- I am new to this forum. Hello to all. I am preparing to install a small off-grid hydropower system in Chile. I have head and flow for about 2kw; however, theMessage 1 of 66 , Jan 1, 2008View SourceI am new to this forum. Hello to all.
I am preparing to install a small off-grid hydropower system in Chile. I have head and
flow for about 2kw; however, the location of the turbine is a 300 feet from where the
power is needed. I have a choice between 1) a DC turbine with a lot of line loss (or inch
thick wire) or 2) An AC turbine.
An AC turbine solves the transmission problem; however, it creates other problems as the
invertor/chargers are not designed for AC systems.
Anybody out there know the best way to use an AC turbine with a battery bank and
- Okee dokee....I get all of this...except the last part with the ballast load on the hydro before the first controller...how does that work? (If you¹ve alreadyMessage 66 of 66 , Jan 17, 2008View SourceOkee dokee....I get all of this...except the last part with the ballast load
on the hydro before the first controller...how does that work? (If you¹ve
already discarded that idea...or it¹s not a likely one on your list, don¹t
worry or waste your time...)
On 1/8/08 11:51 AM, "nando" <nando37@...> wrote:
> After so many suggestion that have come along for Jeffe to implement in his
> hydro I am making public what I said to him via direct mail.
> I know Jeffe for years and I know his system well until recently when the
> latest technical people made an electrical mess that has two power source
> (solar panel and hydro) with several ( more than two) charge controllers that
> are not synchronized or regulated between themselves.
> Jeffe problem has two solutions for a cleaner wiring and good battery
> The over charge of the battery can be solved in an easier way , since the
> system has a Pure sine wave inverter ON all the time, the system can use this
> power source to control the battery voltage by detecting the battery voltage
> and triggering a TRIAC or SSR to turn a water heater resistance with a power
> about 30 to 40 % higher power than the generated power and in addition a
> secondary loop when the water heater over temperature thermostat opens the
> load to re-route the power to other ballast load -- this way all the excess
> power to heat water for home use ( I have done something like that to heat a 5
> cubic meter tank for shower and / or home ambient heating).
> The ideal case would be a PWM TRIAC controller to have the battery at fixed
> maximum voltage level with no battery peak fluctuations.
> The other solution is to have a ballast load on the hydro before the hydro
> charge controller to maintain a high safe voltage, this way the ballast does
> not load the battery bank and 2 charge controllers ( mppt type ) do not
> overcharge the battery bank, a simpler MosFet ballast controller.
> He has other issues that need resolution for proper system health which we are
> taking care of.
> ----- Original Message -----
> From: k1hop
> To: email@example.com <mailto:microhydro%40yahoogroups.com>
> Sent: Tuesday, January 08, 2008 8:08 AM
> Subject: [microhydro] Re: AC Turbine with battery bank
> Hi... thought I'd jump in here with a suggestion... though perhaps
> you've already considered it. Would seem quite simple to rig up a
> precise voltage sensing circuit that turns on a MOSFET (or other)
> transistor across the panel/hydro output (to ground). This would act
> as a "shunt regulator" and continuously dump excess energy to ground.
> It would maintain whatever precise voltage output you set, no relays
> to wear out, no clunking noises, no hysteresis, etc. It is a LINEAR
> regulator (with very high gain) not a "bang-bang" digital type like
> your relay, so hysteresis is not needed. The more the voltage rises
> above the set-point, the harder the transistor turns on to shunt it
> back down. If the voltage drops below the set-point, the transistor
> is not turned on at all, and on dumping occurs.
> While you're talking a bit of power, there are many BIG, powerful, yet
> inexpensive transistors around these days. With a good size heatsink
> and perhaps a fan to help out, it could readily dissipate the excess
> power. And, since it is constantly functioning, there is no big
> buildup of excess power needing to be suddenly dumped... it's more
> gradual, continual, and thus easier on the whole system.
> Hope you find this useful.
> --- In firstname.lastname@example.org <mailto:microhydro%40yahoogroups.com> ,
> Jeffe & Carrie Aronson <jeffe@...>
>> > Hi, Dave. Thanks for your input (pun intended):
>> > Actually, I¹ve tried various hysteresis settings, large and small
> (.4 to 2).
>> > Problem is (I THINK!)...that when the sun is shining, the panels are
>> > producing as much as 16 amps (at 24v = 380 watts), plus the hydro
> going at
>> > about as much. With my wonky system the installers went with 2
>> > one for the solar, one for the hydro, and they¹re not synchronized. The
>> > panel one reads battery voltage as up to .5v less than the hydro one.
>> > Consequently, the panels keep charging for a small amount of time
> after the
>> > dump relay is turned on by the hydro, jamming in excess of 700 watts
> into a
>> > 400 watt dump load. I¹ll be changing this system soon, however, in any
>> > case...if you¹re input is high, even with one controller with a high
>> > hysteresis, with no or small household loads during the day and
>> > input from the sun, you very well might be jumping a relay rapidly
>> > Mine (with the unsynched controllers and during a sunny day) goes
> from 29.4v
>> > (battery state of charge) to 27 in a matter of a second or two, then
>> > rapidly back to its high within 15 or 20 seconds. That¹s with a 2v
>> > hysteresis. That¹s a lot. Thus, it seems that even with no solar,
> you could
>> > see a cycling of the relay in 30 to 40 seconds. No?
>> > Jeffe
>> > On 1/7/08 11:39 AM, "dave_festing" <dave_festing@...> wrote:
>>> > >
>>> > >
>>> > >
>>> > >
>>> > > Sounds like you haven't got any hysteresis on what ever is controlling
>>> > > the relay.
>>> > >
>>> > > For example, relay closes when the voltage is 15.0 Volts and the relay
>>> > > opens at 14.0 Volts. You should be able to find a point where the
>>> > > relay cycling period is lower without "wasting" too much of the
>>> > > stored power in the batteries.
>>> > >
>>>>> > >> > I have a relay and solenoid to fire the ³dump², or resistive load
>>> > > instead of
>>>>> > >> > through the internal load of the controller...and when the power
>>> > > input is
>>>>> > >> > high, the relay clunks on and off repeatedly, dumping, then
> letting the
>>>>> > >> > batteries reaload, etc. when we¹re not using large household
>>> > > Consider
>>>>> > >> > the noise, but also consider that relays are mechanical, and
> they will
>>>>> > >> > probably eventually fail. You should have a backup so that if
> the relay
>>>>> > >> > fails open or closed, you do not harm the batteries or
> overspeed the
>>>>> > >> > turbine....just a thought.
>>>>> > >> >
>>>>> > >> > Jeffe
>>> > >
>>> > >
>>> > >
>> > [Non-text portions of this message have been removed]
> [Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]