Measurements and modeling of EMC, applied to cabling and wiring

A myriad of cables transport power and communication signals in larger buildings and installations. Cross talk between cables and connected equipment is a major concern. Regulations do exist, but often show to be insufficient to avoid undesirable coupling. The current thesis research addresses this problem and provides a tested model for the interference coupling in buildings, in particular those caused by lightning. The model should also give an insight in the reliability of cabling and wiring, even when not all details of the installation are known. This was the goal as proposed in the IOP-EMVT project 'Optimal cabling in buildings and installations qua EMC'. A newly built pharmaceutical plant acted as main test object. In the measurements, currents of 0.3 kA were injected in the lightning protection grid on the roof. Inside the building, 100 m long test cables followed the path of other installation cables on the ladders and trays. The measured current and voltage are typical for the other cables. A simplified model of the installation included most designed current paths. It was implemented in method-of-moments program FEKO. Measurements and model agreed that the roof steel skeleton carried about 80 % of the current and the intended lightning conductors 20 %. A nearby, non-intended conductor (an air duct) had to be included in the model to obtain acceptable agreement between the calculated current through a cable support and the measured one. For three types of cables, the measured voltages agreed with the currents when combined with the transfer impedance measured in the laboratory. The agreement allows extrapolating the model to real lightning. This has been done in two steps, the first and simple takes the cable transfer impedances into account; the second and more complicated also includes travel time and resonances in the installation. The differences between both are limited for the Profibus fieldbus cable and not for the 2-lead cable with steel armor. The transfer impedance of the cables showed the advantages of armored cables even inside buildings. Additional interconnects to ground constructions cause a reduction of the lightning current inside a structure. They reduce the excitation of internal building resonances and shift the resonance frequencies upwards. Unrealistic artifacts in model results should be avoided by including a sufficient number of interconnects. Other shorter experiments are presented. For example: measurements and calculations on the lightning safety of an electronic lamp driver have been carried out on request of Philips Lighting. Based on the knowledge developed, an effective remedy against unacceptably large damage could be given. Simple configurations serve as direct test case for the models, such as the current distribution over a set of two 70 m long horizontal grounding electrodes. We compared measurements and the FEKO model, with simple analytical expressions. The interesting frequency range is up to 1 MHz, of relevance for lightning and conducted interference in switched mode power supplies

LASER Tech Briefs, September 1993

This edition of LASER Tech briefs contains a feature on photonics. The other topics include: Electronic Components and Circuits. Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Fabrication Technology, Mathematics and Information Sciences, Life Sciences and books and reports

Analysis of relevant technical issues and deficiencies of the existing sensors and related initiatives currently set and working in marine environment. New generation technologies for cost-effective sensors

The last decade has seen significant growth in the field of sensor networks, which are currently collecting large amounts of environmental data. This data needs to be collected, processed, stored and made available for analysis and interpretation in a manner which is meaningful and accessible to end users and stakeholders with a range of requirements, including government agencies, environmental agencies, the research community, industry users and the public. The COMMONSENSE project aims to develop and provide cost-effective, multi-functional innovative sensors to perform reliable in-situ measurements in the marine environment. The sensors will be easily usable across several platforms, and will focus on key parameters including eutrophication, heavy metal contaminants, marine litter (microplastics) and underwater noise descriptors of the MSFD. The aims of Tasks 2.1 and 2.2 which comprise the work of this deliverable are: • To obtain a comprehensive understanding and an up-to-date state of the art of existing sensors. • To provide a working basis on “new generation” technologies in order to develop cost-effective sensors suitable for large-scale production. This deliverable will consist of an analysis of state-of-the-art solutions for the different sensors and data platforms related with COMMONSENSE project. An analysis of relevant technical issues and deficiencies of existing sensors and related initiatives currently set and working in marine environment will be performed. Existing solutions will be studied to determine the main limitations to be considered during novel sensor developments in further WP’s. Objectives & Rationale The objectives of deliverable 2.1 are: • To create a solid and robust basis for finding cheaper and innovative ways of gathering data. This is preparatory for the activities in other WPs: for WP4 (Transversal Sensor development and Sensor Integration), for WP(5-8) (Novel Sensors) to develop cost-effective sensors suitable for large-scale production, reducing costs of data collection (compared to commercially available sensors), increasing data access availability for WP9 (Field testing) when the deployment of new sensors will be drawn and then realized