Provides society information that may include news, reviews or technical notes that should be of interest to practitioners and researchers.
Provides society information that may include news, reviews or technical notes that should be of interest to practitioners and researchers.
Provides society information that may include news, reviews or technical notes that should be of interest to practitioners and researchers.
Provides society information that may include news, reviews or technical notes that should be of interest to practitioners and researchers.
Power transformer (PT) energization implies a large inrush current during the transient. These inrush currents produce a malfunction of the protection systems, especially of the differential protections. Moreover, in some weak power systems they can produce inacceptable voltage reduction that implies disconnection of critical loads. For these reasons, there are some inrush current mitigation techniques. One of these techniques is based on the use of a reduced-power auxiliary transformer, known as premagnetization transformer (Pre-MT). This technique is very popular in the marine industry. In this article, the reduction of the power rating of the Pre-MT is studied. The capacity requirement for the Pre-MT can be reduced through the correct dimensioning of the voltage ratio. For this purpose, several tests have been performed on a 1,000-kVA PT by using different Pre-MT with taps. The results obtained are satisfactory as the inrush current of the main PT has been reduced up to 250 times, reaching only 0.4% of its rated capacity. Afterward, electrical and thermal simulations were performed to go a step further in the Pre-MT sizing. It was concluded that the required Pre-MT rated power can be reduced by 1,000 times the main PT one without jeopardizing either the integrity of the equipment or the premagnetization performance.
Provides society information that may include news, reviews or technical notes that should be of interest to practitioners and researchers.
Provides society information that may include news, reviews or technical notes that should be of interest to practitioners and researchers.
Provides society information that may include news, reviews or technical notes that should be of interest to practitioners and researchers.
Provides society information that may include news, reviews or technical notes that should be of interest to practitioners and researchers.
THE NATIONAL ELECTRICAL CODE (NEC) IS PERIODICALLY revised to enhance efficiency, account for technology development, and improve standard safety practices. Code changes made in the 2023 edition significantly impact various industries, particularly regarding the use of prefabricated structures in brownfield applications. One key amendment is the egress requirement added to sections 110.26 and 110.33 for equipment under and over 1,000 V. This code requirement is to be treated independently from working clearance and specifically necessitates that 24 in of egress are made available in all aisles while equipment doors are concurrently open. The implication is that buildings will be designed with larger footprints and additional shipping splits and will likely become more expensive to construct. Engineers must adapt to provide innovative design methodologies to meet these demands. This article reviews the egress code requirements, impacts on industries, and some of the devised strategies to meet standards and promote a safer electrical infrastructure.
