Abstract: A magnetic bearing device includes first and second radial electromagnets supporting a rotor shaft in a contactless manner in first and second radial directions. A controller controls each of a first excitation amplifier and a second excitation amplifier based on a result of demodulation by each of a first demodulation section and a second demodulation section. The phase of a second carrier signal differs by (?/2+?) radian from the phase of a first carrier signal. A first demodulation section samples a detection signal of a first current sensor at sampling timing shifted by a phase ? from timing at which a first carrier signal becomes a peak, and a second demodulation section samples the detection signal of a second current sensor at sampling timing shifted by a phase (??) from timing at which the second carrier signal becomes a peak.

Abstract: AC and DC brushless motor for the fan, comprising a brushless motor; and an active power adjustment mechanism, disposed within the brushless motor and comprising an EMI filtering and rectifying unit, a prior driving unit connected to the EMI filtering and rectifying unit, a motor driving unit connected to the brushless motor, a constant current unit connected to the EMI filtering and rectifying unit and the prior driving unit, a protective compensation unit connected to the prior driving unit and the constant current unit, a motor controlling unit connected to the motor driving unit, and a sensing unit connected to the motor controlling unit.

Abstract: The embodiments herein provide an apparatus and method for cancelling signal noise. According to one embodiment, an apparatus for cancelling signal noise has a sensor or receiver to capture the undesirable signals. A transducer converts the energy of the captured signals and modulates the captured undesirable signals. A signal inverting circuit is connected to the transducer to generate the inverse of the captured undesirable signals by inverting the amplitude of the undesirable signal while maintain the frequency at the same level. The generated inverse of the undesirable signal transmitted by a transmitter is received by a receiver and output through a speaker so that the output inverse of the undesirable signal is combined with the undesirable signal to produce a desired signal environment.

Abstract: A brushless motor for an electric power steering device that assists a steering operation includes: a stator having a plurality of winding sets for a plurality of systems respectively; and a rotator having a ferrite magnet. In the motor, a maximum current flowing without any demagnetization at high temperature is large. Hence, the torque of the motor is easily ensured at high temperature. In particular, when a failure occurs in one system, it is easy to ensure the torque of the normal system even at high temperature.

Abstract: A method is provided that includes installing a compressor in a refrigeration system and determining a condenser temperature difference using processing circuitry. The method also includes checking for an overcharge condition or a condenser fan blockage condition when the condenser temperature difference is greater than a high condenser temperature difference value. The method also includes determining a discharge superheat temperature using the processing circuitry and checking for the overcharge condition or the condenser fan blockage condition when the condenser temperature difference is less than the high condenser temperature difference value and the discharge superheat temperature is less than a low discharge superheat temperature value.

Abstract: Both a catalyst feed system and a method are provided for providing a flow, of a mud-like catalyst slurry into a polyolefin reactor. The system includes a pressurized reservoir of the catalyst having an outlet, and a progressive cavity pump including a stator and a rotor. The pump stator has an inlet connected to the reservoir outlet, and an outlet leading to the polyolefin reactor. In operation, the reservoir is first pressurized to a level a little higher than the pressure of the reactor. The outlet of the reservoir is opened and the progressive cavity pump is actuated. The pressure drop generated across the catalyst slurry contained in the reservoir by the pump causes the slurry diluent to flow between the interstices of the particles of catalyst. The thick, mud-like catalyst slurry is quickly transformed into a much less viscous, syrup-like slurry that flows from the reservoir outlet to the inlet of the pump stator.

Abstract: Compressors and methods for determining optimal parking positions for compressor pistons are provided. A method includes performing a current value evaluation for an initial time during operation of a motor of the compressor. Performing the current value evaluation includes measuring a motor current value at the time and comparing the motor current value to an existing optimal parking current value. Performing the current value evaluation further includes modifying the existing optimal parking current value to the motor current value when the motor current value exceeds or is equal to the existing optimal parking current value.

Abstract: Modular motor apparatuses, systems and methods are disclosed. Certain embodiments comprise a motor core and driver module a power supply module, and an external interface module. Families of these modules may utilize a standardized communication protocol to enhance flexibility, upgradeability, and serviceability in the configuration of the motor apparatus. Certain embodiments comprise a power sharing system in which a power supply module serves two or more motor core and driver modules. Certain embodiments comprise a motor performance configuration module including an integrated or remote user interface. The user interface is configured to allow a high reliability graphical performance configuration and scaling of motor performance without the use of a computer on the motor.

Abstract: A pump system including a motor, a user-interface, and a controller. The user-interface having a single bar graph comprised of light-emitting diodes to provide visual feedback to an operator. The bar graph is used for programming purposes and for providing a motor speed and run duration status to the operator.

Abstract: A method for controlling air volume output by a motor. The method includes: 1) establishing functional relation formulas for air volume in a low torque interval and a high torque interval; 2) inputting a target air volume into a microprocessor control unit; 3) starting a motor under a torque to enable the motor to reach a steady state; 4) acquiring an adjustment coefficient under the torque, and calculating the air volume; 5) comparing the target air volume with the calculated air volume; 6) re-recording a steady rotational speed after the motor reaches a new steady state under an increased or reduced torque, and recalculating the air volume in the new steady state; and 7) repeating steps 5) and 6) to adjust the torque until the calculated air volume is equal or equivalent to the target air volume.

Abstract: Embodiments of the systems and methods disclosed herein utilize a brushless DC motor (BLDCM) to drive a single-stage or a multi-stage pump in a pumping system for real time, smooth motion, and extremely precise and repeatable position control over fluid movements and dispense amounts, useful in semiconductor manufacturing. The BLDCM may employ a position sensor for real time position feedback to a processor executing a custom field-oriented control scheme. Embodiments of the invention can reduce heat generation without undesirably compromising the precise position control of the dispense pump by increasing and decreasing, via a custom control scheme, the operating frequency of the BLDCM according to the criticality of the underlying function(s). The control scheme can run the BLDCM at very low speeds while maintaining a constant velocity, which enables the pumping system to operate in a wide range of speeds with minimal variation, substantially increasing dispense performance and operation capabilities.

Abstract: A method for preventing damage to a downhole pump impeller of a downhole pump includes setting a rotatable part of a downhole pump to a selected depth, monitoring the depth of the rotatable part, determining that the depth of the rotatable part has significantly changed, and taking a corrective action to return the depth of the rotatable part to said selected depth in order to prevent damage to an impeller that is liable to be caused by a change in depth of the rotatable part. The downhole pump further has a line shaft, an impeller engaged with the line shaft for pressurizing fluid to be extracted from a well, and monitoring apparatus for monitoring the depth of a distal end of the line shaft in order to prevent damage to the impeller that is liable to be caused by a change in depth of the distal end.

Abstract: There is provided a system and method for driving AC powered subsea loads. Disclosed embodiments include a system having a rectifier and DC filter configured to be located at a surface vessel and configured to convert AC power supplied by a surface AC power source into DC power. The DC power is transmitted from the surface vessel to an inverter configured to be located remotely from the surface vessel at a subsea location. The subsea inverter converts the transmitted DC power back into AC power, which may then be utilized for driving one or more AC powered subsea loads.

Abstract: Disclosed is a high volume low speed (HVLS) fan that is designed to circulate air in large buildings for cooling, heating, and ventilation. A fan with a diameter between 8 to 24 feet consisting of a plurality of blades, with each in the shape of a tapered airfoil, is driven by a direct drive transverse flux electric motor to produce a very large slowly moving column of air. The HVLS system preferably includes motion and angular shutdown, voltage recognition, blade size recognition and data logging for recording the last 100 or so hours of operation to facilitate warranty applicability and assist in trouble shooting as well as software updates and programming via Bluetooth and internet keypad.

Abstract: A method and system for pumping unit with an elastic rod system is applied to maximize fluid production. The maximum stroke of the pump and the shortest cycle time are calculated based on all static and dynamic properties of downhole and surface components without a limitation to angular speed of the prime mover. Limitations of structural and fatigue strength are incorporated into the optimization calculation to ensure safe operation while maximizing pumped volume and minimizing energy consumption. Calculated optimal prime mover speed is applied to the sucker rod pump by means of beam pumping, long stroke or hydraulic pumping unit by controlling velocity, acceleration and torque of the electric prime mover or by controlling pressure and flow rate in hydraulically actuated sucker rod pumping system.

Abstract: A dual speed pump controller includes a motor controller for operating a dual speed motor. The controller includes an operating speed circuit for operating the motor in one of a first speed or a second speed, the first speed being greater than the second speed; an event circuit for operating the motor at the first speed before a predetermined event and operating the pump at the second speed after the predetermined event.

Abstract: A method of controlling a fluid pump to supply lubricating fluid to a plurality of fluid requiring components in a hybrid vehicle powertrain includes selecting a component-required flow rate for each respective component using a determined operating speed and torque for that respective component. Once the each component-required flow rate is selected, the system flow rate is set to the maximum component-required flow rate of the plurality of component-required flow rates. The fluid pump is then commanded to supply fluid to each of the plurality of fluid requiring components at the system flow rate.

Abstract: A system includes a sump, a pump having a steady-state speed, a fluid component that receives the fluid from the fluid pump, and a controller. The controller detects a soak condition of the system in which the pump load is low as fluid is moved into vacated fluid passages. The steady-state speed of the pump is temporarily increased by adding a calibrated overspeed value to the steady-state speed, for a calibrated duration. The controller reduces the pump speed to the steady-state speed after the calibrated duration has elapsed. A method includes detecting the soak condition and temporarily increasing the steady-state speed via the controller by adding the calibrated overspeed value to the steady-state speed, for a calibrated duration, when the soak condition is detected. A control system includes a processor and storage medium having instructions embodying the method, with detection of the soak condition provided via measurement of fluid temperature.

Abstract: The design of a high efficiency, variable performance vaneaxial fan, requires the utilization of typical fan and single stage compressor design methodologies. To be able to replace multiple fans, the variable vaneaxial fan design must be capable of operation at several different flow rates and total pressures. These operation points can be met by varying motor revolutions per minute (RPM) or geometric parameters such as the hub diameter, tip diameter, as well as blade geometry including number of blades, pitch, spacing, and length. An ideal design with variable performance can replace a family of current fan designs by providing the capability for efficient operation over a range of flow rates and total pressures. This level of variability would not only allow the fan to respond to changing environmental conditions but also to be fit into systems with different characteristics.

Abstract: A fan motor controller for a turbine engine comprises a component mounting base and a plurality of fan controller components mounted to the component mounting base. The component mounting base comprises a plurality of sections that are configured to extend circumferentially around a fan inner housing.

Abstract: A motor controller, including: a supporting frame, a control circuit board, and a control box. The control box includes: a cavity, a base plate, and a plurality of fins. The control circuit board is disposed on the base plate in the cavity. The fins are disposed outside the cavity on an outer side surface of the base plate. Cooling ducts are formed between adjacent fins. The control box is fixed on the supporting frame.

Abstract: A blower unit controller and an HVAC system are disclosed herein. In one embodiment, the blower unit controller includes: (1) an input configured to receive motor operating parameters, (2) an output configured to provide a motor speed control signal to an inverter, (3) a memory configured to store a mathematical model of airflow produced by a blower motor, the mathematical model being configured to relate a motor speed to the motor operating parameters and (4) a processor configured to produce the speed control signal based on the mathematical model.

Abstract: A system includes a motor, an inverter bridge, a voltage detection circuit, and a controller. The motor has a stator and a rotor. The inverter bridge is configured to provide a voltage to the stator, and includes a first switch connected in a series-type relationship with a second switch, a first diode coupled across the first switch, and a second diode coupled across the second switch. The voltage detection circuit is configured to detect a back EMF voltage in the winding. The controller is configured to control the first switch and the second switch to drive the motor, and to receive an indication of the back EMF voltage in the winding from the voltage detection circuit. The controller is also configured to determine a fault has occurred, and to drive one of the first switch and the second switch when a fault has occurred.

Abstract: A vane compressor includes a cylinder block, a cylinder chamber having an ellipsoidal inner wall, a rotor whose outer circumferential surface is provided with vane slots formed thereon, a drive source for the rotor, and vanes housed in the vane slots, respectively. The rotor is rotated by the drive source while the vanes are protruded from the vane slots by backpressure generated in backpressure spaces in the vane slots to contact end edges of the vanes with the inner wall of the cylinder chamber. The compressor further comprises a stop mechanism that makes the rotor stopped at a predetermined rotational position where a difference between a total volume of the backpressure spaces when operated and a total volume of the backpressure spaces when stopped becomes minimum. According to the compressor, chattering can be prevented without extra workings on the vanes or the rotor and without providing extra parts.

Abstract: A hydraulic cylinder assembly for a fluid pump including a cylinder, a bearing attached to an approximate first end of the cylinder, a rod slideably mounted within the bearing, and a piston located about an end of the rod in the cylinder opposite the bearing. A central axis of the rod is offset from, and parallel to, a centerline of the cylinder to impede a rotation of the piston about the rod. The hydraulic cylinder assembly further including a hydraulic pump fluidly connected to the cylinder, the pump configured to provide a hydraulic pressure to the cylinder during an up-stroke of the piston and rod and the pump further configured to generate electricity on the down-stroke of the piston and rod.

Abstract: A converterless motor-driven pump system includes an off-grid prime mover. The off-grid prime mover has a rotational driveshaft and operates in response to a throttle control command to control a rotation speed of the rotational driveshaft. An electric power generator is driven by the off-grid prime mover to generate AC power. A variable speed induction motor is directly powered by the electric power generator. A pump that may be submersible is driven by the at least one variable speed induction motor. A system controller that may be local or remote is programmed to generate the throttle control command in response to one or more pump operating characteristics such that the off-grid prime mover, the electric power generator, and the variable speed induction motor together operate to regulate a pressure at the inlet of the electric pump.

Abstract: A system includes a motor coupled to an energy source and coupled to a hoist pump. During one mode of use or operation, the motor cars receive electricity from the energy source and provide mechanical power to the hoist pump. A method includes directing a motor to mechanically couple to the hoist pump, and directing electrical power to flow from an energy source to the motor, and thereby to control the speed of hoist activity.

Abstract: A motor controller comprises: a rotation angle estimation unit for estimating and computing a rotation angle of a motor repeatedly based on the current and voltage of the motor without using a motor rotation angle detector; a speed calculation unit for calculating the period of the signal waveform of the rotation angle that is repeatedly estimated and calculated by the rotation angle estimation unit and for calculating an actual rotational speed of the motor based on the period; a drive signal generating unit for generating a drive signal to drive and control the motor based on at least a deviation between the actual rotational speed and a target rotational speed and the rotation angle; and a switching circuit that is switched based on the drive signal to provide drive power to the motor.

Abstract: A cryopump includes: a cryopump chamber having an inlet port through which a gas to be pumped is introduced; a refrigerator provided with a second cooling stage provided in the cryopump chamber; an intermediate member thermally coupled to the second cooling stage; and a cryopanel having a connecting part connected to the intermediate member at a position farther from the inlet port in the direction in which the gas is introduced than the second cooling stage, and extending from the connecting part toward the inlet port. For example, a cryopump having a suspended panel structure is provided.

Abstract: An apparatus for controlling a compressor is provided. When grounding the apparatus for controlling a compressor, an analog circuit ground and a digital circuit ground may be insulated from each other to protect the apparatus. A ground of an analog circuit driven by commercial alternating current (AC) power, and a ground of a digital circuit driven by a voltage which has been converted from commercial AC power, may also be insulated from each other by a simple circuit device to protect a controller inside the digital circuit.

Abstract: Apparatus is provided featuring a switch-mode power supply (SMPS) having a power circuit component in combination with a SMPS controller. The power circuit component may be configured to provide power to a pump that provides fluid from a container to some other device, including an appliance. The SMPS controller may be configured to receive signaling containing information about at least one control parameter selected from a group including a pressure at an outlet of the pump, a fluid level in the container and the temperature of a motor of the pump, and also may be configured to shut off the power provided to the pump based at least partly on the signaling received so that the power circuit component substantially does not draw power and heat up when the pump is shut off.

Abstract: A sensor system for sensing liquid level in a bilge, for use in automatic bilge pump actuation. First and second field effect sensors are potted or sealed within a container or the bilge wall and are aligned in a vertical array and each comprise a substantially planar pattern of “electrodes” or conductive traces disposed on a printed circuit board (PCB) along with integrated circuits used to create a loop or arc-shaped electric field. As bilge liquid rises to the proximity or level of the field effect sensors, a change in the arc-shaped electric field is sensed and, in response, a bilge pump is automatically actuated to pump liquid out of the bilge. Optionally, the pump control can be programmed by use of a microprocessor to permit control of on-off timing and prevent undesirable effects of “sloshing.

Abstract: The fluid flow of a fluid displacement device (100) provided with an electric motor (120) may be set on the basis of a power and control unit (90). Thereto, a power circuit generally comprising an inverter (30), such as a frequency inverter, drives the electric motor (110), particularly with a driving voltage (D1). Voltage and current (A1, A2) in the electric motor (110) are sensed sensorless. Torque and rotation speed of the electric motor (110) are derived from said sensed voltage and current (A1, A2). A fluid flow of the fluid displacement device (110) is estimated in an estimator (15) based on said torque and rotation speed of the electric motor (120) and at least some fluid displacement device characteristics stored in a memory.

Abstract: The air-conditioning apparatus includes a coolant circuit configured by sequentially connecting a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger; a motor that operates a compressor mechanism disposed inside the compressor; an inverter for driving the motor; and a control unit that controls the inverter. The control unit includes a liquefaction detecting unit that detects coolant liquefaction in the compressor; includes a first PWM signal generating unit that generates an inverter control signal for driving the motor; includes a second PWM signal generating unit that generates an inverter control signal for making the motor perform a preheating operation; and includes a switching unit that performs switching in such a way that the first PWM signal generating unit or the second PWM signal generating unit outputs the corresponding inverter control signal to the inverter.

Abstract: A pumping system for moving water of a swimming pool includes a water pump, a variable speed motor, and an arrangement for controlling the variable speed motor. The pumping system further includes an auxiliary device operably connected to the arrangement for controlling, and an arrangement for providing two-way communication between the arrangement for controlling and the auxiliary device. The arrangement for controlling is capable of receiving a parameter from the auxiliary device through the arrangement for providing two-way communication. In one example, the arrangement for controlling is capable of independently controlling the variable speed motor without receipt of a parameter from the auxiliary device. In addition or alternatively, the arrangement for controlling is operable to selectively alter operation of the motor based upon the parameter.

Abstract: A fan comprises a hub, fan blades, and inserts. The hub comprises outwardly extending mounting tabs that lie along a common horizontal plane. The fan blades are hollow, such that each mounting tab is inserted in the hollow interior of a corresponding fan blade. Each insert is positioned in the hollow interior of each fan blade, between each mounting tab of the hub and the interior surface of the corresponding fan blade. Each insert is configured to position and maintain the chord line of each corresponding fan blade at an oblique angle relative to the horizontal plane of the hub. A kit may include several insert sets to choose from to provide adjustable angle of attack. A fan control system includes a dimmer switch and a control module, which allows the dimmer switch to be used to infinitely adjust the speed of a fan motor within a range.

Abstract: A device for pumping blood, includes a housing having a distal end adapted to be coupled to a catheter, a proximal end having an outlet, and a tubular body extending between the distal and proximal ends along an axis. A rotor is rotatably disposed within the housing. A first magnetic bearing is operative to levitate the rotor along the axis within the housing. A second magnetic bearing controls a rotational frequency of the rotor. A third magnetic bearing controls a radial position of the rotor.

Abstract: A hydraulic pump arrangement of a portable hydraulic tool operates by an autonomous power supply or is releasably connected to the hydraulic tool by a hose and driven by an electrical power source. A load-dependent control of the hydraulic pump switches between a loaded state and a non-loaded state. A higher electrical power supply is implemented for the loaded state and a lower electrical power supply is implemented for the non-loaded state. To provide energy savings and problem-free operation even in different system pressure conditions, a method fixes a control variable for the load-dependent control that is dependent on work being performed by the hydraulic pump motor. A first threshold value at which switching from the non-loaded state to the loaded state takes place and a second threshold value at which switching from the loaded state to the non-loaded state takes place are assigned to the control variable.

Abstract: The invention relates to a method for lubricating a transmission of a motor vehicle, particularly a power divider, wherein the oil is conveyed by an oil pump from an oil sump to components of the transmission. The amount of oil conveyed is set as a function of the predetermined parameters. The conveyed amount of oil is controlled in that the oil pump is operated intermittently, e.g. is switched on and off repeatedly. The invention further describes a device for carrying out the method.

Abstract: A circulation pump assembly (1) includes an electric drive motor (6) and a control device (10, 12) for the control of the drive motor (6). The control device (12) includes a communication interface (13) designed for connection to at least one external sensor (38, 50, 52, 54, 56) and/or at least one further assembly (40, 42, 44, 46, 48, 58, 62, 64, 66, 68) to be controlled by the control device, as well as to a heating installation and/or air conditioning installation with such a circulation pump assembly (1).

Abstract: The invention relates to a method for controlling a pump arrangement comprising a pump (2) having a motor (7) and a control unit (6), said motor (7), when the pump (2) is in an active state and the motor (7) is driven in a first direction, being associated with a load factor that corresponds to an operating condition of the pump arrangement; the pump arrangement also comprising means for monitoring at least one operating parameter from which the load factor of the motor (7) can be derived.

Abstract: A fan control system. The fan control system has a programmable microcontroller to receive an input signal and a rotation speed signal corresponding to the actual rotation speed of the fan motor, determining an output signal according to the input signal and the rotation speed signal, and outputting the output signal; and a fan-driving unit to receive the output signal and adjusting the rotation speed for driving the fan motor according to the output signal. The rotation speed is in a relation of a multi-stage function to the input signal.

Abstract: A pump control system includes a controller coupled to first and second pressure sensors. The sensors couple serial pressure related information to the controller. The controller can evaluate respective liquid levels, in response to received pressure related information from the sensors. A current sensor coupled to the controller can provide signals indicative of operation of one or more pumps coupled to the controller. The controller includes circuits to detect the presence of predetermined faults and to emit an audible fault indicator in response thereto.

Abstract: A method for collecting condensate inside an apparatus, including: providing a condensate collection system with bottom and top collection tanks; a condensate discharge pump to displace liquid from the bottom collection tank to the top collection tank; and an overflow system which displaces the liquid contained in the top collection tank that exceeds an overflow level into the bottom collection tank; collecting a condensed liquid in the bottom collection tank; actuating the condensate discharge pump to displace the condensed liquid from the bottom collection tank into the top collection tank; detecting a low load condition of the condensate discharge pump, actuation of the condensate discharge pump being interrupted upon detection of the low load condition; the actuating time (T2) of the condensate discharge pump, with signalling of a full condition of the condensate collection system when this actuating time (T2) is equal or larger than a maximum time (T2lim).

Abstract: Dosing device (100) for dispensing a specified vol? ume of liquid, comprising an electromagnet (1 11) and being adapted to hold a pump (1 12) with a magnetisable pumping member (1 10) displaceable under the action of the electromagnet when the pump is held by the dosing device. The dosing device further comprises a portable voltage source (1 13) adapted to energize the electromagnet by repeated current pulses and to measure the current intensity at least once per pulse, thereby estimating the charge amount in each pulse, until a total charge amount corresponding to the speci? fied volume of liquid to be dispensed has been supplied. A method including pulse-wise activation of an electromagnet actuating a pump having a magnetisable pumping member is also disclosed.

Abstract: The present invention relates to a control device for a radiator fan, in particular for a radiator fan of a motor vehicle, having an external control device which is designed to generate a controlled variable for an electric motor of the radiator fan according to a first predefined setpoint value, and having an internal control device which is designed to control the motor current of the electric motor of the radiator fan according to a predefined first motor current maximum value if the controlled variable which is generated by the external control device assumes such a value that the motor current exceeds the predefined first motor current maximum value. The present invention also relates to a radiator fan arrangement and to a method for controlling a radiator fan.

Abstract: A pumping system featuring a pump chamber configured with a central portion having a tangential outlet, and configured with a tubular coupling end portion having inwardly flexible rim portions on one side; and a mounting base, having a circular portion with an inner circumferential rim configured to receive and engage the inwardly flexible rim portions of the tubular coupling portion of the pump chamber so as to be rotationally coupled to the pumping chamber so that the pumping chamber may be rotated 360° in relation to the mounting base.

Abstract: A method and apparatus for operating a pumping system includes the following: determining a motor operating parameter of a motor configured to drive a pump in a well; determining a pump operating parameter of the pump based on the motor operating parameter; operating the pump in a first mode to determine pump characteristics at a desired fluid level; generating first mode output data based on operation of the pump in the first mode; operating the pump in a second mode based on the first mode output data; determining an estimated fluid level in the well based on the motor operating parameter, the pump operating parameter and the first mode output data; and adjusting the pump speed based on the estimated fluid level in order to maintain a desired fluid level.

Abstract: A method and apparatus for a pump control system. One or more embodiments of the invention include a pump controller that can perform a self-calibrating procedure, can provide precise motor speed control, can provide a limp mode before shutting down the motor when system parameters are exceeded and/or fault conditions occur, can detect fault conditions, and can store fault conditions for later retrieval.

Abstract: An embodiment of method used to control operation of a screw compressor of a refrigeration system may include receiving status signals regarding operation of the screw compressor of the refrigeration system. The method may further include determining an operating point of the screw compressor based upon the received status signals, and selecting a torque profile for the screw compressor based upon the operating point. The method may also include driving the screw compressor per the selected torque profile. Refrigeration systems and compressor systems suitable for implementing the method are also presented.