A Study on Behavior of Power Conditioning System for Photovoltaic Generator Outputting Large Power

When a large-capacity photovoltaic generator is connected to a distribution line, the output voltage of the power conditioning system (PCS) for the photovoltaic generator can decrease as the output power increases. This can cause the power reversed from the PCD to the distribution system to be limited to a certain value Plimit. This phenomenon occurs more easily in the case where the impedance from the distribution substation to the interconnection point of the photovoltaic generator is large. The behavior of the PCS under such a situation was investigated by computer simulation and experiment. As a result, it is revealed that the PCS becomes uncontrollable when the output power of the PCS approaches Plimit.