1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationControllers with analogue sig als for use in industrial-process control systemsPart 1: Methods of evaluating the performanceBS EN 60546-1:2010nNational forewordThis British Stand
2、ard is the UK implementation of EN 60546-1:2010. It isidentical to IEC 60546-1:2010. It supersedes BS EN 60546-1:1993, which willbe withdrawn on 1 October 2013.The UK participation in its preparation was entrusted by Technical CommitteeGEL/65, Measurement and control, to Subcommittee GEL/65/2, Eleme
3、nts ofsystems.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions of acontract. Users are responsible for its correct application. BSI 2011 ISBN 978 0 580 62203 8 ICS 25.040.40Compl
4、iance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 February 2011.Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS EN 60546-1:2010EUROP
5、EAN STANDARD EN 60546-1 NORME EUROPENNE EUROPISCHE NORM October 2010 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels 2010 CENELEC -
6、All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60546-1:2010 E ICS 25.040.40 Supersedes EN 60546-1:1993English version Controllers with analogue signals for use in industrial-process control systems - Part 1: Methods of evaluating the perfo
7、rmance (IEC 60546-1:2010) Rgulateurs signaux analogiques utiliss pour les systmes de conduite des processus industriels - Partie 1: Mthodes dvaluation des performances (CEI 60546-1:2010) Regler mit analogen Signalen fr die Anwendung in Systemen der industriellen Prozesstechnik - Teil 1: Methoden zur
8、 Beurteilung des Betriebsverhaltens (IEC 60546-1:2010) This European Standard was approved by CENELEC on 2010-10-01. 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 withou
9、t 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
10、 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, Bulgaria, Croatia, Cyprus, the Czech Republi
11、c, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 60546-1:2010EN 60546-1:2010 - 2 - Foreword T
12、he text of document 65B/659A/CDV, future edition 3 of IEC 60546-1, prepared by SC 65B, Devices AKKpp= (6b) ATT1I1+= (6c); DDTAT = (6d) where t is the time; y is the output signal (correcting variable); y0is the output signal at time t = 0 (controller output balance); x is the measured value (control
13、led variable); w is the set point value (reference input variable); Kpis the proportional action factor (proportional action coefficient (see Note 1); K1is the integral action factor (integral action coefficient (see Note 1); KDis the derivative action factor (derivative action coefficient (see Note
14、 1); TIis the reset time; TDis the rate time; x and w, and consequently also y can be functions of time t, and: e is the error or controller off-set, i.e.: x w; is the angular velocity. NOTE 1 For the definition of this term, see IEC 60050-351. NOTE 2 This standard is limited to P, PI, PD or PID con
15、trollers. NOTE 3 The factors Kp, K1and KDmay have the sign “plus” or “minus”; it is usual to associate “direct action” with the positive sign and “reverse action” with the negative sign. NOTE 4 Symbols with prime (Kp, TITD) represent nominal values, in contrast to effective values. NOTE 5 Integral-a
16、ction time constant and derivative-action time constant refer only to pure integral or derivative-action controllers (IEC 60050-351). BS EN 60546-1:2010 12 60546-1 IEC:2010 There are controllers with still other structures, for example where the differentiation is applied only to the measured value
17、x, not to (x w). Equation (5) therefore becomes: () () ()+=xtATtwxTAwxAKyyt0DIp0ddd1(7) 4.2 Limitations The equations describing the performance of an actual controller are usually different from equations (2) to (7) because they include time constants and limitations. Two commonly encountered devia
18、tions from the idealized controller equations can be expressed as follows: a) Maximum integral gain VIBecause of the finite integral gain of actual controllers, the integral part of equations (2) and (3) is an approximation of the actual response only for sufficiently high frequencies. For low frequ
19、encies, a controller may have an integral action integral term of equation (4) expressed in the frequency domain as follows: ()1Ipj1jVTVKFI+= (8) b) Maximum derivative gain VDBecause of the limited derivative gain of actual controllers, the derivative terms of equations (2) and (3) are an approximat
20、ion of the actual response only for sufficiently low frequencies. In the most simple case, there may be additional time constant and proportional terms. The derivative term of equation (4) may then be expressed, in the frequency domain, as follows: Derivative action and time constant ()TTKFj1jjDp+=
21、(9) or proportional action, derivative action and time constant ()TTKFj1j1jDp+= (10) where T is the time constant of a first order time delay. The ratio TTDmay be constant for all adjustable values of TD(depending upon the design of the controller). The ratio TTDis then called maximum derivative gai
22、n or VD. 4.3 Dial graduation of controllers The action factors and action times as used in the equations shown above give an idealized description of the performance of a controller. Their values may differ from the values which are the graduations marked on the dials of the controller. The relation
23、ship between the dial graduations and the effective values, i.e. the “interaction formula”, shall be provided by the BS EN 60546-1:201060546-1 IEC:2010 13 manufacturer. The relationship may be expressed in algebraic form or by graphs, tables, diagrams, etc. 5 General test conditions 5.1 Environmenta
24、l conditions As per IEC 61298-1: 5.1.1 Recommended range of ambient conditions for test measurements Temperature range 15 C to 35 C Relative humidity 45 % to 75 % Atmospheric pressure 86 kPa to 106 kPa Electromagnetic field value to be stated, if relevant The maximum rate of ambient temperature chan
25、ge permissible during any test shall be 1 C in 10 min. These conditions may be equivalent to normal operating conditions. 5.1.2 Standard reference atmosphere Temperature 20 C Relative humidity 65 % Atmospheric pressure 101,3 kPa This standard reference atmosphere is the atmosphere to which values me
26、asured under any other atmospheric conditions are corrected by calculation. It is recognized, however, that in many cases a correction factor for humidity is not possible. In such cases, the standard reference atmosphere takes account of temperature and pressure only. This atmosphere is equivalent t
27、o the normal reference operating conditions usually identified by the manufacturer. 5.1.3 Standard atmosphere for referee measurements When correction factors to adjust atmospheric-condition-sensitive parameters to their standard reference atmosphere value are unknown, and measurements under the rec
28、ommended range of ambient atmospheric conditions are unsatisfactory, repeated measurements under closely controlled atmospheric conditions may be conducted. For the purpose of this standard, the following atmospheric conditions are given for referee measurements. Nominal value Tolerance Temperature
29、20 C 2 C Relative humidity 65 % 5 % Atmospheric pressure 86 kPa to 106 kPa For tropical, sub-tropical or other special requirements, alternate referee atmospheres may be used. BS EN 60546-1:2010 14 60546-1 IEC:2010 5.2 Supply conditions 5.2.1 Reference values The values shall be specified by the man
30、ufacturer or agreed upon between user and manufacturer. 5.2.2 Tolerances As per IEC 61298-1: 1) Electrical supply rated voltage 1 % rated frequency 1 % harmonic distortion (a.c. supply) less than 5 % ripple content (d.c. supply) less than 0,1 % 2) Pneumatic supply rated pressure 1 % supply air tempe
31、rature ambient temperature 2 C supply air humidity dew point at least 10 C below controller temperature oil and dust content oil less than 1 106by weight dust absence of particles greater than 3 m diameter 5.3 Load impedance As per IEC 61298-1: The value given by the manufacturer shall be used as th
32、e reference value. For electric controllers, if the manufacturer gives more than one value, the load impedance shall be taken as equal to: the minimum value specified by the manufacturer for controllers with direct voltage output signal; the maximum permissible value for controllers with direct curr
33、ent output signal. Unless otherwise stated by the manufacturer, for pneumatic controllers, an 8 m length of 4 mm internal diameter rigid pipe followed by 20 cm3capacity shall be used for load impedance. NOTE This arrangement is specified for steady-state tests on pneumatic controllers. For dynamic t
34、ests, a 100 cm3capacity may be used in place of the 20 cm3. 5.4 Other test conditions Other conditions to consider when performing general tests are as follows: on the input signals: spurious induced voltages or pressure fluctuations which may affect the measurement shall not be present; controller
35、position during operation: normal mounting position specified by the manufacturer. Throughout each test, however, the mounting position of the controller should not change by more than 3 about any axis; external mechanical constraints: they shall be negligible. BS EN 60546-1:201060546-1 IEC:2010 15
36、The limit of error of the measuring systems used for the tests shall be stated in the test report and should be smaller than or equal to one-fourth of the stated limit of error of the instrument tested. 5.5 Stabilizing the controller output For the purpose of the following tests, the controller may
37、be stabilized in the following manner (see Figure 2a2). a) Set the controller in a closed loop configuration by putting the switch in position B. Set the controller for reverse action, or the differential amplifier to a gain of 1. b) Set the proportional band to 100 % if possible and unless specifie
38、d otherwise. c) Set the derivative action for minimum effect (minimum rate time or off). d) Set the integral action for maximum effect (minimum reset time). e) Set the set point to 50 %. f) If necessary, adjust the bias of generator No. 3 in order to obtain the desired output. Set point generator No
39、. 1 Measured value generator No. 2 Bias generator No. 3 Offset measurement Controller under test Measured value/output recorder Set point Measured value Output Load Damping Switch A B 1A = open loop B = closed loop IEC 1621/10Generator No. 1 Generator for set point input For controller with external
40、 set point Generator No. 2 DC for steady state input Step for integral action test Ramp for derivative action test Generator No. 3 Sine wave for frequency response test and accelerated life test DC for fixed bias levels 2a) Arrangement for open loop or closed loop tests 2)Damping is sometimes necess
41、ary for stabilization. BS EN 60546-1:2010 16 60546-1 IEC:2010 Measured value/ output recorder FlowmeterThrottle valve Throttle valve FlowmeterAir supply Atmosphere w x Circuit as in Figure 2a Controller under test Damping IEC 1918/102b) Arrangement for measuring air flow Figure 2 Test arrangements 6
42、 Offset 6.1 Test set-up The offset test only applies to controllers with integral action. The circuit arrangement shown in Figure 2a or an equivalent arrangement shall be used. The set point and the measured value shall be connected to the input of a differential measuring device. The selector switc
43、h shall be set in position B, thus obtaining a stable “closed loop” condition. Changing the bias of generator No. 3 allows the controller output y to be varied over the full span for any value of the controller set point value and measured value. 6.2 Initial conditions Initial conditions shall be as
44、 specified in Clause 5. 6.3 Test procedure 6.3.1 Offset at different values of XpThe offset will change for different values of proportional bands. The test procedures to determine the offsets are as follows: If the controller being tested has scale markings not directly in terms of proportional ban
45、d, or reset and rate times, the relationship of such markings to the parameters used in this standard needs to be established. The method specified in this clause shall be used with the instrument set to the scale markings which correspond to the values specified. With the controller stabilized in a
46、ccordance with 5.5, adjust the bias of generator No. 3 until the output is 50 %. After allowing sufficient time for the controller output to stabilize, measure the offset. The measurement shall be repeated with the proportional band adjusted to the minimum value and then to the maximum value (or to
47、the nearest scale markings). BS EN 60546-1:201060546-1 IEC:2010 17 Set the proportional band to 100 %. Repeat measurements as described above for all nine combinations of the three values of the set point: 10 %, 50 % and 90 % of span and the three values of output: 10 %, 50 % and 90 % of span. Switc
48、h the controller to direct action. At the same time adjust the gain of the differential amplifier to 1. Measure offset with Xp= 100 %, set point = 50 % and output = 50 %. Further measurements may be made with other values of the proportional band or of the set point at special points, in order to in
49、terpolate between some preceding readings where there are significant variations in the offset. Offset shall be reported expressed in per cent of span of measured value. 6.3.2 Effect of changes of reset and rate time Adjust set point to 50 %, output to 50 % and proportional band Xpto 100 %. With the reset time set to its minimum value, change the rate time from i
