【摘要】 为解决二极管中点钳位型三电平逆变器直流侧中性点电压不平衡问题,提出了基于60°坐标系的空间矢量脉宽调制算法。该方法采用参考电压矢量标幺变换和扇区旋转模型以简化SVPWM算法;同时根据中性点电流方向和上、下电容电压差,设计PI控制器,调节冗余小矢量作用时间以平衡中性点电压,并在不同调制比下分析了该算法对中性点电压的平衡控制能力。最后利用搭建的Matlab仿真模型和实验平台验证了该算法的有效性。更多还原

【Abstract】 A space vector pulse width modulation(SVPWM) algorithm based on 60° coordinate system is presented to solvethe unbalance of voltage in the DC side of a diode-clamped Three-Level Inverter. The SVPWM algorithm is simplified bythe per-unit transformation of the reference voltage vector and the model of sector rotation. The PI controller is designedaccording to the direction of the mid-point current and the voltage difference between upper and lower capacitor. Theaction time of redundant small vector is adjusted to balance the mid-point voltage. In addition, the ability of the algorithmto control mid-point voltage at the different modulation ratios is analyzed. The performance of the algorithm is verifiedthrough Matlab simulation and experimental platform.更多还原