DC-DC Converters for EVs: EMI-Comparison of a Phase-Shifted Bridge to an Interleaved Buck Topology

Inhalt:
The conducted electromagnetic interference (EMI) caused by a DC-DC power converter interfacing an automotive electric battery and the 48 V board grid can eventually affect the operation of the battery management system at the battery side of an electric vehicle or could transfer emissions to the board grid, where the conducted and radiated EMI originating from the converters could influence the signal electronics of automotive components. This work takes into account hardware setups of two different converter topologies: a phase-shifted full-bridge (PSFB) and a two-phase interleaved buck (TPIB) converter, both for up to 3kW power and 400 V to 48 V voltage conversion. An analysis of the conducted and radiated emissions for half-load and full-load conditions is performed in buck operation mode. The results indicate the TPIB-topology having higher radiated emissions, higher differential mode emissions, but lower common mode emissions than the PSFB-topology.