An Adaptive Constant Power Generation Control Scheme with Simple MPP Estimation for Photovoltaic Systems

With consideration of instability in environmental conditions, the increasing installation of maximum power point (MPP) operational Photovoltaic systems (PVSs) injects an unstable power generation to the grid (such as, overloading). Aiming to reduce the instable generation during continuous peak power generation, an adaptive constant power generation (CPG) algorithm is proposed in this paper. With the proposed control, the system can operate at MPP tracking (MPPT) mode or CPG mode with the detection from system operators. When the operation mode is detected, the control will operate with self-judgment including regulate the initial mode during CPG with a simple MPP initial MPP estimation. With the estimation of MPP and internal step-size regulation, the response speed, an important factor in variable environments, can be improved. In order to evaluate the proposed scheme, simulation and experiment in different condition, such as changing irradiation and changing limit power level are carried out.