> 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... t=
he heat has to go somewhere and could
> possibly work out cheaper by not requiring expensive power resistor(s). P=
erhaps a fan on the heatsink kicking in as required.

Huh? If the wind is blowing to the extent that you are having to waste ener=
gy 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? Especiall=
y with the Southerlies you are likely to get (or are you in a very sheltere=
d spot.

For a shunt regulator I suspect that a 2N3055 type jelly bean power transis=
tor 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 dra=
w in event of semiconductor failure, or prevent such failure, and even out =
the dissipation between transistors.

> The wind turbine is rated at 300W, 24VAC 3ph. With a 3-ph bridge rectifie=
r 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.

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, s=
o I suspect aluminium bodied resistors mounted on heat sinks will be the wa=
y to go - you can select your load resistance more easily and accurately, a=
nd the resistors are available at reasonable price in wattage ratings that =
will allow you to run them well below rating.



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