IEC 61850-7-4:2010+AMD1:2020 CSV
Communication networks and systems for power utility automation — Part 7-4: Basic communication structure — Compatible logical node classes and data object classes

Standard No.

IEC 61850-7-4:2010+AMD1:2020 CSV

Release Date

2020

Published By

International Electrotechnical Commission (IEC)  IX  /  IEC

Status

Be replaced 2020-01

Latest

IEC 61850-7-4:2010/AMD1:2020

Introduction

IEC 61850-7-4 Standard Core Architecture and Technology Evolution

IEC 61850-7-4, as a core component of the power automation communication network system, defines the **compatible logical node classes** and **data object classes** for communication between intelligent electronic devices (IEDs). The second edition of this standard (Edition 2.1, 2020-02) integrates the revisions of AMD1:2020 based on the 2010 version, forming the most complete standardized information model currently available.

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Standard Development Background and Technology Evolution Path

The development of the IEC 61850 series of standards stems from the urgent need for **interoperability** in power system automation. Traditional substation automation systems suffer from incompatibility issues in communication protocols between vendors' equipment, leading to complex system integration and high maintenance costs.

The evolution of IEC 61850-7-4 has gone through three key stages:

Case Study of Technological Evolution: From the first edition in 2003 to the second revised edition in 2020, the standard model has expanded from its initial focus on substations to multiple fields such as distributed generation, smart metering, and renewable energy integration. In particular, the 2020 revision, through unified management using a UML model, has achieved automatic generation and maintenance of the standard content, ensuring technical consistency.

Version Stage	Release Time	Core Technical Features	Model Extension Scope
Edition 1.0	2003-05	Basic Logic Node Definition	Substation Automation
Edition 2.0	2010-03	Improved Data Object Model	Feeder Automation
Edition 2.1 (CSV)	2020-02	UML Model Driven, Enhanced Abstract LN	All Power System Domain

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In-depth Analysis of Logical Node Architecture

Chapter 6 of the standard defines a complete logical node architecture, containing 18 functional groups and corresponding abstract logical nodes. This object-oriented design pattern ensures the scalability and consistency of the model.

Design Philosophy of Abstract Logic Nodes (AbstractLNs)

A significant improvement in the 2020 revision is the addition of a parent abstract logical node to each functional LN group, forming a complete object-oriented model. The abstract LN is located at the top of the inheritance hierarchy and defines the common attributes and behaviors of each functional group.

AbstractLNsGroup	Functional Description	Subclass Examples	Key Data Objects
AbstractLNsCommon	Common Basic Functions	DomainLN, StatisticsLN	Mod, Beh, Health
AbstractLNsGroupP	Protection Function Abstraction	ProtectionLN, CurrentProtectionLN	Op, Str, Blk
AbstractLNsGroupM	Measurement Abstraction	EnergyLN, HarmonicsLN	TotWh, Hz, PPV

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Detailed Classification of Functional Logic Node Groups

System Logic Nodes (LNGroupL)

System-level logic nodes provide basic device management and communication functions:

• LPHD: Physical device logic node, containing device health status, manufacturer information, etc.
• LLNO: Logical device logic node, manages common attributes of logical devices
• LGOS: GOOSE subscription management, supports publish/subscribe communication mode
• LSVS: Sample value subscription, used for merging cell data exchange

Protection Function Logic Nodes (LNGroupP)

Contains 33 specific protection function logic nodes, covering the main protection types of the power system:

Protection Type	Logic Node	Function Description	Typical Application
Current Protection	PTOC, PIOC	Time-Delay Overcurrent, Instantaneous Overcurrent Protection	Line, Transformer Protection
Voltage Protection	PTOV, PTUV	Overvoltage, Undervoltage Protection	Bus Voltage Protection
Differential Protection	PDIF	Current Differential Protection	Transformer and Generator Protection
Distance Protection	PDIS	Impedance Measurement Protection	Transmission Line Protection

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Measurement and Metering Logic Node (LNGroupM)

Provides measurement functions for power quality, harmonics, environmental parameters, etc.:

• MMXU: General measurement node, providing basic electrical quantities such as three-phase voltage, current, and power
• MMTR: Three-phase energy metering, supporting forward/reverse active and reactive energy accumulation
• MHAI: Harmonic and interharmonic measurement, compliant with IEC 61000-4-7 Standard
• MFLK: Flicker Measurement, based on IEC 61000-4-15 Flicker Meter Specification

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Data Object Semantics and Enumeration Type Specification

Chapter 7 of the standard defines the **semantic rules** and **enumeration types** of data objects to ensure consistency in data interpretation.

Key Enumeration Type Analysis

Enumeration Type	Application Area	Typical Enumeration Values	Semantic Description
BehaviourModeKind	Behavior Mode	on, off, blocked	Logical Node Running Status
HealthKind	Health Status	Ok, Warning, Alarm	Device Health Status Indicator
PFSignKind	Power Factor Symbol	IEC, EEI	Follow IEC or IEEE notation conventions
TripModeKind	Trip Mode	phsA, phsB, phsC	Protection Trip Phase Selection

Data Semantics Application Case: In the distance protection logic node PDIS, the semantics of the data objects Str (start) and Op (action) clearly distinguish the different states of protection start and output action. This precise semantic definition avoids ambiguity in the understanding of protection logic between different manufacturers' equipment.

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Key Requirements and Technical Specifications for Standard Implementation

Namespace and Version Management

The standard defines a clear namespace identifier: "IEC 61850-7-4:B", version 2007B, release date 2019-10-31. This strict version management ensures compatibility between different versions of the standard.

Code Component Distribution Mechanism

The standard uses the NSD (Namespace Definition) file format to provide code components, including full and lightweight versions:

• Full Version: Contains all LN definitions and related documents, requires purchase of the standard
• Lightweight Version: Contains only LN definitions, can be downloaded free of charge from the IEC website

The code components follow the NSD format defined by IEC 61850-7-7 and are maintained and updated through the IEC TC57 website.

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Compatibility Handling and Backward Compatibility Strategies

Appendix J of the standard details the compatibility requirements between different revisions:

Compatibility Types	Handling Principles	Scope of Impact	Implementation Recommendations
Backward Compatibility	New Version Devices Support Older Version Protocols	Data Object Extensions	Optional Data Object Handling
Forward Compatibility	Older Version Devices Partially Support New Features	Added LN Class	Ignore Unknown Data Objects
Interoperability	Working Together Between Devices of Different Versions	Core Function Set	Following the Least Common Set

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Scheduling Function Modeling Specifications

Appendix K defines the modeling principles for scheduling functions, including:

• FSCC: Scheduling Controller Logical Node
• FSCH: Scheduling Logical Node, supporting complex time scheduling strategies
• Scheduling State Machine: Defines state transitions such as scheduling activation, suspension, and completion
• Priority Management: Priority handling mechanism when multiple scheduling conflicts occur

Scheduling Application Example: In the demand-side response system, FSCC and FSCH work together to achieve time-based load control.

The dispatch controller manages multiple dispatch instances and automatically activates the corresponding dispatch based on the system status, supporting advanced applications such as peak-valley electricity price response and interruptible load management.

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Standard Implementation Recommendations and Best Practices

Equipment Manufacturer Implementation Guidelines

1. Model Consistency Verification: Verify that the device model conforms to the specification using the NSD file provided by the standard
2. Abstract LN Implementation: Correctly inherit the public properties and methods of the abstract LN to ensure the integrity of the model hierarchy
3. Data Object Optional Handling: Explicitly identify the implementation status of optional data objects and provide configuration tool support
4. Enumeration Type Mapping: Establish a precise mapping relationship between internal enumeration values and standard enumeration types

System Integrator Configuration Recommendations

1. SCL Configuration File Verification: Verify the compliance of the SCL configuration file using the standard schema
2. Interoperability Testing: Perform device interoperability testing based on the core function set defined by the standard
3. Version Compatibility Management: Clarify the standard versions supported by each device in the system and formulate upgrade strategies.
4. Extension Model Management: Standardize the use of private extensions to avoid affecting system interoperability.

Application Guidance for Operation and Maintenance Personnel

1. Standardized Status Monitoring: Use standard status quantities such as Health and Beh for device health management.
2. Understanding Protection Function Model: Master the action logic and conditions of protection LNs to improve fault analysis efficiency.
3. Standardized Access to Measurement Data: Obtain electrical quantities through standard data objects and unify the monitoring interface.
4. Standardized Event Logging: Use standard event models for event logging and analysis.

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Future Technology Development Trends

The standard maintenance mode driven by the UML model provides a solid foundation for future expansion:

Technical Direction	Standard Expansion Requirements	Expected Impact	Timeframe
High Proportion of New Energy Integration	Dedicated LN for Inverters and Energy Storage Systems	Enhancing Grid Flexibility	Short-Term (1-3 Years)
Digital Twin Applications	Simulation Model and Real-Time Data Fusion	Improving System Observability	Mid-Term (3-5 Years)
Artificial Intelligence Integration	Standardized Packaging of AI Algorithm Models	Intelligent Decision Support	Long-Term (5+ Years)
5G Communication Applications	Low-Latency, High-Reliability Communication Optimization	Wide-Area Protection and Control	Mid-Term (3-5 Years)

IEC 61850-7-4:2010+AMD1:2020, as the core modeling standard for power automation communication, provides a solid technical foundation for smart grid construction through its comprehensive definition of logical nodes and data objects. With the deepening of the digital transformation of the power system, this standard will continue to evolve, supporting a wider range of application scenarios and technological innovations.