Simulation and Analysis of Power-point Tracking via Photovoltaic Sensors

The photovoltaic (PV) cell is the basic component of a solar power system as it converts light energy into electricity by the PV effect. To increase the efficiency of conversion, the maximum power point (MPP) of the battery must be tracked in real time. We have established a system model based on the main characteristics of the PV power generation system and PV cells that considers the nonlinearity of the PV cell output. The mathematical model of a PV array is established by MATLAB/Simulink and combined with the common equivalent circuit of a PV cell and the mathematical model of PV power generation. This model enables the maximum power point tracking (MPPT) control of the PV cell through the simulation of its current-voltage (I-V) characteristic curve, which shows the cell's operation within its electrical circuit. We propose a MPPT control algorithm based on this model as an improved perturbation observation method. This algorithm controls the working current of the inverter of the PV cell using a PV sensor. Changes in light intensity or working temperature do not affect the ability of the tracking system to reliably track the MPP. This method does not need complex analysis and the control is based on a simple principle. Simulation results show that the algorithm has good dynamic performance in a steady state. The proposed method can track the MPP and improve the PV power generation efficiency by reflecting changes in illumination intensity with time.