Design And Research On Characteristic About High-speed Doubly Salient Electro-magnetic Machine Used As Compressed Air Energy Storage

The Doubly Salient Motor(DSM)has the advantages of simple structure,strong reliability,high power density and high temperature resistance,so it is suitable for high speed applications.However,the structure of DSM is the salient pole and slot,the magnetic field distribution of DSM is serious nonlinear,which brings many difficulties into the analysis.Moreover,iron loss and mechanical Strength at high speed have influence on performance,which brings much problem on motor design.This paper is based on present achievements of DSM and develops a 20 kW 6/4-pole Doubly Salient Electro-Magnet(DSEM)aimed at compressed air energy storage system.First,the introduction and achievements of motor applied to compressed air energy storage system at home and abroad concerned DSM is given.Also,operating principle and mathematical model of DSEM is introduced respectively.Moreover,based on the linear disposal of excitation flux,some control strategies are put forward,such as the three-phase three-state(TPTS),three-phase six-state(TPSS)and so on,which is foundation for further research on DSEM.Taking material,structure and size into consideration,a 6/4-pole DSEM applied to compressed air energy storage system is designed.Then,the finite element method(FEM)is applied to analyze the magnetic field.And a series of static characteristics are investigated,such as air gap magnetic density,field flux,inductance and armature reaction.Also,a primary research work has been done on some steady characteristics of the motor,such as phase current,field flux.Different control strategies are compared and analyzed,which provide references for the application promotion of DSEM.By applying the research tools of FEM,the paper studies the influences to the static characteristics and steady characteristics of different aspects such as the arc of rotor pole,width of stator,gas length and axial length in detail.These provide references for the further design of motor.Finally,a 6/4-pole DSEM is achieved by analyzing unloading performance,torque-current characteristic,mechanical characteristic,mechanical Strength and efficiency.Moreover,temperature field is applied to analyze the designed motor,and all results show that the motor achieved expected effect.