The Research Of SRM With Isolated Magnetic Paths And Its Generation Control In A Wide Speed Range

Switched reluctance machine are being more and more widely used in general industry,household appliances, aerospace and other fields because of its simple and rugged structure,low cost, multi-controllable parameters, easy control and many other advantages. Thisthesis proposes a new type of switched reluctance machine which has U-shaped stator teethand independent magnetic circuit. Such a machine has external rotor and more simplestructure, which makes the cost more affordable. For single-phase switched reluctancemachine, the thesis also presentes a new kind of power converter topology which can workin two modes: the full winding excitation mode and the partial winding excitation mode.This thesis studies the development situation and basic theoretical knowledge ofswitched reluctance motor. First, the thesis describes the development history of foreignand domestic, and presents the research status and focus. Then the basic structure andworking principle, the mathematical description equations, and the control principle of aswitched reluctance machine are introduced in detail.According to the structure of the proposed switched reluctance machine with isolatemagnetic circuit, the thesis studies the characteristics of the following machine: thethree-phase switched reluctance motor which has three different sizes of U-shaped statorand the single-phase switched reluctance generator which has only one kind of U-shapedstator. The advantages, shortcomings and application limitations of the proposedthree-phase switched reluctance motor are given by simulating and analyzing thecharacteristic of such motors. For the proposed single-phase switched reluctance generator,the thesis makes the following research: the electromagnetic properties of three differentstructures of the switched reluctance machine with isolate magnetic circuit are contrasted,and the optimal structural design is given in the thesis； the structure parameter of theproposed generator is calculated; the electromagnetic characteristic of the proposedgenerator using three different winding turns is simulated respectively through the Maxwell3D finite element electromagnetic analysis software, and the result of simulation isanalyzed; the electromagnetic model of the generator is built in Matlab using theelectromagnetic simulation result and the electrical power generation process of thegenerator having three different winding turns is simulated respectively, the simulationresults are also analyzed; according to conclusions of the the design and simulation, a prototype of switched reluctance generator is created.At the end of this thesis, the working principle of the proposed new power convertertopology in two excitation modes are introduced, and the operating characteristics of thetwo modes are compared through simulation. It is verified that using part of the fieldwinding to excite can improve the efficiency of power generation at lower speed and gethigher input power and output power at higher speed.