Windward
Mechanical
- Dec 25, 2002
- 181
Use hydraulics. I am not suggesting a 100% hydraulic drive such as attempted by Parker Hannifin, or Mitsubishi with their Sea Angel. These, and all other such attempts, failed. Not technically, but economically.
In my proposal, analysis attached, a variator would handle as little as 11% of the total power. A hydraulic variator would be the most effective. Most of the power is handled by a gearbox.
This technology is not only simple, it would be the most important improvement possible in wind turbines because it would eliminate the power electronics. Power electronics are inefficient, delicate and expensive, and they produce dirty power. Wind power cannot reach its full potential so long as it requires power electronics, as every current commercial turbine does whether geared or direct drive.
Excepting DeWind, which demonstrated a way to eliminate the power electronics with their 8.2 and 9.2 turbines. I am proposing a different way.
It is not possible to eliminate the power electronics with direct drive. Furthermore, direct drive is the heaviest and most expensive technology. It has other serious problems that cannot be solved, such as the requirement for huge quantities of expensive rare earth magnets which will become ever more expensive and difficult to obtain. Direct drive should be relegated to the museums.
But the folly of direct drive is maintained by a powerful cult whose members insist that it is more reliable than geared turbines because it has fewer parts. This is a specious argument. It ignores at least two other important factors that determine reliability: the reliability of each part and the method of mounting and operating the parts.
One reason that gearboxes have unjustly acquired a bad reputation in wind turbines is because of the way in which they are mounted in a typical wind turbine. In these arrangements, the gearbox serves as a bearing for the rotor shaft. This imposes harmful external forces on the gearbox that it should not be required to handle. Some manufacturers such as Alstom, now owned by GE, recognized this problem and invented a solution:
Another reason is that, so far, all wind turbine gearboxes have been of the planetary type, which suffers from numerous inherent faults. That subject requires a doctoral thesis, so I won’t try to explain it here. I have written a paper on it. I will provide it upon request. It is a short paper.
A third reason is the effect of reverse or transient torque on wind turbine gearboxes. If it is not eliminated, gearboxes cannot achieve their potential life. See the excellent articles on the Windpower Engineering & Development website about torque reversal, for instance:
and others of which there are many, such as:
Gearboxes can be extremely reliable. A ship’s gearbox can outlast three ships if treated properly. A wind turbine gearbox can be made as reliable as that by adopting a few simple changes in the way in which it is mounted and operated, and by replacing the planetary type with the far more effective multi-branch parallel shaft type.
The only way to greatly improve wind turbines is to give up the fanatic, false belief in direct drive and come to our senses about the value of geared turbines.
The best way to bring wind power to its fullest and most effective use is to combine hydraulic power with a gearbox, as explained in the attachment.
In my proposal, analysis attached, a variator would handle as little as 11% of the total power. A hydraulic variator would be the most effective. Most of the power is handled by a gearbox.
This technology is not only simple, it would be the most important improvement possible in wind turbines because it would eliminate the power electronics. Power electronics are inefficient, delicate and expensive, and they produce dirty power. Wind power cannot reach its full potential so long as it requires power electronics, as every current commercial turbine does whether geared or direct drive.
Excepting DeWind, which demonstrated a way to eliminate the power electronics with their 8.2 and 9.2 turbines. I am proposing a different way.
It is not possible to eliminate the power electronics with direct drive. Furthermore, direct drive is the heaviest and most expensive technology. It has other serious problems that cannot be solved, such as the requirement for huge quantities of expensive rare earth magnets which will become ever more expensive and difficult to obtain. Direct drive should be relegated to the museums.
But the folly of direct drive is maintained by a powerful cult whose members insist that it is more reliable than geared turbines because it has fewer parts. This is a specious argument. It ignores at least two other important factors that determine reliability: the reliability of each part and the method of mounting and operating the parts.
One reason that gearboxes have unjustly acquired a bad reputation in wind turbines is because of the way in which they are mounted in a typical wind turbine. In these arrangements, the gearbox serves as a bearing for the rotor shaft. This imposes harmful external forces on the gearbox that it should not be required to handle. Some manufacturers such as Alstom, now owned by GE, recognized this problem and invented a solution:
Another reason is that, so far, all wind turbine gearboxes have been of the planetary type, which suffers from numerous inherent faults. That subject requires a doctoral thesis, so I won’t try to explain it here. I have written a paper on it. I will provide it upon request. It is a short paper.
A third reason is the effect of reverse or transient torque on wind turbine gearboxes. If it is not eliminated, gearboxes cannot achieve their potential life. See the excellent articles on the Windpower Engineering & Development website about torque reversal, for instance:
and others of which there are many, such as:
Gearboxes can be extremely reliable. A ship’s gearbox can outlast three ships if treated properly. A wind turbine gearbox can be made as reliable as that by adopting a few simple changes in the way in which it is mounted and operated, and by replacing the planetary type with the far more effective multi-branch parallel shaft type.
The only way to greatly improve wind turbines is to give up the fanatic, false belief in direct drive and come to our senses about the value of geared turbines.
The best way to bring wind power to its fullest and most effective use is to combine hydraulic power with a gearbox, as explained in the attachment.
