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

Software-defined vehicles While some might still be puzzled at the migration of former race engineers into e-mobility, Lambert echoes similar sentiments to those of Viritech’s Matt Faulks ( EME 17, January/February 2023), and defines Formulas One and E as “essentially competitions in efficiency, with a clear trickle-down of technology from both to applicable areas of the wider automotive sector. “In Formula E, the cars are all the same apart from the driver and drivetrain. Since the energy limit is the same for all the teams, the only way to engineer an advantage is with a more efficient drivetrain. “There are clear parallelswith automotive e-mobility: when theOEMs chase efficiency, theymake better vehicles. They can use a smaller and lighter battery, because they need less onboard energy, whichmeans they get a lighter EV, which further reduces the energy they need, and thatmeans the cooling system required is lighter, and so on.” So, with Tesla’s dominance of the EV market effectively over, and every OEM as well as hundreds of start-ups rushing to release an affordable EV alongside their existing but more expensive models, Lambert anticipates the next evolution in e-mobility to revolve around a grand push for efficiency, particularly with regard to power and energy. “[UK magazine] Autocar carried out a great series of tests to identify which EVs were the most fun to drive, and the driver’s experience is something many engineers forget is actually a huge part of what influences the success of vehicle brands,” he says. “First place was taken by the Porsche Taycan, second was the BMW i40, and the Tesla Model 3 came somewhere in the middle. But the part that was really interesting was that third place was taken by the Kia EV6. “It might sound mad to have a Kia being listed up there with a BMW and a Porsche, but the truth is that Kia – and its parent company Hyundai – have done a great job of chasing efficiency. The EV6 has 800 V SiC power electronics, which means it charges really quickly and its battery doesn’t need to be too big or heavy. It also has a very weight-efficient body and chassis.” He adds that a very fast rate of control typically becomes necessary when integrating SiC power electronics, principally to enable tighter control loops over the inverter and, by extension, the motor. That adds an extra layer of controllability to how the car handles. Given how this improves overall driving experience, Lambert and McLaren Applied anticipate a future trend in electrification (after the push for efficiency) to focus on this subjective but very tangible area, once OEMs catch on to how efficiency makes for a more enjoyable drive. “EVs can give you plenty of speed and torque in a straight line, but other than that, high-performance OEMs are struggling to figure out how to get customers engaged with their cars when there isn’t an IC engine inside,” Lambert observes. “We think it’ll come down to software in the inverter. The inverter essentially controls the drivetrain and the dynamic response, and when you start playing with the software with the driver experience in mind, you can start to do some really interesting things. “That’s really why the latest buzz-term is ‘software-defined vehicle’. You can start defining how an EV’s drivetrain works through the software in either its inverter or vehicle control unit. Even two vehicles with the same drivetrain could respond in totally different ways based on how they’ve been programmed.” The IPG5 These factors have informed McLaren Applied’s development of the IPG5, as have lessons it has learned from motorsport. However, Lambert and his team knew from the outset that it would need to be developed from the ground up, rather than being derived from a motorsport design, given the need for cost optimisation, functional safety and scalability of production. “For instance, in motorsport we might use an FPGA for controlling the inverter, which gets us very fast and reliable processing, but they are expensive, and there are functional safety concerns about them,” Lambert says. “So a lot of r&d went into finding similarly powerful processors that were rated for automotive safety. That might have meant sacrificing some programming freedom, but if In conversation | Stephen Lambert 18 May/June 2023 | E-Mobility Engineering Stephen Lambert Stephen Lambert was born in Abergavenny, in South Wales, UK, and completed his secondary education at Hereford Cathedral School. He went on to study at the University of Warwick from 2002 to 2006 for his MEng degree in Computer Systems Engineering, where he took part in Formula Student and became the electrical and electronics team leader for his racing group. While there, he designed an electronic clutchless gear-change control system, which won an award for innovative use of electronics in a Formula Student racecar. From 2006 he worked for his engineering doctorate as a research engineer (also at Warwick) while working as a project engineer at Potenza Technology, before going on to work at Lotus as principal engineer for hybrid and EV integration. He left Lotus in 2012 to work as engineering manager at battery company Goodwolfe Energy, and then in 2013 became the battery systems engineer for McLaren Racing’s Formula One team. Working as the managing director of battery maker Vayon Energy Storage, from late 2015 to late 2016, he moved to McLaren Applied in November 2016 to become head of electrification, a position he still holds. Since 2019 he has also served as chairman of the Automotive Electronics Systems Innovation Network, a not-for-profit aimed at facilitating networking and collaboration to take on challenges facing the automotive electronics industry, such as identifying sectors where higher levels of funding or skilled graduates are needed for companies to thrive.