Generalized High-Fidelity Reduced-Order Model of Doubly-Fed Machines and Induction Machines

Doubly-fed induction machines are widely used in wind power generation and high power drive applications. Brushless doubly-fed machines further improve the reliability and reduce the maintenance by eliminating brushes and slip rings, showing potential in replacing traditional slip-ring doubly-fed induction machines. High-fidelity plant models are critical for successful model-based control of electric machines. This paper introduces a generalized high-fidelity reduced-order model of doubly-fed machines applicable to doubly-fed induction machines, brushless doubly-fed machines, and singly-fed induction machines. The model accounts for saturation due to nonlinearity of magnetic materials and spatial harmonics due to winding layout and slot effects. The model supports system-level simulations and control development across various doubly-fed machine applications with high accuracy and fast solving speed. The paper demonstrates detailed modeling implementation and model performance using an exemplary slip-ring doubly-fed induction machine, and the model's efficacy is experimentally validated against a prototype brushless doubly-fed machine.