Honda Power Unit Hardware & Software

[gruntguru]

I will wait for the translation where Honda says they are doing this.

I believe they have added the ability to transfer direct from K to H but only use it in situations where the energy can be used immediately - not using the H as a way-station to transfer between the K and the ES.

IMO the FIA wouldn't even need to change the rules to stop this. Its a clear case of "not in the spirit of the rules". As I said before - why not remove the 2 and 4 MJ limits if there is a way around them?

[OO7]

The 40 pulses of K spinning up the H would be interleaved with 40 pulses of K direct to ES, so the net result at the K is a constant 120kW of retardation, not pulsed at all.

Hi Craigy

I don't understand why the K would be used to spin up the H?

[bill shoe]

So long as the ES SoC doesn't go below a nominal 0 or above a maximum 4MJ,
The ES can transfer any amount of energy you like to the H, at any rate.
The H can transfer any amount of energy you like to the K, at any rate (though the K can only "consume" energy at 120kW).

The suggestion is that this ES to H transfer, then H to K transfer is interleaved, and the switch is done many times per second, and that it's also a reversible process (that is to say the K can charge up the ES using the H as a go-between).

The "unusual energy flow" is legal according to my reading of the rules. What rule would it breach, according to your reading of the rules?

My mind glazed over as I read much of the recent discussion about energy flow. But with this post I get it!

The H has non-zero rotational inertia, so it has mechanical energy storage capability whether we like it or not. Energy rate in or out the H is unlimited. But energy can only be put into the K at 120kW. So anytime you are "on the gas" the K will always be fed 120 kW of electrical power. The source of this power just switches back and forth rapidly between the 4MJ ES supply and the H rotational-inertia supply. In this manner the ES 4MJ is prolonged over the entire lap even though the K is always getting 120kW of power. In the milliseconds when the K is fed by the ES instead of the H, the H is also getting fed by the ES. Brilliant.

Just putting it in my own words to help myself understand it better. Craigy has good candidate for best post of the year.

[Craigy]

The 40 pulses of K spinning up the H would be interleaved with 40 pulses of K direct to ES, so the net result at the K is a constant 120kW of retardation, not pulsed at all.

Hi Craigy

I don't understand why the K would be used to spin up the H?

There's an energy limit of 2MJ on the direct connection from K->ES per lap per FIA F1 technical regulations.
From ES->K, the equivalent limit is 4MJ, so it's not a symmetrical limitation in the regulations.
If you want to deploy 4MJ (or more) of energy per lap out of the K, then you need a way to harvest it.

There's no regulated limit on the energy per lap the K can send to the H, and no regulated limit per lap on the energy the H can send to the ES.

Consequently, you can elect to send >2MJ from the K to the ES, so long as the H is used as a go-between for any amount over 2MJ per lap.

Since the H can't both speed up (receiving energy from the K) and spin down (sending energy to the ES) at the same time, you would switch between sending energy K->H then stopping that, and starting to discharge energy H->ES, and back to K->H again, and so on, many times per second.

The switching would speed up and slow down the H only a small amount each time it is spun up by the energy from the K or spun down by sending energy to the ES, keeping it (and all the rest of the turbo/compressor) in -or very close to- the range the ICE needs.

Because the H is spending some of its time sending energy to the ES, the K can be used during that time to send energy directly to the ES, inside the 2MJ "direct" route regulated amount. Thus the K can actually be harvesting all the time, even when the H is busy dumping energy into the ES.

The K is switching from sending energy direct to the ES, then to the H, then to the ES, then to the H, about 40 times per second in the Honda docs.
All this energy ultimately gets into the ES, but the 2MJ limit only applies to direct K->ES transfers.

It's a way to get 4MJ or more into the ES per lap, without relying on the MGU-H's other job, which is compounding energy out of exhaust gases.

[wuzak]

So long as the ES SoC doesn't go below a nominal 0 or above a maximum 4MJ,
The ES can transfer any amount of energy you like to the H, at any rate.
The H can transfer any amount of energy you like to the K, at any rate (though the K can only "consume" energy at 120kW).

The suggestion is that this ES to H transfer, then H to K transfer is interleaved, and the switch is done many times per second, and that it's also a reversible process (that is to say the K can charge up the ES using the H as a go-between).

The "unusual energy flow" is legal according to my reading of the rules. What rule would it breach, according to your reading of the rules?

My mind glazed over as I read much of the recent discussion about energy flow. But with this post I get it!

The H has non-zero rotational inertia, so it has mechanical energy storage capability whether we like it or not. Energy rate in or out the H is unlimited. But energy can only be put into the K at 120kW. So anytime you are "on the gas" the K will always be fed 120 kW of electrical power. The source of this power just switches back and forth rapidly between the 4MJ ES supply and the H rotational-inertia supply. In this manner the ES 4MJ is prolonged over the entire lap even though the K is always getting 120kW of power. In the milliseconds when the K is fed by the ES instead of the H, the H is also getting fed by the ES. Brilliant.

Just putting it in my own words to help myself understand it better. Craigy has good candidate for best post of the year.

They are actually talking about using the unlimited energy transfer between the MGUK and MGUH to cheat the 2MJ MGUK to ES storage limit.

The basis for this is an energy flow diagram which depicts 1MJ being sent from the MGUK to the MGUH and then 1MJ from the MGUH to the MGUK, and a set of squiggly lines on a performance plot.

And if you think about it, the theoretical energy flow is, in reality:

MGUK -> CE -> MGUH -> CE -> ES

Switching between that and
turbo/angular momentum -> MGUH -> CE -> ES?

Switching between the ES and MGUH to drive the MGUK would seem to be pointless, as you would be switching between having 160hp and 80hp. Better to use the MGUH to send all its power to the MGUK as a continuous stream and supplement that with power from the ES. That way you are drawing a lower power level from the ES to give to the MGUK and still have 160hp output.

[Craigy]

My mind glazed over as I read much of the recent discussion about energy flow. But with this post I get it!

I'd like Giorgio Piola & Scarbs to do a slick animation of this.

In this case, it would definitely be worth more than a thousand words.

[Craigy]

...The basis for this is an energy flow diagram which depicts 1MJ being sent from the MGUK to the MGUH and then 1MJ from the MGUH to the MGUK, and a set of squiggly lines on a performance plot.

I'm afraid you're wrong there. The basis for this is an idea I had about 2 years ago. Happily, I posted on F1technical about it at the time so I can prove it.
The timestamp for that post is Tue Feb 09, 2016 2:36 pm. It's in the Mercedes PU thread if you want to read it.
viewtopic.php?f=4&t=23688&p=617506

My idea at the time wasn't fully-formed as I was missing the "switch it on and off fast to keep the compressor in the correct working range" part of the solution.

I didn't keep talking it through at the time, because of the reaction from gruntguru and others.

It was nice to see the Honda article though.

[Craigy]

Switching between the ES and MGUH to drive the MGUK would seem to be pointless, as you would be switching between having 160hp and 80hp. Better to use the MGUH to send all its power to the MGUK as a continuous stream and supplement that with power from the ES. That way you are drawing a lower power level from the ES to give to the MGUK and still have 160hp output.

I'm not sure where you're getting 80hp (60kW) from. The H isn't limited to 60kW. It is not limited at all.

[wuzak]

Switching between the ES and MGUH to drive the MGUK would seem to be pointless, as you would be switching between having 160hp and 80hp. Better to use the MGUH to send all its power to the MGUK as a continuous stream and supplement that with power from the ES. That way you are drawing a lower power level from the ES to give to the MGUK and still have 160hp output.

I'm not sure where you're getting 80hp (60kW) from. The H isn't limited to 60kW. It is not limited at all.

An estimate.

It sure as hell isn't recovering 160hp from the exhaust. And if it was, you wouldn't need to muck around with the stuff you are proposing.

[Jolle]

I assume all the PU builders have multiple teams working on stuff whenever the rules state “unlimited” or “free” at some point to take full advantage (like the energy flow between the H and K units). I suspect from all PU’s some clever transfers.

[Craigy]

Switching between the ES and MGUH to drive the MGUK would seem to be pointless, as you would be switching between having 160hp and 80hp. Better to use the MGUH to send all its power to the MGUK as a continuous stream and supplement that with power from the ES. That way you are drawing a lower power level from the ES to give to the MGUK and still have 160hp output.

I'm not sure where you're getting 80hp (60kW) from. The H isn't limited to 60kW. It is not limited at all.

An estimate.

It sure as hell isn't recovering 160hp from the exhaust. And if it was, you wouldn't need to muck around with the stuff you are proposing.

Why suggest 60kW when there's more performance available by giving it a larger capacity?
Is your estimate based purely on using the H as a recovery device for the exhaust, ignoring the opportunities of the flywheel system?

If the exhaust recovery is the smaller of the two jobs here (and it is, unless someone has built an engine with 120kW of recoverable exhaust energy), then there's no reason to size the H as small as only 60kW.

If you want the H to power the K, it should be able to deploy at 120kW in that direction (H->K) as that's what the K is permitted to consume in the regulations.

On the flipside, if you want the H to be able to charge up the ES, it should be able to send power there at whatever rate you're getting from the exhaust recovery (say, peak 60kW as you suggest, just for discussion), PLUS whatever rate you want to discharge energy from H flywheel inertia to ES at.
Since you want to spend a small amount of time with the H not being charged by the K, you would make that rate quite high - it wouldn't need to be limited to 60kW, or even 120kW. It could easily be 240kW or more from H to ES.

Either way, the H should be able to receive power from the K at a minimum of at least 120kW since that's what the K is capable of.

[Tommy Cookers]

in Craigy's 2016 post re this 'energy transfer' route he was advocating recovering energy under braking ie waste energy
apparently the reason others were unconvinced

now we are looking at electrically accumulating and using much more energy, taken from the burning of fuel
we have a few days ago seen that Honda are K generating before any braking
what else does the Honda data show regarding the source of this extra transferred energy ?
energy transfer will be poor unless MGU-H rpm is quite close to maximum (high load low rpm means excessive current)

a much bigger (current) MGU-H would possibly not reach 125000 rpm as current switching in the bigger drives will be slower
one ingenuity of the rules seems to be the size match of K to H giving some efficient use of system parts

[wuzak]

I'm not sure where you're getting 80hp (60kW) from. The H isn't limited to 60kW. It is not limited at all.

An estimate.

It sure as hell isn't recovering 160hp from the exhaust. And if it was, you wouldn't need to muck around with the stuff you are proposing.

Why suggest 60kW when there's more performance available by giving it a larger capacity?
Is your estimate based purely on using the H as a recovery device for the exhaust, ignoring the opportunities of the flywheel system?

If the exhaust recovery is the smaller of the two jobs here (and it is, unless someone has built an engine with 120kW of recoverable exhaust energy), then there's no reason to size the H as small as only 60kW.

If you want the H to power the K, it should be able to deploy at 120kW in that direction (H->K) as that's what the K is permitted to consume in the regulations.

On the flipside, if you want the H to be able to charge up the ES, it should be able to send power there at whatever rate you're getting from the exhaust recovery (say, peak 60kW as you suggest, just for discussion), PLUS whatever rate you want to discharge energy from H flywheel inertia to ES at.
Since you want to spend a small amount of time with the H not being charged by the K, you would make that rate quite high - it wouldn't need to be limited to 60kW, or even 120kW. It could easily be 240kW or more from H to ES.

Either way, the H should be able to receive power from the K at a minimum of at least 120kW since that's what the K is capable of.

The H could only ever receive 120kW (plus a small efficiency factor) from the K, as the K is limited to 120kW in either motor or generator mode.

Quite why you would want the H to be able to generate 240kW is beyond me, unless that is the power required for spooling the turbo. Which I doubt.

But the spooling power requirement is likely to be the sizing factor for the H, not the recovery power.

[wuzak]

now we are looking at electrically accumulating and using much more energy, taken from the burning of fuel
we have a few days ago seen that Honda are K generating before any braking

Before braking may be simply lift and coast, rather than burning fuel.

You would expect that the burning fuel side of that would occur with the car accelerating in low traction zones. At that point the tyres will not take the power from the engine and the MGUK, so they could give the potential power from the engine and cut the output power back to what the tyres can take by using the K.

In this situation the K could be used to spool the turbo to cut lag, if the engine is at low revs. And in this sense the K could be recovering more energy than is allowed, the effective storage being that the H does not have to retrieve that energy from the ES.

[wuzak]

Looking at the numbers suggested by the chart - 1MJ (extra) recovered via the H.

That means that the K will be driving the H at 120kW for 8.33s.

If the H is size matched for the K, it will be feeding the ES for a further 8.33s.

So, the H will be occupied for 16.7s of a lap doing this workaround recovery.