Orion buses
There are buses (Orion) that use this setup, but they need a battery just like a normal hybrid (e.g. Prius) needs a battery to handle regenerative braking to recover braking energy and to handle acceleration. I think this setup works well for buses because you don't need a massive transmission and you also get the great torque of electric motors. I believe that is why this setup is used on trains too.
In my opinion, the reason one would not use this setup for a car is that you would need a very large electric motor to move the car, as well as a large generator. In a normal HEV design (Prius) you can use smaller electric motors and a smaller ICE. You do not need the massive torque and thus the transmission requirements are not as heavy duty.
When I asked a GM Volt engineer at Volt Nation what they think the advantage of the E-REV design is, she said it was to maximize use of grid power.
My current thoughts on this are that if you are going to have a plug-in with a long range on battery power, the E-REV design is best. If ther is no plug-in ability or a very small range on battery power the Prius-type setup makes the most sense. GM is doing both with the E-Flex and the 2-mode designs.
There are buses (Orion) that use this setup, but they need a battery just like a normal hybrid (e.g. Prius) needs a battery to handle regenerative braking to recover braking energy and to handle acceleration. I think this setup works well for buses because you don't need a massive transmission and you also get the great torque of electric motors. I believe that is why this setup is used on trains too.
In my opinion, the reason one would not use this setup for a car is that you would need a very large electric motor to move the car, as well as a large generator. In a normal HEV design (Prius) you can use smaller electric motors and a smaller ICE. You do not need the massive torque and thus the transmission requirements are not as heavy duty.
When I asked a GM Volt engineer at Volt Nation what they think the advantage of the E-REV design is, she said it was to maximize use of grid power.
My current thoughts on this are that if you are going to have a plug-in with a long range on battery power, the E-REV design is best. If ther is no plug-in ability or a very small range on battery power the Prius-type setup makes the most sense. GM is doing both with the E-Flex and the 2-mode designs.
