Coupled Electromagnetic/Thermal Analysis And Optimization Method Research On Doubly Salient Machine

For Doubly Salient Electromagnetic Machine(DSEM),the rotor structure is simple and solid and magnetic field is easy to adjust,which has attracted many scholars in many areas.Electrical machine is an electromechanical energy conversion device that interacts with many physical fields,such as electromagnetic field,fluid field,stress field and temperature field.In order to ensure the normal and stable operation of the machine,the machine designer must be able to fully consider the interaction between these various fields in the motor design phase,making the multi-physical fields achieve a relative stable state.In this paper,finite element software is used as a tool to analyze the basic operating principle and electromagnetic characteristics of the DSEM with the field-circuit coupling model.Aiming at the Double Salient Electromagnetic Generator(DSEG)of 18/12 configuration,short circuit characteristic,external characteristic and power output characteristic under DSG2 power generating mode are analyzed.The influence of electromagnetic parameters such as motor speed and excitation current on these characteristics are analyzed.Considering the heating condition of machine,the copper loss and iron loss are discussed in detail.The changes of these losses under different rotational speed,different load and different field current are also tested respectively.The three-dimensional temperature field model of the DSEM is established,and the specific calculation method is given for all of the heat-related coefficients.The convection heat dissipation of the air gap is processed by a simplified way.The governing law of the constant voltage regulation of the generator is obtained based on the finite element method.The relationship between the corresponding excitation current and the armature current can be fitted by the cubic function.In order to ascertain the generator's ultimate capacity,thermal performance is analyzed through coupled EM/thermal model.The influence of various losses on the temperature field of the generator is studied and the sensitivity of some thermal parameters of the DSEM has been investigated.Experiment bed has been established to test the generating performance and thermal performance.The simulation results are compared with the experimental results,which verify the validity of FEA and the coupling analysis of thermal field and electromagnetic field.