Abstract: A method for providing robust and reliable transmission of shaft encoder signals. Initially, the differentially encoded shaft encoder signals are received. The shaft encoder signals are converted into single-ended electrical signals. These single-ended electrical signals are then converted into optical signals. Finally, the optical signals are transmitted through optical conductors.

Abstract: A fiber optic safety system for a wind turbine. The system includes a series of switching elements coupled together to indicate a fail-safe condition of the wind turbine. The system also includes a plurality of optical transceivers, a plurality of optical conductors, and a blade pitch controller. Each of the optical transceivers is disposed at least at a down tower and an up tower of the wind turbine. The optical conductors are then coupled to the optical transceivers to carry optical signals between the down tower and the up tower. The blade pitch controller is connected to an up-tower optical transceiver, where the controller controls wind turbine blades.

Abstract: A method for providing robust and reliable transmission of shaft encoder signals. Initially, the differentially encoded shaft encoder signals are received. The shaft encoder signals are converted into single-ended electrical signals. These single-ended electrical signals are then converted into optical signals. Finally, the optical signals are transmitted through optical conductors.

Abstract: A method and apparatus for non-volatile overspeed protection is described. The present invention provides a method and apparatus for non-volatile overspeed detection to provide turbine rotational speed safety during a power outage. In one embodiment, aerodynamic braking is used to slow rotation of a rotor of the wind turbine. If an overspeed condition continues after application of aerodynamic braking, mechanical braking is used to reduce the rotational speed of the rotor. Power is supplied by a non-volatile power source to continue overspeed detection during a power outage. A low-pressure trigger valve is used to apply a mechanical brake when hydraulic pressure in the braking system falls below a predetermined threshold.