Power Split Architecture

[nsteblay]

Found this site that shows how the hybrid power split architecture works.

 

http://eahart.com/prius/psd/

 

The model is based on the current Prius.  The C-Max uses a similar architecture but has changed the size and power of the ICE and electric motor/generators (MG1 and MG2).  

 

In the simulation it is interesting to see how the planetary gear system acts as the CVT and how the MGs combine to keep ICE rpms at a minimum for a given speed.  

 

Disclaimer - the remainder of this email is personal conjecture based on my limited knowledge of mechanics.  I have driven both the Prius and C-Max.

 

My sense is Ford with the increased size of the ICE and MG1 has loosened the rules within the hybrid computer software that allows for more manual control and hence more variability.  Ford sacrificed some fuel efficiency through styling (less aerodynamic) and overall weight of the car.  Toyota has taken a "systems" approach to their overall architecture - balancing all pertinent components and hybrid controls to achieve the highest MPG but sacrificing on the driving experience (my opinion).  

 

For those that want high mpg with less dependency on driving style the Prius is probably the right choice.  For those that want the better driving experience (my opinion) and greater power with the sacrifice of greater mpg variability and dependency on driving style the C-Max is a better choice.  

Edited August 31, 2013 by nsteblay

[RaPieR]

Found this site that shows how the hybrid power split architecture works.

 

http://eahart.com/prius/psd/

 

The model is based on the current Prius.  The C-Max uses a similar architecture but has changed the size and power of the ICE and electric motor/generators (MG1 and MG2).  

 

In the simulation it is interesting to see how the planetary gear system acts as the CVT and how the MGs combine to keep ICE rpms at a minimum for a given speed.  

 

Disclaimer - the remainder of this email is personal conjecture based on my limited knowledge of mechanics.  I have driven both the Prius and C-Max.

 

My sense is Ford with the increased size of the ICE and MG1 has loosened the rules within the hybrid computer software that allows for more manual control and hence more variability.  Ford sacrificed some fuel efficiency through styling (less aerodynamic) and overall weight of the car.  Toyota has taken a "systems" approach to their overall architecture - balancing all pertinent components and hybrid controls to achieve the highest MPG but sacrificing on the driving experience (my opinion).  

 

For those that want high mpg with less dependency on driving style the Prius is probably the right choice.  For those that want the better driving experience (my opinion) and greater power with the sacrifice of greater mpg variability and dependency on driving style the C-Max is a better choice.  

That's a pretty cool simulation.  Thanks for the info.  Another thing to note with Ford on the C-Max, Fusion, and all their hybrids is that they are all shared platforms.  Unlike Toyota, they haven't pursued a pure hybrid platform but instead chose to use existing platforms and just modified them to accept the hybrid powertrain.

[HannahWCU]

I've posted a link somewhere on the forum to a long boring (but informative) Youtube video that shows how the Prius drivetrain works. The guy has the inner guts from the eCVT that he uses to demonstrate.