A 16 kV PCB-Based DC-Bus Distributed Capacitor Array with Integrated Power-AC-Terminal for 10 kV SiC MOSFET Modules in Medium-Voltage Inverter Applications

This paper presents the insulation design and assessment of a medium-voltage (MV), printed circuit board (PCB) based dc-bus distributed capacitor array. A generalized insulation design process is introduced with considerations for insulator material stress as well as surface discharge on external interconnections. Finite-element analysis (FEA) simulation studies of the multilayer PCB bus are used to analyze several approaches to control electric field distribution in the design layout. A specific implementation of a dc-bus for a 16 kV rated MV three phase inverter is described to demonstrate the proposed design procedure to achieve partial discharge (PD) free operation up to 18 kV (for 10 % design margin). The designed dc-bus also features a low inductance, modular architecture to improve the power density and specific power of the MV system. Experimental results of partial discharge behavior are presented for insulation design validation.