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 method for harnessing wave energy includes providing a vehicle to a body of water, the vehicle. The method includes submerging the vehicle to a depth in the body of water. The method includes operating the motor-generator of the vehicle in the first quadrant of the motor-generator. The method includes detecting a phase of a wave in the body of water based information from the processor of the detected phase. The method includes orienting the vehicle to lag the phase of the wave based on the detected phase of the wave. The method includes synchronizing an inertial acceleration of the vehicle to movement of the wave. The method includes switching the motor-generator to the second quadrant for generation mode to convert energy from the movement of the wave to electrical energy. The method includes storing the energy from the wave in the rechargeable battery source.

A fuel system includes a pump unit having at least a fixed displacement pump supplying pressurized flow. A fuel control assembly receives flow from the pump unit and includes at least one metering valve and at least one throttling valve. A control (bypass valve control) for the fixed displacement pump receives first and second pressure signals indicative of a pressure differential across the throttling valve, or across the metering valve/throttling valve combination, for altering output from the fixed displacement pump in response to the pressure differential. In other embodiments, the pump unit includes a centrifugal pump and a fixed displacement pump that can be fully or partially redundant depending on sizing of the pumps, and the system requirements.

A system, method, and computer program to adjust the effective width of centrifugal fan wheel(s) in a fan system during operation. The reason for the adjustment is to prevent stall when running the fan over a wider range of system operating points. This is of particular use in high turndown variable air volume systems commonly encountered in HVAC systems. An additional option function is to isolate a single fan, in a fan system, if that fan should fail, to prevent reverse flow through the failed fan.

A method is proposed for detecting damage to at least one rotor blade of a wind turbine, including the following steps, monitoring during rotation of the at least one rotor blade at least one internal air condition inside a blade root of the at least one rotor blade, wherein the internal air condition is affected by a centrifugal effect pumping the air inside the at least one rotor blade from a root end towards a tip end and out of at least one hole of the at least one rotor blade, detecting damage to the at least one rotor blade based on the at least one monitored internal air condition. Further, a wind turbine and a device as well as a computer program product and a computer readable medium are suggested for performing the method.

One or more controllers may perform one or more methods to control one or more air deflector units of one or more wind turbine rotor blades. The methods include per-blade control methods that may be performed, e.g., to reduce blade loading caused by wind gusts. The methods also include collective control methods that may be performed, e.g., to reduce tower motion and/or rotor speed.

A method for harnessing wave energy includes providing a vehicle to a body of water, the vehicle. The method includes submerging the vehicle to a depth in the body of water. The method includes operating the motor-generator of the vehicle in the first quadrant of the motor-generator. The method includes detecting a phase of a wave in the body of water based information from the processor of the detected phase. The method includes orienting the vehicle to lag the phase of the wave based on the detected phase of the wave. The method includes synchronizing an inertial acceleration of the vehicle to movement of the wave. The method includes switching the motor-generator to the second quadrant for generation mode to convert energy from the movement of the wave to electrical energy. The method includes storing the energy from the wave in the rechargeable battery source.