1、Designation: E 1362 05Standard Test Method forCalibration of Non-Concentrator Photovoltaic SecondaryReference Cells1This standard is issued under the fixed designation E 1362; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers calibration and characterizationof secondary terrestrial photovoltaic reference cells to
3、 a desiredreference spectral irradiance distribution. The recommendedphysical requirements for these reference cells are described inSpecification E 1040. Reference cells are principally used inthe determination of the electrical performance of a photovol-taic device.1.2 Secondary reference cells ar
4、e calibrated indoors usingsimulated sunlight or outdoors in natural sunlight by referenceto a primary reference cell previously calibrated to the samedesired reference spectral irradiance distribution.1.3 Secondary reference cells calibrated according to thistest method will have the same radiometri
5、c traceability as theof the primary reference cell used for the calibration. There-fore, if the primary reference cell is traceable to the WorldRadiometric Reference (WRR, see Test Method E 816), theresulting secondary reference cell will also be traceable to theWRR.1.4 This test method applies only
6、 to the calibration of aphotovoltaic cell that demonstrates a linear short-circuit currentversus irradiance characteristic over its intended range of use,as defined in Test Method E 1143.1.5 This test method applies only to the calibration of aphotovoltaic cell that has been fabricated using a singl
7、ephotovoltaic junction.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior
8、 to use.2. Referenced Documents2.1 ASTM Standards:2E 490 Solar Constant and Air Mass Zero Solar SpectralIrradiance TablesE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE 772 Terminology Relating to Solar Energy ConversionE 816 Test Method for Calibra
9、tion of Pyrheliometers byComparison to Reference PyrheliometersE 927 Specification for Solar Simulation for TerrestrialPhotovoltaic TestingE 948 Test Method for Electrical Performance of Photovol-taic Cells Using Reference Cells Under Simulated SunlightE 973 Test Method for Determination of the Spec
10、tral Mis-match Parameter Between a Photovoltaic Device and aPhotovoltaic Reference CellE 1021 Test Methods for Measuring Spectral Response ofPhotovoltaic CellsE 1039 Test Method for Calibration and Characterization ofNon-Concentrator Terrestrial Photovoltaic Reference CellsUnder Global IrradiationE
11、1040 Specification for Physical Characteristics of Non-Concentrator Terrestrial Photovoltaic Reference CellsE 1125 Test Method for Calibration of Primary Non-Concentrator Terrestrial Photovoltaic Reference Cells Us-ing a Tabular SpectrumE 1143 Test Method for Determining the Linearity of aPhotovolta
12、ic Device Parameter With Respect to a TestParameterE 1328 Terminology Relating to Photovoltaic Solar EnergyConversionG 173 Tables for Reference Solar Spectral Irradiances:Direct Normal and Hemispherical on 37 Tilted Surface3. Terminology3.1 DefinitionsDefinitions of terms used in this testmethod may
13、 be found in Terminology E 772 and in Terminol-ogy E 1328.3.2 Definitions of Terms Specific to This Standard:3.2.1 cell temperature, C, nthe temperature of the semi-conductor junction of a photovoltaic cell.3.2.2 junction temperature, nsynonym for cell tempera-ture.3.2.3 test light source, na source
14、 of radiant energy usedfor the secondary reference cell calibration.1This test method is under the jurisdiction of ASTM Committee E44 on Solar,Geothermal, and OtherAlternative Energy Sources and is the direct responsibility ofSubcommittee E44.09 on Photovoltaic Electric Power Conversion.Current edit
15、ion approved April 1, 2005. Published May 2005. Originallyapproved in 1995. Last previous edition approved in 1999 as E 1362-99.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informatio
16、n, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.3 Symbols:3.3.1 The following symbols and units are used in this testmethod:Ccalibration constant, Am2W1,Eirradiance
17、, Wm2,Ettotal irradiance, Wm2,Icurrent, A,Ipprimary reference cell short-circuit current, A,Issecondary reference cell short-circuit current, A,Iscshort-circuit current, A,Lcollimator length, m,Mspectral mismatch parameter,ntotal number of data points,rcollimator receiving aperture radius, m,Rcollim
18、ator opening aperture radius, m,Raabsolute spectral response, AW1,Rrrelative spectral response,Sstandard deviation,Ttemperature, C,atemperature coefficient of reference cell, C1,uocollimator opening angle, , andlwavelength, nm or m.3.3.2 Symbolic quantities that are functions of wavelengthappear as
19、X(l).4. Summary of Test Method4.1 The calibration of a secondary photovoltaic referencecell consists of measuring the short-circuit current of the cellunder natural or simulated sunlight using a primary referencecell to measure the incident irradiance. In addition to theshort-circuit current, the re
20、lative spectral response of the cell tobe calibrated and the relative spectral irradiance of the lightsource must be determined. Errors in the short-circuit currentdue to the spectral irradiance of the light source and thespectral response of the primary reference cell are thencorrected by dividing
21、the short-circuit current by the spectralmismatch parameter. Also, if the temperature of the cell is not25 6 1C, the temperature coefficient for the short-circuitcurrent is needed. The list of necessary test methods is asfollows:4.1.1 The spectral response of the cell to be calibrated isdetermined i
22、n accordance with Test Methods E 1021.4.1.2 The cells short-circuit current temperature coefficientis determined experimentally by measuring short-circuit cur-rent at various temperatures and computing the temperaturecoefficient.4.1.3 Linearity of short-circuit current versus irradiance isdetermined
23、 in accordance with Test Method E 1143.4.1.4 The relative spectral distribution of the light source isdetermined using a spectral irradiance measurement instrumentas specified in Test Method E 973.5. Significance and Use5.1 The electrical output of photovoltaic devices is depen-dent on the spectral
24、content of the source illumination and itsintensity. To make accurate measurements of the performanceof photovoltaic devices under a variety of light sources, it isnecessary to account for the error in the short-circuit currentthat occurs if the relative spectral response of the primaryreference cel
25、l is not identical to the spectral response of the cellto be calibrated.Asimilar error occurs if the spectral irradiancedistribution of the test light source is not identical to the desiredreference spectral irradiance distribution. These errors areaccounted for by the spectral mismatch parameter M
26、(TestMethod E 973), a quantitative measure of the error in theshort-circuit current measurement. It is the intent of this testmethod to provide a recognized procedure for calibrating,characterizing, and reporting the calibration data for secondaryphotovoltaic reference cells.5.2 A secondary referenc
27、e cell is calibrated to the samereference spectral irradiance distribution as the primary refer-ence cell used during the calibration. Primary reference cellscan be calibrated by use of Test Method E 1125 or Test MethodE 1039.NOTE 1No standards for calibration of reference cells to the extra-terrest
28、rial spectral irradiance distribution presently exist.5.3 Asecondary reference cell should be recalibrated yearly,or every six months if the cell is in continuous use outdoors.5.4 Recommended physical characteristics of referencecells are provided in Specification E 1040.5.5 Because silicon solar ce
29、lls made on p-type substrates aresusceptible to a loss of Iscupon initial exposure to light, it isrequired that newly manufactured reference cells be lightsoaked at an irradiance level greater than 850 W/m2for2hprior to initial charcterization in Section 7.6. Apparatus6.1 Normal Incidence Tracking P
30、latform (for calibrationsconducted in natural sunlight)A tracking platform used tofollow the sun that holds both the primary reference cell andthe cell to be calibrated. The tracker shall be able to track thesun to within 60.5 during the calibration procedure.6.1.1 When the calibration is performed
31、in direct naturalsunlight, each cell and the spectral irradiance measurement(see 6.7) shall have collimators that meet the requirements ofAnnex A1 of Test Method E 1125.6.1.2 When the calibration is performed in global normalconditions, no significant energy reflected from surroundingbuildings or an
32、y other surfaces in the vicinity of the test standshall be allowed onto the reference cells for the duration of thecalibration period. Care shall be taken to conduct the calibra-tion in a location or manner such that a condition of highground reflectance is avoided. If significant reflection canoccu
33、r, provision shall be made on the tracker to shield thereference cells by the use of a horizon shield. This horizonshield shall consist of a black nonreflecting surface, and shall,as viewed by each reference cell, block the view downwardfrom the local horizon to the lowest extremes of the field ofvi
34、ew.6.2 Solar Simulator A light source that meets the require-ments of a Class A solar simulator in terms of the nonunifor-mity and temporal instability of the total irradiance, and meetsthe requirements of a Class B solar simulator in terms of thespectral distribution of irradiance performance, as s
35、pecified inSpecification E 927.6.3 Temperature Measurement EquipmentAn instrumentor instruments used to measure the cell temperature of both theE1362052primary reference cell and the cell to be calibrated that has aresolution of at least 0.1C, and a total error of less than 61Cof reading.6.3.1 Senso
36、rs used for the temperature measurements mustbe located in a position that minimizes any temperaturegradients between the sensor and the photovoltaic devicejunction.6.4 Current Measurement EquipmentInstruments used tomeasure the Iscof the reference cell to be calibrated and theprimary reference cell
37、 that has a resolution of at least 0.02 % ofthe maximum current encountered, and a total error of less than0.1 % of the maximum current encountered.6.5 Temperature Control Block (optional)A device tomaintain the temperature of the reference cells at 25 6 1C forthe duration of the calibration.6.6 Spe
38、ctral Response Measurement Equipment, as requiredby Test Methods E 1021.6.6.1 The wavelength interval between spectral responsedata points shall be a maximum of 50 nm.6.7 Spectral Irradiance Measurement Equipment,asre-quired by Test Method E 973.7. Characterization7.1 Cells being calibrated shall be
39、 characterized by thefollowing methods:7.1.1 Spectral ResponseDetermine the relative spectralresponse (optionally the absolute spectral response) of the cellto be calibrated in accordance with Test Methods E 1021.7.1.2 Temperature CoeffcientDetermine the temperaturecoefficient, a, of the cell to be
40、calibrated as follows:7.1.2.1 Using the electrical measurement equipment, mea-sure Iscat four or more temperatures over at least a 50Ctemperature range centered around 35C. The irradiance shallbe at least 750 Wm2and less than 1100 Wm2, as measuredwith a second reference cell.7.1.2.2 Divide each valu
41、e of Iscby the normalized instanta-neous irradiance level at the time of each measurement, andplot the resulting data versus measurement temperature.NOTE 2The normalized instantaneous irradiance can be determinedby dividing a reference cells Iscby its calibration constant.7.1.2.3 Determine the tempe
42、rature coefficient by performinga least-squares fit of the data to a straight line. The slope of theline divided by the interpolated Iscvalue at 25C is thetemperature coefficient.7.1.3 LinearityDetermine the short-circuit current versusirradiance linearity of the cell being calibrated in accordancew
43、ith Test Method E 1143 for the irradiance range 750 to 1100Wm2.7.1.3.1 For reference cells that use single-crystal siliconsolar cells, or for reference cells that have been previouslycharacterized, the short-circuit current versus irradiance linear-ity determination is optional.7.1.4 Fill Factor Det
44、ermine the fill factor of the cell to becalibrated from the IV curve of the device, which shall bemeasured in accordance with Test Method E 948.8. Procedure8.1 Mount the primary reference cell and the cell to becalibrated coplanar in close proximity. For natural sunlightmeasurements, orient the cell
45、s to within 60.5 of normal to thesuns direct beam.8.2 Verify that the following test condition requirements aremet:8.2.1 Total Irradiance The total irradiance shall be 750Wm2and 1100 Wm2at the time of the calibration, asmeasured by the primary reference cell.8.2.2 Irradiance StabilityThe irradiance
46、shall be suffi-ciently stable so that variation in the primary reference cellshort-circuit current is less than 61 % during the calibration.8.2.3 Clouds and Haze For natural sunlight measure-ments, the sky must be clear with no observable cloudformations within a 30 half-angle cone surrounding the s
47、un.8.3 Measure the Iscof both the primary reference cell andthe cell being calibrated during the same time period. Duringthis time period, measure the incident spectral irradiance inaccordance with Test Method E 973.NOTE 3For calibrations using solar simulation, it is not necessary tomeasure the spe
48、ctral irradiance at the same time as the short-circuit currentif it has been determined that the average relative spectral irradiance willnot change more than 63 % over any 100-nm wavelength intervalbetween the two measurements.8.4 Measure the temperature of both cells.8.5 Perform 8.2, 8.3, and 8.4
49、at least three times. One datapoint will be obtained for each time 8.2, 8.3, and 8.4 areperformed.9. Calculation of Results9.1 Spectral MismatchDetermine the spectral mismatchparameter M for each data set in accordance with Test MethodE 973.9.1.1 Reject any data points where the spectral mismatchparameter is not 1.00 6 0.20.9.2 Reference Cell Calibration ConstantFor each datapoint, calculate:Ci5IsiMiCpIpi1 2apTpi2 25!1 2asTsi2 25!(1)where the i subscripts refer to the ith data point, the ssubscripts refer to the
