Maximum Power Point Tracking And Control Scheme For PV Systems Under Partially Shade Condition

With the rapid development of economy and the growing population, human dependence on energy is more and more obvious.Diminishing fossil fuels even dried up at the same time, and the increasing deterioration of the environment makes human face a serious energy crisis,and the development of renewable energy is imminent.With the constant improvement of photovoltaic power generation technology,Solar energy is a green renewable energy and get the attention of people greatly. This paper mainly studies maximum power point tracking algorithm under partial shade,and the control of DC/DC converter and grid inverter PQ control and so on.Start from the following aspects:This paper builds PV equivalent circuit and mathematical model under uniform illumination and partial shade.and sets up PV array simulation model.and analyzes output characteristic of the different light intensity and temperature.The output characteristics are simulated under uniform illumination and partial shade.And this paper analyzes the characteristics of its peaks.The respective advantages and disadvantages of Genetic algorithm,BP neural network and improved PSO-fuzzy neural network algorithm are analyzed.On the basis of it,TLBO based on PSO-improved fuzzy neural network is proposed.The initial value setting range and "Teaching" and "learning" phase coefficient of TLBO is improved.Its convergence speed, accuracy and stability is significantly improved.In view of the chattering of SMC,ITLBO-SMC is proposed.ITLBO-SMC and SMC is used for modeling and simulation,and compared to the simulation results,it is proved that the proposed ITLBO-SMC is superiority,and it can be more fast tracking to the maximum power point,and has a smaller overshoot and adjustment time.PSO-Prony algorithm of chattering detection is proposed.and the basic principle and parameters solving process of PSO-Prony algorithm is analyzed.By the harmonic curve fitting test,the performance of the PSO-Prony algorithm is superior in stability, precision and antinoise performance.PSO-Prony algorithm was applied to the chattering wave elimination of SMC.and the maximum power point tracking output value is a constant.PQ control simulation model is established,and the effectiveness of the PQ controller is verified by simulation.At last, the PV array model with MPPT access to PQ controller,and the corresponding simulation model is established to realize interconnection PQ control. With MPPT PV array are verified effectiveness with PQ control.