Research And Realization Of Electronic Expansion Valve Controller For Electric Vehicle Based On

At present, the global climate and environmental problems are becoming more and more serious, and the car is becoming more and more obvious influence to the environment, therefore, the research of new energy vehicles is becoming more and more important. Electric vehicles as part of the new energy vehicles, has been rapid development in recent years, many major car manufacturers have joined the research production of electric cars. Electric car air conditioning is an indispensable part of electric cars, and air conditioning controller controls the entire air conditioning system, have a direct impact on life of electric cars. Electronic expansion valve controller is a part of the whole air conditioning refrigeration system, the research has a certain meaning, the existing electronic expansion valve controller are relatively independent in the air conditioning control system, in use process, when the air conditioning system parameters change, the controller is not easy to adjust for that application is not flexible, at the same time, the system structure is complex, high cost, according to the characteristics of this series, this paper research and design a kind of electric vehicle air conditioning electronic expansion valve controller based on FPGA.This article through to the electronic expansion valve controller needs analysis,also the controller control strategy and method are analyzed. For FPGA chip, temperature sensor, pressure sensor select models, and in the light of the characteristics of electronic expansion valve controller design and demonstrates the overall scheme. In this paper, degree of superheat control method are analyzed in detail, through pressure and temperature sensors measure the evaporator outlet and inlet temperature and pressure, the calculation and analysis of the relationship between temperature and pressure and degree of superheat, and find out the optimal control parameters by means of experiment, through the parameters selection for the control of valve opening, the optimization of PID algorithm control logic and control scheme of the integration, and use the American Altera company hardware development tool Quartus â…¡ the top design, the system of electronic expansion valve controller in C language of the electronic expansion valve controller system software development. This article detailed introduces the system main module, temperature acquisition module, pressure acquisition module, A/D conversion module, LCD display module and other hardware and software development process and program implementation, and the simulation waveform and some module for each module to test. Powerful function based on FPGA, design of electronic expansion valve controller embedded in the form of a modular air-conditioning controller of the whole. Through complete test and experiment, the results show that using electronic expansion valve controller as the master control chip FPGA system, compared with the traditional single chip or ARM, has small volume, short design cycle, portability is strong, and the advantages of online programmable, in the future, highly integrated and intelligent car electronic control system, using FPGA as the chip can effectively meet the on-board equipment module integration, more conducive to the miniaturization of system design, at the same time reduces the cost of car, and saves space for car interior.Finally, through the analysis of the performance of the controller and the control of electronic expansion valve, the characteristics of the controller are summarized and analyzed, and put forward to the prospect and expectation for the future.