इंटरनेट मानक Disclosure to Promote the Right To Information Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public. “जान1 का अ+धकार, जी1 का अ+धकार” “प0रा1 को छोड न’ 5 तरफ” Mazdoor Kisan Shakti Sangathan Jawaharlal Nehru “The Right to Information, The Right to Live” “Step Out From the Old to the New” IS 14902-1 (2001): Performance of High-Voltage D.C. (HVDC) Systems, Part 1: Steady State Conditions [ETD 40: HVDC Power Systems] “!ान $ एक न’ भारत का +नम-ण” Satyanarayan Gangaram Pitroda ““IInnvveenntt aa NNeeww IInnddiiaa UUssiinngg KKnnoowwlleeddggee”” “!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता हहहहै””ै” Bhartṛhari—Nītiśatakam “Knowledge is such a treasure which cannot be stolen” IS 14902( Part 1 ) : 2001 IEC 60919-1 ( 1988 ) W’?mm a.#r. G=fdrR!m (q=Ldr.a.#L)wll-ar&l c n lLIC#IIIYCIT *m” ‘JTFr13mR’mf131mQn Indian Standard PERFORMANCE OF HIGH-VOLTAGE HVDC ) d.C. ( SYSTEMS PART 1 STEADY STATE CONDITIONS ICS 29.200:29.240.99 0 BIS 2001 BUREAU OF INDIAN STANDARDS MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG NEW DELHI 110002 January 2001 Price Group 15 IS 14902( Part 1) :2001 IEC 60919-1( 1988) High VoltageDirect Current Power Systems Sectional Committee, ET 40 NATIONALFOREWORD This standard (Part 1)which isidentical with IEC 60919-1 (1988) ‘Performance ofhigh-voltage d.c. (HVDC) systems — Part 1 :Steady-state conditions’ issued bythe International Electrotechnical Commission (IEC), was adopted by the Bureau ofIndian Standards onthe recommendation ofHigh VoltageDirect Current Power Systems Sectional Committee (ET 40) and approval ofthe Electrotechnical Division Council. This International Standard is one ofthe series, which deals with performance of HVDC systems. The No. ofthis IEC Publication [which wasearlier IEC 919-1(1988)] stands redesignated byIEC asmentioned above. The series comprises ofthe following IEC standards: Publication No.- Tltle IEC60919-1( 1988) Performance ofHVDC systems — Part 1:Steady-state conditions tEC60919-2( 1990) Performance ofHVDC systems — Part 2:Faults and switching IEC60919-3( 1999) Performance ofHVDC systems— Part 3:Dynamic conditions This standard (Part 1)being identical with IEC 60919-1, the other parts ofthis Indian Standard aligning with other parts of IEC 60919 will be taken up in due course. Certain conventions are, however, not identical to those used in the Indian Standards. Attention is drawn particularly to the following: a) Wherever the words ‘International Standard’ appear referring tothis standard, they should be read as Indian Standard, and b) Comma ( ,) has been used as the decimal marker while in Indian Standards, the current practice isto use apoint ( .)asa decimal marker. Only the English text ofthe IEC publication has been retained while adopting it as Indian Standard, and as such the page numbers given her e are not same asin IEC publication. The two digits, three digits and fou r digits IEC publication No.(s) stand redesignated byprefix 600, 60 and 6respectively; for example IEC 99-1 and IEC 605-1 stand redesignated as IEC 60099-1 and IEC 60605-2 and IEC 1071-1 stand redesignated as IEC 61071-1 respectively. CROSSREFERENCES Inthis adopted Indian Standard, reference appearstocertain Internatioml Standards forwhich Indian Standards also exist. The corresponding Indian Standard which are tobe substituted in their respective places are listed along with the latest IEC Publications, besides giving the degree ofequivalence: IEC Pub No. Latest IEC Title of the Latest Correspond- Title of Indian Degree of with Year Pub No. IEC Publication ing Indian Standard Equivalence Referred to with Year Standard 50(11): 1956 60050-551 International Electro- 1885 Electrotechnical Identical to superseded by 50 (1998) technical Vocabulary (Part 27): vocabulary: Part 27 IEc 60050 (551 )( 1982) — Part 551 : Power 1993 Power electronics (551)(1982) electronics 50(37): 1%6 60050-351 International Electro- 1885 Electrotechnical Identical to superseded by (1998) technical Vocabulary (Pati75): vocabulary :Part 75 IEC60050 50 (351) (1975) —Part351 :Automatic 1993 Automatic control (351)(1975) control (i) IS 14902 (Part 1) :2001 lEC 60919-1( 1988) lb:(”’Pub No, Latest IEC Title of the Latest Correspond- Title of Indian Degree of with lkar Pub No. IEC Publication ing Indian Standard Equivalence Referred to with Year Standard 50(131):1978 60050-131 International Electro- 1885 Electrotechnical Identical (1978) technical Vocabulary (Rut 57): vocabulary :Part 57 — Electrical and 1993 Electrical and ‘magneticcircuit magnetic circuit 50(441):1984 60050-441” International Electro- 1885 Electrotechnical Not (1984) technical Vocabulary (IM 17): vocabulary :Part 17 equivalent — Switchgear control- 1979 Switchgear control- gear and fuses gear 50(601):1985 60050601 International Electro- 1885 Electrotechnical Identical (1985) technical Vocabulary (Rat 78) : vocabulary: Part 78 — Chapter 601 : 1993 Generation transmi- Generation transmis- ssion and distribu- sion and distribution tion of electricity — ofelectricity—general General 50(602):(1983) 60950602 International Electro- 1885 Electrotechnical do (1983) technical Vocabulary (Part69) : vocabulary: Part 69 — Chapter 601 : 1993 Generation transmi- Generation transmis- ssion and distribu- sionanddistribution of tion of electricity — electricity generation Generation 50(603):(1986) 60050603 International Electro- IS1885 Electrotechnical do (1986) technical Vocabulary (Part79) : vocabulary: Part 79 — Chapter 603 : 1993 CJeneratlon,transmi- Generallon, transmits- ssion and distribu- ion and distribution tion of electricity ofelectricity —Power — Power system system planning and planning and management management 50(605):(1983) 6005W505 International Electro- IS1885 Electrotechnical do (1983) technical Vocabulary (Part71) : vocabulary :Part 71 —Generation transmi- 1993 Generation transmi- ssion and distribution ssion and distribu- of electricity — Sub- tion of electricity stations — Substations 50(902): (1973) 60050-161 International Electro- IS1885 Electrotechnical Not (1990) technicai Vocabulary (Part 64/See 1 vocabulary :Part 64 equivalent — Chapter 161 : and Sec2) : Electromagnetic Electromagnetic com- 1987 compatibility, patibility Section 1 General and Section 2 Specific terms 76-4(1976) 60076-1 Power transformers IS2026 Powertransformers: “ do (1993) —Part 1: General (Part4): 1977 Part 4 Terminal correspond- markings, tappings ing to IEC and connections 60076-4(1976) 99-1(1970) 60(W-1 Surge arrestors — IS3071 Lighlnmg arrestor do (1991) Part 1 : Non-linear (Part 1): 1985 for alternating (ii) IS 14902( Part 1) :2001 IEC 60919-1( 1986) IEC Pub No. Latest IEC Title of the Latest Correspond- Title of Indian Degree of with Year Pub No. IEC Publication ing Indian Standard Equivalence Referred to with Year Standard type gapped arrestors correspond- current systems : for ac systems ing to IEC Part 1 Non-linear 60099-1 resistor type light- (1970) ning arrestors 117(1966) 60617-1 Graphical symbols for IS12032 Graphical symbols Identical to superseded by (1985) diagrams — Part 1 : (Rut 1): 1987 fordiagrams :Part 1 IEC60617-1 IEC617(1985) General information, General information, (1985) general index, cross general index, cross references and tables references and tables 146 (1973) 60146-1-1 Semiconductor con- No 1SS — — (1991) and vertors – Part 1– 1 : 60146-1-2 Basic requirements (1991) and Part 1-2Applica- tion guide 146-4(1986) 62040-3 Semiconductor con- No 1SS — — (1999) vertors – Part 4 : Method of specifying the performance and testing requirements of unintemlpted power systems 147(1966) 6074’7-5-2 Discretesemiconductor 3700 (Partl) Essentialratings and Not (1997) and devicesandintegrated :1972 and characteristics of equivalent 60747-5-3 circuits — Part 5-2 : IS4400(Partl) semiconductor (1997) Optoelectronics :1967—Both devices : Part 1 devices — Essential correspond- Generalandmethods ratings and charac- ingtoIEC147 of measurements teristics and Part 5-3: (1966) on semiconductor Measuring methods devices 148 1969) 60748-1( 984) Semiconductordevices 1885 Electrotechnical do andintegrated circuits (Part7/See1): vocabulary : Part 7 —Part 1: General 1972 Semiconductor devices, Section 1 General 214(1976) 60214 (1989) On-load tap-changers 8468:1977 On-load tap- do changers 271(1974) 60050-191 International Electro- 1885 Electrotechnical do (1990) technical Vocabulary (Part39) : vocabulary: Part 39 — Part 191: Depend- 1979 Reliability of elect- ability and quality of ronic and electrical service items 272(1968) 60300-1 Dependability manage- No1SS — — superseded by (1993) ment—Part 1:Depend- IEC(300)(1984) ability management programme 300(1984) 60300(1993) Dependability manage- No1SS — in parts ment — Inparts (iii ) IS 14902 (Part 1) :2001 IEC 60919-1( 1988) IEC Pub No. Latest IEC Title of the Latest Correspond- Title of Indian Degree of with Year Pub No. LEC Publication ing Indian Standard Equivalence Referred to with Year Standard 354(1972) 60354 (1991) Loading guide for oil- 6600:1972 Guide for loading Not immersed power trans- correspond- oil-immersed power equivalent formers ing to IEC transformers 354(1972) 542(1976) 60542 (1976) Application guide for 8478:1977 Application guide do on-load tap-changers for on-load tap- changers 551(1976) 60551 (1987) Determination of 13964:1994 Methodsofmeasure- do transformer and ment of transformer reactor sound levels and reactor sound levels 605-1(1978) 60605-1(1978) Equipment reliability 8161 Guideforequipment Identical to testing : Part 1 — (Part 1):1999 reliability testing : EC 60605-1 General requirements Part 1 Principles (1978) and procedures 606(1978) 60076-1 Powertransformers— 2026 Powertransformers: Not (1993) Part 1: General (Rut 1)1977 Part 1General equivalent 617(1985) 60617-1(1985) Graphical symbols for 12032 Graphical symbols Identical diagrams — Part 1 : (part 1): 1987 for diagrams :Part 1 General information, Generalinformation, generalindex—Cross- generalindex– Cross -referencetables reference tables 633(1978) 60633 (1998) Terminology for high- 14801:2000 Terminology for Identical to voltage direct current high-voltage direct IEC60633 (1-IVDC)transmission current (1-rVDc) (1998) transmission 651(1979) 60651 (197 9) Sound level meters 9779:1981 Sound-level meters Identical 700(“981) 60700- (1998) Thyristor valves for 14911 Thyristor valves for Identical to EC high-voltage direct (Part1):2001 high-voltage direct 60700-1 current (HVDc) current (I-IvDC) (1998) transmission – Part 1: powertransmission : Electrical testing Part 1 Electrical testing For the purpose ofdeciding whether aparticular requirement ofthis standard iscomplied with, the finaI value, observed or calculated, expressing the result of a~est, shall be rounded off in ac~ordance with IS 2: 1960 ‘Rulesfor rounding offnumerical values (revised)’. The number ofsignificant places retained in the rounded offvalue should be the same as that ofthe specified value in this standard. (iv) IS 14902 (Part 1) :2001 IEC 60919-1 ( 1988) Page clause SECTION ONE – GENERAL I. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. ReferencetootheclECpublications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 SECTION TWO – OUTLINE OF ST’EADY-ST.ATEHVDC SYSTEM PERFORMANCE SPECIFICATION 3. Steady-stateperformancespecification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 SECTION THREE – TYPES OF HVDC SYSTEMS 4. General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5. HVDCback-to-backties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6. MonopolarearthreturnHVDCsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 7. MonopolarmetallicreturnHVDCsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 8. BipolarHVDCsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 9. Bipolarmetallicneutralsystem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 10.Two12-pulsegroupsperpole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 11.Convertortransformerarrangements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 12.D.C.switchingconsiderations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 SECTION FOUR – ENVIRONMENT 13.1nformationtobesupplied. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SECTIONFIVE-- RATED POWER,CURRENT AND VOLrA~E 14.Ratedpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 15.Ratedcurrent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 16.Ratedvoltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 SECTION SIX – OVERLOAD AND EQUIPMENT CAPABILITY 17. Overload . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 18. Equipmentcapability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 SECTION SEvEN – MI NIhIUM POWERTRANsFER ANDNO-LOADSTAND-D’STATE 19. General, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 20. Minimumcurrent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 21. Reduceddirectvoltageoperation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 22. No-loadstand-bystate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 SECTION EIGHT – A.C. SYSTEM 23. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 24. A.C.voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 25. Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 26. Systemimpedanceatfundamental frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 27. Systemimpedanceatharmonicfrequencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 28. Positiveandzerosequencesurgeimpedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 29. Othersourcesofharmonics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 30. Subsynchronousresonance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 SECTION NINE - REACTIVE POWER 31. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 32. Convertorreactivepowerconsumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 33. Reactivepowerbalancewiththea.c. system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 34. Reactivepowersupply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 35. Maximumsizeofswitchablevarbanks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 SECTION TEN – D.C. LINE. ELECTRODE LINE AND EARTH ELECTRODE / 36. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 37. Overheadline(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 1 IS 14902 (Part 1) :2001 IEC 60919-1 ( 1988) clause Page 38. Cable line(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 39. Electrodeline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 40. Earthelectrode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 SECIION ELWEN – RELIABILITY 41. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . . . . . . . . . 26 42. outage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 43. Periodhours(PH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 44. Base-powerlevel(P~) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 45. Energyunavailability(EU).. . . . . . . . . . . . . . . . . . . . . . . . . . . 27 46. Energyavailability(E,4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 47. Maximumpermittednumberofforced outages, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 48. Statisticalprobabilityofoutages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 SECrION TwEJ. v~– CONTROL AND METERING 49. Controlobjectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 50. Controlstructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 5i. Controlordersettings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 52. C’urrentlimits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 53. Controlcircuitredundancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 54. Metering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 SECTION THIRrtEN -- TELECOMMUNICATION 55. Typesoftelecommunication links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 56.TelepfrOne . . . . . . . 34 57. Powerlinecarrier(PLC). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 58. Microwave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 59. Radioiink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 60. OpticalteIecommunication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 61. Classificationofdatatobetransmitted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 62. Fastresponsetelecommunication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 63. Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 SsKncm Fo[w~[-~ – AUXILIARY POWERSUPPLIFS 64. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 65. Reliabilityandloadclassification . . . . . . . . . . . . . . . . . . . . 36 66. A.C.auxiliarysupplies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 67. Batteriesanduninterruptiblesupplie s(UPS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 68. Emergencysupply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 SWTION FII_rii~N – AUDIBLE NOISE 69. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 70. Publicnuisance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 71. Noiseinworkingareas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 SECTION SIXTEEN – HARMONIC INTERFERENCE – A.C. 72. A.C.sideharmonicgeneration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 73. Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 74. lnterferencedisturbancecriteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 75. Levelsforinterference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 76. Fllterperformance . . . . . . . . . . . . . . . . . . . 43 SECTION SEVENTLLN – 77. D.C.sideinterference . , . . . . . . 43 78. D.C.filterperformance . . . . . 45 79. Specification requirements . 46 SKTION EIGHIt~\ -. POWER LINE CARRIER INIERFE.RENCE 80. Cieneral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 81. Performancespecification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 2