More Data about the Generator:

Desired Torque / raw # / Measured Torque / raw # / notes

FFFE / -1 / 0000 / 0 / In Park with ICE on deadband
FF69 / -152 / FF62 / -159 / Charging battery with ICE on in Park
0020 / 32 / 001E / 30 / Braking from 20 MPH with ICE on in Drive
0081 / 129 / 0081 / 129 / During Engine Brake / Engine Run Up in Low
FFFE / -1 / FFFE / -1 / Braking from 20 MPH with ICE on in Neutral
0000 / 0 / 0000 / 0 / Coast ( glide ) at 20 MPH in Neutral ICE on
0000 / 0 / 0000 / 0 / Coast ( glide ) at 20 MPH in Neutral EV
0000 / 0 / 0000 / 0 / Braking at 20 MPH in Drive EV

While coasting at 20 MPH in neutral the Generator RPM is -3120
While coasting at 20 MPH in neutral the Generator Torque desired is 0
While coasting at 20 MPH in neutral the Generator Torque produced is 0
While coasting at 20 MPH in neutral the HV battery is putting out 1.6A

The baseline (load) for electronics in the car is +/- 500 watts.
( computers, fans, water pumps, dashboard, etc, )
The above is steady, and repeatable over and over with the same result.

So can somebody tell me how the generator can spin at -3120 RPM and produce zero torque, nor consume any torque, nor take any amperage out of the HV battery, and be "disconnected" at the same time???

Gary?

 

It is possible for the electronics to apply a "neutral" current to the MG1 to allow a 0 torque. this would be similar to the creep mode in D/L that does not show but is never the less there. This would also act as a flywheel that is attached to the drive wheels allowing a further coast. I do not think there is a mechanical disconect, but a electronic disconect. There would be no real reason to mechanicaly disconect. Planitary gears by design "disconect" when none of the components are loaded. This is how neutral is achieved in most conventional automatic transmissions.

 

All of this is a lot to read, but it appears there is an idea that a spinning motor/gen must be acting as a motor or a generator. Unless this is a permanent magnet motor/gen, it takes field current to do anything! And field current can be disconnected.

 

This is what I believe to be true, and there is strong evidence to support this.

If you neither apply a current, nor apply a load, you can "spin" a motor in a "neutral" state. The spin comes from the momentum of the turning wheels.

 

GaryG — Which US patent (or other source) are you quoting from in post #55? You don't seem to say. By the way, in the Ford FEH/MMH "2005 MY OBD System Operation Summary for Hybrid Electric Vehicles" manual that you referred to on cleanmpg.com (I tried attaching it hereto, but the GH site refuses to accept it for some reason — GaryG can you please repost it here to help me out?), I note that the powertrain control system diagram on page 9 essentially repeats Fig. 1 from both US patents #6 793 034 and 6 405 818 (I'm attaching the latter hereto), and explicitly shows that the FEH/MMH system contains:
(a) a "one-way clutch" between the ICE and the planetary gear,
(b) a "generator brake" between the generator and the planetary gear, and
(c) a statement on the block diagram that the PCM can issue a "generator brake command."
[Other interesting information is also given on pages, 5-8, and 64.]

Now, the one-way ICE clutch would presumably be a passively-operating mechanical clutch, and inaudible. It would allow the transaxle planetary carrier shaft speed to exceed that of the ICE without spinning up the ICE. Is that what's happening during downhill coasting or power-off towing? I must mention that, in patent #6 405 818 referred to above (see col. 3, lines 7-14; col. 7, lines 60-67; col. 8, lines 17-26) it is stated that, in this arrangement, the generator clutch can be engaged when starting the ICE, and also at other times. This adds credence to some of your statements in earlier posts. [This patent also discusses, inter alia, engine braking = fuel-cut spinning of the ICE (col. 5, lines 36-51), quasi-"heretical"-mode operation (col. 6, lines 57-67), battery charging in 'N' (col. 7, line 18), and using MG1 as a motor to slow and stop the ICE (col. 7, lines 29-36).]

gpsman1 — In post #61 your decoding of negative hexadecimal numbers into decimal is wrong by one. For example:
FFFF = -1
FFFE = -2
etc. To handle negative 2s-complement numbers correctly, one negates all the binary digits, and then adds one before negating again. So:
FFFF => 0000 = 0 => 1 => -1
FFFE = FFF(1110) => 000(0001) = 1 => 2 => -2
etc.

As long as there's no current flowing through a MG, it generates/consumes no power, and so is doing no work (either positive or negative). The controller electronics determines whether a MG acts as a generator or a motor by controlling the load placed on it — essentially by controlling the inverter voltage. So, with no load, the MG just spins freely. The only possible danger is that it still produces a voltage across its coils while spinning freely, and this could create the danger of electrical breakdown in the motor insulation or inverter transistors if the MG spins too fast. Since MG2 is tied to the wheel speed, there's no real danger unless bad wheel spin occurs. MG1 can spin very fast, however, when the ICE isn't turning. Hence the need for fuel-cut spinning of the ICE (what you call "run-up") to protect MG1 from mechanical and electrical damage from over-revving.

DavidH — The MGs are permanent magnet motors. There are no field coils to disconnect.

Stan

 

Thanks Stan.
I thought I may be "off by one" but 1 RPM out of 6000 ( or 1 Nm ) does not change the operation characteristics. ( much )


So another question is:
If the car CAN disconnect ( physically ) the motors while in motion, how come all the over the road evidence shows it doesn't?

 

I did some research. The motor and geneartator are PM (Permanent Magnet) devices. And, both will produce current when spinning if a load is connected. When a load is not connected, the stator winding produces a high voltage as SPL describes.

I did find a FORD diagram that shows a one way clutch on the ICE.

 

I do not think the placement or operation of the OWC is being debated. Is it?

The purpose of the OWC is to prevent torque being applied to the ICE in the reverse direction, since the generator can spin either direction at any time, based on conditions.

 

Please tell where, I am still not quite sure of its function. I thought it might have something to do with ICE off operation.

 

gpsman1 — I think I need to modify what I said about the one-way clutch in my post #65. I spoke of it as if it were in-line between the ICE and the planetary-gear set. Closer inspection of the diagrams, however, shows that it is actually between the ICE output shaft and chassis. Thus, it serves solely to prevent the ICE from being spun backwards — say, if the vehicle were being towed backwards, with its front wheels on the ground. Then it wouldn't decouple the ICE's drive shaft from the planetary-gear set if the latter were turning faster than the ICE, as I had suggested earlier.

Stan