A Grid-connected Inverter with VAr Support Capability for A Small Scale Solar PV Using A Droop Technique

This paper presents a grid-connected inverter with VAr support capability implemented in a small scale solar PV system. This system is used to support reactive power balance in low voltage distribution network as the imbalance reactive power between supply and demand may increase energy losses in distribution lines. The reactive power control in this method adopts a droop technique. The control method includes phase-locked loop in order to confirm the synchronism between the inverter and grid. Besides, harmonics is one of the important issues in a grid-connected inverter and hence we should accommodate this problem in the controller design. Several experiments have been carried out to test the effectiveness of the design and the results show that the proposed design can be used as an alternative method of controlling VAr.