Brief Description of the Work undertaken by BEC Group

Engineering, Procurement, Construction, Testing and commissioning of 400/220kV IPP Grid Stations associated 220kV OHL works including 400kV & 220kV Gas Insulated Switchgear with Bus duct

Salient Features includes:

Construction of 400 kV IPP-3 GS in Sohar Port Area

ELECTRICAL - SCOPE OF WORKS

• Sixteen (16) bays of Indoor double bus bar single-phase encapsulated design of 400 kV, 4000A, 63 kA for 1 sec, SF6 Gas Insulated Switchgear (GIS).
• 11kV Switchgear of rating 2000A, 3Ph, 31.5kA for 3 sec.
• Auxiliary Transformers of rating 1000kVA, 11/0.415kV
• Station Protection system
• 400kV Synchronising Swing Panel & Phasor Measurement
• Station Control System (SCS) & LDC Interfacing
• Telecommunication System
• The Integrated Security System
• SF6 gas filling & evacuation plant, 400kV GIS online partial discharge monitoring system.
• HV/ MV / LV Power and Control Cables & Fiber Optic Cables & Accessories
• LVAC distribution board and Essential Distribution Board & Sub DBs
• 110V DC system
• 48V DC system
• Grid Station Earthing and lightning protection system, illumination system
• Fire Protection and Detection system, HVAC system and Drainage system

CIVIL - SCOPE OF WORKS

• The civil engineering works, associated building services
• Site clearance, backfilling, compaction, surfacing, grading and levelling of Grid Station plot, site mobilization, site office facilities & demobilization.
• Soil investigation including earth resistivity measurement
• Design and construction of 400kV GIS & Control Building with basement of 5 M height.
• Design and construction of all cable trenches/ducts with the boundary of the plot.
• Design and construction of boundary walls.
• Water supply system, sewage system
• Tarmac asphalted internal roads and Tarmac Access road to grid station
• Fire water Pump house

Construction of 400 kV GS in Sohar Free Zone (SFZ) 

ELECTRICAL - SCOPE OF WORKS

• Seventeen (17) bays, indoor double bus bar single-phase encapsulated design of 400 kV, 4000A, 63 kA for 1 sec, SF6 Gas Insulated Switchgear (GIS).
• Three (3) Power Auto transformers of rating 400/220/33kV, 500 MVA (ONAN/ONAF/ ODAF)
• Three (3) sets of (3-isolated GIB per transformer) Gas Insulated Bus Ducts between 400kV Switchgear and the primary of 500MVA Power Auto Transformers
• Two (2) outdoor Shut Reactors of rating 400KV, 50 MVAr (ONAN) connected in two OHL lines
• Two (2) sets of (3-isolated GIB per reactor) Gas Insulated Bus Ducts between 400kV Switchgear and the HV side of 50 MVAr Shunt reactor
• Four (4) sets of (3-isolated GIB per OHL feeder) Gas Insulated Bus ducts between the 400kV Switchgear and the 400kV OHL Gantry
• Four (4) sets of 400KV Surge arrestors (3 per circuit) in OHL feeders
• Two (2) number Earthing Auxiliary Transformers of rating 1000kVA, 33/.415kV, ONAN, ZNyn11
• Three (3) circuits of 220KV Cable (each phase length approx. 900mtrs) from 220KV side of 500MVA Transformer to other substation GIS switch gear
• Station Protection system
• 400kV Synchronising Swing Panel & Phasor Measurement Units  for outgoing cable and OHL
• Relay panels of OHL feeders, Transformer feeders, Bus Section and Bus Coupler shall be provided with independent Synchro-check relay
• Station Control System (SCS) & LDC Interfacing
• Telecommunication System
• The Integrated Security System
• HV/ MV / LV Power and Control Cables & Fiber Optic Cables &
• LVAC distribution board and Essential Distribution Board & Sub DBs
• 110V DC system
• 48V DC
• New Fire detection and alarm system, Fire protection and Fire fighting system
• Grid Station earthing and lightning protection system, Indoor and outdoor lighting
• Fire Protection and Detection system, HVAC system and Drainage system including drain pumps

220kV Remote End Works:

• Existing CRP Panels wiring modifications for 3 Nos. of 220KV Transformer feeder for Cable differential protection with replacing the existing relays with new relays.
• Integration of the new supplier Cable Differential Protection Relays with the existing Station control system.

CIVIL - SCOPE OF WORKS

• The civil engineering works, associated building services and architectural comprise the design, preparation of working drawings , provision of all plant, labour and materials and construction & maintenance of new substations
• Site clearance, backfilling, compaction, surfacing, grading and levelling of Grid Station plot
• Soil investigation including earth resistivity measurement for grid station design and facilities
• Storm water drainage arrangement including channels & pits.
• 400kV GIS and Control buildings along with basement and required, false ceiling and finishes including all associated building services such as ventilation and air conditioning, sanitary and water supply arrangement
• Electrical equipment foundations, including foundations for transformers with firewall and separate oil collection pit (150%) for transformer and reactor, foundations for Reactor & EAT etc. Fencing, access gates for complete transformer yard. Steel structure shed
• Fire water Pump house building with EOT crane, firefighting equipment foundations, structures, RCC Foundation for firewater tanks & pipe supports
• Boundary wall, main motorised sliding gates, access gates and electric fence wire protection
• Outdoor concrete cables trenches, cable ducts, pipe sleeves as required, Outdoor equipment supporting structures, and equipment foundations, grading, fencing, gates and spreading of crushed aggregates
• Tarmac asphalted internal roads and Tarmac Access road to grid station from nearest existing main tarmac access road
• Covered Car park shed suitable for six (6) vehicles
• Septic tanks / holding tank and soak away, drainage system, pipe sleeves etc.

Construction of 400 kV GS in Seh Al Makaram (SIS) GS

ELECTRICAL - SCOPE OF WORKS

• 11 Nos. bays, 400kV Gas Insulated Switchgear indoor type, rated 4000A, 63kA, 1 sec
• 400kV Gas Insulated Bus duct for the connection between 500MVA Transformer & 400kV GIS and 400kV OHL & 400kV GIS
• 06 Nos. 400kV outdoor Lightning Arrestors including support structures
• 400kV GIS relay panels including complete set of protection relays and SCS BCUs for GIS bays along with common alarm panel, 01 Synchronising panel and Busbar Protection panels for 400kV GIS
• 01 set of SF6 gas filling & evacuation plant, 400kV GIS online partial discharge monitoring & PMU for outgoing cable and OHL
• 03 sets of 500 MVA 400/220kV, YNa0 (d) connected, neutral CTs, complete fittings and accessories, OLTC, RTCC panels and Transformer Monitoring System
• 220kV Cu. XLPE cables between each 500 MVA, 400/220kV transformer and existing 220kV GIS & related termination
• 02 Nos. 33/.433kV, 1000kVA Earthing Auxiliary Transformer connected to the tertiary winding of 500MVA Power Transformers 1 and 3
• Station Control System (SCS) & LDC Interfacing
• GIS crane of 5 Ton and Fire Fighting Pump House Crane of 2 Ton capacity
• 33kV Cable, LV Power, Control and Instrumentation Cables & termination along with Cable Tray, conduits & accessories
• 01 set of LVAC distribution board and 01 set of essential Distribution Board & Sub DBs
• 02 sets of 110V batteries and 02 sets of Battery Charger along with associated distribution boards. 48/110V DC-DC redundant standalone power converter system including redundant 48V DCDB
• Grid Station Earthing and lightning protection system, illumination system (Indoor and Outdoor lighting)
• Telecommunication System, Integrated Security System and the Intelligent Plant Access Control System
• Fire Protection and Detection system, HVAC system and Drainage system including drain pumps

220KV SIS Grid Station Extension

• 03 Nos. 220kV GIS bays, 220kV GIS rated 2500A, 50kA, 1 Sec. (rating as existing at SIS GS)
• 220kV GIS relay panels including complete set of protection relays. Busbar Protection for 220kV GIS extension. Modification of Existing 220kV busbar protection panel
• Modification /reconfiguration of existing Substation Control System (AREVA PACiS) providing additional BCUs
• LV Power, Control and Instrumentation Cables & termination along with Cable Trays & accessories
• Earthing for the 220kV Extension works

CIVIL - SCOPE OF WORKS

• Site preparation includes Site Survey, site grading, site mobilization, site office facilities & demobilization. Sub soil Investigation and Soil Improvement
• Design and construction of 400kV GIS room with Cable trenches for LV power and control cable laying. Control building with basement of minimum floor to soffit height of 2.5m. The basement provided for control room, telecom room, LVAC & DC room
• Design and construction of all cable trenches/ducts with the boundary of the plot in addition to the cable trenches connecting existing 200kV SIS grid station with the new 400kV SIS grid station
• Design and construction of boundary walls.
• Demolishing of existing boundary wall separating the existing 200kV SIS grid station with the new 400kV SIS grid station
• Water supply system, sewage system including underground septic tanks, and rain water drainage network
• Design and construction of all outdoor equipment foundations, including foundations for Transformers with firewall and oil collection pit, foundations for EAT etc. Fencing, access gates, Steel structure shed
• Construction of tarmac access roads
• All civil engineering and building modification works required for the installation of extension equipment’s as per the scope of works. All required floor, wall openings for 220kV extension bays and cabling works
• New Fire pump house with fire water tanks as per OETC standard specification suitable for feeding existing 220kV GS and 400kV GS fire protection requirement.
• New fire pump house constructed under this project connected to existing 220kV Fire protection system
• Dismantle existing Fire pump house and fire water tanks & packed for long term storage and delivered to OETC stores