Abstract: A turbine for use with a turbine generator, the turbine including at least one turbine blade for positioning in a flowpath, a hub mounting the at least one turbine blade, and a rotatable shaft in operational communication with the hub via a hinge assembly, an axis of the hub being independent of an axis of the shaft. The hinge assembly is disposed between the shaft and the hub and configured to adjust an angle therebetween. A controller assembly is configured to adjust at least one operational characteristic of the hinge assembly during turbine operation. In one embodiment the operational characteristic is a teeter angle of the hinge assembly. In one embodiment operational characteristic is a stiffness or damping force. Methods for using and controlling a fluid turbine are also disclosed.

Abstract: A turbine for use with a turbine generator, the turbine including at least one turbine blade for positioning in a flowpath, a hub mounting the at least one turbine blade, and a rotatable shaft in operational communication with the hub via a hinge assembly, an axis of the hub being independent of an axis of the shaft. The hinge assembly is disposed between the shaft and the hub and configured to adjust an angle therebetween. A controller assembly is configured to adjust at least one operational characteristic of the hinge assembly during turbine operation. In one embodiment the operational characteristic is a teeter angle of the hinge assembly. In one embodiment operational characteristic is a stiffness or damping force. Methods for using and controlling a fluid turbine are also disclosed.

Abstract: A three-phase electric motor is partially braked as a result of self-excitation when the power supply is disconnected and a capacitor is connected across one of the windings. The motor is then rapidly brought to a standstill by applying a short-circuit (or connecting a relatively low impedance) across one or both of the other windings, and essential condition being that the short-circuit is initiated within a predetermined range of values of phase angle in a waveform of the self-excitation. Preferred ranges of phase angle are established for selected configurations of mechanical and electronic short-circuiting switches.