基于转速自适应全阶观测器的异步电机无速度传感器矢量控制算法,针对其低速发电状态下不稳定的问题,该文根据异步电机小信号线性化模型,推导出转速自适应观测系统的传递函数,并采用劳斯稳定性判据,提出一种基于全阶观测器的转速自适应观测方法。该方法通过在传统的自适应律中加入励磁电流观测误差项,使转速的观测精度得到大幅提高,并通过在线调节励磁电流观测误差项的比例系数,可使系统在低速发电状态下稳定运行。考虑到在运行过程中电机参数的变化,对此算法的参数鲁棒性进行了分析。通过7.5 kW异步电机能量互馈实验平台对此算法的有效性进行了验证。从实验结果可知,此新型速度自适应观测方法明显提高了低速下的速度观测精度,改善了系统的低速性能,并有效解决了低速发电状态下系统不稳定的问题。
In the speed-sensorless induction motor(IM) drive system adopting the adaptive full-order observer method,an unstable region encountered in the regenerating mode at low speeds is well known.To solve the problem,a novel speed estimation method is presented.Based on the small signal linearized model of IM,it deduced the transfer function of the speed adaptive estimation system and then developed a novel speed adaptive estimation method by applying Routh-Hurwitz criteria.The speed accuracy could be greatly improved by adding the magnetizing current error to the general speed estimation law,and the instability behavior in the low speed regenerating mode could be remedied by adjusting the adaptation gain on-line.Concerning the motor parameters variation during the operation,the robustness of the presented method was analyzed as well.The feasibility of the proposed scheme was verified by the experimental results of speed sensorless field-oriented vector controlled 7.5 kW induction motor platform.Experimental results show that the estimation accuracy of the speed and the low speed performance is greatly improved,and also a stable operation is acquired in a very wide speed range.