TYPE TEST CERTIFICATE OF SHORT-CIRCUIT PERFORMANCE. A three-phase outdoor oil-immersed distribution transformer

Transcription

1 TYPE TEST CERTIFICATE OF SHORT-CIRCUIT PERFORMANCE APPARATUS A three-phase outdoor oil-immersed distribution transformer DESIGNATION 1000 kva SERIAL No Rated power Rated voltage Connection symbol Rated frequency 1000 kva 11 kv ± 2 x 2,5% / 433 V Dyn11 50 Hz MANUFACTURER TESTED FOR United Transformers Electric Co., Riyadh, Saudi Arabia United Transformers Electric Co., Riyadh, Saudi Arabia TESTED BY KEMA HIGH-POWER LABORATORY and HIGH-VOLTAGE LABORATORY Utrechtseweg AR Arnhem - The Netherlands DATE(S) OF TESTS 15 to 29 October 2008 The apparatus, constructed in accordance with the description, drawings and photographs incorporated in this Certificate, has been subjected to the series of proving tests in accordance with IEC This Type Test Certificate has been issued by KEMA following exclusively the STL Guides. The results are shown in the record of Proving Tests and the oscillograms attached hereto. The values obtained and the general performance are considered to comply with the above Standard with respect to the dynamic ability to withstand short-circuits. This Certificate applies only to the apparatus tested. The responsibility for conformity of any apparatus having the same designations with that tested rests with the Manufacturer. This Certificate consists of 40 sheets in total. This Certificate falls under the scope of the accreditation certificates L 020 and L 218 of the Dutch Council for Accreditation. See information sheet (page 2). Copyright: Only integral reproduction of this Certificate is permitted without written permission from KEMA. Electronic copies in e.g. PDF-format or scanned version of this Certificate may be available and have the status for information only. The sealed and bound version of the Certificate is the only valid version. KEMA Nederland B.V. P.G.A. Bus KEMA T&D Testing Services Managing Director Version: F Arnhem, 17 December 2008

2 INFORMATION SHEET Page 2 1 Certificate A Certificate contains a record of a series of type tests carried out strictly in accordance with a recognized standard. The equipment tested has fulfilled the requirements of this standard and the relevant ratings assigned by the manufacturer are endorsed by KEMA. The Certificate is applicable only to the equipment tested. KEMA is responsible for the validity and the contents of the Certificate. The responsibility for conformity of any apparatus having the same designation as the one tested rests with the manufacturer. The Certificate contains the essential drawings and a description of the equipment tested. Detailed rules are given in KEMA's Certification procedure. 2 Report of Performance A Report of Performance contains a record of one or more tests which have been carried out according to the client's instructions. These tests are not necessarily in accordance with a recognized standard. The test results do not verify ratings of the test object. KEMA issues three types of Reports of Performance: 2.1 The tests have been carried out strictly in accordance with. The apparatus has complied with the relevant requirements. This sentence will appear on the front page of a Report of Performance if the tests have been performed in accordance with a recognized standard, but the series of tests does not completely fulfil the requirements for a Certificate of Compliance (for example, if the number of test duties is not a complete series of type tests). The Report contains verified drawings and a description of the equipment tested. Detailed rules are given in KEMA's Certification procedure. The condition of the test object after the tests is assessed and recorded in the Report. 2.2 The tests have been carried out in accordance with the client's instructions. Test procedure and test parameters were based on... This sentence will appear on the front page of a Report of Performance if the number of tests, the test procedure and the test parameters are based on a recognized standard and related to the ratings assigned by the manufacturer. If the apparatus does not pass the tests such behaviour will be mentioned on the front sheet. Verification of the drawings (if submitted) and assessment of the condition after the tests is only done on the client's request. 2.3 The tests have been carried out according to the client's instructions. This sentence will appear on the front page of a Report of Performance if the tests, test procedure and/or test parameters are not in accordance with a recognized standard. 3 Standards When reference is made to a standard, and the date of issue is not stated, this applies to the latest issue, including amendments which have been officially published prior to the date of the tests. 4 Official and uncontrolled test documents The official test documents of KEMA High-Power Laboratory are issued in bound form. Uncontrolled copies may be provided as loose sheets or as a digital file for convenience of reproduction by the client. The copyright has to be respected at all times. 5 Accuracy of measurement In the table of test results the measured quantities are given in three digits. This method of presentation does not indicate an accuracy. The guaranteed uncertainty in the figures mentioned, taking into account the total measuring system, is less than 5%, unless mentioned otherwise. 6 Qualified by RvA (Dutch Council for Accreditation) KEMA High-Power Laboratory and High-Voltage Laboratory have been entered in the RvA-register for laboratories under resp. Nrs. L 020 and L 218 for the testing services as defined in the Field of Accreditation. The accreditation is carried out in accordance with ISO/IEC Version: M4 1

3 TABLE OF CONTENTS Page 3 TABLE OF CONTENTS: INFORMATION SHEET...2 IDENTIFICATION OF THE APPARATUS TESTED...4 Ratings assigned by the manufacturer...4 Description of apparatus tested...4 List of drawings...4 GENERAL INFORMATION...5 The tests were witnessed by...5 The tests were observed by...5 The transformer was inspected by...5 LEGEND...6 SUMMARY OF TESTS...7 REACTANCE MEASUREMENT OVERVIEW...9 DUTY: Routine tests before short-circuit tests...10 Tests DUTY: Short-circuit tests...15 Test circuit...16 Calculation sheet short-circuit current...17 Photograph before test...18 Tests to 6019, 6021 to 6023, 6025 to CONDITION AFTER TEST...28 Photograph after test...29 DUTY: Routine tests after short-circuit tests...30 Tests INSPECTION / CONCLUSION...35 Photographs during inspection...36 DRAWINGS...39 Version: G1 1

4 IDENTIFICATION OF THE APPARATUS TESTED Page 4 RATINGS/CHARACTERISTICS ASSIGNED BY THE MANUFACTURER Voltage 11 kv ± 2 x 2,5% / 433 V Power 1000 kva Current 52,5 / 1333 A Short-circuit impedance 5,67 % X Connection symbol Dyn11 Cooling method ONAN Frequency 50 Hz X Category I Apparent system power 500 MVA X = This rating has been proved by the tests of this Certificate. DESCRIPTION OF APPARATUS TESTED A three-phase outdoor oil-immersed distribution transformer LIST OF DRAWINGS The manufacturer has guaranteed that the equipment submitted for tests has been manufactured in accordance with the following drawings. KEMA has verified that these drawings adequately represent the equipment tested. The following drawings have been included in this Certificate: P11 Rev. B P Rev. 0 The following drawings are only listed for reference and are kept in KEMA s files: U11 Rev E Rev U12 Rev. A P Rev. A U81 Rev D00 Rev P11 Rev. A P Rev. B P Rev. A P Rev P Rev. A P Rev. A P Rev P Rev P Rev P Rev. A G Version: 1

5 GENERAL INFORMATION Page 5 THE TESTS WERE WITNESSED BY Name Abdul Hafeez, S. Company United Transformers Electric Co., Riyadh, Saudi Arabia THE TESTS WERE OBSERVED BY Name Bannink, H. Company KEMA High-Power Laboratory, Arnhem, The Netherlands Koevoets, R.C.A.M. Gruntjes, R.J.B. KEMA High-Voltage Laboratory, Arnhem, The Netherlands THE TRANSFORMER WAS INSPECTED BY Name Dobbe, N. Company KEMA High-Power Laboratory, Arnhem, The Netherlands Version: G3 1

6 LEGEND Page 6 PHASE INDICATIONS If more than one phase is recorded on oscillogram, the phases are indicated by the digits 1, 2 and 3. These phases 1, 2 and 3 correspond to the phase values in the columns of the accompanying table, respectively from left to right. EXPLANATION OF THE LETTER SYMBOLS AND ABBREVIATIONS ON THE OSCILLOGRAMS pu I1pri I1sec I2pri I2sec I3pri I3sec Itank U1S U2S U3S Uprot Per unit (the reference length of one unit is represented by the black bar on the oscillogram) Primary current transformer Secondary current transformer Primary current transformer Secondary current transformer Primary current transformer Secondary current transformer Tank current test object Supply voltage Supply voltage Supply voltage Protection signal Version: G4 1

7 SUMMARY: Short-circuit tests Page 7 Test no Tap position C kv 6,63 6,64 6,67 6,48 6,53 6,55 Voltage, phase value, beginning B kv 6,67 6,70 6,72 6,51 6,57 6,58 A kv 6,57 6,61 6,64 6,44 6,50 6,50 C kv 6,61 6,63 6,65 6,47 6,51 6,51 Voltage, phase value, end B kv 6,65 6,67 6,70 6,49 6,54 6,54 A kv 6,57 6,60 6,63 6,41 6,47 6,47 C A Current HV-winding, peak value B A A A C A Current HV-winding, phase value, beginning B A A A C A Current HV-winding, phase value, end B A A A C A Current HV-winding, phase value, average B A A A C ka 48,7-48,5 48,5 40,8-40,9 40,7 Current LV-winding, peak value B ka -36,1 35,7-36,9-49,1 49,1-49,6 A ka -42,2 42,1-41,5 37,0-37,5 38,1 C ka 20,7 20,7 20,8 21,3 21,5 21,5 Current LV-winding, phase value, beginning B ka 21,4 21,4 21,5 22,1 22,3 22,3 A ka 20,6 20,6 20,7 21,5 21,7 21,7 C ka 20,5 20,6 20,6 21,3 21,4 21,5 Current LV-winding, phase value, end B ka 21,2 21,3 21,4 22,0 22,1 22,1 A ka 20,6 20,7 20,7 21,4 21,5 21,5 C ka 20,6 20,7 20,7 21,3 21,4 21,5 Current LV-winding, phase value, average B ka 21,3 21,4 21,4 22,1 22,2 22,2 A ka 20,6 20,6 20,7 21,4 21,6 21,6 Current duration s 0,510 0,509 0,514 0,505 0,506 0,501 C Ω 16,59 16,65 16,68 14,95 14,99 14,99 Reactance after test B Ω 16,71 16,78 16,81 15,02 15,05 15,05 A Ω 16,62 16,65 16,68 14,89 14,92 14,92 REMARKS No visible disturbance. Reactances measured between resp. A-C, B-C, A-B. No visible disturbance. Reactances measured between resp. A-C, B-C, A-B. No visible disturbance. Reactances measured between resp. A-C, B-C, A-B. No visible disturbance. Reactances measured between resp. A-C, B-C, A-B. No visible disturbance. Reactances measured between resp. A-C, B-C, A-B. No visible disturbance. Reactances measured between resp. A-C, B-C, A-B. Version: 1

8 SUMMARY: Short-circuit tests Page 8 SUMMARY (continued) Test no Tap position C kv 5,95 5,96 5,96 Voltage, phase value, beginning B kv 6,00 6,00 6,00 A kv 5,92 5,92 5,91 C kv 5,95 5,94 5,94 Voltage, phase value, end B kv 5,98 5,99 5,99 A kv 5,91 5,91 5,92 C A Current HV-winding, peak value B A A A C A Current HV-winding, phase value, beginning B A A A C A Current HV-winding, phase value, end B A A A C A Current HV-winding, phase value, average B A A A C ka 39,1-39,1 39,5 Current LV-winding, peak value B ka 42,5-42,5 42,1 A ka -51,2 50,6-50,8 C ka 21,3 21,3 21,3 Current LV-winding, phase value, beginning B ka 21,8 21,8 21,9 A ka 21,3 21,2 21,3 C ka 21,2 21,2 21,3 Current LV-winding, phase value, end B ka 21,9 21,9 21,9 A ka 21,2 21,2 21,2 C ka 21,3 21,3 21,3 Current LV-winding, phase value, average B ka 21,8 21,8 21,8 A ka 21,3 21,2 21,3 Current duration s 0,510 0,500 0,513 C Ω 13,10 13,13 13,13 Reactance after test B Ω 13,16 13,16 13,16 A Ω 13,10 13,13 13,13 REMARKS No visible disturbance. Reactances measured between resp. A-C, B-C, A-B. No visible disturbance. Reactances measured between resp. A-C, B-C, A-B. No visible disturbance. Reactances measured between resp. A-C, B-C, A-B. Version: 1

9 REACTANCE MEASUREMENT OVERVIEW Page 9 Test number Measured between the phases Tap position 1 Reactance Calculated per leg Change per leg Ω Ω % A-C B-C A-B C B A C B A Before tests 16,52 16,43 16,37 24,91 24,63 24, AT ,59 16,71 16,62 24,80 25,18 24,90-0,4 2,2 1,9 AT ,65 16,78 16,65 24,91 25,29 24,91 0,0 2,7 1,9 AT ,68 16,81 16,68 24,96 25,34 24,96 0,2 2,9 2,1 After tests 16,87 16,90 16,87 25,29 25,38 25,29 1,5 3,1 3,5 Test number Measured between the phases Tap position 3 Reactance Calculated per leg Change per leg Ω Ω % A-C B-C A-B C B A C B A Before tests 14,55 14,64 14,58 21,76 22,04 21, AT ,95 15,02 14,89 22,43 22,62 22,24 3,1 2,6 1,8 AT ,99 15,05 14,92 22,48 22,67 22,29 3,3 2,9 2,0 AT ,99 15,05 14,92 22,48 22,67 22,29 3,3 2,9 2,0 After tests 15,05 15,08 15,02 22,57 22,67 22,48 3,8 2,8 2,9 Test number Measured between the phases Tap position 5 Reactance Calculated per leg Change per leg Ω Ω % A-C B-C A-B C B A C B A Before tests 12,69 12,79 12,75 18,96 19,24 19, AT ,10 13,16 13,10 19,62 19,81 19,62 3,5 2,9 2,5 AT ,13 13,16 13,13 19,68 19,78 19,68 3,8 2,8 2,8 AT ,13 13,16 13,13 19,68 19,78 19,68 3,8 2,8 2,8 After tests 13,13 13,16 13,13 19,68 19,78 19,68 3,8 2,8 2,8 MAXIMUM DEVIATION The maximum deviation in reactance per leg was 3,8%. The maximum deviation allowed in accordance with the IEC is 7,5%. Version: M2 D1 1

10 DUTY: Routine tests before short-circuit tests Page 10 Standard and date Standard IEC , clause Test date Transformer in same condition. Environmental conditions Ambient temperature 21 C Ambient air pressure 1013 hpa Temperature of test object 20,6 C Humidity 12 g/m 3 MEASUREMENT OF WINDING RESISTANCE DC-winding resistances at 20,6 C HV winding (Ω) LV winding (mω) Terminals Tap position Terminals A8-B8 1,106 1,047 0,989 a2-b2 1,364 A8-C8 1,107 1,048 0,990 a2-c2 1,383 B8-C8 1,105 1,046 0,989 b2-c2 1,363 Average 1,106 1,047 0,989 Average 1,370 Requirements None. Result The results are used for further calculations and are for information only. Version: M4 1

11 Routine tests before short-circuit tests Page 11 MEASUREMENT OF VOLTAGE RATIO AND CHECK OF PHASE DISPLACEMENT Ratio for Dyn11 Tap position Declared ratio 46,20 44,00 41,80 Phase 1 46,23 44,02 41,81 Phase 2 46,23 44,02 41,81 Phase 3 46,23 44,02 41,81 Average 46,23 44,02 41,81 Deviation from declared ratio (%) -0,06-0,04-0,02 Requirements None. Result The results are used for further calculations and are for information only. Version: 1

12 Routine tests before short-circuit tests Page 12 MEASUREMENT OF SHORT-CIRCUIT IMPEDANCE AND LOAD LOSS Load loss and characteristics at θ ref of 75 C Tap position Load-losses (W) R K (Ω) 1,39 1,28 1,18 U R (%) 1,04 1,06 1,08 X K (Ω) 8,12 7,23 6,30 U X (%) 6,08 5,97 5,77 Z K (Ω) 8,23 7,34 6,41 U K (%) 6,17 6,07 5,87 Requirements None. Results The results are used for further calculations and are for information only. Version: 1

13 Routine tests before short-circuit tests Page 13 MEASUREMENT OF NO-LOAD LOSS AND CURRENT No-load losses and currents in tap position 3 Terminal U rms U mean I I/I n x 100 P P o (V) (V) (A) (%) (W) (W) a2 436,5 433,6 4,12 0, b2 434,3 433,3 3,40 0, c2 435,1 432,8 4,28 0, Average 435,3 433,2 3,93 0,29 Total Note: The no-load losses are calculated with the formula U P0 = P 1 + U U mean mean RMS Requirements None. Results The results are used for further calculations and are for information only. Version: 1

14 Routine tests before short-circuit tests Page 14 DIELECTRIC ROUTINE TESTS Separate source AC withstand voltage test (applied voltage test) Tap position Winding Applied voltage Duration Frequency 3 (kv) (min) (Hz) HV LV Requirements No collapse of the test voltage shall occur. Result The tests are passed. INDUCED AC VOLTAGE TESTS (ACSD) Tap position Winding Induced voltage phase-to-phase Duration Frequency (V) (min) (Hz) 3 LV Requirements No collapse of the test voltage shall occur. Result The test is passed. Version: 1

15 DUTY: Short-circuit tests Page 15 TEST NUMBERS CONDITION BEFORE TESTS Transformer in same condition. Supply to HV winding by means of flexible connections. LV winding short-circuited by means of shunts and earthed. Tank earthed via an earth fault current indicating CT. Version: M4 D1 1

16 Test circuit for Short-circuit tests Page 16 TEST-CIRCUIT S01 G MB MS L PT TO U U U Ι Ι Ι Ι Ι Ι Ι U Ι G = Generator TO = Test Object U = Voltage Measurement to earth MB = Master Breaker L = Reactor Ι = Current Measurement MS = Make Switch PT = Power Transformer Supply Power MVA 500 Frequency Hz 50 Phase(s) 3 Voltage kv 11 Current ka 26,24 Impedance Ω 0,242 Power factor < 0,1 Neutral not earthed Load Short-circuit point earthed Version: C1 1 Remarks: -

17 Calculation sheet short-circuit current for Short-circuit tests Page 17 System power of : 500 MVA System voltage of: 11 kv tap position 1 Max. 3 Nom. 5 Min. tap voltage 11,55 kv 11,00 kv 10,45 kv impedance voltage % 6,17 % 6,07 % 5,87 % resistance % (75 C) 1,04 % 1,06 % 1,08 % TAP POSITION 1 Max. Supply voltage: 11,55 kv Terminal voltage: 11,55 kv Short cir. current min. value rated max. value HV current 728,9 A 809,9 A 890,8 A LV current 19,44 ka 21,60 ka 23,76 ka LV peak current 46,25 ka 48,68 ka 51,12 ka HV reactance: 8,12 Ω HV inductance: 25,84 mh TAP POSITION 3 Nom. Supply voltage: 11,00 kv Terminal voltage: 11,00 kv Short cir. current min. value rated max. value HV current 778,9 A 865,4 A 951,9 A LV current 19,79 ka 21,98 ka 24,18 ka LV peak current 46,71 ka 49,17 ka 51,63 ka HV reactance: 7,23 Ω HV inductance: 23,00 mh TAP POSITION 5 Min. Supply voltage: 10,45 kv Terminal voltage: 10,45 kv Short cir. current min. value rated max. value HV current 847,3 A 941,5 A 1035,6 A LV current 20,45 ka 22,72 ka 24,99 ka LV peak current 47,79 ka 50,31 ka 52,82 ka HV reactance: 6,30 Ω HV inductance: 20,05 mh peakfactor according to IEC = 2,24 Zsupply / Ztrafo = 3,30 % peakfactor according to X/R = 2,24 Version: M2 1

18 Photograph before test Page 18 P1-BT Version: 1

19 Short-circuit test Page 19 Uprot 20.1kV pu 6017 U1S 38.6kV pu I1pri 5.01kA pu I1sec 125kA pu U2S 38.6kV pu I2pri 5.01kA pu I2sec 125kA pu U3S 38.6kV pu I3pri 5.01kA pu I3sec 125kA pu Itank 5.01kA pu unit 1.00 s TEST NUMBER: Phase C B A Tap position 1 Voltage, phase value, beginning kv 6,63 6,67 6,57 Voltage, phase value, end kv 6,61 6,65 6,57 Current HV-winding, peak value A Current HV-winding, phase value, beginning A Current HV-winding, phase value, end A Current HV-winding, phase value, average A Current LV-winding, peak value ka 48,7-36,1-42,2 Current LV-winding, phase value, beginning ka 20,7 21,4 20,6 Current LV-winding, phase value, end ka 20,5 21,2 20,6 Current LV-winding, phase value, average ka 20,6 21,3 20,6 Current duration s 0,510 Reactance after test Ω 16,59 16,71 16,62 Remarks: No visible disturbance. Reactances measured between resp. A-C, B-C, A-B. Version: T41 1

20 Short-circuit test Page 20 Uprot 20.1kV pu 6018 U1S 38.6kV pu I1pri 5.01kA pu I1sec 125kA pu U2S 38.6kV pu I2pri 5.01kA pu I2sec 125kA pu U3S 38.6kV pu I3pri 5.01kA pu I3sec 125kA pu Itank 5.01kA pu unit 1.00 s TEST NUMBER: Phase C B A Tap position 1 Voltage, phase value, beginning kv 6,64 6,70 6,61 Voltage, phase value, end kv 6,63 6,67 6,60 Current HV-winding, peak value A Current HV-winding, phase value, beginning A Current HV-winding, phase value, end A Current HV-winding, phase value, average A Current LV-winding, peak value ka -48,5 35,7 42,1 Current LV-winding, phase value, beginning ka 20,7 21,4 20,6 Current LV-winding, phase value, end ka 20,6 21,3 20,7 Current LV-winding, phase value, average ka 20,7 21,4 20,6 Current duration s 0,509 Reactance after test Ω 16,65 16,78 16,65 Remarks: No visible disturbance. Reactances measured between resp. A-C, B-C, A-B. Version: T41 1

21 Short-circuit test Page 21 Uprot 20.1kV pu 6019 U1S 38.6kV pu I1pri 5.01kA pu I1sec 125kA pu U2S 38.6kV pu I2pri 5.01kA pu I2sec 125kA pu U3S 38.6kV pu I3pri 5.01kA pu I3sec 125kA pu Itank 5.01kA pu unit 1.00 s TEST NUMBER: Phase C B A Tap position 1 Voltage, phase value, beginning kv 6,67 6,72 6,64 Voltage, phase value, end kv 6,65 6,70 6,63 Current HV-winding, peak value A Current HV-winding, phase value, beginning A Current HV-winding, phase value, end A Current HV-winding, phase value, average A Current LV-winding, peak value ka 48,5-36,9-41,5 Current LV-winding, phase value, beginning ka 20,8 21,5 20,7 Current LV-winding, phase value, end ka 20,6 21,4 20,7 Current LV-winding, phase value, average ka 20,7 21,4 20,7 Current duration s 0,514 Reactance after test Ω 16,68 16,81 16,68 Remarks: No visible disturbance. Reactances measured between resp. A-C, B-C, A-B. Version: T41 1

22 Short-circuit test Page 22 Uprot 20.1kV pu 6021 U1S 38.6kV pu I1pri 5.01kA pu I1sec 125kA pu U2S 38.6kV pu I2pri 5.01kA pu I2sec 125kA pu U3S 38.6kV pu I3pri 5.01kA pu I3sec 125kA pu Itank 5.01kA pu unit 1.00 s TEST NUMBER: Phase C B A Tap position 3 Voltage, phase value, beginning kv 6,48 6,51 6,44 Voltage, phase value, end kv 6,47 6,49 6,41 Current HV-winding, peak value A Current HV-winding, phase value, beginning A Current HV-winding, phase value, end A Current HV-winding, phase value, average A Current LV-winding, peak value ka 40,8-49,1 37,0 Current LV-winding, phase value, beginning ka 21,3 22,1 21,5 Current LV-winding, phase value, end ka 21,3 22,0 21,4 Current LV-winding, phase value, average ka 21,3 22,1 21,4 Current duration s 0,505 Reactance after test Ω 14,95 15,02 14,89 Remarks: No visible disturbance. Reactances measured between resp. A-C, B-C, A-B. Version: T41 1

23 Short-circuit test Page 23 Uprot 20.1kV pu 6022 U1S 38.6kV pu I1pri 5.01kA pu I1sec 125kA pu U2S 38.6kV pu I2pri 5.01kA pu I2sec 125kA pu U3S 38.6kV pu I3pri 5.01kA pu I3sec 125kA pu Itank 5.01kA pu unit 1.00 s TEST NUMBER: Phase C B A Tap position 3 Voltage, phase value, beginning kv 6,53 6,57 6,50 Voltage, phase value, end kv 6,51 6,54 6,47 Current HV-winding, peak value A Current HV-winding, phase value, beginning A Current HV-winding, phase value, end A Current HV-winding, phase value, average A Current LV-winding, peak value ka -40,9 49,1-37,5 Current LV-winding, phase value, beginning ka 21,5 22,3 21,7 Current LV-winding, phase value, end ka 21,4 22,1 21,5 Current LV-winding, phase value, average ka 21,4 22,2 21,6 Current duration s 0,506 Reactance after test Ω 14,99 15,05 14,92 Remarks: No visible disturbance. Reactances measured between resp. A-C, B-C, A-B. Version: T41 1

24 Short-circuit test Page 24 Uprot 20.1kV pu 6023 U1S 38.6kV pu I1pri 5.01kA pu I1sec 125kA pu U2S 38.6kV pu I2pri 5.01kA pu I2sec 125kA pu U3S 38.6kV pu I3pri 5.01kA pu I3sec 125kA pu Itank 5.01kA pu unit 1.00 s TEST NUMBER: Phase C B A Tap position 3 Voltage, phase value, beginning kv 6,55 6,58 6,50 Voltage, phase value, end kv 6,51 6,54 6,47 Current HV-winding, peak value A Current HV-winding, phase value, beginning A Current HV-winding, phase value, end A Current HV-winding, phase value, average A Current LV-winding, peak value ka 40,7-49,6 38,1 Current LV-winding, phase value, beginning ka 21,5 22,3 21,7 Current LV-winding, phase value, end ka 21,5 22,1 21,5 Current LV-winding, phase value, average ka 21,5 22,2 21,6 Current duration s 0,501 Reactance after test Ω 14,99 15,05 14,92 Remarks: No visible disturbance. Reactances measured between resp. A-C, B-C, A-B. Version: T41 1

25 Short-circuit test Page 25 Uprot 20.1kV pu 6025 U1S 38.6kV pu I1pri 5.01kA pu I1sec 125kA pu U2S 38.6kV pu I2pri 5.01kA pu I2sec 125kA pu U3S 38.6kV pu I3pri 5.01kA pu I3sec 125kA pu Itank 5.01kA pu unit 1.00 s TEST NUMBER: Phase C B A Tap position 5 Voltage, phase value, beginning kv 5,95 6,00 5,92 Voltage, phase value, end kv 5,95 5,98 5,91 Current HV-winding, peak value A Current HV-winding, phase value, beginning A Current HV-winding, phase value, end A Current HV-winding, phase value, average A Current LV-winding, peak value ka 39,1 42,5-51,2 Current LV-winding, phase value, beginning ka 21,3 21,8 21,3 Current LV-winding, phase value, end ka 21,2 21,9 21,2 Current LV-winding, phase value, average ka 21,3 21,8 21,3 Current duration s 0,510 Reactance after test Ω 13,10 13,16 13,10 Remarks: No visible disturbance. Reactances measured between resp. A-C, B-C, A-B. Version: T41 1

26 Short-circuit test Page 26 Uprot 20.1kV pu 6026 U1S 38.6kV pu I1pri 5.01kA pu I1sec 125kA pu U2S 38.6kV pu I2pri 5.01kA pu I2sec 125kA pu U3S 38.6kV pu I3pri 5.01kA pu I3sec 125kA pu Itank 5.01kA pu unit 1.00 s TEST NUMBER: Phase C B A Tap position 5 Voltage, phase value, beginning kv 5,96 6,00 5,92 Voltage, phase value, end kv 5,94 5,99 5,91 Current HV-winding, peak value A Current HV-winding, phase value, beginning A Current HV-winding, phase value, end A Current HV-winding, phase value, average A Current LV-winding, peak value ka -39,1-42,5 50,6 Current LV-winding, phase value, beginning ka 21,3 21,8 21,2 Current LV-winding, phase value, end ka 21,2 21,9 21,2 Current LV-winding, phase value, average ka 21,3 21,8 21,2 Current duration s 0,500 Reactance after test Ω 13,13 13,16 13,13 Remarks: No visible disturbance. Reactances measured between resp. A-C, B-C, A-B. Version: T41 1

27 Short-circuit test Page 27 Uprot 20.1kV pu 6027 U1S 38.6kV pu I1pri 5.01kA pu I1sec 125kA pu U2S 38.6kV pu I2pri 5.01kA pu I2sec 125kA pu U3S 38.6kV pu I3pri 5.01kA pu I3sec 125kA pu Itank 5.01kA pu unit 1.00 s TEST NUMBER: Phase C B A Tap position 5 Voltage, phase value, beginning kv 5,96 6,00 5,91 Voltage, phase value, end kv 5,94 5,99 5,92 Current HV-winding, peak value A Current HV-winding, phase value, beginning A Current HV-winding, phase value, end A Current HV-winding, phase value, average A Current LV-winding, peak value ka 39,5 42,1-50,8 Current LV-winding, phase value, beginning ka 21,3 21,9 21,3 Current LV-winding, phase value, end ka 21,3 21,9 21,2 Current LV-winding, phase value, average ka 21,3 21,8 21,3 Current duration s 0,513 Reactance after test Ω 13,13 13,16 13,13 Remarks: No visible disturbance. Reactances measured between resp. A-C, B-C, A-B. Version: T41 1

28 CONDITION AFTER TEST Page 28 CONDITION AFTER TEST Externally no visible change. Version: D3 1

29 Photograph after test Page 29 P1-AT Version: 1

30 DUTY: Routine tests after short-circuit tests Page 30 Standard and date Standard IEC , clause Test date Transformer in same condition. Environmental conditions Ambient temperature 20 C Ambient air pressure 1004 hpa Temperature of test object 19,6 C Humidity 7 g/m 3 MEASUREMENT OF WINDING RESISTANCE DC-winding resistances at 19,6 C HV winding (Ω) LV winding (mω) Terminals Tap position Terminals A8-B8 1,096 1,039 0,981 a2-b2 1,347 A8-C8 1,098 1,040 0,982 a2-c2 1,373 B8-C8 1,096 1,039 0,981 b2-c2 1,357 Average 1,097 1,039 0,981 Average 1,359 Requirements None. Result The results are used for further calculations and are for information only. Version: M4 1

31 Routine tests after short-circuit tests Page 31 MEASUREMENT OF VOLTAGE RATIO AND CHECK OF PHASE DISPLACEMENT Ratio for Dyn11 Tap position Declared ratio 46,20 44,00 41,80 Phase 1 46,23 44,02 41,80 Phase 2 46,23 44,02 41,80 Phase 3 46,23 44,02 41,80 Average 46,23 44,02 41,80 Deviation from declared ratio (%) -0,06-0,04 0,00 Requirements None. Result The results are used for further calculations and are for information only. Version: 1

32 Routine tests after short-circuit tests Page 32 MEASUREMENT OF SHORT-CIRCUIT IMPEDANCE AND LOAD LOSS Load loss and characteristics at θ ref of 75 C Tap position Load-losses (W) R K (Ω) 1,38 1,28 1,17 U R (%) 1,03 1,06 1,08 X K (Ω) 8,34 7,44 6,49 U X (%) 6,25 6,15 5,94 Z K (Ω) 8,45 7,55 6,59 U K (%) 6,34 6,24 6,04 Requirements None. Results The results are used for further calculations and are for information only. Version: 1

33 Routine tests after short-circuit tests Page 33 MEASUREMENT OF NO-LOAD LOSS AND CURRENT No-load losses and currents in tap position 3 Terminal U rms U mean I I/I n x 100 P P o (V) (V) (A) (%) (W) (W) a2 435,2 432,7 4,18 0, b2 434,5 433,5 3,39 0, c2 435,3 432,9 4,08 0, Average 435,0 433,0 3,88 0,29 Total Note: The no-load losses are calculated with the formula U P0 = P 1 + U U mean mean RMS Requirements None. Results The results are used for further calculations and are for information only. Version: 1

34 Routine tests after short-circuit tests Page 34 DIELECTRIC ROUTINE TESTS Separate source AC withstand voltage test (applied voltage test) Tap position Winding Applied voltage Duration Frequency 5 (kv) (min) (Hz) HV LV Requirements No collapse of the test voltage shall occur. Result The tests are passed. INDUCED AC VOLTAGE TESTS (ACSD) Tap position Winding Induced voltage phase-to-phase Duration Frequency (V) (min) (Hz) 1 LV Requirements No collapse of the test voltage shall occur. Result The test is passed. Version: 1

35 INSPECTION / CONCLUSION Page 35 INSPECTION OF THE ACTIVE PART On 29 October 2008 the transformer was untanked and the active part was inspected. The out-of-tank inspection with respect to displacements, deformations of core and windings, connections and supporting structures or traces of discharges did not reveal any apparent defects. CONCLUSION The transformer complies with IEC (Ability to withstand short-circuit), subclause Version: 1

36 Photograph during inspection Page 36 P1-GE Version: 1

37 Photograph during inspection Page 37 P1-GE Version: 1

38 Photograph during inspection Page 38 P1-GE Version: 1

39 Drawing Page 39 Version: DR 1

40 Drawing Page 40 Version: DR 1