光伏三电平逆变器高效断续空间矢量调制方法

A Novel SVPWM Method Considering Reducing Switching Losses for Three-level PV Inverter

针对中小矢量会对中点电位产生影响使其存在不可完全平衡区域,提出了一种在不同的负载特性下皆可实现中点电位平衡的不连续空间矢量调制方法。该方法将矢量分为对中点电位影响相反的两类矢量序列,采取切换矢量序列方式以此来实现中点电位平衡,可有效降低开关损耗。并通过搭建一台10kVA的光伏三电平并网逆变器样机对所提调制方法进行实验验证,证明了所提新型调制方法的可行性和有效性。

The medium and small vectors will affeet the neutral point potential which may cause the unbalance region of neutral point potential.For this problem,a discontinuous space vector modulation method is proposed to achieve the balance of neutral point potential under different load characteristics.This method divides vectors into two types of vector sequence that have opposite effects on the neutral point potential.And the switch vector sequence is applied to realize neutral point potential balance,which can effectively reduce switching losses.In addition,the experimental verification of the proposed modulation method is earried out through a 10 kVA photovoltaie three-level grid-connected inverter prototype to prove the feasibility and effectiveness of the proposed novel modulation method.