Phase-Selection Control Rectifier Technology of Multi-phase Synchronous Generator for Wide Speed Range Operation

This paper proposes a phase-selection control rectification technology to regulate AC-DC rectifier voltage ratio and output a constant DC voltage for multi-phase synchronous wind generator operating in a wide speed range. A novel rectifying bridge topology consisting of six diodes and six thyristors is presented when taking a six-phase shift of 60°generator as an example. By selectively turning on and off the thyristors, four kinds of AC-DC rectifier voltage ratios can be obtained. On the one hand, four constant terminal voltages of six-phase generator are output by regulating the excitation with PID control at different wind speeds, on the other hand, the appropriate rectifier voltage ratio between AC side and DC side is realized by means of phase-selection control. Finally, the DC voltage could be maintained stably in a wide speed range. The simulation verified that the phase-selection control rectification technology can maintain the stability of the DC voltage when wind turbine operates in a wide speed range.