Research Of Electromagnetic Design And Technics Of Double-winding Pole-switching Double-cage Induction Motor Using In Mine

As the driver of coal conveyor, 3-phase double-winding pole-switching doublecage induction motor works in high temperature, muggy, explosive environment for long time. The phenomenon of coal accumulation on the conveyor in the work usually breaks the motor. Therefore, higher standard for electromagnetic performance and structural feature is required on this type of motor. Both the electromagnetic design and the technological requirements are needed to consider more questions in detail. This thesis focuses on the research of the electromagnetic design and the manufacture of this motor.Firstly, based on the applying background and operating requirement of the motor,the structure, the main dimension and the main parameters are designed and chosen for a prototype. Secondly, according to the electromagnetic design characteristics of the motor, the calculating method of stator slot leakage reactance is researched, and an electromagnetic design program is developed on the platform of Visual Basic 6.0. The results of the electromagnetic design and the third-party design with the prototype’s experiment data are compared. Thirdly, finite element model of the prototype is established and the starting current, the starting torque and the maximum torque of the prototype are then calculated. The results show that the accuracy of finite element method is much better than that of the electromagnetic design. Furthermore, the leakage reactance and skin effect coefficient of double-cage rotor slot are calculated by finite element method. And then, the skin effect coefficient curve is fitted into the electromagnetic design program. Fourthly, the special process in the prototype assembly are summarized, the rust-proof process of explosion-proof surface and the insulation dip coating process of stator winding are researched. Fifthly, the magnetization curve and the loss curve of the silicon steel sheet are measured, and the tested data are fitted into the electromagnetic design program. Therefore, the accuracy and practicability of the electromagnetic design program are improved. Finally, the better prototype design is optimized by using the revised electromagnetic design program.The results show that the function of electromagnetic design procedure is powerful and useable, and the calculating results are basically correct. The calculating accuracies of finite element method on electromagnetic performance, rotor slot leakage reactance and skin effect are much better than those of electromagnetic design program. Summedthe special process and researched the process test ensure that the prototype is qualified and working-reliable. It has guiding significance for the actual production of the prototype.