The Research Of Transformer's Stray Parameters In Gyrator-Capacitor Model

Magnetic component is one of the important part in power electronics system, and has obvious effects on converter volume, weight, current ripple, output dynamic characteristics, efficiency, current stress and voltage stress of the switch. An accurate model of magnetic component is the base for studying and analyzing, simulating and optimizing the design of magnetic components. With the developing trend of magnetic techniques towards high frequency, complanation, integration and cell array, the stray parameters of magnetic component have more and more distinct effects in converter. The relative slow development of magnetic techniques has become an obstacle of the advancement of power electronics. Therefore, it is significant to study the stray parameters of magnetic components.At the beginning, some kinds of magnetic models are introduced and compared briefly. And then, the gyrator-capacitor model is chosen as the basics of the magnetic analysis and simulation model to satisfy the requirements of power electronics engineers and system research, So the research of the description of leakage flux and stray capacitor in gyrator-capacitor model is performed in this thesis.A new gyrator-capacitor model with a leakage permeance capacitor is given in this paper, at the same time, a simple method for calculating the leakage permeance capacitor based on magnetic energy is given in the thesis. The method to calculate the leakage permeance capacitor of two kinds of complex windings structure is also presented in the paper indicating the universality of the given formula.The stray capacitor is explained and discussed in brief using conductor system. It is concluded that capacitor between two adjacent layers is in general the main part in all kinds of stray capacitors. The methods to get the equivalent value of several kinds of stray capacitor are presented. Both traditional transformer and flat transformer are exemplified. The stray capacitors of two windings configures are also been discussed.The comparision between the simulation results with proposed and conventional transformer model indicates the model's validity. A traditional transformer and a flat transformer are used to testify the calculation of winding stray capacitance and leakage permeance capacitance, the experimental results accord with the calculation results well, verifying the effectiveness of the proposed model. It provides effective support and help to the power electrics system design and optimization.