IEC TR 61850-90-21:2025

Communication networks and systems for power utility automation - Part 90-21: Travelling Wave Fault Location

IEC TR 61850-90-21:2025, which is a Technical Report, aims to provide background information, use cases, data models and guidance on the application of such a technique.
This document will
1) describe the principles of fault location based on travelling waves aided by communications;
2) specify use cases for this method under the following application scenarios:
a) Single-ended fault location,
b) Double-ended fault location through communications between two devices,
c) Double-ended fault location with communications to a master station,
d) Wide area fault location applications,
e) Pulse radar echo method,
f) Substation integration with other fault location and disturbance recording functions,
g) Testing and calibration;
3) describe the information model for each use case;
4) give guidance on scheme configuration.

General Information

• Status: Published
• Publication Date: 11-Feb-2025
• ICS: 33.200 - Telecontrol. Telemetering
• Technical Committee: TC 57 - Power systems management and associated information exchange
• Current Stage: PPUB - Publication issued
• Start Date: 29-Nov-2024
• Due Date: 12-Feb-2025
• Completion Date: 12-Feb-2025

Standards Content (Sample)

IEC TR 61850-90-21 ®
Edition 1.0 2025-02
TECHNICAL
REPORT
Communication networks and systems for power utility automation –
Part 90-21: Travelling Wave Fault Location

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IEC TR 61850-90-21 ®
Edition 1.0 2025-02
TECHNICAL
REPORT
Communication networks and systems for power utility automation –

Part 90-21: Travelling Wave Fault Location

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.200  ISBN 978-2-8327-0163-8

– 2 – IEC TR 61850-90-21:2025 © IEC 2025
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
1.1 Scope of work . 8
1.2 Published versions of the standard and related namespace names . 8
1.3 Namespace name and version . 8
1.4 Published versions of the standard and related namespace names . 8
1.5 Code Component distribution . 9
2 Normative references . 10
3 Terms and definitions . 10
4 Types of travelling wave fault location . 10
5 Requirements and use cases . 11
5.1 General . 11
5.2 Use case 1: Single-ended fault location (Type A) . 12
5.2.1 Use case 1A: Single-ended fault location (Type A) – phase segregated . 12
5.2.2 Use case 1B: Single-ended fault location (Type A) – 3-phase lines with
modes at different speeds. 18
5.3 Use case 2: Double-ended fault location (Type D) through communications
between two devices . 23
5.3.1 Description of the use case . 23
5.3.2 Diagram of the use case . 25
5.3.3 Technical details . 26
5.3.4 Step by step analysis of the use case . 27
5.3.5 Information exchanged . 29
5.4 Use case 3: Double-ended fault location (Type D) through communications
with a master station . 29
5.4.1 Description of the use case . 29
5.4.2 Diagram of the use case . 31
5.4.3 Technical details . 32
5.4.4 Step by step analysis of the use case . 33
5.4.5 Information exchanged . 35
5.5 Use case 4: Wide area fault location (Type W) . 35
5.5.1 Description of the use case . 35
5.5.2 Diagram of the use case . 37
5.5.3 Technical details . 39
5.5.4 Step by step analysis of the use case . 40
5.5.5 Information exchanged . 43
5.6 Use case 5: Pulse radar echo method (Type C and Type FMCW) . 43
5.6.1 Description of the use case . 43
5.6.2 Diagram of the use case . 45
5.6.3 Technical details . 47
5.6.4 Step by step analysis of the use case . 48
5.6.5 Information exchanged . 50
5.7 Use case 6: Integration with other fault location and disturbance recording
functions in a substation . 50
5.7.1 Description of the use case . 50
5.7.2 Diagram of the use case . 51

5.7.3 Technical details . 52
5.7.4 Step by step analysis of the use case . 53
5.7.5 Information exchanged . 55
5.8 Use case 7: Testing and calibration . 55
5.8.1 Use case 7a: Wave velocity calibration . 55
5.8.2 Use case 7b: Simulation testing by remote commands . 60
5.8.3 Use case 7c: Calibration for the pulse radar echo method . 64
5.9 Use case 8: Fault location for hybrid lines . 68
6 Information models . 69
6.1.1 Mapping of the requirements of use case 1 . 69
6.1.2 Mapping of the requirements of use case 2 . 70
6.1.3 Mapping of the requirements of use case 3 . 71
6.1.4 Mapping of the requirements of use case 4 . 72
6.1.5 Mapping of the requirements of use case 5 . 73
6.1.6 Mapping of the requirements of use case 6 . 74
6.1.7 Mapping of the requirements of use case 7a . 75
6.1.8 Mapping of the requirements of use case 7b . 76
6.1.9 Mapping of the requirements of use case 7c . 77
7 Logical node classes and data objects modelling . 78
7.1 General . 78
7.2 Abbreviated terms used in data object names . 78
7.3 Logical node classes . 78
7.3.1 General . 78
7.3.2 Classes list . 79
7.3.3 Logical nodes for protection related functions of 90-21 (LNGroupR) . 79
7.3.4 Logical nodes for further power system equipment of 90-21 (LNGroupZ) . 86
7.4 Data object name semantics . 91
8 System configuration . 92
8.1 General . 92
8.2 Double-circuit line . 92
8.3 Topology for single line with aerial mode and zero mode . 94
Annex A (normative) Conditions for element presence . 95
Annex B (informative) Explanation of percentage full scale . 97
Bibliography . 98

Figure 1 – Wide-area travelling wave fault location system . 36
Figure 2 – Class diagram LogicalNodes_90_21:LogicalNodes_90_21 . 79
Figure 3 – Class diagram LNGroupR::LNGroupRext. 80
Figure 4 – Class diagram LNGroupZ:LNGroupZext . 86

Table 1 – Published versions of the namespace . 8
Table 2 – Attributes of (Tr)IEC 61850-90-21:2022A namespace . 9
Table 3 – Single-ended fault location use case requirement mapping over LNs. 70
Table 4 – Double-ended fault location through communications between two devices
use case requirement mapping over LNs . 71
Table 5 – Double-ended fault location through master station communications use
case requirement mapping over LNs . 71

– 4 – IEC TR 61850-90-21:2025 © IEC 2025
Table 6 – Wide Area fault location use case requirement mapping over LNs . 72
Table 7 – Pulse radar echo method use case requirement mapping over LNs . 73
Table 8 – Integration with other equipment use case requirement mapping over LNs . 74
Table 9 – Line calibration use case requirement mapping over LNs . 75
Table 10 – Testing by remote commands use case requirement mapping over LNs . 76
Table 11 – Calibration for the pulse radar echo method – use case requirement
mapping over LNs . 77
Table 12 – Normative abbreviations for data object names . 78
Table 13 – List of classes defined in LogicalNodes_90_21 package . 79
Table 14 – List of classes defined in LNGroupR package . 80
Table 15 – Data obje
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