REDUCING COMMON MODE ELECTROMAGNETIC INTERFERENCE IN SINGLE-PHASE INVERTERS FOR THE NAVY INTEGRATED POWER ELECTRONICS BUILDING BLOCKS

Abstract

This research investigates the mitigation of electromagnetic interference (EMI) in Navy integrated Power Electronics Building Blocks (NiPEBB) to comply with MIL-STD-461G conducted emissions (CE) limit while minimizing passive filter requirements. These filters reduce power density and increase system weight, making them less desirable for naval applications where space and efficiency are critical. The primary objective of this research is to build and experimentally validate a novel single-phase four-leg inverter capable of meeting MIL-STD-461G CE limits without requiring bulky EMI filters. The proposed topology extends the previously validated four-leg inverter concept from three-phase applications to single-phase systems. The inverter utilizes a voltage controller with delta modulation as the inner control loop, which is implemented on a field programmable gate array (FPGA) for high-speed digital control. The inverter legs are switched in pairs, effectively canceling out theoretical common mode voltage (CMV) to minimize EMI at the source. A hardware prototype was built and evaluated in a laboratory environment. Experimental results demonstrate that the novel single-phase four-leg inverter meets MIL-STD-461G CE limits under specific conditions with only small bypass capacitors. This research contributes to the broader goal of NiPEBBs: the development of lightweight, EMI-compliant modular power electronics for naval applications.