Design And Development Of Application Program Based On Qt For Electric Vehicle Charging Pile

The year of 2014 marks the beginning of electric vehicle. It is the milestone of electric vehicle industry, which also indicates the popularization electric vehicles in the next few years. AC(alternating current) charging pile, as the energy supply equipment, plays a key role in the promotion and industrialization of electric vehicles. With the development of science and technology, AC charging pile is becoming a kind of public facility as well as intelligent terminal. Therefore, man-machine interface shows great significance in the design of the pile.The paper focuses on the man-machine interface of AC charging pile from the perspective of software,aims to design a set of man-machine interface program of AC charging pile under the framework of Qt. The author puts forward some main technical indexes of application designing based on the current standard of charging pile designing in China. Then through modular design, the corresponding function modules are realized, such as electric energy metering, wireless communication, personal identification, charging monitoring and control, etc. Also, after comparing different output schemes, the author finally adopts Qt to control the PWM wave that has adjustable output duty ratio. With the control circuit integrated into the main control circuit, the software thus can simplify the overall hardware construction of the charging pile. The PWM wave accurately reflects the current value with the ratio of 0.6A/ 1% duty cycle, which is in accord with national standard.After the program designing, functional verification is carried out. The verification results show that the program can 1) take effective control and provide a safe and convenient charging environment; 2) real-timely display the information of electric energy with a updating rate of 300 ms, which is lower than the standard of transmission response delay; 3) provide permanent online network communication and keep real-time data exchange with the remote server to realize remote monitoring and management. To conclude, the program is complete in function, convenient in operation and also good in extension capability, which shows its value in the research and development of charging pile.