Article High-Voltage Testing for E-Mobility

The importance of innovative high-voltage testing approaches for the promotion of safe future e-mobility solutions

The crucial role of high-voltage component safety

The crucial role of high-voltage component safety

A shift from high-voltage to high-performance testing approaches

“As the world moves towards e-mobility, the importance of high-voltage components in electric vehicles cannot be overstated. These components are critical to the smooth operation of electric vehicles and must be of high quality, as well as designed to withstand environmental impacts. Innovative test approaches are also required to manage the increased safety challenges of high-voltage components. Offering high-performance testing will therefore be crucial to test intelligent and interconnected components against multiple scenarios.”

Benjamin Sommer

Senior Account Manager

In 2021, the United Nations Climate Change Conference (COP26) identified transport as one of three critical sources of carbon emissions. Consequently, countries, businesses, automotive manufacturers, and other stakeholders signed a declaration of commitment to reach 100% of zero emission vehicle sales by 2040 or earlier. For example, the EU has banned the sale of new cars with combustion engines from 2035.

The good news is that according to the International Energy Agency (IEA)1 the global electric car market is experiencing exponential growth, with sales exceeding 10 million in 2022. This means that 14% of all new cars sold were electric in 2022, up from around 9% in 2021 and less than 5% in 2020. In Europe, electric car sales increased by over 15% in 2022, meaning that more than one in every five cars sold was electric, while the U.S. market increased by 55% in 2022.

The IEA expects electric car sales to continue strongly throughout 2023, as more than 2.3 million were sold in the first quarter, about 25% more than in the same period last year. It predicts sales to total 14 million by the end of 2023, representing a 35% year-on-year increase.

Technology innovation

High-Voltage TestingThe pressure is therefore on for automotive manufacturers to develop new technologies that effectively support these global governmental goals and consumer demand for electric vehicles (EVs). While EV technologies have developed at a pace, the industry’s ability to deliver this transition effectively represents major challenges.

To operate seamlessly and efficiently, electrically powered vehicles can no longer rely on the standard low-voltage (LV) 12-volt electrical systems that are used to power conventional vehicles. Instead, they depend on the use of high-voltage (HV) electrical systems and equipment to generate sufficient energy to power the engine and other essential EV components.

To meet the growing market demand, the automotive industry is focused on speeding up EV development and production, which includes the integration of new and advanced HV technologies into vehicles, such as on-board chargers, HV batteries, DC/DC converters, and E-Motors and DC/AC inverters.

These HV components are critical to the smooth operation of EVs and must be of high quality, as well as designed to withstand the rigours of daily use. However, their higher voltage also brings increased safety risks which must be managed to ensure passenger and operator safety. It's therefore vital that manufacturers prioritise the safety of their HV components and ensure they are designed to meet stringent safety standards.

Testing challenges for HV components

High-Voltage TestingWhile Tier 1 and Tier 2 component manufacturers are focused on accelerating their own development and production processes to meet the demands of integrators, they must also thoroughly test their components in advance to help minimise the risk of failures during the integration process.

However, testing HV systems and equipment to ensure their performance under anticipated operating conditions can present numerous challenges for component manufacturers. This is because HV components are generally far more technically complex than their LV counterparts. Thoroughly testing such sophisticated components requires a more complex testing setup. For example, this may include external power supplies to power a component during testing, software, methods of communicating with the device under test (DUT), and cooling mechanisms to dissipate heat generated during the testing process.

The testing of HV components also requires rigorous project management to help ensure the thoroughness and accuracy of testing. On average, compliance testing of an individual HV component can involve as many as 25 different tests on multiple samples of a single component. The sheer scope of testing activities must therefore be carefully planned and closely managed to provide the accurate data that is required for an objective assessment of critical performance considerations.

Finally, the testing of HV components necessitates in-depth expertise in advanced components. As few component manufacturers currently have the requisite test competency, they are either faced with developing that expertise in-house or identifying third parties that are sufficiently experienced.

High-voltage testing (HVT)

Validation of electric drives plays a central role in ensuring that the drive systems of an EV function reliably. However, voltage peaks of up to 1,000 volts can occur in EV drives. It is therefore crucial that high-voltage systems are handled safely.

Current HV testing approaches concentrate on a specific component in an isolated environment which does not allow any communication between the testing component and the power supply. This means that there is no direct communication with the vehicle (vehicle-communication-infrastructure), for example in terms of CAN-communication. The components are tested in a passive mode, with no simulation of the vehicle situation or environmental issues, with each mode being tested separately.

Exemplary high voltage testing set-up

TÜV SÜD High-Voltage Testing

However, the future of EV technologies necessitates a much more dynamic testing approach to break up the isolated HVT environment into one where more interdependencies between HV components, which are becoming ever more intelligent, are possible.

Moving up a gear to high-performance testing (HPT)

EV technology development is evolving at a rapid pace, with the introduction of intelligent components communicating with each other and the environment, alongside new standards, and requirements within the automotive industry. Increased testing options and flexibility are therefore required for those intelligent and interconnected components to test against multiple scenarios. Customers are also demanding automated test environments that allow the simulation of vehicle communications.

Moving from a HV to a high-performance (HP) testing environment, simulating communication between the components, vehicle and power supply, is therefore important.

In such a high-performance testing approach, an automation system sits at the heart of the testing set-up, communicating with other components and simulating different test situations to which the test component is exposed. At the same time, a cooling system is required as the system under test will experience significant heating during the simulation. Depending on the operation mode, flexible power supplies can be embedded, including several sources and sinks. This will enable control and measurement data acquisition to be carried out in real-time so that the behaviour of the systems under test can be observed in a live environment with actual data. Due to this increased flexibility in HPT systems, individual test conditions and operation modes can be implemented.

Exemplary high-performance test set-up

TÜV SÜD High-Voltage Testing

As part of the HPT service, TÜV SÜD focuses on six intelligent HV items: DC-DC-converter, on-board-charger, e-motor, inverter, cables, battery management system. As all parts are high-voltage and intelligent, effective bus communication is essential.

Driving innovation in EV component testing

For more than 70 years, TÜV SÜD has partnered with major automotive OEMs and component suppliers to develop new technologies. To support global EV innovation, we have made significant investments in testing facilities, advanced equipment and software applications, and technical knowledge, and we are recognised by many in the automotive industry as a world leader in EV and EV component evaluation.

To keep pace with current developments, there is a need for simulation-based and intelligent testing for HV components to ensure the safety of more complex EV technologies. Our TÜV SÜD experts are therefore working intensively to update the HV testing portfolio to include high-performance testing by Q2/2024. Therefore, we are extending our current high-voltage test facilities. This includes investing in new test equipment, such as sources and sinks, measuring systems, automation systems, and a dedicated climate chamber.

Today, we provide traditional HV component testing services in our two state-of-the-art testing laboratories at our German locations Mannheim and Straubing. Having those two laboratory locations allows us to execute different testing requirements in parallel, which significantly reduces project duration for our customers. In addition, we can perform all electrical and environmental tests against the full scope of LV 123, the electrical test standard which verifies the safety and electrical parameters of HV components in vehicles. These tests can all be provided in one location.

Throughout the whole product evaluation and testing process our customers are supported by a dedicated TÜV SÜD project manager, thereby streamlining communication. Our project managers have decades of experience in the automotive industry and dedicate significant time to staying informed about HV technology developments, as well as OEM testing requirements. The result is a unified testing and evaluation process which helps HV component manufacturers meet the rigorous requirements of most global OEMs, allowing them to expand their reach and introduce new and innovative HV technologies to the EV market.

Our team of global experts are always up to date with current global EV market activities, technological trends, and regulations. We are striving to solve any market challenges together with our customers by further developing our testing procedures to meet the demands of new intelligent and connected vehicle technologies. Our mission is to foster the development of future mobility solutions and to enable manufacturers and suppliers to bring their new technologies safely to the road.

Do you want to learn more about TÜV SÜD’s HV component evaluation and testing services, and how we support the growing EV automotive industry?

Get in contact with your experts


International Energy Agency, Global EV Outlook 2023


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