Accurate & Fast Modelling of Transformer Leakage Inductances
Accurate & fast models of the transformer leakage inductance are crucial for optimisation-based design of galvanically isolated power electronic converters. These converters are key elements in several important applications such as photovoltaics, traction applications, and grid control. Power electronic converters are usually designed with optimisations that create up to several ten thousands of virtual prototypes and calculate their physical properties such as the transformer leakage inductance. Due to the high amount of virtual prototypes, the models need to be rapidly executable as well as accurate to deliver results within a reasonable amount of time.
Models of the transformer leakage inductance are investigated, developed, and extended at HPE. Special focus is given to analytical models that are particularly fast to execute. Some of these models are more than 100 years old, long before powerful numerical calculation tools and computers were available. Today, the focus is to find the best models for certain transformer types and to further extend and develop the models to increase their scope and accuracy.
The transformer leakage inductance models are widely based on multiple 2D cross sections of the transformer. Useful assumptions and simplifications are chosen to find analytical and compact solutions to the governing electromagnetic differential equations. With this technique, Double-2D and Triple-2D models of multiple transformer types have been developed and successfully verified with measurements and 3D FEM simulations.