【作者】 邹积勇；

【导师】 许镇琳；

【作者基本信息】 天津大学 ， 电力电子与电力传动， 2007， 博士

【摘要】 汽车工业是当今世界最大、最重要的工业部门之一,也是全世界大多数发达国家的支柱产业。由于电动机是电动汽车动力系统的核心,因此电动汽车的控制技术也必然是电动汽车核心技术之一。本文根据电动汽车的运行特性要求,以天津某电动汽车公司的具体项目为基础,研制了基于九千瓦异步电动机的电动汽车控制器ACEVC72-6。在此基础上对控制系统的整体效率、转矩的动态特性做了大量的研究和仿真工作,着重讨论了电动汽车在低速和启动时的大转矩快速跟随特性、中低速的节能特性、高速的快速弱磁特性以及再生制动控制策略的应用。根据电动汽车的使用特性要求,研究分析了全转速范围下的驱动控制策略和再生制动的机理、特性和控制策略。通过研究异步电机的调速方案,确定了电动汽车的基本控制策略为转矩闭环控制。提出电动汽车在平坦路面上中低速运行区段控制励磁优化效率,并基于损耗模型效率最优控制策略建立了数学模型。根据电动汽车本身特性及行驶特点的要求,结合变结构和转差频率矢量控制理论,以转速为切换对象进一步提出具有三种独立控制体系的变结构控制模型。低速时的恒磁通转差频率矢量控制策略能够保证电动汽车在低速启动时的转矩快速跟随性能;中低速时的变磁通效率优化矢量控制可以有效增加电动汽车的续航里程;高速时的变磁通最大转矩控制有效的改善了电动汽车提速性能。深入分析异步电机数学模型及自抗扰控制技术,利用自抗扰控制技术设计了控制系统的电流调节器。基于q轴电流调节器,搭建了速度扰动函数模型及结构框图,完成对异步电机速度的估计。自抗扰控制器不依赖于控制对象的模型,利用扩张观测器准确估计系统中的扰动,克服异步电机高次非线性强耦合及参数随温度变化的特性,能够实现异步电机控制系统的准确解耦和高性能控制。以二象限DC-DC直流斩波器驱动结构为模型,解析分析了PWM电路的微观过程,在能量回馈制动方面做了大量的研究。提出一种适用于电动汽车的再生制动控制策略—恒定回馈电流控制,并在理论上推导了恒定回馈电流控制的数学模型和克服再生制动系统工作死区的边界条件控制方程,分析了制动能量回馈效率与电机反电动势和回馈电流的关系。最后,通过MATLAB/SIMULINK仿真软件对各种控制方案和再生制动策略分别进行了仿真研究和对比,得出各种控制策略能够提高电动汽车性能的结论。同时将仿真结果与实验室和台架实验系统的实验结果做了相应的研究与比较,进一步验证了上述控制策略的可行性。更多还原

【Abstract】 Automobile industry is one of the largest and the most important industry all the world, and it is also the main support industry in almost every developed country. Because motor is the core of the electric vehicle power system, naturally the motor’s control technology is the core technology in the field of electric vehicle. According to the traits of electric vehicle in this paper, on the basis of a practical project of Tianjin EV Co., we developed an electric vehicle controller ACEVC72-6 for a nine kilowatts asynchronous machine. In terms of high efficiency some works about dynamic torque and field weakening were done by simulations, and there are some emphases on quick torque respond, economizing on energy and maximum torque in the field weakening.According to the application traits of electric vehicle drive control strategy and regenerative brake strategy were studied in the range of whole speed. On the basis of analyzing sorts of asynchronous machine’s control strategy, the basic control strategy made is torque closed-loop control. Mathematic model on optimizing control strategy in medium speed was put forward on the basis of loss model, and this strategy was completed by controlling excitation. On account of electric vehicle’s own traits and running characteristics, combining with variable structure control (VSC) theory and variable frequency vector control theory, a novel VSC model with three independent control algorithms was put forward further. Variable frequency vector control strategy of constant flux guarantees the quickly dynamic torque in low speed. The efficiency optimization vector control strategy of variable flux increases the running distance of electric vehicle in medium speed. Maximum torque control strategy of variable flux effectively promotes the acceleration traits in high speed.Based on the comprehensively deep research on the AC induction machine mathematic model, a novel speed and current regulator, the active disturbance rejection controller (ADRC), is proposed to achieve high performance AC induction machine drive, which has great ability of adaptation and better performance against disturbance. What’s more, speed estimate was completed from the current regulator as above. The active disturbance rejection strategy is independence of plant models.ADRC is composed of three parts, tracking differentiator, extended state observer and nonlinear state error feedback control law. By using the extended state observer, the AC system has stronger robustness, which can overcome nonlinearity and coupling of the parameters of AC induction machine. Also, it can surmount parameters excursion caused by temperature change.Due to the model of DC-DC chopper in two quadrants, some researches of regenerative brake were done in this paper, and the microcosmic course of PWM circuit was analyzed. On this basis, a novel regenerative brake control strategy adaptable to electric vehicle was put forward-constant feedback current control. The mathematical model of constant feedback current control and control equations of overcoming regenerative brake’s dead zone were calculated. The relations of feedback efficiency of brake power, back electromotive force of motor and feedback current was studied.Finally, sorts of control strategies and regenerative brake strategy were simulated by MATLAB and got some good conclusions. At the same time simulation and experimental results were compared and studied, the control stratigies above was proved feasible further.更多还原