Experimental evaluation of the performance of grid-connected photovoltaic systems

This paper deals with the operation of grid-connected photovoltaic (PV) systems and provides a detailed performance comparison of different inverter technologies for connecting the PV systems to the grid. The requirements for inverter connection include maximum power point tracking, high efficiency, high power factor and low total harmonic distortion of the currents injected into the grid. In addition, island operation of the PV system must be avoided. Three PV systems have been experimentally studied. Performance comparisons are presented in terms of power quality indicators for a wide range of solar irradiance values and operating conditions, and of the inverter shutdown capability to avoid island operation.