Analytical Calculation of the Equivalent Circuit Parameters of Non-Salient Pole ‎Large Synchronous Generators

Optimal Design of electrical machines using population-based optimization algorithms needs computationally fast model for evaluating the performance characteristics from design data, i.e. geometric dimensions, winding layouts, material properties. The Electric Equivalent Circuit (EEC) is a simple and appropriate model with acceptable accuracy to be incorporated in the design procedure. In this paper, an analytical approach is presented for calculating the EEC parameters of large non-salient pole synchronous generator based on winding-function method. Although the synchronous generator is well recognized, calculation of its dynamic EEC parameters is not reported in previous studies. Special issues of high-rated industrial synchronous generators are considered such as rotor slots with different dimensions, rotor sub-slots, the damper winding which is created from rotor wedges and retaining rings, saturation of magnetic flux routes in d-q-axis and stator core stacking. The connections of damper windings in d-q-axis and definitions of turn-ratios to refer the parameters to the stator-winding side are of novelties of the research. The calculated parameters for a 200MVA power-plant generator are compared with the experimentally obtained parameters. The results of EEC analysis of the studied machine have acceptable coincidence with the experimental and 2D finite-element simulation results, which proves the validity of the proposed method.