Optimal Design And Control Study Of The Marine Shaft Brushless Doubly-fed Generator

Shipping industry downturn,improving environmental awareness and high costs make shipping companies pay attention to energy conservation.Shaft generator using the surplus capacity of the main engine improves the efficiency of ship power station,but it's expensive,unreliable,slow and needs a large capacity inverter.Brushless doubly-fed motor(BDFM)uses a special rotor and a small capacity inverter to realize constant-frequency and constant-voltage power output in a wide speed range.BDFM has high reliability and costs little which makes it a promising future.This paper introduces the development of shaft generator and BDFM and the research status at home and abroad which show the advantages of BDFM used as shaft generator.It analyses the operation principle and the magnetic field modulation theory and introduces the structure characteristics of BDFM whose stator has two sets of winding including power winding and control winding and whose rotor can be a nested cage rotor,salient pole reluctance rotor,radial laminated reluctance rotor or wound rotor.BDFM can run at asynchronous,synchronous,doubly-fed speed regulation and power generation operation mode.Then it introduces the size design and calculation of BDFM and radial laminated reluctance rotor is selected as research subject.Ansoft Maxwell software is used to analyze the rotor structure parameters of BDFM to obtain the best ones,including pole arc factor,magnetic layer number,layer width and distance from layer to axis of the rotor and inductance parameters is calculated.It introduces the mathematical model of BDFM and uses Matlab/simulink software to build the marine shaft BDFG scalar control strategy model to simulate and study the running performance of it.