Transient finite-element analysis and testing of a salient-pole synchronous generator with different damper winding design solutions

Salient-pole synchronous generators are conventional electric machines which have been widely studied over decades. Nevertheless, some aspects still constitute a challenge for designers and need to be approached with state-of-the-art modeling and computation techniques. An example is illustrated in this paper dealing with a 14 MVA synchronous generator. Different design solutions for its damper cage are studied and implemented on full-scale machine prototypes. Transient finite-element analyses are used to predict the influence of damper design on machine sub-transient reactances. Comparisons are presented between experimental results and finite element simulations and a physical interpretation is provided of the relationship found between damper structure and machine sub-transient reactances.