An Experimental EMC Investigation of On-Board Interleaved Buck Converters

On board a satellite, there are different devices that operate from a common energy source called a power bus. Since there are many devices connected to the same power bus and they are in the close vicinity of each other, it is important that they are able to function adequately in the electromagnetic environment of the satellite without introducing intolerable electromagnetic interference to other devices. On-board devices often require voltage levels different from the bus voltage to function, and this is often produced by switching-mode power supplies (SMPS). Their switching-mode operation guarantees that there is less power loss during conversion; however, they also emit conducted and radiated noises into the direction of the power bus and the payloads. In the case of multiple SMPS powered by the same power bus, we can interleave their switching periods. Thus, their noises will cancel each other out on their common input. In this study, we are going to demonstrate the noise reduction of the interleaving method with a setup consisting of two DC-DC converters connected to a simulated power bus.