Abstract:
This paper presents the optimized design of a highfrequency
three-winding transformer for a triple active bridgebased
dc–dc converter used in an unfolding-based grid-tied multiport
electric vehicle (EV) charging system. To reduce the number
of passive components and thereby improve power density and
system efficiency, the appropriate spacing between the transformer
windings is determined using the H-field distribution,
which relates the winding placement to the resulting leakage
inductance. The accuracy of this estimation is further improved
by applying the Rogowski correction factor, and the resulting
spacing is implemented in hardware to achieve the desired
leakage inductance that provides the required tank inductance.
To ensure compatibility with a wide range of EV battery voltages
from 200 to 800 V, an LCL resonant tank is employed, and the
transformer winding on the EV side is designed to minimize
the reactive-to-active power ratio of the tank over this entire
voltage range. Reducing this ratio lowers the tank current
levels and the associated conduction losses, thereby improving
overall system efficiency. The transformer design is first validated
using ANSYS MAXWELL, then fabricated and tested with
a 5 kW, 100 kHz multiport converter prototype. Measured
leakage inductance closely matches analytical predictions, and the
experimentally obtained coupling and inductance matrices show
strong agreement with finite element analysis results. Finally, the
thermal performance of the proposed three-winding transformer
is validated via FLIR imaging, confirming a safe temperature
rise during steady-state operation.
See publication:
https://ieeexplore.ieee.org/document/11516833This publication pertains to:
Charging StationsPublication Authors:
- Aditya Zade
- Bryce Hesterman
- Shubhangi Gurudiwan
- Regan Zane