Electromagnetic and temperature field analyses of winding short-circuits in DFIGs

Abstract

The doubly fed induction generator (DFIG) plays an important role in the wind power generation. With the ever-increasing demand for improving the reliability and energy efficiency whilst reducing the maintenance and operational costs, there is a trend to develop the state-of-the-art condition monitoring technologies in wind applications especially for offshore applications. Winding short-circuits faults are among major electrical failures in DFIGs and can be caused by many reasons and can lead to undesirable heating to impact on the performance of the machine. They have not been fully understood due to the complexity of the problem which requires 3D electromagnetic and thermal fields to understand the fault mechanisms. This paper presents coupled electromagnetic and thermal field analyses of DFIGs with a focus on winding faults. Finite element tools are used for analyzing the characteristics of magnetic field, temperature distribution and heat flow during the healthy and faulty operations. This work can provide an insight into the DFIG's stator and rotor winding faults and suggestions for improvement in thermal design of the DFIG machines.