CAJ | 학술논문

针对传统光伏系统存在热斑、整体效率低等问题，提出了一种高效率、低输入电流纹波的隔离型单相两级式光伏并网微逆变器。该微逆变器由前级 DC/DC 升压环节和后级逆变环节组成。DC/DC变换器采用有源钳位和倍压整流电路，使变压器原边开关管及副边整流二极管实现软开关，分析了其稳态下的工作原理并给出了变换器关键波形曲线；后级逆变环节应用软件锁相、脉宽调制等技术实现了逆变并网。提出了一种低成本的在中间母线电压环中加入扰动环节的方法，抑制了两级式逆变器直流输入侧存在的两倍交流输出频率的电流纹波。研制了一台220 W光伏微逆变器样机并进行了测试，实验结果证明了理论分析的可行性。
침대전통광복계통존재열반、정체효솔저등문제，제출료일충고효솔、저수입전류문파적격리형단상량급식광복병망미역변기。해미역변기유전급 DC/DC 승압배절화후급역변배절조성。DC/DC변환기채용유원겸위화배압정류전로，사변압기원변개관관급부변정류이겁관실현연개관，분석료기은태하적공작원리병급출료변환기관건파형곡선；후급역변배절응용연건쇄상、맥관조제등기술실현료역변병망。제출료일충저성본적재중간모선전압배중가입우동배절적방법，억제료량급식역변기직류수입측존재적량배교류수출빈솔적전류문파。연제료일태220 W광복미역변기양궤병진행료측시，실험결과증명료이론분석적가행성。
As the traditional photovoltaic inverter system has problems like hot spot,low efficiency and so on,a high-efficiency,low input current ripple of isolated single-phase two-stage photovoltaic grid-connected micro-inverter is proposed.It is composed of two stages:the first stage is the DC/DC boosted link,and the second stage the inverter link.Based on the principle of active clamp and voltage double rectifier,this micro-inverter realizes soft switching on both the transformer primary side switch tube and secondary side rectifier diode,analyses the principle of working in the steady state and gives the key waves of the converter.In the inverter link stage,soft phase-locked and pulse width modulation(PWM)are applied to achieving grid-connection.This paper also presents a new low-cost method by incorporating a ripple cancellation duty ratio in the control duty ratio of the DC/DC converter to reduce the AC ripple current with double output frequency existing on the DC input side of the boost-buck converter.A 220 W photovoltaic micro-inverter prototype is developed and tested,the experimental results have verified the feasibility of the analysis.