Mercedes Power Unit Hardware & Software

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
Big Tea
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Re: Mercedes Power Unit Hardware & Software

Post by Big Tea » Fri Aug 10, 2018 7:46 pm

Laserguru wrote:
Fri Aug 10, 2018 5:20 pm
MGU-H can send as much power as it wants to the MGU-K as long as it goes through the MGU control unit (which has a maximum storage of 5KJ).

Assume Magneti Marelli's MGUH produces 90kW.

When thinking of a twin battery, as Ferrari seems to do according to FIA, you could imagine the MGU control unit as a secondary battery. So one big battery of 4MJ and a small one of 5KJ which is not called a battery (loophole).

MGUK energy to battery is max 2MJ per lap.
Battery energy to MGUK is max 4MJ per lap.
MGUH energy to MGUK is unlimited but must go through the MGU control unit.
MGUH energy to battery is unlimeted in both directions.

Maximum 120kW (160bhp) energy deployment limit between the MGU-K and the internal combustion engine. Full throttle for 4MJ/120kW=33.333s and your battery is depleted.

At any time the battery is fully charged with 4MJ you can harvest/store/deploy 5kJ from the MGUH through the MGU control unit ‘battery’ to the MGUK.
A propulsion boost of arbitrary 40bhp or 30kW is possible during 5kJ/30kW=167ms. It takes the MGUH 5KJ/90KW=56ms to harvest the excess energy.
This can be done at any circuit where you can harvest more than 2MJ per lap by MGUK and 2MJ by MGUH. Excess of 2MJ MGUH can be used in bits of 5kJ.

Imagine there are many corners and harvesting is plenty, every heavy breaking corner after lift and coast (battery 4MJ) you may ‘store’ MGUH energy in the MGU control unit for a whopping 167ms lasting 40bhp, deployed when accelerating out of a corner onto the straight. What does 40bhp for 167ms bring? A few kmh extra top speed? Faster acceleration out of the corners? Would be only a software update.
Is there any way that the 'other' part of the battery is connected directly to the 'store' only, so although it is passed and used by the main unit it is not c
classed as being above the limit?

If the maximum the 'store' in the control module is set, can they perhaps say, look, its from there and you have already measured it once?

This would be more of a temporary holding option than an extra shot, but stored at parts of the lap it could not be used anyway
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Tommy Cookers
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Re: Mercedes Power Unit Hardware & Software

Post by Tommy Cookers » Fri Aug 10, 2018 7:49 pm

the 5 kJ cannot physically be used to energise the K as has been claimed

even if there was some rule loophole it would only be physically applicable to some fraction of the 5 kJ
the 5 kJ capacitive energy store cannot physically be anywhere near fully drained by K motoring

Laserguru
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Re: Mercedes Power Unit Hardware & Software

Post by Laserguru » Fri Aug 10, 2018 10:55 pm

Tommy Cookers wrote:
Fri Aug 10, 2018 7:49 pm
the 5 kJ cannot physically be used to energise the K as has been claimed

even if there was some rule loophole it would only be physically applicable to some fraction of the 5 kJ
the 5 kJ capacitive energy store cannot physically be anywhere near fully drained by K motoring
Same discussion going on in the Ferrari PU & SW thread, I missed it, but more people thinking in this direction. So far I have not read an explanation why it could not be used. I agree it is not what you would expect, or what is common, but where you store energy you can retrieve it any time you want.

Ok parttially seems reasonable as there are many functions in the MGU control unit. MGU control unit distributes/switches and matches voltages/currents, inverter, and controls ES charge/discharge. 5kJ is a massive amount. Energy can be stored in an inductor, transformer or capacitor.

Would require inside knowledge of the MGU control unit as to what can and cannot be done. No clue how the configuration and usage of the electronics is.

Assume the MGU control unit use multiphase switching SiC FETs and low capacitive inductors. Energy could be mostly stored in these inductors then? Not in capacitors? Or transformers? Many topology options, but 5kJ is massive.

You can completely drain the MGU control unit path between MGUH and ES diverted towards MGUK when ES is full and there is little power coming from MGUH. Stop switching at the input charging and drain from the output. Will exponentionally decrease the output current of course but you can drain the stored energy completely. Next you would have to go through the rush in behaviour of the converter input stage but that can be done whenever there is energy available from the MGUH. This energy cannot go to the MGU control unit at rush-in so you lose a little charge towards the ES, but it will be compensated later maybe during lift and coast or better during braking for corner entry.

Imagine unplugging the 240V of your power brick and the led will continue to burn far a while intensity fades as the discharge proceeds. Stored energy used. Once you plugin the 240V you may switch of the led before but a large rush in will charge the switching capacitors. In the MGU control unit the oscillators and other electronics remain powered and only the switched inductive/capacitive elements will be drained or charged.

In normal operation this is never done even with multi phase dc/dc to avoid high ripple, but you can do it I would say. Five times per lap seems doable. When you fulfill the prerequisites of having excessive energy harvesting due to track layout to overcome the multiple rush-in.

I maybe wrong but it was a nice exercise considering it. How much lap time or top speed it will bring is not my comfort zone.

Edit: corrected ECU to MGU control unit as pointed out by Skippon
Last edited by Laserguru on Sat Aug 11, 2018 7:28 pm, edited 2 times in total.
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Skippon
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Re: Mercedes Power Unit Hardware & Software

Post by Skippon » Sat Aug 11, 2018 2:06 pm

The ECU (MAT TAG320) does not directly drive anything... it is merely the PU coordinator, logger and comms hub. the motor drives H and K are a separate bunch of electronics control and drivers!!!

Laserguru
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Re: Mercedes Power Unit Hardware & Software

Post by Laserguru » Sat Aug 11, 2018 7:23 pm

Skippon wrote:
Sat Aug 11, 2018 2:06 pm
The ECU (MAT TAG320) does not directly drive anything... it is merely the PU coordinator, logger and comms hub. the motor drives H and K are a separate bunch of electronics control and drivers!!!
Thx, ECU supposed to be the MGU control unit as I wrote in my initial post. :lol: At my age you start mixing names.
Do you know the details of the MGU control unit, or are the electronics control and drivers distributed and is it only conceptual in FIA regulations?
Any idea what the total 5kJ of the MGU control unit itended use is?
Engineering thrives on communication.

GrandAxe
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Re: Mercedes Power Unit Hardware & Software

Post by GrandAxe » Sat Aug 11, 2018 8:33 pm

Laserguru wrote:
Sat Aug 11, 2018 7:23 pm
Skippon wrote:
Sat Aug 11, 2018 2:06 pm
The ECU (MAT TAG320) does not directly drive anything... it is merely the PU coordinator, logger and comms hub. the motor drives H and K are a separate bunch of electronics control and drivers!!!
Thx, ECU supposed to be the MGU control unit as I wrote in my initial post. :lol: At my age you start mixing names.
Do you know the details of the MGU control unit, or are the electronics control and drivers distributed and is it only conceptual in FIA regulations?
Any idea what the total 5kJ of the MGU control unit itended use is?
All ERS system components; batteries, controllers and software are built by the teams.

In the energy flow diagram, all relevant paths (MGU-H to ES, MGU-K to ES and MGU-H to MGU-K) flow through the MGU control unit. Therefore (in my opinion), it is a transit point, which can only be a combination of control electronics and (inferring from its KJ energy units) a secondary energy store (even if transient).

There is also the 300kj non-ERS storage whose use is unspecified and is outside of all flow loops. The non-ERS storage has a single limitation; that if drawn at greater than 2kw, only a max of 20kj can be stored.

Lots of interesting scenario's!

Laserguru
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Joined: Wed Dec 27, 2017 4:12 pm

Re: Mercedes Power Unit Hardware & Software

Post by Laserguru » Sun Aug 12, 2018 1:10 pm

GrandAxe wrote:
Sat Aug 11, 2018 8:33 pm
Laserguru wrote:
Sat Aug 11, 2018 7:23 pm
Skippon wrote:
Sat Aug 11, 2018 2:06 pm
The ECU (MAT TAG320) does not directly drive anything... it is merely the PU coordinator, logger and comms hub. the motor drives H and K are a separate bunch of electronics control and drivers!!!
Thx, ECU supposed to be the MGU control unit as I wrote in my initial post. :lol: At my age you start mixing names.
Do you know the details of the MGU control unit, or are the electronics control and drivers distributed and is it only conceptual in FIA regulations?
Any idea what the total 5kJ of the MGU control unit itended use is?
All ERS system components; batteries, controllers and software are built by the teams.

In the energy flow diagram, all relevant paths (MGU-H to ES, MGU-K to ES and MGU-H to MGU-K) flow through the MGU control unit. Therefore (in my opinion), it is a transit point, which can only be a combination of control electronics and (inferring from its KJ energy units) a secondary energy store (even if transient).

There is also the 300kj non-ERS storage whose use is unspecified and is outside of all flow loops. The non-ERS storage has a single limitation; that if drawn at greater than 2kw, only a max of 20kj can be stored.

Lots of interesting scenario's!
According to FIA 2018 F1 Technical Regulations that non-ERS storage can only source energy from the ERS and can only supply ‘other ancillaries’?

It is understood Mercedes uses a single battery concept in the ES and Ferrari a twin battery, and 2018 regulations specify 2 control units: 1x for MGU-K called CU-K, 1x for MGU-H called CU-H. Could Ferrari store 2x5kJ and Mercedes 1x5kJ? FIA states 5kJ in the MGU CU but what if you read 5kJ CU-K and 5kJ CU-H? Can imagine some would declare this illegal (Mercedes) some would declare this legal (Ferrari)? Noticed that FIA states ‘single MGU-H’ and ‘single MGU-K’ but where they specify the 5kJ write a rather unspecified ‘MGU-CU’...

Or could it be that due to the parallel nature of Ferrari (ES twin battery, split CU) they can simply charge their ES in a shorter time? Can imagine this will be beneficial. Mercedes interfaces one battery to both CU-H and CU-K which, given a maximum 400V, would create a potential bottleneck.

As I start to learn there are so many options to control the energy flow, I can imagine that you can make a difference here.

Mercedes engineers have the holiday to think their concept over, whilst enjoying their vacation.
Engineering thrives on communication.