Design And Optimization Of Doubly Salient Electro-magnetic Motor

The drive system of electric forklift is the core technology of transition from traditional internal combustion forklift to electric forklift. Simple configuration, flexible control, high power density and efficiency, and acceptable cost are the basic requirement for the onboard generator system. The design and optimization of the doubly salient motor for electric forklift drive system is investigated in this paper.Development trend of electric forklift and the advantages and disadvantages of the motors used in the forklift truck and electric vehicles are systematically summarized. The state of art of the new variable reluctance machines is given. It indicates that the doubly salient electro-magnetic machine employed in electric forklift truck drive system is a promising scheme.This paper introduces the basic structure, operation principle and mathematical model first. The principle of generating operation and motoring operation is introduced. The characteristics of DSEM, respectively under the control strategy of SAC, AAC and TPSS are analyzed in the dissertation. The influence on its output torque, torque ripple and efficiency when working under different control modes are analyzed. A 1.3k W DSEM is designed, the characteristics are obtained by 2D-FEA analysis. The optimal control parameters are given for four typical working conditions. A prototype machine is developed. The measurements of generating operation and motoring operation of the prototype machine are finishied. The experimental results verify the theoretical analysis and the finite element method.The influences of different parameters such as the air gap length, the stator pole height, the shape of the sator poles and the rotor pole arc are studied on the DSEM at both generating operation and motoring operation are investigated, which provide a reference for the optimization design of the motor. The principle prototype optimized developed andconducted experiments that show the correctness of the analysis. A prototype machine of the optimized DSEM is developed. The experimental results verify the theoretical analysis..