基于一阶线性自抗扰控制器的同步磁阻电机无速度传感器控制

Sensorless Control of Synchronous Reluctance Motor Based on First Order Linear Active Disturbance Rejection Controller

同步磁阻电机在实现无速度传感器控制时出现交叉耦合效应,导致dq轴电感随着电流发生非线性变化,转速环使用传统PI控制器已无法满足系统较强的抗扰性能和较高的转子位置估计精度。为了改善此问题,该文提出一阶线性自抗扰控制器的同步磁阻电机无速度传感器控制策略,利用其机械运动状态方程,将同步磁阻电机的交叉耦合效应及负载扰动变化视为扰动。首先通过扩张状态观测器对负载扰动快速观测并进行前馈补偿,以此来提高系统抗扰性;其次利用静止实验法,得到dq轴磁链与电流的非线性函数模型,将该模型运用至磁链观测器中,以减小交叉耦合效应,提高转子位置估计精度;最后在1.5 kW的同步磁阻电机对拖加载实验平台上进行实验,验证了该控制方案的有效性。

Synchronous Reluctance Motor(SynRM)is widely used in air compressors,fans,and electric vehicles because of its wide speed range,strong overload capacity,low cost,high reliability,and insensitive temperature rise during operation.To ensure the control accuracy of position and speed,installing a position sensor is necessary for position and speed measurement of the rotor,which makes the motor occupy a large volume,the cost is high,reliability is low,and immunity is weak.Therefore,taking the synchronous reluctance motor as the research object,this paper studies its speed sensorless control strategy to enhance system immunity.A speed sensor-free control strategy based on a magnetic chain observer is studied.However,the cross-coupling effect exists during the operation of SynRM,which causes the inductance to change nonlinearly with the current,reducing the accuracy of the rotor position estimated by the flux observer.Voltage with different amplitudes and frequencies is injected into the d-q axis by the static experiment.The forward Euler method is used to calculate the d-q axis magnetic chain.The linear least square method fits the non-linear function model of the d-q axis magnetic chain and current.Finally,the function model is applied to the magnetic chain observer to improve the rotor speed and position estimation accuracy.A speed sensorless controller strategy for SynRM based on auto-disturbance rejection technology is studied to overcome weak immunity and low robustness.Firstly,the design principle of the ADRC is analyzed,and an ADRC suitable for SynRM is selected.According to the SynRM mechanical motion state equation,load variation is regarded as a total disturbance,and the disturbance is quickly observed and compensated.In view of the disadvantage of extensive parameters and complex adjustment in ADRC,a linear function is used instead of the original nonlinear function,which improves the robustness of the system.Finally,a Matlab/Simulink simulation model of speed sensorless control strategy for the synchronous reluctance motor is built based on auto-disturbance rejection technology.The nonlinear function model of d-q axis flux and d-q axis current considering the cross-coupling effect is established and applied to the flux closed-loop observer method,improving the rotor position estimation accuracy.At the same time,a first-order linear active disturbance rejection controller is designed to improve the speed loop.The disturbance is compensated in time while observing the motor motion state,and the problems of overshoot,slow response speed,and slow speed recovery time when the motor is perturbed are solved.