On 2 Dec 2018 at 11:21, AB Pearce - UKRI STFC wrote:

> > I'm thinking a shunt regulator is the way to go with a wind
> turbine. Set at a voltage above what the solar PV produces
> > (30.8V @ Vmp), but safely below Vmax allowed for inverter (45V
> operating, 55V Abs max), capable of dissipating 300W
> > or so worst case. Could dump power into a power resistor or
> incandescent lamp or heater element, with say a PIC
> > PWM'ing a MOSFET. Or even use multiple power MOSFET's in linear
> mode... the heat has to go somewhere and could
> > possibly work out cheaper by not requiring expensive power
> resistor(s). Perhaps a fan on the heatsink kicking in as required.
>=20
> Huh? If the wind is blowing to the extent that you are having to
> waste energy won't the wind itself be enough 'blow' across the heat
> sink, especially if using one with long fine fins that have a lot of
> surface area? Especially with the Southerlies you are likely to get
> (or are you in a very sheltered spot.

Thanks Alan, I'm in Hamilton, most weather comes from the West. Probably on=
e of=20
the highest houses in town but that's not saying much, still difficult to g=
et turbine up=20
high enough into direct wind.
=20
https://www.wunderground.com/personal-weather-station/dashboard?ID=3DIWAIKA=
T
O20

Was planning to put the electronics out of the weather, under a balcony, so=
 wind=20
might help cool a little but fan forced I could make everything smaller.

> For a shunt regulator I suspect that a 2N3055 type jelly bean power
> transistor with a bit of smarts driving its base through a zener
> diode to set the shunt voltage will be about what you need. May
> require several transistors, and may want a resistor in each
> collector to limit the maximum current draw in event of
> semiconductor failure, or prevent such failure, and even out the
> dissipation between transistors.

Yip, I want to keep it fairly simple. By 2N3055 you mean the good old TO-3 =
steel=20
package? Can still get them apprently.
=20
> > The wind turbine is rated at 300W, 24VAC 3ph. With a 3-ph bridge
> rectifier plus filter capacitor I'm expecting
> > in the order of (24 x 1.41) - (2 x 1V) =3D 32VDC, current around
> 300W/32V =3D 9.4A.
>=20
> I would be tempted to use Tungsten car headlamps as the load
> controlled by transistors as detailed above. However you would need
> truck ones for 24V, so I suspect aluminium bodied resistors mounted
> on heat sinks will be the way to go - you can select your load
> resistance more easily and accurately, and the resistors are
> available at reasonable price in wattage ratings that will allow you
> to run them well below rating.

Cool. I make potentially add a series regulator as well with decent high vo=
ltage=20
transistor, to protect the shunt regulator... if I have say a 200km/hr wind=
 event, and=20
the wind turbine doesn't deploy its "face away" tricks then volts and amps =
might get=20
out of hand, I'd rather the generator fry than the regulator and then inver=
ter.



--=20
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