IEC TS 62257-7-1:2010

Recommendations for small renewable energy and hybrid systems for rural electrification - Part 7-1: Generators - Photovoltaic generators

IEC/TS 62257-7-1:2010(E) specifies the general requirements for the design and the safety of generators used in decentralized rural electrification systems. Provides requirements for ELV and LV PV arrays. Particular attention must be paid to voltage level, as this is important for safety reasons and has an influence on protective measures and on the skill and ability level of operators. The main technical changes with regard to the previous edition are the following:
- this new version is focused on small PV generators up to 100 kWp;
- it provides case studies.

General Information

• Status: Published
• Publication Date: 28-Sep-2010
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 11.040.50 - Radiographic equipment
• ICS: 27.160 - Solar energy engineering
• Technical Committee: TC 82 - Solar photovoltaic energy systems
• Drafting Committee: JWG 1 - TC 82/JWG 1
• Current Stage: PPUB - Publication issued
• Start Date: 30-Nov-2010
• Completion Date: 29-Sep-2010

Relations

• Revises: IEC TS 62257-7-1:2006 - Recommendations for small renewable energy and hybrid systems for rural electrification - Part 7-1: Generators - Photovoltaic arrays
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC/TS 62257-7-1 ®
Edition 2.0 2010-09
TECHNICAL
SPECIFICATION
colour
inside
Recommendations for small renewable energy and hybrid systems for rural
electrification –
Part 7-1: Generators – Photovoltaic generators

IEC/TS 62257-7-1:2010(E)
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IEC/TS 62257-7-1 ®
Edition 2.0 2010-09
TECHNICAL
SPECIFICATION
colour
inside
Recommendations for small renewable energy and hybrid systems for rural
electrification –
Part 7-1: Generators – Photovoltaic generators

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XC
ICS 27.160 ISBN 978-2-88912-177-9
– 2 – TS 62257-7-1 © IEC:2010(E)
CONTENTS
FOREWORD.6
INTRODUCTION.8
1 Scope.9
2 Normative references .9
3 Terms and definitions .11
4 Design.17
4.1 Electrical design.17
4.1.1 General .17
4.1.2 Earthing system of a IES or a CES including a PV array.18
4.1.3 Extra low voltage segmentation .20
4.1.4 Earthing system.20
4.1.5 Architectures .28
4.1.6 Series-parallel configuration .32
4.1.7 Batteries in systems .32
4.1.8 Considerations due to prospective fault conditions within a PV array.32
4.1.9 Considerations due to operating temperature .32
4.1.10 Component voltage ratings .33
4.1.11 Performance issues .33
4.2 Mechanical design.34
4.2.1 General .34
4.2.2 Thermal aspects .34
4.2.3 Mechanical loads on PV structures .34
4.2.4 Wind.34
4.2.5 Material accumulation on PV array .34
4.2.6 Corrosion .34
5 Safety issues.35
5.1 General .35
5.2 Protection against electric shock and fire .35
5.3 Protection against overcurrent.35
5.3.1 General .35
5.3.2 Overcurrent protection requirements for PV strings .35
5.3.3 Discrimination.36
5.3.4 Overcurrent protection sizing.36
5.3.5 Overcurrent protection location.37
5.4 Protection against effects of lightning and over-voltage .38
5.4.1 General .38
5.4.2 Protection against direct stroke from lightning .38
5.4.3 Protection against over-voltage .39
6 Selection and erection of electrical equipment.40
6.1 Component requirements .40
6.1.1 PV modules .40
6.1.2 PV array and PV sub-array junction boxes.40
6.1.3 Switching devices.40
6.1.4 Cables.41
6.1.5 Protection devices and cables sizing process .43
6.1.6 Plugs, sockets and couplers .44

TS 62257-7-1 © IEC:2010(E) – 3 –
6.1.7 Fuses .44
6.1.8 By-pass diodes.44
6.1.9 Blocking diodes .45
6.2 Location and installation requirements .45
6.2.1 Disconnecting means .45
6.2.2 PV array production optimization .47
6.2.3 Array voltage .48
6.2.4 Wiring system.48
6.2.5 Surge protective devices .51
6.2.6 Earthing arrangement, protective conductors.51
7 Acceptance .51
7.1 General .51
7.2 Conformance with system general specification.51
7.3 Wiring and installation integrity.51
7.3.1 Compliance with wiring standards.51
7.3.2 Compliance with this standard .51
7.4 Open circuit voltage .51
7.4.1 General .51
7.4.2 Procedure.52
7.5 Open circuit voltage measurements for PV arrays with a large number of
strings .52
7.5.1 General .52
7.5.2 Procedure.52
7.5.3 PV arrays and sub-arrays measurement .52
7.6 Short circuit current measurements .53
7.6.1 General .53
7.6.2 Procedure.53
7.7 Commissioning records .54
8 Operation/maintenance .55
8.1 General .55
8.2 Safety .55
8.3 Operation and maintenance procedures .55
9 Replacement .56
10 Marking and documentation.56
10.1 Equipment marking.56
10.2 Requirements for signs.56
10.3 Labelling of PV array and PV sub-array junction boxes.56
10.4 Labelling of disconnection devices .56
10.4.1 General .56
10.4.2 PV array disconnecting device.56
10.5 Fire emergency information signs.56
10.5.1 General .56
10.6 Documentation .57
Annex A (informative) Examples of commissioning records.58
Annex B (informative) Example of maintenance schedule .61
Annex C (informative) Replacement.63
Annex D (informative) Examples of signs.64
Annex E (informative) Case studies .65

– 4 – TS 62257-7-1 © IEC:2010(E)
Annex F (informative) Double switching in PV array.75
Bibliography.81

Figure 1 – General functional configuration of a PV system .18
Figure 2 – Configuration A – PV alone IES P < 500 W – without inverter – d < 15 m .24
Figure 3 – Configuration G – PV alone IES P < 500 W – without inverter – d > 15 m.
...