Overview
IEC TS 62001-3:2026 is a technical specification by the International Electrotechnical Commission (IEC) focusing on the specification and design evaluation of AC filters for high-voltage direct current (HVDC) systems, specifically covering modelling aspects. This document provides comprehensive guidance on AC network impedance modelling, dealing with pre-existing harmonics in system performance and rating calculations, and examining harmonic interactions across converters, including cross-modulation effects.
The guidance is primarily targeted at passive AC filter technology and line-commutated converter-based HVDC systems, but much of its content is relevant for voltage source converter (VSC) applications as well. The document addresses modelling of harmonic distortion and audible frequency disturbances, excluding filters intended for power line carrier (PLC) and radio interference frequency ranges.
Key Topics
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AC Network Impedance Modelling
- Discusses defining, representing, and evaluating the harmonic impedance of the AC network as seen by the HVDC converter.
- Highlights the impact of inaccurate network impedance definition on filter design and system performance.
- Provides recommendations for responsibility and methods to ensure consistent specification of network impedance.
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Treatment of Pre-existing Harmonics
- Explores how harmonics present in the AC network before HVDC system integration can affect filter performance and equipment rating.
- Covers techniques for modelling, measuring, and evaluating harmonic levels to ensure compliance with performance standards.
- Offers guidance on incremental and aggregate harmonic performance assessments.
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Harmonic Interaction Across Converters (Cross-Modulation)
- Analyzes active converter behavior and the interaction of harmonics between AC and DC sides.
- Details major modelling approaches to evaluate cross-modulation phenomena and their implications for AC filter design.
- Summarizes study methods, such as time and frequency domain models, to support robust system analysis.
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Frequency Range Considerations
- Focuses on the key frequency range associated with harmonic distortion and audible disturbances.
- Excludes design elements related to PLC and high-frequency radio interference filtering.
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Technical Revisions
- This edition introduces new sections: terms and definitions, an enhanced modelling overview, the rearrangement of core clauses, and an updated bibliography.
Applications
IEC TS 62001-3:2026 is intended for application in specifying, designing, and verifying AC side filters in HVDC projects. Practical uses include:
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Utilities and Consultants
- Providing technical requirements for new HVDC projects.
- Evaluating filter designs and ensuring optimal system integration.
- Preparing tender documentation and assessing bids with consistent impedance modelling standards.
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System Designers and Engineers
- Enhancing simulation accuracy for HVDC filter performance.
- Identifying and mitigating harmonic risks associated with interconnected converter stations.
- Ensuring correct treatment of existing network harmonics during system upgrades or expansions.
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Manufacturers and Project Developers
- Aligning product specifications to comply with prevalent international standards.
- Supporting equipment rating, testing, and quality assurance processes.
By following the guidelines in IEC TS 62001-3:2026, stakeholders can achieve reliable harmonic performance, reduced risk of equipment overload or instability, and extended equipment lifetime in HVDC system deployments.
Related Standards
These related documents provide a comprehensive framework for the specification, simulation, performance assessment, and verification of AC filter solutions in HVDC systems.
Keywords: IEC TS 62001-3:2026, HVDC, AC filter design, network impedance modelling, harmonic performance, cross-modulation, passive filters, VSC, system harmonics, international standards, power quality, converter interaction.