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

64 May/June 2023 | E-Mobility Engineering The growing shift towards electric and other forms of powertrain is being mirrored by changes in the services from test providers. Peter Donaldson reports Check it out T he state of the market for EV powertrain testing could be seen as buoyant at the moment, as the automotive industry transitions from IC engine test capabilities to those that support new and future propulsion systems centred on electrification and other alternatives to fossil fuels, such as hydrogen. The EU’s ban on the sale of new petrol and diesel cars from 2035 is giving a transformation already under way further impetus and urgency. Vehicle and equipment manufacturers are developing the required test methodologies and capabilities, while service providers are transforming their offerings to support the needs of the new powertrain technologies. One provider of test services for rotatingmachinery reports that it is working almost entirely on fully electric vehicles, and “not even on hybrids any more”. Except for specific industries such as off-highway vehicles, marine and other big transportation vehicles where combustion powertrains remain important, electrification is the preferred method, its expert says. In another shift, a large portion of the market is nowmoving from r&d-related testing to end-of-line testing, as most of the major car manufacturers gear up for large-scale EV production, a provider of variable-speed drives and controls systems for testing EV propulsion says. For the commercial vehicle and off-highway market, they are still investigating the best technologies to take them forward, according to an expert from the company. While the high-level goals of establishing whether components, subsystems and complete powertrains meet their torque and power, efficiency and durability targets are as relevant as ever, NVH measurement requirements are nowmuch more demanding because of the need to identify and characterise multiple sources that are no longer masked by an IC engine, such as road noises, wind and components such as the steering and the battery cooling system. The rotatingmachinery testing expert says testing these new-generation powertrainsmeansmeasuring and evaluating new types of metric. New noise sourcesmust be dealt with, he says, asmust different frequency range and annoyancemetrics, with a strong focus on tonal analysis. Thesemetrics include the tonality hearingmodel, prominence ratio, sharpness and loudness. “This completely reshapes what we used to know as a brand sound signature,” he says. “The growl of a V8 for example, or the smooth feeling of an inline 6 are no longer markers of specific categories of vehicles. “Designing the internal and external sound of EVpowertrains is very important. Electric car userswant to feel comfortable, safe, and to experience a driving feel that corresponds to the type of car they are in.” That means test providers and automotive OEMs have had to broaden their scope to look at every noise source from the powertrain and body as an interacting system. Mahle’s e-drive test facility can accommodate motors and complete e-axles between load machines that reproduce the full range of stresses and strains that would be imposed in service (Courtesy of Mahle)