yes that's right (and I was wrong)henry wrote: ↑16 Oct 2019, 18:56The tractive effort at the road is power/road speed. If the power stays constant and the road speed decreases the tractive effort goes up. The gear changes keep the K, and ICE, in their operating range. As you have said in other places they keep the revs high to keep the K torque and current down.Tommy Cookers wrote: ↑16 Oct 2019, 18:32as the road speed decreases doesn't the braking force (rear axle torque) from the K remain afap constant ?
as downshifting gives afap constant '120 kW' power by maintaining afap ideal K rpm (voltage) and ideal K torque (current)
without downshifting the K torque would need to increase with falling roadspeed and the K and C would go off-design
or if the K torque (current) was made constant the K power would fall below '120 kW'
downshifting is the (major) mechanism increasing the regen braking axle torque as road speed reduces
so the mechanical side is apparently helping out the electrical side by keeping K torque rather constant
(but step-by-step downshifting is anyway compulsory)