A Novel Thermal Network Model Used for Temperature Calculation and Analysis on Brushless Doubly-Fed Generator with Winding Encapsulating Structure

In recent years, magnetic-barrier rotor has been put forward for brushless doubly-fed generator (BDFG) application owing to its desirable performance, such as high power density and strong magnetic coupling ability. However, it also causes significant losses induced by harmonics and high temperature problem. Hence, it is a major challenge to evaluate Bref-DFG temperature rise fast and accurately. So far, aiming at magnetic-barrier rotor, there has been no accurate thermal network model established achieving this goal. In addition, wingding end encapsulating technology has been used for a few years and its heat dissipation potential is determined by the materials. Therefore, the application of novel material in winding encapsulating structure is desirable to improve the heat dissipation potential. In this paper, an equivalent thermal network model, thermal resistance models of magnetic-barrier rotor, and a winding encapsulating structure with novel materials are further established for thermal analysis. Subsequently, temperature distributions for BDFG components are also calculated by finite element method, while the results are compared with those by analytical method. The BDFG prototype is manufactured with experimental tests performed. The correctness of the equivalent thermal network models proposed in this paper is verified by the test results.