This is the most rigorous and definitive approach. A transformer is subjected to a specified number of short-circuit applications (typically three single-phase tests for each tapping position) at a defined peak current that simulates the worst-case asymmetrical condition. During the test, oscillograms of voltage and current are recorded. After the test, the transformer must pass a repeat of routine tests (no-load loss, load loss, impedance voltage) and a lightning impulse test. Finally, an internal inspection is performed to detect any winding displacement or deformation. If all criteria are met, the transformer is certified as compliant.
: “Bridging the Gap: Evaluating the Accuracy of IEC 60076-5 Annex A Equations using Finite Element Analysis.” iec 60076-5
For the purpose of short-circuit testing and design, transformers are divided into three categories based on their rated power: iTeh Standards Category I: Up to 2,500 kVA. Category II: 2,501 kVA to 100,000 kVA. Category III: Above 100,000 kVA. Methods of Demonstration This is the most rigorous and definitive approach
The test involves: