电动汽车异步电机直接转矩控制算法的优化研究

发布时间：2018-12-12 20:54

【摘要】：电动汽车作为新能源汽车种类中发展迅猛的品类之一，其对电机的控制效果要求也越来越高，对可靠性、效率、用户体验等方面也提出更为严格的要求，基于上述方面的需求，本文对异步电机的直接转矩控制系统进行了研究，主要完成以下工作：首先，分析异步电机的工作原理，对异步电机进行数学的系统建模，根据电动汽车对转矩响应速度更为严格的要求，以及为改善驾驶者行车体验，选择直接转矩控制作为本文的主要研究方向，进而提出三种感应电机的直接转矩控制改善方案，分别为传统DTC扇区提升优化、基于PI控制器的DTC优化、预测型DTC。其次，为能对整体控制达到更好的效果，定子磁链的准确性就变得尤为突出，本文研究了多种定子磁链观测技术，针对不同的环境要求下，选择合适的定子磁链观测方法。其中运用全阶磁链观测器技术不仅能完成闭环的定子磁链观测，也为后文的无速度传感器的设计提供方便。再次，由于工程实际成本可控制要求，需要对本系统运用无速度传感器的设计，本文提出一种简单的速度估算和以MRAS为核心的速度辨识技术。两者在不同条件下各有优势。为能进一步的提升系统效率，提出一种通过改变定子幅值的方式来减小系统损耗。最后，以预测型DTC控制算法为基础，并增加全阶磁链观测器、无速度传感器、定子磁链幅值最优等方面的优化，最终使DTC算法更为完善。本文利用Matlab/simulink平台对以上研究进行仿真研究及论证，仿真表明，，对直接转矩控制的优化效果明显，性能得到有效提升，速度辨识效果良好。将各个系统进行整合后，表现出了各模块的优化效果。
[Abstract]:As one of the rapidly developing categories of new energy vehicles, electric vehicles have higher and higher requirements for the control effect of motors, and more stringent requirements for reliability, efficiency, user experience, etc., based on the above requirements. In this paper, the direct torque control system of asynchronous motor is studied. The main work is as follows: firstly, the working principle of asynchronous motor is analyzed, and the mathematical model of asynchronous motor is established. According to the more strict requirement of torque response speed of electric vehicle, and in order to improve the driver's driving experience, direct torque control is chosen as the main research direction of this paper, and then three kinds of direct torque control improvement schemes of induction motor are put forward. Traditional DTC sector lifting optimization, DTC optimization based on PI controller, predictive DTC. Secondly, in order to achieve a better effect on the overall control, the accuracy of stator flux becomes particularly prominent. In this paper, a variety of stator flux observation techniques are studied, and appropriate stator flux observation methods are selected according to different environmental requirements. The full order flux observer can not only complete the stator flux observation of the closed loop, but also provide convenience for the speed sensorless design. Thirdly, because the engineering cost can be controlled, the speed sensorless design of the system is needed. This paper presents a simple speed estimation and speed identification technology with MRAS as the core. The two have their own advantages under different conditions. In order to further improve the system efficiency, a way to reduce the system loss by changing the stator amplitude is proposed. Finally, based on the predictive DTC control algorithm and the addition of full-order flux observer, sensorless speed sensor and the optimal amplitude of stator flux chain, the DTC algorithm is improved. In this paper, the Matlab/simulink platform is used to simulate and prove the above research. The simulation results show that the optimization effect of direct torque control is obvious, the performance is improved effectively, and the speed identification effect is good. After the integration of each system, the optimization effect of each module is shown.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U469.72;TM343

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