Overview - IEC TR 63396:2021 (Noise measurement method on power capacitors)
IEC TR 63396:2021 documents a standardized method to measure sound pressure levels on power capacitor units so that their sound power level can be determined. The technical report applies to shunt capacitor units, AC filter capacitor units for AC systems with nominal voltage of 1 kV and above (50 Hz or 60 Hz), and to DC filter capacitor units. It fills a gap for capacitor-specific acoustic testing (including use in HVDC converter stations) and provides a basis for consistent laboratory and field measurements.
Key topics and technical requirements
The report defines the measurement method and associated requirements, including:
- Power injection conditions: specified current/voltage injection scenarios for shunt, AC filter and DC filter capacitor units to simulate operating conditions.
- Measuring environment: recommended environment considerations for reliable sound pressure measurements.
- Acoustic instrument requirements: characteristics for basic sound level meters and filters referenced to IEC 61672-1 and IEC 61260-1.
- Reference box and measurement surface: definition of a reference parallelepiped enclosing the unit and the measurement surface where microphone positions are located.
- Microphone arrangement: guidance on positions and orientations for microphones to obtain spatial averages (Annex A).
- Calculation methods: procedures to calculate average sound pressure levels on the measurement surface and derive sound power level.
- Uncertainty assessment: measurement of uncertainty and test acceptance criteria (Table 1).
- Reporting: required test report content and typical report format (Annex C), plus example test circuits (Annex B).
Practical applications and users
IEC TR 63396:2021 is intended for:
- Test laboratories performing type tests and routine acoustic checks of power capacitors.
- Manufacturers seeking consistent methods to characterize acoustic emissions during R&D and production verification.
- Power utilities and EPCs evaluating capacitor noise for substation design, particularly for HVDC converter stations and filter banks.
- Acoustic consultants and regulatory bodies assessing environmental noise compliance and mitigation measures at substations.
Practical uses include product development, type approval, site acceptance testing, environmental impact assessment, and equipment selection where noise is a factor.
Related standards (normative references)
Keywords: IEC TR 63396:2021, noise measurement, power capacitors, sound pressure level, sound power level, shunt capacitor, AC filter capacitor, DC filter, HVDC, microphone arrangement, measurement uncertainty.