| With the aggravation of environmental pollution and the increasingly shortage of energy,energy saving and emission reduction have become the theme of the development of Automotive Technology in today’s society.Although electric vehicles can solve the problem of environmental pollution well,there are still many shortcomings in their own.Therefore,as a smooth transition vehicle of the pure electric vehicle,the range extender vehicle has received extensive attention.It has the advantages of high efficiency,low battery requirements,high endurance and high mileage.Due to the influence of the speed of the range extender on the charging and discharging of the battery,the extended-range electric vehicle also raises new requirements for the selection and control strategy of the range extender.The EFI(electronic fuel injection)technology plays a great role in energy saving,emission reduction and speed control.The FAI electric injection system is a new type of EFI system,which was developed for the electronic injection technology of small gasoline engine.In order to make the range extender stablely operatate.The application of the FAI EFI system on the range extender was explored in this paper.In this paper,a digital speed regulation system which is suitable for the range extender was explored.In order to achieve the stable operation of the range extender and meet the control requirements,the control strategy and parameter calibration were analyzed and studied.First,referring to the V development mode of the electronic control system,the engine and electronic throttle models were built by using GT-power and Matlab/Simulink software.In the Simulink environment,the engine GT-power model and the electronic throttle model were coupled,and the threshold weakening integral PID control was designed,and the control effect was simulated and analyzed.According to the optimized control strategy,we optimized the software and hardware of the digital speed regulation system.The signal processing circuit,the signal sampling circuit and the motor drive circuit were given,and the detailed design of the software was given,including the idle speed module,the acceleration module and the constant speed control module etc.Secondly,according to the practical application needs of the range extender,we optimized the host computer system on the basis of the original system.We select the DATAVIEW,which was developed by FAI,as the platform.The CAN communication module and the MAP data module were optimized.The diagnostic module and the analog instruction sending module were rewritten.FAI calibration method was used to calibrate the relevant MAP of ignition and fuel injection of the engine after retrofit.Finally,the speed regulation characteristics of the speed control system were tested.The test results show that the range extender can guarantee the successful start in the cold and heat engine condition,the idle speed can be controlled at 2000±100 r/min,and the speed fluctuation can be controlled in the range of 50 r/min under the constant speed conditions.The speed fluctuation is basically controlled within the range of 100 r/min in the transition conditions.After changing the target speed,the speed is stable at 3s.Under all working conditions,the response characteristic of the throttle is good and the response time is less than 1s.Finally,according to the experimental results,the advantages and disadvantages of encounter limit weaken the integral PID control strategy were analyzed.According to the conclusion of the test,the application of FAI EFI system on the range extender can achieve the relevant control requirements. |
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