Changes
* Vestas Wind Energy Systems and General Electric are the major players in this technology.
* Patenting activity has seen high growth rate in the last two years.
* Research activity mainly going on rating and controlling of the Doubly-fed induction generation systems. Out of 140 patents 120 patents are discussing about controlling the DFIG.* Continuous Operation of the DFIG system during weak and storm winds, during grid voltage sags , and grid faults is one of the main concerns to the companiesare major issues in current scenario. Among 28 operation patentscovering DFIG operation, 24 patents are talking about focusing on grid connected mode of operation.* [http://www.woodward.com/ Woodward GMBH] is a new and fast developing player in this the field of DFIG technology having 10 patents on Operation, Regulation, Control and Protection of DFIG filed 10 patent applications in the Year field in year 2010, while it has no prior IP activity.* BrushIt is a known fact that the brush-less operation technology reduces the wear and tear and increases the efficiency and life of the system. This technology is protected by small players, in which Dual Stator Technology Corp plays major role.<br><br><br>
=Introduction=
