Sometimes the bus will run more on electric and other times it would blend more of the diesel in. The hybrid has a CVT transmission which automatically adapts the gear ratio to the terrain and engine load as well as the performance setting of the hybrid propulsion system. I then took the curve for the Remy 250 and used that to compute the torque (m). The calculation of the traction motor RPM (n) uses the driveshaft rpm and gear ratio as a function in order to compute the traction motor rpm (n). I tried my best to simulate the bus based off of that information. The script hybrid uses torque data a Remy 250 motor, not entirely too sure if Allison used that vendor for the EP40 but they have dealt with Remy in the past.Īllison has released an 'theory of operation' ( …eory%20of%20Operation.pdf ). Once in the second mode, motor B will kick in. The first mode is when Motor A does much of the acceleration from 0-10 mph, as the traction motors reaches speeds above 10 mph/depending on the battery charge the motor will fade out completely, therefore the diesel would kick in until the bus reaches the second mode/gear. Just a little break down as to how the script works: It is based off of the Allison EP40 transmission with two modes. Scripted a hybrid transmission well actually this has been a Work in progress for an while now.