Optimization-Based Position Sensorless Control for Induction Machines

A novel optimization-based sensorless technique for Induction Machines is presented in this work. The algorithm is able to estimate speed and position instantaneously (limited only by the Nyquist frequency and the PLL bandwidth) at standstill low and high-speed. A cost function is introduced based on the dynamic machine model. The stability analysis of speed and position estimation shows whether the system is convex by solving the Hessian matrix of the cost function. The method is unique for the entire speed range, in which high-frequency signal is injected to the machine terminals at low speeds, to increase the convex region of the cost function.