INDUSTRY VISIT REPORT: OMAN TRANSMISSION GRID SUB-STATION, IBRI

I. Introduction 

Twenty-six students, along with two lectures, N. Srinivasa Rao and Veera Nagi Reddy V, from the department, visited the Oman Transmission Grid Sub-Station in Ibri on Wednesday, 14 November 2018. 

This sub-station is responsible for transmitting and distributing electrical power. It is maintained by the Oman Electricity Transmission Company. 

In this sub-station, voltage is stepped down from 400KV to 220KV to 132KV to 33KV to 11KV. 11KV is further sub-divided into 415 V for sub-station lighting. Among other facilities, firefighting equipment is used to guard against unforeseen fire hazards. 

II. Purpose of the visit

The main purpose of the visit was to give students hands-on experience of the working system of transmission lines, underground cables, corona, insulators, circuit breakers, bus bars, lightning arresters, current transformer, potential transformer and earthing systems. The students who visited the site studied the aforementioned concepts as part of their course – Electrical Power Systems (Course Code: EEPW 2252).

III. Insights from the visit

Engineers from the Operation and Maintenance wing of the sub-station walked the attendees through the safety rules observed in the sub-station. They also explained: 

 the load dispatch centre in Muscat;

 the process how the sub-station receives electrical power from the generating station;

 the control room operations; 

 the methods they adopt to control feeders, transformers, and bus bars; and

 the 500 MVA power transformer, and cooling system which is used for the transformer;

Engineers in the sub-station also gave a demonstration of the protective and measuring equipment such as current and voltage transformers, auto-transformers, circuit breakers, lightning arresters, isolator operations, earthing transformers, earthing switches, neutral earthing, and disconnecting switches. 

The following was also shown to the team:

 the control room (which has remote control panels for 375/500 MVA transformers, 220KV relay panels, and 220KV bus coupler);

 the battery room (which consists of battery banks of 48 volts);

 the gas-insulated sub-station (where SF6 gas is used for insulation); and

 132KV power cables in the cellar.

IV. Outcome of the visit

Thanks to the visit, the students were able to:

a) receive practical and hands-on experience of many systems pertaining to the generation, distribution, and maintenance of electricity which they had earlier only studied theoretically as part of their course; and

b) clarify doubts – pertaining to various aspects mentioned in (a) above – in discussion with the engineers of the sub-station. 

Along with students, we would like to extend our gratitude to the company for the permission and support they provided to make our visit a success with the accomplishment of the objectives, and to the HoD, Mr Naseer Al Shamakhi and the HoS, Dr  Illankumaran. V, for arranging the visit for our students.