MGU-H/MGU-K/energy store mix

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
trinidefender
317
Joined: 19 Apr 2013, 20:37

MGU-H/MGU-K/energy store mix

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Ok a quick question primarily to the electrical engineering types.

Would it be possible to simultaneously power the MGU-K with the battery and the MGU-H. Such as 60 kW from the battery and 60 kW from the MGU-H both powering the MGU-K at the same time?

In our helicopter we have 2 DC generators but because of voltage differences etc each generator is only powering certain buses at any one time. Should the voltage drop on any bus then the electric bus tie will swap the bus and put it onto the other generator. So to relate this to my F1 question. We don't have the capability to power one bus with two sources in the helicopter. Is it in some way possible in F1 with the battery, MGU-H and MGU-K? Unless I am missing something it shouldn't be due to even tiny fluctuations in voltage.

chip engineer
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Joined: 28 Apr 2013, 00:01
Location: Colorado, USA

Re: MGU-H/MGU-K/energy store mix

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trinidefender wrote:Ok a quick question primarily to the electrical engineering types.

Would it be possible to simultaneously power the MGU-K with the battery and the MGU-H. Such as 60 kW from the battery and 60 kW from the MGU-H both powering the MGU-K at the same time?
Yes, probably several ways to do that.
Maybe not the best or most efficient way, but the easiest to visualize is this:
Use the MGU-H power to charge the battery with say 60 kW. At the same time, take 120 kW from the battery to power the MGU-K. This is even easy on the battery, since it mostly just has to provide 60 kW.

trinidefender
317
Joined: 19 Apr 2013, 20:37

Re: MGU-H/MGU-K/energy store mix

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chip engineer wrote:
trinidefender wrote:Ok a quick question primarily to the electrical engineering types.

Would it be possible to simultaneously power the MGU-K with the battery and the MGU-H. Such as 60 kW from the battery and 60 kW from the MGU-H both powering the MGU-K at the same time?
Yes, probably several ways to do that.
Maybe not the best or most efficient way, but the easiest to visualize is this:
Use the MGU-H power to charge the battery with say 60 kW. At the same time, take 120 kW from the battery to power the MGU-K. This is even easy on the battery, since it mostly just has to provide 60 kW.
This i can understand and also something I thought of. However I'm not sure if the regulations are set up to allow this. The regulations say that if the battery is powering the MGU-K then there is a 120 kW power limit. If the MGU-K is fed this 120 kW then it can only do so for a little over 33 seconds. The original idea is so that the MGU-H can provide some of the energy requirements so that the battery only has to run at half load or whatever it takes for the MGU-K to be running at 120 kW the whole lap.

Understand what I mean or did I lose a grasp of the English language....?

chip engineer
21
Joined: 28 Apr 2013, 00:01
Location: Colorado, USA

Re: MGU-H/MGU-K/energy store mix

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trinidefender wrote:
chip engineer wrote:
trinidefender wrote:Ok a quick question primarily to the electrical engineering types.

Would it be possible to simultaneously power the MGU-K with the battery and the MGU-H. Such as 60 kW from the battery and 60 kW from the MGU-H both powering the MGU-K at the same time?
Yes, probably several ways to do that.
Maybe not the best or most efficient way, but the easiest to visualize is this:
Use the MGU-H power to charge the battery with say 60 kW. At the same time, take 120 kW from the battery to power the MGU-K. This is even easy on the battery, since it mostly just has to provide 60 kW.
This i can understand and also something I thought of. However I'm not sure if the regulations are set up to allow this. The regulations say that if the battery is powering the MGU-K then there is a 120 kW power limit. If the MGU-K is fed this 120 kW then it can only do so for a little over 33 seconds. The original idea is so that the MGU-H can provide some of the energy requirements so that the battery only has to run at half load or whatever it takes for the MGU-K to be running at 120 kW the whole lap.

Understand what I mean or did I lose a grasp of the English language....?
Yeah, I was just looking at that too. It might be interpreted that only 1/2 of the energy is really coming from the battery, so the rule only applies to that half.
But there are other ways:
Have 2 sets of windings on the MGU-K, one powered by the battery, one by the MGU-H. This would get around the battery energy per lap rule, and should be fairly easy to control, but probably increases the MGU-K weight a little.
Another way would be to put MGU-H voltage in series with the battery. Much trickier to make work properly, and especially difficult to control how much power comes from each source.

wuzak
434
Joined: 30 Aug 2011, 03:26

Re: MGU-H/MGU-K/energy store mix

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The power has to go through a controller/inverter which converts battery DC to AC and the MGUH's frequency to that which is required by the MGU-K at the time.

trinidefender
317
Joined: 19 Apr 2013, 20:37

Re: MGU-H/MGU-K/energy store mix

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wuzak wrote:The power has to go through a controller/inverter which converts battery DC to AC and the MGUH's frequency to that which is required by the MGU-K at the time.
Oh. Well that clears things up a little. For some reason I had it in my head that the MGU-K was DC powered in my thought process. So basically the battery's power goes through the controller as well and both waves are overlapped onto each other?

wuzak
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Joined: 30 Aug 2011, 03:26

Re: MGU-H/MGU-K/energy store mix

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trinidefender wrote:
wuzak wrote:The power has to go through a controller/inverter which converts battery DC to AC and the MGUH's frequency to that which is required by the MGU-K at the time.
Oh. Well that clears things up a little. For some reason I had it in my head that the MGU-K was DC powered in my thought process. So basically the battery's power goes through the controller as well and both waves are overlapped onto each other?
I would think so.

bergie88
8
Joined: 25 Aug 2014, 12:20

Re: MGU-H/MGU-K/energy store mix

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I think both the MGU-K and MGU-H are AC electric motors, so they both need a controller to convert from AC to DC or viceversa (powering/regenerating), since the battery is DC. At some point in the electric circuit all power is DC current, where it is the question if all this DC current is flowing into the battery or not. I dont know exactly how, but there must be a way to power the MGU-K lets say half by the battery and half directly from the MGU-H. In this way the rule of maximum energy from the battery can be circumvented.

trinidefender
317
Joined: 19 Apr 2013, 20:37

Re: MGU-H/MGU-K/energy store mix

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bergie88 wrote:I think both the MGU-K and MGU-H are AC electric motors, so they both need a controller to convert from AC to DC or viceversa (powering/regenerating), since the battery is DC. At some point in the electric circuit all power is DC current, where it is the question if all this DC current is flowing into the battery or not. I dont know exactly how, but there must be a way to power the MGU-K lets say half by the battery and half directly from the MGU-H. In this way the rule of maximum energy from the battery can be circumvented.
You aren't circumventing the rule. The rule is still being adhered to about maximum energy from battery to MGU-K. It is just that by reducing the amount energy over a set period of time you can keep supplying electricity (energy) for a longer period of time. The maximum energy limit is still there. The rest of the energy not being supplied by the battery is then supplied by the MGU-H

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Pierce89
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Joined: 21 Oct 2009, 18:38

Re: MGU-H/MGU-K/energy store mix

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The answer is yes. Think of it this way: Coming off of a corner, they will use the mgu:k for thrust and use the mgu:h to spool up the turbo, at the same time.
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trinidefender
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Joined: 19 Apr 2013, 20:37

Re: MGU-H/MGU-K/energy store mix

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Pierce89 wrote:The answer is yes. Think of it this way: Coming off of a corner, they will use the mgu:k for thrust and use the mgu:h to spool up the turbo, at the same time.
That does actually answer my question and I believe it doesn't actually work like that. If that happened and the battery was used to provide the full 120 kW for that time period then at some point during the lap, after 33 seconds of full MGU-K power then the MGU-H would start to harvest energy from the exhaust to send power straight to the MGU-K.

That idea presents some problems.
1. When the battery has reached its energy limit to send to the MGU-K then judging by preliminary calculations it wouldn't be possible to harvest 120 kW from the MGU-H to send to the -K even in peak generating conditions.
2. The turbo would have to be spooled before full throttle is applied. To obviously prevent lag and more importantly once full throttle is applied and the turbo is spooled, to harvest excess energy from the MGU-H.
3. If the battery is putting out the full 120 kW to the MGU-K then either the MGU-H will have to waste any energy it is generating or the wastegate will have to open.....wasting energy.

What I, and it seems others, think is far more likely is that in a corner the turbo is pre-spooled by the MGU-H. As soon as the throttle is applied the battery supplies some of the required 120 kW to the MGU-K. Say 60 kW for this example. The other 60 kW is made by harvesting from the MGU-H. As the car is already at full throttle and the turbo is fully spooled up, excess energy be created. It is this excess energy from the MGU-H that will then be sent directly to the MGU-H to fill the other 60 kW.

langwadt
35
Joined: 25 Mar 2012, 14:54

Re: MGU-H/MGU-K/energy store mix

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bergie88 wrote:I think both the MGU-K and MGU-H are AC electric motors, so they both need a controller to convert from AC to DC or viceversa (powering/regenerating), since the battery is DC. At some point in the electric circuit all power is DC current, where it is the question if all this DC current is flowing into the battery or not. I dont know exactly how, but there must be a way to power the MGU-K lets say half by the battery and half directly from the MGU-H. In this way the rule of maximum energy from the battery can be circumvented.
it is no different than if you charge you cellphone/laptop etc. while you are using it, it will take longer to charge because some of the charging current goes to running it instead charging the battery

the AC/DC part doesn't really matter, there is little difference between AC and DC motors, in principle the controller
just replaces the mechanical switching done by the commutator in a DC motor with electronic switches

wuzak
434
Joined: 30 Aug 2011, 03:26

Re: MGU-H/MGU-K/energy store mix

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trinidefender wrote:
Pierce89 wrote:The answer is yes. Think of it this way: Coming off of a corner, they will use the mgu:k for thrust and use the mgu:h to spool up the turbo, at the same time.
That does actually answer my question and I believe it doesn't actually work like that. If that happened and the battery was used to provide the full 120 kW for that time period then at some point during the lap, after 33 seconds of full MGU-K power then the MGU-H would start to harvest energy from the exhaust to send power straight to the MGU-K.
Be aware that the MGU-K activation is not an on-off switch like the KERS of the past. It responds to the driver's request for power - the ECU determining how to give that power, in what combination of ICE and MGU-K. I think it is likely that exiting slow corners will use only a portion of MGU-K power and not the full 120kW.

Teh full 120kW would only be deployed on the straights - ie when traction is sufficient to support full power.

J.A.W.
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Re: MGU-H/MGU-K/energy store mix

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Would not the ergs be phased into shaft output - to infill the ICE torque deficit - at points below the optimum curve?
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in good Kiwi style - riding a Massey Ferguson farm
tractor - with a few extemporised mod's to hack the task).

chip engineer
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Location: Colorado, USA

Re: MGU-H/MGU-K/energy store mix

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wuzak wrote: Be aware that the MGU-K activation is not an on-off switch like the KERS of the past. It responds to the driver's request for power - the ECU determining how to give that power, in what combination of ICE and MGU-K. I think it is likely that exiting slow corners will use only a portion of MGU-K power and not the full 120kW.

Teh full 120kW would only be deployed on the straights - ie when traction is sufficient to support full power.
That would make sense if traction control was not a consideration. But I suspect that there are legal traction control benefits to using as much MGU-K as possible when traction limited. Then when wheel-spin occurs, the natural operation of an electric motor to increased rpm automatically reduces its torque output to help stop the wheel-spin.