Research On The Nonlinear Modeling Of Wound-Excited Doubly Salient Machine

Wound-Excited Doubly Salient Machine(WEDSM)is a new kind of reluctance motor with simple and reliable structure,high temperature resistance,small inertia,high reliability and flexible air gap flux regulation.This dissertation mainly researches on accurate nonlinear modeling of WEDSM.The motor and generator model of WEDSM are established by constructing the inductance model of each phase winding.What's more,the optimization of motor control strategies and power generator system are studied.In this dissertation,the requirement of the motor development in the modern aviation industry and the development of WEDSM are firstly introduced.Since WEDSM is one kind of reluctance motor,the researches of the reluctance motor like the Switched Reluctance Motor,especially it's modeling,are summarized in this dissertation.Then the dissertation summarizes the current research results of WEDSM modeling,analyzes the principle and characteristics of the existing modeling methods,and its technical detects and application limitations.Also,a WEDSM of 18 KW,12/8 pole is studied.First,according to the structure of the motor,several kinds of inductance are analyzed to deduce the mathematical model of the motor and generator.The 2D model of WEDSM is constructed to analyze the magnetic field distribution and electromagnetic parameters such as magnetic flux,inductance and so on under no load and load.Which lays a foundation for the study of system modeling.The modeling of WEDSM based on the inductance model is researched.Firstly,according to the characteristics of the self-inductance of armature winding and the mutual inductance between armature winding and the field winding,the inductance model and phase winding model are established.At the same time,based on the electromechanical energy conversion principle,the electromagnetic torque model of each phase and the cogging torque model are established,and the control module is set up under various control strategies to construct the motor control system.The accuracy is verified by simulation and the torque characteristics under various control strategies are analyzed.The generator model of WEDSM is also established by an optimized modeling method for the inductance of the armature windings and the mutual inductance between the armature windings and the field windings,which takes into account both the change in the field magnetization and the effect of the armature reaction.Besides,an accurate nonlinear modeling method of self-inductance of field windings is proposed based on the characteristics that self-inductance of field winding is only related to the excitation current and armature current of the phase tooth when its stator is aligned with the rotor.On this basis,the models of power generation system and cogging torque are built and the cogging torque model is established.Compared with the finite element simulation and the experimental results,the accuracy of the model is verified.Finally,the hardware system and software program of the WEDSM platform are introduced and experiments are carried on under a variety of control strategies.