Research On Solar Charging Station System For Unmanned Electric Vehicle

In recent years, on one hand, due to the fossil fuels like coals and oils being utilized frequently, the environmental problems such as haze, gas pollution and global warming gradually have intensified increasingly. On the other hand, due to the subside policy and several supports made by governments around the world, electric vehicles will be of the top priority of the future in the field of new energy. Therefore, it will be of practical value to research on the solar charging station on electric vehicles.Taken the campus electric car as the research object, an intelligent control system of solar charging station for electric vehicle is designed in this paper, which has two functions:firstly, electric vehicles and/or storage devices are charged with photovoltaic array; secondly, electric vehicles are charged with the storage devices. The work is accomplished in this paper are as follows:1) Through the study on development and applications of electric vehicles and Solar photovoltaic power generation technology, and analysis on the constitution of Off-grid solar power system, the overall design of intelligent solar charging station system for unmanned electric vehicles is put forward, which is based on the combination of software-control of DSP and hardware-control of PWM chip. Then the design process of per module is elaborated.2) According to the overall design and technical indexes, the parameters of PV modules and storage batteries required for this system are calculated, which contain the number of solar panels needed and their series-parallel connection way and the capacity of batteries. On this basis, the hardware of this system is designed, which include charge-discharge module, driving module, power supply module, DSP minimum system module and its peripheral circuits and sampling and control module, then the PCB is made and tested.3) Based on the software development environment of CCS4.12, the software of this system is designed in use of C language. Through analyzing charge-discharge principle and several kinds of charging ways, the charge-discharge process is programmed and the three-stage charging management process is described in detail. Through analyzing the principle of maximum power point tracking and different MPPT algorithms to improve the precision of tracking, an improved P&O algorithm in variable steps during different stages is programmed, so as to efficiently utilize the power conversed by solar cell modules.4) Based on the above, charge-discharge prototype is built for the charging station system, and the hardware testing is made on each module. The feasibility of the driving circuit are tested to be feasible. And it is proved that charge-discharge performance of main circuit which works under the discontinuous-mode could output stably, thus to ensure the feasibility of this system.