17 John Stamford | In conversation E-Mobility Engineering | January/February 2025 Racing innovation In 2007, when Formula One began discussing plans for hybrid technology, Mercedes AMG High Performance Powertrains hired Ricardo on a consultancy basis to help build its knowledge base. Soon after, it took on Stamford as head of electronics. In 2009, the optional use of the Kinetic Energy Recovery System (KERS) was introduced, with four teams – including McLaren Mercedes – putting it to use, but only at certain circuits where it offered enough benefit. Having experimented with Flybrid’s flywheel approach and other tech, Mercedes opted for a more traditional system with a maximum permitted power of 60 kW. Its system was the first to win, in Hungary, but the marginal laptime benefits did not justify the investment for many and the system was dropped for a season, before returning in 2011. Mercedes focused on reducing size and weight, and it used improved transistors and in-house power modules, working closely with battery suppliers to boost the power density of the cells by optimising the chemical, electrical and mechanical aspects of the cell. At the same time, the company wanted to quickly apply EV technology in a roadcar project and this led to the creation of the SLS AMG Electric Drive, for which Stamford was made chief engineer of the battery technology. The car was designed with four 150 kW electric motors, one in each corner, and a 60 kWh battery using innovative pouch-cell technology. The system was packaged in the engine compartment and the transmission tunnel, and the car beat its ICE equivalent in a straight line, although it lost out on a lap of the legendary Nürburgring circuit due to its weight. “Mainstream developments were taking five or six years, but the race team was able to do it much more quickly,” he recalls. “It was a really exciting project because we were pushing cell and battery technology hard, as well as developing advanced battery management features. It was a combined energy and power requirement, because it needed to have both the power and range, which we were aiming to get north of 250 km.” Even at that point, the EV landscape was still fairly intermittent. Interest in early prototypes had waned, but companies were starting to believe EVs were on the cusp again and many were starting to conduct market testing. A number of different offerings started to appear on the market, but they were not seeing much take-up. When Formula One doubled down on energy recovery systems – literally duty vehicles, and shifting focus from specifying ECUs to designing and manufacturing them. He spent the next four years innovating in the ECU design space, mainly on control systems in high-temperature and high-vibration operating environments, but when the company chose to relocate to Germany, he stayed in the UK and joined an old boss at Ricardo. It was there that Stamford set about establishing the Ricardo electronics group, most notably developing the Bugatti Veyron dual-clutch transmission-control unit. Following the project’s successful conclusion, he returned to the EV space, developing hybrid innovations for various OEMs. In the short time since leaving Wavedriver, technology had moved on and minor fuel-efficiency gains were to be had, firstly with what Stamford calls “micro hybrids”, which use the alternator as a battery starter generator, and then with more powerful “mild and full hybrids”, which provided limited amounts of electric-only operation. This work attracted the attention of Chinese OEMs, including Cherry, but Stamford recalls: “The electronics and drive systems were there, but people hadn’t really integrated them. The batteries were improving, and were adapted to be less about cold cranking amps and more about accepting and delivering energy, but in those early days it was all about the application and learning about the technology. “There were no real voltage standards for the mild, hybrid systems – some were 48 V, some hundreds of volts – while the drive components, consisting of IGBTs [insulated-gate bipolar transistors], capacitors and transient suppressors, as well as battery management systems, and the control software and systems that go around those devices, needed progressing in terms of integration and diagnostics. There was a huge amount of learning about what was important at a system level.” John Stamford It was a really exciting project… we were pushing cell and battery technology hard, and developing advanced battery management features
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