1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationPhotovoltaic devices Procedures for temperature and irradiance corrections tomeasured I-V characteristicsBS EN 60891:2010National forewordThis British Standard is the UK implemen
2、tation of EN 60891:2010. It is identical to IEC 60891:2009. It supersedes BS EN 60891:1995 which is withdrawn.The UK participation in its preparation was entrusted to Technical CommitteeGEL/82, Photovoltaic Energy Systems.A list of organizations represented on this committee can be obtained onreques
3、t to its secretary.This publication does not purport to include all the necessary provisions of acontract. Users are responsible for its correct application. BSI 2010ISBN 978 0 580 65689 7ICS 27.160; 31.260Compliance with a British Standard cannot confer immunity fromlegal obligations.This British S
4、tandard was published under the authority of the StandardsPolicy and Strategy Committee on 3 Ju 2010.Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS EN 60891:2010ly1EUROPEAN STANDARD EN 60891 NORME EUROPENNE EUROPISCHE NORM March 2010 CENELEC European Committee for E
5、lectrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: Avenue Marnix 17, B - 1000 Brussels 2010 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref
6、. No. EN 60891:2010 E ICS 27.160 Supersedes EN 60891:1994English version Photovoltaic devices - Procedures for temperature and irradiance corrections to measured I-V characteristics (IEC 60891:2009) Dispositifs photovoltaques - Procdures pour les corrections en fonction de la temprature et de lclair
7、ement appliquer aux caractristiques I-V mesures (CEI 60891:2009) Verfahren zur Umrechung von gemessenen Strom-Spannungs-Kennlinien von photovoltaischen Bauelementen auf andere Temperaturen und Bestrahlungsstrken (IEC 60891:2009) This European Standard was approved by CENELEC on 2010-03-01. CENELEC m
8、embers 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 applic
9、ation 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 Secretaria
10、t has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
11、 the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 60891:2010EN 60891:2010 - 2 - Foreword The text of document 82/581/FDIS, future edition 2 of IEC 60891, prepared by IEC TC 82, Solar photovoltaic energy systems, was subm
12、itted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60891 on 2010-03-01. This European Standard supersedes EN 60891:1994. The main technical changes with regard to the EN 60891:1994 are as follows: extends existing translation procedure to irradiance change during I-V measuremen
13、t; adds 2 new translation procedures; revises procedure for determination of temperature coefficients to include PV modules; defines new procedure for determination of internal series resistance; defines new procedure for determination of curve correction factor. Attention is drawn to the possibilit
14、y that some of the elements of this document may be the subject of patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent rights. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an iden
15、tical national standard or by endorsement (dop) 2010-12-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2013-03-01 Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 60891:2009 was approved by CENELEC
16、as a European Standard without any modification. In the official version, for Bibliography, the following note has to be added for the standard indicated: IEC 60904-5 NOTE Harmonized as EN 60904-5. _ BS EN 60891:2010- 3 - EN 60891:2010 Annex ZA (normative) Normative references to international publi
17、cations with their corresponding European publications The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) app
18、lies. NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60904-1 - Photovoltaic devices - Part 1: Measurement of photovoltaic current-voltage characteristics EN 60904-1 - IEC 60904-2
19、- Photovoltaic devices - Part 2: Requirements for reference solar devices EN 60904-2 - IEC 60904-7 - Photovoltaic devices - Part 7: Computation of the spectral mismatch correction for measurements of photovoltaic devices EN 60904-7 - IEC 60904-9 - Photovoltaic devices - Part 9: Solar simulator perfo
20、rmance requirements EN 60904-9 - IEC 60904-10 - Photovoltaic devices - Part 10: Methods of linearity measurement EN 60904-10 - BS EN 60891:2010 2 60891 IEC:2009 CONTENTS 1 Scope.5 2 Normative references .5 3 Correction procedures 5 3.1 General .5 3.2 Correction procedure 16 3.3 Correction procedure
21、27 3.4 Correction procedure 38 4 Determination of temperature coefficients.13 4.1 General .13 4.2 Apparatus13 4.3 Procedure in natural sunlight.14 4.4 Procedure with a solar simulator .15 4.5 Calculation of temperature coefficients15 5 Determination of internal series resistance RSand RS.15 5.1 Gene
22、ral .15 5.2 Correction procedure 116 5.3 Correction procedure 217 6 Determination of the curve correction factor and 18 6.1 General .18 6.2 Procedure .18 7 Reporting .19 Bibliography21 Figure 1 Example of the correction of the I-V characteristics by Equations (6) and (7) .10 Figure 2 Schematic diagr
23、am of the relation of G3and T3which can be chosen in the simultaneous correction for irradiance and temperature, for a fixed set of T1, G1, T2, and G2by Equations (8) and (9)11 Figure 3 Schematic diagram of the processes for correcting the I-V characteristics to various ranges of irradiance and temp
24、erature based on three measured characteristics 12 Figure 4 Schematic diagram of the processes for correcting the I-V characteristics to various ranges of irradiance and temperature based on four measured characteristics .13 Figure 5 Positions for measuring the temperature of the test module behind
25、the cells 14 Figure 6 Determination of internal series resistance.16 Figure 7 Determination of VOCirradiance correction factor and internal series resistance.18 Figure 8 Determination of curve correction factor.19 BS EN 60891:201060891 IEC:2009 5 PHOTOVOLTAIC DEVICES PROCEDURES FOR TEMPERATURE AND I
26、RRADIANCE CORRECTIONS TO MEASURED I-V CHARACTERISTICS 1 Scope This standard defines procedures to be followed for temperature and irradiance corrections to the measured I-V (current-voltage) characteristics of photovoltaic devices. It also defines the procedures used to determine factors relevant fo
27、r these corrections. Requirements for I-V measurement of photovoltaic devices are laid down in IEC 60904-1. NOTE 1 The photovoltaic devices include a single solar cell with or without a protective cover, a sub-assembly of solar cells, or a module. A different set of relevant parameters for I-V corre
28、ction applies for each type of device. Although 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
29、a module or subassembly of cells. NOTE 2 The term “test specimen” is used to denote any of these devices. NOTE 3 Care should be taken regarding the use of I-V correction parameters. The parameters are valid for the PV device for which they have been measured. Variations may occur within a production
30、 lot or the type class. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IE
31、C 60904-1, Photovoltaic devices Part 1: Measurements of photovoltaic current-voltage characteristics IEC 60904-2, Photovoltaic devices Part 2: Requirements for reference solar devices IEC 60904-7, Photovoltaic devices Part 7: Computation of the spectral mismatch correction for measurements of photov
32、oltaic devices IEC 60904-9, Photovoltaic devices Part 9: Solar simulator performance requirements IEC 60904-10, Photovoltaic devices Part 10: Methods of linearity measurement 3 Correction procedures 3.1 General Three procedures for correcting measured current-voltage characteristics to other conditi
33、ons of temperature and irradiance (such as STC) can be applied. The first is identical to the procedure given in Edition 1 of this standard, but the equation has been rewritten for easier understanding. The second procedure is an alternative algebraic correction method which yields better results fo
34、r large irradiance corrections (20 %). Both procedures require that correction parameters of the PV device are known. If not known they need to be determined prior to performing the correction. The third procedure is an interpolation method which does not require correction parameters as input: It c
35、an be applied when a minimum of three current-voltage curves have been measured for the test device. These three current-voltage curves span the temperature and irradiance range for which the correction method is applicable. BS EN 60891:2010 6 60891 IEC:2009 All methods are applicable to linear devi
36、ces as defined in IEC 60904-10. NOTE 1 An estimate on the translation accuracy is required (see Clause 7). NOTE 2 All PV devices should be linear within a limited range of irradiances and device temperature. Details are described in IEC 61853-1. Common to all procedures is that I-V characteristics o
37、f the PV device are to be measured in accordance with IEC 60904-1. Usually irradiance Gshall be calculated from the measured short circuit current (IRC) of the PV reference device as defined in IEC 60904-2, and its calibration value at STC (IRC,STC). A correction should be applied to account for the
38、 temperature of the reference device TRCusing the specified relative temperature coefficient of the reference device (1/C) which is given at 25 C and 1 000 W/m2. ()C251Wm0001RCRCSTCRC,RC2=TIIG The PV reference device shall either be spectrally matched to the test specimen, or a spectral mismatch cor
39、rection shall be performed in conformance with IEC 60904-7. The reference device shall be linear in short-circuit current, as defined in IEC 60904-10 over the irradiance range of interest. 3.2 Correction procedure 1 The measured current-voltage characteristic shall be corrected to standard test cond
40、itions or other selected temperature and irradiance values by applying the following equations: ()1212SC121 TTGGIII += (1) () ()()121221212TTTTIIIRVVS+= (2) where: I1, V1are coordinates of points on the measured characteristics; I2, V2 are coordinates of the corresponding points on the corrected cha
41、racteristic; G1is the irradiance measured with the reference device; G2is the irradiance at the standard or other desired irradiance; T1is the measured temperature of the test specimen; T2is the standard or other desired temperature; ISCis the measured short-circuit current of the test specimen at G
42、1and T1; and are the current and voltage temperature coefficients of the test specimen in the standard or target irradiance for correction and within the temperature range of interest; RSis the internal series resistance of the test specimen; is a curve correction factor. BS EN 60891:201060891 IEC:2
43、009 7 NOTE 1 As the data point Voc1will be shifted off the current axis when translating from lower to higher irradiance, the translated Voc2has to be determined by linear extrapolation from at least 3 data points near and below Voc1or the original IV curve has to be measured sufficiently far beyond
44、 Voc1. NOTE 2 The units of all correction parameters should be consistent. NOTE 3 If the test specimen is a module the cell I-V correction parameters can be derived from the interconnection circuit. These cell parameters may be used to calculate the module I-V correction parameters for other module
45、types using the same cells. NOTE 4 For crystalline silicon PV devices is normally positive and negative. Procedures for determination of the I-V correction parameters of the test specimen are described in sections 4 to 6. Equation (1) is only applicable for I-V curves measured at irradiances which a
46、re constant during the acquisition of the entire I-V curve. For pulsed solar simulators with decaying irradiance or any other kind of irradiance fluctuations during I-V measurement Equation (1) is not applicable as such. In this case, each measured I-V curve has to be corrected to an equivalent I-V
47、curve at constant irradiance which requires an additional scaling factor in front of ISC. For practical reasons this scaling factor is related to the irradiance corresponding to measured ISC. For non-constant irradiance Equation (1) will become the following translation equation. ()1212SCSC1121 TTGG
48、IGGII += (3) where GSCis the irradiance value at the time of ISCmeasurement and 1G is the irradiance measured at time of data acquisition of individual I-V data points. 3.3 Correction procedure 2 This procedure is based on the simplified one-diode model of PV devices. The semi-empirical translation
49、equations contain 5 I-V correction parameters which can be determined by measurement of I-V curves at different temperature and irradiance conditions. Besides the temperature coefficients for short circuit current () and open circuit voltage () an additional temperature coefficient () is commonly used which accounts for changes of the internal series resistance (and fill factor) with temperature.
