Coil design and magnet orientation in a unique generator

Question

First, I am not an electrical engineer - I am a hobbyist building a prototype linear-stlye generator based on an idea I had which, for various reasons, cannot be built with magnets that pass completely inside of coil(s) like most of the ones I have seen described for wave energy capture and other reciprocating motions. I understand the basic concepts of electromagnetism and have read a great deal, but I can't find anything which describes the factors I would like to know about in any detail.

I did find one company, Windtronics who have a wind generator that has some of the same constraints as what I am working under. Their 'BTPS' (blade tip power system) has magnets that move past coils in a fixed housing, and since the magnets are attached to the rim of the wind vane assembly, they can't be completely enclosed by the coils.

Unfortunately, none of the drawings I have found of their device clearly show how the magnets and coils are oriented with respect to each other - which is the question I have: How would you orient magnets at the end of a spoke or arm that moves near coils (and what orientation should these coils with respect to the end-of-arm magnets, and how should they be wired together) so that the result has the maximum electrical generation efficiency?

I can envision many possible configurations, but wanted to solicit some expert guidance before wasting a lot of time building something sub-optimal. Any pointers or discussion are welcomed.

Answer 1

I have got some ideas regarding the question you asked. First, thats a good idea to keep the generation part on the rim.

If i am right, you are asking about the construction of the generation part. Right? The magnets used are generally called POLES in electrical engineering(where the magnetic field comes out of the magnets). These poles traverse the stationary coil in the rim. Creating current in them.

Coming to the construction part, let us consider copper wires are being used(easy for explanation too). The length of the copper wire is along the direction of flow of wind.(i.e., perpendicular to the plane of rotation). I know, the length of the wire will be short. But, one can connect a lot of these wires in parallel(to increase the current) and these arrangements in series(to increase the voltage).

From the above construction,(if all the copper wires are connected in parallel) one can get AC power of high frequency(f=w*p/120,w is angular speed of the turbine,p is number of poles, f is frequency of operation). Here, the number of poles=number of vanes(if taken, each magnet per vane). In order to maintain the frequency(=60Hz), one can use the above technique so that, a single circuit(parallel ones) takes some time to get inside the field again.

If you want to construct on your own, its a difficult task. As, you need to get the material of the vane strong enough to hold the magnets(POLES), withstand the wind strength and most important, its difficult to maintain same pitch for all the vanes(manufacturing).

If you don't understand any part of it, feel free to comment.