Unico Corp.

Mark E Garlow

Thomas L Beck

Ronald G Peterson

William S Hammel

Michael A MacDonald

Michael D Dry

Theresa Smigura

Michael O Lucas

Robb G Anderson

Harry W Schulz

David R Seidl

Michael A Macdonald

There is disclosed an apparatus and method to reduce total harmonic distortion input into a 24-pulse autotransformer system and the autotransformer system itself. The 24-pulse autotransformer system is configured to receive an input of a first voltage and produce an output voltage of a second voltage. The system includes a pair of autotransformers coupled to an AC power source. One winding of each phase of the first autotransformer has a turn ratio to effect a decrease in the voltage across said winding over a symmetric voltage value and a second winding of each phase of the first autotransformer has a turn ratio to effect a decrease in the voltage across said winding over a symmetric voltage value, thereby reducing total harmonic distortion (THD) in the input current to the system without a zero sequence blocking transformer.

Autotransformer system reducing total harmonic distortion

A rod pump control system includes a parameter estimator that determines from motor data parameters relating to operation of the rod pump and/or downhole dynamometer card without the need for external instrumentation, such as down hole sensors, echo meters, flow sensors, etc. In one embodiment, instantaneous motor current and voltage together with pump parameters are used in determining rod position and load. The rod position and load are used to control the operation of the rod pump to optimize the operation of the pump. Also disclosed in a pump stroke amplifier that is capable of increasing pump stroke without changing the overall pumping speed, or in the alternative, maintaining the well output with decreased overall pumping speed.

Rod pump control system including parameter estimator

A system and method are provided for controlling the speed of a motor driving a load that is electrically connected to a generator driven by an engine, through use of a first control feedback loop configured to control the rotor flux of the motor by controlling the field excitation of the generator, and a second control feedback loop configured to control the speed of the motor by controlling the throttle position of the engine.

Induction motor torque control in a pumping system

An apparatus is provided for estimating and/or precluding stick-slip, or other oscillatory or resonant behavior, through use of a virtual transducer, which precludes the need for having sensors located adjacent to a driven element of the system, or adjacent contact surfaces at which the stick-slip relative motion may occur. Parameters measurable at a drive mechanism are utilized for controlling a system in a manner which precludes stick-slip, or other oscillatory or resonant behavior, of a driven element of the system. Relative motion between contacting surfaces in the driven element, prone to stick-slip behavior, is controlled after sufficient force is applied by the drive element to overcome static friction forces between the contacting surfaces and break them free from one another, relative motion between the surfaces is maintained at a high enough relative speed that the surfaces are precluded from contacting one another, so that stick-slip behavior is precluded.

Estimation and control of a resonant plant prone to stick-slip behavior

Presented is a harmonic regulator that regulates a plurality of individual harmonics in a system having periodic torque disturbances to commanded values, including zero. For each harmonic being regulated, a feedback signal having at least one harmonic component due to the harmonic being regulated is transformed from a source reference frame to a harmonic reference frame of the harmonic being regulated to form a qd feedback signal. The qd feedback signal is subtracted from the commanded value to form a qd signal and regulated. The regulated qd signal is transformed to a destination reference frame to form a compensation signal and the compensation signal is added to a control signal to form a qd control signal that drives each harmonic being regulated towards the commanded value.

Bus disturbance regulator

A method and apparatus are provided for estimating and/or precluding stick-slip, or other oscillatory or resonant behavior, through use of a virtual transducer, which precludes the need for having sensors located adjacent to a driven element of the system, or adjacent contact surfaces at which the stick-slip relative motion may occur. Parameters measurable at a drive mechanism are utilized for controlling a system in a manner which precludes stick-slip, or other oscillatory or resonant behavior, of the driven element. Relative motion between contacting surfaces in the driven element, prone to stick-slip behavior, is controlled such that, after sufficient force is applied by the drive element to overcome static friction forces between the contacting surfaces and break them free from one another, relative motion between the surfaces is maintained at a high enough relative speed that the surfaces are precluded from statically contacting one another, so that stick-slip behavior is precluded.

Harmonic disturbance regulator

A system for controlling operation of a progressing cavity pump to maintain the motor operating under power disturbance conditions. For a blackout condition, a backspin controller uses regenerative power to provide controlled deceleration of the pump, counteracting backspin and preventing backspinning freely. For a brownout condition, a power dip controller weakens the motor field to maximize pump production consistent with reduced input power availability. For a phase loss or voltage imbalance condition, a phase loss controller reduces motor power output to keep drive system output power at or below single phase capacity.

Method and system for improving pump efficiency and productivity under power disturbance conditions

A rod pump control system includes a parameter estimator that determines from motor data parameters relating to operation of the rod pump and/or downhole dynamometer card without the need for external instrumentation, such as down hole sensors, rod load sensors, flow sensors, acoustic fluid level sensors, etc. In one embodiment, instantaneous motor current and voltage together with pump parameters are used in determining rod position and load. The rod position and load are used to control the operation of the rod pump to optimize the operation of the pump. Also disclosed in a pump stroke amplifier that is capable of increasing pump stroke without changing the overall pumping speed, or in the alternative, maintaining the well output with decreased overall pumping speed.

Growing community of inventors

Kenosha, WI, United States of America

Mark E Garlow