Don't forget regen during descent! You have to bleed off a lot of speed; why use drag when you can recharge for your next takeoff?
I'd have range anxiety in a plane too
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regen would be nice for dipping in and out of different altitudes for sight seeing, you'd also be able to probably recharge enough when gliding out of high altitudes for a guaranteed 'power on' landingDon't forget regen during descent! You have to bleed off a lot of speed; why use drag when you can recharge for your next takeoff?
I'd have range anxiety in a plane too
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*battery density is only a minute part of the grand scheme of things when you account for the fact that the battery pack in this electric setup are almost the only item that is of significant weight
*this weight however is >5x the size of the Gasoline storage weight of an ICE setup of which the gasoline only takes up non majoritive proportion of the weight therefore a full gas tank only goes >4x the distance of a full ev pack
*Gas motors aren't always that efficient under a high torque load such as propellers especially when you take into account changing wind fronts, bad weather, takeoffs, acceleration, stall recovery, reduction drives,alternators and water pumps. Also there are inefficiencies associated with ICE motor propellers since they are many of the time designed in a way that makes a (efficiency) sacrifice to obtain a combination of climbing (acceleration) and cruising power since its peak operating power is not achieved across the entire power band.
*any energy from grid is over 4x cheaper then gas fuel with a growing margin of separation, also if plugged into a solar/biogas powered home the incentives for using plug in power increases many fold
-Cleanly fuel source
-efficient
-CHEAP
**Last but not least the Hi Power low weight generator, is supposed to be a RANGE EXTENDER not the main source upon which the vehicle flys . The MAIN POWER SOURCE is the energy from the grid. by supplementing the smallest amount of gas needed for the trip you can essentially fly Solely on Cheap grid power. medium and and long trips would still be feasible on small portions of fuel (think in terms of 0.25-3 gallons of NON-AVIATION FUEL$$).
the small generator engine would work together with a low drag electric high efficiency generator aka small axial flux Ac motor. and due to lack of moving high load parts attached to the motor like in typical ICE setups, it would make more usable power and therefore more output energy
Yeah i'm pretty sure the idea would work fine . i'm going to do it in car first , then plane trials thereafter.
i was wanting input on how to operate max regen abilities with ac motor. Or in other words how to use its exclusively as a generator, and are they reliable when used in that way.
Anything you design for
You either charge the battery or discharge it or don't use it at all. If you generate more power than your motor is using, then you charge the battery. If the motor power is greater than the generator output, the battery discharges.
A glider with the brakes out (regenerating via the prop in your case) drops like a stone to maintain airspeed, maybe 800'/minute as best I can estimate for what I fly without actually timing a descent. You may do a little better given air brakes also spoil the airflow but I'd not count on it.
Earlier on you mentioned the generator engine making more power because there isn't a high braking torque applied (propeller). Perhaps I misread you but if there's not a high braking torque applied it's not making high power, it's just freewheeling burning a little fuel to overcome internal friction and pumping losses, you get nothing for free. Your planned generator is still driving the prop (or the pack) albeit indirectly through a drive system that's a lot heavier and lossier than a simple reduction belt drive. Yes, you could with careful control manage the engine to maintain peak efficiency (which you'll need to determine for a variety of load/rpm/altitude conditions) but then you could also do that with a variable pitch prop. That's traded against the inefficiency of flying with a couple of degrees extra AOA to carry batteries and motors.
All the losses associated with hard driven propellers operating away from their optimum conditions while climbing or flying fast still exist with your hybrid drive, they're just multiplied up by the low system efficiency so you burn more fuel. You'll have a real challenge on your hands to rival the efficiency of a light engine in a light airframe (no batteries) belt driving a prop. Doing it safely and at a cost where you see any return on investment vs the standard engine would be a hell of an achievement.
A direct/belt driven alternator sized (and likely re-wound) for your generating requirements will be the simplest way to implement a generator, the control is simpler than for PMDC, the high voltages/currents are all handled by simple diodes, the controller is a low power device.
Doing it in a car is far easier, the added weight doesn't contribute to the losses or structural problems in anything like the same way. The pulsed power delivery is quite different too allowing undersized, overloaded parts cooling time. When it lets the smoke out you can walk away from it
thanks for the 'real world practicality' food for thought
-You did not misread me , i was just WRONG about the brake torque part lol i had some wires twisted
correct me if im wrong but i dont think all of thats necessary, why not just find peak ICE torque. find light scooter/vehicle PMAC with compatible regen rpm range. Turn up its regen to max. then have 3 preset throttle positions , hi, mid ,lo . then for motorsoaring short distances (<140mi) use no generator and then use the modes incrementally as needed to extend range beyond that.
using the standard that electric vehicles get a rough equivalent of 4x the mpg(e) of a gas vehicle; if a gas plane hypermiling gets 55-60mpg at around 65-80 then a ev could get a equivalent of 220-240mpg using Grid electrcity.
even if my generator only put out an equivalent 40mpg to a ICE with a propellers 60mpg i would still be highly advantageous because i would have barely used the generator during the trip.
If i had a battery pack that will go 240miles total, if i use my a range extender at roughly 40mpg for 2 gallons aka 80 miles i would get an equivalent of 106mpg for my trip of 320miles. and thats if my generator at peak efficiency was a 2/3 the efficiency of an ICE motor with propeller,water pump,alternator, with and wind conditions
do you think that would be simpler,more efficient,more flexible then a PMAC In generator mode?
edit- i decided a bit ago that a second emrax is overkill for the generator unit but a smaller a lighter axial flux could easily do the job such as a perm motor- https://docs.google.com/spreadsheet/ccc?key=0AhtFYXutdAAHdE85anpENjVPamwzLTFIZUdHY1hJM2c#gid=0 or atleast something like it
true that but then your not flying lol and you cant drive a car over water or mountains or anything besides roads and some off roadsDoing it in a car is far easier, the added weight doesn't contribute to the losses or structural problems in anything like the same way. The pulsed power delivery is quite different too allowing undersized, overloaded parts cooling time. When it lets the smoke out you can walk away from it
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