INTRODUCTION
A compact substation is a type of outdoor substation that integrates high-voltage switchgear, transformer, and low-voltage power distribution devices in a single unit. It has three separate compartments for different functions: the high-voltage room, the transformer room, and the low-voltage chamber. The high-voltage room contains the switchgear that connects or disconnects the substation from the power grid. The transformer room houses the transformer that steps down the high voltage to low voltage. The low-voltage chamber distributes the power to the consumers through various circuits and devices.
Compact substations are designed to save space, reduce installation time, and cost, and improve reliability and safety.
Compact substations are having no risk for fire, explosion, severe pollution, chemical corrosion, or severe vibration.
COMPACT SUBSTATION TECHNICAL SPECIFICATION
This document provides Technical Proposal for 11/0.415 KV, 800 KVA Compact Substation (CSS)
• 11 KV Outdoor type enclosure having Modular construction of Galvanized Sheet Steel of thickness 2mm for Load Bearing Member and 1.5mm for Non-Load Bearing Member with 4mm CRCA base frame.
• The Enclosure shall have IP65 degree of protection for HT & LT switchgear compartment & IP23 degree of protection for Transformer compartment.
• The enclosure exterior shall be Powder Coated (RAL 7032 or As Specified by Purchaser).
• The bottom base frame shall be welded and black painted Channel structure with lifting arrangement for the completely assembled Substation.
• Each compartment will be provided with the door and pad locking arrangement.
• The Compartment illumination lamp with door operated switch shall be provided for each compartment.
• Interconnection Between HT switchgear & Transformer using 1C x3C x 95Sq.mm XLPE Single core copper cable & Interconnection between Transformer & LT switchgear using Copper Busbars.
• Internal earthing connections by using Copper Strips including Transformer body including Transformer Neutral. (Only internal Earthing Connection)
IEC STANDARDS APPLICABLE FOR THE PRODUCT DESIGN
• Compact substations: IEC61330
• MV metal enclosed Switchgear: IEC 62271-200, IEC 60298
• Switch Disconnector (Isolators), and earthing Switches: IEC 60694-60129-60265
• Power Transformer: IEC 60076
• Low voltage switchgear: IEC 60439-1
• Low Voltage breakers: IEC 60947-2
HT COMPARTMENT
• Proposed Make: CG / Siemens / ABB / Schneider
• HT Compartment consist of 11 KV 630 Amp, 21kA, Ring main unit SF6 Gas Insulated, Non - Extensible, Manual operated, 3 VCB & 1 Isolator with standard accessories in SF6 insulated Stainless steel enclosure.
• Series trip, self-powered microprocessor based numerical over current and Earth Fault (IDMT+Inst.) relay protection.
• Interconnection between HT switchgear and transformer using 1Cx3x95 sq.mm Copper unarmoured XLPE Cable.
• Numerical Relay (50,50N,51,51N) with RS485 communication port – 1 Set.
• Protection CT shall be 40/1A 5VA5P10. -1 Set.
• Manometer – 1 Set.
• Operating handle – 1 Set.
• Cable termination boots – 1 Set.
• Voltage presence indicator - 3 Nos.
• Mechanical Indication for Breaker & LBS ON/OFF/EARTHED - 1 No.
• Fault passage indicator incoming LBS - 1 Nos
THE TRANSFORMER ROOM
TRANSFORMER SPECIFICATION:
• 800 kVA, Copper wound, distribution Transformer.
• 11/0.433 kV Cast Resin Type Dry type
• Vector Dyn-11
• Impedance 4.5%
• Transformer shall have Delta on HV side & Star on LV side with On Load Tap Changer with AVR & RTCCP: +5% to -10% in steps of 2.5%
• Winding temperature alarm & trip contacts on transformer compartment
• Necessary louvers and forced ventilation.
• Class F Insulation
• Temp Rise 90ºC
• Losses: At 50% Loading: 3.88 kW, At 100% Loading: 10.24 kW
LV COMPARTMENT
LV Compartment consisting of multifunction meter with V, I, F, P & E with RS 485 Connectivity with LT CTS of appropriate rating, Indicator Lamps for R Y B Indication Led Type, Space for fitting 3 Ph 4 wire electronic meter in sealable compartment with 3 Nos CTs of required rating, Copper Bus-bar - On LV Side, wiring for control with PVCV insulated 1.5 Sq.mm Copper wire for voltage & 2.5 Sq. mm for CT circuits.
• 1250 Amp Copper Busbar Incomer from transformer 1 No 1250A, 4P, 415V, 50Hz, MCCB with Microprocessor based O/L, S/C, E/F release. 1 Nos 415 Volts, 50 kA, 1250 Amp, 4 Pole MCCB LSIG:
• 1 Nos Metering Ammeter, Cl-1.0, Digital
• 1 No Voltmeter, Cl-1.0, Digital
• 1 No Switches Ammeter selector,
• Voltmeter selector. 1 No
• Indicating Lamps sets including CB Status and Trip Indicators,
• LT CTs 600V, Resin cast, Single phase, 1250/5A, 5VA, Cl 1.0