Abstract: A fuel supply device supplying a fuel stored in a fuel tank to an engine includes a low-pressure pump configured to feed the fuel, a high-pressure pump configured to compress the fuel discharged from the low-pressure pump and to feed to the engine, a first low-pressure passage member configured to define a first fuel passage from the low-pressure pump to the high-pressure pump, and a second low-pressure passage member configured to define a second fuel passage branched from the first fuel passage at a low-pressure junction portion and joining the first fuel passage at a low-pressure confluence portion, wherein the first fuel passage and the second fuel passage are different in at least one of (i) temperatures of the fuels that flow through the fuel passages and (ii) passage lengths of the fuel passages from the low-pressure junction portion to the low-pressure confluence portion.

Abstract: A delivery device for delivering a medium and for heating the medium to be delivered, having a vehicle pump, an electric motor for driving the vehicle pump and a control unit for controlling the electric motor. For heating the medium in the vehicle pump, the control unit is designed to generate a first alternating electrical current in a conductor winding of the electric motor. This first alternating electrical current induces eddy currents in a component of the delivery device, by which the medium can be heated.

Abstract: The invention relates to a fuel injector, in particular a common-rail injector (1), comprising an injector housing (2), in which a nozzle needle (8), which is arranged in such a way that the nozzle needle can be moved in a reciprocating manner, is arranged in a high-pressure chamber (6) in order to open and close at least one injection opening (5), which nozzle needle bounds a control chamber (20) by means of one end face and interacts with a nozzle body seat (10) by means of the other end face in order to open and close the injection opening (5). The nozzle needle (8) has a first sleeve-shaped supporting element (14), to which force is applied in the closing direction of the nozzle needle (8). In addition, the nozzle needle (8) has a second sleeve-shaped supporting element, which surrounds the nozzle needle (8) and which is arranged in the direction of the end face of the nozzle needle (8) that is close to the control chamber.

Abstract: Fuel injection valve having a magnet armature (18) which interacts with a valve seat (19), which is formed on a valve piece (15), in order to open and close an outflow opening (20), wherein the magnet armature (18) can be moved away from the valve seat (19) by an electromagnet (24). A valve piece (15) delimits a control chamber (12), wherein the outflow opening (20) opens into the control chamber (12), and the control chamber (12) can be charged with fuel at high pressure that exerts a hydraulic force on the valve piece (15). Between the magnet armature (18) and the valve piece (15), there is arranged a bracing element (30) which is preloaded against the valve piece (15) and which exerts a force on the valve piece (15) in the region of the outflow opening (20) in the direction of the control chamber (12).

Abstract: An injector, comprising, an injector body comprising, an inner wall that defines an injector cavity for fluid, at least one inlet channel into the injector cavity, and at least one outlet channel from the injector cavity, a plunger that defines at least one passageway between the injector cavity and the at least one outlet channel, the plunger being movable longitudinally in the injector cavity between at least: a first open arrangement in which the at least one passageway is positioned to direct fluid into the at least one outlet channel at a first position, and a second open arrangement in which the at least one passageway is positioned to direct fluid into the at least one outlet channel at a second position different from the first position.

Abstract: A tool for removing fuel injectors from a head assembly is disclosed that is comprised of a bolt, a dual-tined fork, and a plate that fit into the existing hold-down bolt holes in a head assembly and grooves in the fuel injectors.

Abstract: A valve is provided, in particular an injection valve, having a valve seat and a valve needle which extends along a closing direction for the most part, the valve seat having a valve-seat surface, and a valve-closing element is mounted on an end of the valve needle facing the valve seat, the valve-closing element being able to be moved between an open position and a closed position, and the valve-closing element together with the valve-seat surface forming a sealing seat in the closed position, the valve-closing element having a greater core hardness and/or surface hardness than the valve-seat surface.

Abstract: Recent exhaust gas regulation requires reduction of an amount and quantity of particulate matter included in an exhaust gas, and a normal maximum fuel pressure may be increased to approximately 35 MP. When the normal maximum fuel pressure is 35 MPa, a fuel injection valve is required to work for example at a pressure up to 45 MPa. In such a condition, a fluid force may exceed a valve opening force depending on a seat diameter, and a needle valve cannot be kept open and closed, when opening thereof is required.

Abstract: A method of operating a passive entry passive start (PEPS) system includes authenticating the mobile wireless device, detecting a presence of the mobile wireless device in a specified location in an interior of the vehicle, and calibrating one or more operating parameters of the PEPS system based on radio frequency (RF) performance characteristics of the mobile wireless device.

Abstract: There is provided a controller for a vehicle that can execute, while the vehicle is stationary or moving, control of automatically stopping an engine upon determining that automatic stop conditions are met, and automatically restarting the engine upon determining that automatic restart conditions are met while automatic engine stop is in effect. At a time of first engine restart in one trip, the controller diagnoses whether a system that automatically restarts the engine is normal or abnormal. The automatic stop conditions for in-motion automatic engine stop include automatic stop execution conditions that are set based on a state of the vehicle, and automatic stop permit conditions that are set based on a travel environment. The controller sets the automatic stop permit conditions such that determination criteria are more stringent as a cumulative number of times of in-motion automatic engine stop in one trip is smaller.

Abstract: A system may include a first bus transfer switch configured to open and close connections between a generator control unit, a pilot permanent magnet generator stage of an independent speed variable frequency (ISVF) generator, and an external power source. The system may further include an inverter configured to set a main field winding of the ISVF generator into a motor state. The system may also include a second bus transfer switch configured to open and close a connection between a main armature winding of the ISVF generator, a power distribution bus, and a motor start driver configured to send a current through the main armature winding to generate a magnetic field pattern that causes the rotor to turn, enabling startup of an engine.

Abstract: A starter for an engine is equipped with a planetary gear train as a torque variator to change torque used to start the engine. The torque variator is capable of changing the degree of torque which is transmitted between a planetary carrier and an outer gear of the planetary gear train, thereby changing a ratio of speed of a sun gear to speed of the planetary carrier of the planetary gear train to increase or decrease the degree of torque required to start the engine. This ensures the stability in starting the engine, for example, in cold conditions and achieves a quick start of the engine as needed.

Abstract: An integrated starter and generator (ISG) system of a vehicle includes: a planetary gear set including a sun gear, a planet carrier, and a ring gear as rotation elements of the planetary gear set; and an integrated starter and generator (ISG) functioning as a motor and a generator, and including a stator and a rotor. The planetary gear set and the ISG are disposed in a crankshaft pulley of an engine such that torque of a crankshaft of the engine is increased and is transmitted to the ISG when generating electricity and torque of the ISG is decreased and is transmitted to the crankshaft of the engine when starting.

Abstract: An ignition apparatus for internal combustion engines is provided. The ignition apparatus is equipped with an ECU. The ECU monitors a path length of a discharge of a spark for a period of time in which a second circuit delivers or inputs energy in the form of a threshold value determination. When the path length has become too short, the ECU determines that ignition is expected to be delayed and then selects a special mode to control the delay of the ignition. The ECU increase a target value of an energy input amount. This enables the delay of ignition resulting from a short extension of the path length to be minimized. The ignition apparatus equipped with the second circuit to continue the discharge of sparks is, thus, capable of reducing a variation in ignition without the need for uniformly increasing the energy input amount.

Abstract: A glow plug of a vehicle preventing an interference with an injected fuel includes a preheating rod having one end protruding to the combustion chamber to selectively preheat the combustion chamber; a bellows pipe enclosing the preheating rod to maintain an air-tightness of an area where the preheating rod is inserted to the combustion chamber; a piezo element selectively pulling or pushing another end of the preheating rod; and a controller controlling a deformation of the piezo element and the preheating of the combustion chamber through the preheating rod.

Abstract: A ship screw, pump screw or turbine screw for use under water or another liquid, comprising a front side and a rear side, wherein water or another liquid is forced from the front side to the rear side in use, and comprising a hub and at least two blades extending from said hub, wherein the blades are substantially helical/spiral shaped, their effective surface area increasing from the front side toward the rear side.

Abstract: This invention has to do with generating electricity by converting kinetic energy embedded in the water in motion such as ocean waves, or river flow, or wind pressure into rotational energy which is to be used to rotate the electricity generator spin axis to generate electricity. To achieve this goal, Moving Window Frame with multiple Vertical Windows and with or without a Horizontal Window is invented.

Abstract: A parametric excitation dynamic model is used for a three degrees-of-freedom (3-DOF) wave energy converter. Since the heave motion is uncoupled from the pitch and surge modes, the pitch-surge equations of motion can be treated as a linear time varying system, or a linear system with parametric excitation. In such case the parametric exciting frequency can be tuned to twice the natural frequency of the system for higher energy harvesting. A parametric excited 3-DOF wave energy converter can harvest more power, for both regular and irregular waves, compared to the linear 3-DOF. For example, in a Bretschneider wave, the harvested energy in the three modes is about 3.8 times the energy harvested in the heave mode alone; while the same device produces about 3.1 times the heave mode energy when using a linear 3-DOF model.

Abstract: A negative-pressure wave generator has a flow-driven assembly and a power-generating assembly disposed in the sea. The flow-driven assembly has multiple Venturi tubes connected to a power generating culvert of the power-generating assembly. The power generating culvert has a generator assembly. When sea water passes, the Venturi tubes generate negative pressure to make the water flow into the flow-driven assembly from the power generating culvert. A large pressure difference is formed between outside sea water out of a turbine disposed in a front end and a chamber disposed in a rear end, and the pressure difference drives the turbine to drive the generator assembly. The transferring efficiency is high and the water in all the flow channels is in low pressure to prevent the water pipes from burst and leakage. The negative-pressure wave generator is simple in structure and solid, lowering the maintenance cost.

Abstract: A Tidal Electricity Generator device and system providing a simple and effective way to generate electricity by harnessing tidal motion. The device has no parts to churn up the water, and does not actively force water through blades or screens. The device works passively to extract energy from the water by capturing the buoyancy of a bobber which rises and falls with the tides and/or gravity. Thus the kinetic energy of the tides is converted into mechanical energy which can then be transferred through a series of gears and other components to power an electric generator or other electric power grid. With this system, there is nothing to harm the environment or any sea life.

Abstract: The method allows stabilizing the rotation speed of a hydraulic machine with S-characteristics. It is implemented by means of a control loop feedback system having a controller for calculating an orientation to affect guide vanes of the machine. It includes steps of calculating a set of internal states associated with the operating point of the machine, establishing a linearized transfer function in function of the set of internal states, calculating characteristics parameters of the controller in function of the established transfer function so that the control loop feedback system is stable, measuring the rotation speed of the hydraulic machine, comparing the measured rotation speed with a target rotation speed, and adjusting the orientation affected to the guide vanes so as to reduce the speed difference between the calculated rotation speed and the target rotation speed.

Abstract: An apparatus powered by piston buoyancy is provided to generate rotary power by utilizing the effects of buoyancy and includes a tank containing a volume of liquid below a liquid level. A crankshaft is provided and is rotatably mounted to the tank above the liquid level. The crankshaft includes a rotatable main shaft. A hollow piston is disposed within the liquid in the tank and is provided having an interior cavity, an open bottom and one or more movable trap doors located at the top of the piston. A piston rod connects the hollow piston to a section of the crankshaft offset from a longitudinal axis of the main shaft. A gas supply system is provided having an outlet positioned beneath the open bottom end of the piston to supply gas to the interior cavity of the hollow piston and cause the piston to move upward and rotate the crankshaft.

Abstract: A mountable wing tip device (102) for mounting on a rotor blade of a wind turbine is disclosed which comprises a forward extremity (106) and at least two rearward extremities (108A, 108B, 112), wherein the forward extremity (106) and the at least two rearward extremities (108A, 108B, 112) are triangularly arranged, a leading edge region extending between the forward extremity (106) and the at least two rearward extremities (108A, 108B, 112), and a trailing edge region extending between the rearward extremities (108A, 108B, 112), a root region (113) at which the wing tip device (102) is mountable on an end of the rotor blade, wherein the root region (113) is positioned between the leading edge region and the trailing edge region.

Abstract: A wind turbine for a wind power generator includes: a center shaft arranged in a vertical direction; a plurality of horizontal arms attached in a radial manner to the center shaft; and a plurality of blades each arranged on an outer end of each of the plurality of horizontal arms so as to stand in an upright position, the plurality of blades each having a streamlined shape, in horizontal cross-section, including a 45±10% front side and a rear side, of which the rear side defines a convex arc-shaped outer-side surface and a concave arc-shaped center-shaft-side surface in a continuously closed manner, and a blade thickness across the convex arc-shaped outer-side surface and the concave arc-shaped center-shaft-side surface decreases gradually from a full dimension, in a region from a center-shaft-side point of inflection in blade thickness to a rear end of each of the plurality of blades.

Abstract: The present disclosure is directed to a system for determining a torque exerted on a shaft of a wind turbine. The system includes a gearbox coupled to the shaft. The gearbox includes a first arm and a second arm. First and second fluid dampers respectively couple to the first and second arms of the gearbox. A first fluid conduit fluidly couples the first and second fluid dampers. A first pressure sensor is in operative association with the first fluid conduit to detect a fluid pressure of fluid within the first fluid conduit. A controller communicatively couples to the first pressure sensor. The controller is configured to determine the torque exerted on the shaft based on signals received from the first pressure sensor.

Abstract: The present invention relates to a method for operating a wind power plant in a wake situation, said wind power plant being connected to a power grid, the method comprising the steps of operating the wind power plant in a predetermined power mode of operation, terminating said predetermined power mode of operation, and increasing power generation of the wind power plant to a power level that exceeds an optimized wake power level of the wind power plant, and injecting the increased amount of power into the power grid as a power boost. Thus, the present invention is capable of generating a power boost to an associated power grid, said power boost exceeding the power level normally being available in a wake situation. The present invention further relates to a system for carrying out the method.

Abstract: The present invention relates to a method and apparatus for controlling a wind turbine. The method includes: dividing a plurality of wind turbines into at least one group based on a similarity in status information of the plurality of wind turbines; in response to having detected a fault in a first wind turbine of the plurality of wind turbines, searching a group to which the first wind turbine belongs for a second wind turbine matching status information of the first wind turbine; and controlling the first wind turbine based on parameters from the second wind turbine.

Abstract: A wind turbine for generating electricity having a turbine assembly mounted on an inner support positioned within an aerodynamic fairing. The turbine assembly has an electrical generator positioned on the inner support and having a rotor shaft rotatable by a rotor blade. The aerodynamic fairing reduces the drag and wake created by the inner support.

Abstract: The invention relates to a method for determining dynamic parameters associated with damping properties of a wind turbine. The method involves active excitation of tower oscillations by adjusting the pitch or rotor torque. After the active excitation, the parameters can be determined from the passive decay of the excited oscillations. Alternatively, the oscillations can be actively damped, so that the parameters can be determined from the active decay of the excited oscillations. The method for promoting oscillations may be triggered in response to different events or in response to predetermined times for determining the actual dynamic parameters.

Abstract: A wind turbine including a generator with a stator and a rotor, a cooling arrangement, a wind turbine brake including a brake disk and a caliper with brake pads is provided. An air duct with a filter is located near the brake pads of the caliper. During the operation of the cooling arrangement, a part of the air flow is guided via the brake pads. The brake dust produced by the brake pads during operation of the brake will be reduced by the filter of the air duct.

Abstract: Evaporation-driven engines are disclosed herein. An example engine can include a water source having a high humidity zone proximate the surface of the water source, a supporting structure, and a hygroscopic material disposed on the supporting structure and configured to generate mechanical force in response to a changing relative humidity. The hygroscopic material can be repeatedly exposed to the high humidity zone and removed from the high humidity zone thereby causing the hygroscopic material to generate mechanical force.

Abstract: A control system comprises sources of supply, in terms of power and in terms of control signals, capable of equally piloting each of the electric thrusters and further comprises a switching device capable of linking any one of the sources of supply to any one of the electric thrusters. The switching device comprises a rotary main roller divided into a number of angular segments comprising input and output conductive tracks and pre-wired electrical networks linking the input conductive tracks to the output conductive tracks of each angular segment, the pre-wired electrical networks associated with the different angular segments all being different and dedicated to different configurations for the piloting of the electric thrusters by the sources of supply.

Abstract: An injection system includes a reservoir for containing liquid, and a gating plate having a circular array of gating plate apertures. The injection system additionally includes a faceplate positioned adjacent to the gating plate and having a circular array of faceplate orifices. The injection system also has a motor to rotate the gating plate, and a controller to control the motor for rotating the gating plate into an aligned clocking orientation in which the gating plate apertures and the faceplate orifices are aligned to initiate the formation of a cylindrical array of liquid jets, and rotate the gating plate into a non-aligned clocking orientation terminate formation of the liquid jets after a predetermined discrete quantity of the liquid is injected.

Abstract: A device for choking a fluid flow includes a pot-like base body, in the base of which a first passage opening is arranged, and a closing body guided axially moveably in the pot-like base body against a spring force of a spring element and having a second passage opening that forms a static choke point with a predefined fixed opening cross section. The closing body in combination with the spring element and the first passage opening forms a dynamic choke point with a dynamic opening cross section that is variably adjustable depending on a pressure difference.

Abstract: A drive mechanism module for use in a reciprocating pump converts rotational movement of a drive shaft to reciprocating movement of a reciprocating pump component transversely to the drive shaft. The drive mechanism module includes a connection member for attachment to the reciprocating pump component, a translating member that drives movement of the connection member in a first transverse direction while reciprocatingly translating in a second transverse direction relative to the connection member, a rotating member that rotates eccentrically with the drive shaft, and a rotary bearing assembly that permits rotation of the rotating member relative to the translating member while driving transverse movement of the translating member. The drive mechanism module may define a bearing fluid path for creating a hydrostatic or hydrodynamic fluid bearing at the interface of the connection member and the translating member.

Abstract: A beverage dispenser includes a dispenser housing having a first inlet, a piston being disposed in the dispenser housing, with the piston having a chamber extending through the piston, where the piston is movable in the dispenser housing between an open position and a closed position. The first inlet is in fluid communication with the chamber when in the open position. The first inlet is blocked from fluid communication with the chamber when in the closed position.

Abstract: Provided herein is a portable pump on a class 3-5 operable pickup truck rolling chassis with engine and transmission components for pumping liquid and/or slurried construction material, such as concrete, comprising a hydraulic pumping unit operably connected to a piston operated unit for charging first and second charging units with said construction material and for pumping said material therefrom where desired, wherein said hydraulic pumping unit is manually and/or remotely controlled by a PTO function of the pickup truck chassis engine, and wherein said pickup chassis includes first and second drive shafts mounted on opposite sides of a gearbox in connection with said PTO function.

Abstract: A pumping system includes a pump array of multiple pump-engine assemblies. Each pump-engine assembly comprises a pump and a gas turbine engine driving the pump. A manifold is coupled to the pumps. A master controller is coupled to each of the pump-engine assemblies either directly or via one or more intermediate controllers. The master controller and any intermediate controllers are collectively programmed to respond to user input including a desired hydraulic output at the manifold by automatically calculating and applying inputs to the individual pump-engine assemblies to provide the desired hydraulic output.

Abstract: A compressor includes a discharge conduit that extends between a discharge valve and a hermetic shell within the hermetic shell. A sealing connection assembly includes a housing mounted to one of the discharge valve and the hermetic shell. An inner surface of the housing has a tapered portion that contracts to a sealing edge. An end portion of the discharge conduit is positioned within the passage of the housing such that an outer surface of the discharge conduit is positioned on and contacts the inner surface of the housing at the sealing edge.

Abstract: A pump cassette is disclosed. The pump cassette includes a housing having at least, one fluid inlet line and at least one fluid outlet line. The cassette also includes at least one reciprocating pressure displacement membrane pump within the housing. The pressure pump pumps a fluid from the fluid inlet line to the fluid outlet line. A hollow spike is also included on the housing as well as at least one metering pump The metering pump is fluidly connected to the hollow spike on the housing and to a metering pump fluid line. The metering pump fluid line is fluidly connected to the fluid outlet line.

Abstract: A dual-head, pulseless peristaltic-type pump comprises a pump housing, cover, two compressible tube chambers and two sets of rotatable occluding members. An off-center drive axis driven by motor or other rotational mechanism rotate inner large diameter disk. Balls or rollers between inner disk rotate in one direction from center drive axis where the outer ring is stationary and occludes the tube by linear motion without friction between tube and outer ring. The linear roller occluding motion transfers liquid or slurry from inlet to outlet of tube. In one embodiment, two separate sets of occluding members are installed 180 degree opposite to each other such that pulsations are compensated for and canceled out.

Abstract: An eyeglass buffer protection device for using in a pair of glasses comprises a min body, which has a penetrating channel and comprises an inflatable cushion, an air pump, a switch element and a control unit. When the switch element is turned on, the switch element issues an enabling signal to the control unit and the control unit enables the air pump in response to the enabling signal. When the air pump is enabled, an ambient gas is transferred to the inflatable cushion, so that the inflatable cushion is inflated with the gas and the main body is expanded. By penetrating the at least one leg of the glasses into the penetrating channel of the main body, the at least one leg is protected, and the main body fits closely with the ear of the user.

Abstract: Automated operation of well site pumping equipment, including generating a mathematical belief model for maintaining an interrelationship between flow rate achievable by a pump unit discharge pressure of the pump unit, and probability of achieving the flow rate at corresponding discharge pressure. Speed of the pump unit is controlled to achieve a target speed based on a flow rate set-point and the mathematical belief model and updating the mathematical belief model at least while the target speed is achieved. Updating the mathematical belief model may include increasing the probability of achieving the flow rate set-point when actual flow rate of the pump unit is not less than the flow rate set-point and decreasing the probability of achieving the flow rate set-point when the actual flow rate of the pump unit is less than the flow rate set-point.

Abstract: A mechanism for limiting vibration amplitudes in a pumping system includes a plurality of pendulum absorbers coupled with a carrier and each having a pivoting range. The pendulum absorbers each further include a first and a second contact surface that contacts an outer peripheral surface of the carrier at limit stop positions, and each having a shape that is conforming with a shape of the outer peripheral surface. The pumping system may be used for pumping liquid nitrogen.

Abstract: A valve clack is provided. The valve clack includes: a mounting column (11) having a plurality of air slots (111) for dispersing an airflow at least in a top surface of the mounting column (11); a plurality of blades (12) arranged outside the mounting column (11) in a circumferential direction of the mounting column (11), each blade (12) having a radial inner end connected to the mounting column (11) and elastically swingable with respect to the mounting column (11).

Abstract: A vane cell machine is provided comprising a housing having a stator bore with an outer limitation formed by a circumferential wall and two axial end faces (5), a rotor mounted rotatably in said stator bore, a plurality of vanes moveable in radial direction relative to said rotor and sliding along said circumferential wall, and sealing means (12) at least at one of said end faces (5), said sealing means (12) acting on said rotor in axial direction. Such a vane cell machine should have a simple construction. To this end said end face (5) is formed at an end plate (11) of said housing wherein said end plate (11) comprises a recess in which said sealing means (12) are rotated.

Abstract: A gear pump has a pump body, a pump cylinder connected with the pump body, a driving gear and a driven gear meshed with each other and disposed in the pump cylinder, and a motor driving the driving gear through a driving shaft. The pump cylinder is located between the pump body and the motor. The driving gear is mounted to or integrally formed with the driving shaft. A first bearing and a second bearing are disposed on respectively sides of the driving gear, one end of driving shaft is received in the first bearing, and the other end of the driving shaft extends through the second bearing and into the motor and forms a shaft of the motor.

Abstract: A compressor may include a first compression member, a second compression member, and a motor assembly. The second compression member is movable relative to the first compression member and cooperates with the first compression member to define a compression pocket therebetween. The motor assembly drives one of the first and second compression members relative to the other one of the first and second compression members. The motor assembly includes a stator and a rotor. The rotor is rotatable relative to the stator about a rotational axis. The stator surrounds the rotational axis. The rotor may include magnets that are arranged around the rotational axis. The magnets may be spaced apart from the stator in an axial direction that is parallel to the first rotational axis.

Abstract: An electric canned coolant pump includes a drive motor comprising a split case provided as a separating can which separates a wet chamber comprising a motor rotor from a dry chamber comprising a motor stator. The separating can comprises a separating can form-fit structure. A Hall sensor is arranged on the separating can. The Hall sensor detects a position of the motor rotor in the dry chamber. The Hall sensor comprises a sensor head and Hall sensor electric connecting lines. A positioning element comprises positioning element electric connecting lines which are connected with the corresponding Hall sensor electric connecting lines. The positioning element electric connecting lines comprise a connecting body comprising a connecting body form-fit structure. The connecting body is electrically insulating and holds the positioning element electric connecting lines. The separating can form-fit structure and the connecting body form-fit structure fix the connecting body on the separating can.

Abstract: A pumping system for at least one aquatic application includes a motor coupled to a pump and a controller in communication with the motor. The controller is adapted to determine a first motor speed of the motor, determine a reference power consumption using a reference flow rate and a curve of speed versus power consumption for the reference flow rate, and generate a difference value between the reference power consumption and a present power consumption. The controller drives the motor to reach a steady state condition at a second motor speed based on the difference value.