A hydroelectric power generation system includes: a generator driven by the hydraulic turbine; a head adjuster adjusting an effective head of the hydraulic turbine; and a controller cooperatively executing: flow rate control for controlling the generator such that a flow rate in the hydraulic turbine is brought close to a target flow rate; and head adjusting control for adjusting the effective head of the hydraulic turbine using the head adjuster such that the effective head of the hydraulic turbine falls within a first range.

A hydroelectric power generation system includes: a generator driven by the hydraulic turbine; a head adjuster adjusting an effective head of the hydraulic turbine; and a controller cooperatively executing: flow rate control for controlling the generator such that a flow rate in the hydraulic turbine is brought close to a target flow rate; and head adjusting control for adjusting the effective head of the hydraulic turbine using the head adjuster such that the effective head of the hydraulic turbine falls within a first range.

A control device estimates a flow rate and an effective height difference of a fluid machine based on a characteristic detectable with regard to a rotating electrical machine and correlating with the flow rate and the effective height difference of the fluid machine. A total flow rate in a pipe system is estimated based on these values estimated by the control device and a flow resistance characteristic line, and cooperative control of the fluid machine and the flow rate control valve is performed such that the estimated value of the total flow rate becomes close to a target flow rate of the total flow rate in the pipe system.

A control device estimates a flow rate and an effective height difference of a fluid machine based on a characteristic detectable with regard to a rotating electrical machine and correlating with the flow rate and the effective height difference of the fluid machine. A total flow rate in a pipe system is estimated based on these values estimated by the control device and a flow resistance characteristic line, and cooperative control of the fluid machine and the flow rate control valve is performed such that the estimated value of the total flow rate becomes close to a target flow rate of the total flow rate in the pipe system.

A buoyancy powered electrical generator. A source of compressed gas is provided. The gas, which may be air, is compressed using a conventional compressor. In one embodiment, the compressor is powered by a windmill, turbine, or other conventional means. The compressed gas may be stored in a tank for an indefinite period. If necessary, the tank may be transported to the generator via truck, train or other conventional transportation means. During generation, compressed gas is released into a series of hollow, flooded drums mounted on a wheel in a liquid filled chamber. Introducing gas into the drums closes a valve in the drums and evacuates liquid from the drums, causing the drums to become buoyant. The buoyant drums exert a buoyant force on the wheel, causing it to rotate. The wheel is connected to a rotor in a magnetic generator. Rotating the wheel turns the rotor, thereby generating electricity.

A buoyancy powered electrical generator. A source of compressed gas is provided. The gas, which may be air, is compressed using a conventional compressor. In one embodiment, the compressor is powered by a windmill, turbine, or other conventional means. The compressed gas may be stored in a tank for an indefinite period. If necessary, the tank may be transported to the generator via truck, train or other conventional transportation means. During generation, compressed gas is released into a series of hollow, flooded drums mounted on a wheel in a liquid filled chamber. Introducing gas into the drums closes a valve in the drums and evacuates liquid from the drums, causing the drums to become buoyant. The buoyant drums exert a buoyant force on the wheel, causing it to rotate. The wheel is connected to a rotor in a magnetic generator. Rotating the wheel turns the rotor, thereby generating electricity.

A system for controlling the flow of turbined water from a plurality of hydroelectric plants arranged in series along a watercourse with an open channel flow, defining upstream of each plant, a plurality of head races subject respectively to hydraulic flow and level constraints. The flow of water turbined by each of the plants is controlled by a flow setpoint. The system includes regulation of a global electrical production power set-point for the plurality of hydroelectric plants by a flow regulation setpoint taking into account the flow setpoint of each of the plants. The flow regulation setpoint determined by the regulation is weighted for each of the plants by weighting coefficients as a function of the respective hydraulic characteristics of the head plurality of races.

A system for controlling the flow of turbined water from a plurality of hydroelectric plants arranged in series along a watercourse with an open channel flow, defining upstream of each plant, a plurality of head races subject respectively to hydraulic flow and level constraints. The flow of water turbined by each of the plants is controlled by a flow setpoint. The system includes regulation of a global electrical production power set-point for the plurality of hydroelectric plants by a flow regulation setpoint taking into account the flow setpoint of each of the plants. The flow regulation setpoint determined by the regulation is weighted for each of the plants by weighting coefficients as a function of the respective hydraulic characteristics of the head plurality of races.

A system for generating power from a flow of liquid having at most fifty feet of head and a flow rate of at most 300 cubic feet per second, includes: an axial-flow turbine, a penstock, an intake, a generator, and a control circuit. Each blade of the turbine runner is releasably coupled to the hub and each blade: 1) is configured to extract energy from liquid flowing through the runner by rotating the hub when the flow of liquid contacts the blade, and 2) has a pitch that is adjustable. The length of the penstock is adjustable. The generator is operable to generate electric power from rotation of the turbine. The control circuit to determines changes in the flow of liquid and in response modifies at least one of the following: 1) the speed of the axial-flow turbine's hub, and 2) the flow of liquid that the runner receives.

A system for generating power from a flow of liquid having at most fifty feet of head and a flow rate of at most 300 cubic feet per second, includes: an axial-flow turbine, a penstock, an intake, a generator, and a control circuit. Each blade of the turbine runner is releasably coupled to the hub and each blade: 1) is configured to extract energy from liquid flowing through the runner by rotating the hub when the flow of liquid contacts the blade, and 2) has a pitch that is adjustable. The length of the penstock is adjustable. The generator is operable to generate electric power from rotation of the turbine. The control circuit to determines changes in the flow of liquid and in response modifies at least one of the following: 1) the speed of the axial-flow turbine's hub, and 2) the flow of liquid that the runner receives.