E-Mobility Engineering 019 | In conversation: Stephen Lambert l WAE EVR l Battery case materials focus l Quality control insight l Clipper Automotive Clipper Cab digest l Optimising battery chemistries insight l Powertrain testing focus

May/June 2023 | E-Mobility Engineering 71 Focus | Powertrain testing systems,” its expert explains. “This is particularly crucial in the development of electrified systems, where the integration of software-driven components has increased the need for rigorous testing.” He explains that HiL simulations accelerate product development and reduce risk by replicating real-world conditions in a controlled environment. With the use of physical as well as digital components it is possible to validate performance in a wide range of scenarios. Also, virtual validation speeds up innovation for vehicle developers who need to bring their vehicles to market as quickly as possible without compromising quality, he adds. Electric drives include control electronics that help optimise the vehicle’s performance and, by shaping responses to driver inputs for example, also help refine its brand character, the rotating machinery testing provider says. Model-based testing enables integrated test and simulation in a single validation environment, increasing productivity and providing extra insight into the systems under test, as well as reducing cost and risk. It also maximises the consistency of the tools and methods while providing a highly agile systems engineering environment. Further, it enables attribute-specific evaluation using virtual models, combined virtual-physical models and physical prototypes, the expert integration testing then system integration testing, then system testing and finally acceptance testing. Each testing phase verifies and validates the work done in the corresponding engineering phase on the opposite stroke of the V. “EV powertrain plans cover performance and efficiency, durability, EMC, mechanical and environmental as well as abuse testing,” says the engineering consultancy and services provider. “There is some regulatory testing such as Regulation 85 [R85] for measurement of power, but in general, EV powertrains follow a multi- phase V model for development, which is comparable to their IC engine counterparts.” R85 is a set of provisions for the approval of ICengine and electric drivetrains set out by theUnitedNations EconomicCommission for Europe, and covers themeasurement of net power for both aswell as 30-minutemaximum power for electric drivetrains, which are defined as the controller andmotors. Here, ‘net power’ means the power measured on a test bench at the crankshaft or its equivalent at a specified rpm, under reference atmospheric conditions, and with specified auxiliary devices attached. The ‘30-minute maximum power’ for an electric drivetrain refers to the net maximum power it can deliver at a specified DC voltage over an average of 30 minutes. In hybrids, the IC engine and the electric drive are tested separately under R85. Before they reach the approval testing stage, EDUs are typically split into their two constituent subsystems, the high- speed e-machine and the transmission assembly, the vehicle test and validation services provider explains. These are initially tested and developed in isolation from one another, particularly during the early phases of development. “One of the benefits of separating the subsystems is that it enables accelerated testing to be carried out, for example to prove the durability of the transmission geartrain in isolation from the rest of the system,” the expert from the engineering consultancy and services provider says. “The battery would also initially be tested separately, for safety, performance and durability.” The expert adds that a chassis dyno would then be used to test the complete system, before moving to a track for vehicle-level testing. Once the durability is proven, the drivetrain is put through regulatory testing such as R85, with lithium-ion batteries going through R38.3 to ensure they and their cells are safe for transport, and R100 for covering safety in their intended use in vehicles. Integrating HiL simulation Hardware-in-the-loop (HiL) simulation is now an essential element of modern test facilities, which increasingly use state-of-the-art digital engineering techniques and tools. These help save time and money by linking physical and virtual development, particularly for software, which is now a critical element of the development path for complex electrified systems, according to the engineering consultancy and services provider. “Advanced data management pipelines enable co-simulation of digital models with physical components, allowing for accurate and comprehensive validation of complex UTAC’s electric motor dynamometer can run tests including part failures, efficiency, speeds, torques and impacts (Courtesy of UTAC)