无速度传感器直接转矩控制系统的研究

发布时间：2018-03-30 12:50

本文选题：异步电机　切入点：直接转矩控制　出处：《西安科技大学》2017年硕士论文

【摘要】：随着新型电力电子器件的应用以及微型处理器的快速发展,交流变频调速技术得到了前所未有的发展,直接转矩控制技术以其简单的控制方法,优良的静、动态性能被广泛应用到各类电机控制中。高性能交流调速系统中转速反馈环节是必不可少的,实际应用中大多数采用光电编码器进行速度反馈,然而安装高精度的光电编码器将带来诸多不安全隐患。无速度传感器的应用将有效提高系统的工作效率,使系统硬件电路得以简化,因此,本文对无速度传感器直接转矩控制系统的工作原理以及控制方法进行了深入的研究。传统定子磁链观测器大多采用由积分器所构成的电压模型,该模型结构简单且只受定子电阻一个参数的影响,在高速情况下具有较好的观测精度。系统低速运行时积分器将产生直流偏置误差和积分初始值误差,进而影响定子磁链的观测精度,严重时将导致系统转矩脉动增大、电机低速性能变差。针对上述问题,本文采用一种带有幅值补偿的低通滤波器作为定子磁链观测器。模型参考自适应方法是实现无速度传感器技术的关键,传统模型参考自适应系统由转子侧变量构成,完全摒弃了直接转矩控制技术的优点。针对这一问题,本文采用了完全基于定子侧变量的新型模型参考自适应系统,以波波夫超稳定性理论为依据来推导其速度自适应率,并将改进的定子磁链观测器与直接转矩控制系统相结合。通过MATLAB/SIMULINK仿真来验证基于改进定子磁链观测器的新型MRAS转速估算系统的转速辨识精度以及鲁棒性。最后,本文以TMS320F28335为核心控制器进行系统的软、硬件设计。在对各个硬件电路分别调试以后进行系统的整体测试,通过实验结果可以看出,系统具有快速的动态响应能力。
[Abstract]:With the application of new power electronic devices and the rapid development of microprocessors, AC frequency conversion speed regulation technology has been unprecedented development, direct torque control technology with its simple control method, excellent static, Dynamic performance is widely used in all kinds of motor control. Speed feedback in high performance AC speed regulation system is essential. In practical application, photoelectric encoder is used for speed feedback. However, the installation of high precision photoelectric encoder will bring many hidden dangers of insecurity. The speed sensorless application will effectively improve the working efficiency of the system and simplify the hardware circuit of the system. In this paper, the working principle and control method of speed sensorless direct torque control system are deeply studied. The traditional stator flux observer mostly uses voltage model composed of integrator. The model is simple in structure and affected by only one parameter of stator resistance, and has good observation accuracy at high speed. The integrator will produce DC bias error and initial value error when the system is running at low speed. Furthermore, the observation accuracy of stator flux will be affected, and the torque ripple of the system will increase and the low speed performance of the motor will become worse when the stator flux is serious. In this paper, a low pass filter with amplitude compensation is used as stator flux observer. Model reference adaptive method is the key to speed sensorless technology. The traditional model reference adaptive system is composed of rotor side variables. Aiming at this problem, a new model reference adaptive system based on stator side variables is adopted, and the speed adaptive rate is deduced based on Popov's hyperstability theory. The improved stator flux observer is combined with the direct torque control system. The speed identification accuracy and robustness of the new MRAS speed estimation system based on the improved stator flux observer are verified by MATLAB/SIMULINK simulation. In this paper, TMS320F28335 is used as the core controller to design the software and hardware of the system. After debugging each hardware circuit separately, the whole system is tested. The experimental results show that the system has fast dynamic response ability.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP273;TM343

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