HSG: THE SMART CHOICEThe idea, quickly validated by Ahmed Ketfi-Cherif, was to add a second electric motor to the E-TECH hybrid system under construction: "Its role is to replace the synchronizers of a traditional gearbox to facilitate the clutch and therefore the gear change. By working in conjunction with the electric traction motor, it allows very precise regulation of the speed of rotation of the gearbox for smooth gear changes."
Ahmed and Nicolas Fremau updated the LEGO model with this solution and started bench and road tests
. This allowed them to observe that this second electric motor, named HSG for High-voltage Starter Generator, brings other benefits to the system. Its immediate torque contribution
smoothes acceleration at low speeds to avoid any sensation of torque breakage at the time of gear changes. At low speeds, it allows the system to operate as a 'series hybrid'
for greater comfort and flexibility. Without the need for a lot of stored energy, which allowed the battery capacity to be reduced and the charging socket to be removed.
The future E-TECH engine, originally a plug-in hybrid, had just been split into a 'simple' hybrid version. The possibilities for use in the range were multiplied!