• Milan Modi
• Hiren Rana

This paper focuses on the design as well as proper sizing of electrical equipment in power transmission substations operating at various voltage levels from 33 kV to 220 kV. The study covers equipment such as power transformers, circuit breakers, isolators(disconnector), current transformers (CTs), lightning arresters, and potential transformers. A case study of a 220/33 kV pooling substation is presented using AutoCAD software, along with the a single-line diagram (SLD) that outlines the power flow and equipment ratings across the system. The proper selection of equipment ratings through proper sizing is important for achieving stability and reliability of power supply, while also ensuring the efficiency of substation operations as well as safety. The study highlights the important role of equipment sizing in the development of a dependable and efficient power transmission substation.

Power Substation, Substation Equipment, Equipment Sizing, Designing, Single Line Diagram, Auto-CAD.

"Evolution of Design Parameters of EHV Substation Equipment & Their Sizing", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.12, Issue 6, page no.g560-g565, June-2025, Available :http://www.jetir.org/papers/JETIR2506670.pdf

"Evolution of Design Parameters of EHV Substation Equipment & Their Sizing", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.12, Issue 6, page no. ppg560-g565, June-2025, Available at : http://www.jetir.org/papers/JETIR2506670.pdf