Analysis Of Variable Inductor By Rotary Valve Structure And Preliminary Application In Self-tuned Filter

Control technology which used in many industrial sectors plays an increasingly important role in many areas of science and technology, cause it can improve labor productivity. Automatic control theory and electrical technology, electricity, electronics has a close relationship. Automatic control system often realized by circuit which are generally connected by wire with resistors, inductors, capacitors and power electronic devices and some other components. Using variable components can improve the performance of the control system, especially inductors has a close relationship with magnetic materials. Because the concept of magnetism is hard to understand, modeling magnetic field is complex, parameters of magnetic media is difficult to measure accurate, design and analysis of inductor has always been difficulty in the research and development of circuit elements and design of control system.Depending on whether the inductance value adjustable inductors can be classified into fixed inductors and variable inductance. Variable inductor is a important kind of traditional inductive, which can be used to adjust impedance of circut, control voltage, compensate reactive power, improve the stability of power systems and power quality. In harmonic suppression, diversification of electronic devices and automatic detection, variable inductance also has been widely applied.Function of power electronic devices in harmonic suppression, diversification and automatic detection aspect also has the broad application prospect.This thesis introduces the principle of variable inductance at first, then summarizes the current variable inductor and analyzes of its advantages and disadvantages.Second, thesis introduces the basic theory of electromagnetic analysis, including nonlinear characteristics of magnetic materials, several main measuring methods of complex permeability, magnetic circuit analysis method, Maxwell’s equations and the finite element theory. This provides the theoretical foundation for the subsequent qualitative and quantitative analysis.Then the variable inductor with rotating valve hardware structure and principles are described. First of all raw materials and components is introduced, including specifications and main performance parameters. Second, rotary valve parts manufacture and difficulties are introduced. Third, theory and qualitative analysis of the structure variable inductance are provided. The relationship between inductance and the rotary valve angular is established. Finally, magnetic circuit model is put, provide a basis for subsequent derivation.Then several main parameters of the variable inductance is deduced, including saturation point, magnetic resistance, the complex permeability, inductance and reactive power.On the basis of the above analysis, thesis using software Ansoft to simulate the rotary valve variable inductance. Then made experiment of spin valve type variable inductor, calculated the inductance value of different angles, get the quantitative expression of the inductance to prove the feasibility and practicality of the structure variable inductance.Finally, explored the application of variable inductors in tuned filter, and put out an improved type of five-dimensional visualization method which is compared with existing programmes more efficient.