,为降低该算法的复杂度,提出一种简易开关序列选择方法,与基于比例积分调节器的传统直接功率控制(proportional integral-based direct power control,PI-DPC)算法相比,该MP-DPC算法不仅提高了整流器的动态响应速度,而且考虑了中点电位的平衡控制对整流器瞬时功率的影响,无需功率内环PI控制器;最后,对该MP-DPC算法与传统定频PI-DPC算法进行了半实物实验对比验证,实验结果证明了所提控制算法的正确性。

In order to improve the controller＇s dynamic responsibility and control accuracy of the single-phase three-level rectifier applied in China railways highspeed-2 （CRH2） electric multiple units （EMU）, firstly, a mathematical model of the rectifier in d-q axis synchronous rotating reference frame was shown, and a calculation method of the d-axis and q-axis components was presented. Secondly, the instantaneous power mathematic model of single phase three- level rectifiers was discussed, and then a model predictive direct power control （MP-DPC） method embedded with direct current （DC） link capacitor voltage balancing was proposed, on the basis of this, a simple selection scheme of the switch sequence was adopted to reduce the algorithm complexity. Compared with the traditional proportional-integral-based direct power control （PI-based DPC） method with constant switching frequency, the proposed MP-DPC can improve the dynamic response of the rectifier, consider the influence of neutral point voltage balance on the instantaneous power, and be free of tuning and design the power inner loop PI controllers. Finally, the proposed MP-DPC and the traditional PI-based DPC schemes were compared and verified in hardware-in-loop experiment platform. The experimental results verify the validity of the proposed MP-DPC scheme.