Improved Density and Temperature Range of In-vehicle Power Converters: High Frequency Power Supplies for High Temperature Environments

Principal Investigator: Juan Rivas, University of Michigan, jmrivas(at)
Student: Wei Liang, University of Michigan
Government: M. Abul Masrur, U.S. Army TARDEC
Industry: John Glaser, GE Global Research

This work began in 2012 and was completed in 2013.High Frequency Power Supplies for High Temperature Environments

The continuous trend towards vehicle hybridization and electrification and the desire to improve vehicle performance and passenger comfort has brought into today's vehicles a wide range of accessories, instruments and sensors plus an associated increase in the demand of electric power. The vigorous upward trend in electric power use has been a constant feature on new vehicles for decades with no prospect of subsiding for decades to come. The hunger for more electric power in automobiles will challenge existing power electronic systems to keep up at becoming lighter and more efficient while handling increased loads while performing reliably in harsher environments.

In the "under the hood" environment, where most power electronic systems reside, temperatures are high which is detrimental to the lifetime of many electronic components. Aggressive derating is needed when selecting components as well as complex, heavy and expensive thermal management to maintain the junction temperature of power devices within their operational limits. Many of the heavy power electronic system blocks found in today's hybrid vehicles require liquid cooling and expensive ceramic substrates to maintain junction temperatures under 125°C.

It is the objective of this program to study and develop power electronic topologies amenable to high temperature operation. Specifically we are aiming for the design of dc-dc converters rated for ambient temperatures well in excess of 175°C. The goal is to reduce or eliminate the need for expensive thermal management solutions that currently add weight and complexity to power electronic systems. These efforts can enable new applications requiring power converters mounted on the engine or near the exhaust or catalytic converter while at the same time setting new milestones in power density.


  • W. Liang, J. Glaser, J. Rivas, "13.56MHz High density dc-dc converter with PCB Inductors", IEEE 28th Annual Applied Power Electronic Conference and Exposition (APEC), Long Beach, CA, 17-21 March 2013.
  • W. Liang, J. Glaser, J. Rivas, "13.56 MHz High Density dc-dc Converter with PCB Inductors," IEEE Transactions on Power Electronics, no.99, pp.1,1, 2014.