Sensorless Control of Ship Shaft Stand-Alone BDFIGs Based on Reactive-Power MRAS Observer

Abstract

This article proposes a rotor position observer based on a reactive power model reference adaptive system (MRAS) for sensorless direct voltage control (DVC) strategy of the stand-alone brushless doubly fed induction generators (BDFIGs). The proposed MRAS observer is based on the control winding (CW) reactive power and the power winding (PW) field orientation. The suggested new sensorless control method does not require flux computation, which can ensure the simplicity and efficacy of the proposed method. The stability analysis of the new observer is investigated and confirmed with the concept of hyperstability and using Popov's criterion methodology. The robustness of the new control method is analyzed under parameter uncertainties. Furthermore, comprehensive simulation and experimental results are obtained with a prototype wound-rotor BDFIG. The corresponding results confirm the capability and effectiveness of the proposed sensorless DVC strategy with a good transient behavior under different operating conditions for the stand-alone BDFIG system. Moreover, these results assure that the presented rotor position observer is robust via any machine parameter change.