Abstract: A system for monitoring polarization and conduction of a thyristor includes a transformer configured to generate a secondary current from a triggering current waveform applied to a gate of the thyristor; a converter configured to convert the secondary current into a monitored voltage; a first hysteresis comparator configured to generate a first voltage pulse based on the monitored voltage when the triggering current waveform includes a first current pulse; a second hysteresis comparator configured to generate one or more second voltage pulses based on the monitored voltage when the triggering current waveform includes one or more second current pulses; a monitoring unit configured to receive the first and the one or more second voltage pulses, and determine whether the triggering current waveform satisfies pre-defined characteristics, and to determine whether a current flowing between the anode and cathode of the thyristor satisfies additional pre-defined characteristics.

Abstract: An air injection device for a hydraulic turbine includes: a body having a first end and a second end; an air injection passage extending through the body from the second end to the first end; a protrusion disposed at the first end of the body; and one or more air injection holes disposed in the protrusion.

Abstract: An aeration apparatus for aerating water discharged from a hydraulic turbine includes: a manifold disposed within a crown of a runner of the hydraulic turbine; a plurality of radial pipes extending radially from an outer perimeter of the manifold and in fluid communication with the manifold; and one or more air injectors having a first end disposed within an aeration pipe, each of the one or more air injectors having a second end extending into a nozzle at a first end of one of the radial pipes. Rotation of the aeration apparatus resulting from rotation of the runner causes pumping of water from the manifold through the radial pipes past the one or more air injectors, and water flowing past the one or more air injectors causes air to become entrained in the water. The radial pipes discharge the water and entrained air from the aeration apparatus.

Abstract: A guide bearing system including a pad adjuster to traverse at least one bearing in a direction to adjust a radial clearance. The system can further include a sensor for measuring deviations in the radial clearance. In some embodiments, the guide bearing system includes a controller that receives a distance signal from the sensor measuring the radial clearance and signals the pad adjuster to traverse the at least one bearing to compensate for the deviations in the radial clearance.

Abstract: A hydro turbine assembly includes a hub configured to rotate about a center axis and configured to be mounted in a water passage. The hub includes an upstream end, a downstream end and an outer surface between the upstream and downstream ends. The hub includes at least three mounting recesses arranged in the outer surface wherein each mounting recess includes a first hub mounting surface and a second hub mounting surface, and the second hub mounting surface is downstream and radially inward of the first hub mounting surface. The assembly includes at least three runner blades each including a base configured to seat in a respective one of the mounting recesses, wherein the base includes a first blade mounting surface arranged to abut the first hub mounting surface and a second blade mounting surface arranged to abut the second hub mounting surface.