I attended the American Wind Energy Association’s 2011 Conference & Expo in Anaheim last week where I was able to see a lot of technology for turbines both large and small.
On the small side, at 3.5 and 7.5 kW, was Sonkyo Energy’s WINDSPOT turbine.
The WINDSPOT features a proprietary blade pitch control assembly, and the Spanish company owns International Application Publication No. WO 2010/034861 (’861 Application) directed to this technology.
Unfortunately, I was unable to find a corresponding English language patent application, so I was limited to the Abstract of the ’861 Application and my conversation with the folks at Sonkyo’s booth to explain the technology.
The ’861 Application describes a rotating headpiece including a shaft connected to a cross-piece (14), which is connected via intermediate mechanisms (5, 8-11) to the end supports of (7) of the blades (6).
When the cylinder shaft moves the cross-piece (14) the assembly varies the pitch of the blades (6). Counterweights (15) can also vary the blade pitch of the rotor head.
According to Sonkyo’s web site, its variable pitch technology “is a passive mechanism that uses the centrifugal force produced by the turning of the wind turbine to change the attack angle of the blades, which adjust themselves in a movement synchronized by the strength of the wind.”
At the utility scale, Muenster, Germany-based Kenersys’s 2.0 and 2.5 MW turbines employ the company’s SYNERDRIVE technology, which includes electrically excited synchronous generators.
Kenersys owns several international patent applications, including International Application Publication No. WO 2010/034760 (’760 Application), entitled “Excitation machine for a synchronous generator.” Again, there do not appear to be any English-language counterparts for this application, so we’re limited to the Abstract.
The ’760 Application is directed to an excitation machine for a synchronous generator (13, 14) wherein the synchronous generator comprises at least two excitation modules (10, 9; 8, 9). The first module (10, 9) is self-excited, and the second module (8, 9) is externally-excited.
According to the Abstract of the ’760 Application, the invention makes it possible to generate high outputs and provide cold-starting and operating capabilities at low rotational speeds or without connection to the utility grid.
Eric Lane is a patent attorney at Luce, Forward, Hamilton & Scripps in San Diego and the author of Green Patent Blog. Mr. Lane can be reached at firstname.lastname@example.org.