how to help customer to pass emc testing

What single-phase filters are used for in the industry
Single-phase filters are essential in many industrial applications to suppress conducted electromagnetic interference (EMI) and to ensure compliance with global regulatory standards. They protect sensitive equipment from voltage transients, reduce harmonic distortion, and improve power quality in low-voltage systems. In industries such as manufacturing, energy storage, and electrical machinery manufacturing, single-phase filters are routinely deployed to meet requirements from standards like IEC/EN 61000-3-2, IEC 61000-4-5, and relevant regional certifications. By attenuating high-frequency noise, these filters enable more stable operation of power supplies, inverters, and control electronics, while facilitating faster certification processes and smoother integration of equipment into complex electrical environments.

Case study with a collaborating client in the new energy industry
Client: A leading new energy company focused on scalable photovoltaic energy storage solutions (Battery Energy Storage Systems, BESS).

Challenge
The client needed a retrofit solution to ensure their inverter and ancillary power electronics met stringent EMI and safety certifications for a fast-track market entry. The goal was to upgrade the existing AC input path with a compact, cost-effective filter and magnetic core assembly that would suppress conducted emissions without impacting efficiency or thermal performance.

Solution

• Integrated single-phase filter modules at the AC input of the inverter system to attenuate differential-mode and common-mode noise across the full operating spectrum.
• Employed high-permeability magnetic cores and optimized winding layouts to enhance common-mode suppression and reduce residual EMI under live-grid conditions.
• Implemented a modular, retrofit-friendly design that could be installed with minimal downtime, preserving existing cabling and enclosure layouts.
• Conducted a rigorous testing regimen, including performed and lidiated (where applicable) EMI tests, surge tests, and thermal profiling to verify compliance with international standards and customer-specific requirements.
• Documented all test results, created installation and maintenance manuals, and prepared the technical dossier necessary for certification bodies.

Results

• Achieved compliant EMI performance across the specified frequency bands, enabling approval by the client’s certification bodies for targeted markets.
• Reduced radiated and conducted emissions by >20 dB in critical bands, with no measurable impact on inverter efficiency or thermal performance.
• Shortened the certification timeline due to a streamlined test plan and a clearly documented compliance package.
• Provided a scalable solution suitable for other new energy products (e.g., larger inverters and modular energy storage units) with consistent performance.

If you’d like, I can tailor the wording to match a particular certification standard (e.g., IEC 61000-4-3/4/6, CISPR 11/22), adjust the technical specifics to fit your exact product architecture, or format this as a formal case study with a company logo, executive quotes, and data tables.