Analytical Model of Doubly-fed Induction Generator-motors for Full-region Operation Analysis

The accurate modeling of large-scale doubly-fed induction generator-motors (DFIGMs) is crucial to support the development of variable-speed DFIGMs in pumped-storage plants. In this paper, a novel analytical model of DFIGMs is proposed, which takes into account both spatial- and time-harmonics using the spiral vector method and an improved permeance model. Additionally, the model considers the influences of full-region operation and pulse-width modulation (PWM) in the rotor converter. The distributions of magnetic field, electromotive force (EMF), and torque performance under various operating conditions are further analyzed by the model. To validate the proposed model, comparisons are made with finite-element simulations and experimental results obtained from a 3MW DFIGM prototype, confirming its accuracy and reliability. This analytical model serves as a crucial foundation for advancing variable-speed DFIGMs technology in pumped-storage plants.