TENDER ***UMENT FOR DESIGN, MANUFACURE, TESTING AND SUPPLY OF 132/33/11 KV, 50 MVA TRANSFORMER FOR132/33 KV SUBSTATION AT GHORASAL THERMAL POWER STATION CLOSING DATE: 30-06-2004 at 11-00 A.M. PROJECT REQUIREMENTS Description of the overall Projects Bangladesh Power Development Board (BPDB) intends to procure one (1) 132/33/11 KV, 50 MVA three phase Transformer for Ghorasal Thermal Power Station. Description of the same is given below: There are 2 (two) Nos. of 132/33/11KV, 25,000/50,000KVA Transformer at 132/33 sub-station at Ghorasal Power Station. Out of them one has been damaged. So, at present one 25,000/50,000KVA Transformer is in operation. The program of this project is to replace the damaged 25000/50000 KVA, 132/33/11 KV transformer by the same size and characteristic transformer and will run in parallel with the existing one. The description of the Transformer is described in this file later on. SCOPE OF THE CONTRACT Scope 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, If drawings are drawn by “Auto Cad”. Compact disk (CD) with drawings to be supplied to Design & Inspection-1, BPDB, Dhaka. GENERAL LIST OF EQUIPMENT AND MATERIALS a) 1 (one) No three phase 132/3311 KV, 50 MVA Transformer for Ghorasal Thermal Power Station. STANDARD SPECIFICATIONS All 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. vi) GENERAL TECHNICAL REQUIREMENTS & SPECIFICATION GENERAL TECHNICAL REQUIREMENTS 6.1 25/50 MVA 132/33/11kV Power Transformer For 132/33kV Sub-station at Ghorashal Power Station. a. 132/33/11KV, ONAN rating 25/25/18MVA, ONAF rating 50/50/35MVA, out door mounting, 3 phase. 50 Hz, uniform insulation. 132 ± 4x2 % KV (HV taps on-load operating 9 Nos. of taps), mineral oil immersed equipped with BCT. The supply of transformer will also include suitable size (size will be confirmed during detail Engineering) of MS rail for placing of transformer on foundation. During submission of the bid the technical data requirement of BPDB shall be fully complied by the bidder. In case of any deviation observed in bidders technical data from BPDB’s technical data, the bidder’s bid will be declared non-responsive. The bidder will provide 1(one) engineer for expert service during installation, testing and commissioning of the transformer for 15 days. The following specification are prepared based on the existing one with a view to procure an identical one because both will run in Parallel. Successful Bidder may visit Ghorasal power station for taking necessary data form existing one externally by measurement 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 stand Voltage (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 being brown glazed. 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: HV BCT: (i) 1st core: No of tapping: 4 1st 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: 4 1st 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: 4 1st 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 type with 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: 4 1st 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: 4 1st 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 brown porcelain. No CT required for the bushing. f. values of resistance reactance of the transformer shall not be deviated by more than 2% (two percent) of the BPDB’S requirements and the core & copper loss of transformer shall not exceed 5% (five percent) of BPDB’S requirements. The above-mentioned values are the tolerance values to be maintained during factory testing if exceeds 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 rated frequency and at 750C: 50MVA HV and MV winding = 271.712 KW 35MVA HV and LV winding = 170.854 KW 35MVA MV and LV winding = 130.092 KW g. 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 be chemically stable, free from acidity and other corrosive ingredients and shall posses high dielectric strength. Oil for first filling shall be shipped in non-returnable drums. 10% of the quantity required for a transformer is to be supplied in addition due to usual losses during installation centrifuging etc. i. The transformer tank shall be of welded construction fabricated from high tensile steel plate and 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 the conservator) 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 mounting separate MOLG. One part to be connected with transformer main tank through Buchholtz Relay (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 provided l. 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 of control 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 average ambient temperature of 400C. There shall be a control device in weather proof housing fitted on 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 which should 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 shall have two contacts among them one will be used for alarm circuit and other will be suitable 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) terminals shall have also connecting clamps appropriate for being connected with one 636 MCM ACSR conductor. The neutral terminal shall have connecting clamps to be connected with 2/0 HDBS wire. The size of conductors may be changed during approval stage. (viii) There shall be four wheels (flange type) suitable for mounting on rails and to carry 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 with appropriate paints of MUNSELL NO-5 Y7/1. Transformer with maximum shipping height (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 SCHEDULE OF 132/33/11KV POWER TRANSFORMER (To be filled up by the Bidder otherwise bid will be rejected) Sl. Description Unit BPDB’s Bidders No. Requirements Data 01. Name of Manufacturer 02. Type Out door 03. Rated Power (ONAN/ONAF) - High Voltage (HV) MVA 25/50 - Medium Voltage (MV) MVA 25/50 - Low Voltage (LV) MVA 18/35 04. Cooling system ONAN/ONAF 05. Phase 3- phase 06. Rated Voltage of Transformer - High Voltage winding kV 132 - Medium Voltage winding kV 33 - Low Voltage winding kV 11 07. Rated Frequency Hz 50 08. Maximum Temperature rise (Allowable over an ambient Temperature of 400C) - in Oil 0C 55 - in winding 0C 65 09. Total Excitation Current % 0.251 10. Core-loss at rated frequency and rated voltage at nominal tap kW 37.914 11. Full load copper loss at nominal voltage (HV-132kV, MV-33kv), at rated 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 130.092 12. Cooling fan losses during running At full ONAF capacity kW 13. Impedance Voltage for HV/MV at at 750C at 50MVA base (%) Tp 1 10.911 Tp 5 11.568 Tp 9 12.481 14. Impedance Voltage for HV/LV at at 750C at 35MVA base (%) Tp 1 18.500 Tp 5 19.443 Tp 9 20.796 15. Impedance Voltage for MV/LV at at 750C at 50MVA base (%) 6.051 16. Highest System Voltage - HV/MV/LV kV 145/36/12 17. Basic Insulation Level:- HV/MV/LV Lightning impulse voltage (1.2/50 kV 650/170/75 Peak µs wave) 18. Power Frequency Withstand Voltage (1 min) - HV/MV/LV kV 275/70/28 19. (a) HV winding resistance Y at 320C Tap1 1U-1N W 0.7500 1V-1N W 0.7625 1W-1N W 0.7500 Tap5 1U-1N W 0.6875 1V-1N W 0.6875 1W-1N W 0.6875 Tap9 1U-1N W 0.6275 1V-1N W 0.6275 1W-1N W 0.6275 (b) MV winding resistance Ж 2U-2N W 0.03625 2V-2N W 0.03625 2W-2N W 0.03625 (c)LV winding resistance For existing 1 3U-3W W 0.01100 3V-3U W 0.01125 3W-3V W 0.01125 20. 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 400 kV 650 21. Bucholz Relay - Manufacturer - Type 22. Vector Group Yn/Zn/D-1-11 23. BCT particulars: (a) HV side: - No of core in each bushing Nos 02 i. 1st core: No. of Tapping Nos 04 1st 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 Nos 04 1st tap 400/1A, class 0.2,20VA 2nd tap 600/1A, class0.2,30VA 3rd tap 750/1A, class 0.2,75VA 4th tap 1000/1A,class0.2,30VA (b) Neutral of HV side: - No of core Nos 02 1st core No. of Tapping Nos 04 1st 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 (c) MV side:3 No. of core in each busing Nos 02 i) 1st core: No. of Tapping Nos 04 1st 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 (d) Neutral of MV side: No. of core in each bushing Nos. 02 i) 1st core: No. of Tappin Nos. 04 1st 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) LV side No CT required 24. Weight: with Oil Kg without Oil Kg 25. Dimensions: Length x Width x Height mm 26. Dimension of rail As per BPDB’s existing Confirmed during detail Engineering.
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