TENDER DOCUMENT FORDESIGN, MANUFACURE, TESTING AND SUPPLY OF 132/33/11 KV, 50 MVA TRANSFORMERFOR132/33 KV SUBSTATION ATGHORASAL THERMAL POWER STATIONGENERAL TECHNICAL REQUIREMENTS & SPECIFICATIONGENERAL TECHNICAL REQUIREMENTS6.1 25/50 MVA 132/33/11kV Power Transformer For 132/33kV Sub-station atGhorashal Power Station.a. 132/33/11KV, ONAN rating 25/25/18MVA, ONAF rating 50/50/35MVA, out doormounting, 3 phase. 50 Hz, uniform insulation. 132 4x2 % KV (HV taps on-loadoperating 9 Nos. of taps), mineral oil immersed equipped with BCT. The supply oftransformer will also include suitable size (size will be confirmed during detailEngineering) of MS rail for placing of transformer on foundation. During submission ofthe bid the technical data requirement of BPDB shall be fully complied by the bidder. Incase of any deviation observed in bidders technical data from User’s technical data, thebidder’s bid will be declared non-responsive. The bidder will provide 1(one) engineer forexpert service during installation, testing and commissioning of the transformer for 15days. The following specification are prepared based on the existing one with a view toprocure an identical one because both will run in Parallel. Successful Bidder may visitGhorasal power station for taking necessary data form existing one externally bymeasurement for detail engineering.b. The insulation value of HV /MV/ LV sides are:(i) Highest system voltage : 145 / 36/ 12kV(ii) Basic insulation Level (BIL) : 650 / 170/ 75 kV(iii) Power frequency with standVoltage (1min) : 275/70/28 kV.The Insulation level of HV & MV Neutral Bushing shall be same as Phase Bushings.c. The HV bushing and bushing for the neutral shall be capacitor type, porcelain beingbrown glazed. The BCT fitted in the neck of each bushing shall have 2 core & 4 tappingof each core. The ratio, accuracy class and burden of BCT are as follows:HV BCT:(i) 1st core:No of tapping: 41st tap: 400/1A,3P20, 20VA.2nd tap: 600/1A, 3P30,30VA.3rd tap : 750/1A, 3P30, 75VA.4th tap : 1000/1A, 1P30, 30VA.(ii) 2nd core:No of tapping: 41st tap: 400/1A, class 0.2, 20VA.2nd tap : 600/1A, class 0.2, 30VA.3rd tap : 750/1A, class 0.2, 75VA.4th tap : 1000/1A, class 0.2, 30VA.Bushing for the neutral of HV side:(1) 1st core:No of tapping: 41st tap: 200/5A, 10P15, 15VA.2nd tap: 300/5A, 3P10,10VA.3rd tap : 400/5A, 3P20, 20VA.4th tap : 600/5A, 3P30, 30VA.(ii)2nd core:Same as 1st core:d. The MV bushing and bushing for the neutral may be of capacitor type or porcelain typewith outside glazed of brown porcelain. The BCT fitted in the neck of each bushing shall have 2 core & 4 tapping of each core. The ratio, accuracy class and burden of BCT are as follows:MV BCT:(i) 1st core:No of tapping: 41st tap: 400/5A, 3P20, 20VA.2nd tap: 600/5A, 3P30,30VA.3rd tap : 750/5A, 3P30, 75VA.4th tap : 1000/5A, 1P30, 30VA.(ii) 2nd core:Same as 1st core.Bushing for the neutral of HV side:(I) 1st core:No of tapping: 41st tap: 400/5A, 3P20, 20VA.2nd tap : 600/5A, 3P30, 30VA.3rd tap : 750/5A, 3P30, 75VA.4th tap : 1000/5A, 1P30, 30VA.(ii)2nd core:Same as 1st core:e. The LV bushing may be of capacitor type or porcelain type with outside glazed of brownporcelain. No CT required for the bushing.f. Values of resistance reactance of the transformer shall not be deviated by more than2% (two percent) of the BPDB’S requirements and the core & copper loss oftransformer shall not exceed 5% (five percent) of BPDB’S requirements. The above-mentioned values are the tolerance values to be maintained during factory testing ifexceeds the transformer will be rejected.The impedance voltage, core loss and copper loss of the transformer shall be:Impedance voltage at HV-132-kV, MV 33, kv at 50 MVA and at 750C:Between HV and MV winding = 11.568%Between HV and LV winding = 19.443%Between MV and LV winding = 6.051%Core loss at nominal voltage, normal ratio and at rated frequency = 37.914 kW.Total excitation current = 0.251%Full load copper loss at nominal voltage (HV=132kV, MV=33kV) normal ratio at ratedfrequency and at 750C:50MVA HV and MV winding = 271.712 KW35MVA HV and LV winding = 170.854 KW35MVA MV and LV winding = 130.092 KWg. The winding shall be capable of withstanding:14.3 times base current for 5 seconds.16.6 times base current for 4 seconds.20.0 times base current for 3 seconds.25.0 times base current for 2 seconds.The winding shall be of electrolytic copper, free from burs and splinter. Paper shall be used for conductor insulation.h. The insulating oil shall meet all requirements as defined by NEMA standard/ B.S. shall bechemically stable, free from acidity and other corrosive ingredients and shall posses highdielectric strength. Oil for first filling shall be shipped in non-returnable drums. 10% of thequantity required for a transformer is to be supplied in addition due to usual losses duringinstallation centrifuging etc.i. The transformer tank shall be of welded construction fabricated from high tensile steel plateand shall be designed to withstand full vacuum.j. The transformer shall have air seal cell type oil conservator tank (the oil surface is completely isolated from the atmosphere by installing an oil resistant rubber cell in the interior of theconservator) at the top. Transformer will be provided with 2 separate conservators (1for main tank and another for On load Tap Changer), which will be having provision for mountingseparate MOLG. One part to be connected with transformer main tank through BuchholtzRelay (with cocks on both side) and the other part with OLTC tank through another gas Relay (with cock either side). Both will have oil level indicate (visual) with contacts for medicating“LOW OIL LEVEL” in the control panel.k. Pressure Release Devices for both Main Tank and OLTC Tank shall be providedl. Silica gel Breather with glass window shall be provided for both halves of the conservator lank. m. The On-load Tap Changer operating device shall be equipped with local (manual and electrical) and remote electrical operating device with appropriate interlocking. The OLTC motor shall be 3-phase 400 V operating type. The mechanical position indication shall be there both at the tap changer as well as on the operating device. Contacts Arrangements shall be there for remote position indicator (by digital display system) of the tap. Appropriate glands for the entry ofcontrol cable shall be provided.n. Sufficient Cooling Fans (3-phase, 400V, 50 HZ) of adequate capacity shall be fitted on the body of the transformer for cooling purpose to achieve the ONAF rating over the averageambient temperature of 400C. There shall be a control device in weather proof housing fittedon the body of the transformer and equipped with control relay operated by sensing device of oil temperature inside the transformer and operate requisite No. of fans. Beside there shall be manual switching device of cooling fans.o. The Radiators shall be in banks, which can be filled with or removed from the beds of transformer tank. Sufficient radiators shall be provided to achieve the ONAN rating at average ambient temperature of 400C. Each bank of radiator must have two stop valve one of whichshould be fixed at the top and the other at the bottom.p. Beside the main components of the transformer the other features and accessories to be associated which are as follows:(i) Inspection hole with cover.(ii) Manhole.(iii) Nameplate with complete diagrams and main speculations.(iv) Upper and lower oil valves oil sampling valve and drain valve.(v) Ladder to climb up to top with barrier at the bottom.(vi) Thermometer for sending oil and winding temperature and display: WTI shallhave two contacts among them one will be used for alarm circuit and other will besuitable for intercropping of HV and MV/LV Circuit Breaker.(vii) All HV (132 KV) terminals shall be provided with appropriate connecting clamps to be connected with 636 MCM ACSR conductors. The LV (33 KV) terminalsshall have also connecting clamps appropriate for being connected with one 636MCM ACSR conductor. The neutral terminal shall have connecting clamps to beconnected with 2/0 HDBS wire. The size of conductors may be changed duringapproval stage.(viii) There shall be four wheels (flange type) suitable for mounting on rails and tocarry the transformer as a whole.(ix) The transformer shall have at least two grounding terminals on its body.All ferrous parts of the transformer shall be galvanized or painted withappropriate paints of MUNSELL NO-5 Y7/1. Transformer with maximum shippingheight (not exceeding 11 feet) will be preferred.q. One set of extra gaskets and one set bushing of each type is to be supplied with the transformer lot without extra cost.r. The loss capitalization of power transformer will be done by the following formula for evaluation.C = A + 25650 X FL.Where:C = Capitalized cost in Taka.A = Quoted C&F cost in Take.FL = Total consumption of cooling fans in KW.s. Make and Model of Tap Changer: The transformer will be fitted with MR, Germany make On Load Tap Changer (M111 500 Y Model)t. Color of Finish Paint: All the existing transformers at Ghorashal are having external Aluminum finish Paint, The same will be provided for the new transformer.u. Termination of tertiary: Tertiary (11KV) winding will be brought out side to tank top after closing delta winding inside through 3 external bushings. (Bushings will be supplied extra)v. Control scheme of Tap Changer: On Load Tap Changer control scheme of new transformer will be suitable for individual operation of transformer from Control room. Master – Follower, Individual operation facility will be provided in this unit.w. Terminal connector: Transformer will be supplied with terminal connectors suitable for connecting to 636 MCM ACSR conductors.x. Rails: The transformer will be supplied with 2 sets of rails (1 set having 2 pieces of length equal to length and breadth of the transformer).y. Shipping: Main Body in Nitrogen filled condition with pressure monitor and extra Nitrogen Cylinder.TECHNICAL PRTICULARS AND GUARANTEE SCHEDULEOF132/33/11KV POWER TRANSFORMER(To be filled up by the Bidder otherwise bid will be rejected)Sl. Description Unit BPDB’s Bidders No. Requirements Data01. Name of Manufacturer02. Type Out door03. Rated Power (ONAN/ONAF)- High Voltage (HV) MVA 25/50- Medium Voltage (MV) MVA 25/50- Low Voltage (LV) MVA 18/3504. Cooling system ONAN/ONAF05. Phase 3- phase06. Rated Voltage of Transformer- High Voltage winding kV 132- Medium Voltage winding kV 33- Low Voltage winding kV 1107. Rated Frequency Hz 5008. Maximum Temperature rise(Allowable over an ambientTemperature of 400C)- in Oil 0C 55- in winding 0C 6509. Total Excitation Current % 0.25110. Core-loss at rated frequencyand rated voltage at nominal tap kW 37.91411. Full load copper loss at nominalvoltage (HV-132kV, MV-33kv), atrated frequency and at 750C- 50 MVA HV and MV winding kW 271.712-35 MVA HV and LV winding kW 170.854-35 MVA MV and LV Winding kW 130.09212. Cooling fan losses during runningAt full ONAF capacity kW13. Impedance Voltage for HV/MV at at750C at 50MVA base (%)Tp 1 10.911Tp 5 11.568Tp 9 12.48114. Impedance Voltage for HV/LV at at750C at 35MVA base (%)Tp 1 18.500Tp 5 19.443Tp 9 20.79615. Impedance Voltage for MV/LV at at750C at 50MVA base (%) 6.05116. Highest System Voltage- HV/MV/LV kV 145/36/1217. Basic Insulation Level:- HV/MV/LVLightning impulse voltage (1.2/50 kV 650/170/75 Peakµs wave)18. Power Frequency WithstandVoltage (1 min)- HV/MV/LV kV 275/70/2819. (a) HV winding resistance Y at 320CTap11U-1N Ω0.75001V-1N Ω0.76251W-1N Ω0.7500Tap51U-1N Ω0.68751V-1N Ω0.68751W-1N Ω0.6875Tap91U-1N Ω0.62751V-1N Ω0.62751W-1N Ω0.6275(b) MV winding resist ance Ж2U-2N Ω0.036252V-2N Ω0.036252W-2N Ω0.03625(c)LV winding resistance For existing 13U-3W Ω0.011003V-3U Ω0.011253W-3V Ω0.0112520. On Load Tap Changer on HV side- Manufacturer- Type M.R Germany - Number of Taps M 111 500Y MODEL -Tap range 09- Step voltage % ±8-Rafted Through current V 2640- Basic Insulation Level A 400kV 65021. Bucholz Relay- Manufacturer- Type22. Vector Group Yn/Zn/D-1-1123. BCT particulars:(a) HV side:- No of core in each bushing Nos 02i. 1st core:No. of Tapping Nos 041st tap 400/1A, 3P20, 20VA2nd tap 600/1A, 3P30, 30VA3rd tap 750/1A, 3P30, 75VA4th tap 1000/1A, 1P30, 30VA ii. 2nd core:No. of Tapping Nos 041st tap 400/1A, class 0.2,20VA2nd tap 600/1A, class0.2,30VA3rd tap 750/1A, class 0.2,75VA4th tap 1000/1A,class0.2,30VA(b) Neutral of HV side:- No of core Nos 021st coreNo. of Tapping Nos 041st tap 200/5A, 10P15, 15VA2nd tap 300/5A, 3P10, 10VA3rd tap 400/5A, 3P20, 20VA4th tap 600/5A, 3P30, 30VA II. 2nd core: Same as 1st core(c) MV side:No. of core in each busing Nos 02i) 1st core:No. of Tapping Nos 041st tap 400/5A, 3P20, 20VA2nd tap 600/5A, 3P30, 30VA3rd tap 750/5A, 3P30, 75VA4th tap 1000/5A, 1P30, 30VAII. 2nd core: Same as 1st core(d) Neutral of MV side:No. of core in each bushing Nos. 02i) 1st core:No. of Tappin Nos. 041st tap 400/5A, 3P20, 20VA2nd tap 600/5A, 3P30,30VA3rd tap 750/5A, 3P30, 75VA4th tap 1000/5A, 1P30, 30VAII. 2nd core: Same as 1st core(e) LV side No CT required24. Weight:with Oil Kgwithout Oil Kg25. Dimensions:Length x Width x Height mm26. Dimension of rail As per User’s existingConfirmed during detailEngineering.Facts about the tender:We need your competitive quotation forDesign, manufacture, testing and supply of 132/33/11 KV , 50 MVA Transformer including all accessories etc. as per Tender. (Quantity - 1 nos.).Pleased to enclose herewith the GENERAL OUTLINE ARRANGEMENT OF EXISTING TRANSFORMER: =========================================================================== SCOPE OF THE CONTRACTScope of supply include design, manufacture, testing, factory test witnessing, supply of necessary equipment and materials and expert service for installation testing and commissioning (as listed).i) Supply of recommended Electrical functional (Operational) detailed drawings.ii) Supply of recommended Electrical wiring connection detailed drawings including erection.iii) Supply of recommended detailed testing instructions and recommended results and testing procedures at site.iv) Supply of manufacturers booklets, catalogues, instruction manuals (Operation & Maintenance) in English Language showing the type of manufactured, design standards, detail ratings (technical), name of manufacturer, photos etc. for transformer.v) Supply of control wiring diagram of equipment,========================================================================= GENERAL LIST OF EQUIPMENT AND MATERIALSa) 1 (one) No three phase 132/3311 KV, 50 MVA Transformer for Thermal Power Station.==================================================STANDARD SPECIFICATIONSAll materials and equipment supplied shall comply with the relevant current IEC standard as specified unless otherwise permitted in this Contract, Specification or specifically agreed in writing by the Engineer/Consignee.。
