A Novel Electrolytic Capacitor-less Micro-inverter with High Voltage Gain Power Decoupling Circuit

Abstract

Abstract:

A novel micro-inverter topology without electrolytic capacitor is proposed, which is applied in a single stage photovoltaic power conversion system. The topology is based on a conventional flyback combining with decoupling circuit located in the photovoltaic module output side. The power decoupling circuit can store the PV output power in high voltage capacitor, which reduces the decoupling capacitance, thus allowing for long lifetime film capacitor to be used. The flyback inverter uses the film capacitor as main power source and avoids interference with the photovoltaic module, which simple the control strategy of micro-inverter. Operation principle of the novel micro-inverter is analyzed in detail and the design principle of the main parameters is presented in this paper. A 100W prototype of the proposed micro-inverter has been built and tested. Experimental results are provided to demonstrate the validity of the proposed circuit and its control scheme.

Key words: Micro-inverter, electrolytic capacitor-less, power decoupling, flyback converter

CLC Number:

TM464

Zhang Chao,Wei Ting,Zhang Shuhui. A Novel Electrolytic Capacitor-less Micro-inverter with High Voltage Gain Power Decoupling Circuit[J]. Journal of Electrical Engineering, 2015, 10(4): 82-90.

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	解耦电容/μF	器件数目	控制方法	开关频率
本文拓扑	20	4开关管 +3二极管	简单	2高频 +2工频
参考文献18	40	4开关管 +3二极管	较难	2高频 +2局部高频
参考文献19	85	4开关管 +4二极管	较难	4高频
参考文献20	40	4开关管 +4二极管	复杂	1高频 +3局部高频
参考文献21	40	4开关管 +5二极管	复杂	1高频 +3局部高频

电路参数	数值
额定功率/W	100
最大功率点工作电压/V	30
最大功率点工作电流/A	3.3
开关频率/kHz	20
变压器匝比	64∶130∶130
C_pv/μF	50
C_D/μF	20
L_D/mH	0.15
L_M/mH	1

电路参数	器件型号
VD_S1、VD_S2	FR307
VD	RHRP3060
S_D 、S_M	HGTG30N60A
S_S1、S_S2	FGW40N120VD