MG1 Only in High-Power Situations

The Prime can use MG1 in addition to MG2 & ICE to power the wheels in high power situations. In low power situations it functions like any other Prius or plug-in Prius.

All other Prius generations & models only use MG2 & ICE in high power situations. In other situations, MG2 powers the wheels & performs regenerative breaking when necessary. MG1 primarily starts the ICE and charges the traction battery from the ICE.

 

Charge mode also?

Posted via the PriusChat mobile app.

 

I am not that well versed in the plugins. @bisco or @bwilson4web might know. They should be along shortly.

 

I just bought a month of Toyota TIS service because I want four specific procedures done:

• RM1...ZOBY - Hybrid Transaxle Fluid Adjustment
• RM1...10216 - Maintenance: Oil and Oil filter replacement
• RM1...Z1LV - Front Wheel Alignment
• RM1...Z1LW - Rear Wheel Alignment

I'll find the exact TIS document later (while waiting on service.) This is my understanding:

1. MG2 - is reverse motor.
2. MG2 - in low power, engine off modes, provides forward motion power.
   
3. MG1 - is counter torque required when engine is running.
   
4. MG1 - The Prime has the ability to keep the engine off and add MG1 to MG2 to provide forward motion.

I'll have more technical details including the one-way clutch that allows MG1 and MG2 to couple together.

Bob Wilson

 

Thanks, Bob

 

The acceleration measurements so far provided seem to indicate that dual-motor mode doesn't work as the actual power to the wheels never exceeds the rating of MG2.

 

How measured?

Bob Wilson

 

0-60 times, including video on this one:

Bragging Rights !!!!!!! | Page 20 | PriusChat

 

Thanks!

That posting predates my interest in the Prime so I hadn't seen it. I'll see if I can get some dry pavement, standard day metrics.

Bob Wilson

 

That would be helpful, but the car wasn't having traction problems when the power limitation occurred.

 

but the car wasn't having traction problems when the power limitation occurred.



To make sure I understand, at 40 mph, you're seeing about 59000 W. Based upon mass and acceleration, right?

Regardless, another set of metrics won't hurt.

Bob Wilson

 

It's not really that MG1 is not used but that it doesn't take much power in many situations. It is used all the time.

During low road speed but high road wheel torque situations MG1 is used as a generator supplying up to 30kW or so to MG2 to give the eCVT action. Under cruising conditions it may do the reverse and act as a motor taking power from MG2 to keep the ICE RPM down.

Starting the engine when transitioning from EV mode to hybrid mode may be nothing more than MG1 slowing down to let the vehicle momentum start the ICE.

MG1 has to spin at the appropriate speed to keep the engine at the required RPM. For example in low speed EV mode it has to keep the ICE stationery, at high road speeds it has to keep the ICE at ~960RPM.

kevin

 

55,000W (the polynomial makes it look a little larger) and the latest version of this chart (which has better estimates for aero drag, and which I don't have handy) has it at about 53,000W. According to Toyota's written specs for dual-motor mode, it should be 68kW, and according to the specs for the individual motors and the words of the chief engineer, it should be 76kW.

 

@Lee Jay , I wonder if a slight slope up of the track (say 1%) will make a dent in the calculations?

 

First, I carefully verified where he was and determined thr slope was very nearly zero in both cases. Second, it would take more than 1% to make this change. Third, others have come up with similar times to this test.