Direct Drive Linear Generator Wave Machine
After reviewing the wecTYPES and the wec Patents and numerouse theses & papers it was obvious that the bobbing float Point Absorber (PA) type with a Direct Drive Linear Generator power take off (PTO) would be the best for us because it is easiest, most reliable & cheapest to build.
Drawing of design, above, & photo of PA model, below
Investigations of linear generators led us to the above design.
Photo of one of the magnet plungers for testing in model.
It is well known that, doubling the speed of moving the magnet plunger past the wire coils will double the voltage (in general for open cuircuit voltage in generators).
The main problems with wave energy conversion are:
1. the long time period between
waves from 2 to 8 seconds
generally (avg, 5 sec.); and,
2. the irregular nature of successive
Hence, with respect to wave machine direct drive linear generators:
1. the stroke cycle is 2.5 sec (avg.)
which in a rotating generaor
would be 60/2.5 = 24 RPM (7.5
RPM for 8 sec waves); and,
2. the other problem is that each
cycle starts from zero movement
increasing to max movement
then ends with zero movement
so the generating stroke cycle is
not at contiuous speed and each
cycle starts from a dead stop
The voltage created by the generator is important because it is directly related to the gauge of wire in the coils with respect to the amperage that the generator can sustain before burning out. more