This work deals with the flow of the electromagnetic energy through an idealized single-phase transformer supplied with nonsinusoidal voltage and supplying a nonlinear load. The electromagnetic flux components of the energy that flows from primary to secondary as well as the flux of energy stored in and ejected from the dielectric space surrounding the windings are identified and quantified. The electromagnetic flux components are correlated to well known instantaneous powers.Read full article
When procuring small transformers, the paramount criterion is often alleged to be the costs, while only the price is meant, not the costs the transformer causes during adaptation, fabrication of the finished device, the cycle of use and the recycling of materials afterwards.Read full article
Non-stop interruption-free applications in home, office and industry demand for a high quality and reliability power supply. Uninterruptible Power Supply (UPS) manufactures offer a great deal of solutions, but each application requires a particular solution. Selecting the best static UPS for an application is a cumbersome task for many customers. This paper reviews the IEC 620400-3 standard regarding static UPS performances and tests requirements and also proposes some new test not included in the standard.Read full article
Hard truths or soft concessions?
The U.S. National Petroleum Council recently published a major new report: 'Facing the Hard Truths about Energy: a Comprehensive View to 2030 of Global Oil and Natural Gas'.
It doesn’t come as a surprise that the peak-oil guys of APSO-USA (Association for the Study of Peak Oil & Gas) are not impressed. In the article: 'National Petroleum Council report comes up a dry hole' in the Energy Bulletin, they state that the NPC report doesn’t meet the promise of its title. A more interesting, close reading of the NPC report was done by Jerome a Paris, also in the Energy Bulletin.
A breakthrough in the NPC vision
Jerome a Paris sees two reasons why the report can be called a breakthrough in the vision of the NPC:Read full article
Mon, 08/27/2007 - 12:53
This webinar discusses some of the power quality contracts and classification systems used by distribution companies. It will show the different contracts used around the world by some groups of customers and utilities. It also discusses the roles of the regulator when allowing the market to agree on premium power quality contracts.
This webinar also describes the possiblity of classification of power quality at the point of supply for the most important power quality aspects (interruptions, voltage dips, harmonics, voltage fluctuations).
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The Power Quality Survey was conducted by the European Copper Institute (ECI) to investigate the consequences for EU industry of poor power quality among industrial sectors for which electrical energy is critical. These consequence amount to >€150bn annually, are mainly [>90%] experienced by industry and caused by power interruptions (dips, surges, transients and short interruptions). These losses represent a significant [>5%] proportion of the net profits made by the sectors under review.Read full story
Traditionally electricity networks have been built to transport electrical energy generated by large, central placed, power production units. The new, relatively small, distributed generation (DG) units are usually connected to distribution networks, not designed to host power generators. Most studies confirm that 10-15% penetration of DG can easily be absorbed in the electricity network without major structural changes.Read full story
… and the role of power utility companies
If we are to build a sustainable energy future for Europe, a key role will be reserved for electricity. Its simplicity and cleanliness at the point of use, combined with the feasibility of clean power generation, make it a preferred energy carrier.
That is the main conclusion of Eurelectric’s study 'The role of electricity'. A summary of that paper was released in March 2007. While it is easy to agree with the general conclusion, the study would gain relevance if it did not limit itself to advocating only those technologies in which power utility companies play a key role.Read full article
By the way, even if you proceed in the most efficient way and compensate the reactive power of magnetic ballasts right in place within the luminaire, one capacitor may suffice for no less than four lamps. In public and commercial areas you often see this type of square luminaires with four lamps rated 18 W each.Read full article