NPP结构新型五电平变换器

A Novel Five-level Converter Based on NPP Structure

针对二极管中性点箝位五电平变换器直流侧串联电容电压平衡困难问题,提出了一种中性点可控(NPP)五电平变换器。该拓扑的每相电路都由两个结构相同的NPP三电平变换器组合而成,与传统的中性点箝位五电平变换器相比,具有模块性强、电容电压平衡容易等优点。首先详细地分析了其基本原理和工作模态,然后介绍了其空间矢量脉宽调制(SVPWM)算法和电容电压平衡控制算法,最后通过实验验证了电路的可行性和控制算法的正确性。

To solve difficulties of series capacitance voltage balance in direct current side of neutral point clamped five-level converter,a novel neutral point piloted（NPP） five-level converter is proposed.Each phase of the circuit to- pology consists of two identical NPP three-level converter.Compared with the traditional five-level diode clamped con- verter,the new topology is simple to construct, easy to balance the capacitor voltage.Its principle is detailed analyzed, working process are introduced, and then describe in its space vector pulse width modulation （SVPWM） algorithm and balance control of capacitor voltage.Finally the feasibility of the proposed topology and control strategy is validated by the experimental results.