Integration of High Leakage Inductance to HFHP Transformer in High Power Converters Vs the Use of a Discrete Inductor

Abstract:
In the magnetic experts’ point of view a low leakage inductance transformer is an efficient transformer. Generally, research on magnetic technologies needs to be carried out to improve the primary and secondary linkage and thereby to achieve a low level of leakage field. The requirement for high power high frequency transformers of tens or even hundreds of kilowatts is increasing. These transformers are part of high-power converters that are used in electric vehicle charging and similar applications. The power conversion topologies such as LCC, LLC resonant converters deployed in these converter constructions use a resonant inductor. It is becoming the practice that the use of the transformer leakage inductance or even an increased leakage inductance integrated to the transformer is used by system designers as the resonant inductor over the use of a discrete resonant inductor. Sufficient and quantifiable information is not available to understand the advantages and disadvantages of this approach. This paper presents this information by considering fine details of magnetic designs of high-power high frequency transformers and quantifying the advantages and disadvantages of this approach which is a highly useful knowhow for the power electronics industry.