1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI British StandardsWB9423_BSI_StandardColCov_noK_AW:BSI FRONT COVERS 5/9/08 12:55 Page 1Photovoltaic devices Part 7: Computation of the spectral mismatch correction for measurements of photovoltaic dev
2、icesBS EN 60904-7:2009National forewordThis British Standard is the UK implementation of EN 60904-7:2009. It isidentical to IEC 60904-7:2008. It supersedes BS EN 60904-7:1998 which iswithdrawn.The UK participation in its preparation was entrusted to Technical CommitteeGEL/82, Solar photovoltaic ener
3、gy systems.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 2009ISBN 978 0 580 58390 2ICS 27.160Compliance wi
4、th a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of the StandardsPolicy and Strategy Committee on 31 May 2009Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS EN 60904-7:2009EUROPEAN STANDARD EN
5、60904-7 NORME EUROPENNE EUROPISCHE NORM March 2009 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: avenue Marnix 17, B - 1000 Brussels 2009 CENELEC - All rights of ex
6、ploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60904-7:2009 E ICS 27.160 Supersedes EN 60904-7:1998English version Photovoltaic devices - Part 7: Computation of the spectral mismatch correction for measurements of photovoltaic devices (IEC 60904-7:2008) D
7、ispositifs photovoltaques - Partie 7: Calcul de la correction de dsadaptation des rponses spectrales dans les mesures de dispositifs photovoltaques (CEI 60904-7:2008) Photovoltaische Einrichtungen - Teil 7: Berechnung der spektralen Fehlanpassungskorrektion fr Messungen an photovoltaischen Einrichtu
8、ngen (IEC 60904-7:2008) This European Standard was approved by CENELEC on 2009-03-01. 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 li
9、sts 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
10、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, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Ge
11、rmany, 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 60904-7:2009EN 60904-7:2009 - 2 - Foreword The text of document 82/540/FDIS, future
12、edition 3 of IEC 60904-7, prepared by IEC TC 82, Solar photovoltaic energy systems, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60904-7 on 2009-03-01. This European Standard supersedes EN 60904-7:1998. The main changes with respect to EN 60904-7:1998 are listed b
13、elow: the title has been modified in order to better reflect the purpose of the standard (changed from “mismatch error” to “mismatch correction”); formulae are now accompanied by explanatory text; Clause 3 “Description of method” now describes when it is necessary to use the method and when it may n
14、ot be needed. It describes what data must be collected before the mismatch correction can be calculated; Clauses 4, 5 and 6 have been added; the formula for the mismatch correction has been corrected. The following dates were fixed: latest date by which the EN has to be implemented at national level
15、 by publication of an identical national standard or by endorsement (dop) 2009-12-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2012-03-01 Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 60904-7:2
16、008 was approved by CENELEC as a European Standard without any modification. _ BS EN 60904-7:2009- 3 - EN 60904-7:2009 Annex ZA (normative) Normative references to international publications with their corresponding European publications The following referenced documents are indispensable for the a
17、pplication 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. NOTE When an international publication has been modified by common modifications, indicated by (mod), the relev
18、ant EN/HD applies. Publication Year Title EN/HD Year IEC 60891 -1)Procedures for temperature and irradiance corrections to measured I-V characteristics of crystalline silicon photovoltaic devices EN 6089119942)IEC 60904-1 -1)Photovoltaic devices - Part 1: Measurement of photovoltaic current-voltage
19、characteristics EN 60904-1 20062)IEC 60904-2 -1)Photovoltaic devices - Part 2: Requirements for reference solar devices EN 60904-2 20072)IEC 60904-3 -1)Photovoltaic devices - Part 3: Measurement principles for terrestrial photovoltaic (PV) solar devices with reference spectral irradiance data EN 609
20、04-3 20082)IEC 60904-8 -1)Photovoltaic devices - Part 8: Measurement of spectral response of a photovoltaic (PV) device EN 60904-8 19982)IEC 60904-9 -1)Photovoltaic devices - Part 9: Solar simulator performance requirements EN 60904-9 20072)IEC 60904-10 -1)Photovoltaic devices - Part 10: Methods of
21、linearity measurement EN 60904-10 19982)IEC 61215 -1)Crystalline silicon terrestrial photovoltaic (PV) modules - Design qualification and type approval EN 61215 20052)IEC 61646 -1)Thin-film terrestrial photovoltaic (PV) modules - Design qualification and type approval EN 61646 20082)1)Undated refere
22、nce. 2)Valid edition at date of issue. BS EN 60904-7:2009 2 60904-7 IEC:2008 CONTENTS 1 Scope and object5 2 Normative references .5 3 Description of method.6 4 Apparatus.7 5 Determination of spectral response 7 6 Determination of test spectrum .7 7 Determination of the spectral mismatch factor 8 8 R
23、eport 9 Bibliography10 BS EN 60904-7:200960904-7 IEC:2008 5 PHOTOVOLTAIC DEVICES Part 7: Computation of the spectral mismatch correction for measurements of photovoltaic devices 1 Scope and object This part of IEC 60904 describes the procedure for correcting the bias error introduced in the testing
24、of a photovoltaic device, caused by the mismatch between the test spectrum and the reference spectrum and by the mismatch between the spectral responses (SR) of the reference cell and of the test specimen. The procedure applies only to photovoltaic devices linear in SR as defined in IEC 60904-10. Th
25、is procedure is valid for single junction devices but the principle may be extended to cover multijunction devices. The purpose of this standard is to give guidelines for the correction of measurement bias, should there be a mismatch between both the test spectrum and the reference spectrum and betw
26、een the reference device SR and the test specimen SR. Since a PV device has a wavelength-dependent response, its performance is significantly affected by the spectral distribution of the incident radiation, which in natural sunlight varies with several factors such as location, weather, time of year
27、, time of day, orientation of the receiving surface, etc., and with a simulator varies with its type and conditions. If the irradiance is measured with a thermopile-type radiometer (that is not spectrally selective) or with a reference solar cell, the spectral irradiance distribution of the incoming
28、 light must be known to make the necessary corrections to obtain the performance of the PV device under the reference solar spectral distribution defined in IEC 60904-3. If a reference PV device or a thermopile type detector is used to measure the irradiance then, following the procedure given in th
29、is standard, it is possible to calculate the spectral mismatch correction necessary to obtain the short-circuit current of the test PV device under the reference solar spectral irradiance distribution included in Table 1 of IEC 60904-3 or any other reference spectrum. If the reference PV device has
30、the same relative spectral response as the test PV device then the reference device automatically takes into account deviations of the real light spectral distribution from the standard spectral distribution, and no further correction of spectral bias errors is necessary. In this case, location and
31、weather conditions are not critical when the reference device method is used for outdoor performance measurements provided both reference cell and test PV device have the same relative spectral response. Also, for identical relative SRs, the spectral classification of the simulator is not critical f
32、or indoor measurements. If the performance of a PV device is measured using a known spectral irradiance distribution, its short-circuit current at any other spectral irradiance distribution can be computed using the spectral response of the PV test device. 2 Normative references The following refere
33、nced 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. IEC 60891, Procedures for temperature and irradiance corrections to m
34、easured I-V characteristics of crystalline silicon photovoltaic devices BS EN 60904-7:2009 6 60904-7 IEC:2008 IEC 60904-1, Photovoltaic devices Part 1: Measurement of photovoltaic current-voltage characteristics IEC 60904-2, Photovoltaic devices Part 2: Requirements for reference solar devices IEC 6
35、0904-3, Photovoltaic devices Part 3: Measurement principles for terrestrial photovoltaic (PV) solar devices with reference spectral irradiance data IEC 60904-8, Photovoltaic devices Part 8: Measurement of spectral response of a photovoltaic (PV) device IEC 60904-9, Photovoltaic devices Part 9: Solar
36、 simulator performance requirements IEC 60904-10, Photovoltaic devices Part 10 Methods of linearity measurement IEC 61215, Crystalline silicon terrestrial photovoltaic (PV) modules Design qualification and type approval IEC 61646, Thin film terrestrial photovoltaic (PV) modules Design qualification
37、and type approval 3 Description of method For many PV devices, the shape of the I-V characteristic depends on the short-circuit current and the device temperature, but not on the spectrum used to generate the short-circuit current. For these devices, the correction of spectrum mismatch or spectral r
38、esponse mismatch is possible using the following procedure. For other devices, a measurement of the I-V characteristic shall be done using a light source with the appropriate spectrum. A correction is not necessary if either the test spectrum is identical to the reference spectrum (see IEC 60904-3)
39、or if the test specimens relative spectral response is identical to the reference cell relative spectral response. In this case, the reading as obtained from the reference cell specifies which intensity at the reference spectrum will generate the same short-circuit current in the test device as the
40、test spectrum. If there is a mismatch between both spectra and spectral responses then a mismatch correction should be calculated. Due to the mismatch in spectra and spectral responses, the reading of the reference cell (see IEC 60904-2) does not give the intensity of the reference spectrum that gen
41、erates the short-circuit current as measured for the test device. One must determine the effective irradiance of the reference spectrum that generates the same short-circuit current in the test device as generated by the test spectrum at the measured irradiance Gmeas. Geff at ref spectrum = MM Gmeas
42、 (1) where Gmeasis the irradiance as measured by the reference device with its specific spectral response Sref() and MM is the spectral mismatch factor as determined in Clause 7. For a measurement to be referred to the reference spectral irradiance, two correction methods are possible: a) If possibl
43、e, adjust the simulator intensity so that the effective irradiance as determined by equation (1) equals the reference irradiance Gref(e.g. 1 000 W/m2for STC, as defined in IEC 61215 and IEC 61646). That is to say that the simulator intensity as measured by the reference cell using its calibration va
44、lue given for the reference spectrum has to be set to BS EN 60904-7:200960904-7 IEC:2008 7 Gmeas= Gref/MM (2) Thus, the inverse mismatch factor 1/MM gives the degree by which the simulator intensity has to be adjusted, if the device is linear (see IEC 60904-10). Now, the simulator spectrum +at this
45、irradiance with its actual simulator spectrum generates the same short-circuit current as the reference spectrum at the reference intensity. Proceed to measure the I-V characteristic per IEC 60904-1. b) Otherwise, measure the I-V characteristic using the given simulator intensity. Determine the effe
46、ctive irradiance at the reference spectrum using equation (1). Then transfer the I-V characteristic to the reference irradiance using IEC 60891 with the effective irradiance determined from equation (1). Method a) is preferred for simulated sunlight (see IEC 60904-9), as the actual measurement is pe
47、rformed at the correct short-circuit current, minimising non-linearity errors. Method b) is usually chosen for outdoor measurements, if the light intensity cannot be easily controlled. 4 Apparatus 4.1 Spectral response measurement set up according to IEC 60904-8. 4.2 Apparatus for measurement of PV
48、current voltage characteristics according to IEC 60904-1. 4.3 Spectroradiometer capable of measuring the spectral irradiance in the test plane in a spectral range exceeding that of the spectral responses of the reference and test devices. NOTE 1 For example spectroradiometer measurements are describ
49、ed in CIE 63 (1984). NOTE 2 The input head of the spectroradiometer and the test device should have a similar field of view with a similar dependency of the solid angle. 5 Determination of spectral response 5.1 The relative spectral response of the test specimen shall be measured according to IEC 60904-8. 5.2 If not available from the calibration documents, the relative spectral response of the reference device shall be measured according to IEC 60904-8. 6 Determination of test spe
