Research On Starting Process Of Solid-Rotor Synchronous Motor

Since solid alloy is adopted as the rotor material in solid-rotor synchronous motor, the motor has a good starting performance. In some areas, only this kind of motor can be adopted, and can be applied broadly in many fields. During the starting process of this motor, eddy current and over-heating phenomenon are obvious on the rotor parts. To describe the starting process of the motor truly, a coupled analysis of several fields, including electromagnetic field, temperature field and certain other physical fields, is very necessary.In this thesis, firstly the solved region, boundary condition and assumption condition of the solid-rotor synchronous motor are given. In virtue of electromagnetic field theory and variational method, the 2-D mathematical model of solid-rotor motor during the starting process is built up. The discretization pattern, element analysis and total composing of eddy-current field equations are given. On the base of field-circuit-motion coupling, with editing external circuit of windings and using Ansoft software, auto-excitation is realized. On noload condition, the magnetic flux density distribution at different time is provided. The current distribution in the rotor surface and performance curves of the motor are obtained. The starting current, torque and dragging torque are calculated. All these phenomena show that the solid-rotor motor has a good starting performance. Through comparing different conductivities and permeabilities of rotor material respectively, some influence is studied on the starting performance. The computation results and analysis will be useful for selecting copper-iron alloy.According to heat transfer law, on the base of 3-D static temperature field dispersion style, 3-D mathematical model of motor's static temperature field is founded. From the eddy current-temperature field coupling, temperature field of the motor during the starting process is presented.