异步电机弱磁区转矩最大化策略

发布时间：2018-06-03 00:56

本文选题：异步电机 + 弱磁区　；参考：《吉林大学》2017年硕士论文

【摘要】：异步电机因其结构简单、控制方便及其鲁棒性,使其在电机驱动系统中占据重要的地位。异步电机一个非常重要的应用是在高速区,比如机床、主轴驱动和牵引驱动中,这就要求异步电机在整个运行区域内都能获得高转矩,实现高性能控制。电动汽车运行过程中频繁的启停、加减速等各种复杂工况的相互切换对异步电机的控制提出更高的要求,既要适应稳态运行,又要兼顾动态需求。本文针对异步电机弱磁区的控制进行了深入的分析和研究。本文首先讨论了异步电机矢量控制系统的基本原理。将三相A-B-C坐标系下具有非线性、多参量、强耦合、高阶时变微分方程的电机模型转化到两相d-q同步旋转坐标系下,完成对复杂数学方程的简化,实现磁链与转矩的解耦,方便系统的分析和控制。之后,本文讨论了异步电机运行过程中发生过压、过流、过载时的电压、电流限制方法,并根据电机运行约束条件将电机运行划分为三个区域,根据三个区域的不同特点,提出了能同时适应弱磁区稳态运行和瞬态波动,实现转矩最大化的控制策略。在弱磁区,充分利用电机和逆变器电压、电流容限,无需d轴电流控制器,通过控制定子电流转矩分量,稳定异步电机高速失步状态,实现稳态工作时转矩最大化。当电机工作在最大电压的动态需求时,根据速度波动的大小输出一个旋转角,旋转定子电压矢量,产生瞬态电压边缘,确保驱动系统的迅速响应。同时分析整个驱动系统的能量流动和损耗发生,考虑铁损对电机运行全区域的影响,尤其是在弱磁区,引入铁损补偿机制,提高系统的响应和转矩输出能力,从而提高电机的工作效率。最后,在MATLAB/Simulink环境下搭建仿真模型,并在LEVDEO电动汽车专用72V/5KW交流异步电机上测试。仿真和实验证明,该控制系统能实现异步电机弱磁区转矩最大化,能同时适应稳态运行和瞬态波动,具有很强的鲁棒性。
[Abstract]:Because of its simple structure, convenient control and robustness, asynchronous motor plays an important role in motor drive system. One of the most important applications of asynchronous motor is in the high speed area, such as machine tool, spindle drive and traction drive, which requires the induction motor to obtain high torque and achieve high performance control in the whole running area. The switching of complex working conditions such as frequent starting and stopping, acceleration and deceleration of electric vehicles puts forward higher requirements for the control of asynchronous motors, which should not only adapt to the steady operation, but also give consideration to the dynamic requirements. In this paper, the control of weak magnetic field of asynchronous motor is analyzed and studied. In this paper, the basic principle of vector control system for asynchronous motor is discussed. The motor model with nonlinear, multi-parameter, strong coupling and high-order time-varying differential equations in three-phase A-B-C coordinate system is transformed into a two-phase d-q synchronous rotating coordinate system to simplify the complex mathematical equations and decouple the flux and torque. Facilitate system analysis and control. After that, this paper discusses the methods of voltage and current limitation in the operation of asynchronous motor, and divides the motor operation into three regions according to the operating constraints, according to the different characteristics of the three regions. A control strategy for torque maximization is proposed, which can simultaneously adapt to steady state operation and transient ripple in weak magnetic field. In the weak magnetic field, the voltage and current tolerance of the motor and inverter are fully utilized, and the d axis current controller is not needed. By controlling the stator current torque component, the high speed out-of-step state of the asynchronous motor can be stabilized, and the torque maximization in steady operation can be realized. When the motor works in the dynamic demand of the maximum voltage, it outputs a rotation angle according to the magnitude of the velocity fluctuation, rotates the stator voltage vector, produces the transient voltage edge, and ensures the rapid response of the drive system. At the same time, the energy flow and loss of the whole drive system are analyzed, and the influence of iron loss on the whole running area of the motor is considered, especially in the weak magnetic field, the compensation mechanism of iron loss is introduced to improve the response and torque output ability of the system. So as to improve the working efficiency of the motor. Finally, the simulation model is built in MATLAB/Simulink environment, and tested on the special 72V/5KW AC asynchronous motor of LEVDEO electric vehicle. Simulation and experiments show that the control system can maximize the torque in the weak magnetic field of asynchronous motor and can adapt to steady state operation and transient fluctuation simultaneously, and has strong robustness.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM343

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