Overview
IEC TR 62681:2022 - Electromagnetic performance of HVDC overhead transmission lines is a Technical Report that provides general guidance on the electromagnetic environment of high voltage direct current (HVDC) overhead transmission lines. It describes the major parameters used to characterize electromagnetic properties - electric fields, ion current, magnetic fields, radio interference (RI), and audible noise (AN) - and consolidates calculation methods, measurement practice and experimental results to support design and environmental assessment.
Key topics and technical content
- Scope and intent
- Guidance where evaluation methods or criteria are not yet nationally regulated; intended to support electromagnetic design, limit environmental impact, and help optimize engineering costs.
- Physical phenomena
- Descriptions of corona, space charge, static electric fields and ion currents, magnetic field distributions, RI generation mechanisms and audible-noise origins.
- Calculation methods
- Multiple modelling approaches are covered, including semi-analytic methods, finite element methods, BPA method, and empirical approaches (e.g., EPRI, IREQ, CISPR prediction formulas for RI).
- Measurement and experimental data
- Instrumentation, measurement methods and extensive experimental results (annexes) for real HVDC lines (Bonneville, FURNAS, Manitoba Hydro, Hydro-Québec, and others).
- Environmental and human implications
- Discussion of effects of electric fields, space charge and audible noise on people and nature, and national design practices and criteria.
- Audible noise & radio interference
- Lateral profiles, statistical distributions, propagation and empirical/semi-empirical prediction formulas, and national limit examples.
Practical applications and users
This TR is practical for:
- Transmission system designers and HVDC engineers - to select conductor configuration, pole spacing and insulator design considering electromagnetic emissions.
- Utilities and project planners - to assess environmental compliance, public exposure and risk of complaints related to audible noise and radio interference.
- Regulators and environmental assessors - to adopt reference methods and interpret measurement data where local criteria are absent.
- Consultants and researchers - for comparison of calculation methods, modelling best practices and benchmarking against experimental datasets.
Practical uses include electromagnetic design optimization, environmental impact assessment, measurement program development, and cost trade-off analysis between mitigation measures and line configuration.
Related standards and references
- Empirical and prediction methods referenced include EPRI, IREQ, and CISPR formulas for RI. The report complements national regulations and other IEC publications by providing a consolidated technical basis for electromagnetic performance assessment of HVDC overhead lines.
Keywords: IEC TR 62681:2022, HVDC, electromagnetic performance, electric field, ion current, magnetic field, radio interference, audible noise, overhead transmission lines.