BRITISH STANDARD Guide to Acceptance tests for steam turbine speed control systems The European Standard EN 61064:1993 has the status of a British Standard UDC 621.165-531.6:621.3:620.1 BS EN 61064:1993 IEC 1064:1991 BS EN 61064:1993 Cooperating organizations The European Committee for Electrotechnical Standardization (CENELEC), under whose supervision this European Standard was prepared, comprises the national committees of the following countries: Austria Belgium Denmark Finland France Germany Greece Iceland Ireland This British Standard, having been prepared under the direction of the Machinery and Components Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 15 August 1993 © BSI 11-1999 The following BSI references relate to the work on this standard: Committee reference MCE/13 Draft for comment 87/75409 DC ISBN 580 22445 Italy Luxembourg Netherlands Norway Portugal Spain Sweden Switzerland United Kingdom Amendments issued since publication Amd No Date Comments BS EN 61064:1993 Contents Cooperating organizations National foreword Foreword Text of EN 61064 National annex NA (informative) Committees responsible National annex NB (informative) Cross-references © BSI 11-1999 Page Inside front cover ii Inside back cover Inside back cover i BS EN 61064:1993 National foreword This British Standard has been prepared under the direction of the Machinery and Components Standards Policy Committee and is the English language version of EN 61064:1993 Acceptance tests for steam turbine speed control systems published by the European Committee for Electrotechnical Standardization (CENELEC) It is identical with IEC 1064:1991 published by the International Electrotechnical Commission (IEC) For graphical symbols, and letter symbols and signs approved by the IEC for general use, readers are referred to: — IEC Publication 27: Letter symbols to be used in electrical technology; — IEC Publication 617: Graphical symbols for diagrams The symbols and signs contained in the present publication have either been taken from IEC Publications 27 or 617, or have been specifically approved for the purpose of this publication For general terminology, readers are referred to IEC Publication 50: International Electrotechnical Vocabulary (IEV), which is issued in the form of separate chapters each dealing with a specific field, the General Index being published as a separate booklet Full details of the IEV will be supplied on request The terms and definitions contained in the present publication have either been taken from the IEV or have been specifically approved for the purpose of this publication EN 61064 was produced as a result of international discussion in which the United Kingdom took an active part A British Standard does not purport to include all the necessary provisions of a contract Users of British Standards are responsible for their correct application Compliance with a British Standard does not of itself confer immunity from legal obligations Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages to 30, an inside back cover and a back cover This standard has been updated (see copyright date) and may have had amendments incorporated This will be indicated in the amendment table on the inside front cover ii © BSI 11-1999 EN 61064 EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM February 1993 UDC 621.165-531.6:621.3:620.1 Descriptors: Steam turbine, control system, speed, overspeed protection, acceptance test English version Acceptance tests for steam turbine speed control systems (IEC 1064:1991) Essais de réception des sytèmes de régulation de vitesse des turbines vapeur (CEI 1064:1991) Abnahmeprüfungen für Dampfturbinen-Regelsysteme (IEC 1064:1991) This European Standard was approved by CENELEC on 1992-12-09 CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels © 1993 Copyright reserved to CENELEC members Ref No EN 61064:1993 E EN 61064:1993 Foreword The CENELEC questionnaire procedure, performed for finding out whether or not the International Standard IEC 1064:1991 could be accepted without textual changes, has shown that no common modifications were necessary for the acceptance as European Standard The reference document was submitted to the CENELEC members for formal vote and was approved by CENELEC as EN 61064 on December 1992 The following dates were fixed: — latest date of publication of an identical national standard (dop) 1993-12-01 — latest date of withdrawal of conflicting national standards (dow) 1993-12-01 For products which have complied with the relevant national standard before 1993-12-01, as shown by the manufacturer or by a certification body, this previous standard may continue to apply for production until 1998-12-01 Annexes designated “normative” are part of the body of the standard In this standard, Annex A and Annex ZA are normative © BSI 11-1999 EN 61064:1993 Contents Page Foreword Scope and object Normative reference Terms, symbols, definitions and units Guiding principles 4.1 Matters on which agreement shall be reached 4.2 Time of carrying out tests 4.3 Preparation for acceptance tests 4.4 Instruments 4.5 Test report Speed governing system tests 5.1 Turbine at standstill 5.2 Turbine at no-load 5.2.1 Overview 5.2.2 Test procedure for determination of static characteristics 10 5.2.3 Determination of dead band 10 5.2.4 Speed range determination 10 5.2.5 Stability 10 5.3 Turbine on load 11 5.3.1 Overview 11 5.3.2 Test conditions 11 5.3.3 Load-steam flow demand relationship 11 5.3.4 Dead band determination — Overview 11 5.3.5 Dead band determination — Method 12 5.3.6 Dead band determination — Method 12 5.3.7 Determination of steady-state speed regulation — Method 12 5.3.8 Determination of steady-state speed regulation — Method 13 5.3.9 Determination of incremental speed regulation — Method 13 5.3.10 Determination of incremental speed regulation — Method 13 5.3.11 Stability 13 5.4 Dynamic tests of the speed governing system by sudden load rejection to no-load 13 5.4.1 Overview 13 5.4.2 Operating conditions 13 5.4.3 Test procedure 14 5.4.4 Test results 15 5.4.5 Stability 15 Overspeed protection system tests 15 © BSI 11-1999 6.1 Turbine at standstill 6.2 Turbine at no-load 6.3 Turbine on load 6.4 Dynamic testing of overspeed protection system by turbine trip from maximum load 6.4.1 Overview 6.4.2 Operating conditions 6.4.3 Test procedure 6.4.4 Test results Annex A (normative) General guidance Annex ZA (normative) Other international publications quoted in this standard with the references of the relevant European publications Figure — Diagram of condensing reheat steam turbine set Figure — Static characteristics at no-load Figure — Speed-speed changer setting relationship Figure — Static characteristics on load Figure — Cylinder fluid pressure versus servomotor stroke Figure — Servomotor stiffness characteristic Figure — Network frequency-load relationship Figure — Static characteristic of the speed governing system for one setting of the speed changer Figure — Block-diagram of a typical speed governing system Table Table Table Page 15 15 15 15 15 15 15 15 17 29 19 21 22 23 24 25 26 27 28 14 blank EN 61064:1993 Scope and object This International Standard applies primarily to constant-speed steam turbines driving a.c generators at power stations, for testing speed control systems consisting of speed governing and overspeed protection systems It may also be used, where appropriate, for other types of steam turbines The purpose of acceptance tests of steam-turbine speed governing and overspeed protection systems is to verify any criteria quoted in the manufacturer’s guarantees Such tests will generally be carried out to check compliance with IEC 45-1 The criteria may include: a) steady-state speed regulation (speed governing droop); b) steady-state incremental speed regulation (incremental speed governing droop); c) range of speed at no-load corresponding to the extreme settings of the speed changer; d) dead band of the speed governing system; e) stability of the speed governing system; f) maximum transient increase of speed following full load rejection and any partial load rejections, with the speed governing system in operation; g) overspeed trip setting; h) maximum transient overspeed following full load rejection on the failure of the speed governing system No 10 11 12 13 © BSI 11-1999 Power or load Pressure Temperature Angular speed Rotational speed Term Selection of the tests to be carried out and procedures for other tests not covered by this specification shall be agreed upon between the manufacturer and the purchaser Normative reference The following standard contains provisions which, through reference in this text, constitute provisions of this International Standard At the time of publication, the edition indicated was valid All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below Members of IEC and ISO maintain registers of currently valid International Standards IEC 45:1991, Steam turbines — Part 1: Specifications Terms, symbols, definitions and units Using these rules it is recommended to employ the symbols, definitions and units that are given in Table and Table and in Figure Table lists basic terms, symbols, and units, while Table presents terms, symbols, definitions, and units of parameters specific to this standard IEC 45-1 definitions are also applicable Table Voltage Current Position or stroke of servomotors Position or stroke of valves Position or stroke of pilots Time constant, characteristic time of element Time as independent variable Speed or load setting point Symbol L p e n U I s h x T t y Unit MW or kW MPa or bar K or °C rad/s Hz, rev/s (rev/min) V A mm, rad or (°) mm, rad or (°) mm, rad or (°) s s % or other EN 61064:1993 No Symbol Rated speed Minimum controlled speed n1 at no-load Maximum controlled speed n2 at no-load Temporary speed rise Maximum speed rise Maximum transient speed nm Maximum transient overspeed nops Overspeed trip setting ns Maximum continuous rating (MCR) (electrical generating set) Lo Maximum capability Lmax 10 Term no Table Definition The speed at which the turbine is specified to operate at its rated output Unit Hz rev/s rev/min The speed at no-load corresponding to the lower Hz setting of the speed changer rev/s rev/min The speed at no-load corresponding to the upper Hz setting of the speed changer rev/s rev/min The transient increase in turbine speed following Hz a load rejection, with the speed governing system rev/s in operation The rated temporary speed rise rev/min applies if the rated output is rejected at rated speed The maximum transient increase in turbine Hz speed following a load rejection, with the speed rev/s governing system inoperative The rated rev/min maximum speed rise applies if the rated output is rejected at rated speed The maximum transient increase in turbine Hz speed following rejection of maximum capability rev/s by disconnecting the generator from the electrical rev/min system (with auxiliary supplies previously disconnected) and the speed governing system in operation The maximum rotational speed following Hz rejection of maximum capability by disconnecting rev/s the generator from the electrical system (with rev/min auxiliary supplies previously disconnected) and the speed governing system inoperative The speed at which the overspeed trip is set to Hz operate rev/s rev/min The power output assigned to the MW turbine-generator by the supplier, at which the or unit may be operated for an unlimited time, not kW exceeding the specified life, at the specified terminal conditions This is the rating which will normally carry a guarantee of heat rate The governing valves will not necessarily be fully open (Also referred to as rated output, rated power or rated load) The maximum power output that the turbine can MW produce with the governing valves fully open and or at the specified initial steam conditions kW (Also referred to as valves-wide-open capability or maximum load) © BSI 11-1999 EN 61064:1993 A.2.2 For turbines with no main-steam isolating valve before the stop valve (and, naturally, no bypass), or by agreement between manufacturer and user, the speed can be decreased by partial closing of the turbine stop valve A.2.3 On those turbines with HP cylinder bypass system, the changing of the IP turbine steam flow is carried out by adjusting the HP turbine bypass valve, with the HP stop valvesclosed A.2.4 The following method is applicable for turbines provided with two or more sets of high pressure stop and control valves In this case, all high pressure stop valves are closed, except one to feed the turbine with live steam If the operational high pressure stop valve feeds the turbine through several control valves with individual servomotors, then only one of these control valves is left in operation Others are closed by their individual control or test circuits The steam flow is then changed by adjusting (with the help of the control or test circuit) the servomotor of the high pressure control valve feeding the turbine The value of rotational speed deviation, corresponding to the change in steam flow, shall cover the whole movement range (between extreme positions) of the control valve servomotors associated with the closed high pressure stop valves The stop valve of the other high pressure stop and control valves set is then opened and the stop valve of the operational valves set is closed The test with the rotational speed changing is repeated by analogy with the method described above A.2.5 To obtain the relation between valve position and speed for the whole deviation of the servomotor it is possible to close all stop valves with the speed governing system in operation and the turbine running at a speed near rated speed The natural speed decrease causes the control valves to open up to maximum opening This speed-valve position’s characteristic is obtained only in the direction of decreasing speed A.3 Schematic guide for clause numbers of acceptance tests of steam turbine control systems Parameter or characteristic Preliminary — correct operation Common — static relationships Turbine operation mode At standstill At no-load On load 5.1 5.2.2 , A.2 5.2.4 Speed range Dead band Speed governor Speed governing system without steam forces 5.1 , A.1 Speed governing system on load 5.2.3 Method Method 5.3.4 , 5.3.5 5.3.4 , 5.3.5 5.3.4 , 5.3.6 5.3.7 5.3.9 5.3.8 5.3.10 Speed regulation Steady state speed regulation Steady state incremental speed regulation Dynamic properties Stability Maximum transient speed 5.2.5 5.3.11 , 5.4.5 5.4.3 , 5.4.4 6.2 6.3 6.4 Overspeed protection Overspeed trip setting Maximum transient overspeed 18 6.1 © BSI 11-1999 Figure — Diagram of condensing reheat steam turbine set EN 61064:1993 © BSI 11-1999 19 EN 61064:1993 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 20 = = = = = = = = = = = = = = = = = = = = = = = = = = = = main-steam isolating valve main-steam isolating valve bypass valve stop-valve servomotor control-valve servomotor high pressure cylinder bypass valve turbine stop valve turbine control valve high pressure cylinder reheat control (intercept) valve reheat stop valve reheat stop valve servomotor reheat control (intercept) valve servomotor low pressure cylinder A.C generator condenser steam-extraction control valve servomotor steam-extraction control valve steam-extraction stop valve servomotor steam-extraction stop valve bled (extraction) steam isolating valve servomotor bled (extraction) steam isolating valve (non-return valve) intermediate pressure cylinder regenerative feed-water heater overspeed trip speed governor remote turbine trip device speed load changer steam flow demand Figure — Nomenclature © BSI 11-1999 EN 61064:1993 Figure 2a — Steam flow demand-speed relationship Figure 2b — Servomotor final link position-speed relationship Figure — Static characteristics at no-load © BSI 11-1999 21 EN 61064:1993 Figure — Speed-speed changer setting relationship 22 © BSI 11-1999 EN 61064:1993 Figure 4a — Load-steam flow demand relationship Figure 4b — Load-servomotor final link position relationship Figure — Static characteristics on load © BSI 11-1999 23 EN 61064:1993 Figure — Cylinder fluid pressure versus servomotor stroke 24 © BSI 11-1999 Figure — Servomotor stiffness characteristic EN 61064:1993 © BSI 11-1999 25 EN 61064:1993 Figure — Network frequency-load relationship 26 © BSI 11-1999 EN 61064:1993 Figure — Static characteristic of the speed governing system for one setting of the speed changer © BSI 11-1999 27 Figure — Block-diagram of a typical speed governing system EN 61064:1993 28 © BSI 11-1999 EN 61064:1993 Annex ZA (normative) Other international publications quoted in this standard with the references of the relevant European publications When the international publication has been modified by CENELEC common modifications, indicated by (mod), the relevant EN/HD applies IEC publication Date Title EN/HD Date 45-1 1991 Steam turbines — Part 1: Specifications EN 60045-1 1993 © BSI 11-1999 29 30 blank BS EN 61064:1993 National annex NA (informative) Committees responsible The United Kingdom participation in the preparation of this European Standard was entrusted by the Machinery and Components Standards Policy Committee (MCE/-) to Technical Committee MCE/13 upon which the following bodies were represented: Association of Consulting Engineers Electricity Association Electricity Supply Industry in England and Wales North of Scotland Hydro-electric Board Power Generation Association (BEAMA Ltd.) South of Scotland Electricity Board Coopted members National annex NB (informative) Cross-references Publication referred to Corresponding British Standard IEC 45-1:1991 © BSI 11-1999 BS EN 60045-1:1993 Guide to steam turbine procurement BS EN 61064:1993 IEC 1064:1991 BSI — British Standards Institution BSI is the independent national body responsible for preparing British Standards It presents the UK view on standards in Europe and at the international level It is incorporated by Royal Charter Revisions British Standards are updated by amendment or revision Users of British Standards should make sure that they possess the latest amendments or editions It is the constant aim of BSI to improve the quality of our products and services We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover Tel: 020 8996 9000 Fax: 020 8996 7400 BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services Tel: 020 8996 9001 Fax: 020 8996 7001 In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as British Standards, unless otherwise requested Information on standards BSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service Various BSI electronic information services are also available which give details on all its products and services Contact the Information Centre Tel: 020 8996 7111 Fax: 020 8996 7048 Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards For details of these and other benefits contact Membership Administration Tel: 020 8996 7002 Fax: 020 8996 7001 Copyright Copyright subsists in all BSI publications BSI also holds the copyright, in the UK, of the publications of the international standardization bodies Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means – electronic, photocopying, recording or otherwise – without prior written permission from BSI This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained BSI 389 Chiswick High Road London W4 4AL If permission is granted, the terms may include royalty payments or a licensing agreement Details and advice can be obtained from the Copyright Manager Tel: 020 8996 7070