感应电机直接转矩模糊控制技术研究

【作者】 曹开玉；

【导师】 徐中； 关慧贞；

【作者基本信息】 大连理工大学 ， 机械电子工程， 2004， 硕士

【摘要】 随着电力电子技术和计算机技术的飞速发展，交流电气传动正在逐步替代传统的直流电气传动系统。交流异步电机(感应电机)控制方式有多种，其中直接转矩控制是目前较为先进的一种。它省掉了许多坐标旋转变换及复杂的运算，其控制思想新颖、控制结构简单、控制手段直接。模糊控制具有较强的鲁棒性，是直接转矩控制较好的实现手段。 本文通过电机反馈的电流和电压来直接计算转矩、磁通，通过模糊处理来实现对逆变器开关状态的选择，从而实现了对电机的直接转矩控制；采用模糊神经网络对定子电阻进行离线训练与在线检测，有效地改善了DTC系统的低速时，电机定子电阻的变化对系统的影响，同时采用PI对系统的速度进行控制，使得电机速度超调量小，脉动小，过渡平稳。 由实验结果看，定子电阻辨识的偏差在±3％以内，达到工业控制要求的5％。并据仿真结果看，此控制方式可使转矩在0.3μs内快速响应，且磁链轨迹接近圆形，电流及磁链波动都较小。因而此种控制方式具有转矩响应迅速，是一种具有高静、动态性能的交流调速方法，具有较好的发展前景。更多还原

【Abstract】 With the rapid development of the power and electric system and computer technology, AC drivers are replacing the conventional DC drivers. The control method of AC motor (Induction Motor) is very excessive, Comparatively, DTC is much more advanced. In DTC, the mathematic model of AC induction motor is analyzed in the stator coordinate and the flux and torque are controlled directly. Therefore, much coordinate rotate transformation and complicated computation are saved and the control method is novel, simple and direct. Fuzzy control is robust, and it is a better way to realize direct toque control.In this thesis, the feedback current and voltage of the motor are made use to compute the torque and flux directly, and use fuzzy control method to select the state of the inverter. The DTC of motor is realized; the stator is trained off-line and detected on-line by FNNS (fuzzy neural network system), so in DTC low speed performance is effectively improved; at the same time PI is used to control the speed, the low speed exceedance and transition placidity are attained.From the result of the experiment, the observed error of the stator resistance is less than ?% , that can satisfy the industry control, and from the result of the simulation, the torque can reach the given demandiin 0.3μs, the flux trace is close to a circle. The fluctuation of current and flux is small. So, compared with the previous control method, the method in this paper has many advantages, such as quick torque response, high dynamic and static performance. Therefore, this method is promising.更多还原