A New Maximum Power Point Tracking Scheme for Building Integrated Photovoltaic Systems

Building integrated photo-voltaic systems often operate under partially shaded conditions. Current versus voltage characteristics and power versus voltage characteristics of PV arrays are characterized by multiple steps and peaks under partially shaded conditions. Most of existing strategies always fail to track the real maximum power. On the basis of improving the conventional MPPT method perturbation and observation (P&O) and analysis of characteristic curves under uniform and non uniform solar irradiance, this paper proposes a novel algorithm combining the improved P&O method and scanning method to track the global power peak under partially shaded conditions for building integrated photovoltaic systems (BIPV). This algorithm has high efficiency and avoids oscillation. It has all the advantages of the P&O method, also may not fail into the global maximum power point. The control algorithm is verified to be effective by simulations.