基于载波移相控制的脉冲整流器直流侧支撑电容电压谐波抑制研究

Research on DC-Link Capacitor Voltage Harmonics Reduction of PWM Rectifier Based on Carrier Phase-Shifting

以电力牵引交流传动系统中两重化脉冲整流器拓扑为研究对象,以实现其直流侧支撑电容电压谐波抑制为目标,首先从理论上分析了直流侧支撑电容容量的设计方法;然后分析了稳态运行时直流侧电压高次谐波的产生机理,并重点分析了两重化脉冲整流器载波移相控制方法对直流侧脉动的影响。理论分析表明直流侧电压高次纹波主要分布在2倍开关频率附近,载波移相控制技术可以有效地抑制直流侧2倍开关频率附近的纹波电压,从而减小直流侧电压纹波系数。因此在传统直流侧支撑电容容量设计方法的基础上,加入载波移相控制可以进一步减小所设计的支撑电容大小。最后对未添加载波移相控制和添加载波移相控制的方法分别进行了计算机仿真和半实物试验测试。Matlab仿真和dSPACE半实物测试结果都验证了理论分析的正确性和有效性。

In the paper, to reduce the DC-link capacitor voltage harmonics of dual-cascading PWM rectifier in electric traction AC drive system, firstly, the theoretical design method of DC-link capacitor was introduced, then, the characteristic of high order harmonics of DC-link voltage in the steady-state was derived, and DC link voltage ripple of the dual-cascading PWM with carrier phase-shifting technology was analyzed in detail. The theoretical analysis showed that the high order ripples of DC-link voltage were mainly distributed around the twice switching frequency, and the carrier phase-shifting technology could reduce these high order ripples to suppress the DC voltage ripple coefficient. Therefore, the DC-link capacitor could be minimized based on traditional design method in combination with carrier phase-shifting technology. Control methods with and without carrier phase-shifting technology were compared in computer simulation and hardware-in-theloop（HIL） experiment system respectively, which showed the validity and effectiveness of theoretical analysis.