Inmr acronym5/26/2023 ![]() ![]() By contrast, the gap in an EGLA has only two terminals. These were always enclosed in a housing and were a highly engineered component. The gap section of earlier generation SiC arresters consisted of hundreds of components including many series gaps, parallel resistors, field shaping coils, etc. Fundamental components of the EGLAĬLICK TO ENLARGE Advantages of EGLA Concept It is important to note that each component of the EGLA is significantly different from earlier gapped arresters. The gap is generally a single air gap in series with the arrester. The MOR is a non-linear metal oxide resistor and has roughly the same characteristics as a standard MOV arrester. The EGLA has two basic components: the MOR and the gap. Such FOW issues are of course not applicable for the protection of self-restoring line insulation. It seems unlikely that this arrester will ever evolve to the point where it can be used to protect equipment unless there is a breakthrough in gap technology that eliminates front-of-wave spark-over issues. In all cases, application requirements drive the dimensioning of the arrester. When applied to unshielded lines, the EGLA’s size may need to be substantially larger to handle 100 percent of the lightning current. Applied on a shielded line (with an overhead ground wire) and where the arrester is used primarily to mitigate back-flashover of insulators, they can be dimensioned to be quite small since the energy handling requirement is not as demanding as for unshielded lines. If used on a transmission line, they can be dimensioned so they do not operate when a switching surge is present but rather only conduct when a lightning surge appears. The most common application for these types of arresters is protection of lines. The EGLA has been in use worldwide at many different line voltages and appears to find greatest usage in Japan, Korea, China, France, Italy and Brazil. As of April 2008, IEC TC37 MT4 is still actively working on a test standard for this design of arrester. Also, the term ‘line’ was added since this arrester is most often applied for protection of distribution and transmission lines. After several meetings, the acronym EGLA was adopted to give this style of arrester easier reference. About 2001, the Japanese and the French National Committees introduced externally gapped arresters as a new work item for MT4 to deal with. The name externally gapped line arrester came from the activities of IEC TC37 Maintenance Team 4. ![]() This INMR article from 2014, contributed by Jonathan Woodworth, clarified the differences between the two alternative line arrester technologies and outlined the characteristics that make this design attractive for many line protection applications. However due to the negative characteristics of gapped technology when used in series with earlier silicon carbide (SiC) arresters, the EGLA has sometimes experienced problems in user acceptance. Combining these two yields a significant improvement in line protection and reliability options for electric utilities. Updated MaBug fixes.The externally gapped line arrester (EGLA) optimizes the positive characteristics of the oldest arrester design component – a series gap – and the newest arrester design component, namely the metal oxide varistor (MOV). Updated MaNow supports saving search queries from PubMed and Google Scholar to My Folders! Look for the DeepDyve button next to your search results to add an article to a folder youĪs always, find the articles that are available to read on DeepDyve by looking for the orange 'available' Updated ApYou can now keep track of any article you find in PubMed or Google Scholar in Updated ApUse DeepDyve to automatically keep track of what documents were interesting during your searches on PubMedĪnd Google Scholar! Find your combined document viewing history in the updated Updated Bug fixes and performance improvements. Updated See your Recent Activity directly from the popup!Īlso included: various bug fixes and improvements for automatically saving Recent Activity. Updated Updating popup to properly display Science Direct searches and articles in your Recent Activity Updated Adding support for Science Direct searches and articles in your Recent Activity Updated Bug fixes and minor improvements to metadata collection for Recent Activity. ![]()
0 Comments
Leave a Reply. |