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1、BRITISH STANDARD BS EN 60891:1995 IEC 891:1987 (including Amendment No. 1:1992) Procedures for temperature and irradiance corrections to measured I-V characteristics of crystalline silicon photovoltaic devices The European Standard EN 60891:1994 has the status of a British Standard UDC 621.383:621.3
2、17.08 Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 02:22:04 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 60891:1995 This British Standard, having been prepared under the direction of the Electrotechnical Sector Board (L/l), was published under the authority of the Standards Board and c
3、omes into effect on 15 April 1995 BSI 01-2000 The following BSI references relate to the work on this standard: Committee reference EPL/47 Draft announced in BSI News October 1993 ISBN 0 580 24010 X Committees responsible for this British Standard The preparation of this British Standard was entrust
4、ed to Technical Committee EPL/47, Semiconductors, upon which the following bodies were represented: Federation of the Electronics Industry Ministry of Defence National Supervising Inspectorate The following bodies were also represented in the drafting of the standard through subcommittees: Associati
5、on of Manufacturers Allied to the Electrical and Electronics Industry (BEAMA Ltd.) Society of British Aerospace Companies Limited Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 02:22:04 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN
6、60891:1995 BSI 01-2000i Contents Page Committees responsibleInside front cover National forewordii Foreword2 Text of EN 608913 List of referencesInside back cover Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 02:22:04 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 60891:1995 ii BSI 01-200
7、0 National foreword This British Standard has been prepared by Technical Committee EPL/47 and is the English language version of EN 60891:1994, Procedures for temperature and irradiance corrections to measured I-V characteristics of crystalline silicon photovoltaic devices, published by the European
8、 Committee for Electrotechnical Standardization (CENELEC). It is identical with IEC 891:1987, together with its amendment No. 1:1992, published by the International Electrotechnical Commission (IEC). A British Standard does not purport to include all the necessary provisions of a contract. Users of
9、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 2 to 6, an inside bac
10、k 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. Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 02:22:04 GMT+00:00 2006, Uncontrolled Copy, (c) BSI
11、EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 60891 September 1994 UDC 621.383:621.317.08 Descriptors: Photovoltaic devices, crystalline silicon, irradiance corrections, I-V characteristics, temperature corrections English version Procedures for temperature and irradiance corrections to measu
12、red I-V characteristics of crystalline silicon photovoltaic devices (IEC 891:1987 + A1:1992) Procdures pour les corrections en fonction de la temprature et de lclairement appliquer aux caractristiques I-V mesures des dispositifs photovoltaques au silicium cristallin (CEI 891:1987 + A1:1992) Verfahre
13、n zur Korrektur von Temperatur und Einstrahlung von gemessenen Strom-Spannungs-Kennlinien von photovoltaischen Betriebsmitteln aus kristallinen Silizium (IEC 891:1987 + A1:1992) This European Standard was approved by CENELEC on 1994-03-08. CENELEC members are bound to comply with the CEN/CENELEC Int
14、ernal 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
15、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. CEN
16、ELEC 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
17、 Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1994 Copyright reserved to all CENELEC members Ref. No. EN 60891:1994 E Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 02:22:04 GMT+00:00
18、 2006, Uncontrolled Copy, (c) BSI EN 60891:1994 BSI 01-2000 2 Foreword The CENELEC questionnaire procedure, performed for finding out whether or not the International Standard IEC 891:1987 and its amendment 1:1992 could be accepted without textual changes, has shown that no common modifications were
19、 necessary for the acceptance as a European Standard. The reference document was submitted to the CENELEC members for formal vote and was approved by CENELEC as EN 60891 on 8 March 1994. The following dates were fixed: Annexes designated “normative” are part of the body of the standard. In this stan
20、dard, Annex ZA is normative. Contents Page Foreword2 1Scope3 2Correction procedures3 3Determination of temperature coefficients3 4Determination of internal series resistance4 5Determination of curve correction factor4 Annex ZA (normative) Other international publications quoted in this standard with
21、 the references of the relevant European publications6 Figure 1 Determination of Rs5 latest date of publication of an identical national standard(dop) 1995-03-15 latest date of withdrawal of conflicting national standards(dow) 1995-03-15 Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 02:22:0
22、4 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 60891:1994 BSI 01-20003 This standard gives procedures that should be followed for temperature and irradiance corrections to the measured I-V characteristics of crystalline silicon photovoltaic devices only. 1 Scope This standard describes the procedur
23、es for temperature and irradiance corrections to the measured I-V characteristics of crystalline silicon photovoltaic devices. It includes procedures for the determination of temperature coefficients, internal series resistance and curve correction factor. These procedures are applicable over an irr
24、adiance range of 30 % of the level at which the measurements were made. NOTE 1These procedures are limited to linear devices. NOTE 2The photovoltaic devices include a single solar cell, a sub-assembly of solar cells, or a flat module. A different set of values apply for each type of device. Although
25、 the determination of temperature coefficients for a module (or sub-assembly of cells) may be calculated from single cell measurements, it should be noted that the internal series resistance and curve correction factor should be separately measured for a module or sub-assembly of cells. NOTE 3The te
26、rm “test specimen” is used to denote any of these devices. 2 Correction procedures The measured current-voltage characteristic shall be corrected to Standard Test Conditions or other selected temperature and irradiance values by applying the following equations: NOTE 1The units of all parameters of
27、the preceding equations should be consistent. NOTE 2The general recommendations given in IEC Publication 27: Letter Symbols to be Used in Electrical Technology, are applicable, except where this publication gives different recommendations, in which case the latter should be followed. NOTE 3In IEC Pu
28、blication 27, V is recommended only as a reserve symbol. For the purpose of this standard the letter V is recommended as an alternate chief symbol for voltage and derived quantities because many countries use it in the field of photovoltaic devices and generally in the field of electronics. NOTE 4If
29、 the temperature, TR, of the reference device during a measurement differs by more than 2 C from the temperature at which it was calibrated, lSR should be temperature corrected as follows: lSR= lSROR(TR TO) NOTE 5 and are temperature coefficients of only the module. If the module is provided with a
30、diode in series, the voltage temperature corrections should be applied excluding this diode. If the diode is not accessible, its characteristics vs. temperature should be provided. 3 Determination of temperature coefficients The temperature coefficients of current () and voltage () vary with irradia
31、nce and to a lesser extent, with temperature. The coefficients are best measured in simulated sunlight as specified in IEC Publication XXX (under consideration), using a minimum of two representative solar cells of the same area and configuration as those in the relevant module. NOTE 1Any mismatch b
32、etween the cells in a module could adversely affect the accuracy of corrections made to the I-V characteristics of the module. NOTE 2The use of a pulsed simulator is preferred since it creates little additional heat that could affect the cell during the measurement. The procedure is as follows: 3.1
33、Attach a suitable temperature sensor to the test cell so that the temperature can be measured to an accuracy of 0.5 C. 3.2 Mount the test cell with good thermal contact to a temperature-controlled block and use the attached sensor to provide the control signal. 3.3 Mount the test cell as near as pos
34、sible to a suitable reference solar cell with their active surfaces in the test plane. The normal of the test cell and the reference solar cell shall be parallel within 5 C to the centre-line of the beam. 3.4 Set the irradiance at the test plane so that the reference solar cell (at 25 5 C) produces
35、its calibrated short-circuit current at the desired level. where: I1, V1are coordinates of points on the measured characteristics I2, V2are coordinates of the corresponding points on the corrected characteristic ISCis the measured short-circuit current of the test specimen IMRis the measured short-c
36、ircuit current of the reference device corrected, as necessary, to the temperature of the reference device during measurement of IMR. ISRis the short-circuit current of the reference device at the standard or other desired irradiance T1is the measured temperature of the test specimen T2is the standa
37、rd or other desired temperature and are the current and voltage temperature coefficients of the test specimen in the standard or other desired irradiance and within the temperature range of interest ( is negative) Rsis the internal series resistance of the test specimen Kis a curve correction factor
38、 where: lSROis the short circuit current of the reference device at the temperature at which it was calibrated. Ris the current temperature coefficient of the reference device. Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 02:22:04 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 60891:1994 4
39、BSI 01-2000 3.5 With the test cell stabilized at or near the minimum temperature of interest, measure its short-circuit current (ISC) and open-circuit voltage (VOC). NOTEAt sub-ambient temperature, precautions may be necessary to prevent condensation on the active surfaces of the test cell and refer
40、ence solar cell. This precaution could be accomplished by passing dry nitrogen gas over the active surfaces or by enclosing the cells in a vacuum chamber. 3.6 Stabilize the test cell at a temperature approximately 10 C above the previous level and repeat ISC and VOC measurements. Repeat this procedu
41、re at approximately 10 C increments up to the maximum temperature of interest. 3.7 Repeat the steps in Sub-clauses 3.1 to 3.6 on each of the other test cells. 3.8 Plot the values of ISC and VOC as a function of temperature and construct a least squares fit curve through each set of data. 3.9 From th
42、e slopes of the current and the voltage curves and at a point midway between the minimum and maximum temperature of interest, calculate c and c, the temperature coefficients for single cells. 3.10 For a module or other assembly of cells, calculate the temperature coefficients as follows: = np c = ns
43、 c where np is the number of cells in parallel and ns the number in series 4 Determination of internal series resistance RS may be determined in simulated sunlight by the following procedure: (see Figure 1, page 5). 4.1 Trace the current-voltage characteristic of the test specimen at room temperatur
44、e and at two different irradiances (magnitudes need not be known). During the two measurements the cell temperature shall not differ by more than 2 C. 4.2 Choose a point P on the higher characteristic, at a voltage slightly higher than Vp max. Measure I, the difference between the current at this po
45、int and . 4.3 Determine the point Q on the lower curve at which the current is equal to I. 4.4 Measure the voltage displacement V between points P and Q. 4.5 Calculate from: whereandare the two short-circuit currents 4.6 Repeat steps in Sub-clauses 4.3 to 4.5, using a characteristic taken at a third
46、 irradiance level and the same cell temperature, in combination with each of the first two curves to determine the and values. Rs is the mean of the three calculated values:, and . 5 Determination of curve correction factor K may be determined in simulated sunlight by the following procedure: 5.1 Tr
47、ace the current-voltage characteristic of the test specimen at an irradiance within 30 % of the selected level and at three different temperatures (T3, T4 and T5) over an interest range of at least 30 C. NOTEWhen measuring the characteristics of a module, precautions should be taken (for instance by
48、 enclosing the module in a temperature controlled chamber with a transparent window) to ensure uniformity of the cell temperature within 2 C of the intended level. 5.2 Using an assumed value of K (say 1.25 1037/C which is typical for a crystalline silicon cell) transpose the characteristic measured
49、at temperature T3 to temperature T4 by applying the following equations: I4= I3+ !(T4 T3) V4= V3 KI4(T4 T3) + (T4 T3) where: I3,V3are coordinates of points on the T3 temperature characteristic I4, V4are coordinates of the corresponding points on the T4 temperature characteristic 5.3 If the transposed T4 temperature characteristic does not coincide to the desired accuracy with that obtained by measurement, repeat step in Sub-clause 5.2 by inserting different values for K, until the transposed T4 temper