Design and Analysis of a 24 k V PCB Bus for the Low Impedance Interconnect of a Multiphase PEBB- Based Converter

This work presents the design and analysis of a medium voltage (MV) printed circuit board (PCB)-based planar power bus rated for 24 kV with distributed capacitor daughtercards. This bus provides the low impedance interconnect between an external power supply and two phase legs of a 24 kV, 2 MW power electronics building block (PEBB) -based modular converter. The bus serves as a motherboard for capacitor daughtercards which are rated for 9
$\mu$
F 3 kV each. Electric field (E-field) analysis and parasitic extraction was performed via finite element analysis (FEA) using COMSOL Multiphysics and Ansys Electromagnetics for board- and system-level integration. Insulation performance for each component and the assembly was verified through partial discharge (PD) analysis using an Omicron MPD 600. The motherboard and capacitor daughtercard partial discharge inception voltage (PDIV) was evaluated on a layer-to-layer basis, in addition to the full assembly to ensure the system was PD free under normal operation.