Evaluation and analysis of transformerless photovoltaic inverter topology for efficiency improvement and reduction of leakage current. Issue 2 (1st February 2015)

• Record Type: Journal Article
• Authors: Cha, Woo‐Jun; Kim, Kyu‐Tae; Cho, Yong‐Won; Lee, Sung‐Ho; Kwon, Bong‐Hwan
• Is Part Of: IET power electronics. Volume 8:Issue 2(2015)
• Page Start: 255
• Page End: 267
• Publication Date: 2015-02-01
• Subjects: invertors -- leakage currents -- network topology -- equivalent circuits; transformerless photovoltaic inverter topology -- efficiency improvement -- leakage current reduction -- transfomerless PV inverter topology -- paralleled‐buck topology -- switching losses -- conduction losses -- free‐wheeling losses -- high‐frequency model -- leg voltage -- high‐frequency equivalent circuit -- parasitic capacitor voltage -- power 3 kW; Power electronics -- Periodicals; 621.31705
• DOI: 10.1049/iet-pel.2014.0401
• Languages: English
• ISSNs: 1755-4535

Abstract

Abstract : In transfomerless photovoltaic (PV) grid‐connected inverter application, to reduce leakage current and to increase efficiency, many inverter topologies have been proposed. The method for increasing efficiency and reducing leakage current is evaluated and analysed in the present study. The operation of transfomerless PV inverter topologies with high‐performance such as full‐bridge, H5, H6, HERIC and paralleled‐buck topology is analysed to calculate switching losses, conduction losses and free‐wheeling losses. Device total losses for inverter topology are calculated according to the switching frequency and the output power. Also, a novel high‐frequency model of inverter topology is proposed using the leg voltage and high‐frequency equivalent circuit. The relation between the parasitic capacitor voltage and its leakage current is explained using the proposed high‐frequency model. Also, the magnitude of the high‐frequency voltage in the parasitic capacitor is derived mathematically. Efficiency of the several inverter topology according to the output power is compared and the leakage current is analysed using a novel high‐frequency model. Finally, the efficiency and leakage current analysis are verified by simulation tool and 3 kW prototype.