Rotor Optimal Design And Dynamic Performance Simulation Of Electrically Excited Brushless Synchronous Motor

Traditional motors mainly including squirrel cage induction motor, wound rotorinduction motor, permanent magnet synchronous motor, electrically excited synchronousmotor and special motor. Squirrel cage induction motor has a low power factor, woundrotor induction motor and electrically excited synchronous machine exist a problem thatbrush slip ring has poor reliability, there was a substantial rise in the cost of the permanentmagnet motor with rising price of rare-earth materials. Thus, there is an importantapplication prospect for developing a novel high performance AC motor with nobrush and excitation control.The electrically excited brushless synchronous motor researched in this thesis is a newtype synchronous motor, has significant difference in structure comparing with aconventional motor.This kind of motor can be self-starting and canceled brushes and sliprings, even maintenance free basically, and can work in the flammable and explosiveenvironment.Firstly, based on structure characteristics and operation principle of the electricallyexcited brushless synchronous motor, coupling ability as well as structure design ofcomposite rotor and radial laminated reluctance rotor had been researched, and compareinfluences of the two types’ rotor structure on the result of magnetic field modulation ofbrushless electrical excited synchronous motor, then structure design scheme with the bestcoupling character had been obtained.Secondly, parameters of electrically excited brushless synchronous motor with twodifferent rotors had been calculated, resistance value of power winding and excitedwinding had been obtained by circuit calculation; finite element calculation was conductedby using Ansoft, inductance parameter values of motor winding had been obtained bysimulation. The dynamic characteristics of the novel motor is analysed in detail, includingthe starting performance and pulling into synchronization characteristics. Under what circumstances pulling into synchronization can get the shortest time and the impact causedby the stator current minimum and sudden load performance is analyzed.Finally, a6+2pole electrically excited brushless synchronous motor had beendesigned, with power of20kw. Power winding of motor stator use double short-rangdistributed winding, exciting winding adopt single concentric winding, determine thecomposite rotor structure combined with magnetic barrier rotor and cage rotor. Meanwhile,each part loss of the motor had been calculated and analyzed, including stator iron loss,copper loss, rotor iron loss, copper loss and so on. On how to reduce loss and improve theefficiency of the motor to do some research, it provides a theoretical basis for future designof electrically excited brushless synchronous motor.