In the world of connected and portable devices, rechargeable devices are part of our everyday life. From personal devices such as the cell phone, smartwatch, or wireless headset, to home devices such as vacuum cleaners or video game consoles, we need to ensure that they are properly charged with the designated cable and correct power supply to protect the safety of the device and operatable after charging. We certainly do not want our devices to malfunction after charging.This is even more important for electric vehicles that requires higher power for charging than our portable devices. In recent years, the average battery capacity of new EV models and the maximum DC charging power rose significantly to cater for larger battery packs to enable further drive distance between charges.
With a 43% increase in total EV sales to over 3 million vehicles1, the electric vehicle supply equipment (EVSE) market is projected to grow at a similar pace to support the growing demand and adoption of EVs around the world. Many more electric charging stations are expected in the coming years but are all charging stations, plugs, and cables built to conform to specific ratings and specifications?
Have you ever wondered if charging your EV at a charging station from a new manufacturer during your road trip can severely damage your vehicle because it is not communicating properly with the charger? How do EV manufacturers and EVSE manufacturers and providers ensure secure communication between the charging station and the vehicle in any environment? There are different specifications and frequencies to be considered for vehicle manufacturers to sell their products globally. On top of that, there will be different International Electrotechnical Commission (IEC) standards and international charging standards to be fulfilled.
Overview of Charging Modes and Standards
There are four charging modes defined by IEC 61851. The first three modes deliver alternating current (AC) to the EV on-board charger. However, mode 4 delivers direct current (DC) directly to the battery and bypasses the on-board charger.
- Mode 1: The EV is directly connected to a regular household power outlet. This mode is the simplest possible charging mode and does not support any communication between the EV and the charge point, hence it is prohibited in many countries due to safety concerns.
- Mode 2: Onboard charger converts AC to DC. It uses a special type of charging cable equipped with an in-cable control and protection device. This can be used for private charging, but its public use is subject to restrictions in many countries.
- Mode 3: Utilizes a dedicated EVSE along with the EV on-board charger. AC from the charging station is applied to the on-board circuitry to charge the battery. Several protection functions are employed to guarantee public safety.
- Mode 4: The only charging mode that incorporates an off-board charger with a DC output. The high-power level involved in this mode mandates a higher level of communication and stricter safety features.
The current charging standards are not globally standardized. Some examples of AC and DC charging adapter systems available in the market are shown below.
Standard Bodies and Test Houses Collaborate
Today, the majority of EV and EVSE charging interfaces are tested manually with little standard conformance, certification, or regulation. However, CharIN e.V., an association which speeds the advancement of the Combined Charging System (CCS) as the global standard for battery-powered vehicles, is about to change that with the publication of harmonized compliance and interoperability test specifications. Keysight is a core member of CharIN e.V., and offers expertise in measurement technology and electromagnetic compatibility (EMC) testing. We work alongside with other automotive original equipment manufacturers (OEMs), suppliers, and test houses in the expert focus group providing automated test equipment for different test cases and keeping up with the latest legislative requirements in the automotive industry.
Test houses play a vital role in supporting the OEMs and EVSE network providers to grant them the required certification and accreditation on their product to meet both automotive and electrification standards. A broad spectrum of technology and testing knowledge is required, and test equipment must be upgradeable to test evolving standards.
It is critical to stress the test conditions to the limits using highly automated technology without damaging the vehicle or charging testing under test. The onus is on the test houses to ensure thorough, repeatable, and reliable tests, which at the same time guarantee the safety of their clients’ devices under test, and the test engineers and technicians operating these test labs.
This is why DEKRA, a leading vehicle inspection, homologation, and certification company, has chosen to partner with Keysight to enable the automotive industry to accelerate the interoperability of charging solutions across different standards and interfaces. DEKRA offers end to-end-testing and certification for Electric Vehicles charging infrastructure, including electric vehicles while Keysight offers training and consultancy on the required interoperability testing as well as software upgrades to include new test cases that are added over time. Like Keysight, DEKRA is also a key member of CharIN, and both companies are committed to enabling safe and reliable charging interoperability.
“Partnering with Keysight enables DEKRA to better serve an automotive industry with solutions in an area where the energy grid meets the automotive world,” said Beat Kreuter, vice president of business line product safety testing at DEKRA. “Keysight solutions enable us to improve safety on the road through the use of highly automated testing technology.”
To address the growing e-mobility market and accelerate the launch of new EV and EVSE, DEKRA needed an innovative way to enable automated interoperability testing. The goal was to enhance overall test consistency, quality, and most importantly, to have a harmonized test routine. This allows DEKRA test facilities around to world to provide similar accredited testing and certification using the same test specifications.
Keysight’s Scienlab Charging Discovery System (CDS) offers modular, all-in-one test customizable test solutions for Electric Vehicles and EVSE charging interfaces up to 900 kW charging power. The series comes in Portable, High-Power, and EMC optimized series are used in three different industry use-cases:
- EV test: CDS emulates the EVSE
- EVSE test: CDS emulates the EV
- Man-in-the-middle test to verify the communication between EV and EVSE
Many different test cases must be considered in the test laboratory before certification can be awarded, allowing the Electric Vehicles and EVSE for consumer use. This automated holistic solution provides reliable conformance and interoperability testing for test houses to help EV manufacturers accelerate time-to-market and EVSE providers to expand EV infrastructure rapidly while ensuring product accuracy, safety, and quality. Hopefully, this will boost customer confidence to adopt EVs and use charging stations without fear, just like filling gasoline/diesel in a petrol station in the coming years.