Common Mode Noise Analysis for a High Step-Up Converter with GaN Devices

High Step-up converters have numerous applications in renewable energy systems and electric automotive industry. To improve the power density, an interleaved high step-up boost converter with coupled inductor was proposed. However, for practical applications it is compulsory that this topology must comply with the CISPR standards. Therefore, to identify the noise sources in the analyzed converter, an equivalent noise modelling is conducted. These models revealed the dependency of inductor windings on different noise sources. For experimental analysis of the conducted emissions of this topology, GaN FETs based prototype is designed. Several tests were carried out to find the effect of various factors on noise emission. As results of tests, 1) Increasing the switching frequency generates increase in the noise spikes 2) Noise emissions from the converter do depend on its mode of operation 3) High peaks of noise are generated at low frequency range by reducing the voltage transition time across the switch.