Electronics setup for wind turbine - Page 1
Forum section: electronics / projects

author: fish654321789
author_rank: Newbie
timestamp: December 19, 2023, 05:09:23 am
content: Hello, I have a wind turbine project but I have a problem.I will use a 24v AC generator rated at around 5kw max output.I want to use the electricity in my home or put it back into the grid and for that i need 220/230v AC power.I can't find any 24v AC to 220/230v AC transformers.The current option I'm looking at is converting 24v AC to 24v DC and then convert 24v DC to 220/230v AC.The problem with this is that I firstly can't find any 24v AC to 24v DC converters and secondly this solution is presenting a lot of energy loss.What would your solution be?

author: moffy
author_rank: Super Contributor
timestamp: December 19, 2023, 05:30:50 am
content: You couldn't reasonably use just an AC to AC transformer because you would have to synchronise the rotation of the wind turbine perfectly to the mains frequency, which is impractical with variable wind as the motive force. So conversion to DC and then conversion to AC mains as in solar panels seems your best option. The 24V AC to DC converter is just a bridge rectifier with filtering caps, are we talking a single phase or three phase output from the turbine?

author: PCB.Wiz
author_rank: Super Contributor
timestamp: December 19, 2023, 06:00:57 am
content: Quote from: fish654321789 on December 19, 2023, 05:09:23 amFind and buy a commercial product,with the proper safety approvals and testing.

author: fish654321789
author_rank: Newbie
timestamp: December 19, 2023, 07:34:02 am
content: It's a three phase generator on the turbine.

author: Whales
author_rank: Super Contributor
timestamp: December 19, 2023, 07:34:16 am
content: This is a rather complex and dangerous task.24V @ 5kW -> 200 amps. That's a lot of current, you will need appropriate protection including fuses. Your wires will be particularly thick and expensive too. Even a 0.1 ohm resistance will make you lose 20 of your 24 volts (ohm's law) at that current level.To feed power back into the grid the AC waveform needs to be synchronised. You cannot do this with a wind turbine, you MUST convert it to DC and then back to AC using a "grid-tie inverter". You can buy these off the shelf (they're somewhat common for home solar users).If this is a project for fun then I'd recommend avoiding the high-voltage AC and avoiding 5kW, aim for something smaller and safer like a few hundred watts at low DC voltages (less than 50V). Some solar style equipment might be adaptable, including battery chargers. Perhaps use a car battery as your storage and then small buck & boost converters where needed to run your appliances. You can get fridges and other things that run off 12VDC or 24VDC too (models targeted at cars & campervans).

author: Zero999
author_rank: Super Contributor
timestamp: December 19, 2023, 10:09:49 am
content: Quote from: fish654321789 on December 19, 2023, 05:09:23 amWhat you're looking for is a bridge rectifier.The output voltage will be specified as the RMS (Root Mean Square) which means the voltage of a sine wave which will result in the same dissipation in a resistor, as steady DC. The rectifier will produce the peak voltage, minus a small voltage drop. The peak voltage is equal to the rmsvoltage multiplied by √2.VRMS= 24VACVP= VRMS√2 = 24×1.414 = 33.9VYour inverter must be capable of handling at least the peak voltage, plus a fair safety margin.Your wind turbine probably produces three phase, which requires six diodes. Use Schottky diodes with a very low voltage drop for high effciency.There will be some ripple, down to 87% of the peak voltage so the inverter must still work down below that, minus the diode losses.Choose an inverter with an input voltage range of 24V to 36V.