Analysis And Optimization Of Can Energy Consumption For Liquid Immersed Motor

The liquid immersion motor is the core transmission element of the hydraulic pump system,which is characterized by a shielded structure can ensure that enables stable operation under complicated working conditions.However,the addition of stator and rotor cans will generate additional eddy current losses,reduce the operating efficiency of the shielded motor and inhibit the increase in power density.To deeply analyze the electromagnetic coupling relationship in canned motors,this thesis takes a 15 kW liquid immersion induction motor as the research object to study the core problem of eddy current loss in cans.The specific research content is as follows:Taking the induction motor as a prototype,the appropriate slot pole fit and applicable slot type are selected according to the characteristics of the liquid immersion motor,and the appropriate material is selected according to the characteristics of the shield sleeve.Then,the electromagnetic parameters of the liquid immersion motor are obtained.The electromagnetic coupling analysis method is used to analyze the generation and distribution of magnetomotive force.According to the model of the winding,magnetic field and the actual characteristics of the liquid immersion induction motor,the magnetic field is modeled by using the two-dimensional multilayer electromagnetic field theory,which takes the effects of salient pole effects,magnetic saturation,axially induced end effects,and can effects into account.An analytical formula for the characteristic quantities related to the motor performance is provided,which provides a faster method for calculating the can loss of a liquid immersion motor.The models of ordinary induction motors and liquid immersion induction motors are established by using finite element software.By comparing with ordinary the eddy current losses on the cans are studied.In the finite element 3D environment,the eddy current distribution on the stator can and rotor can are further analyzed.Considering the end effect,the causes and distribution characteristics of the eddy currents on the cans are analyzed.The thesis compares the change of eddy current on the rotor can at starting time and after rated steady state operation.The modeling process is used to summarize the algorithm flow of the main electromagnetic analysis program.The radial component of the shield magnetic flux density and the can loss obtained by the electromagnetic coupling analysis method are compared with the finite element method.The change of the total loss of the motor with the load coefficient is obtained by comparison experiments to verify the accuracy of the proposed scheme.The algorithm can evaluate the electromagnetic field quickly and accurately and calculate the motor losses accurately.The work done in this thesis can provide the necessary theoretical basis for the design and optimization of shielded motors.