IEC TS 62257-7-2:2022

IEC TS 62257-7-2 ®
Edition 1.0 2022-03
TECHNICAL
SPECIFICATION
colour
inside
Recommendations for renewable energy and hybrid systems for rural
electrification –
Part 7-2: Generator set – Off-grid wind turbines
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IEC TS 62257-7-2 ®
Edition 1.0 2022-03
TECHNICAL
SPECIFICATION
colour
inside
Recommendations for renewable energy and hybrid systems for rural

electrification –
Part 7-2: Generator set – Off-grid wind turbines

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.180 ISBN 978-2-8322-1087-2

– 2 – IEC TS 62257-7-2:2022 © IEC 2022
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 9
2 Normative references . 10
3 Terms and definitions . 10
4 Symbols and abbreviated terms . 15
4.1 Abbreviated terms . 15
4.2 Symbols . 16
5 Wind turbine (WT) . 16
5.1 Types of wind turbines . 16
5.1.1 Horizontal axis wind turbine (HAWT) . 16
5.1.2 Vertical axis wind turbine (VAWT) . 17
5.1.3 SWT classes. 18
5.2 General characteristics of SWT . 18
5.2.1 Basic technical characteristics . 18
5.2.2 Most important technical characteristics . 19
5.3 Working conditions of SWT . 20
6 Off-grid Small Wind Power Systems (SWPS) . 20
6.1 General . 20
6.2 Major components in SWPS . 20
6.2.1 SWT . 20
6.2.2 Tower . 21
6.2.3 Controller . 22
6.2.4 Brake . 22
6.2.5 Inverter . 23
6.2.6 Storage system . 23
6.2.7 Dump load . 23
6.3 Design Procedure of SWPS . 23
6.3.1 General . 23
6.3.2 Wind resource assessment . 23
6.3.3 Site assessment . 24
6.3.4 Determine the capacity of the SWPS . 24
6.3.5 Select SWT . 24
6.4 Configuration of SWPS . 24
6.4.1 General . 24
6.4.2 Layout SWT(s) on site . 28
7 Selection of SWPS . 28
7.1 General . 28
7.2 Selection criteria . 29
7.2.1 General factors in selection of SWT . 29
7.2.2 Rule of thumb . 29
7.2.3 Wind turbine height . 29
7.2.4 Turbulence . 30
7.3 Design of a microgrid or Isolated Microgrid with SWT . 30
7.3.1 Meet national rural grid standards. 30
7.3.2 Design microgrid and wiring into households . 30

8 Safety issues . 30
8.1 General . 30
8.2 General . 30
8.3 Personal safety . 31
8.3.1 Safety training and regulation following . 31
8.3.2 Basic safety guidelines . 31
8.4 Equipment safety . 32
8.4.1 SWT . 32
8.4.2 System current and voltage . 32
8.4.3 Wiring and disconnection requirements . 32
8.4.4 Grounding. 32
8.4.5 Other safety issues and anti-theft . 33
8.5 SWPS safety for isolated microgrid . 33
8.5.1 System safety . 33
8.5.2 Extreme climate proof . 34
8.5.3 High elevation for electronics . 34
8.6 Protection against electric shock and fire . 34
9 SWT and SWPS installation . 34
9.1 General . 34
9.1.1 Overview . 34
9.1.2 General installation methods . 35
9.1.3 Rooftop installation . 35
9.1.4 Verticality . 35
9.2 Installation of SWPS of isolated microgrid . 36
9.2.1 Transportation . 36
9.2.2 Preparations . 36
9.2.3 Infrastructure . 36
9.2.4 Civil works . 37
9.2.5 Installation of equipment . 38
10 Tests and acceptance . 40
10.1 General . 40
10.2 Individual equipment test . 40
10.3 System self-test . 40
10.4 Acceptance test . 40
10.4.1 General . 40
10.4.2 Preparation . 41
10.4.3 Documentation . 41
10.4.4 Commissioning . 41
10.4.5 Agreement . 42
11 Operation and maintenance . 42
11.1 General . 42
11.2 Safety . 42
11.3 Operation and maintenance procedures . 42
11.4 General inspection, routine and troubleshooting. 43
11.4.1 Inspection . 43
11.4.2 Check list . 43
11.5 Troubleshooting . 43
12 Marking and documentation . 44
...