BSI PD IEC/TS 62446-3:2017
$167.15
Photovoltaic (PV) systems. Requirements for testing, documentation and maintenance – Photovoltaic modules and plants. Outdoor infrared thermography
| Published By | Publication Date | Number of Pages |
| BSI | 2017 | 44 |
This part of IEC 62446 defines outdoor thermographic (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 of 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 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 laboratory 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:
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A simplified thermographic inspection. This is a limited inspection 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 abnormalities are provided to aid the inspector.
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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 inspections 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.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 2 | National foreword |
| 4 | CONTENTS |
| 6 | FOREWORD |
| 8 | 1 Scope 2 Normative references |
| 9 | 3 Terms and definitions |
| 11 | 4 Requirements of inspection equipment 4.1 General 4.2 Minimum requirements for IR-cameras used for inspecting PV plants Tables Table 1 – Minimum requirements for IR-cameras |
| 12 | 4.3 Requirements for photo cameras for documentation of the findings 4.4 Requirements for equipment to record the ambient conditions |
| 13 | 5 Inspection procedure 5.1 General Table 2 – Requirements for equipment to recordthe ambient conditions |
| 14 | 5.2 Visual inspection 5.3 Environmental conditions Table 3 – Required inspection conditions |
| 15 | 5.4 Imaging procedure 5.4.1 General 5.4.2 Using fast carriers for IR-camera, e.g. aerial drones |
| 16 | 5.4.3 Emissivity Figures Figure 1 – Impact of camera moving speed |
| 17 | 6 Software for evaluation 7 Evaluation 7.1 General Figure 2 – Dependence of the emissivity ofglass on the angle of view |
| 18 | 7.2 Evaluation of IR images Figure 3 – Examples of influence of wind (left) and cloud movement (right) on observed temperature pattern |
| 19 | 7.3 Thermal abnormalities 7.3.1 General 7.3.2 Classes of abnormalities (CoA) 7.3.3 Abnormalities of PV modules 7.3.4 Abnormalities of other BOS components Table 4 – Allocation in classes of abnormalities |
| 20 | 7.4 Projection of temperature differences to nominal irradiance 7.4.1 General Figure 4 – Example infrared thermograms of a PV string combiner box with cables, contacts, fuses and switches before (left) and after (right) maintenance on a faulty contact |
| 21 | Figure 5 – Graphic representation of the correction factor for temperature differences to nominal irradiance/load conditions as a function of the relative irradiance/load |
| 22 | 7.4.2 Modules Table 5 – Example correction factors for temperature differences to nominal load conditions based on formula above and Figure 5 |
| 23 | 7.4.3 Other BOS components 8 Inspection report |
| 25 | Figure 6 – Example of image reporting |
| 26 | Annex A (normative) Inspection procedure explanations A.1 Geometric resolution of the camera A.2 Angle of view Figure A.1 – Geometric resolution of the IR camera |
| 27 | A.3 Matrix for cell identification Figure A.2 – Angle of view |
| 28 | 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) |
| 29 | Annex B (normative) Qualification of personnel |
| 30 | Annex C (normative) Matrix for thermal abnormalities of PV modules |
| 34 | Annex D (informative) Polygon measurement as a method of evaluation Figure D.1 – Arithmetic mean value by polygon measurement |
| 35 | Figure D.2 – Arithmetic mean and spot value by polygon measurement |
| 36 | Annex E (informative) Beaufort scale Table E.1 – Beaufort scale taken form World Meteorolgical Organization(www.wmo.int) and Royal Meteorological Society (www.rmets.org) |
| 38 | Bibliography |
