KR20150088600A - Power consumption reduction apparatus for resource mining machine - Google Patents

Abstract

Disclosed is an apparatus for reducing power consumption for a resource mining machine. The apparatus for reducing power consumption comprises: a harmonic wave removing unit to reduce the harmonic wave substance of an input power supply to create a driving power supply applied to a motor to operate a resource mining machine; a reverser electromotive force absorbing unit to absorb at least a part of a reverse electromotive force generated when the resource mining machine enters into the underground and to add to a driving power supply; and a torque control unit to perform a proportionate differential and integral calculus for an error between a result of control of the torque of a motor and a set value and to control the torque of the motor. According to the present invention, the harmonic wave of the driving power supply supplied to a motor to drive a resource mining machine is reduced, and a part of minus power generated during a down stroke of the resource mining machine is absorbed and included in the supply power supply of the motor. As the unit process cycle can be maintained to be uniform by making the up stroke speed of the resource mining machine higher and the down stroke speed lower, the power consumption of the resource mining machine is reduced.

Description

Technical Field [0001] The present invention relates to a power consumption reduction apparatus for a resource mining machine,

The present invention relates to a resource extractor for extracting resources such as crude oil and natural gas, and more particularly, by using a counter electromotive force of a resource mining system to regenerate electric power and reduce harmonics to reduce power consumption of a crude oil drill ≪ / RTI >

Natural resources buried underground or seabed are essential for human survival. Therefore, various resource diggers are used. Among them, the Pump Jack system is essential for oil and natural gas exploration. It is used by oil and gas companies in oil and oil fields on land or sea, and the number of pump jacks is increasing rapidly every year. In particular, the number of pump jacks widely distributed in oil producing countries is already over 10 million units.

The pump jack systems developed so far include MEC, SinuMEC, CCW, Turbo Trac System, SMART JACK, Energyldeas, and DIGITEK. MEC is a spreading technology that was developed after the expiration of patents developed by US NASA in the 1970s. It uses a phase control system with secondary resistance control such as single-phase and wound-wire type motors to control the voltage. However, it is not suitable for three-phase induction motor control. SinuMEC shares basic concepts with MEC as Israeli technology. In addition, the CCW in Canada developed a hydraulic system for the reduction gear of the pump jack, but the price is very expensive and the pump jack itself has to be replaced or installed. The Turbo Trac System in the United States uses air to operate the reduction gears of conventional pump jacks using turbine compressors. It is very wear resistant, low noise, very expensive, and the pump jack itself needs to be replaced or installed. The SMART JACK in the USA stops the motor during the downstroke time in which the back electromotive force is generated. Although the power is reduced, the life of the motor and the device is shortened and the power saving rate is less than 10%.

Korean Patent Application No. 20-1995-0028140 discloses a worktable having a frame in which a square upper and lower frame is connected and fixed at a predetermined height and an upper plate attached on an upper frame of the frame, A buoyancy generating means having a plurality of buoyancy members arranged to be spaced apart from each other at a predetermined interval and a wave damping means fixed to four sides of the frame and having a plurality of seawater flow holes on the conical surface, And semi-submersible marine drilling rig which can be moved even at low depth because there is no separate structure at the lower part of the work platform. In the case of using the sea drill ship according to the reference document, by installing a work chamber having a certain depth in the center of a work material, the joining position between the drilling rig body and the drill rod can be raised to an appropriate height.

However, resource mover boasts tremendous revenue and demand in the global marketplace, but its power consumption is very high. In other words, the energy consuming portion of the resource miner is more than the production cost of crude oil mined, so the United States and oil-producing countries or genetically-owned companies are concentrating on reducing power consumption.

Therefore, there is a desperate need for a technique for reducing the power consumption of the resource extractor.

Korean Patent Application No. 20-1995-0028140

It is an object of the present invention to reduce the power consumption of a resource extractor.

In order to accomplish the above objects, the present invention relates to a power saving device for a resource extractor. The apparatus for reducing power consumption according to the present invention includes a harmonic eliminator for generating a driving power applied to an electric motor for operating a resource extractor by reducing a harmonic component of an input power source, A counter electromotive force absorber for absorbing a part of the input power to add to the driving power source, and a torque controller for controlling the torque of the motor by performing proportional calculus control on an error between a control result and a set value of the torque of the electric motor. In particular, the counter electromotive force absorbing unit may include an inverter unit connected to the motor to apply power supplied through a power cable to the motor, a regenerative power generator that receives regenerative power generated by the motor, A main contactor operable to shut off power supplied from the work site power system to the inverter unit, and a controller connected to the line monitoring unit, And a contactor control unit for controlling an operation state of the main contactor. Further, the torque control section may further comprise: a high-pass filter for removing low-frequency components from the control result; an effective-value calculating section for calculating an effective value (RMS) from the output of the high-pass filter; a proportional gain Kp, a differential gain calculating unit for outputting a differential gain Kd according to the proportional gain Kp, and a proportional gain control unit for performing proportional-integral control while changing the control bandwidth based on the proportional gain Kd and the differential gain Kd And a PID control unit.

According to the present invention, since the harmonics of the driving power supplied to the motor driving the resource extractor are reduced, the consumed power of the resource extractor is reduced.

Further, according to the present invention, a part of the negative power generated at the time of down-stroke of the resource extractor is absorbed and included in the power supply of the electric motor, so that the power consumption of the resource extractor is reduced.

Further, according to the present invention, the up-stroke speed of the resource extractor is increased and the down-stroke speed is decreased, so that the unit process cycle is kept constant, thereby reducing the power consumption of the resource extractor.

1 is a view conceptually showing an embodiment of an apparatus 100 for reducing power consumption of a resource extractor according to the present invention.
FIG. 2 is a view showing an embodiment of a pump jack to which the power saving device according to FIG. 1 can be applied.
3 is a block diagram conceptually illustrating the operation of the counter electromotive force absorber 300 included in FIG.
4 is a block diagram conceptually illustrating the operation of the torque control unit 400 included in FIG.
5 is a graph showing an operation cycle before and after the present invention is applied.

In order to fully understand the present invention, operational advantages of the present invention, and objects achieved by the practice of the present invention, reference should be made to the accompanying drawings and the accompanying drawings which illustrate preferred embodiments of the present invention.

Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings. However, the present invention can be implemented in various different forms, and is not limited to the embodiments described. In order to clearly describe the present invention, parts that are not related to the description are omitted, and the same reference numerals in the drawings denote the same members.

1 is a view conceptually showing an embodiment of an apparatus 100 for reducing power consumption of a resource extractor according to the present invention.

1 includes a harmonic eliminator 110, a torque controller 130, a counter electromotive force absorber 150, and an inverter 170. The harmonic eliminator 110, the torque controller 130, the counter electromotive force absorber 150,

The inverter 170 supplies the input power to the motor 190.

The harmonic eliminator 110 reduces the harmonic components of the input power source to generate driving power to be applied to the motor for operating the resource extractor. The harmonic component is caused by the increase of the voltage across C at I = C * dv / dt. In particular, the harmonic eliminator 110 is configured to suppress harmonics that occur when a back electromotive force in a downstroke state occurs in particular. Various devices can be used to suppress harmonics. For example, an L-C filter for fixed harmonic control can be used to suppress the generation of harmonics which are rapidly changed in an up-stroke <-> down-stroke system. However, in order to further improve the suppression performance, it is preferable to use an active filter. Alternatively, a dv / dt filter may be employed.

It is preferable that the harmonic eliminator 110 operates so as to generate a harmonic of 20% at the time of maximum load but reduce it to less than 10%. If the load is 70%, 30% of harmonics are generated at present, but it is desirable that the harmonics are suppressed to less than 20%. If no load is present, the harmonics are preferably less than 50%. In particular, the harmonic eliminator 110 suppresses harmonics generated at the time of downstroke (falling), thereby preventing erroneous operations occasionally occurring.

In the present specification, up-stroke refers to the time when the drilling rig ascends, and down stroke refers to when the drilling rig descends.

The torque control unit 130 controls the torque of the electric motor 190 by performing proportional-integral calculus on the error between the control result of the torque of the electric motor 190 and the set value. That is, the current pump jack operates at a fixed RPM, and since the quantity and cycle of producing crude oil are important, the torque control unit 130 operates so as to speed up the up-stroke and slow down the down-stroke. As a result, the unit process cycles remain the same. As the torque controller 130, a sensorless auto PID system may be used. If the pump jack is equipped with a reduction gear, it is preferable to automatically track down-stroke the down-stroke time because there is no variation in the production cycle. Or a gear moment free system may be implemented so as not to be affected by the force applied to the gear. Preferably, the torque control section 130 tracks and precisely monitors the up-stroke (up-time) and down-stroke (down) torques.

The torque control unit 130 will be described later in detail with reference to FIG. Therefore, repetitive descriptions are omitted for the sake of simplification of the specification.

The counter electromotive force absorbing unit 150 absorbs at least a part of the counter electromotive force generated when the resource extractor enters the underground, and adds it to the driving power source. That is, the counter electromotive force absorbing unit 150 absorbs the negative power generated at the time of the downstroke and feeds back to the input power source AC. At this time, the power consumption is reduced as the stable AC waveform is implemented. The counter electromotive force absorbing unit 150 can maximize the power saving effect by charging the counter electromotive force again at the DC terminal of the inverter 170 and reducing the AC back to the AC power and then regenerating the power to the power source. In this case, the counter electromotive force absorber 150 is added to the DC reactor inside the inverter rather than being manufactured independently, and then it is necessary to share the alternating current reactor (DC) in the inverter for the down- It is economical.

Preferably, the counter electromotive force regenerated in the counter electromotive force absorber 150 reaches approximately 10 to 15% of the electric power.

The counter electromotive force absorbing unit 150 will be described later in detail with reference to FIG. Therefore, repetitive descriptions are omitted for the sake of simplification of the specification.

2 is a view showing an embodiment of a pump jack to which the power saving device according to FIG. 1 can be applied.

The pump jack 200 of Figure 2 includes a walking beam 210, a horse head 220, a drill rod 230, a samson post 240, a gear reducer 250, a V- A belt 260, and a counterweight 270.

The power source of the pump jack 200 is transmitted to the gear reducer 250 through the V-belt. The electric motor drives the working beam 210 so that the hose head 220 can vertically move up and down. The recoil weight 270 balances the hose head 220 with the hose head 220 so that the hose head 220 repeats a certain operation.

There is a hole pump below the drilling rod 230.

In the case of an up stroke, the travel valve is closed and the standing valve is opened. Therefore, the pump barrel is filled with resources, the travel valve is opened and the standing valve is closed. The piston reaches the end of the stroke and repeats the process again.

3 is a block diagram conceptually illustrating the operation of the counter electromotive force absorber 300 included in FIG.

The three-phase alternating-current power is supplied from the power system to the inverter 370 through a power cable. The three-phase alternating-current power is supplied to the electric motor 390 through a power cable. And is supplied to the electric motor 390 through the electric motor 390. In the construction work lift constructed as described above, when the resource extractor moves down, regenerative power is generated. The counter electromotive force absorbing unit 300 includes an electric motor 390, an inverter 370, a regenerative power converting unit 350, a line monitoring unit 340, a contactor 310 and a contactor control unit 320.

The electric motor 390 is configured to move the resource extractor vertically, and is mounted on the top of the resource extractor and is mounted to move with the resource extractor. The three-phase alternating current power is supplied to the electric motor 390 through the inverter 370. The three-phase alternating current power is supplied to the electric motor 390 through the power cable.

The inverter 370 is connected to the motor 390 so as to control the operation state of the motor 390 by applying the supplied three-phase AC power to the motor 390. The inverter 370 is mounted on the top of the resource extractor, And can be mounted to move with the resource extractor.

The regenerative power conversion unit 350 is configured to receive the regenerative power generated by the motor 390 from the inverter 370, convert the regenerative power into commercial power, and output the regenerative power. That is, when the electric motor 390 is operated so that the resource extractor moves down, regenerative electric power is generated in the electric motor 390 by the self weight of the resource extractor, and is applied to the inverter 370. The regenerative electric power conversion unit 350 The regenerative power is received from the inverter 370 and converted into commercial power and output. The commercial power converted and outputted through the counter electromotive force absorbing unit 150 may be supplied to the power system or another general consumer power system through the power cable and used as an additional energy source.

The line monitoring unit 340 is configured to monitor an abnormal state such as disconnection of the power cable. For example, it continually monitors whether an overcurrent, short-circuit current, or current imbalance occurs due to a phenomenon such as disconnection, short-circuit, or ground fault in a power cable.

The contactor 310 is configured to shut off the power supplied from the power system to the inverter 370. The contactor controller 320 receives the monitoring signal of the line monitor 340 to operate the contactor 310 State. That is, the contactor 310 is a contactor mounted on the power cable, and is configured to cut off or connect the power supplied to the inverter 370. This contactor 310 is connected to the contactor controller 320, respectively. At this time, the contactor control unit 320 controls the contactor 310 to turn off the power supply only when the abnormal state of the power cable is continuously monitored by the line monitor unit 340 for a predetermined duration.

Accordingly, when an instantaneous short circuit phenomenon or the like that may be negligible in the power cable occurs, the regenerative power regeneration system according to the embodiment of the present invention maintains the power supply to the inverter 370 to perform normal operation for the motor 390 And at the same time regenerative power can be continuously regenerated.

Meanwhile, the inverter control unit 380 receives the signal from the line monitoring unit 340 and controls the operation state of the inverter 370. The regenerative power conversion unit 350 outputs the normal voltage current until the internal DC voltage of the inverter 370 rises to the inverter limit voltage so that the inverter 370 outputs the converted output voltage from the regenerative power conversion unit 350 And is operatively controlled by the inverter control unit 380 so as to gradually stop the electric motor 390 by receiving commercial power.

According to the counter electromotive force absorbing part 300 as shown in FIG. 3, the electric power at the time of the down stroke is used to drive the electric motor 390 again, so that the power efficiency is improved.

4 is a block diagram conceptually illustrating the operation of the torque control unit 400 included in FIG.

The torque control unit 400 shown in FIG. 4 can be used to control various actuators, but can provide the optimum effect in motor control for motion control such as position, torque, and speed control of a moving part. The torque control unit 400 may be connected to a driver (not shown) for driving an electric motor (not shown). The torque control unit 400 provides a predetermined control value to a driver (not shown) so that a driver (not shown) may control the motor in accordance with the control value and may be installed in a device The error is detected based on the control result fed back from the sensor, and the PID (Proportional Integral Derivative) control is performed. On the other hand, the control of the torque control unit 400 can be divided into a tracking mode and a regulation mode. The tracking mode corresponds to a control for reaching a position, torque or speed of a predetermined target value for an actuator or an apparatus connected to an actuator. The regulation mode corresponds to a control for controlling a hunting phenomenon occurring after reaching a target value by the tracking mode .

4, the torque controller 400 includes an attenuator 420, a PID controller 430, an electric motor 450 to be controlled, and a gain controller 410. The torque controller 400 has a fast tracking performance, Minimize the hunting of the actuator. The attenuator 420 obtains an error, which is a difference between the set value Xs and the control result Xm fed back from the motor 450, and provides it to the PID controller 430. The PID controller 430 may use a known proportional calculator and receives an error from the attenuator 420 and receives a scheduled proportional gain Kp and a derivative gain from the gain controller 410. [ ) Kd ', and provides a proportional-derivative control output to the motor 450. [

In this case, the PID controller 430 performs proportional calculus control while changing its control bandwidth according to the scheduled proportional gain Kp and the differential gain Kd provided by the gain controller 410. Accordingly, the PID controller 430 minimizes hunting of the actuator in the regulation mode while allowing the control result Xm to quickly track the set value Xs.

The gain control unit 410 provides the PID controller 430 with the proportional gain Kp and the differential gain Kd that are previously scheduled according to the RMS based gain scheduling algorithm (RGS) proposed by the present invention, So that the control bandwidth of the control channel is changed according to the control result.

Since the proportional gain Kp and the differential gain Kd are decisive factors for controlling the control bandwidth of the PID controller 430, the 'effective value based gain scheduling algorithm' can change the control bandwidth of the PID controller 430 according to the situation, It is possible to minimize the hunting in the mode.

The gain adjusting unit 410 includes a high pass filter, an effective value calculating unit, a proportional gain calculating unit, and a differential gain calculating unit. The high pass filter removes the low frequency component (or the direct current component) from the feedback control result Xm. The output of the high-pass filter corresponds to an error in the regulation mode and serves as a reference for gain scheduling. The cutoff frequency of the high-pass filter is preferably set to 10 Hz in consideration of the fact that the natural frequency of the building or the like has a natural frequency ranging from 1 Hz to 5 Hz.

The effective-value calculating unit calculates the effective value from the output value of the high-pass filter. The effective value calculating unit may be implemented in software through a DSP (Digital Signal Processing) chip, but it is preferable to use a dedicated converter chip to reduce the phase shift of the effective value and obtain a quick response. The proportional gain calculating unit detects the scheduled proportional gain Kp for the PID controller 430 using the effective value provided by the effective value calculating unit and provides the PID controller 430 and the differential gain calculating unit.

The differential gain calculator calculates the differential gain Kd based on the scheduled proportional gain Kp provided from the proportional gain calculator and provides the differential gain Kd to the PID controller 430. [

As described above, the torque control unit 400 according to the present invention improves the tracking performance by varying the control bandwidth of the PID control by changing the proportional gain and differential gain used for the PID control according to the control result.

In particular, the torque controller 400 senses the voltage and current required for estimating the shaft power, determines the load torque by calculating the power factor, and then determines the rotation speed N required for the load as shown in the following equation (1).

That is, the motor shaft power (power holding torque) P is expressed by the following equation (2).

In the equation (2), Q represents the flow rate (m ³ / min), H represents the pressure or the positive, p represents the pump efficiency, and m represents the motor efficiency.

5 is a graph showing an operation cycle before and after the present invention is applied. 5 (a) is a graph prior to the application of the power saving device according to the present invention. A square wave indicates the direction of the pump, A indicates the motor current, and B indicates the motor torque. On the other hand, in FIG. 5 (b), the square wave represents the direction of the pump and the curve represents the torque of the crank.

As can be seen from FIG. 5, it can be seen that the amount of change in the crank torque according to the direction of the pump is significantly reduced.

Currently, there are about 10 million pump jacks installed in the world and average power consumption is about 45 Kwh. Therefore, even if only 20% of the power consumption is reduced, the global low carbon green energy can be achieved by reducing enormous power saving and carbon dioxide emission.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. For example, the power saving device according to the present invention does not necessarily have to be applied to a resource extracting machine. Rather, it can be installed and applied to industrial equipment such as an injection machine, a press, a compressor and a pump, a blower, a fan, a compressor and the like, and can reduce electric power use in the electric motor sector.

In addition, the method according to the present invention can be embodied as computer-readable code on a computer-readable recording medium. A computer-readable recording medium may include any type of recording device that stores data that can be read by a computer system. Examples of the computer-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and may be implemented in the form of a carrier wave (for example, transmission via the Internet) . The computer readable recording medium may also store computer readable code that may be executed in a distributed manner by a distributed computer system connected to the network.

As used herein, the singular " include " should be understood to include a plurality of representations unless the context clearly dictates otherwise, and the terms "comprises & , Parts or combinations thereof, and does not preclude the presence or addition of one or more other features, integers, steps, components, components, or combinations thereof. The terms "part", "unit", "module", "block", and the like described in the specification mean units for processing at least one function or operation, And a combination of software.

Therefore, it should be understood that the present invention and the drawings attached hereto are only a part of the technical idea included in the present invention, and that those skilled in the art will readily understand the technical ideas included in the specification and drawings of the present invention It is obvious that all the variations and concrete examples that can be deduced are included in the scope of the present invention.

The present invention can be applied to a resource extractor.

110: Harmonic elimination
130:
150: counter electromotive force absorbing part
170, 370: Inverter
190, 390: Electric motor
310: Contactor
320: Contactor control
340: line monitoring unit
350: regenerative power conversion unit
380: inverter control section
410:
430: PID controller
450: electric motor

Claims (3)

As a power saving device for a resource extractor,
A harmonic eliminator for generating a driving power to be applied to an electric motor for operating a resource extractor by reducing a harmonic component of an input power source;
A counter electromotive force absorber absorbing at least a part of a counter electromotive force generated when the resource extractor enters the basement and adding the absorbed power to the driving power; And
And a torque control unit for controlling a torque of the motor by performing proportional calculus control on an error between a control result of the torque of the electric motor and the set value. The apparatus according to claim 1, wherein the counter-
An inverter unit connected to the electric motor so as to apply power supplied through a power cable to the electric motor;
A regenerative power converting unit that receives regenerative power generated by the motor from the inverter unit and converts the regenerative power into commercial power;
A line monitoring unit monitoring an abnormal state of the power cable;
A main contactor operable to shut off power supplied from the work site power system to the inverter unit; And
And a contactor control unit receiving a signal of the line monitoring unit and controlling an operation state of the main contactor. The torque converter according to claim 2,
A high pass filter for removing low frequency components from the control result;
An effective value calculating unit for calculating an effective value (RMS) from the output of the high pass filter;
A proportional gain calculating unit for outputting proportional gain Kp according to the effective value calculated by the effective value calculating unit;
A differential gain calculator for outputting a differential gain Kd according to the proportional gain Kp; And
And a PID controller for performing a proportional and integral calculus control while changing a control bandwidth based on the proportional gain Kd and the differential gain Kd.

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