The Design Of EV Charging Pile Control System Based On ?C/OS?

With the popularization of electric mobiles,the market of electric mobile charging pile is gradually expanding.The charging piles are developing towards the direction of more intelligence,standardized,humanized,and higher efficiency.The domestic popularizing rate of charging piles for public electric vihecles is still relatively low.With the introduction of the new charging pile national standard,some charging pile interfaces can no longer meet national standard.What's more,some small charging piles even have no data communication with other devices,and the intelligence level,maintenance efficiency and safety performance also need to be improved.To this end,a single-phase AC charging pile system was designed in this paper,which adopted module design,integrated with GPRS communication,electric energy measurement and control guidance,electrical protection and so on.Combined with the control software based on ?C/OS?,human-computer interaction interface based on EMWIN,calculation method of electric quantity based on algorithm optimization,the system can realize the electric vehicles automatic charging control,over-voltage over-current protection,high precision power consumption measurement,charging,uploading the fault data in real time,touch screen operation functions,etc.Not only improved the charging safety performance,also promoted the user charge maintenance experience and management experience.After conducting a preliminary research on the charging pile market,this paper introduced the current mainstream charging pile equipment technical parameters at home and abroad,and then proposed the technical function indicators of the charging pile system and the research content of this paper with the current charging pile market demand.Firstly,based on the theoretical analysis of the current electric energy measurement method commonly used in charging piles,a method of calculating power consumption was proposed through widowing FFT algorithm.Then the detailed overall scheme design of the hardware circuit of the charging pile system was carried out.According to different functional requirements,the hardware module was divided into auxiliary power module,main control chip module,electric energy metering module,radio frequency communication module and control guide module.Further,each circuit module as well as the safe and stable communication mechanism between the modules were designed.The software workflow for users was designed by using the ?C/OS? operating system as the underlying development environment of the software,and the functions of each control subroutine were divided reasonably.Moreover,based on the task control,process communication and memory management mechanism of the ?C/OS system,the core task was designed.Finally,the man-machine interaction interface and backstage management system of charging pile system were designed based on EMWIN interface library and LabVIEW graphics programming software.An experimental prototype of 220V/32 A,7KW,single-phase AC charging pile was developed in this paper eventually.Testing the various functions and indicators of the prototype and verifying the electric energy measurement algorithm through a hardware simulation,the practicability of the FFT algorithm with Hanning window in the field of power metering was validated by comparing the calculated data with the values directly read from the power metering chip.From the tested results,the charging pile system designed in this paper has generally met the functional requirements,but it also has some shortcomings and deficiencies,which will be further studied in the future.