Power System Of Electric Vehicle Matching Design And Performance Simulation Research

With the rapid development of Chinese automobile industry and the growing of the dependence for foreign petrol, the energy supply and economic security issues have caused serious concern of the government policy-making departments, business and academic circles. At the same time the increase of population has been serious, we must begin the energy-saving and emission reduction right now. At this time the electric vehicles technique, which has important social value and far-reaching strategic significance is facing rare development opportunities in China This thesis introduce the current situation of Chinese electric vehicles first, then illustrate the strategic significance of the development of pure electric vehicle and the development trends of pure electric vehicles in china and abroad. And also points out the problems and the gap with foreign countries in electric vehicle development process. However, there is still hope to catch up the developed countries.This paper first details the basic structure and key technique of electric vehicle The structure of electric vehicle consists of power drive control system, chassis, body, and various auxiliary devices etc. Except for the power drive control system, the functions and structure of other parts are similar to traditional cars, so the structure and performance of pure electric vehicle are depended on the power drive control system, which is also the focus of this paper. Then, it gives emphasis to motor control system, batteries and management systems and light vehicle technique. There are varieties of advanced technology used on the pure electric vehicle. For example, the energy saving effect has been constantly improved because of integrated optimization technique on power system; high-performance lithium battery instead of traditional lead-acid batteries; electric auxiliary systems are widely applied to improve the energy efficiency and vehicle performance; As network is widely used, they promote vehicle to modularity and intelligent; weight light technique and electrical systems security technique have been applied. These key techniques related to mechanical, dynamic, electrochemistry, electric machinery, microelectronics and computer control and many other subjects of high technology.This paper emphasizes on UFO, which is a representative of urban leisure SUV. It has many advantages, such as ride comfort, energy economy, convenient operation, and comfortable space etc. It's a typical representative in current economical and urban leisure SUV vehicle market. UFO has its own characteristic in urban leisure vehicles, it has the comfort of sedan and the shape of SUV, and it highlights strong young breathing. So the pure electric SUV will attract the eyes of young consumer and has wider market.The structure of vehicle is front-wheel drive, drive systems, battery management systems, and most of the power batteries are put in the front of body, to balance the weight of vehicle, a small part of battery are in the rear of body, the motor is put in the original position of engine, still use the internal combustion engine drive system, and remove the clutch and other reduction gear, to use fixed reduction ratio can reduce the weight of mechanical transmission device, and reduce the volume. The structure becomes more simple and reliable. In the operation we still use original main control device and control method of internal combustion engine vehicle, which is easy used by the driver, it makes the operation simple and standardized. The electric drive system consists of motor, fixed speed ratio and differential. Reversing can use electronically commutated motor system. Steering and braking system is extended to connect with both ends of the Deputy motor shaft and the motor drives them to work. The other structures of electric vehicles are same with conventional fuel vehicles.According to the traditional calculation of vehicle dynamic performance and through the analysis of various resistance in travel process this paper proposes a more practical method to let drive systems design matching. First we need confirm the electric vehicle driving mode, and determine the performance requirements of the electric drive parts according to dynamic performance indicators and the technological level of parts. On the basis of the analysis conditions to offer the performance indicators of electric vehicle, and the parameter value of the power system is chosen according to the dynamic performance of electric vehicle. In theory, to evaluate if the program meets the design requirements and objectives, and then to amend performance of the front part, repeat the process above until you reach your desired destination.Finally, by means of computer simulation we verify the system parameters matching results and propose optimization solution. From the simulation results, this method is reasonable and effective.This paper take the SUV model UFO as a archetype, to offer the dynamic performance requirements of electric vehicle, take parameter match for the power system, and also make the parameter matching design for the motor, gear ratio, battery capacity and other key parameters. To make detailed design and description of the type of drive motor, the motor rated voltage, rated power and peak power, the motor rated torque and maximum torque, the motor base speed and maximum speed and other parameters. To calculate the maximum and minimum power train reductions ration in theory and use a simple and reliable fixed reduction ratio. The type of battery system of choice, batteries voltage and energy choice is also carried out reasonable design and matching.This paper introduces focused on the main functions and practical significance of the simulation software ADVISOR (Advanced Vehicle Simulator). To use software to simulate the dynamic properties of cars will supply a quick and economical way for the car design or development, and also can shorten the product development cycle, then enable designers to select the best option from many designs. Computer simulation offers you a accurate, fast and effective tool for the prediction of vehicle dynamics, and eliminate the actual vehicles on the road test roads to environmental factors that influence on the determination of the car performance, it has the advantage of good comparability, strong repeatability and so on.We use ADVISOR software to build simulation model, and use ADVISOR to emulate power system matching and performance of electric vehicle. It will help our company to select the power system matching and performance of electric vehicle during the actual operation, to give theoretical explanations and improvement, the test results show that the conclusion of power system design and performance simulation of electric vehicle is correct.This paper analyzes the vehicle model,motor model,battery model and transmission model, and make the electric car modeling and simulation through ADVISOR, which is based on MATLAB platform. Through the ADVISOR to the vehicle dynamic performance and renewal drove mileage simulation the top speed, acceleration time and climbing ability completely meet the design requirement. The trip mileage is simulated by Uniform speed method. The simulation results meet design requirements.At the same time we also analyzed the factors that affect electric vehicle's dynamical performance, they are the weight of vehicle, the drag coefficient, rolling resistance coefficient, transmission ratio, the mechanical properties of the motor and battery discharge characteristics, etc.; the factors that effect electric vehicle's trip mileage are the rolling resistance coefficient, air drag coefficient, the weight of vehicle, vehicle efficiency, battery capacity, driving conditions, ambient temperature, the auxiliary electrical components and so on. And also make simulation on various factors that effect vehicle's dynamical performance and trip mileage, then get the most reasonable matching parameters of the power system and optimize the results of vehicle dynamic performance and trip mileage.Through the ADVISOR simulation, the dynamic performance of electric vehicle meets design requirements, and achieves the desired power performance and trip mileage. The torque and speed characteristics of drive motor system can meet the dynamic performance of electric vehicles. Battery capacity can meet the requirements of vehicle trip mileage. To check the vehicle performance, we also make the road test; test results completely meet the design requirements. It provides a certain reference value for the electric vehicles future design.