The Research On MPPT Technology And Energy Management System Of PV Electric Vehicle Based On Embedded System

With the increasing of global energy crisis and public awareness of environmental protection,photovoltaic(PV)power generation technology,electric vehicle technology and PV electric vehicles have been developed rapidly.However,the photoelectric conversion efficiency of PV cell is low in and the output characteristic is nonlinear.In addition,the overall output power of photovoltaic arrays is low and unstable because of uneven illumination and partial shading.The traditional power system of photovoltaic electric vehicle is only supported by the battery.Such supply results in the shortcoming,such as un-durable supply,short battery life,short endurance mileage,and so on.These problems have seriously restricted the efficiency and reliability of photovoltaic electric vehicles.The specific research contents of this paper are as follow:1)Simulink is used to simulate the traditional photovoltaic array centralized MPPT.During the simulation,we found that its output power reduced seriously under partial shading.A distributed MPPT voltage matching scheme is proposed and simulated.The simulation result shows that the scheme can effectively mitigate the effect of partial shading on the output power of photovoltaic arrays.2)The prototype of MPPT controller is designed and manufactured based on STM32 embedded chip.The preliminary test,contrast experiment and centralized MPPT experiment.Three groups of experiments all show that the controller can effectively improve the output power of PV battery with high performance.Then,the distributed MPPT voltage matching scheme is tested to solve the problem of partial shading.The experiment result shows that the proposed scheme can effectively improve the output power of photovoltaic arrays by comparison of centralized MPPT.3)The control strategy of battery charge and discharge is designed with droop control technology.The simulation model of the energy management system is built,and three groups of simulation are carried out under the condition of load change,illumination change and synthesis.The simulation result shows that the system can realize the complementary power supply mode of PV-battery with good stability.The results above show that the photovoltaic MPPT controller is with good performance.The distributed MPPT voltage matching scheme can effectively improve the output power of photovoltaic arrays under partial shading,and the energy managementsystem can make the maximum use of the output energy of photovoltaic arrays and realize the PV-battery hybrid technology and increase the endurance mileage of electric vehicles.