IEC IEEE 60255-118-1-2018 PDF

Full title and description

IEC/IEEE 60255-118-1:2018 — Measuring relays and protection equipment — Part 118-1: Synchrophasor for power systems — Measurements. This joint IEC/IEEE international standard defines synchronized phasor (synchrophasor), frequency and rate-of-change-of-frequency (ROCOF) measurements, time-tagging and synchronization requirements, evaluation and performance requirements under both steady-state and dynamic conditions, and the definition/requirements of a phasor measurement unit (PMU). It does not prescribe hardware, software or the internal algorithm used to compute phasors, frequency or ROCOF.

Abstract

IEC/IEEE 60255-118-1:2018 provides measurement definitions, timing and synchronization requirements, performance evaluation methods and conformance requirements for synchrophasor measurement systems used in power system monitoring, protection and control. It is intended to ensure consistent, comparable phasor, frequency and ROCOF measurements from PMUs across different vendors and operating conditions (static and dynamic).

General information

• Status: Active / current international standard (joint IEC/IEEE publication), superseding IEEE C37.118.1-2011.
• Publication date: December 2018 (published by IEC 17 Dec 2018; IEEE lists publication 19 Dec 2018).
• Publisher: Joint publication by the International Electrotechnical Commission (IEC) and the Institute of Electrical and Electronics Engineers (IEEE).
• ICS / categories: 29.120.70 (Relays / measuring relays and protection equipment).
• Edition / version: Edition 1.0 (2018).
• Number of pages: 74 pages (official IEC page count; some distributors list slightly different page counts).

Scope

The standard applies to synchronized phasor measurement systems (PMUs) used for measuring AC current and voltage phasors, frequency and ROCOF in electric power systems. It specifies measurement definitions, time-tagging and synchronization accuracy, reporting requirements, test methods and performance criteria for both steady-state and dynamic conditions to enable interoperable, comparable synchrophasor data across equipment and systems. It explicitly does not mandate specific hardware architectures, software implementations or particular phasor computation algorithms.

Key topics and requirements

• Definitions of synchrophasor, frequency and ROCOF and associated measurement units and reference conventions.
• Time-tagging and synchronization requirements (accuracy and tolerance for timestamps used by PMUs).
• Performance requirements for phasor, frequency and ROCOF measurements under steady-state and dynamic conditions, including error limits and test conditions.
• Reference test methods and conformance/evaluation procedures for PMU electrical performance.
• Definition of PMU functional requirements (stand‑alone physical PMU or PMU function within other equipment).
• Guidance on reporting formats and data items required for measured phasors and associated metadata (timing, quality indicators).

Typical use and users

Utilities, transmission system operators, protection and control engineers, PMU and relay manufacturers, testing laboratories, and researchers use this standard to specify, design, verify and test PMUs and synchrophasor measurement systems for power system monitoring, wide-area measurement, protection and control applications. It is commonly referenced in procurement specifications and interoperability testing programs.

Related standards

IEEE C37.118.1-2011 and IEEE C37.118.1a-2014 (earlier IEEE measurement standard and amendment) were superseded by the joint IEC/IEEE 60255-118-1:2018. The companion communications and data format standard historically associated with the synchrophasor family is IEEE C37.118.2 (and related communications/profile standards); updates to communications-related standards and profiles continue to evolve to maintain interoperability. Test suite specifications and industry guides (for example IEEE/IEC test suites and smart‑grid interoperability documents) reference and implement the electrical performance requirements of 60255-118-1:2018.

Keywords

synchrophasor, PMU, phasor measurement unit, ROCOF, frequency measurement, time synchronization, GPS time-tagging, phasor measurement, power system monitoring, PMU testing, IEC/IEEE 60255-118-1.

FAQ

Q: What is this standard?

A: IEC/IEEE 60255-118-1:2018 is a joint IEC and IEEE international standard that specifies measurement definitions and performance requirements for synchrophasor (phasor), frequency and ROCOF measurements produced by PMUs for power systems.

Q: What does it cover?

A: It covers definitions, timing/synchronization requirements, measurement performance and evaluation/test methods for phasor, frequency and ROCOF measurements under steady-state and dynamic conditions, plus PMU functional definitions and reporting metadata — but it does not prescribe internal hardware or software algorithms.

Q: Who typically uses it?

A: Transmission and distribution utilities, system operators, relay and PMU manufacturers, test laboratories, consultants and researchers use it for specifying, procuring, verifying and testing PMUs and synchrophasor systems.

Q: Is it current or superseded?

A: As published in December 2018, IEC/IEEE 60255-118-1:2018 superseded the earlier IEEE C37.118.1 family (2011 and the 2014 amendment) for measurement requirements and is the current measurement standard; users should check for any later amendments or revisions and for companion communications standards updates. IEC lists a stability date through 2028 for this edition.

Q: Is it part of a series?

A: Yes. It is Part 118-1 of IEC 60255 (measuring relays and protection equipment). The broader synchrophasor family includes companion documents addressing communications, data formats and test suites (for example IEEE/C37.118.2 or related communication/profile standards and IEEE test-suite specifications that reference 60255-118-1 electrical requirements).

Q: What are the key keywords?

A: Synchrophasor, PMU, phasor measurement, ROCOF, frequency measurement, time tagging, synchronization, PMU testing, IEEE, IEC.