Measuring and Separating Conducted Three-Wire Emissions From a Fault-Tolerant, NPC Propulsion Inverter With a Split-Battery Using Hardware Separators Based on HF Transformers

Conducted emissions on the traction battery's power cables in EVs must be limited to avoid unwanted electromagnetic interference (EMI). When designing an EMI filter, it is advantageous have information of common mode (CM) and differential (DM) noise levels. This article deals with measurement separation dc side's three-wire DM/CM a fault-tolerant three-level neutral-point-clamped (NPC) inverter split-battery system. Two hardware separators, based small-circuit highfrequency transformers, were developed identify CM, line-DM, phase-DM Their characterized CM DM rejection ratios for frequency range from 150 kHz 110 MHz are at least $-$ 33 21 dB, respectively. The separated NPC was measured, using inductive load, when operating two-level modulation, resembling normal operation possible under fault, A simple model used testbed module oscillation derived validate noise's resonance peaks/valleys. It has been seen that dominant, especially below 10 MHz, except oscillations. Furthermore, case clamping diode levels increased by about 3 dB.