Three-Phase Steady-State Model of Type-3 Wind Generation Unit—Part I: Mathematical Models

This paper develops a comprehensive mathematical steady-state fundamental-frequency model of the Type-3 wind driven unit, i.e., a doubly fed asynchronous generator (DFAG) and its associated converter system, for three-phase power-flow analysis. First, a novel steady-state, sequence frame-based model of the generic Type-3 unit, to represent 1) the control capabilities and 2) the operating limits of the rotor-side and the grid-side converters under balanced and unbalanced conditions, is developed. Then, new strategies to determine the reference set-points of the controllers for compliance with the operating limits, are also presented. The model, including the proposed strategies/algorithms, is incorporated in a three-phase, sequence frame-based, power-flow algorithm. Applications and validation of the developed model and the set-points update strategies, and evaluation of the computational efficiency of the power-flow algorithm will be presented in Part II of this paper.