Stator Inductance Tuning in MRAS Position Observer for the Model Predictive Control of Variable Speed Pumped Storage Unit

Doubly-fed variable speed pumped storage (VSPS) unit is a large capacity energy storage facility in the grid, contributing to the frequency stability of the grid. And its normal operation generally requires the accurate position information of the rotor. This paper presents a novel stator inductance tuning method to improve the precision of the position provided by the model reference adaptive system (MRAS) observer. The method improves the precision of the tuned mutual inductance value by identifying the stator leakage inductance coefficient. Besides, the method finalizes the mutual inductance faster than the traditional methods. In addition, a parameter sensitivity analysis formula is derived, which can quantitatively analyze the relationship between the mismatched inductance and the steady-state error of the observer. Finally, the effectiveness of the proposed method is fully validated by simulation results.