基于二阶滑模MRAS的异步电机无传感器控制策略研究

发布时间：2019-01-09 12:48

【摘要】：随着社会经济的快速发展,能源紧缺和环境污染问题日益突出。近年来,电动汽车作为一种清洁、高效的交通工具越来越为人们所重视。而电动汽车的运行性能主要取决于其驱动电机的运行性能,这促使了对进一步发展、完善电机控制技术的需求。矢量控制技术的发展以及异步电机低成本、免维护、宽调速范围的突出优点,使得异步驱动系统在电动汽车中得到了广泛应用。在电动汽车中,速度传感器的安装不仅增加了系统控制成本,同时振动、电磁干扰的恶劣环境也影响了转速信号检测的可靠性。因此无速度传感器矢量控制技术成为高性能电动机驱动系统的必备技术,而其技术的核心在于转速和磁链观测。同时磁链的准确观测对矢量控制的性能具有决定性的意义。本文围绕异步电机基于转子磁场定向的无速度传感器矢量控制技术展开研究,主要对速度和转子磁链观测这两大核心内容进行深入研究与分析。首先从异步电机数学模型出发,对间接磁场定向和直接磁场定向两种典型矢量控制方案进行了简要讨论。其次,针对传统模型参考自适应系统(MRAS)转速辨识方法存在的问题,研究了一种基于二阶滑模与MRAS相结合的转速辨识方案。该方案首先通过二阶Super-Twisting滑模观测器对一个中间变量进行观测,且该观测器无需转速信息,将其作为MRAS速度观测器的参考模型。而MRAS观测器的可调模型则由磁链的电流模型改造而来。据此,利用Popov超稳定理论设计了转速自适应率,用以调节可调模型,并获得转速信息。此外,本文在实现转速辨识的基础上,设计了基于二阶Super-Twisting滑模观测器的转子磁链观测方案,以较为准确地获取转子磁链,进而实现直接磁场定向。最后,搭建了5.51kW异步电机矢量控制系统的MATLAB仿真模型和实验平台,对所设计的转速辨识及转子磁链观测方案进行了仿真和实验研究。结果证明了该方案的可行性和有效性。
[Abstract]:With the rapid development of social economy, energy shortage and environmental pollution are increasingly prominent. In recent years, electric vehicles as a clean and efficient means of transportation have been paid more and more attention. The performance of electric vehicle mainly depends on the performance of its driving motor, which promotes the further development and improvement of motor control technology. With the development of vector control technology and the advantages of low cost, maintenance-free and wide speed range of asynchronous motor, asynchronous drive system has been widely used in electric vehicles. In electric vehicle, the installation of speed sensor not only increases the cost of system control, but also affects the reliability of speed signal detection due to the bad environment of vibration and electromagnetic interference. Therefore, speed sensorless vector control technology has become an essential technology for high performance motor drive system, and the core of its technology is speed and flux observation. At the same time, the accurate observation of flux is of decisive significance to the performance of vector control. In this paper, the speed sensorless vector control technology of induction motor based on rotor flux orientation is studied, and the two core contents of speed and rotor flux observation are deeply studied and analyzed. Based on the mathematical model of induction motor, two typical vector control schemes, indirect magnetic field orientation and direct magnetic field orientation, are discussed briefly. Secondly, aiming at the problems of the traditional model reference adaptive system (MRAS) speed identification method, a speed identification scheme based on the combination of second-order sliding mode and MRAS is studied. First, a second order Super-Twisting sliding mode observer is used to observe an intermediate variable, and the observer is used as the reference model of the MRAS speed observer without speed information. The adjustable model of the MRAS observer is modified by the current model of the flux chain. Based on this, the speed adaptive rate is designed by using the Popov hyperstability theory to adjust the adjustable model, and the rotational speed information is obtained. In addition, on the basis of speed identification, a rotor flux observation scheme based on second-order Super-Twisting sliding mode observer is designed to obtain rotor flux accurately and realize direct flux orientation. Finally, the MATLAB simulation model and experimental platform of 5.51kW asynchronous motor vector control system are built, and the speed identification and rotor flux observation scheme are simulated and experimentally studied. The results show that the scheme is feasible and effective.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM343

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