IEEE Miami Section in Conjunction with Energy Systems Research Laboratory at Florida International University is pleased to invite you to lecture on

Evaluation of Electromagnetic Interference Issues for EMC Compliant Product Designs

by Dr.Osama A Mohammed
Ph.D, Fellow IEEE, Fellow ACES, Professor of Electrical and Computer Engineering, Energy Systems Research Laboratory, Florida International University

Date: Friday, March 1st, 2013
Time: 10:00 AM to 12:00 PM
Place: Room EC-3753 in the third floor of FIU College of Engineering and Computing
10555 W. Flagler Street, Miami, Florida, 33174.

Abstract: Detailed physics based computational electromagnetic field models of multi component energy systems enable the evaluation of realistic waveforms of voltages and currents for low and high frequency operation. These models also enable inclusion of practical effects such as parasitic elements, leakage saturation, and switching patterns during the system operation. This is essential for studying signatures from individual components and connected systems which is necessary during the design stage. These models also enable the evaluation of conducted and radiated electromagnetic fields in machinery, cables and power converters used in multi component energy systems. The models enhance our ability to determine their signatures and EMI interactions as well as evaluate the effectiveness of connecting controllers and/or other components.
Including detailed physical parameters such as geometrical features, material and thermal models in addition to their variation during their dynamic operation, yields the satisfaction of accurate levels of design objectives which can prove to be useful in devising mitigation strategies such as attenuators and shields. These studies are necessary for product design and for the product to be compliant from EMC point of view.
In multi-scale multi-component system, a number of active and passive components exist and are responsible for the production of unwanted ground currents. The paths to ground allow low and high frequency currents to close a loop between the components. Grounded connection points form paths through high frequency ground capacitors. This current flow between grounding points, of the various components, occur due to the unbalancing of loading conditions, inter-component fault condition, switching activities and associated harmonics. The high frequency portion of the current due to switching devices couples the control circuits through low-voltage low-current elements and negatively affect the operation of the system.
From an electromagnetic signature point of view, the low and high frequency currents form loops passing this current and the resulting electromagnetic field will radiate in the surrounding environment. Any current loop with either DC or AC currents in the operational system will cause signature issues. If the amplitude of current is large enough to produce detectable field, the signatures must be evaluated for specific applications in order to develop mitigation strategies.
In this presentation, we will show modeling details and procedures to quantify signatures and EMI of actual physical components in several examples.