【作者】 刘述喜；

【导师】 王明渝；

【作者基本信息】 重庆大学 ， 电气工程， 2005， 硕士

【摘要】 在工业生产和控制中,测功机应用非常广泛。鼠笼式异步电机转子轻、高速性能好、结构简单、可四象限运行,是全功能型测功电机的首选品种;电力电子技术及微电子技术的飞速发展推动了电机控制技术的发展,电机的控制性能大大提高。直接转矩控制技术是继矢量控制技术之后提出的又一种新型的交流电机调速理论,与矢量控制技术相比,其主要优点在于它摈弃了矢量控制中的解耦思想,直接对电机的磁链和转矩进行控制,具有控制直接,计算过程十分简化的优点。运用直接转矩控制方式、使用鼠笼式异步电机构建全功能型交流测功机系统是一种较理想的解决方案。本文深入研究了异步电动机直接转矩控制方法的基本原理,分析了直接转矩控制系统的系统结构,详细阐述了电压空间矢量、磁链与转矩的观测、磁链和转矩的协调控制等直接转矩控制的基础理论,说明了磁链和转矩的脉动与滞环宽度的关系及其优化控制策略。为了抑制启动电流和故障过电流,提出一种电流滞环控制方案。在MATLAB 环境下建立了感应电机直接转矩控制系统及测功机系统的仿真模型,对所提出的控制策略和算法进行了全面的仿真研究,取得了良好效果。最后,本文选择鼠笼式感应电机作为负载电机,负载电机与驱动电机同轴相联,采用公用直流母线方式,以高速TMS320LF2407A DSP 控制芯片和高速IPM模块为主体器件构建了测功机系统平台,进行实验研究。论文详细介绍了硬件控制电路的实现,和与之对应的控制系统的软件的编写方法,实现了直接转矩控制系统的全数字化控制。仿真和实验结果表明,采用鼠笼式异步电机作为负载电机、以高速DSP 作为控制芯片、运用直接转矩控制技术对其实行转矩控制的测功机系统具有控制结构简单、给定转矩调节方便、快捷、系统转矩响应迅速、电能可通过共用直流母线形式或回馈单元回馈电网等一系列优点,是一种值得推广的新型测功机之一。更多还原

【Abstract】 In industrial production and control area, the dynamometer is widely used. For full-function type dynamometer, squirrel cage induction motor is firstly chosen due to its light rotor, simple and rugged structure and four-quadrant operation. The development of power-electronics and micro-electronic technologies greatly pushes the development on the control techniques of AC motors, the control performances of motors are greatly improved. The direct torque control (DTC) technology of induction machine is a new theory for AC drive following the vector control technology, in contrast to vector control, its main advantage is that it discards the decoupling idea in vector control, controls the motor’s flux and torque directly. Its control is easy and the calculating process is very simple. Employing the control method of DTC, using the squirrel induction motor to construct a full-function AC dynamometer system is a better solution scheme. In this thesis the basic principle of the control method of direct torque of the asynchronous motors is further investigated and the systematic structure of the DTC is analyzed. Also this thesis expatiates many basic conception of DTC in detail, which include the voltage space vector, the estimator of flux and torque, harmonious control of flux and torque. The relation between the ripples of flux and torque and the widths of hysteresis band is analyzed and its optimum control strategy is suggested. In this thesis, a kind of current hysteresis band control scheme is presented in order to control the stator current in a limited range at star-up and faulty overcurrent. And then a series of simulation models of DTC of induction machine and dynamometer system under the environment of MATLAB are established to perform all simulations for the proposed control tactics and algorithms, better effect is obtained through simulations. Finally, this thesis selects a squirrel cage induction machine as the load motor, which is linked with the driving machine through a rigid coupling and the DC sides of the main circuits of the two machines are in common DC-bus. The hardware platform of the power dynamometer based on high-speed digital signal processor (DSP) TMS320LF2407A as the controller and intelligent power module (IPM) as the main devices is constructed for experiment studies. This thesis explains the realization of hardware control circuit in detail and the corresponding control system software compiling method. The full digital control of direct torque control system was established. The results of simulations and experiments show that, the dynamometer system which uses squirrel cage induction machine as the load motor, high-speed DSP as the controller, DTC based, has following virtues such as simple structure, the given torque adjusting conveniently and swiftly, the response of the system being quick. Further more, the energy can feed back through common DC-bus or regenerating unit to the networks, it’s one of new type dynamometers which is worth to be broadened.更多还原