IEC 60904-7:2008
Photovoltaic devices - Part 7: Computation of the spectral mismatch correction for measurements of photovoltaic devices

Standard No.

IEC 60904-7:2008

Release Date

2008

Published By

International Electrotechnical Commission (IEC)

Status

Be replaced

Replace By

IEC 60904-7:2019 RLV

Latest

IEC 60904-7:2019 RLV

Replace

IEC 82/540/FDIS:2008 IEC 60904-7:1998

Scope

This part of IEC 60904 describes the procedure for correcting the bias error introduced in the testing 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. This 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 between 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, 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 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 this 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 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 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 SR's, the spectral classification of the simulator is not critical for 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.

IEC 60904-7:2008 Referenced Document

• IEC 60891 Photovoltaic devices - Procedures for temperature and irradiance corrections to measured I-V characteristics*， 2021-10-27 Update
• IEC 60904-1 Photovoltaic devices - Part 1: Measurement of photovoltaic current-voltage characteristics*， 2020-09-25 Update
• IEC 60904-2 Photovoltaic devices - Part 2: Requirements for photovoltaic reference devices*， 2023-06-19 Update
• IEC 60904-3 Photovoltaic devices - Part 3: Measurement principles for terrestrial photovoltaic (PV) solar devices with reference spectral irradiance data*， 2019-02-15 Update
• IEC 60904-8 Photovoltaic devices - Part 8: Measurement of spectral responsivity of a photovoltaic (PV) device*， 2014-05-01 Update
• IEC 60904-9 Photovoltaic devices - Part 9: Solar simulator performance requirements*， 2020-09-18 Update
• IEC 61215 Crystalline silicon terrestrial photovoltaic (PV) modules - Design qualification and type approval
• IEC 61646 Thin-film terrestrial photovoltaic (PV) modules - Design qualification and type approval

IEC 60904-7:2008 history

• 0000 IEC 60904-7:2019 RLV
• 2008 IEC 60904-7:2008 Photovoltaic devices - Part 7: Computation of the spectral mismatch correction for measurements of photovoltaic devices
• 1998 IEC 60904-7:1998 Photovoltaic devices - Part 7: Computation of spectral mismatch error introduced in the testing of a photovoltaic device
• 1995 IEC 60904-7:1995 Photovoltaic devices - Part 7: Computation of spectral mismatch error introduced in the testing of a photovoltaic device