An efficient sensor-less speed estimator, based on an adaptive non-linear high gain observer (HGO) which uses only the measured stator currents and control voltages in the presence of measurement noise, is proposed to estimate the speed of an induction motor. The proposed observer is an improved version of the common HGOs proposed in the literature. The observer gain, involving the use of a scalar time-varying design parameter governed by the Riccati differential equation, guarantees the best compromise between the fast convergence of the states and noise rejection with such adaptation of gains that the internal states of the observer exert low influence during the transient period and thus prevent system peaking. The design methodology of the proposed observer is given and its stability is studied. Results of simulation studies demonstrate that robustness and efficiency of the proposed observer are maintained under critical operating conditions, even where the efficiency of the fixed gain observer is decreased.

提出了一种基于自适应非线性高增益观测器（HGO）的高效无传感器速度估算器，该观测器在存在测量噪声的情况下仅使用所测量的定子电流和控制电压来估算感应电动机的速度。拟议的观察员是文献中提出的常见HGO的改进版本。观察者增益（包括使用由Riccati微分方程控制的标量时变设计参数）保证了状态的快速收敛和噪声抑制之间的最佳折衷，且增益的调整使得观察者的内部状态发挥了低在过渡期间产生影响，从而防止系统出现峰值。给出了拟议的观测器的设计方法，并研究了其稳定性。