A hydroelectric power generation system includes a water turbine, a generator connected to the water turbine, and a controller. The water turbine is arranged in a flow path through which a fluid flows. The controller performs a pressure control by controlling the generator to regulate a pressure of the fluid downstream of the water turbine. The pressure control includes a first control regulating the pressure in parallel with a regenerative operation of the generator, and a second control regulating the pressure in parallel with a power running operation of the generator.

A wheel-mounted air compression apparatus for maintaining a predetermined inflation pressure of a tire mounted on a wheel of a vehicle and the tire having an inflation port includes a housing defining an air compression chamber and has an air compressor device positioned therein. The apparatus includes a plurality of support legs spaced apart from one another. Each support leg is attached to the housing and extends away therefrom and may include a pair of sleeves that are length-adjustable for mounting to wheels of various sizes. A pressure sensor is situated in the housing and operably connected to the air compressor and to a nozzle for determining a current pressure of air within the tire. A controller or other electronics cause the air compressor to pump air into a tire if the air pressure therein is detected as declining below a predetermined amount.

A fuel flow control system is configured to perform a method including: setting a fuel flow demand proportional to compressor discharge pressure; detecting an actual fuel flow; and applying an enhanced schedule for fuel flow demand while fuel flow demand is less than a predefined proportion of actual fuel flow.

A hydroelectric power generation system includes a water turbine, a generator connected to the water turbine, and a controller. The water turbine is arranged in a flow path through which a fluid flows. The controller performs a pressure control by controlling the generator to regulate a pressure of the fluid downstream of the water turbine. The pressure control includes a first control regulating the pressure in parallel with a regenerative operation of the generator, and a second control regulating the pressure in parallel with a power running operation of the generator.

The present invention is directed to a method for controlling the outlet temperature of an oil injected compressor or vacuum pump comprising a compressor or vacuum element provided with a gas inlet, an element outlet, and an oil inlet, said method comprising the steps of: measuring the outlet temperature at the element outlet; and controlling the position of a regulating valve in order to regulate the flow of oil flowing through a cooling unit connected to said oil inlet; whereby the step of controlling the position of the regulating valve involves applying a fuzzy logic algorithm on the measured outlet temperature; and in that the method further comprises the step of controlling the speed of a fan cooling the oil flowing through the cooling unit by applying the fuzzy logic algorithm and further based on the position of the regulating valve.

A system includes a fluid pump and a first pressure sensor disposed on or near an inlet of the fluid pump. The system further includes a second pressure sensor disposed on or near an outlet of the fluid pump and a control system. The control system includes a processor configured to receive a first signal from the first pressure sensor. The processor is further configured to receive a second signal from the second pressure sensor, and to derive a pump slip measure based on the first signal and the second signal.

A fan failure backup apparatus includes a first fan module and a second fan module. When a second control unit of the second fan module realizes that the first fan module is failed through a first control unit of the first fan module, and the second control unit realizes that the second fan module is not failed, the second control unit controls the second fan module to additionally enhance a pressure-flow characteristic of a second fan unit of the second fan module.

A fuel flow control system is configured to perform a method including: setting a fuel flow demand proportional to compressor discharge pressure; detecting an actual fuel flow; and applying an enhanced schedule for fuel flow demand while fuel flow demand is less than a predefined proportion of actual fuel flow.

A method (30) of controlling fuel flow in a gas turbine engine. First, detect a surge condition. Set fuel flow demand (W.sub.f_D) proportional to compressor discharge pressure (P.sub.30). Detect actual fuel flow (W.sub.f_A). Then apply an enhanced schedule (50) for fuel flow demand (W.sub.f_D) while fuel flow demand (W.sub.f_D) is less than a predefined proportion (k) of actual fuel flow (W.sub.f_A). Also a gas turbine engine (10), fuel flow system (68) and fuel flow control system (76) each implementing the method (30).

A wheel-mounted air compression apparatus for maintaining a predetermined inflation pressure of a tire mounted on a wheel of a vehicle and the tire having an inflation port includes a housing defining an air compression chamber and has an air compressor device positioned therein. The apparatus includes a plurality of support legs spaced apart from one another. Each support leg is attached to the housing and extends away therefrom and may include a pair of sleeves that are length-adjustable for mounting to wheels of various sizes. A pressure sensor is situated in the housing and operably connected to the air compressor and to a nozzle for determining a current pressure of air within the tire. A controller or other electronics cause the air compressor to pump air into a tire if the air pressure therein is detected as declining below a predetermined amount.