1、 IEC TS 62446-3 Edition 1.0 2017-06 TECHNICAL SPECIFICATION Photovoltaic (PV) systems Requirements for testing, documentation and maintenance Part 3: Photovoltaic modules and plants Outdoor infrared thermography IEC TS 62446-3:2017-06(en) colour inside THIS PUBLICATION IS COPYRIGHT PROTECTED Copyrig
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11、rements for testing, documentation and maintenance Part 3: Photovoltaic modules and plants Outdoor infrared thermography INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 27.160 ISBN 978-2-8322-4290-2 Registered trademark of the International Electrotechnical Commission Warning! Make sure that you obtai
12、ned this publication from an authorized distributor. colour inside 2 IEC TS 62446-3:2017 IEC 2017 CONTENTS FOREWORD . 4 1 Scope 6 2 Normative references 6 3 Terms and definitions 7 4 Requirements of inspection equipment 9 4.1 General . 9 4.2 Minimum requirements for IR-cameras used for inspecting PV
13、 plants . 9 4.3 Requirements for photo cameras for documentation of the findings . 10 4.4 Requirements for equipment to record the ambient conditions 10 5 Inspection procedure . 11 5.1 General . 11 5.2 Visual inspection . 12 5.3 Environmental conditions 12 5.4 Imaging procedure 13 5.4.1 General . 13
14、 5.4.2 Using fast carriers for IR-camera, e.g. aerial drones 13 5.4.3 Emissivity 14 6 Software for evaluation 15 7 Evaluation . 15 7.1 General . 15 7.2 Evaluation of IR images 16 7.3 Thermal abnormalities 17 7.3.1 General . 17 7.3.2 Classes of abnormalities (CoA) 17 7.3.3 Abnormalities of PV modules
15、 . 17 7.3.4 Abnormalities of other BOS components 17 7.4 Projection of temperature differences to nominal irradiance 18 7.4.1 General . 18 7.4.2 Modules . 20 7.4.3 Other BOS components . 21 8 Inspection report . 21 (normative) Inspection procedure explanations 24 Annex A A.1 Geometric resolution of
16、the camera 24 A.2 Angle of view 24 A.3 Matrix for cell identification . 25 (normative) Qualification of personnel 27 Annex B(normative) Matrix for thermal abnormalities of PV modules 28 Annex C(informative) Polygon measurement as a method of evaluation 32 Annex D(informative) Beaufort scale . 34 Ann
17、ex E Bibliography 36 Figure 1 Impact of camera moving speed . 14 Figure 2 Dependence of the emissivity of glass on the angle of view 10 15 Figure 3 Examples of influence of wind (left) and cloud movement (right) on observed temperature pattern . 16 IEC TS 62446-3:2017 IEC 2017 3 Figure 4 Example inf
18、rared thermograms of a PV string combiner box with cables, contacts, fuses and switches before (left) and after (right) maintenance on a faulty contact 18 Figure 5 Graphic representation of the correction factor for temperature differences to nominal irradiance/load conditions as a function of the r
19、elative irradiance/load 19 Figure 6 Example of image reporting 23 Figure A.1 Geometric resolution of the IR camera 24 Figure A.2 Angle of view 25 Figure A.3 View for the designation of cell position, viewed from the front of a 60- cell module, with the junction box at the top (rear side) 26 Figure D
20、.1 Arithmetic mean value by polygon measurement 32 Figure D.2 Arithmetic mean and spot value by polygon measurement . 33 Table 1 Minimum requirements for IR-cameras 9 Table 2 Requirements for equipment to record the ambient conditions 11 Table 3 Required inspection conditions 12 Table 4 Allocation i
21、n classes of abnormalities 17 Table 5 Example correction factors for temperature differences to nominal load conditions based on formula above and Figure 5 . 20 Table E.1 Beaufort scale taken form World Meteorolgical Organization (www.wmo.int) and Royal Meteorological Society (www.rmets.org) . 34 4
22、IEC TS 62446-3:2017 IEC 2017 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ PHOTOVOLTAIC (PV) SYSTEMS REQUIREMENTS FOR TESTING, DOCUMENTATION AND MAINTENANCE Part 3: Photovoltaic modules and plants Outdoor infrared thermography FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldw
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35、ecifications are subject to review within three years of publication to decide whether they can be transformed into International Standards. IEC TS 62446-3, which is a technical specification, has been prepared by IEC technical committee 82: Solar photovoltaic energy systems. IEC TS 62446-3:2017 IEC
36、 2017 5 The text of this technical specification is based on the following documents: Enquiry draft Report on voting 82/1188/DTS 82/1242A/RVDTS Full information on the voting for the approval of this technical specification can be found in the report on voting indicated in the above table. This docu
37、ment has been drafted in accordance with the ISO/IEC Directives, Part 2. A list of all parts in the IEC 62446 series, published under the general title Photovoltaic (PV) systems Requirements for testing, documentation and maintenance, can be found on the IEC website. The committee has decided that t
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40、should therefore print this document using a colour printer. 6 IEC TS 62446-3:2017 IEC 2017 PHOTOVOLTAIC (PV) SYSTEMS REQUIREMENTS FOR TESTING, DOCUMENTATION AND MAINTENANCE Part 3: Photovoltaic modules and plants Outdoor infrared thermography 1 Scope This part of IEC 62446 defines outdoor thermogra
41、phic (infrared) inspection of PV modules and plants in operation. The inspection can include cables, contacts, fuses, switches, inverters, and batteries. This inspection supports the preventive maintenance for fire protection, the availability of the system for power production, and the inspection o
42、f the quality of the PV modules. Included in this document are the requirements for the measurement equipment, ambient conditions, inspection procedure, inspection report, personnel qualification and a matrix for thermal abnormalities as a guideline for the inspection. This document defines outdoor
43、thermography on photovoltaic (PV) modules and Balance-of- system (BOS) components of PV power plants in operation, using passive techniques (standard system operating conditions under natural sunlight, without any external power or irradiation sources). IEC 60904-12-1 covers general methods for labo
44、ratory or production-line PV module thermographic imaging but not the specific details that are most relevant to outdoor imaging of operational power plants including BOS components. Two different levels of inspections are currently used: a) A simplified thermographic inspection. This is a limited i
45、nspection to verify that the PV modules and BOS components are functioning, with reduced requirements for the qualification of personnel. For example, during a basic commissioning of a PV plant. Authoritative conclusions regarding module quality are not possible with this inspection, and examples of
46、 abnormalities are provided to aid the inspector. b) A detailed thermographic inspection and analysis. This may include thermal signatures which differ from the examples provided, and therefore requires a deeper understanding of the thermal abnormalities. For example, it may be used for periodic ins
47、pections according to the IEC 62446 series and for trouble-shooting the cause of underperforming systems. Absolute temperature measurements may be made. An authorized expert in PV plants, together with thermography experts can perform the inspection. 2 Normative references The following documents ar
48、e referred to in the text in such a way that some or all of their content constitutes requirements 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 60050-131, Internat
49、ional Electrotechnical Vocabulary Part 131: Circuit theory IEC 60216-2, Electrical insulating materials Thermal endurance properties Part 2: Determination of thermal endurance properties of electrical insulating materials Choice of test criteria IEC 60216-5, Electrical insulating materials Thermal endurance properties Part 5: Determination of relative thermal endurance index (RTE) of an insulating material IEC TS 62446-3:2017 IEC 2017 7 IEC 6