Design and Implementation of a Peak Current Controlled Active Clamp Forward Converter for Railway Applications

This paper introduces an intermediate bus converter topology for a railway vehicle control unit's power distribution system that converts an input voltage (66V-154V) to a regulated 5V output with 100W rated power. Active clamp forward topology with peak current mode control used in this study has advantages like better dynamic performance and high power density while remaining relatively simple and economical. The structure of the power architecture and the mathematical modelling of the converter were presented. Simulation of the topology has been made using PLECS and experiments on a prototype was conducted. Both simulations and experimental results validated fast transient response to dynamic load changes with 0.14V voltage change and around 0.25ms recovery time to 50% load current changes, in addition to stable operation in a wide input voltage range.