光伏三电平逆变器高效断续空间矢量调制方法
|
摘要
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 affect 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 carried out through a 10 kVA photovoltaic three-level grid-connected inverter prototype to prove the feasibility and effectiveness of the proposed novel modulation method.
The medium and small vectors will affect 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 carried out through a 10 kVA photovoltaic three-level grid-connected inverter prototype to prove the feasibility and effectiveness of the proposed novel modulation method.
引文
[1] Nho-Van Nguyen,Bac-Xuan Nguyen,et al.An Optimized Discontinuous PWM Method to Minimize Switching Loss for Multilevel Inverters[J].IEEE Trans. on Industrial Electronics,2011,58(9):3958-3966.
[2]宋强,刘文华,严干贵,等.基于零序电压注入的三电平NPC逆变器中点电位平衡控制方法[J].中国电机工程学报,2004,24(5):642-651.
[3]胡存刚,王群京,李国丽,等.基于虚拟空间矢量的三电平NPC逆变器中点电压平衡控制方法[J].电工技术学报,2009,24(5):100-107.
[4]张志,谢运祥,乐江源,等.消除中点电位低频振荡的三电平逆变器空间矢量脉宽调制方法[J].电工技术学报,2011,26(3):103-109.
[5]姜卫东,杜少武,史晓锋,等.中点箝位型三电平逆变器空间矢量与虚拟空间矢量的混合调制方法[J].中国电机工程学报,2009,29(18):47-53.
[2]宋强,刘文华,严干贵,等.基于零序电压注入的三电平NPC逆变器中点电位平衡控制方法[J].中国电机工程学报,2004,24(5):642-651.
[3]胡存刚,王群京,李国丽,等.基于虚拟空间矢量的三电平NPC逆变器中点电压平衡控制方法[J].电工技术学报,2009,24(5):100-107.
[4]张志,谢运祥,乐江源,等.消除中点电位低频振荡的三电平逆变器空间矢量脉宽调制方法[J].电工技术学报,2011,26(3):103-109.
[5]姜卫东,杜少武,史晓锋,等.中点箝位型三电平逆变器空间矢量与虚拟空间矢量的混合调制方法[J].中国电机工程学报,2009,29(18):47-53.