IEC TS 62257-7-3:2018

Recommendations for renewable energy and hybrid systems for rural electrification - Part 7-3: Generator set - Selection of generator sets for rural electrification systems

IEC TS 62257-7-3:2018(E) specifies the general requirements for the selection, sizing, erection and operation of generator sets in decentralized rural electrification systems. It applies to all low voltage combustion engine electricity generator sets energized by renewable energy such as biomass gasifier or biogas, or fossil fuel such as gasoline or diesel fuel, and designed for supplying electrical power to isolated sites used in systems as described in IEC TS 62257-2. The aim of this document is to provide users with the appropriate guide to select generator sets for using in micropower plant with different configurations and levels of reliability and safety of the equipment during its estimated service lifespan. This document describes the minimum requirement of generator set functionality and safety requirements and does not claim to be an exhaustive instruction manual or design specification.
The main technical changes of this new edition with regard to the previous edition are as follows:
- Increased the voltage and power levels to which this TS applies.
- Added descriptions of four different types of micropower systems and their relevant requirements.

General Information

• Status: Published
• Publication Date: 12-Mar-2018
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• 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: 06-Apr-2018
• Completion Date: 13-Mar-2018

Relations

• Revises: IEC TS 62257-7-3:2008 - Recommendations for small renewable energy and hybrid systems for rural electrification - Part 7-3: Generator set - Selection of generator sets for rural electrification systems
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC TS 62257-7-3 ®
Edition 2.0 2018-03
TECHNICAL
SPECIFICATION
Recommendations for renewable energy and hybrid systems for rural
electrification –
Part 7-3: Generator set – Selection of generator sets for rural electrification
systems
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IEC TS 62257-7-3 ®
Edition 2.0 2018-03
TECHNICAL
SPECIFICATION
Recommendations for renewable energy and hybrid systems for rural

electrification –
Part 7-3: Generator set – Selection of generator sets for rural electrification

systems
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.160 ISBN 978-2-8322-5455-4

– 2 – IEC TS 62257-7-3:2018 © IEC 2018
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 10
3 Terms and definitions . 11
4 Introduction to generator sets . 14
4.1 Generator set system . 14
4.2 Generator set application in rural electrification systems . 14
4.2.1 General. 14
4.2.2 Single generator set (micropower plant Type A) . 14
4.2.3 Multiple generator sets (micropower plant Type B) . 14
4.2.4 Single generator set with a power conditioning sub-system (micropower
plant Type C). 15
4.2.5 Multiple generator sets with multiple power conditioning sub-systems
(micropower plant Type D) . 15
4.3 Resource assessment . 16
5 Selection and erection . 16
5.1 General . 16
5.2 Selection requirements . 17
5.2.1 Power quality. 17
5.2.2 Generator set sizing . 17
5.2.3 Generator set type . 18
5.2.4 Derating factors . 19
5.2.5 Starting system . 19
5.2.6 Control systems . 20
5.2.7 Noise issues . 20
5.2.8 Environmental issues . 20
5.3 Erection . 21
5.3.1 Shipping . 21
5.3.2 Design of the erection site . 21
5.3.3 Installation requirements. 23
6 Safety. 25
6.1 General . 25
6.2 Electrical issues . 25
6.2.1 General requirements . 25
6.2.2 Connection system to the application . 25
6.2.3 Power cables . 26
6.2.4 Neutral system . 26
6.2.5 Earthing . 26
6.2.6 Overcurrent protection . 27
6.2.7 Residual Current Protection Device (RCD) . 27
6.2.8 Isolating devices . 27
6.3 Mechanical issues . 27
6.3.1 Vibration . 27
6.3.2 Protection from mechanical damage . 27
6.3.3 Protection from moving parts . 28
6.4 Thermal issues . 28

6.5 Fire risk . 28
7 Acceptance . 28
7.1 General . 28
7.2 Conformity of the generator set to the identification file . 28
7.3 Conformity of the generator set system to the generator set specification
(GS) . 28
7.4 Acceptance process . 28
7.4.1 Preparation of the generator set for commissioning . 28
7.4.2 Commissioning inspection of the generator set system . 29
7.4.3 Commissioning tests of the generator set system . 29
7.4.4 Test file . 30
8 Operation and maintenance . 30
8.1 Access to the generator set . 30
8.2 Operation process . 30
8.3 Monitoring . 31
8.4 Maintenance schedule. 31
9 Replacement . 31
10 Marking . 32
10.1 General . 32
10.2 Generator set . 32
10.3 Engine . 32
10.4 Alternator . 33
10.5 Shutdown apparatus . 33
11 Documentation . 33
11.1 General . 33
11.2 Installation . 33
11.3 Operation. 34
11.4 Inspection and maintenance . 34
Annex A (informative) Generator set classification criteria . 35
A.1 General . 35
A.2 Functioning mode . 35
A.3 Services provided . 35
A.4 Application classes . 35
A.5 Lifespan . 36
A.6 Generator set components design . 36
A.6.1 Engine . 36
A.6.2 Alternator . 37
A.6.3 Starting systems . 37
A.7 Configuration types . 37
A.8 Installation modes. 38
Annex B (informative) Identification file . 39
B.1 General . 39
B.2 Electrical construction characteristics . 39
B.3 Mechanical construction characteristics . 39
Annex C (informative) Maintenance schedule . 40
Annex D (informative) Example of commissioning records sheet. 41

Figure 1 – General functional configuration of micropower plant in micropower system . 9

– 4 – IEC TS 62257-7-3:2018 © IEC 2018
Figure 2 – Micropower plant Type A: single generator set . 14
Figure 3 – Micropower plant Type B: multiple generator sets in micropower plant . 15
Figure 4 – Micropower plant Type C: single generato
...