Research On Loss And Temperature Rise Of Switched Reluctance Motor For Crane

Lifting motors are widely used,it is often used in construction engineering,metallurgy and other industries,has made great contributions to national construction,switched reluctance motor has the advantages of simple structure and low cost,is very suitable for use as a lifting motor,however,due to the special structure of switched reluctance motors,so that the magnetic density of the motor presents a non-sinusoidal waveform,and magnetic saturation will occur in local areas,which are not mature enough,but also influenced by the motor control system,the change of magnetic field is also different under different rotating speeds and different loads,because of the complexity of magnetic field changes,the calculation of motor loss is also more complicated,the loss of the motor will generate heat again,the internal temperature of the motor is increased,thus affecting the service life of the motor,therefore,studying the magnetic field,loss and temperature rise of switched reluctance motor is of great value to the design and optimization of the motor.In this dissertation,a 5.5k W switched reluctance motor was taken as the research object,based on electromagnetic field theory,a two-dimensional transient electromagnetic field calculation model is established,the experimental platform of switched reluctance motor is established,the calculated current is compared with the experimental current,verify the correctness of the two-dimensional finite element method,verify the accuracy of the two-dimensional finite element model,in order to highlight its performance in the field of hoisting,two-dimensional finite element models of induction motor and switched reluctance motor are established,the model has the same power and the same core length,the locked-rotor torque and other performances of switched reluctance motor and induction motor are compared,in the finite element model calculation of switched reluctance motor prototype,with double closed-loop drive circuit as motor control system,through the calculation andanalysis of the motor stator,under the rated working condition,the magnetic density waveform of each part of the stator core,and the change law of magnetic density is analyzed and studied,the stator and rotor core losses and winding copper losses of the motor under rated working conditions are calculated,and a three-dimensional finite element thermal analysis model of the motor is established,the loss under no-load and rated load conditions calculated in the two-dimensional field is calculated,coupled as a heat source to a thermal analysis module of a three-dimensional field,the convection heat transfer coefficient of the motor at rated speed under downwind cooling is calculated,calculate and set parameters such as thermal conductivity,the temperature field distribution of the motor under rated load condition is obtained,the temperature rise in different parts of the motor is analyzed,finally,through the temperature rise experimental platform set up,the change data of temperature rise during no-load operation of the motor is measured,and compared with the calculated results.