负载换流逆变器驱动电励磁同步电机无速度传感器模型预测控制方法

Speed Sensorless Model Predictive Control for Load Commutated Inverter-Fed Electrically Excited Synchronous Motor

负载换流逆变器(LCI)驱动电励磁同步电机控制系统广泛应用于中高压场合,在应对干扰和负载变化上,较大的系统惯性系数和较低的开关频率导致其动态响应性能欠佳。该文提出一种基于LCI驱动电励磁同步电机的无速度传感器模型预测控制方法。首先根据LCI的数学模型建立预测状态方程,同时给出合适的代价函数和约束条件;然后分析负载换相模式下的控制矢量模型,给出速度观测器的设计方法和参数选择依据,并针对负载变化对速度观测产生的影响进行分析和补偿。同时该观测器还能够同时实现逆变桥输入电压和端电压相位的观测;最后,通过3.75kW的LCI驱动电励磁同步电机实验平台对提出的无速度传感器模型预测控制方法进行实验验证。结果表明所提出的控制方法能够有效提升系统的动态响应性能,所设计的观测器具有可行性,速度观测结果在额定阶跃负载下误差小于13°。

Load commutated inverter(LCI)-fed electrically excited synchronous motor control system is widely used in medium and high voltage industrial applications.In response to disturbances and load change,the system dynamic response performance is poor due to its large inertia coefficient and low switching frequency.A speed sensorless model predictive control method based on LCI-fed electrically excited synchronous motor is proposed in this paper.Firstly,the prediction equation of state is established according to the LCI model,and the appropriate cost function and constraint conditions are given.Then,the control vector model in load commutation mode is analyzed.The design method and parameter selection principle of designed speed observer are given,and the effect of load change on speed observation is analyzed and compensated.At the same time,the designed observer can observe the inverter input voltage and terminal voltage phase.Finally,the proposed speed sensorless model predictive control method is verified at a 3.75kW LCI-fed electrically excited synchronous motor experimental platform.The results show that the proposed control method can effectively improve the dynamic response performance of system,and the designed observer is feasible.The speed observation error is less than 13°with rated step load.