F1technical.net

the '120 kW' power limit of the MGU-K is defined as DC power draw
and there is no demand for mechanical measurement in this regard

but the rules do not demand a wholly DC system
they leave what could be seen as an open door to energise its electric motor action at higher power via a non-DC, non-storage route

and there's no actually overwhelming reason to render all propulsion electrical energy streams DC at some point
eg if the future of humankind depended on it being a no-DC system, it could be so done

granted this aspect seems irrelevant given that exhaust recovery is unlikely to trouble the above limit

livinglikethathuh wrote:^ With the MGU-K and H both operating AC, why is there a need to convert to DC? From ES to -H or -K I can understand but not this.
Am I missing something?

In the article they say the battery pack operate DC.

Tommy Cookers wrote:the '120 kW' power limit of the MGU-K is defined as DC power draw
and there is no demand for mechanical measurement in this regard

More precisely a DC measurement. The effective voltage and the current over a shunt...no loss.
The question is, how this is done in reality. I assume they have the necessary voltmeters on the power outlet of the control unit.

Tommy Cookers wrote: but the rules do not demand a wholly DC system
they leave what could be seen as an open door to energise its electric motor action at higher power via a non-DC, non-storage route

and there's no actually overwhelming reason to render all propulsion electrical energy streams DC at some point
eg if the future of humankind depended on it being a no-DC system, it could be so done

No, the frequency is always different. There is no way to drive the K with the H without an inverter.

basti313 wrote:

Tommy Cookers wrote:the '120 kW' power limit of the MGU-K is defined as DC power draw
and there is no demand for mechanical measurement in this regard

More precisely a DC measurement. The effective voltage and the current over a shunt...no loss.
The question is, how this is done in reality. I assume they have the necessary voltmeters on the power outlet of the control unit.

Tommy Cookers wrote: but the rules do not demand a wholly DC system
they leave what could be seen as an open door to energise its electric motor action at higher power via a non-DC, non-storage route

and there's no actually overwhelming reason to render all propulsion electrical energy streams DC at some point
eg if the future of humankind depended on it being a no-DC system, it could be so done

No, the frequency is always different. There is no way to drive the K with the H without an inverter.

Granted it sounds like a heinous problem to solve (with the juice possibly not worth the squeeze), but since there can be a fixed ratio applied to gear the -H and -K, could you not design for a state where they were both turning very close to the same speed as the car approaches terminal velocity? At that point, the control system for the -H could lock it's speed to the -K and the 3-phase AC could be routed directly between them. The boost would vary slightly as velocity changes, (or the -H's clutch could be modulated slightly?). In other states, a DC route could be used to charge the ES. That same DC route could also load the -H appropriately to charge the ES with any energy the -K cannot utilize.

SO.... probably not

Surely you could drive the MGUK directly from the MGUH, but its output would not be controlled?

The power would be whatever the MGUH delivered, the speed would be dependent on the MGUH and not have a relationship to what the driver actually demands.

wuzak wrote:Surely you could drive the MGUK directly from the MGUH, but its output would not be controlled?

The power would be whatever the MGUH delivered, the speed would be dependent on the MGUH and not have a relationship to what the driver actually demands.

Maybe they can "fill" the gaps with the ES. I don't even know if the rules allow it or if is physically possible to do so.

Joseki wrote:

wuzak wrote:Surely you could drive the MGUK directly from the MGUH, but its output would not be controlled?

The power would be whatever the MGUH delivered, the speed would be dependent on the MGUH and not have a relationship to what the driver actually demands.

Maybe they can "fill" the gaps with the ES. I don't even know if the rules allow it or if is physically possible to do so.

I don't see why the control electronics wouldn't up to the task.

I guess some things never change. When I was at Honda decades ago, we would see things in the press written about us wondering where this "news" came from. A lot of it was pure speculation as I am guessing that latest article in the Italian publication is now. This is what I know, if Honda was having severe reliability issues, they are not going to reveal that to anyone...no one.... This is also what I understand, Honda is very pleased with the progress they have made overall. They are more than pleased with the ICE. They have a completely redesigned turbine, compressor and MGU-H unit. That's what I understand for now. I have asked more than once about dyno runs and even my close contacts are tight-lipped but they do smile when I ask and to me.....that's a good sign.

But until the MP4-31's tires see the Barcelona pavement, we really don't know.

godlameroso wrote:You're the one that keeps saying you can't think of these engines as just turbocharged engines, you are not even considering why the turbo needs to be sized in this specific way. I'll let you explain why moving to larger more efficient turbos would help heat recovery then. I promise I won't say another word on the subject, just please answer me this, why does a larger more efficient turbo aid heat recovery?

The reason Mercedes is going to a bigger turbo this year is - they need more airflow. They have found some improvements in the combustion area which is allowing a leaner AFR and probably higher cylinder pressures. The larger turbo might be a fraction of one percent more efficient due to the increase in size. There is no big power increase to be had from the minute efficiency increase that goes with a larger compressor or turbine. On the other hand, if the size is arbitrarily increased so that the flow capacity is no longer a perfect match for the engine airflow, there will be a large loss of efficiency. Have another look at the map. The best efficiency is only obtained over a very small range of flow (x-axis) and boost (y-axis).

The reason Honda is going to a bigger turbo this year is - they got it wrong last year.

Turbine sizing is a similar situation BTW. The mass flow and temperature of exhaust gas will dictate the size (swallowing capacity) of the turbine. From there, the engine developer will select the turbine housing to find the best compromise between - "low back pressure" (good for engine power) and "high back pressure" (good for turbine power). There is a lot of talk about using a "bigger turbine" to make more MGUH power but the fact is "more turbine power" requires a smaller, more-restrictive turbine nozzle (turbine housing).

Wazari wrote:I guess some things never change. When I was at Honda decades ago, we would see things in the press written about us wondering where this "news" came from. A lot of it was pure speculation as I am guessing that latest article in the Italian publication is now. This is what I know, if Honda was having severe reliability issues, they are not going to reveal that to anyone...no one.... This is also what I understand, Honda is very pleased with the progress they have made overall. They are more than pleased with the ICE. They have a completely redesigned turbine, compressor and MGU-H unit. That's what I understand for now. I have asked more than once about dyno runs and even my close contacts are tight-lipped but they do smile when I ask and to me.....that's a good sign.

But until the MP4-31's tires see the Barcelona pavement, we really don't know.

Thanks Wazari san. Do we have any info on the ERS? Have Honda managed to resolve this issue. I believe ERS will be a make or break for McLaren Honda this year as it will give an instant 1+ sec performance gain.

The only thing I know about the ERS is that Honda knew where they went wrong last summer. Ultimately after everything was said and done, the output from the turbine was too low, the compressor required too much draw from the MGU-H in motor mode and a little short on boost for the ICE and the MGU-H was "sized" incorrectly. They have been working to resolve these issues since August. I am guessing that was enough time to go from drawing board to implementation. No one knows except those on the inside. I agree that resolving this ERS problem is key to fix 80% of the PU's shortfall suffered last season.

Marca is reporting some idiotic rumors: Honda has a pool of 8 complete power units just for testing.

https://twitter.com/svandoorne/status/6 ... 8691240961 Do F1 simulators also have an engine? Wanted to know if 100+ laps covered by Vandoorne have any significance with Honda engine reliability.

damager21 wrote:https://twitter.com/svandoorne/status/6 ... 8691240961 Do F1 simulators also have an engine? Wanted to know if 100+ laps covered by Vandoorne have any significance with Honda engine reliability.

no, those simulators are fully digital. Engine maps can probably be optimized in the sim though

bw1235 wrote:

basti313 wrote:

Tommy Cookers wrote:the '120 kW' power limit of the MGU-K is defined as DC power draw
and there is no demand for mechanical measurement in this regard

More precisely a DC measurement. The effective voltage and the current over a shunt...no loss.
The question is, how this is done in reality. I assume they have the necessary voltmeters on the power outlet of the control unit.

Tommy Cookers wrote: but the rules do not demand a wholly DC system
they leave what could be seen as an open door to energise its electric motor action at higher power via a non-DC, non-storage route

and there's no actually overwhelming reason to render all propulsion electrical energy streams DC at some point
eg if the future of humankind depended on it being a no-DC system, it could be so done

No, the frequency is always different. There is no way to drive the K with the H without an inverter.

Granted it sounds like a heinous problem to solve (with the juice possibly not worth the squeeze), but since there can be a fixed ratio applied to gear the -H and -K, could you not design for a state where they were both turning very close to the same speed as the car approaches terminal velocity? At that point, the control system for the -H could lock it's speed to the -K and the 3-phase AC could be routed directly between them. The boost would vary slightly as velocity changes, (or the -H's clutch could be modulated slightly?). In other states, a DC route could be used to charge the ES. That same DC route could also load the -H appropriately to charge the ES with any energy the -K cannot utilize.

SO.... probably not

No. The K is linear with speed, the H is not at all linear. There is no way to keep a certain ratio.