At last we've had enough wind today to do a bit more testing. Very convenient as I've just finished the charge/dump controller and was able to leave the system buzzing away to itself while I got on with a few other things.
I'm still limited to a pair of 150amp/hr truck batteries so I can't handle the full current of the final system (certain not on discharge, which runs over 40amps, anyway) so I ran a 500w halogen heater on the inverter as a 'dummy load' - a reasonable 25amp load. The inverter was switched by the controller so that it cut in at 28v and dropped out at 22v. With a charge rate varying from 5 to 30 amps the load was cutting in for a few minutes every half hour or so. The rapid cycling is of course due to the relatively high impedance of the battery string so that when I hit it with 20amps of charge current, the volts the controller sees goes over the 28v trigger point and the load is turned on. I'm sure everything will be fine when I've got 5-600 amp/hrs hanging onto it so the power is soaked up better.
I even had enough wind (gusting to about 30km/hr) to see the furling start when I was loaded up to 30amps (around 800 watts) - the whole system seems to perform much smoother with some grease on the yaw bearing and furling hinge!!
Still very quiet - its about 50m from the house and even my wife's acute hearing couldn't hear it above the sound of the breeze through the trees in the garden. At 11m high its still a bit low but until I've more batteries and the permanent mast its not worth cranking the telescoping trailer mast up to the length of the cables (about 16m) as I'd have to mess about with another set of guys if I run up another section. The permanent mast will also be a bit further from the house so that will cut down turbulence when the wind is blowing from the NE as it was today.
This weeks task is the swimming pool pump controller and to edit up a video of my pride and joy...
