【作者】 吴志刚；

【导师】 南余荣；

【作者基本信息】 浙江工业大学 ， 控制理论与控制工程， 2004， 硕士

【摘要】 异步电机的直接转矩控制系统以其思路新颖、控制方案简单及性能优越等特点受到人们的普遍重视。本文对异步电机的数学模型进行详细研究，并构建了直接转矩控制仿真系统，对直接转矩控制方法的特点及其存在的问题进行深入的理论和仿真研究。 由于直接转矩控制存在的不足之处主要在于转矩脉动，特别是在低速运行时这种情况更加突出，针对该问题，本文提出了一种离散时间空间矢量合成法来改善转矩脉动，并且引入滑模理论，设计了一种滑模转矩和磁链控制器来克服这一缺点。另一方面，定子磁链的观测准确性，是直接转矩控制技术实现的关键。本文对传统的定子磁链模型进行详细分析，并提出了一种滑模定子磁链观测器，该模型结合了定子磁链常用模型的优点，对电机参数变化的具有很好的鲁棒性。 无速度传感器技术的研究是一个很重要的方向。本文研究了基于卡尔曼滤波算法的速度辨识法和基于异步电机模型的模型参考自适应法，针对模型参考自适应法提出了一种PI自适应速度辨识法。并通过仿真研究证明了该方法的有效性。在此基础上，实现了无速度传感器的直接转矩控制系统。 作为一种高性能的交流调速系统，在直接转矩控制系统中，速度调节器通常都采用PID调节器，使得系统的快速性和抗干扰能力及对系统参数扰动的鲁棒性不够理想。本文设计了一个基于滑模变结构控制的速度调节器，使得系统具有更好的鲁棒性和动、静态性能。并且基于滑模控制理论设计了滑模转矩和磁链调节器。仿真结果表明该方法的可行性。更多还原

【Abstract】 Direct torque control (DTC) system for induction motor has got wide attention with the advantages such as its new thoughts, simple control scheme and excellent performance. In this thesis the author made a study of asynchronous motor model, designed a hybrid simulation system of DTC and analyzed the characteristics of the DTC system and the existing problems detailedly.Due to the large torque ripple of induction motor in DTC system, especially in low speed, this thesis proposed a discrete time space vector modulation and designed a sliding-mode torque and flux controllers based on sliding-mode theory to overcome this drawback. On the other hand, the preciseness of stator flux estimation is the key to DTC technique, the conventional stator observation models are detailly analyzed in this thesis, and the author proposed a sliding-mode stator flux observation, which integrates the advantages of the normal models and has high robustness again the motor parameters varieties in DTC system.The study on speed sensorless is an important research field. The methods for speed identification based on Kalman filter and model reference adaptive system are deeply investigated in this thesis, a new PI adaptive method of speed identification based on MRAS is put forward. And the simulation will testify the effectiveness. Finally a speed sensorless DTC system is carried out.The DTC system is a high-performance AC driving system. But conventional speed controller in DTC system is PED adjuster, which can’t make the system have enough quick response, the ability to restrict the noise and strong robustness to theparameters of the system. So the author designed a speed regulator based on sliding-mode control theory, which make the system has strong robustness to the parameters, excellent dynamic and steady-state performance. Then a torque and flux regulator based sliding-mode control theory was designed to reduce the torque ripple in conventional DTC system. Simulation results show the method is effective.更多还原