BRITISH STANDARD BS EN 60904 6 1995 Incorporating Amendment No 1 IEC 60904 6 1994 Photovoltaic devices — Part 6 Requirements for reference solar modules The European Standard EN 60904 6 1994, with the[.]
BS EN 60904-6:1995 BRITISH STANDARD Incorporating Amendment No Photovoltaic devices — Part 6: Requirements for reference solar modules The European Standard EN 60904-6:1994, with the incorporation of amendment A1:1998, has the status of a British Standard ?? ? ?????? ???? ??? ??? ?? ???????? ? ?? ? ?? ?? ?? ?????? ? ?? ? ???????? ??? ? ? ? ? ? ? ? ? ? ? IEC 60904-6: 1994 BS EN 60904-6:1995 Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Committee EPL/47, Semiconductors, to Subcommittee EPL/47/3, Optoelectronic Semiconductor devices and LCDs, upon which the following bodies were represented: British Telecommunications plc Federation of the Electronics Industry Ministry of Defence National Supervising Inspectorate (BSI QA) UK Optical Sensors Collaborative Association This British Standard, having been prepared under the direction of the Electrotechnical Sector Board, was published under the authority of the Standards Board and comes into effect on 15 May 1995 © BSI 23 April 2003 Amendments issued since publication The following BSI references relate to the work on this standard: Committee reference EPL/47/3 Draft announced in BSI News May 1994 ISBN 580 24011 Amd No Date Comments 14305 23 April 2003 Revision of Clause BS EN 60904-6:1995 Contents Page Committees responsible Inside front cover National foreword ii Foreword General Description 3 Selection Temperature measurement Electrical connections Calibration Data sheet Marking Care of reference modules 10 A method for calibration of reference modules against a spectrally matched primary reference cell 11 An alternate method for the calibration of reference modules Annex ZA (normative) Other international publications quoted in this standard with the references of the relevant European publications © BSI 23 April 2003 i BS EN 60904-6:1995 National foreword This British Standard has been prepared by Subcommittee EPL/47/3 and is the English language version of EN 60904-6:1994, Photovoltaic devices — Part 6: Requirements for reference solar modules , including amendment A1:1998, published by the European Committee for Electrotechnical Standardization (CENELEC) It is identical with IEC 60904-6:1994, including amendment 1:1998, published by the International Electrotechnical Commission (IEC) Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online This publication does not purport to include all the necessary provisions of a contract Users are responsible for its 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 and a back cover The BSI copyright notice displayed in this document indicates when the document was last issued ii © BSI 23 April 2003 EN 60904-6 November 1994 + A1 EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM April 1998 ICS 31.260 Descriptors: Photovoltaic devices, solar modules, reference solar modules, requirements, calibration English version Photovoltaic devices Part 6: Requirements for reference solar modules (includes amendment A1:1998) (IEC 60904-6:1994 + A1:1998) Dispositifs photovoltaïques Partie 6: Exigences relatives aux modules solaires de référence (inclut l’amendement A1:1998) (CEI 60904-6:1994 + A1:1998) Photovoltaische Einrichtungen Teil 6: Anforderungen an Referenz-Solarmodule (enthält Änderung A1:1998) (IEC 60904-6:1994 + A1:1998) This European Standard was approved by CENELEC on 1994-10-04 and amendment A1 was approved by CENELEC on 1998-04-01 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 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 © 1994 Copyright reserved to CENELEC members Ref No EN 60904-6:1994 + A1:1998 E EN 60904-6:1994 Foreword The text of document 82(CO)76, as prepared by IEC Technical Committee 82: Solar photovoltaic energy systems, was submitted to the IEC-CENELEC parallel vote in March 1994 The reference document was approved by CENELEC as EN 60904-6 on October 1994 The following dates were fixed: — latest date of publication of an identical national standard — latest date of withdrawal of conflicting national standards (dop) 1995-10-01 (dow) 1993-06-01 Annexes designated “normative” are part of the body of the standard In this standard, Annex ZA is normative Foreword to amendment A1 The text of document 82/183/FDIS, future amendment to IEC 60904-6:1994, prepared by IEC TC 82, Solar photovoltaic energy systems, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as amendment A1 to EN 60904-6:1994 on 1998-04-01 The following dates were fixed: — latest date by which the amendment has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 1999-01-01 — latest date by which the national standards conflicting with the amendment have to be withdrawn (dow) 2001-01-01 © BSI 23 April 2003 EN 60904-6:1994 General 1.1 Scope This part of IEC 60904 gives requirements for the selection, packaging, calibration, marking, and care of reference solar modules It is intended to supplement IEC 60904-2 1.2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of IEC 60904 At the time of publication of this standard, the editions indicated were valid All normative documents are subject to revision, and parties to agreements based on this part of IEC 60904 are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below Members of IEC and ISO maintain registers of currently valid International Standards IEC 60891:1987 , Procedures for temperature and irradiance corrections to measured I-V characteristics of crystalline silicon photovoltaic devices IEC 60904-1:1987 , Photovoltaic devices — Part 1: Measurements of photovoltaic current-voltage characteristics IEC 60904-2:1989 , Photovoltaic devices — Part 2: Requirements for reference solar cells IEC/DIS 82(CO)12 , Photovoltaic devices — Part xx: Computation of spectral mismatch error introduced in the testing of a photovoltaic device (future IEC 60904-xx) 1) Description A reference solar module is a specially calibrated module which is used to measure natural or simulated irradiance or set simulator irradiance levels for measuring the performance of other modules having similar spectral response, optical characteristics, dimensions and electrical circuitry Selection A module selected for calibration as a reference module shall meet the following requirements: 1) its photovoltaic characteristics shall be stable (see Clause ); 2) it should not contain by-pass diodes; 3) if it is made from discrete cells, they shall be matched in short-circuit current and fill factor within ±2 %; 4) the short-circuit current of the reference module shall vary linearly with irradiance over the range of interest The use of the reference module shall be restricted to the following: 1) where errors introduced due to spectral response mismatch between the reference module and test modules (i.e., modules to be measured using the reference module for setting the irradiance) are less than ±1 % The spectral mismatch error shall be calculated according to the future standard IEC 60904-xx; 2) where the dimensions, mechanical construction and electrical circuitry of the reference module and test modules correspond sufficiently so as to minimize discrepancies due to simulator non-uniformity, internal reflections or temperature distribution; 3) the short-circuit current of the reference module shall vary linearly with irradiance over the range of interest, as defined in IEC 60904-10 2) 1) 2) At present at the stage of Draft International Standard IEC 60904-10:1998, Photovoltaic devices — Part 10: Methods of linearity measurement © BSI 23 April 2003 EN 60904-6:1994 Temperature measurement Means shall be provided for determining the equivalent cell temperature (ECT), according to the relevant IEC standard to a precision of ±1 °C Electrical connections The electrical connections to the reference module shall be designed to meet the requirements of IEC 60904-1 Calibration Each reference module shall be calibrated in terms of its short-circuit current at standard test conditions (STC) A method of calibrating reference modules is described in Clause 10 The relative spectral response and the temperature coefficient of the short-circuit current of reference modules may be measured directly, or deduced from measurements made on representative encapsulated solar cells as described in the relevant IEC standards Data sheet Each time a reference module is calibrated, the following information shall be recorded on a data sheet: — manufacturer; — model designation; — serial number; — date of manufacture; — type and dimensions of cells; — construction and dimensions of module; — electrical circuit layout; — calibration organization; — site and date of calibration; — calibration method (refer to relevant standards); — primary reference cell identification; — light source description; — parameters for the determination of the equivalent cell temperature (see the relevant IEC standard); — relative spectral response of the module or a representative encapsulated solar cell; — temperature coefficient of short-circuit current; — calibration value of short-circuit current at STC; — estimated uncertainty Marking The reference module shall carry a clear, indelible serial number for cross-reference to its data sheet © BSI 23 April 2003 EN 60904-6:1994 Care of reference modules The front surface of the reference module shall be kept clean and scratch-free It shall be protected against damage, contamination and degradation A reference module exhibiting any defect which might impair its function shall not be used Reference modules shall be recalibrated at least once every 12 months The calibration of a reference module shall be cross-checked against a stable reference module (or cell) at intervals of no more than three months by comparing their short-circuit currents under the same irradiance If there is any change in their current ratios beyond ±1 %, the module(s) shall be recalibrated If the short-circuit current of a reference module has changed by more than % of the initial calibration, the module shall not be used as a reference module 10 A method for calibration of reference modules against a spectrally matched primary reference cell This clause describes a procedure for calibrating a reference module in natural or simulated sunlight against a primary reference cell whose calibration is based on a radiometer or standard detector conforming to the current world radiometric reference (WRR) The spectral response of the primary reference cell, and that of the reference module to be calibrated, should match as closely as possible 10.1 Natural sunlight Calibration in natural sunlight shall be carried out under the following conditions 10.1.1 Clear, sunny weather, with the diffuse irradiance not greater than 25 % of the global irradiance 10.1.2 No observable cloud formations within a 30 ° half-angle cone surrounding the sun 10.1.3 Total irradiance (sun + sky + ground reflection) not less than 800 W·m –2 , as measured by the primary reference cell 10.1.4 Air mass between AM 1,25 and AM 1,75 10.1.5 Radiation sufficiently stable so that the variation in reference cell short-circuit current is less than ±0,5 % over the time taken for a measurement 10.2 Simulator If simulated sunlight is used, the simulator shall be of Class A in accordance with the relevant IEC standard, with the additional requirement that the non-uniformity of irradiance is less than ±1 % 10.3 Test procedure 10.3.1 Before the calibration, measure the relative spectral response and temperature coefficients of short- circuit current of the reference module or a representative encapsulated solar cell using the procedures described in the relevant IEC standards 10.3.2 Mount the primary reference cell and the reference module co-planar and in close proximity on the same mount Connect to the current and temperature measurement instruments Adjust the mount so that the devices are normal to the light source within ±5 ° 10.3.3 Control the cell temperatures of both the primary cell and the module at 25 °C ± °C Where this is not practical, readings of short-circuit currents must be subsequently corrected to 25 °C in accordance with IEC 60891 10.3.4 Record simultaneous readings of the short-circuit currents and temperatures of both primary cell and module 10.3.5 Repeat step 10.3.4 until five successive sets of readings are obtained in which the ratio of short-circuit currents, corrected to 25 °C, does not vary by more than ±1 % 10.3.6 When calibrating in natural sunlight, steps 10.3.2 to 10.3.5 inclusive, must be performed at least twice a day on at least three separate days © BSI 23 April 2003 EN 60904-6:1994 10.3.7 From the acceptable data, calculate the mean ratio: of reference module at 25 °C Isc of primary reference cell at 25 °C Isc 10.3.8 Multiply the calibration value of the primary reference cell by the calculated mean ratio to obtain the calibration value of the reference module 11 An alternate method for the calibration of reference modules This clause describes an extension of the procedure given in Clause 10 for calibrating reference modules This method eliminates the requirement for close spectral response matching between the primary reference cell and the reference module, and is necessary when no spectral match is possible (such as with new module technologies, or when calibrating against a precision pyranometer or an absolute radiometer) This extension is based on calibrating in natural or simulated sunlight, measuring the spectral irradiance of the light source during the calibration, and subsequently correcting for any spectral mismatch between the primary reference cell and the reference module according to IEC 60904-1 Including 10.1 and 10.2 , this procedure, which requires an instrument to measure the relative spectral irradiance (spectroradiometer), is the same as described in 10.3 , with the following changes: 1) In step 10.3.2 , mount the spectroradiometer co-planar and in close proximity to the primary reference cell and reference module 2) Step 10.3.4 has to be carried out as follows: Record simultaneous readings of the short-circuit currents and temperatures of both primary cell and module, and the relative spectral irradiance of the light source 3) Step 10.3.7 has to be carried out as follows: To the acceptable data, apply the spectral mismatch correction factor in accordance with the relevant IEC standard to the measured short-circuit current values of the reference module Assure the use of corresponding data sets for short-circuit current and spectral irradiance NOTE The range of all integrals in the equations of the relevant IEC standard should correspond to the range of the measured spectral irradiance of the light source The resulting short-circuit current value is the Isc of the reference module at 25 °C Calculate the mean ratio: spectrally-corrected Isc of reference module at 25 °C Isc of primary reference cell at 25 °C © BSI 23 April 2003 EN 60904-6:1 994 Annex ZA (normative) Other international publications quoted in this standard with the references of the relevant European publications This European Standard incorporates by dated or undated reference, provisions from other publications These normative references are cited at the appropriate places in the text and the publications are listed hereafter For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision For undated references the latest edition of the publication referred to applies NOTE When the international publication has been modified by CENELEC common modifications, indicated by (mod), the relevant EN/HD applies IEC publication Date 60891 1987 60904-1 1987 60904-2 60904-xx 1989 — * EN Title Procedures for temperature and irradiance corrections to measured I-V characteristics of crystalline silicon photovoltaic devices Photovoltaic devices Part 1: Measurements of photovoltaic current-voltage characteristics Part 2: Requirements for reference solar cells Part xx: Computation of spectral mismatch error introduced in the testing of a photovoltaic device EN/HD Date EN 60904-1 1993 EN 60904-2 — 1993 — EN 60891 * 1994 60891 includes A1:1992 to IEC 60891 © BSI 23 April 2003 BS EN 60904-6:1995 IEC 60904-6: 1994 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 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