A Flux and Speed Observer for Induction Motors with Unknown Rotor Resistance and Load Torque and no Persistent Excitation Requirement

TL;DR

This paper introduces a novel flux and speed observer for induction motors that operates effectively with unknown rotor resistance and load torque, requiring only minimal measured signals and weaker excitation conditions.

Contribution

It presents the first global solution using DREMBAO for flux and speed estimation with relaxed excitation requirements in induction motors.

Findings

Achieves asymptotic convergence under weak excitation conditions

Provides exponential convergence when persistent excitation is assumed

Operates with only stator current and control voltage measurements

Abstract

In this paper we address the problems of flux and speed observer design for voltage-fed induction motors with unknown rotor resistance and load torque. The only measured signals are stator current and control voltage. Invoking the recently reported Dynamic Regressor Extension and Mixing-Based Adaptive Observer (DREMBAO) we provide the first global solution to this problem. The proposed DREMBAO achieve asymptotic convergence under an excitation condition that is strictly weaker than persistent excitation. If the latter condition is assumed the convergence is exponential.