Comparative Investigation of Grid– Connected PV Inverter Performance under Voltage Unbalance

B. K. Kimaiyo,C. Sirisamphanwong,S. Somkun,

Voltage unbalance in electricity distribution systems has become a power quality challenge especially with the increased uptake of distributed energy resources. In photovoltaic systems, voltage source inverters are a core component interfacing the electricity grid and the photovoltaic modules. And thus, they are constantly faced with grid voltage unbalance conditions, which may result in the presence of harmonics in the inverter current output and a double frequency component in its DC-link voltage. This study used a laboratory experiment to investigate the effects of voltage unbalance on the inverter efficiency, harmonics and current unbalance. It also measured actual grid voltage unbalance experienced by a photovoltaic system under operation at a pre-selected location. The study showed that voltage unbalance has limited effect on the inverter performance parameters and for the selected location, the voltage unbalance was less than 1%. This implies that at this particular location, voltage unbalance does not have adverse effects on the inverters based on the experimental results.

Volume 11 | 02-Special Issue

Pages: 777-785