Research On The Optimizing Design And Simulation Of Planar Transformer Based On Integrated Software Platform

The drive towards higher power densities and overall lower profile in switch mode power supplies (SMPS) has exposed a number of limitations in the use of conventional transformer structures. In order to achieve higher power densities, it has to increase the converter switching frequency to achieve passive component size reduction. However for conventional wire wound transformers this leads to problems of increased loss due to the skin and proximity effects in the round conductors particularly at frequencies above 100 kHz. One possible solution is to employ planar transformer consisted of low-profile core and planar winding fabricated on a printed circuit board (PCB). Unlike conventional wire wound transformer, planar transformer offers many advantages, such as lower profile, good thermal characteristics, small leakage inductance and repeatability, so it is a good solution for high power density high frequency (HF) SMPS. Its research and application are growing in the last decade. However, due to the high switching frequency up to several hundred kHz, even more than 1MHz, planar transformer is also affected by many HF effects like skin and proximity effects. These HF effects produce ac resistances, leakage inductances and distributed capacitances that increase the losses of the SMPS, produce parasitic oscillations with dangerous high voltage spikes, and must be reduced the performance of the SMPS, moreover, reducing leakage inductance has the usually unwanted effects of increasing distributed capacitance, hence an optimal design of planar transformer is necessary to take into account all the parasitic effects.This paper describes a method of optimizing planar transformers'design based on integrated software platform iSIGHT. Through integrating the circuit simulation tool Saber and Maxwell 3D to the optimization tool iSIGHT, the parasitic effects on planar transformers are studied carefully, and a new method to avoid parasitic oscillations with dangerous high voltage spikes to improve the SMPS performance is established. Hence an optimal design of planar transformer is obtained. The main jobs and conclusions as follows:Firstly, the special planar structure and winding fabricated means of planar transformer is in-depth studied, including the principle of parasitic effects, their disadvantages to the SMPS performance, and methods to reduce these effects. Hence a high frequency planar transformer model suitable for design, optimization and circuit...