Design and Analysis of P & O and IP & O MPPT Techniques for Photovoltaic System

Photovoltaic (PV) energy is the most important energy resource since it is clean, pollution free, and inexhaustible. Due to rapid growth in the semiconductor and power electronics techniques, it is important to operate PV energy conversion systems near the maximum power point to increase the output efficiency of PV arrays. The output power of PV arrays is always changing with weather conditions, which mean solar irradiation and atmospheric temperature. Some MPPT techniques are available in that perturbation and observation (P&O) and improved perturbation and observation (IP&O). A P&O method is the most simple, which moves the operating point toward the maximum power point periodically increasing or decreasing the PV array voltage. It was proved that the P&O method control system sometimes deviates from the maximum operating point. When the MPP is reached, the P&O method will oscillate around it in case of constant or slowly varying atmospheric conditions. This problem can be solved to decrease the perturbation step; however, the tracking response will be slower. In case of rapidly changing atmospheric conditions, the P&O method can occasionally make the system operation point far from the MPP. Perturbation and observation (P&O) is that the operating point oscillates around the maximum power point (MPP).The improved P&O method is introduced, based on hysteresis band and auto-tuning perturbation step. There is trade-off between dynamic response and steady state due to the selection of “dv”. The Improved perturbation and observation (IP&O) has the tracking response will be higher. IP&O method has rapidly changing atmospheric conditions then the unpredictable performance with oscillations around maximum power point (MPP). In IP&O has high reliability and it is very complexity. A Mat labSimulink based simulation study of PV cell/PV module/PV array is carried out and presented.