Analysis on circulating current in parallel connected PV-inverters

Author

Liang Zhou ; Zhenxing Wu ; Guangsen Wang

Author_Institution

Nat. Key Lab. for Vessel Integrated Power Syst. Technol., Naval Univ. of Eng., Wuhan, China

fYear

2014

fDate

22-25 Oct. 2014

Firstpage

810

Lastpage

815

Abstract

This paper is focused on the analysis and reduction of zero sequence circulating currents for parallel connected inverters in high-power grid-connected photovoltaic (PV) systems. A zero sequence current may flow between the inverters due to the presence of solar panel parasitic capacitance to ground. The generating mechanism of circulating currents is analyzed in detail. Then, a zero sequence model is developed by the phase-leg averaging technique. Based on this model, a control strategy is designed to suppress the circulating current. Simulation and experimental results are carried out to validate the proposed control scheme.

Keywords

electric current control; invertors; photovoltaic power systems; power generation control; circulating current analysis; control strategy; high-power grid-connected photovoltaic systems; parallel connected PV-inverters; phase-leg averaging technique; solar panel parasitic capacitance to ground; zero sequence circulating current reduction; zero sequence model; Capacitance; Frequency control; Inverters; Mathematical model; Photovoltaic systems; Pulse width modulation; Switches;

fLanguage

English

Publisher

ieee

Conference_Titel

Electrical Machines and Systems (ICEMS), 2014 17th International Conference on

Conference_Location

Hangzhou

Type

conf

DOI

10.1109/ICEMS.2014.7013596

Filename

7013596