Series hybrid... suitable generator?

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blodnatt117
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Would anyone be able to inform me as to where I might find a suitable generator to use in a series hybrid configuration? Is is possible to use a electric vehicle motor?

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Gman
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Re: Series hybrid... suitable generator?

`I believe in a series hybrid system, the combustion engine drives an electric generator instead of directly driving the wheels. The generator both charges a battery and powers an electric motor that moves the vehicle. When large amounts of power are required, the motor draws electricity from both the batteries and the generator. A complex transmission is not needed, as electric motors are efficient over a wide speed range. Some vehicle designs have separate electric motors for each wheel. Series hybrids can be also be fitted with a supercapacitor or a flywheel, which can improve efficiency by minimizing the losses in the battery.

The advantage of a series hybrid is the lack of a mechanical link between the combustion engine and the wheels. The combustion engine runs at a constant and efficient rate, even as the car changes speed. During stop-and-go city driving, series hybrids are relatively the most efficient.

A weakness is that the power from the combustion engine has to run through both the generator and electric motor. During long-distance highway driving, the electrical transmission can be less efficient than a conventional transmission.

The use of one motor per wheel eliminates the conventional mechanical transmission elements (gearbox, transmission shafts, differential). If the motors are integrated into the wheels, the unsprung mass increases, decreasing ride performance. If the motors are attached to the vehicle body, flexible couplings are required. Advantages of individual wheel motors include simplified traction control and all wheel drive, and allowing lower floors, which is useful for buses. Some 8x8 all-wheel drive military vehicles use individual wheel motors.

Structure of a series hybrid vehicle
800px-Hybridpeak.png

In a series hybrid bicycle (SH) the user powers a generator using the pedals. This is converted into electricity and can be fed directly to the motor giving a chain less bicycle but also to charge a battery. The motor draws power from the battery and must be able to deliver the full mechanical torque required because none is available from the pedals. SH bicycles are not yet commercially available. They will become feasible if extremely high-efficiency generators and motors are available at competitive prices, especially for recumbent bicycles and tandems, where problems associated with the complexity of a long chain drive can be avoided.

Peace Out,
Gman

Now that we have clarified our beliefs, your invited to join us as we begin building on them to define our Community Mission Statement

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Gman

reikiman
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Re: Series hybrid... suitable generator?

Yes.. series hybrid the gas motor is there only to charge the battery pack. In a parallel hybrid the gas motor is also connected to the wheels through in parallel with the electric motor. FWIW Ferdinand Porsche's first car was a series hybrid electric -- in the early 1900's -- it had hub motors in each wheel, with a gas generator for the battery pack, and he set land speed records with it (whopping 65 miles/hr if I remember right).

Anyway, you don't say what size vehicle you have in mind and what the range considerations are.

My eye has been on the Honda generators because their motor is 4-stroke. Honda builds a series of small 4-stroke motors that are as small as 31cc. The smallest generator they sell is using the 50cc version of the motor. 4-stroke is gonna be less stinky or less polluting than a 2-stroke. The size vehicle in my case is an electric motorcycle and the fuel would be stored in the regular gas tank on the motorcycle, and the idea is to use the generator to help give long range.

- David Herron, http://davidherron.com/

__________________

- David Herron, Green Transportation Examiner, Green Transportation Info, The Long Tail Pipe, Electric Race News, davidherron.com, 7gen.com, What is Reiki
- Charger bike (rebuilt), Electrified Electra Townie, 1971 Karmann Ghia

dwangyahoo
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Re: Series hybrid... suitable generator?

I'm not an expert, so perhaps someone who knows more can point out the limitations and bad assumptions below.

What if you just get a consumer portable generator from Pepboys, you can easily get a 5000 watt for a few hundred bucks. Then put a full wave bridge across it. The 110vac will become 155vdc at the peak but drop down fairly quickly since it's only 60Hz. Since it's only 5000 watts, it's undersized for the the battery pack and the EV's motor, so the 155vdc will get pulled down to whatever voltage your battery pack is at. So you've just hybridized your EV for a just a few hundred bucks!

Russ
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Re: Series hybrid... suitable generator?

Go to the bottom of this link and watch the video. A generator is being used to drive an electric motor. The crank on the motor rotates only 60% of a revolution for every revolution of the generator. Hook your bike crank to a generator that drives a front hub motor and you will find that four out of every ten crank rotations will be thrown away by the inefficiency of the generator motor couple.

I looked into using a small generator in a bike trailer running on a tank of propane to make my bike into a series hybrid. The generator weighs 25 pounds, the propane tank about ten. Too much weight to carry around just for back up when the batteries go dead and way to inefficient to use as a moped engine. A scooter would use 40% less gas. I gave up on the idea when I realized that the generator would barely put out enough amps to run my bike once the batteries were sucked dry any way. So, now you can see the design challenges for a series hybrid car.

dwangyahoo
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Re: Series hybrid... suitable generator?

Russ, You are probably right that a generator motor couple is not very efficient. But out goal is not efficiency here. Our goal is to extend range so an EV is more useful for those occasional long trips. For the 80% of the short trips under 20 miles, we will not use the inefficient generator motor couple. But if we can cover those 20% long trips so more people can use an EV as their only vehicle, it will allow the EV industry to grow and R&D money put in to advance the EV technology.

Back to attaching a full wave bridge rectifier to a 5000 watt Pepboy portable generators to make a DC generator, what are the flaws in this approach? At 100 volts, the current will be 50 amps...are diodes expensive for these voltage and current specs?

Does anyone know how the new digital inverter generators work? Specifically, what is the value of the DC voltage before they invert it?

goodnslo
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Re: Series hybrid... suitable generator?

Dwangyahoo,
????Not about efficiency???? Every EV is built with power to weight ratio in mind, i.e.- whether adding more lead really helps or hinders a build. Russ makes a valid point and describes the design challenges of a series hybrid very effectively. Now, if you analyze what he said then you will recognize that the generator used did not fit the application. It would need a big improvement in efficiency to justify the added weight and the feasibility/hp. To improve this, there are a multitude of details that must be looked into, to include reducing weight.

Here are the primary areas that I see:
1. The electric generator would have to be rewound to match the rpm and hp of the ICE to closely match the optimum for the ICE. You dont want it bogged down from too strong a field and you dont want to be wasting the weight of the fuel by not running the ICE when it is most fuel efficient and effective.
2. You would have to choose a electric motor that would efficiently use the power as efficiently as possible with the hp performance to match the ICE power generator. Do you choose to go from AC directly from the generator or convert to DC and lose some efficiency due to rectifiers? Again it's about power, weight, and efficiency.
3. Power management is another issue that must be decided. It's not enough to just pick a regulator and hope it works. Do you charge the whole pack or individual batteries? Do you isolate the batts or produce enough extra power to use the motor as well as charge? Power regulation can also be a subpart of this. How much voltage created is optimum?
4. Finally, (although this might be a subset to the first) size of the power generator because the majority of power generation units are oversized for their application. Case in point, at my job, we use 15kw gens for systems that nominally operate in the 10kw range, but we have the added overhead to prevent voltage spikes and for when the added energy needed when temperatures drop. Now for driving, this would be equal to sudden acceleration when the batteries are near depletion (or are in the state of charging).

These are the areas that EV Research has to seriously consider.

dwangyahoo
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Re: Series hybrid... suitable generator?

Yes, EV is about efficiency, but no, this thread is not about efficiency. Because if this thread is about efficiency, we should not even try to build a SHEV because the SHEV will be wasting too much energy in the mechanical to electrical to chemical to electrical to mechanical conversions. If we are trying to be efficient, we should build a ICE pusher trailer or a parallel hybrid. But this thread is about what a DYI hobbist can easily do to extend the range of his BEV so it can be more useful. A ICE trailer is unwieldy. A parallel hybrid is complicated, just think about the Prius hybrid drive. However, adding a genset to a BEV is just a electrical pair of wires and a sturdy mounting. It will be inefficient, but it will extend the range and make the BEV much more useful.
This thread is about what can be used as a generator in a SHEV, despite the inefficiencies.
You're changing it to a discussion about the limitations and issues of a SHEV.

I suggested a commerically available portable generator because it already has matched RPM and power between the ICE to the generator head. Enough engineering went into it to balance the efficiency vs. cost. 5000 watts is low compare to the energy requirements of a BEV and it will not keep an EV running at highway speeds continuously, but any bigger will be less practical like Russ's Serial Hybrid bike. In fact, perhaps a smaller generator is the answer, since it will still enable longer trips by charging the battery for a few hours while the EV is sitting at the destination so the batteries are topped off as much as possible for the return trip.

Back to the subject...I am trying to explore the viability of a rectified portable generator because it's simple and cheap and easily achievable by DIYers. I hope people who know more about how these portable generators work can point out the wrong assumptions I made with the approach because if it's a viable approach, I want to try it myself.
For example, I learned that the new inverter generators uses an alternator that produces 3 phase AC, then it gets rectified into DC before the inverter changes it to 110VAC again. What is the voltage of the rectified DC? Can I just tap into the DC and connect it to the battery pack if the voltages match?

Regards,
Danny

goodnslo
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Re: Series hybrid... suitable generator?

I've used a 7.5Kw brushless gen from Onan often used in RV's and it operates just as described. Remember, the purpose of most of these gens is to provide stable power so that whatever system is being powered works as seamlessly as a commercial outlet and that is why it goes from AC to DC to AC again. The DC conversion does two things - provides a sensing voltage for the control circuitry to increase/decrease speed of the ICE motor and increase/decrease initial excite voltage, and evens out the initial AC voltage to a manageable range for the second AC conversion. In short, the DC voltage varies. IF tapping in, you will have to design whatever charging circuitry around that range. Usually, this is an all-in-one unit so there is the possibility of affecting the control circuitry.

dwangyahoo
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Re: Series hybrid... suitable generator?

goodnslo,

Do you mean you use it as a 110vac generator and plug the battery charger into it?
What is the size weight of the 7.5kw onan?
7.5kw is quite large, so the charger does not take full advantage of it, right?
What kind of battery charger do you use?
In your charger, it only allows charging when the vehicle is stopped, right?
Did you try anything to charge while the vehicle is moving?

Thanks,
Danny

dwangyahoo
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Re: Series hybrid... suitable generator?

Here's an article about SHEV.
www.greenhybrid.com/wiki/index.php/DIY_Hybrids:_An_Exciting_Possibility

However, it does not say what type of generator and best way to hook it up. That's what I'm hoping this thread will do.

andrew
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Re: Series hybrid... suitable generator?

Quote:

Would anyone be able to inform me as to where I might find a suitable generator to use in a series hybrid configuration? Is is possible to use a electric vehicle motor?

What size generator? What size vehicle?

There are some cheap generators on ebay. If you are going to rectify the output and send it straight to the batteries beware that the semi-dirty power could cause controller problems.

There are lots of other ways to extend range if that is your goal.
---
Avatar taken from http://www.electricmotorbike.org/
Anyone got one they might want to sell?
My KZ750 Project: here E.T.A. 1 mo

goodnslo
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Re: Series hybrid... suitable generator?

Dwangyahoo,

Do you mean you use it as a 110vac generator and plug the battery charger into it?
What is the size weight of the 7.5kw onan?
7.5kw is quite large, so the charger does not take full advantage of it, right?
What kind of battery charger do you use?
In your charger, it only allows charging when the vehicle is stopped, right?
Did you try anything to charge while the vehicle is moving?

Thanks,
Danny

At no time, did I say it was used on a vehicle. At work, we had used the generator to power equipment.

dwangyahoo
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Re: Series hybrid... suitable generator?

It seems no one is putting on a generator to extend range at this forum.
Finally, after lots of googling, I found a Canadian who used a 5kw induction motor as an induction generator and put it at the back of his S10.
It's in French:
http://www.vehiculevert.org/levehiculevert/index.php?lien=chevrolet

When I post the translated link, it doesn't work. So you can googe "Véhicule Vert", then click on the "translate this page" link.

Gman
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Re: Series hybrid... suitable generator?

``122a.jpg
1996 Chevrolet S-10 King-Cab
“Le Véhicule Vert”

Last Updated 02-05-2007
5 kilowatt DC generator
Owner Alain St-Yves
Owner's Other EV 1997 Chevrolet Cavalier
Location Salaberry-de-Valleyfield, Québec Canada map
Web WebPage
Vehicle 1996 Chevrolet S-10
extended cab
Motor Advanced DC FB1-4001 Series Wound DC
9"
Drivetrain Original 5 speed transmission
Controller Curtis 1231C-8601
Batteries 24 Trojan T 105, 6.00 Volt, Lead-Acid, Flooded
215 Ah
System Voltage 144 Volts
Charger Lester
two offboard, a 120 VDC and a 24 VDC both 30 Amp
1 Onboard, transformer isolated, 1500 Watts 120 VAC, timer controlled
Heater Custom made, 3 settings, 700,1400, and 2100 Watts
DC/DC Converter DC Power Systems DC-300
used with a 12 Volt battery
Instrumentation E-Meter
Top Speed 65 MPH (104 KPH)
generally used at 50 MPH (80 KPH)
Range 40 Miles (64 Kilometers)
electric only, up to 80 miles with 5kw generator assist. Range similar to conventional vehicle using 15 kw generator.
EV Miles
Start: 95,000 Miles (152,855 Kilometers)
Current: 140,000 Miles (225,260 Kilometers)
Total: 45,000 Miles (72,405 Kilometers)

As of 2/5/2007
Seating Capacity 2 adults and 2 children
Curb Weight 4,600 Pounds (2,090 Kilograms)
Tires Michelin X one 97 M+S max. 35 psi (I set at 40 psi)
Additional Features a) Battery compartment is insulated and heated with 6 regular battery heater of 50 watts each.
b) Bed Cover "Aerocover" brand, it's a light 3 section cover.
c) 5 kilowatt DC generator, installed in the truck bed if required for longer range. Driven by an ICE 11 HP Honda. Gas consumption, 3.5 litres/hour.

122f.jpg
5 kilowatt DC generator

122c.jpg

122b.jpg

Alain St-Yves took a slightly different approach (be sure to read the evlist excerpts at the bottom of the page). Instead of a pusher and instead of permanently mounting a gas engine in the vehicle, he created a range extending unit that he can pop into the back of his truck.

Peace Out,
Gman

Now that we have clarified our beliefs, your invited to join us as we begin building on them to define our Community Mission Statement

__________________

Peace Out,
Gman

spinningmagnets
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Re: Series hybrid... suitable generator?

Here's more info for your Series-Hybrid research file.

http://www.evnut.com/rav_longranger.htm
Toyota RAV S-H trailer

http://www.acpropulsion.com/tzero_pages/DSC00467.JPG
T-Zero with a S-H trailer

http://www.users.bigpond.com/solarbbq/bikeexp/bexp.htm
3-wheel bike with lawnmower engine/gen S-H

I've seen some of the new industrial "weed-wackers". I believe they were 50CC, and some of them are 4-stroke. I imagine these would be about the smallest practical engine to spin a generator (probably too small).

There are small engines in hardware stores of many sizes on water pumps, pressure-washers, etc, and there are 4-stroke motorcycle engines as small as 125CC.

I've no ideas about the generator or the controller and links.

reikiman
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Re: Series hybrid... suitable generator?

Quote:

I've seen some of the new industrial "weed-wackers". I believe they were 50CC, and some of them are 4-stroke. I imagine these would be about the smallest practical engine to spin a generator (probably too small).

Honda has a series of tiny 4 stroke engines which have decent emissions etc. IIRC the smallest is 31cc and they have a portable generator which uses the 50cc engine.

One time I visited Electric Motorsport Todd was working on mounting one of these engines in an electric motorcycle he was building. So it's not an unknown far-out idea. In fact on the old V (V.com) we had a brief conversation about that. IIRC when you buy one of these small Honda engines as a bare unit it's a pull start engine. But the portable generator built on the 50cc unit is an electric start. So I've always thought the easiest way to go would be getting the Honda portable generator based on their 50cc engine, and hack it up a bit for a bigger gas tank and some other reworking.

__________________

- David Herron, Green Transportation Examiner, Green Transportation Info, The Long Tail Pipe, Electric Race News, davidherron.com, 7gen.com, What is Reiki
- Charger bike (rebuilt), Electrified Electra Townie, 1971 Karmann Ghia

spinningmagnets
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Re: Series hybrid... suitable generator?

For some reason, I was thinking E-Bike, but after re-reading it sounds more like a series-hybrid CAR (the Honda 50cc gen sounds great for a bike, David!)

"...The US government funded a study to gather baseline data for a discussion of HEV theory. The experiments established it would take 17 Kw to maintain 65 MPH in an electric 2001 Ford Taurus. A recommended candidate for an Series-Hybrid APU was a Yamaha one-cylinder liquid-cooled 250 CC motorcycle engine, which was found capable of generating 30 KW from an appropriate generator.
Without any optimization of an engine design, this off-the-shelf APU was found capable of achieving 40 MPG in the aerodynamic mid-sized four-seat Taurus while using a modest-sized NiMH battery pack for Acceleration-Assist..."

http://www.webs1.uidaho.edu/niatt/publications/Reports/KLK331_files/KLK331.htm

This is from an article about University of Idaho, I just tried the link, but its old (2001) so, "object not found"

spinningmagnets
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Re: Series hybrid... suitable generator?

I've been thinking about this for a month or so, and the more I think about it, the more I like it.

I'm not promising I'll convert an EV, but I would really like to. I live 7 miles from work, and I don't have to drive on the freeway (only need 40 MPH) , so I really am a great candidate for an EV.

It would be nice to be able to travel farther if a situation warranted it. If I got a used VW rabbit with a lot of miles (I know where one is for $500), there are several books that could easily guide me through the conversion.

If I wanted to build a Series-Hybrid trailer for range extension, there are a wide variety of 110-120 VAC generators to choose from. Some are even affordably available used.

The trailer engine isn't a problem, whether diesel or gasoline, there is a wide variety that are affordably available used.

I've noticed the trend to have the highest voltage possible that is practical for your configuration and performance goals, but I'm assuming the trailer really should put out a higher voltage than the battery pack.

I've noticed many small EV's that use 144 volts, but some small EV's use 96/108.

If my performance requirements are modest (40 MPH/7-miles between charges) can I accomplish that with 96 volts, or must I use at least 108, and if I need 108...can a 108-volt pack be fed with a 110-120 volt generator on a Series-Hybrid trailer?

220-240 volt gens are also readily available, is this a better option (I'm electrically challenged. I tried to fix a computer with a sledgehammer once, but it just made it worse..)

Dunkard
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Re: Series hybrid... suitable generator?

What about using a brushed DC motor as a generator? Commercially available generators are usually built to run at only 3600 RPM, and so therefore are pretty heavy for their output. If you use an engine built to put out it's power at about 8000 RPM you're getting the same power in a smaller, lighter engine. Could this be coupled to a DC motor built to operate efficiently at the same speed? Then the whole package is lighter, right? But I'm wondering about how efficient DC motors are when you use them as generators.

On the issue of overall efficiency, what has been lost here so far is that the fuel efficiency of ICE's (in terms of fuel-burned per HP-produced) changes widely depending on the load condition of the engine at that moment. Gas engines are most efficient (in pounds of fuel per HP per hour) when operating at full throttle under a load that keeps the engine RPM right at the spot in the RPM range where that engine makes it's maximum torque. But when you throttle back a 200 HP car to the 30 or so HP that it takes to maintain 60 MPH, the engine will burn about twice the fuel per HP produced. This is where the efficiency of series hybrids can be better since our generator would only operate it's engine at full power, where it's more efficient, then shut off for a few minutes if the batteries are full.

Look at the Chevy Volt. There's it's electric motor with about 160HP peak for momentary tire smoking power, but will probably only use 25HP at highway speed on level ground. A 70HP gas motor drives it's generator, but will probably only run at high throttle settings, making it far more efficient than a 160HP gas engine would be if throttled back to only 25 HP. On the highway, the 70 HP gas generator will probably turn itself on-and-off every few minutes (and always at full power) as the batteries need it to. Overall the efficiency will be better than you'd have with a 160 HP gas motor throttled back to 25 HP, and then running that power through a mechanical transmission. The accomplishment: a fast accelerating car, but with a SMALL engine running much more efficiently than a similarly performing car with a large engine. Except for the fact that the hybrid could not maintain a dangerously high speed for more than a short burst. It would just have good off-the-line acceleration.

Another case in point:
All diesel-electric trains have always been series hybrids for the same reason. Only the electric motor is large enough to handle the momentary hill-climbing power needs. The batteries are only big enough to supply this amount of power for a short time. The diesel engine is only slightly larger than is needed to supply the continuous power required on level ground, plus charge the batteries a little at the same time. If trains didn't use the series-hybrid approach, the diesel engine would have to be much bigger - sized to deal with the steepest hill on the track - but back on level ground, the engine would operate throttled way back most of the time, and therefore, be less fuel efficient overall.

The lession to be learned here, is that the series approach is only best used on vehicles with momentary power demands that are MUCH larger than their normal continuous power requirement. Obviously, a 50cc scooter that usually cruises at wide open throttle is already operating as efficiently as possible, so a series hybrid with the same performance would not work out so well. BUT, if you're talking about a car that you want to have momentary high performance out of, it's a totally different story. A converted motorcycle that is meant to accelerate (and pass on the highway) like it had a 70HP+ gas engine would also be a good candidate for series hybrid conversion since such bikes still only need about 12 to 15HP to cruise at 65MPH. Ultra fast 140HP Japanese crotch rockets don't get such good gas mileage as you might expect, because they represent the most "throttled-back" engines on the road, and burn a ton of fuel per HP under their normal, "lightly loaded" highway conditions.

A high performance bike with unlimited range, and yes, a not so long electric only range, like the Chevy Volt approach, is what I'd like to build, which brings me back to my question in my first paragraph about how to build the lightest possible generator using a high RPM gas motor (from a 150cc single cylinder 8,000RPM 4 stroke motorcycle with the transmission cut off) and a high RPM DC motor putting out about 12Kw. Do DC motors make efficient generators or not? Anybody know?

goodnslo
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Re: Series hybrid... suitable generator?

Its amazing how sometimes this forum talks in circles. You have identified the majority of the areas that I stated had to be looked into for making a series hybrid to work.

DC brushed motors are not that efficient as generators and this is why the car industry moved away from them in favor of alternators. If you look at the commutator as a fixed timing device, it will not work for every RPM range as well as collapse the charging field wasting electrical energy to build back up.

The generator industry (at least in the RV/Mobile Comms market) has been gravitating to brushless DC. The generators have generally been lighter than equally matched kW gens from previous generations like the 7.5 kW gen I mentioned earlier is roughly 500-600 lbs (diesel) compared to the 800 plus previously used.

If you truly are intent on using a motorcycle engine, the higher rpm may be inhibitive to power generation unless it is severely geared down.

Dunkard
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Re: Series hybrid... suitable generator?

Hi goodnslo.

I'm so new here I didn't realize anyone had already made these points before, but it's good to finally get a comment about the efficiency of DC motors as generators. I've also learned since writing my last post, that there are some high RPM AC alternators on the market that might work well for the hybrid motorcycle I described above. Perm Motor (I think they're in Germany), the same people who make that nice little DC motor that so many people have already used to make electric motorcycles, also have a line of water cooled AC Generators (and why they call them generators instead of alternators I don't know) that are just about as small and lightweight as their DC motors are. They are made for the RPM range I'd like to use, and the part about being water cooled doesn't bother me a bit since I was going to use a water cooled gas engine and have a radiator anyway. But now I'm wondering how much power gets wasted when you rectify the AC into DC ? I'd need some big freakin' diodes I guess. I know it would eliminate a lot of RF noise if I get away from the brushed DC motor idea for my generator, so I'm all in favor of that. Efficiency is my main concern since the overall size and weight of the vehicle is so small when you're doing a motorcycle.

schnelsr
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Re: Series hybrid... suitable generator?

I've been looking for a range extender for my ebike. Series hybrid or as a charger for one battery as I use another. The Honda or Yamaha generator in my Nashbar cargo trailer is what I have been considering. The Yamaha is substantially quieter and has better fuel economy at low outputs although I would expect to run it pretty much flat out. It uses an inverter rather than diodes, apparently for better efficiency.

The Perm Motor might be the thing, though. Mated to a modified weed wacker motor it looks like a good match 1.3 KW output at 87% efficiency. I assume the "generator" means DC output which would remove the inverter.

As to the effeciency question: What's more efficient moving one person 180 miles (my goal so I can get to the lake house), a 2500 pound ICE Honda car getting 32 MPG or a 100 pound ebike getting 1000 MPG (figuring the Yamaha generator backing up a pair of 48 VDC 20AH LiFePO4 batteries)

Here's the link to Perm Motor (some of it is translated but some german helps):
http://www.perm-motor.de/site/en/products/syn_generators.php?linkid=p&linkid2=3
They look like the ticket.

Anderson
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Re: Series hybrid... suitable generator?

My disclaimer; Please note the following is for purposes of discussion only and is not intended to be used as final plans that can be used to be made into something.

Here’s a series hybrid generator plan for a Vectrix scooter but would generally work on electric vehicles particularly where you want to put a proportionately small generator on an electric vehicle. I’m not necessarily going to try this myself but am interested in what you think of the basic concept

My idea is to use a light weight AC inverter generator like the 850 watt 27LBS “ETQ 800I” usually sold on E-bay. I picked this not because I have any experience with it but because it is the lightest weight one I could find.
It would be mounted in the passenger’s seat area and its AC output goes to a custom wound step-up transformer that’d supply enough voltage to charge the Vectrix’s 140 volt NiMH battery after going through a rectifier. A programmable Controller would turn on and off the AC with relays to maintain the battery's SOC at 65% but not above that.
Because the inverter generator’s voltage output is fixed and doesn’t increase as charging progresses the transformer would have 2 or 3 taps in its secondary winding at maybe 4 volts apart (like 150, 146, 142, 138 volts), see the picture so when the batteries SOC was high the Controller would select a higher voltage output tap for a higher charging voltage. Alternately there’d be an AC current sensor for the generator’s AC output monitored by the Controller so that if the generator’s output was over its continuous duty amperage rating the controller would select the next lower voltage tap to reduce the charging voltage.

Note when the Controller switches to another tap the tap that was on would momentarily stay on in order to maintain an uninterrupted power output.
Serial_Hybrid-.png

caspar21
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Re: Series hybrid... suitable generator?

am i on the right track here?
1998 Pontiac Sunfire.
est 15 hp used to maintain 60 mph.(wild guess, could use better info)
7250W generator (6500W usable continuous)
1 watt = 0.00134102209 hp.
0.00134102209 * 6500W = 8.7166 hp produced.
8.7166 / 15 = 58.11 so:58.11% of the power needed will be provided by the generator,
so i can expect the range to be increased over just battery by 58.11%
40 mile range on battery alone.
40 * 1.5811 = 63.244 Miles range with generator running(before stopping to allow it to charge up again)

I just realized something: we have anti idling laws here in Canada. i cannot leave the genset charging when i am in a restaurant or i will get a fine.

michaelross
michaelross's picture
Offline
Joined: 09/07/2009
Points: 6
Re: Series hybrid... suitable generator?

dwangyahoo wrote:

It seems no one is putting on a generator to extend range at this forum.
Finally, after lots of googling, I found a Canadian who used a 5kw induction motor as an induction generator and put it at the back of his S10.
It's in French:
http://www.vehiculevert.org/levehiculevert/index.php?lien=chevrolet

When I post the translated link, it doesn't work. So you can googe "Véhicule Vert", then click on the "translate this page" link.

I am really interested on this. I also have a chevy s10 that's why i am looking s10 parts like motors or a generator for it. And I checked out the site. It really is french and the translate this page menu does not work at all. Oh well.

antiscab
Offline
Joined: 07/07/2007
Points: 1598
Re: Series hybrid... suitable generator?

if you are going to use a genset,
make sure your charger is either PF corrected (otherwise your "7.25kw" genset will be only good for ~3kw) or can be hacked.

by hacked, i mean bridging the DC bus of your charger with the DC bus of your genset (get an inverter model).

better still, go parrallel hybrid.
petrol -> mechanical ->mechanical is more efficient than:
petrol -> mechanical -> electrical -> electrical -> electrical -> electrical -> mechanical -> mechanical
(output from alt) (DC bus) (charger output) (controller output) (motor output) (transmission)

you lose something in every conversion.....

Matt

__________________

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah
Vectrix 60Ah Lithium Tyres Fuel Registration Insurance cycle analyst replacement TC Charger
conversion
Spent so far: $5800 + $7000 + $1720 + $960 + $320 + $720 + $140 + $600
Cost to do it again: $2500 + $5600 + $1720 + $960 + $320 + $720 + $140 + $600
Cost for a Petrol bike:$6000 + + $1440 + $6000 + $800 + $1400 + $3200 servicing
Total spent: $17260
Total to do again: $12560
Total to have used a petrol bike: $18840
Total distance travelled so far: 79'120km

marylandbob
Offline
Joined: 06/22/2009
Points: 520
Re: Series hybrid... suitable generator?

Even a vehicle such as the VECTRIX scooter has power demands far beyond a simple, lightweight generator! My vectrix will travel about 30 miles on a charge, at 60 miles per hour. Based on its 125 volt, 30 AH battery, this indicates that over 3 KWH are needed for this 1/2 hour trip, or a 6,000 watt generator would be needed to "Break Even" Most generators of this capacity are far too big and heavy to install on a scooter! Perhaps a small TURBINE powered alternator could be made light enough, but present COST is very high for small turbines. A smaller generator, in the 3,000 watt range, could give a useful range extension.--Just do a little thinking-Vectrix battery takes about 3 hours to fully charge from 1.5 kilowatt mains supply, but can be depleted in 1/2 hour of 60 mph travel--That works out to 4.5 KWH used to charge, and it all gets used in 1/2 hour, so at that conversion efficiency, a 9,000 watt generator would be needed!-If you find a generator set that weighs less than 100 pounds, and can provide a reliable 6,000 watts from a small size package, running efficently on cheap, readily available fuel, for $500.00 or less, let me know!(Best efficiency would be obtained by bypassing the charger, and directly feeding generated D.C. to the battery/motor )-------Bob Curry

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Robert M. Curry

antiscab
Offline
Joined: 07/07/2007
Points: 1598
Re: Series hybrid... suitable generator?

even coupling the DC buses will probably be less efficient:

petrol --> mechanical -> electrical -> electrical -> electrical -> mechanical
(alternator output) (PFC output to DC bus) (controller output) (motor output)

using a genset maybe viable if you just need to extent range once in a while, rather than to just drive forever between charges (as with any other hybrid).

Matt

__________________

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah
Vectrix 60Ah Lithium Tyres Fuel Registration Insurance cycle analyst replacement TC Charger
conversion
Spent so far: $5800 + $7000 + $1720 + $960 + $320 + $720 + $140 + $600
Cost to do it again: $2500 + $5600 + $1720 + $960 + $320 + $720 + $140 + $600
Cost for a Petrol bike:$6000 + + $1440 + $6000 + $800 + $1400 + $3200 servicing
Total spent: $17260
Total to do again: $12560
Total to have used a petrol bike: $18840
Total distance travelled so far: 79'120km

marylandbob
Offline
Joined: 06/22/2009
Points: 520
Re: Series hybrid... suitable generator?(Advantage/Efficiency?)

An electrically driven series hybrid CAN be more efficient than directly driving the vehicle with the internal combustion engine or fuel cell! Why and HOW? Remember this: for a given level of vehicle performance, the horsepower needs vary GREATLY between the power required to rapidly accelerate from one speed to another, the power to climb a long, steep hill, and the power to sustain a "Cruising speed" on level ground. The "PEAK" power capability of an internal combustion engine (or fuel cell) normally is less than 25% more than its continuous power, and as result, an engine of much larger size than required for level ground "Cruising" is needed. Typically, this means the engine is physically larger and heavier, and must often operate at engine speeds and power output settings that are not optimum. Inasmuch as a typical ELECTRIC motor can often provide output power that exceeds its continuous rating for 5 minutes or more, with PEAK power often 400% greater than rated power, and most such ELECTRIC motors are very efficient over a very WIDE power and RPM range, whic often enables operation WITHOUT the use of a heavy, power consuming, TRANSMISSION and/or CLUTCH! This often enables use of a 50 horsepower electric motor, to replace a 200 horsepower internal combustion motor and transmission, with no loss in performance! To obtain this performance, the internal combustion engine that drives the alternator/generator is typically 1/2 the size, or less, as otherwise required, and the additional needed power comes from the battery bank during rapid acceleration and hillclimbing. Because of this, the engine driven alternator/generator must be large enough to supply output that EXCEEDS the "Cruising" power required by the vehicle, and the excess is used to keep the battery charged and ready. This system also permits the internal combustion engine to be operated at its OPTIMUM speed/power setting, and therefore operate more efficiently. (an added benefit is that it is not required to keep the engine running at traffic lights, as the electric motor responds almost instantly, thereby avoiding sitting at a light, with a running engine, getting ZERO miles per gallon!) If electrical demands have diminished the battery charge, the internal combustion engine may operate while stopped, but its energy would be USED in recharging the battery.That is MY outlook on the "Series Hybrid" situation.--Bob Curry

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Robert M. Curry

Dauntless
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Joined: 05/27/2010
Points: 220
Re: Series hybrid... suitable generator?(Advantage/Efficiency?)

http://rqriley.com/t-car.html

This thing from the 70's says it's running a 6,000 watt motor and charging with a 2,500 watt generator and taking 60 miles worth of 1970's batteries and extending the range to 100 miles. In a 2,500 pound car. Hmmmmm.

If you had something iight enough to make that drivetrain work, continuously charging those batteries while you're using them just HAS to destroy them. One good reason the system never caught on.

I'm just saying this is a pipe dream. I've never heard of anyone actually driving around in one of these, satisfied. I've seen people in forums saying they're having trouble getting theirs to work, but never anyone saying "Hey, it's finished, and it's GREAT!"

Well, if you MUST try putting some $9,000 or so of LiFePO4 batteries in there, do get a charger that knows how to smart charge them while they're in use. (Giggling)

By the way, a hydrogen car is a series hybrid.

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WHo dares, WINS!!!!

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