Control Of Brushless Doubly-Fed Machines Based On Matrix Converter

The Brushless Doubly-Fed Machine (BDFM) is a single-frame, self-cascaded induction machine capable of operating in both the induction and the asynchronous mode. BDFM has the robust mechanical characteristics together with controllable speed and power factor,a relatively low rating power converter. These benefits attract more and more researcher's attention..In this paper, a comprehensive research on the BDFM with cage rotor is developed. After reviewing the progress of the BDFM, its structure characteristics and principals are discussed. The simulation model of the BDFM is established and behaviors under different operation modes are studied. The steady state equivalent circuits for the BDFM is detailed developed. After simplifying the steady state equivalent circuit, the power of the stator windings of the BDFM is explicitly expressed. So it is easy to know the power flow directions whether the BDFM works as a motor or as a generator.The paper mainly probes into the control strategy on the BDFM and presents Control strategy of Brushless Doubly-Fed Machines based on matrix converter. Matrix Converter is a novel AC-to-AC power converter device with bidirectional power flow, sinusoidal input/output current and unity input power factor, the lack of DC-link, the ability of four quadrant operation, the excellent waveforms of input current and output voltage, variable power factor input current. Because of such advantages, matrix converter will be choosed as control winding excitation source, Simulation results illustrate the good performance of stabilizing speed feedback and power factor can be fast adjusted.The research work has been supported by the important research projects funded by national natural science foundation. The project name is The Research of Distributed Wind-Solar Hybrid Generating System. Its number is 60534040.