A Novel Maximum Power Point Tracking Method for PV Module Integrated Converter

Solar cell has the current-voltage (I-V) characteristic which is affected by the radiation and the temperature. To obtain the maximum electricity from the solar cells, the power converters for PV (photovoltaic) module have a function called MPPT (maximum power point tracking). The dc voltage and current are controlled to track the maximum power point (MPP) where the PV modules feed the maximum output power. AC module is composed of a PV module and a module integrated converter (MIC). The output port is connected with the ac wiring. Each module can operate with tracking the own MPP. In case of AC module, the basic characteristic of the PV module is well-known by the manufacturer. Therefore the domain of MPP is approximately predicted. In this paper, a novel MPPT method for the MIC is proposed. The proposed method takes full advantage of the known PV module characteristic. The I-V plane is divided into two domains by a linear function. One includes MPPs and the other one never includes MPPs under the normal temperature and radiation conditions. The operating point can be rapidly approached to the MPP using the linear function. Around the MPP, the algorithm is switched to the IncCond method. Circuit experiments have been carried out. The measured time taken for the approach to the MPP is reduced from 22 % to 48 % compared to the conventional algorithm. The proposed method is quite simple so that it can be easily applied to various MPPT algorithms