Investigation Of Wound-Rotor Brushless Doubly-Fed Frequency Control System

The Brushless Doubly-Fed Machine (BDFM) shows great success as a variable speed constant frequency generation, and it also shows commercial promise as a variable speed drive. However, for this promise to be realized the design of the machine must be improved beyond that proposed to date. This dissertation contributes towards this goal through application discusses in frequency control system and performance research.The Brushless Doubly-Fed Machine (BDFM) is a novel AC induction machine. The BDFM can achieve multiple operation mode, such as asynchronous, synchronous and doubly-fed operation mode. It will have wide application in the control-frequency saving-energy adjustable speed drive (ASD) systems, such as fan and pump load drives, The BDFM avoids the use of brush and slip ring and has some advantages, such as simple structure, robustness, reliability, adjustable power factor and a fractional rated converter. This study about a wound rotor BDFM with its special rotor structure, it is more flexible in design, therefore become a new hotspot in variable frequency system.Based on existing literature, the study reviews the BDFM the development process in recent years, focusing on changes in the structure of the motor, highlights the advantages of wound rotor structure. It also illustrates the working principle of the motor with several mathematical models of the motor equations, such as abc model and dq model. Summing up the above analysis, this paper presents a calculation of wound rotor BDFM steady state mathematical model.In this paper, the simulation models of all compositions of the frequency control system are built up with the software and simulation experiments are done. By comparing the simulation results and the experimental data, it shows the reasonable of the simulation model and the frequency control system has good performance.