1、= 3404583 0075777 683 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 60868 April 1993 UDC 621.317.7 Supersedes HD 498 S2 : 1992 Descriptois: Measuring instnment, flickennetei; design, performance, specification, test English version Flickermeter - Functional and design specifications (IEC 868
2、: 1986 + Al : 1990) Mickenntre - Spcifications fonctionnelles et de conception Auslegungsspezif ikation (CE1 868 : 1986 + Al : 1990) Flickermeter - Funktionsbeschreibung und (IEC 868 : 1986 + Al : 1990) This European Standard was approved by CENELEC on 1993-03-09. CENELEC inembers are bound to compl
3、y with the CENICENELEC 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 Secr
4、etariat 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
5、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 Electr
6、otechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fiir Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels O 1093 Copyright reserved to CENELEC members Ref. No. EN 60868 : 1993 E 3qOq583 0075778 5LT Page 2 EN 60868: 1993 For
7、eword At the request of 72 Technical Board, HD 498 S2 : 1992 (IEC 868 : 1986 + Al : 1990) was submitted to the CENELEC voting procedure for conveision into a European Standard. The text of the International Standard was approved by CENELEC as EN 60868 on 9 March 1993, The following dates were fixed:
8、 - latest date of publication of an identical national standard (dp) 1994-03-01 - latest date of withdrawal of conflicting national standards (dow) - Aiinexes designated normative are pait of the body of the standard. In this standard, annex ZA is normative. m 3404583 0075779 4.56 Page 3 EN 60868 :
9、1993 CONTENTS Page INTRODUCTION . 4 Clause 1. Scope and object . 4 4 2. Description of the instrument . 3. Specification . 7 4. Type test specifications . 11 FIGURES 15 APPENDIX A - Evaluation of flicker severity on the basis of the output of the IEC ANNEX ZA - (normative) Other international public
10、ations quoted in this standard 17 21 flickermeter . with the references of the relevant European publications . m 3404583 0075780 178 m Page 4 EN 60868 : 1993 FLICKERMETER FUNCTIONAL AND DESIGN SPECIFICATIONS INTRODUCTION This report gives a functional and design specification for flicker measuring
11、apparatus intended to indicate the correct flicker perception level for all practical voltage fluctuation waveforms. Sufficient information is presented to enable such an instrument to be constructed. The method of flicker severity assessment from flickermeter output data will form the subject of ot
12、her publications. In its present form, this report is not intended to be an appendix to IEC Publications 555-3 : Disturbances in Supply Systems Caused by Household Appliances and Similar Electrical Equipment, Part 3 : Voltage Fluctuations. This report is based on specifications prepared by the Distu
13、rbances Study Committee of the Inter- national Union for Electroheat (UIE). 1. Scope aiid object The purpose of this report is to provide basic information for the design and the implementation It does not specify the method of calculating a flicker severity value, or give tolerable limit of an anal
14、ogue or digital flicker measuring apparatus. values. 2. Description of the instrument The description given below is based on an analogue implementation. A partly or completely digital meter is equally acceptable provided that it offers the same functional characteristics. The flickermeter architect
15、ure is described by the block diagram of Figure 1, page 29, and can be divided into two parts, each performing one of the following tasks : - simulation of the response of the lamp-eye-brain chain ; - on-line statistical analysis of the flicker signal and presentation of the results. The first task
16、is performed by blocks 2, 3 and 4 of Figure 1, whilst the second task is accom- plished by block 5. Although this last block is not mandatory, as flicker signal analysis can be performed off-line using a suitable recording medium, its inclusion is recommended because it will allow a more complete an
17、d efficient use of the instrument. 2.1 Block 1 - Input voltage adaptor and calibration checking circuit This block contains a signal generator to check the calibration of the flickermeter on site and a voltage adapting circuit that scales the mean r.m.s. value of the input mains frequency voltage do
18、wn to an internal reference level. In this way flicker measurements can be made independently from the actual input carrier voltage level and expressed as a percent ratio. Taps on the input 3404583 0075783 004 Page 5 EN 60868 : 1993 transformer establish suitable input voltage ranges to keep the inp
19、ut sigrial to the voltage adaptor within its permissible range. 2.2 Block 2 - Square law demodulator The purpose of this block is to recover the voltage fluctuation by squaring the input voltage scaled to the reference level, thus simulating the behaviour of the lamp. 2.3 Blocks 3 and 4 - Weighting
20、filters, squaring and smoothing or follow the selective filter circuit. demodulator output. Block 3 is composed of a cascade of two filters and a measuring range selector, which can precede The first filter eliminates the d.c. and double mains frequency ripple components of the The second does the s
21、haping of the flickermeter frequency response to the modulating fluctu- ation, as follows : the weighting filter block simulates the frequency response to sinusoidal voltage fluctuations of a coiled coil filament gas filled lamp (60 W - 230 V) combined with the human visual system. The response func
22、tion is based on the perceptibility threshold found for each frequency on 50% of the persons tested*. Block 4 is composed of a squaring multiplier and a first order low-pass filter. The human flicker sensation via lamp, eye and brain is simulated by the combined non-linear response of blocks 2,3 and
23、 4. Block 3 alone is based on the borderline perceptibility curve for sinusoidal voltage fluctuations ; the correct weighting of non-sinusoidal and stochastic fluctuations is achieved by an appropriate choice of the complex transfer function for blocks 3 and 4. Accordingly the correct performance of
24、 the model has also been checked with periodic rectangular signals as well as with transient signals. The output of block 4 represents the instantaneous flicker sensation. 2.4 Block 5 - On-line statistical analysis allowing direct calculation of significant evaluation parameters. methods of deriving
25、 measures of flicker severity by statistical analysis. Block 5 incorporates a microprocessor that performs an on-line analysis of the flicker level, thus A suitable interface allows data presentation and recording. The use of this block is related to The statistical analysis, whether performed on-li
26、ne by block 5 or off-line on a recording of the output of block 4, shall be made by subdividing the amplitude of the ficker level signal into a suitable number of classes. The flicker level signal is sampled at a constant rate. Every time that the appropriate value occurs, the counter of the corresp
27、onding class is in- cremented by one. In this way, the frequency distribution function of the input values is obtained. By choosing a scanning frequency sufficiently higher than the maximum flicker frequency, the final result at the end of the measuring interval represents the distribution of flicke
28、r level duration * A reference filament lamp for 100-130 V systems would have a different frequency response and would require a corresponding adjustment of the weighting filter. The characteristics of discharge lamps are totally diferent, and wider modifications of this report would be necessary to
29、 take them into account. 3404583 0075782 T40 Page 6 EN 60868 : 1993 2.5 in each class. Adding the content of the counters of all classes and expressing the count of each class relative to the total gives the probability density function of the flicker levels. From this, one obtains the cumulative pr
30、obability function used in the time-at-level statistical Figure 2, page 3 1, schematically represents the statistical analysis method, limited for simplicity of presentation to 1 O classes. From the cumulative probability function, significant statistical values can be obtained such as mean, standar
31、d deviation, flicker level being exceeded for a given percentage of time or, alter- natively, the percentage of time an assigned flicker level has been exceeded. method. The observation period is defined by two adjustable time intervals : Tshon and Tlong. The long interval defines the total observat
32、ion time and is always a multiple of the short interval : (T,ong= n a Tshort). For on-line processing, immediately after conclusion of each short time interval, the statistical analysis of the next interval is started and the results for the expired interval are made available for output. In this wa
33、y, n short time analyses will be available for a given observation period Tong, together with the results for the total interval. Cumulative probability function plots should preferably be made by using a Gaussian normal distribution scale. outputs The flickermeter diagram in Figure 1, page 29, show
34、s a number of outputs between blocks 1 and 5. The outputs marked with an asterisk are not essential, but may allow a full exploitation of the instrument potential for the investigation of voltage fluctuations. Further optional outputs may be considered. 2.5.1 The aim of optional output 1 and associa
35、ted r.m.s. meter is to display the voltage fluctuation waveform in terms of changes in r.m.s. value of the input voltage. This can be achieved by squaring, integrating between zero crossings on each half-cycle and square rooting the signal. In order to observe small voltage changes with good resolut
36、ion, an adjustable d.c. offset and rectification should be provided. 2.5.2 Output 2 is mainly intended for checking the response of block 3 and making adjustments. AV Output 3 gives an instantaneous linear indication of the relative voltage change - V expressed as per cent equivalent of an 8.8 Hz si
37、nusoidal wave modulation. This output is useful to select the proper measuring range. 2.5.3 2.5.4 Output 4 gives the 1 min integral of the instantaneous flicker sensation. 2.5.5 Output 5 represents the instantaneous flicker sensation and can be recorded on a strip-chart recorder for a quick on-site
38、evaluation, or on magnetic tape for long duration measurements and for later processing. m 3404583 0075783 987 m Page 7 EN 60868 : 1993 2.5.6 Output 6 in block 5 is connected to a serial digital interface suitable for a printer and a magnetic tape recorder. Using another digital to analogue converti
39、ng interface, analogue plots of the cumulative probability function can be obtained directly from this block. 3. Specification 3.1 Analogue response The overall analogue response from the instrument input to the output of block 4 is given in Tables I and II for sinusoidal and rectangular voltage flu
40、ctuations as defined in IEC Publi- cation 555-3. One unit output from block 4 corresponds to the reference human flicker percep- tibility threshold. Th response is centred at 8.8 Hz for sinusoidal modulation. The prescribed accuracy is achieved if the input values for sine and square-wave modulation
41、s are within * 5% of the tabulated values, for an output of one unit of perceptibility. TABLE I Normalized jlckermeter response for sinusoidal voltage fluctuations AV Input relative voltage fluctuation - for one unit of perceptibility at output V Hz 0.5 1 .o 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6
42、.5 7.0 7.5 8.0 8.8 Voltage fluctuation (%I 2.340 1.432 1.080 0.882 0.754 0.654 0.568 0.500 0.446 0.398 0.360 0.328 0.300 0.280 0.266 0.256 0.250 9.5 10.0 10.5 11.0 11.5 12.0 13.0 14.0 15.0 16.0 17.0 18.0 19.0 20.0 21.0 22.0 23.0 24.0 25.0 Voltage fluctuation (%I 0.254 0.260 0.270 0.282 0.296 0.312 0
43、.348 0.388 0.432 0.480 0.530 0.584 0.640 0.700 0.760 0.824 0.890 0.962 1.042 Page 8 EN 60868 : 1993 m 3404583 0075784 813 m TABLE II Normalized flickermeter response for rectangular voltage fluctuations AV Input relative voltage fluctuation - for one unit of perceptibility at output V Hz d 0.5 1 .o
44、1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.8 Voltage fluctuation (YO) 0.514 0.47 1 0.432 O. 40 1 0.374 0.355 0.345 0.333 0.316 0.293 0.269 0.249 0.231 0.217 0.207 0.201 O. 199 Hz 9.5 10.0 10.5 11.0 11.5 12.0 13.0 14.0 15.0 16.0 17.0 18.0 19.0 20.0 Voltage fluctuation (oh) 0.200 0.205
45、0.2 13 0.223 0.234 0.246 0.275 0.308 0.344 0.380 0.42 1 0.461 0.506 0.552 0.603 0.657 0.713 0.767 3.2 Input transformer The input voltage transformer must accept a wide range of nominal mains voltages and adapt them to the maximum level compatible with the operation of the following circuits. The mo
46、st common rated voltages, assuming a -30% to +20% deviation are listed in Table III. TABLE III Rated input voltage (vr.m.s.) 1 O0 115 127 160 220 230 240 380 420 I -30% (Vr.m.s.) 40 70 80.5 89 112 154 161 168 266 294 +20% (Vr.m.s.) 68 120 138 152 192 264 276 288 456 504 The prescribed total range sh
47、all therefore be 40 V r.m.s. to 504 V r.m.s. It is advisable to keep the variations of secondary voltage within a maximum excursion of 1 to 3.5 times and therefore the transformer should have at least two taps with transforming = 3904583 0075785 75T Page 9 EN 6868 : 1993 504 276 138 ratios - for pri
48、mary to secondary and - and - for the taps, where VR is the reference carrier level. VR VR VR The pass bandwidth of the transformer shall not introduce a significant attenuation ofthe Insulation level shall be 2 kV r.m.s. for 1 min and 2 kV peak for an 1.2/50 ps impulse. An modulation sidebands at k
49、 25 Hz. electrostatic shielding shall be provided between windings and suitably connected. 3.3 Voltage adaptor This circuit must keep the r.m.s. level of the modulated 50 Hz voltage at the input of block 2, at a constant reference value V, according to the specification of the input transformer, without modifying the modulating relative fluctuation. It shall have a response time (10% to 90% of the final value) to a step variation of the r.m.s. input value equal t9 1 min. The operating range of this circuit shall be sufficient to ensure a correct reproduction of input voltage flu
