AAU logo

Nournai-Esfetanaj, Naser

Nournai-Esfetanaj, Naser

PROJECT TITLE: Study of Spectral Characteristics of Low Frequency Conducted EMI on Smart Grid Robustness 

PhD period: 2018.07.01 – 2021.06.30.
Section: Power Electronic Systems 
Research Programmes: Modern Power Transmission SystemsEfficient and Reliable Power ElectronicsE-Mobility and Industrial Drives
Supervisor: Pooya Davari
Co-Supervisor: Huai Wang
Contact Information

Funding: Department of Energy Technology.


In smart grid systems, power electronic converters are a key enabler as a cross-functional technology in the energy conversion process. In order to assure proper and reliable operation of smart grid systems, where a high number of the power electronic converters and mains communication systems are utilized, maintaining the generated conducted Electromagnetic interference (EMI) is an urgent factor conditioning the proper development of smart grids systems.

EMI as a result of the-inherent pulse energy conversion in power electronic converters appears over a wide frequency range and the generated non-intentional emission may partially or fully disturb the operation of other grid-connected electronic devices. While frequency ranges below 2 kHz and above 150 kHz are well covered with multitude standards, there is no general standard for the 2-150 kHz range. The main reason that this frequency range has gained a lot of attention than before is the extensive penetration of the power electronic devises and Main Communication System (MCS) due to their technological advancement within this range.

The main goal of this PhD thesis has three folds. Firstly characterizing low-frequency EMI emission of the power electronic based systems through closed loop impedance modeling. Secondly, developing suitable active and passive spectral shaping methods at device and system levels in order maintain the generated emissions following the grid-code. Thirdly, investigating new design factor considering EMI filters life-time degradation in order to further improve robustness of smart grid. Moreover, In order to validate the developed analytical models and low-frequency EMI mitigation techniques, simulations and experimental tests will be carried out.


Publications in journals and conference papers may be found at VBN.