NPC三电平静止无功发生器SVPWM简化与改进

分析了应用较多的二极管箝位型三电平静止无功发生器主电路原理,着重探讨了三电平SVPWM技术的简化与改进。提出将不同扇区中的三电平参考空间矢量经过旋转、加减运算、再旋转的方法,最终都转化为同一个固定扇区内的两电平参考矢量来进行合成运算,从而实现了三电平SVPWM算法的简化,减轻了主控制器的运算负担。提出了以SVG交流侧瞬时电流为根据修正SVPWM脉冲序列中正、负小矢量作用时间,在控制直流中点电压平衡的同时避免了增加系统的硬件电路,实现了三电平SVPWM算法的改进和优化。仿真和实验结果证实了该SVPWM简化、改进方法的正确性和有效性。

Simplification and Optimization of SVPWM for Three-level SVG

This paper analysed the operation principle of the main circuit of the three-level SVG which is baesd on the commonly used diode-clamped three-level inverter.The paper discussed the simplification and optimization of three-level SVPWM.It proclaims a method to simplify the three-level SVPWM by transferring three-level space vector in different zones into two-level space vector in the same zone by rotating the vector twice.It also puts forward the optimized method of three-level SVPWM by adjusting the working time proportion of the equivalent positive and negative small vector in a space vector pulse train,it can be effective to balance the neural point voltage at DC side. The result of the simulation and experiment show that the simplification and optimization method of three-level SVPWM is correct and effective.