Design And Simulation Analysis Of Electrical Excitation Brushless Synchronous Generator

For the problems of low reliability of the current traditional electrical excitationsynchronous generator and high price of permanent magnet synchronous generator, a newtype of electrical excitation brushless synchronous generator is proposed in this thesis.Compared with the conventional electrical excitation synchronous generator, this kind ofgenerator not only has the advantages such as speed constant, adjustable power factor andhigh efficiency, but also has the characteristic of brushless slip ring structure, lowmaintenance costs and high reliability. Hybrid rotor structure which combines the structureof cage rotor and reluctance rotor is adopted in this kind of generator, which largely solvedthe problem of poor coupling capability between armature windings and field windings.Thus this type of generator is particularly suitable used as the wind power generationequipment which is not easy to maintain. The armature windings and the field windings areall embedded in the stator of new hybrid rotor electrical excitation brushless synchronousgenerator, while compared with conventional generators; the novelty of this type ofgenerator brings many key technologies to the electrical excitation brushless synchronousgenerator which to be solved.First, the preliminary program design of the electrical excitation brushlesssynchronous generator is given, including the determination of the stator structure, theselection of the rotor structure, the selection of the number of poles of the field windingsand the coordination of the poles of the two windings and so on. The influence of differentconditions on the electrical excitation brushless synchronous generator field modulationeffects is studied in-depth, the advantages and disadvantages of different designs arecompared and analyzed, the comparatively larger factors of the influence on generatorcoupling capability are summarized, and all above provides technical support forimproving the practical design of this kind of generator. Secondly, parameters and loss were calculated on this new type machine prototype.The resistance values were achieved via circuit calculation. The self-induction and mutualinduction were achieved via finite element simulation. Reference data was providedaccording to the calculation on the loss of the machine, such as the core loss, copper loss,mechanical loss and stray loss.Then, the simulation analysis of the steady-state and dynamic characteristics of theelectrical excitation brushless synchronous generator under different conditions are given,including no-load operation, load operation, three-phase short circuit, phase short circuit,single-phase ground short circuit and so on. By analyzing the air-gap magnetic, back EMFand the winding current, the dynamic characteristics curve of the generator under differentfault conditions are obtained.Finally, the final design of the prototype of the electrical excitation brushlesssynchronous generator is determined on the basis of the above work. The program of usingdouble short distribution armature windings and single concentric sinusoidal excitationwindings is proposed, while the hybrid rotor structure which combines the magnetic barrierand cage rotor type is used in the rotor. The prototype of the designed generator is beingdeveloped.