Research On Photovoltaic Power Generation Efficiency With Complex Shadows Analysis And Global Maximum Power Point Tracking Control Technology

Solar photovoltaic(PV)power generation technology has important practical significance to mitigate the energy crisis and reduce environmental pollution.In this paper,aiming at the problems of low efficiency of PV system,the theoretical analysisd,simulation research and experimental verification of PV module modeling and Maximum Power Point Tracking(MPPT)control,complex shadow PV power generation efficiency analysis and global MPPT control technology are carried out.In this paper,the physical simulation model and engineering simulation model of PV module under uniform illumination are established.The influence of internal parameters,illumination intensity and temperature on the output characteristics of the module are analyzed.The relevant conclusions are obtained.In order to improve the efficiency of PV power generation,MPPT control technology needs to be adopted.Aiming at the problem of tracking "dead zone" existing in traditional variable step-size P&Q algorithm,an improved variable step-size P&Q algorithm is proposed to automatically adjust the step coefficient.The experimental results show that the algorithm improves the tracking performance of the system.PV cells cause a temperature increase in the shade,and it will cause the hot spot effect in the serious case.In this paper,the hot spot effect experiment of PV module is carried out,and the method to solve the hot spot effect in engineering is discussed.The local shading simulation model of PV modules and arrays is established.The effects of different shading coefficient,area and position on the characteristics of the module are studied by considering the influence of illumination intensity reduction and temperature rise under shading.The output characteristics and power of the array under the complex shadow are analyzed,and the relevant rules are summarized.The principles and steps of the optimized configuration of the photovoltaic array in engineering are obtained.By setting up the experimental platform of PV cell output characteristics,the experimental research on the output characteristics of PV modules and arrays under uniform illumination and shielding is completed and the conclusion of the simulation experiment is verified.Under local shading,the output characteristics of PV array show multi-peak characteristics.The traditional MPPT algorithm can track the failure.In view of the problems of slow convergence speed,low tracking accuracy and easy falling into local optimum for the application of Particle swarm optimization(PSO)algorithm to PV MPPT,a PSO algorithm based on individual location mutation is proposed.The algorithm significantly increases the convergence rate under the premise of expanding the particle search range.The simulation results show that the proposed improved PSO algorithm can track the global MPPT quickly and accurately with no shadows,static shadows and dynamic shadows and operate stably.Finally,a set of MPPT experimental platform of PV system based on DSP28035 is designed.The MPPT and global MPPT algorithm are tested.The experimental results show that the improved algorithm has good tracking performance,which achieved the expected control effect and has a good promotion and application value.