【作者】 齐永龙；

【导师】 冯晓云；

【作者基本信息】 西南交通大学 ， 系统工程， 2003， 硕士

【摘要】 直接转矩控制技术一诞生，就以新颖的控制思想、简洁明了的系统结构、优良的动、静态特性受到了普遍关注并得到了迅速发展。本论文研究的就是基于DSP的全数字化的直接转矩控制系统。论文共分四个部分： 第一部分介绍了交流调速技术的发展，电力牵引技术的发展，分析了异步电机直接转矩控制的基本原理，推导了u-i、i-n两种磁链模型。并对这两种磁链模型的适应范围和特点进行了分析，然后推导了全速范围都适用的u-n模型。u-n模型的特点是：低速下工作于i-n模型，高速下工作于u-i模型，高低速之间自然过渡，加之引入电流调节器对电流观测值进行补偿，大大提高了模型的观测精度。 第二部分介绍了直接转矩控制在交-直-交电力机车牵引系统中的应用，并根据电力机车的牵引特性，在不同的转速范围内采取不同的控制策略： (1)低速区：采用圆形磁链的间接转矩控制； (2)高速区：采用六边形磁链的直接转矩控制 (3)弱磁区：通过改变磁链给定值来调节转矩，实现恒功率调节。 文中分别介绍了这三种控制方式的基本原理及各自特点，应用MATLAB/SIMULINK软件建立了直接转矩控制系统的仿真模型，并得出了仿真结果。 第三部分介绍了实验系统，该系统是由数字信号处理器TMS320C32为基础的控制电路，和由IPM模块为主的逆变电路所组成，并做了异步电机控制的开环SVPWM实验。 第四部分介绍了无速度传感器的直接转矩控制，推导了基于模型参考自适应(MARS)理论的转子转速的辨识方法，建立了转子转速的辨识模型，并得到了仿真结果，验证了该方法的正确性。更多还原

【Abstract】 Direct Torque Control (DTC) scheme has been widely studied and used during recent years due to its novel strategy, simple control structure and excellent dynamic and static performances. In this thesis, a direct torque control system of induction motor is studied. The thesis includes four parts.In the first part, the paper presents the developments of AC speed regulation technology and electric traction. It also analyzes the principle of induction motor direct torque control. The two stator flux observing models of u-i and i-n are derived , and the proper area and features of these two models are analyzed, then a u-n model which is suitable in the range of all speed is derived. The u-n model features: using i-n model in the low speed and u-i model in the high speed range. The transition between low speed and high speed can be smooth, as the current regulator can compensate the observed current, the precision of the observation is raised greatly.The second part mainly introduce the application of direct torque control in AC electric locomotive system. Based on traction characteristics of electric locomotive, the different torque control strategies are applied in the different ranges of speed:(1) Indirect torque control with circular stator flux in the low-speed range.(2) Direct torque control with hexagon stator flux in the high-speed range.(3) The torque is adjusted by setting different references of the stator flux in weaken flux area. The system power is invariable.The elementary principles and features of these torque control methods are introduced respectively. The simulation model of DTC is set up by using MATLAB/SIMULINK. And the simulation results are given which proves the feasibility of these control strategies.In the third part, the experimental system is introduced. The system mainlyincludes control circuit based on the digital signal processor (DSP) TMS320C32 and inverter circuit based IPM. The debugging and experimental research of open-loopSVPWM system have been done.Finally, the speed sensorless direct torque control is presented. The thesis deduces the identification method of rotor speed based on model reference adaptive system (MARS). The simulation model is set up and the results are also given.更多还原