Title: Successful EMC Certification Pass for EV Charging Station with Our Three-Phase Filter

Overview A leading electric vehicle (EV) charging station manufacturer engaged us to help them achieve EMC compliance for a new 43 kW three-phase charging unit. The challenge was to demonstrate robust EMI/EMC performance across multiple firing conditions and ensure the unit met strict regulatory limits in a compact, commercially viable design. Our solution centered on integrating our three-phase filter into the power input stage.

• Customer: EV charging station manufacturer
• Product: 3-phase AC charging unit (up to 43 kW), designed for both commercial and public charging scenarios
• Regulatory goal: Pass EMC testing per relevant standards (e.g., CISPR 22/32, IEC 61000-3-2/-3, depending on region) with margin for production variation

Our Approach

1. Requirements assessment

   • Analyzed the unit’s power topology, cable lengths, and enclosure environment
   • Identified dominant EMI sources: switching noise from the AC-DC converter, rectifier harmonics, and potential radiated emissions through input/output cables

2. Filter selection and customization

   • Recommended our three-phase EMI filter tailored for three-phase 230/400 V input configurations
   • Key features implemented:
     • Attenuation across conducted emissions (common-mode and differential-mode)
     • Adequate inrush current control compatibility
     • Low equivalent series resistance (ESR) and compact form factor for OEM integration
   • Collaborated with the customer to size the filter capacitors and inductors to balance EMC performance with thermal and cost constraints

3. Integration and testing plan

   • Provided detailed mechanical and electrical integration guidelines to ensure proper grounding and shielding
   • Supplied a test-ready reference wiring diagram and placement recommendations inside the enclosure
   • Coordinated with the customer to align the filter installation with the unit’s internal PCB layout to minimize parasitic effects

4. EMC test execution

   • Conducted iterative pre-compliance testing to identify potential hot spots
   • Adjusted filter configuration and routing based on results
   • Performed three full EMC test cycles to verify reproducibility and robustness of the solution

5. Results

   • After three successive tests, the EV charging unit achieved full EMC compliance
   • The filter consistently mitigated both conducted and radiated emissions within the required limits
   • The solution provided stable performance across all tested conditions, with confirmed tolerance to production variations

Benefits Realized

• Reduced time-to-market: Early design-in and iterative testing shortened the path to certification
• Regulatory confidence: Demonstrated robust EMI suppression under multiple test scenarios
• Space and cost efficiency: The compact three-phase filter met the design constraints without requiring downstream redesign

Quote (Paraphrased from a typical customer feedback) “The three-phase filter integration was straightforward, and the testing sequence validated by three consistent passes. The solution delivered the EMC performance we needed with minimal impact on our BOM and layout.”

Next Steps

• Assist with transfer to production, including supplier documentation and test protocol
• Provide ongoing support for any regional EMC variations or future product revisions