一种基于改进单相Y源逆变器的功率解耦方法

A Power Decoupling Solution Based on Improved Single-Phase Y-Source Inverter

基于改进单相Y源逆变器,提出了一种新型功率解耦方法。由于二倍频功率纹波的存在,会在单相逆变器直流母线侧产生电压和电流纹波。通常情况下,会在全桥逆变器的直流侧并联大容量电解电容来实现前后级功率解耦。然而,电解电容体积大、寿命短,会影响光伏系统的可靠性和寿命。因此,利用改进Y源逆变器来实现功率解耦,该方法只需要分别在全桥中点和两个桥臂之间增加一个解耦电容。同时对应的控制策略确保在不影响负载电压的情况下,功率波动完全转移到两个解耦电容上。最终,搭建了一台基于TMS320F2812的200W的实验样机来验证所提功率解耦方法的有效性。

This paper proposes a power decoupling solution based on improved single-phase Y-source inverter. Single-phase inverter would cause voltage and current ripples on dc link because of double-frequency power ripple. Commonly, large electrolytic capacitors are connected to dc link in H-bridge inverter to accomplish power decoupling. However, electrolytic capacitors would affect reliability and lifetime of PV systems. Therefor, the improved Y-source inverter is utilized for power decoupling instead, with only two capacitors added between midpoint and each inverter arm. A corresponding control method is proposed to ensure the power ripple transferring towards the two decoupling capacitors without affecting output voltage. Finally, a 200 W laboratory prototype is built based on TMS320 F2812 digital signal processor to verify performance of the proposed power decoupling solution.