A new maximum-power-point-tracking (MPPT) method for a photovoltaic (PV) power generation system was studied which can efficiently generate PV power even under changing weather conditions. In order to research a method suitable for the, actual photovoltaic power system, PV characteristics of the maximum power point were measured for more than six months using a PV curve tracer. The actual maximum power points vary with conditions such as the surface temperature and the quantity of solar radiation. So, relationships between the maximum power point and circuit variables such as open circuit voltage and short circuit current were examined under various conditions appearing in the PV power generation system. It was found through measurements that the relationship between the maximum power and the current that the output power was almost a linear function in the actual solar arrays, regardless of the weather conditions. The MPPT method was proposed based on the obtained findings. It was verified through simulations and experiments that the proposed method enables the solar arrays to quickly generate the maximum power as determined by weather conditions at the time.
