一种新型三相Buck-Boost光伏逆变器漏电流抑制研究

RESEARCH ON LEAKAGE CURRENT SUPPRESSION OF A NEW T HREE-PHASE BUCK-BOOST PHOTOVOLTAIC INVERTER

摘要: 漏电流问题是限制非隔离型光伏逆变器广泛使用的关键因素之一。为解决该问题，提出一种可应用于光伏系统的新型三相Buck-Boost逆变器。首先介绍该逆变器的拓扑结构和工作原理，然后推导该拓扑在任意开关时刻共模电压的表达式，从而研究正弦脉宽调制（SPWM）和系统共模电压及漏电流之间的关系，并通过数学模型分析逆变器的升降压能力。最后通过实验平台对上述方案进行验证，实验结果证明了上述方案的有效性和可行性。

Abstract: The common mode current is one of the key factors limiting the widespread use of transformerless PV inverters. Thus,A new three-phase Buck-Boost inverter which can be used in solar PV systems is proposed in this paper to solve this problem. This paper firstly introduces the topology of the inverter,analyzing its working principle,deriving the expression of its common-mode voltage at any operating mode. The influence of the Sinusoidal Pulse Width Modulation（SPWM）on common-mode voltage（CMV）existing in this inverter and leakage current are then analyzed. Finally,the above scheme is verified by the simulation and experimental setup.According to the results and data from the experiments,this new inverter is effective and feasible.