Modeling of grid connecting photovoltaic generation system with improved MPPT algorithm

In this paper, photovoltaic maximum power point tracking (MPPT) algorithm based on duty cycle disturbing method is improved with a modified self-adopting step value calculation algorithm, the convergence of this modified tracking algorithm is speeded up compared with the original one and in the same time, numeric oscillation in the calculation process is avoided and the stability of convergence of algorithm is enhanced. A grid connecting photovoltaic generation system model has been developed with matlab/simulink, to fit for the using in power system phasor analysis, the converter is modeled in a reduced way in this system ensures that no power transferring variation will be led to. The MPPT algorithm is implemented with Matlab Simulink S 2 function and this will accelerate the calculating speed of simulation. To test the usability of modeled PV generation system in power system slow dynamic analysis, a simple power grid connected with PV system is constructed and simulation results show the effectiveness of this model.