Ideally, the pitch should be set so the blade's speed through the air is 7 times the wind speed. One thing you should try is changing the pitch of the blades (rotate them about the rod you have fastening them to the center). A commercial turbine, blades a little shorter than yours, (made with alternator similar to car alternator except better laminations & permanent magnet rotor) gets 500W maximum in 30MPH steady wind. There is something wrong with the pitch/shape of the blades. You reduced the length of the blades, & the speed went up! That shouldn't happen. There is something else that is not right (that may be the more serious problem why you are not getting more power). You also have to position the magnets carefully to minimize "cogging torque" which can prevent the turbine from starting up. This gets rid of the rotor power loss, but because of the thick laminations in the stator, the losses there are high. What some have done is to replace the rotor electromagnet with rare-earth magnets. What do you think that fan is for?) The steel laminations in the stator are way too thick causing high eddy-current losses. In their intended use, they are lucky to be 50% efficient (who cares? There is a 100HP engine behind it. Car alternators are designed to be CHEAP. Your statement "Using a car alternator for a wind turbine might not be a good idea" except replace "might" with "IS". Now thats our take having fun with the winds and building this wind turbine, hit thumbs up if you loved the built and we will see you soon in the next one Now thats something we will cover in another video, so drop down your suggestions in the comments section below. Using a car alternator for a wind turbine might not be a good idea but there are some tweeks that we are looking forward to overcome these issues like replacing the current rotor with a permanent magnet one and increasing the rotor speed using a higher gear ratio between the blades and the alternator. The maxiumum output we were able to get was arround 50 watts which barely compensates the amount of power we are using to magnetize the rotor coil and is way less than what we have expected. We were aiming for 700 RPM while the turbine initially achieved 200 so we switched to shorter blades which did increased the RPM but still we are half way down there at 350 RPM. This prevents the turbine from overspeeding as the blades are not following the wind direction anymore.Īside from having this much wind we are unable to get the required RPM. Now its time to take our wind turbine on the roof our workspace and then we have fastened the turbine unit with the plate of our post and done some wiring work by attaching the rotor coil to energize our electromagnet and also made the connetion for our main output possitive terminal and the whole body as negative terminal.The wind was blowing quiet alot and if you have noticed the tail started furling towards left, this happens when the blades achieve momentum as turbine reach its threshold speed, which can be lowered by decreasing the size of tail and its weight and vice versa. Now its time to built the frame for our wind generator. So we have sucessfully hacked this alternator and its producing 18v at arround 700 RPM besides that the rotor coil is drawing nearly 30 watts of power from a 3 cell lithium battery. So we have got the alternator dissassembled and as you can see over here this commutator provides the power to the rotor in order to magnetize it and this connector that might seems like its connected to the rotor is not, because there is a voltage regulator in between that makes sure that regardless of the engine speed the alternator generates consistent voltage so we need to bypass the voltage regulator andd directly connect a pair of wires to the carbon brushes to magnetize the rotor coil using an external battery pack. For that there in an oil pump / peristaltic pump that we dont need anymore so we unscrewed that and now we are ready to remove the pully and the cooling fan behind that. In order to make this alternator usefull for our wind turbie we have decided to do some modifications & alteration.
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