A double concentric wound rotor brushless doubly fed generator

Abstract

The rotor structure is one of the key factors affecting the performance of the brushless doubly fed generator (BDFG). So far, three types of rotor structure have been developed, namely the reluctance rotor, the special cage rotor, and the double sine wound rotor. However, there still exist some problems, such as the high harmonic content of the rotor winding, resulting in large losses and low efficiency of the machine, and the complex winding design and manufacturing process. These problems restrict the industrial application of the BDFG. To solve these drawbacks, a double concentric wound rotor structure is proposed and presented in this paper for a 100‐kW BDFG. The proposed rotor structure can improve the conductor utilization ratios of the rotor winding and largely reduce the harmonic contents. The steady‐state performance of a 100‐kW prototype generator with the double concentric wound rotor structure is analyzed by finite element model simulation and experimental tests. The experimental results on the prototype show that the BDFG with the double concentric wound rotor structure gives good performance. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.