Integrated Super Planar Inductor-Rectifier Design for EV Drive

Abstract

Power Density and cost are the key design criteria for the modern power electronics unit in Electric Vehicles (EVs). EVs widely adopt inductive wireless charging technology, which contains the receiving coil and the AC-DC converter on the vehicle side. However, the vertical space on the chassis for charging electronics is very limited. Moreover, with a non-compact package comes a high damaging probability due to unpredictable road conditions, higher costs, and vehicle integration issues. This research presents the concept of distributed planar magnetics with the integrated rectifier hardware design for the vehicle side charging electronics by combining the concept of planar-distributed magnetics with the design space optimization research. A planar-distributed inductor module consisting of 16 EI cores with PCB-embedded windings was designed, modeled (using a novel high-fidelity model), and fabricated using the design space optimization technique, which resulted in a 66% increase in the power density. This research treated and solved the power density problem as an optimization problem considering every constraint involved and presented a thorough investigation from the design space utilization, power loss, loss and frequency relation along with the magnetostatic and electrostatic analysis perspective. It also provides a comparative study of various materials for the inductor fabrication keeping in view the automotive application environment. Moreover, a hybrid approach (metalcore and FR4) PCB was used instead of a regular FR4 PCB after an in-depth study and performance comparison.

Keywords

• Electric vehicles
• wireless charging
• power density
• power converters
• planar inductor
• distributed magnetics