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maaca
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Joined: 21/11/2006
Location: New Zealand
Posts: 22

Posted: 07:20am 10 Jan 2007

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Hi Guys,Can any-one tell me if they know the costs of the Star Delta controller from design specialties?.I have mailed Robert twice but get no reply.Web site is.

http://www.dsgnspec.com/
Thanks Maaca.

Pt w/field Matt

Senior Member

Joined: 24/02/2006
Location: Australia
Posts: 105

Posted: 10:46am 10 Jan 2007

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hi make it at of a frequency switch jaycar kc5378 $36 and use a car or bike magnetic pulser coil and a car 12v ingniter for the tacho drive output.to pusle the pulser coil use screw heads etc3 for 6 cyl 4 for 8 cyl check it on the j/car web site and it doesnt use a special programmed chip

matt down south

mrpackethead

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Joined: 11/11/2006
Location: New Zealand
Posts: 17

Posted: 10:05am 11 Jan 2007

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Sorry don't know about the controller, but i did ecoinnovation are selling somethign for about NZ$300 I think.

I've incorporated mine into my MPPT controller, using a PICAXE-08. All solid state.. I'll put up a circuit and some code one day.

Every thing should be as simple as possible. Not simpler.

domwild
Guru

Joined: 16/12/2005
Location: Australia
Posts: 873

Posted: 07:51am 13 Jan 2007

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mrpackethead,

Great! Hope to see your idea for the MPPT soon. I intend to use Glenn's circuit with a small change, namely using an Allegro Hall effect sensor for the Amps. The MPPT is still beating what the circuit should look like. I take the circuit is driven by the PWM output of the Picaxe. Once the batteries are full, the Picaxe can then switch on the dump load.

For a star/delta controller alone I would look at commanda's frequency-to-voltage LM2917 (?) solution. Once the RPM go up, switch over using a 3pole 2 throw switch to delta. Allow a gap in RPM for hysteresis so it does not switch constantly. Go to the otherpower forum for commanda - she has a black belt in electrickery. That same chip is also in the Jaycar kit anyway.

Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up.

Winston Churchill

Pt w/field Matt

Senior Member

Joined: 24/02/2006
Location: Australia
Posts: 105

Posted: 11:26am 13 Jan 2007

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hi domwild how do you get on otherpowers site it is down for upgrading?

matt down south

mrpackethead

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Joined: 11/11/2006
Location: New Zealand
Posts: 17

Posted: 10:03am 14 Jan 2007

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[quote]
For a star/delta controller alone I would look at commanda's frequency-to-voltage LM2917 (?) solution. Once the RPM go up, switch over using a 3pole 2 throw switch to delta. Allow a gap in RPM for hysteresis so it does not switch constantly. Go to the otherpower forum for commanda - she has a black belt in electrickery. That same chip is also in the Jaycar kit anyway.

I'm working on a High Voltage F&P variant project. I'll probably be switching using some 600V triacs, and zero-crossing optoisolators. But it should work for the lower voltage projects..

Give me a week or so, and i'll post a circuit and possibly a pcb if you are lucky.

Every thing should be as simple as possible. Not simpler.

domwild
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Joined: 16/12/2005
Location: Australia
Posts: 873

Posted: 01:35am 15 Jan 2007

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Matt,

I meant Fieldlines, just been on there, they do not seem to be upgrading. Aren't they one and the same board? Sorry, it is Fieldlines.

mrpackethead,

Schematic hand-drawn sketch is OK, if you have the time - who has??

I have a suspicion your scheme will perform some step-wise switching in and out of 100W loads or similar. I have seen something like that on Fieldlines. I was thinking more along the lines of varying the PWM along the lines of and similar to pulse charging (desulphating) a battery as per the desulphator forum. More power from the mill means a longer pulse, etc.

If my suspicion is right, then your scheme works a bit along the lines of Hugh's AC switching in his dump load controller - am I right or are you wrong??

Keep us posted!

Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up.

Winston Churchill

RossW
Guru

Joined: 25/02/2006
Location: Australia
Posts: 495

Posted: 02:41am 15 Jan 2007

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Andrew and I have spoken about this off and on for some time in irc (irc.albury.net #aussiere) and as I understand his current plans, is to generate power at a reasonably high voltage (exact volts unimportant) and run that into in effect, a switchmode supply.

The switchmode supply, by using PWM in the "inverter" stage can maintain an output voltage that will ensure a required current (thus, "wattage output") that is optimum for a given wind speed.

As the wind speed varies, we can "force" the turbine speed to increase or decrease by changing the load on the output.

While I don't think this has been done just yet by any "DIY" type folk, I understand this is pretty close to the technology being incorporated into some of the latest 1-10KW sized commercial mills.

I'm pretty sure that for any given wind speed, there will be a point of equilibrium where further load will reduce the speed of the mill (thus reducing output power, and ultimately requiring reduction of output current, allowing the mill to speed back up). Alternatively, to increase speed would require reducing power out (then the mill will create more power at higher RPM and require the PWM to increase load, slowing the blades again). This equilibrium point should be a single point on a curve, for any given wind velocity. Using feedback in the MPPT controller should allow it to settle on this point, or a simple wind-speed input should allow the controller to determine the optimum point and get there quickly for any given turbine characteristic. (Perhaps the controller could "learn" your turbine over time).

RossW

mrpackethead

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Joined: 11/11/2006
Location: New Zealand
Posts: 17

Posted: 03:48am 15 Jan 2007

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It time that i put all my stuff up on a web page. At the moment its all pretty much just a pile of bits, but its coming together.. However for the time being..

(1) Yes, i am intending to run my mill at high(er) voltage. I'm expecting to see between 90 and about 350VAC, which i will rectify to DC. This is using an unmodifyed F&P stator.    Running at higher voltage, has the benefit of reducting the current, which helps lots of things.

I suspect *yet to be confirmed* that i will get a better energy conversion with the higher voltage configuration, particulary at low voltage.

(2) The Switchmode supply essentially will match the energy output of the mill, to the load, using a couple of techniques, including PWM, and controlling the current. The output will be a constant voltage however.

(3). Less the load presented to the mill, will force a change in speed.. Too little load, and it will overspeed, too much load, it will stall.

(4) Yes, the technology is being used in small (>10kw) and larger (~100kW) systems. I hav'nt as yet found a DIY project yet either.. lots of people who have done 'parts' of the system though..

(5) Yes, there is an equilibrium point.   Intialy i had thought of 'learning' a curve for a given mill.. A bad idea, as there are lots of variables to account for. So, i'll be using real time dithering, of the load presented to the mill.. In effect the system will be contiously adjusting it self to maximise efficency..   I need to draw soem pics to explain.. The good point about this, is that the system will work for any generator, without telling it about any characteristics.

Ultimately the controller will be a MPPT ( maximum power point tracker ), a battery charger controller, with dump load, and a star/delta switch..   I'll also be runnign a data logger in it, and i'm sorely tempted to add an IP stack, so its remotely viewable and managable.

Maybe it will be finished by christmas :-) Unforutnatly real paying projects are in the way ( aka work )

Every thing should be as simple as possible. Not simpler.

domwild
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Joined: 16/12/2005
Location: Australia
Posts: 873

Posted: 09:21am 15 Jan 2007

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Friends,

Have seen a student project (American Engineers Abroad or similar) for MPPT + mill but no Picaxe or F&P AND only 11% efficiency! If anyone is interested, then I will dig it up.

Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up.

Winston Churchill

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