【作者】 鲁木平；

【导师】 曹承志；

【作者基本信息】 沈阳工业大学 ， 检测技术与自动化装置， 2004， 硕士

【摘要】 直接转矩控制(DTC)是20世纪70年代提出的，是继矢量变换控制技术之后，在80年代中期发展起来的一种新型的高性能的交流调速控制技术。目前该技术已成为交流调速传动中的一个热点，本文正是针对这一技术进行了一些较为深入地研究。 为了实现异步电动机高性能的无速度传感器直接转矩控制，必须准确知道电机转速和定子电阻等参数，基于这一点，本文提出了用小波神经网络(WNN)的方法，来构造对定子电阻和转速进行辨识的小波神经网络系统参数辨识器，阐述了小波神经网络的结构并且对小波神经网络的算法，即梯度下降法、基于正交最小二乘法和在线辨识的递推正交二乘法等方法进行了认真的比较、分析 本文从异步电动机模型出发，构造了具有小波神经网络辨识器的直接转矩系统的仿真模型，从仿真结果可以看出，采用小波神经网络的转速辩识器代替DTC系统中的速度传感器，实现DTC系统无速度传感器的方案是可行的、有效的；同时，加入了小波神经网络的定子电阻辨识器的直接转矩控制系统其低速性能还有明显的改善。 本文对无速度传感器直接转矩控制系统的接口电路，包括实现小波神经网络辨识器算法的数字信号处理器(DSP)系统开发的硬件电路，以及对六边形磁链轨迹控制PWM方法和直接转矩控制方案进行了设计和研究。 最后有理由确信，小波变换与神经网络等智能技术的相互交叉、相互渗透，会给无速度传感器直接转矩控制系统的最终稳定运行和准确控制奠定可靠的基础。更多还原

【Abstract】 one method of AC induction motor control called Direct Torque Control (DTC),which was raised in 1970’s .has been developed rapidly in the middle of 1980’s and is a powerful control method for motor drives. Following the vector control technique, the quick development of DTC makes itself a new high performance AC driving technique paralleling to the vector control. Now the technique in AC driving is studied widely. In this thesis the author made a study of technique.To fulfill high performance direct torque control of an induction motor, it is necessary to know precisely parameters of induction motor, such as rotor speed and stator resistance. So wavelets and neural network are combined and wavelet neural network (WNN) is proposed. Through WNN identifier, stator resistance and rotor speed are identified. In this paper, wavelet neural network configuration is expatiated and its algorithm is analyzed. At last conjugate gradient method and orthogonal least squares algorithm and on-linear identification recursive orthogonal least squares algorithm are proposed.According to induction motor principle, simulation model of direct torque control system with wavelet neural network identifier is built. Simulation result reveals that DTC system with WNN identifier showed excellent static and dynamic performance. So through using speed identifier with WNN replacing speed sensor on the DTC system, the scheme with no speed sensor is effective and feasible, and direct torque control system with WNN stator resistance detector resolved low speed performanceFinally. We developed a hardware system based on Digital Signal Processor (DSP), and to the system can run steadily, we designed the scheme of direct torque control and study the PWM method controlled by the hexagon flux trace.According to this paper, we can believe that the combination of wavelet transform and neural network will advance the development of intelligent control science and detection technology.更多还原