Alternative Power sources - Hybrid Generator Concept for Improved Generator Efficiency

Author

Hybrid Generator Concept for Improved Generator Efficiency

Plan B

2005-10-16, 8:21 pm

I think efficiency could be improved with a "hybrid" system that
uses an engine and a battery, similar to the systems used in cars like
the Toyota Prius or Honda Insight.

The design idea I was thinking of was to use a generator together with
an interactive type UPS (Uninterruptible Power
Supply)http://en.wikipedia.org/wiki/Uninte...e_power_supply.
Suppose you selected a generator that was slightly small for the
application, such that the peak power output could not supply enough
power to drive a peak load directly. Then during a time of peak
loading, the generator output voltage would sag. In this case, the UPS
would draw supplemental power from the batteries to meet the peak load.

In this system, the engine losses are reduced. During periods of low
power demand, idle engine time is instead used to charge batteries.
The hybrid system is more efficient because you've removed the large
engine, and you're not trying to run the engine at low r.p.m. "A
modern Otto cycle engine tends to be most efficient at 40% to 45% of
its "red-line" r.p.m. and 70% to 80% of its peak torque."
http://home.earthlink.net/~graham1/...lCombustion.htm
The larger engine also has more friction, so power is required just to
keep the engine running. Most engines aren't equipped with technology
to run efficiently at low speeds, for example technology like cylinder
disabling or Honda VTEC. http://auto.howstuffworks.com/question229.htm
Using a large engine is not the only way to meet the peak-power
demands.

Another way to improve efficiency is with load balancing. Most
generators aren't sized to run everything in a house anyway, so the the
load balancing is often done manually at the switch box. A more
sophisticated control system could take in to account scheduling needs,
and wait until the power demand is reduced before switching on
appliances like a refrigerator or a water pump.

danny burstein

2005-10-16, 8:21 pm

In <1129501816.749070.113050@o13g2000cwo.googlegroups.com> "Plan B" <mphillipps2@yahoo.com> writes:

>I think efficiency could be improved with a "hybrid" system that
>uses an engine and a battery, similar to the systems used in cars like
>the Toyota Prius or Honda Insight.

>The design idea I was thinking of was to use a generator together with
>an interactive type UPS (Uninterruptible Power
>Supply)http://en.wikipedia.org/wiki/Uninte...e_power_supply.
>Suppose you selected a generator that was slightly small for the
>application, such that the peak power output could not supply enough
>power to drive a peak load directly. Then during a time of peak
>loading, the generator output voltage would sag. In this case, the UPS
>would draw supplemental power from the batteries to meet the peak load.

That is, in fact, readily available "off the shelf"
with a bunch of the Yamaha portable inverter generators.

(And is the key reason I'm considering one of
them over the similar inverter, but no "assist", Hondas)

" Ever need a little boost ...extra power that gets your tool or
air conditioner started quickly and efficiently? Now you can get
that "boost" thanks to the EF3000iSEB generator's Yamaha
Boost Technology (YBT), which boosts output by adding battery
voltage to alternator when needed.

typical descriptive url:

http://www.northerntool.com/webapp/...665&R=200315665

--
_____________________________________________________
Knowledge may be power, but communications is the key
dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]

RoughRider

2005-10-17, 2:21 am

The hybrid car (and even hybrid railway switch yard locomotives) are great
for stop and go applications where large amounts of power are required to
get moving, then power requirements taper off. Hybrid cars are excellent
for city, but limited by the engine horsepower at highway speeds. They
depend on slowing down or idling to be able to charge the battery. Depends
how small the engine is and how the manufacturer tipped the balance towards
battery assist.

But for home power, you have motor loads like refrigerators that draw surge
currents for under a second. Otherwise many devices consume a relatively
constant amount of power, so you really don't have much efficiency to gain
by undersizing the inverter or the generator that feeds it.

There is another way... it is called "cycle charge" where you oversize the
battery (huge) and run the engine every so often at or near its most
efficient operating point. You can tweak the controller values to find the
optimal battery/generator duty cycle. Typically you let the batteries
dischage to 80% capacity or so and then start the generator to get the
battery back up to 95%. The generator will never idle. You would use wind
or PV to try and get the battery up to 100%.

Regards,

RF Dude

danny burstein

2005-10-17, 6:21 am

In <fMF4f.6839$ns3.259927@news20.bellglobal.com> "RoughRider" <Reply@ThisNewsGroup.com> writes:

>The hybrid car (and even hybrid railway switch yard locomotives) are great
>for stop and go applications where large amounts of power are required to
>get moving, then power requirements taper off. Hybrid cars are excellent
>for city, but limited by the engine horsepower at highway speeds.

Those of us driving the hybrids (such as the Honda Insight)
have no trouble whatsoever keeping up with highway
traffic speeds.

(can't speak for all the different models out there, of course).

--
_____________________________________________________
Knowledge may be power, but communications is the key
dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]

Vaughn

2005-10-17, 7:21 am

"danny burstein" <dannyb@panix.com> wrote in message
news:divpd9$ltc$1@reader2.panix.com...
> In <fMF4f.6839$ns3.259927@news20.bellglobal.com> "RoughRider"
> <Reply@ThisNewsGroup.com> writes:
>
>
> Those of us driving the hybrids (such as the Honda Insight)
> have no trouble whatsoever keeping up with highway
> traffic speeds.

In your rush to defend hybrids at all costs, (even though he never said
that hybrids can't maintain highway speeds) you seem to have missed RF Dude's
main point. It is a shame because it was a good one.

Vaughn

danny burstein

2005-10-17, 8:21 am

In <5MK4f.447761$5N3.94544@bgtnsc05-news.ops.worldnet.att.net> "Vaughn" <vaughnsimonHATESSPAM@att.fake.net> writes:

[color=darkred]
> In your rush to defend hybrids at all costs, (even though he never said
>that hybrids can't maintain highway speeds) you seem to have missed RF Dude's
>main point. It is a shame because it was a good one.

Looks like I missed it. I can tell you flat out
that Insight (and most others.. can't swear
to all) hybrid cars are _not_ "limited by
the engine horsepower at highway speeds" - at least
any more than any other car is similarly limited.

Can I do 150 mph? No. But very few other
cars can either.

Can I maintain standard (not necessarily
speed limit...) speeds and even
pass as necessary? Absolutely.

The deal with hybrids (oversimplified a bit here...)
is that "regular" cars have engines that
are way, way, larger than needed for cruising
highway use. This gives you plenty of extra
horsepower when pulling onto the highway, but
otherwise wastes plenty of fuel.

The hybrids have engines that are more than
adequate for highway cruising (that is, smaller
than regular cars but still quite good)
and get extra acceleration horspower (for
that "on ramp") courtesy of the battery
pack and integrated electri motor assist.

Presumably if you're on a long mountain upgrade
where that extra 25 horsepower might be needed
for a half hour... you'll have some issues
with the smaller hybrid gasoline engine, but
that's a pretty rare situation.

--
_____________________________________________________
Knowledge may be power, but communications is the key
dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]

RAO WHITEPAPER TEAM

2005-10-17, 9:21 am

"Plan B" <mphillipps2@yahoo.com> wrote in message
news:1129501816.749070.113050@o13g2000cwo.googlegroups.com...
> I think efficiency could be improved with a "hybrid" system that
> uses an engine and a battery, similar to the systems used in cars like
> the Toyota Prius or Honda Insight.
>
> The design idea I was thinking of was to use a generator together with
> an interactive type UPS (Uninterruptible Power
> Supply)http://en.wikipedia.org/wiki/Uninte...e_power_supply.
> Suppose you selected a generator that was slightly small for the
> application, such that the peak power output could not supply enough
> power to drive a peak load directly. Then during a time of peak
> loading, the generator output voltage would sag. In this case, the UPS
> would draw supplemental power from the batteries to meet the peak load.
>
This is plug-and-play with the Xantrex SW+ series of inverters.

barry@sme-online.com

2005-10-17, 3:21 pm

You missed this:
"They depend on slowing down or idling to be able to charge the
battery."

Especially the regenerative braking part. Kinda hard to get that from
powering house.

Relax,
J

danny burstein

2005-10-17, 7:21 pm

In <1129571283.763215.248950@g44g2000cwa.googlegroups.com> barry@sme-online.com writes:

>You missed this:
>"They depend on slowing down or idling to be able to charge the
>battery."

err, kind of. but ... see below

>Especially the regenerative braking part. Kinda hard to get that from
>powering house.

The IMA "motor" in the Hondas (don't know for sure
about the Toyota Synergy setup) is also a generator.

It can, and does, generate electricity (for charging
the battery) during "normal" driving, as opposed
to only while slowing down.

And yes, we all know about the Second Law. That
electricity does, in the long run, come from
the burning gasoline. But there's very little
effect on motoring performance - the pickoff
(retardation equivalent) is a fraction of
a horspepower - and that generation only takes
place when
a) needed
and
b) if there's motor power to spare.

In other words, it might activate when
you're doing 75 on the highway, but won't
when you're doing 95...

--
_____________________________________________________
Knowledge may be power, but communications is the key
dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]

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