Photovoltaic systems analysis taking into consideration the shadows effect

摘要

This work studies the effect of shade on a 288kW Photovoltaic (PV) system installed in Royal Scientific Society (RSS) in Amman, Jordan. The study considers different patterns of dynamic shade; low, medium and heavy, different types of inverters; central, string and micro-inverter, and different series and parallel connections of the PV modules. A comparison regarding the cost is made, in order to choose the optimal connection for the whole system. A field test was made for a NU-SOE3E Sharp Module, to measure how the current and voltage change as the module was exposed to different patterns of shade; it was shown that if only one cell is under shade, the voltage drops by third. The study proved that for a large scale PV system under different types of shades, the output power of string inverters are higher than the output power of micro-inverters and central inverters. For a small scale PV system, the output power from micro-inverters is higher than from string inverters, but the comparison showed that PV systems with micro-inverters are more costly.