【作者】 赵智辉；

【导师】 刘和平；

【作者基本信息】 重庆大学 ， 电气工程， 2010， 硕士

【摘要】 在大力发展电动汽车的背景下,研究三轮电动车这类轻型小功率电动车可以为开发高性能电动轿车提供先见性的指导意见。在人民生活水平大幅度提高的今天,大众对集灵活、方便、节能、不污染环境、经济耐用等特点于一身的轻型代步工具的期待,也为新型三轮电动车的开发带来了巨大的潜在市场。尽管有众多电动三轮销售,但是大都没有抛弃笨重、低效的机械传动和转向装置,使得车辆的传动效率大打折扣,而电子差速正是解决这一问题的关键技术。论文分析了三轮轻型电动汽车的国内外发展状况及存在的问题。在对大量文献中电子差速方案进行调研的基础上,提出基于轮毂电机独立驱动的三轮电动车电子差速系统设计要求。本文对Ackermann-Jeantand的车辆转向经典模型进行了研究,并指出其欠缺对车辆转向时出现滑移现象的考虑。在深入分析三轮电动车在直线行驶、转向行驶和轮胎的动力学方程以及各驱动轮的转矩分配的基础上,尝试采用以滑移率为参考量,通过模糊控制对驱动转矩进行补偿的三轮车辆电子差速控制策略。论文用Matlab-Simulink仿真软件完成了三轮电动车差速控制系统的仿真模型建立和仿真实验验证。通过对直线运行、转向运行以及加速运行等工况中的直线扰动、大角度转向以及驱动轮滚动半径不同的情况进行仿真分析,得出了该方案能够对车辆的各种工况实施差速控制,有效的减少了后轮滑移,提高驱动系统的总体效率。电机是电子差速控制的执行单元,论文对无刷电机在电驱动车辆中的一些共性和特殊性进行了分析研究。总结了无刷直流电机中的四种PWM半桥调制方式,并确定采用PWM-ON进行电机调速;对三种常用的电机控制策略方式进行了简单的介绍,并最终选择采用力矩控制;特别针对电动车依靠蓄电池供电的特点,对永磁无刷直流电机低速回馈制动的机理进行了理论分析。论文完成了以dsPIC30F4012芯片为核心,采用三轮电动车电子差速控制方法的电机驱动控制器硬件设计。并将控制器嵌入到轮毂电机内,构成电机和控制器一体化的机构,并进行了换相电流跟踪实验。更多还原

【Abstract】 To study on low-power Light Electric Vehicles (LEV) such as three-wheeled electric vehicle in the background of increasing development of electric vehicle (EV) would be a necessity. The study could provide not only a prescient guidance for the development of high-performance electric vehicle, but also a enormous potential market for the expectancy to flexible, convenient, energy saving, environmental protective, economic and durable transportation instruments when people’s living standards are greatly improved currently. Despite the three-wheeled electric vehicle products in public are very normal and various, however most of them do not abandon the traditional mechanical transmission and steering device, which therefore cost battery power largely and should be the responsibility for vehicles’inefficiency.This thesis utilizes a dsPIC chip as MCU for three-wheels structure’s electronic differential (ED) system which controls the steering, transmission and speed synchronous, as well as driving the permanent magnet brushless DC motor (BLDCM).BLDCM is widespread adopt in low-power speed system such as electric three-wheeled vehicle because of its advantages at high starting torque, speed convenient, simple, high power density and easy to maintain. The paper firstly analyzes and studys on some particular issues of BLDCM driving system in detail. Then we make a brief presentation on both designing ideas and structure of the motor-driven controller.Aim to analyse the three-wheeled vehicle’s movement state, the dissertation offers an instruction of classical Ackermann-Jeantand model. After finding out its defect at lack of considering the slip rated while the vehicle is turning, this paper has a in-depth analysis at three-wheeled vehicle’s dynamic equations in both straightaway and turning condition, proves a tyre’s mathematic model, as well as the driving wheels’ torque distribution method. An ED control system, specially for three-wheeled vehicle, based on the slip rate is proposed afterwards.Subsequently, thesis takes slip rate as a reference fuzzy input to control the driving wheels’ longitudinal torque. Then it completes the simulation model of ED control system for three-wheeled vehicle in Matlab-Simulink platform. Using this model, the paper demonstrates the superiority of fuzzy control in ED system and well-performance of ED control strategy whether in straight driving condition or in a turn via relevant simulation results, which show the strategy can effectively reduce the rear wheels slip.After the demonstration and simulation analysis in the early, this paper designs an BLDCM driving controller with adopts the ED control system, which is especial for three-wheeled vehicles and uses dsPIC30F4012 as its core. Then this paper successfully carries on experiments of commutation current tracking at a controller embedded in-wheel BLDCM.更多还原