Abstract

The influence of the amplification factor in the flux state observer loop made according to the L-shaped equivalent circuit is considered for induction motor equipped with a squirrel-cage rotor. The state observer model is described by equations and by a block diagram. The calculation of the moment made by the state observer is based on estimating the stator flux in a fixed coordinate system. The effective voltage and the stator current were measured to determine the stator flux. The rotor flux and current were determined indirectly using these equations. The effect of the gain in the stator flux estimation loop is evaluated at different frequencies and moments, including the low frequency band and twice as high moment. This is the domain where the main problems of sensor-free control systems develop. The studies were carried out using the MATLAB/Simulink environment with the basic model of an induction motor having a squirrel-cage rotor. The analysis of the process revealed that modern systems of AC electric drives require developing systems having high accuracy in speed control without installing rotor position sensors. It is shown that this problem can be solved by using compensatory state observers, in which errors in estimating parameters of electromechanical converter can be corrected through mathematical operations through comparing the calculated (estimated) and actual alternating current parameters. It is found that the accuracy of the state observer performance gets better with an increase in the scaling compensation coefficient but the upper limit of this coefficient is limited by the noise level in variable measured.

中文翻译：

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感应电动机定子磁通状态观测器参数对保持电磁力矩精度的影响

摘要

对于装有鼠笼转子的感应电动机，考虑了根据L形等效电路制作的磁通状态观测器回路中放大系数的影响。状态观察器模型由方程和框图描述。状态观测器的力矩计算基于在固定坐标系中估计定子磁通。测量有效电压和定子电流以确定定子磁通。转子磁通和电流是使用这些方程间接确定的。定子磁通估计回路中增益的影响在不同的频率和时刻进行评估，包括低频带和两倍的高时刻。这是无传感器控制系统的主要问题所在的领域。这些研究是在 MATLAB/Simulink 环境中使用具有鼠笼转子的感应电机的基本模型进行的。过程分析表明，现代交流电驱动系统需要开发具有高精度速度控制的系统，而无需安装转子位置传感器。结果表明，该问题可以通过使用补偿状态观测器来解决，其中通过比较计算（估计）和实际交流电流参数，可以通过数学运算来纠正机电转换器参数估计中的误差。发现随着标度补偿系数的增加，状态观测器性能的精度提高，但该系数的上限受到测量变量噪声水平的限制。