异步电机自适应磁链观测器分析设计(论文12000字)
摘要
随着矢量控制技术的发展，异步电机的控制性能在不断提高，广泛应用于航空航天和交通运输领域。实现矢量控制的关键是准确估计电机磁链，计算出正确的磁场定向角，实现坐标系沿磁场定向，定向后的方程能对磁链和转矩解耦控制。观测磁链的同时，可以实现对电机转子转速的估计，因此能够去除速度传感器结构，降低异步电机控制系统成本和提高系统对复杂工况的适应性。因此对磁链观测器展开研究，提高磁链和转速估计的性能，对改善异步电机控制性能具有很大的意义。
在异步电机三相模型的基础上，引入坐标变换得出两相静止和旋转模型，作为整个研究和仿真系统建立的基础。针对电压模型的纯积分问题，提出了使用一阶低通滤波器带替纯积分器并进行补偿的方案，提高了磁链计算的准确性，使用改进电压模型作为参考模型，有助于提高转速估算性能。本文构造了异步电机降阶观测器，降低了电机控制系统的阶数，对反馈增益矩阵和转速自适应律进行了设计，克服了传统电压和电流模型的缺点，提高了磁链观测和转速估计性能。最后使用一阶前向欧拉法对观测器模型离散化，在simulink中实现离散系统的仿真，仿真结果验证了本文所设计磁链观测器的可行性。
关键词：降阶磁链观测器 无速度传感器控制 反馈矩阵 转速自适应律
Analysis and design of adaptive flux observer for asynchronous motor
Abstract
With the development of vector control technology, the control performance of asynchronous motor is improving, which is widely used in aerospace and transportation fields. The key to realize vector control is to accurately estimate the motor flux, calculate the correct magnetic field orientation Angle, and realize the coordinate system along the magnetic field orientation. At the same time of observing the flux, the rotor speed of the motor can be estimated. Therefore, the structure of the speed sensor can be removed, the cost of the control system of the asynchronous motor can be reduced and the adaptability of the system to complex working conditions can be improved. Therefore, it is of great significance to study the flux observer and improve the performance of flux and speed estimation.
Based on the three-phase model of asynchronous motor, two phase static and rotation models are obtained by introducing coordinate transformation, which is the foundation of the whole research and simulation system. In order to solve the problem of pure integrator in voltage model, a scheme of replacing the pure integrator with a band of first-order low-pass filter and compensating is put forward, which improves the accuracy of flux calculation, and the improved voltage model is used as a reference model, which is helpful to improve the speed estimation performance. In this paper, the order reduction observer of asynchronous motor is constructed, the order of motor control system is reduced, the feedback gain matrix and the speed adaptive law are designed, the shortcomings of traditional voltage and current models are overcome, and the performance of flux observation and speed estimation is improved. Finally, the first-order euler forward method is used to discretize the observer model, and the simulation of the discrete system is realized in Simulink.The simulation results verify the feasibility of the flux observer designed in this paper.
Keyqords: reduced order flux observer; speed sensorless control;feedback matrix; speed adaptive law;
目 录
摘要 ……………………………………………………………………………………………Ⅰ
ABSTRACT …………………………………………………………………………………Ⅱ
第一章 绪论……………………………………………………………………………………1
1.1课题背景及研究意义 ……………………………………………………………………1
1.2 磁链观测器研究现状……………………………………………………………………1
1.3 本文主要内容及安排……………………………………………………………………2
第二章 异步电机数学模型和矢量控制基本原理 ……………………………………4
2.1 异步电机数学模型 ……………………………………………………………………4
2.1.1三相静止坐标系下异步电机数学模型……………………………………………4
2.1.2 坐标变换和矢量变换 ……………………………………………………………6
2.1.3两相静止坐标系下异步电机数学模型……………………………………………8
2.1.4 两相同步旋转坐标系下的异步电机数学模型……………………………………9
2.2 矢量控制 ………………………………………………………………………………10
2.2.1 矢量控制基本思想 ………………………………………………………………19
2.2.2 矢量控制的实现 …………………………………………………………………10
2.3 本章小结 ………………………………………………………………………………11
第三章 传统磁链观和转速估计测方案 ………………………………………………12
3.1 传统开环观测器 ………………………………………………………………………13
3.1.1 电压模型法 ………………………………………………………………………13
3.1.2 电流模型法 ………………………………………………………………………13
3.2 改进型电压模型法 ……………………………………………………………………14
3.2.1 积分器问题分析 …………………………………………………………………14
3.2.2 改进电压模型 ……………………………………………………………………15
3.3 模型参考自适应转速辨识 ……………………………………………………………16
3.4 本章小结 ………………………………………………………………………………17
第四章 降阶磁链观测器设计 ……………………………………………………………18
4.1 降阶磁链观测器概述 …………………………………………………………………18
4.2 反馈矩阵设计 …………………………………………………………………………19
4.3 转速自适应律设计 ……………………………………………………………………19
4.4 仿真平台 ………………………………………………………………………………21
4.5 仿真结果 ………………………………………………………………………………22
4.6 本章小结 ………………………………………………………………………………26
结语 ……………………………………………………………………………………………27
参考文献 ………………………………………………………………………………………28
致谢 ……………………………………………………………………………………………30 |
