The e-mobility market is evolving at full speed, with the latest European Council confirming the phasing-out of internal combustion engine (ICE) vehicles by 2035. While most charging still happens at home or work, more public charging points with faster chargers are necessary to support the adoption of electric vehicles (EVs) and fight the range anxiety of users. The charging infrastructure must expand to support the growth of the sales of EVs.

Consumers expect to recharge their EVs just as quickly as refilling their ICE vehicles with gasoline or diesel. This technological change means that the charging process needs to be convenient. Consumers should not be worried about EV compatibility with a charging station or electric vehicle supply equipment (EVSE). Charging should be seamless and fast as possible.

DEKRA is a leading vehicle inspection and market leader for end-to-end testing and certification of EVs and EVSEs according to all global charging standards, including Combined Charging System (CCS), CHAdeMO, EVReady, and Open Charge Point Protocol (OCPP). DEKRA’s unique capability includes end-to-end communication and charging performance testing up to 360 kW at any environmental condition, such as exposure to winter and summer temperatures and severe electromagnetic disturbances.

Services for e-mobility are in use for a range of products — from electric vehicles and charging stations to individual battery cells — and from cables to inverters and connectors. These services address safety, EMC, and cybersecurity.

The CharIN e.V. association defines requirements related to the CCS standards as global standards. The association promotes the publication of harmonized conformance and interoperability test specifications for all types of EVs and EVSEs.

Challenges
Safety is an important aspect for EV owners. Proper charging with the designated cable and correct power supply protects the safety of the EVs, charging stations, plugs, and cables. All the EV elements must be operational after charging. In recent years, the average battery capacity of new EV models and the maximum direct current (DC) charging power rose significantly to accommodate larger battery packs to enable further driving distances between charges.

Manufacturers and providers of EV and EVSE need to ensure secure communication between the charging station and the vehicle in any environment. EV manufacturers must meet many specifications and interfaces (inlets and plugs) to sell their products globally. Additionally, there are different IEC and ISO standards.

Figure 1 shows the four EV charging modes defined by IEC 61851. The first three modes deliver alternating current (AC) to the EV onboard charger. However, mode 4 delivers DC to the battery and bypasses the onboard charger. Figure 2 shows that the current charging standards are not globally standardized, and various AC and DC charging adapter systems are available in the market.

Figure 1. Overview of EV charging modes and standards

With the various combination of EV charging modes and different charging adapter systems, it is essential to have standardised conformance, regulation, or certification for EV and EVSE charging interfaces. It is critical to stress the test conditions to the limits using highly automated testing technology without damaging the vehicle or charging station under test.

Figure 2. Examples of AC and DC charging adapter systems

EV/EVSE charging test solutions

Testing the charging process and behavior of EV and charging stations is a complex process, and the international standards for EV charging standards address several aspects, such as safety, performance, and interoperability. The Keysight Scienlab CDS using Keysight test cases addresses all aspects in a highly integrated process. This charging test solution eliminates the need for extensive test setups, and many of the required instruments are in one solution with the required accuracy.

Figure 3. SL1439A TTCN-3 Charging Communication Test Automation Software enables test management, test sequencing, and reporting for additional analysis

The fully equipped CCTS laboratory consists of the following:

Keysight SL1040A Scienlab Charging Discovery System – Portable Series

Keysight SL1047A Scienlab Charging Discovery System – High-Power Series

Keysight SL1041B Scienlab Dynamic DC Emulator – Mid-Power Series

Keysight SL1042A Scienlab Dynamic DC Emulator – High-Power Series

Keysight SL1203A Scienlab Regenerative AC Emulator

Complementary to the EV charging test equipment, the Keysight Scienlab SL1300A test case library – (Charging Discover) operates the system, visualizes measured values, records test sequences, and generates reports. The Keysight SL1300A Scienlab Test Case Library – Charging Discover combined with the The Keysight SL14XXA Test Case Library – TTCN-3 enables you to get valid EV testing results out of the box.

Each library uses a national or international standard that specifies a certain number of detailed test cases with test actions and the expected behavior. Updates for the test cases are ongoing using the feedback from tests performed by DEKRA and CharIN Testivals participants. Release notes communicate the updates.

Integrating test solutions of VERISCO (also a part of Keysight) to the Keysight EV/EVSE charging test portfolio enhances the capability to provide software-centric EV charging solutions to serve EV and EVSE customers with industry-leading interoperability test solutions for the rapidly developing EV charging market, focusing on DC fast charging applications for all major global standards. The CDS High-Power Series already enables high-power charging up to 1,500 V DC and ± 600 A DC to ensure the long-term future of the laboratory to align with future charging test requirements.

Results
DEKRA and Keysight worked closely to validate extensively 180 test cases that are necessary for DC CCS Basic EVSE profile conformance testing and certification. To ensure that the Keysight EV charging solution offers reproducible and reliable tests and measurements, all functions, including current, voltage, and time measurements, undergo extensive testing and validation.

At the end of this process, CharIN recognises Keysight Scienlab Charging Discovery System as a CharIN Conformance Test System (CCTS) and DEKRA as one of the first CCTS test laboratories for conformance testing and interoperability certification of charging stations for EVs and individual product development testing.

Take “Figure 4” (from Page 7) as “Figure 3”

Caption for “Figure 3” - Figure 3: EV/EVSE test expert at DEKRA performing EVSE test using Keysight SL1047A Scienlab CDS – High-Power Series and Keysight Scienlab Dynamic DC Emulator

Figure 3 shows Keysight SL1047A Scienlab CDS – High-Power Series and Keysight Scienlab Dynamic DC Emulator used for full conformance and interoperability testing with an automated workflow, which improves the certification test turnaround time by more than 70%. CharIN focus group experts define and maintain the CharIN conformance tests to enhance the interoperability of DC charging stations and improve the EV charging experience for consumers.

Figure 4. EV / EVSE test expert at DEKRA performing EVSE test using Keysight SL1047A Scienlab CDS – High-Power Series and Keysight Scienlab Dynamic DC Emulator

Article courtesy: Keysight Technologies

Beat Kreuter, VP of Business Line Product Safety Testing, DEKRA

Partnering with Keysight enables DEKRA to better serve the automotive industry
with solutions in an area where the energy grid meets the automotive world. Together with Keysight, we aim to be ready for the next technological advance in bidirectional charging where the EV is delivering grid support services.

Thomas Goetzl, VP & GM, Automotive and Energy Solutions business unit, Keysight
Our goal is to provide comprehensive, future-proof test solutions that help our customers accelerate and improve the time-to-market of their electric vehicle or charging station without compromising performance, quality, and test coverage.