SUBSTATION LAYOUT Design and considerations Layout diagram After bus arrangement is decided, Key diagram and then layout drawing should be prepared- to show actual position of each equipment Land plan- boundaries of the land acquired Civil works Electrical works Roads and paths for the movement of men and material Electrical works • For placing the various equipment in the switchyard. • The no. of columns and beams to support the busbars and incoming and outgoing connections depends upon the system voltage. • It should reveals Physical position of each equipment Distance between various equipments Phase segregation distance Phase to ground clearance Erection • In electrical layout, overhead wire (for protecting against lightning strokes) will be marked. O/H wire decides no. of columns and beams by the structural engineer. • Steel erection key- determines no. of various structures to be fabricated and helps the field erectors to erect the various structures at right positions. • No. of supporting structures (Las, Pts, CTs, CBs, Insulators, etc) should be finalized from the drawing • Supporting structures, columns and beams may be of steel or reinforced cement concrete. Clearances Various clearances for different voltages T o ensure satisfactory performance in service Safety of personnel in inspection, operation and maintenance work Electrical clearance Earth clearance Phase clearance (flash over) Section clearance-safety clearance to conductors (min distance bt unscreened live wires and work section. When screens are interposed, the distance is to be taken as a taut string measurement around the edge of the screen) Ground clearance- safety clearance to insulators (min distance bt insulators and work section) Work section (open type switchgear) • It should be capable of delimitation by screens or other means of restricting access to live conductors • Any convenient sub division of a switching station that include one or more items of equipment Busbar material • • • • Bus bar conductor Post type insulators Suspension insulator strings Terminal connectors, clamps, tees, etc Substation – Detailed Engineering Electrical Protection and Metering SLD Substation Layout Plan and Sections Substation Clearance Diagram Erection Key Diagram Earthing & Lightning Protection Lighting System Design Cable Routing and Schedule Control Room Equipment Layout Battery and LVAC System SCADA System Project Bill Of Materials Civil and Structural Foundation Design and Engineering Structure Design and Engineering Control Room Building Design and Engineering Lightning & Lighting Mast Foundation and Cable Trench Layout Storm Water Drainage System Road, Drain, Duct Bank Transformer and Reactor Foundation Transformer Fire Wall and Soak Pit Project Bill Of Materials Detailed enginnering System Studies and Reports • Data Collection • Power System studies for network expansion • Techno Economic Feasibility Studies • Detailed Project Reports in WB/ADB format • Financial Analysis • Year wise Implementation Schedule Project Management Project Scheduling and Control Progress Monitoring and Co-ordination Inspection and Expediting Project Development Site Selection through Distribution Planning Studies Selection of schemes Layout Configuration Permits and Approvals Project Engineering Basic and Conceptual Engineering Engineering Specifications Preparation of Tender Document Bid Evaluation / Recommendations Post Contract Engineering / Review and Approval of Vendor Documents Detailed Design and Drawings Site Services Supervision of Construction and Erection Protection co-ordination and relay setting Testing and Commissioning Preparation of O & M Manuals As-Built drawings Quality Control Implementation Measurement and Certification Procedure for drawing General Drawings Drawings of electrical plant and machines shall include, where appropriate: a. Overall dimensions; b. Terminal point details; c. Minimum clearances; d. Design pressures and temperatures for plant or plant items subject to pressure and temperatures higher than ambient; and e. Insets, where necessary, to ensure every item of the assembly is clearly shown. Requirements of Shop Drawings • Detailed shop drawings shall be prepared covering all aspects of the works. • The Designer shall review the shop drawings and any other technical submissions • to ensure that the proposed works comply with the design intent. Electrical Drawings • Electrical drawings for the installation shall be drafted in accordance with AS 1102 and shall include the following: a. Single Line Diagrams showing: − Bus rating and switchboard characteristics; − Current transformer ratios; − Circuit breaker and fuse current ratings; and − Ratings of capacitors, resistors and any other electrical devices. − Items shall be designated as per AS 3702; b. Substation Layout drawing to scale; c. Site Layout drawings to scale; d. Cable schedules (if required); e. Overall system diagrams, for communication and control systems showing cable types and system components; and f. Block cabling diagrams As-Constructed Drawings Provide “As Constructed” drawings that show as a minimum: a. The final locations of cables, pits, cable joints etc; b. Wiring diagrams for all equipment installed including termination diagrams; c. General arrangement drawings showing details of all equipment installed; and d. Any information as required facilitating operation and maintenance of the equipment. e. The “As Constructed” drawings shall form the basis of the Operations and Maintenance Manuals. System Drawings The designer shall prepare revised system documentation whenever an alteration is preformed to the reticulation system or a new system is installed. As a minimum the following documentation shall be provided in suitable hard copy and digital format in accordance with the Defence requirements a. Base HV single line diagram; b. Base HV geographic layouts; c. Substation/switching station schematics for all effected substations and switching stations; d. HV switchboards schematics for the main high voltage nodes such as CEPS and ISS, and e. LV distribution pillar schematics. Key diagram of 11kv substation Key diagram for 33kv substation Key diagram of 66kv substation Key diagram for protection Key diagram for indoor substation Reuse of scrap material
