An energy generating system for transforming energy of fluid flow into electric energy, the system, at least in operation, comprising: a flow-changing member having a peripheral rim and mounted in a fluid path having a path surface, so as to be at least partially surrounded by said path surface, said flow-changing member being displaceable between a first position, in which at least a portion of the rim is spaced from a corresponding portion of the path surface to a first extent and a second position, in which said portion of the rim is spaced from said portion of the fluid path surface to a second extent greater than said first extent, so that increase of total volumetric flow rate of said fluid above a predetermined threshold to an increased volumetric flow rate is configured to induce displacement of said flow-changing member from said first position toward said second position, thereby causing the volumetric flow rate of said fluid at said spacing to be above said increased volumetric flow rate; and a turbine mounted in fluid communication with said fluid path at a location other than said spacing, whereby said displacement causes the volumetric flow rate of said fluid at said turbine to be below said increased volumetric flow rate.

A hydroelectric power generation apparatus includes a braking force generation unit configured to apply a braking force to rotation of a hydraulic turbine, and a controller configured to control the braking force generation unit to repeat increasing and decreasing the braking force to vary a rotational speed of the hydraulic turbine. Varying the rotational speed of the hydraulic turbine helps to flow away debris and the like adhering to hydraulic turbine blades. Preferably, the braking force generation unit includes an electrical, mechanical or fluid type braking device configured to apply a braking force to a rotary shaft of the hydraulic turbine. Preferably, the braking force generation unit includes a power generator configured to generate power through rotation of the hydraulic turbine, and the controller increases/decreases the braking force by varying power extracted from the power generator.

Disclosed herein are systems and methods method of verifying the configuration of an overspeed system for a shaft. The method comprises determining a first rotational speed of a shaft using an overspeed system. The overspeed system comprises a toothed wheel that rotates in relation to the rotational speed of the shaft. The method further comprises determining a second rotational speed of the shaft using a vibration sensing system for monitoring vibration of the shaft. The method further comprises comparing the first rotational speed of the shaft and the second rotational speed of the shaft to verify a configuration of the overspeed system.

A hydraulic rotating machinery (HRM) system provides optimal energy efficiency over a very wide conditions of service (COS) range by configuring a plurality of variable speed HRMs in a cluster. The HRMs are interconnected by one or more valves that can be actuated by a controller to configure and vary a flow path through which a process fluid flows from an inlet to an outlet. By actively selecting which of the HRMs are included in the flow path, the interconnections therebetween, and the operating speeds thereof, the controller ensures that the HRM cluster continues to operate at optimal efficiency as the COS fluctuates over a very wide range. The HRMs can be identical to each other, or can vary in design. The HRM system can be implemented for storage and retrieval of green energy. The controller can also monitor the health of the cluster and/or of the associated process.

A hydraulic rotating machinery (HRM) system provides optimal energy efficiency over a very wide conditions of service (COS) range by configuring a plurality of variable speed HRMs in a cluster. The HRMs are interconnected by one or more valves that can be actuated by a controller to configure and vary a flow path through which a process fluid flows from an inlet to an outlet. By actively selecting which of the HRMs are included in the flow path, the interconnections therebetween, and the operating speeds thereof, the controller ensures that the HRM cluster continues to operate at optimal efficiency as the COS fluctuates over a very wide range. The HRMs can be identical to each other, or can vary in design. The HRM system can be implemented for storage and retrieval of green energy. The controller can also monitor the health of the cluster and/or of the associated process.