MEASURING EMC COMPLIANCE

Ensuring EVSE meets safety and performance requirements requires having comprehensive compliance test processes and reliable test and measurement equipment. These are the essentials to measure the causes and impact of electrical noise, enabling engineers to define, debug and circumvent EMI causes and effects. In addition to EVSE circuitry, user interfaces such as touch screens, displays and wireless communication interfaces, such as those used for contactless payment, must be thoroughly tested against both conducted and radiated emissions. To meet these evolving conformance standards and regulations, EVSE manufacturers must plan test capacity and the capability to handle increasing test complexity while planning their design, development and production cycles (see Figure 1).

Figure 1

Figure 1 Capabilities of an EMC test lab. Source: Keysight EMC Test Lab.5

In today’s competitive e-mobility market, EVSE manufacturers must adapt quickly to test a wide range of EVs to ensure their charging products conform to the necessary standards, which differ around the world. In many cases, the EVSE manufacturer does not have access to detailed information about how the EV manufacturer has implemented its controller or if it complies with the published standards. For this reason, a holistic compliance test requires a “synthetic” setup which emulates the real-world environment of a charging station, operates within the appropriate specifications and provides appropriate means of defect detection and analysis. This real-world emulation test environment provides further advantages:

  • A real electric car is not needed in the test lab. The emulator simulates the specifications of different EV models.
  • The charging duration is not restricted, as an electronic load is used instead of a battery with limited capacity.
  • Tests can be fully automated, which is particularly useful with recurring test sequences and large numbers of units, such as with end-of-line testing.

A key consideration for EMC testing in this emulated environment is whether the test equipment itself is properly shielded so it provides “unbiased” measurements necessary for EMC compliance and homologation tests.

The EMC test architecture illustrated in Figure 2 shows an EMC-optimized emulator, the Keysight Scienlab Charging Discovery System (CDS), which is configured in this use case to act as an electric car for testing EVSE. Both the emulator and the EVSE device under test (DUT) are inside an anechoic chamber for the EMC immunity and emission tests of EV charging infrastructure, such as DC fast-charging stations or AC or DC charging.

Figure 2

Figure 2 Test setup for EMC testing of the EVSE. Source: Keysight Scienlab CDS.6

Due to the special EMC shielded design and built-in low noise components, emission from the emulator is reduced to a minimum. This enables EMC testing of EVSE under real charging conditions without environmental interferences. Since the emulator is immune to external electromagnetic fields, it can be placed close to the EVSE DUT during immunity testing.

OUTLOOK

Demand for EMC testing is likely to grow in the coming years, buoyed by market drivers such as faster and higher power charging and the convergence of connected automated driving features on the e-mobility platform. While new conformance standards and regulations may pose challenges for EVSE manufacturers, they have opened opportunities for companies offering EMC testing and certification services. This collaborative approach is a win-win for the industry, allowing EVSE manufacturers to focus on developing and deploying a safe, reliable charging infrastructure as part of building a zero carbon footprint transportation future.

References

  1. C. McKerracher, “EV Charging Data Shows a Widely Divergent Global Path,” Bloomberg, March 2021, Web. www.bloomberg.com/news/articles/2021-03-23/ev-charging-data-shows-a-widely-divergent-global-path.
  2. “FACT SHEET: President Biden Announces Support for the Bipartisan Infrastructure Framework,” The White House, June 2021, Web. www.whitehouse.gov/briefing-room/statements-releases/2021/06/24/fact-sheet-president-biden-announces-support-for-the-bipartisan-infrastructure-framework/.
  3. “Electric cars: No restrictions for patients with pacemakers and defibrillators,” Technical University of Munich, June 2018, Web. www.tum.de/en/global/international-locations/san-francisco-news/news-detail/article/34776/.
  4. “EMC Regulations,” LearnEMC, Web. https://learnemc.com/emc-regulations-and-standards.
  5. “Regulatory Test Test Lab, Böblingen Germany,” Keysight Technologies, Web. www.keysight.com/us/en/products/services/test-as-a-service-taas/emc-test-lab.html.
  6. “SL 1040A Series Scienlab Charging Discovery System (CDS),” Keysight Technologies, Web. www.keysight.com/us/en/products/hev-ev-grid-emulators-and-test-systems/sl1040a-series-scienlab-charging-discovery-system.html.