A control strategy for a grid-connected PV system with unbalanced loads compensation

Photovoltaic systems plays an important role as a micro generators. These systems are normally near domestic loads that normally are unbalanced. Thus, a photovoltaic system that also compensates unbalanced loads is proposed. This system is implemented with a four leg voltage source inverter connected to the AC mains with accessible neutral. In order to control the AC currents a space vector based hysteresis controller in αβ0 coordinate system is used. A control algorithm that determines the references of the AC currents for compensate the load unbalance and transfer the generated by the photovoltaic panels is proposed. The performance of the proposed system is validated by several simulation tests. The obtained results show that the system can effectively transfer the energy from the photovoltaic panels and at the same time to compensate unbalanced loads.