1.9 Isolated Bias Power Supply Architecture and Topology Trade-offs for HEV/EVs

The flyback topology has historically been the most widely used solution for isolated bias power in HEV/EV powertrain due to its low-cost, wide-input voltage range, and ability to support multiple outputs. HEV/EV power electronics engineers are facing more stringent requirements for power density, EMC performance, and system cost. A variety of topologies including flyback, fly-buck, open-loop push-pull, and open loop half-bridge as well as different power architectures ranging from a single central transformer with multiple output windings to a distributed architecture with individual bias supply for each load are beining considered to address these challenges. This presentation will cover the advantages and disadvantages of the various topologies and power architectures and will analyze test results from 4 TI designs to quanitfy the performance of the different topologies.