The Design Of Charging Pile With Distributed Photovoltaic Power Station

A series of problems caused by fossil energy prompt humans to explore renewable energy,the matter covers pollution,non-renewable and imbalance between supply and demand. As a typical representative of renewable energy, solar photovoltaic is widely applied in production and living for its pro-environment and abundance. Electric Vehicle(EV) is vigorously promoted and supported by government as an important measure of renewable energy application. The quantity and coverage of charging device provide a strong and firm support to the healthy development of EV market. The version of pollution-free of EV will break if electric supply comes from thermal power plant. Enormous increase of EV will be beyond the capability of utility grid and the process of charging will affect the power quality. The use of solar photovoltaic to charge the EV can perfectly resolve above problems.In this study, quite a few scattered PV panels are incorporated into a DC bus and electric energy of PV panels is concentrated to charge the EV. Technology of Maximum Power Point Tracking(MPPT) is used to extract more power from the PV panel. The voltage of 400 V on DC bus is fixed by VIENNA rectifier. Full bridge converter acts as the main circuit of charging pile and the charging voltage and current is adjusted by instructions of controlling chip. An adaptative perturbation and observation method is used as MPPT control method and the PID control method is realized by software to control the charging circuit.VIENNA rectifier and full bridge converter are simulated based on PSIM software. The simulation results show that the output voltage of VIENNA rectifier reaches a stable level at 400 V with a tiny fluctuation and the output voltage of full bridge converter stabilize at 380 V. This study also accomplish the simulation comparison between traditional P&O method and adaptative perturbation and observation method by the Matlab/Simulink and the result shows that adaptative perturbation and observation method has a better performance.A parallel test has been made with three Boost circuit nodes connected with PV panels, the output voltage is clamped to the DC bus voltage of 46 V. The test result shows that each circuit node operate stably and the method of self-adapting disturbance variable is effective. A constant current constant voltage(CCCV) charging test is accomplished on a piece of 24 V lithium-ion battery and different States Of Charge(SOC) is analyzed. The working condition is analyzed of a grid inverter connected with a solar array, shows the correlation between irradiance, input and output current and voltage.