3 — Mercedes bumps up cooling efficiency
Mercedes has increased the size of its ERS cooler, which has led its engineers to widen the W06 Hybrid’s bodywork in the area. This why one could spot two bulges around the water radiator placed atop the gearbox. This evolution did not randomly appear at Montreal, where Mercedes had suffered a double control electronics failure 12 months ago. These issues had led to the MGU-K not functioning anymore on both Silver Arrows. Due to their repeated heavy braking periods, the Canadian and Austrian Grand Prix venues are among the most critical tracks in terms of ERS cooling requirements, with a lot of kinetic energy being recovered over one lap.
The energy store, or battery, works on direct current, while both MGUs are operating on three-phase alternating current. Consequently, there must be an electrical conversion between the two systems, and this is where the ERS control electronics (CE) come into play. There are actually two CE units – one for the MGU-K, another for the MGU-H – and both work the same way. Converting AC power into DC voltage (and vice-versa) leads to heat being released in the CE systems.
When one of the motor generator unit recovers energy, it sends AC power to the appropriate control electronics system via three high-current cables. Inside the CE unit, several high-current devices then convert AC voltage to DC power. The control electronics then send the direct current to the energy store through another pair of cables. Reciprocally, when the battery sends DC voltage to the CE – in order to give some extra power to the ICE – the current just follows the same process, albeit on the opposite route.
Better ERS cooling enables the Mercedes engineers to improve their car’s overall reliability in a vital area – but also boosts its performance since bigger electrical transfers no longer lead to overheating troubles.
