宽功率范围内采用电流临界连续状态＋恒频控制的光伏微逆变器  

PV Micro-Inverter With Constant Frequency and Current BCM Control Strategy Within Wide Power Range

作　　者：阚加荣[1] 吴云亚[1] 谢少军[2] 汤雨[2] 吴冬春[1] 

机构地区：[1]盐城工学院电气工程学院,江苏省盐城市224051 [2]江苏省新能源发电与电能变换重点实验室(南京航空航天大学),江苏省南京市210016

出　　处：《电网技术》2017年第12期3926-3933,共8页Power System Technology

基　　金：国家自然科学基金项目(51577164);江苏省第五期“333工程”资助项目;江苏省“六大人才”高峰项目(XNY-045);江苏省前瞻性联合研究项目(BY2016065-47)~~

摘　　要：小功率微逆变器常工作于电流断续状态(discontinuous conduction mode,DCM),为提高效率,可将其设计工作于电流临界连续状态(boundary conduction mode,BCM),但需付出变频控制、过高的驱动损耗和开关损耗的代价。为克服上述问题,提出一种在宽功率范围内实现BCM的类谐振桥式微逆变器,引入可变电感作为能量缓冲器件,提出一种感值可扩展的方案,保证尽可能大的功率范围运行在BCM。提出一种BCM+DCM混合运行的控制策略,既保证了精度,又保证了动态特性。分析了所提方案在各方面的优势。350W实验样机验证了所提微逆变器性能优良。Low power micro-inverter is usually operated in discontinuous conduction mode（DCM）.For higher efficiency,it is designed in boundary conduction mode（BCM）.However,it must pay the cost for variable frequency,higher driving loss and switching loss.In order to overcome these shortcomings,this paper presents a full-bridge micro-inverter with variable inductance operated in BCM and constant frequency.A method for inductance extension is proposed for BCM in wide power range.A hybrid BCM＋DCM control strategy is presented for guaranteeing control accuracy and good dynamic performance.Experimental results of a 350 W prototype verify correctness of theoretical analysis in this paper.

关 键 词：桥式微逆变器 可变电感 感值扩展 电流临界连续模式 电流断续模式 

分 类 号：TM721[电气工程—电力系统及自动化]