Disclosure of Invention
The invention provides a method and a system for controlling intermittent pumping of a pumping unit, which are used for reducing the control cost of an intermittent pumping operation system of the pumping unit.
An embodiment of the present application provides a method for controlling intermittent pumping of a pumping unit, including:
the controller receives the value of the instantaneous power of the motor sent by the frequency converter;
the controller calculates the stroke frequency power of the pumping unit according to the instantaneous power of the motor, wherein the stroke frequency power refers to the output work of the pumping unit in one stroke cycle;
the controller obtains average power of a plurality of time periods according to the stroke frequency power, wherein one time period at least comprises one stroke period;
the controller inputs the average power of a plurality of time periods into the intermittent pumping work system identification model to obtain pumping time in one working period;
The controller determines a dwell time in a duty cycle based on the pumping time in the duty cycle.
According to a first implementation manner of the first aspect of the embodiment of the present application, the plurality of time periods are continuous time periods, and the plurality of time periods are equal-length time periods.
According to the first aspect of the embodiment of the present application or the first implementation manner of the first aspect, in a second implementation manner of the first aspect of the embodiment of the present application, the plurality of time periods are specifically three time periods, and average powers of the plurality of time periods include a first average power P1, a second average power P2 and a third average power P3;
The intermittent operation system identification model is TR=a (yP 2-xP1-zP 3)/(uP 1-vP2+wP3), wherein y=x+z, v=u+w, and TR is pumping time in one working cycle.
In a third implementation manner of the first aspect of the embodiment of the present application, based on the first aspect of the embodiment, the first implementation manner and the second implementation manner of the first aspect of the embodiment of the present application, the thinning operation system identification model is tr=12 (7p2-4.5P1-2.5P3)/(p1-2p2+p3), where TR is greater than or equal to 30min and less than or equal to 60min.
According to the first aspect of the embodiment of the present application, any one of the first implementation manner to the third implementation manner of the first aspect, and in a fourth implementation manner of the first aspect of the embodiment of the present application, the controller determines a pumping stop time in a working period according to a pumping time in the working period, and specifically includes:
The pumping time is greater than or equal to a first preset value, and the pumping stopping time is reduced;
The pumping time is less than or equal to a second preset value, and the pumping stopping time is increased;
the pumping time is larger than the second preset value and smaller than the first preset value, and the pumping stopping time is unchanged.
According to the first aspect of the embodiment of the present application, any one of the first implementation manner to the fourth implementation manner of the first aspect of the embodiment of the present application, in a fifth implementation manner of the first aspect of the embodiment of the present application, a minimum value of a pumping stop time TS in one working period is 30min, and a maximum value of the TS is 90min;
when TR is more than or equal to 50min and TS is more than 30min, TS is reduced by 10min;
TR is less than or equal to 40min, and when TS is less than 90min, TS is increased for 10min;
When 50min > TR >40min, TS is unchanged.
According to the first aspect of the embodiment of the present application, any one of the first implementation manner to the fifth implementation manner of the first aspect of the embodiment of the present application, in a sixth implementation manner of the first aspect of the embodiment of the present application, an initial value of the pumping stop time TS in one working period is 60min.
According to the first aspect of the embodiment of the present application, any one of the first implementation manner to the sixth implementation manner of the first aspect, in a seventh implementation manner of the first aspect of the embodiment of the present application, the method further includes:
The detection loop of the frequency converter detects the instantaneous voltage and the instantaneous current of the motor;
The frequency converter calculates the instantaneous power of the motor according to the instantaneous voltage and the instantaneous current of the motor;
the frequency converter sends the value of the instantaneous power of the motor to the controller.
According to the first aspect of the embodiment of the present application, any one of the first implementation manner to the seventh implementation manner of the first aspect of the embodiment of the present application, in an eighth implementation manner of the first aspect of the embodiment of the present application, the controller receives a value of instantaneous power of the motor sent by the frequency converter, and specifically includes:
the controller receives the value of the instantaneous power of the motor sent by the frequency converter through 485 communication.
The second aspect of the embodiment of the application provides a pumping unit intermittent pumping control system, which comprises a frequency converter and a controller, wherein the frequency converter is used for executing the pumping unit intermittent pumping control method of the first aspect;
The power end of the frequency converter is connected with the contactor of the main loop, the load end of the frequency converter is connected with the motor, the controller is connected with the frequency converter in a communication way, and the motor is arranged in the main loop.
From the above technical solutions, the embodiment of the present application has the following advantages:
In the embodiment of the application, the stroke frequency power of the pumping unit is calculated by using the instantaneous power of the motor, so that the output power of the pumping unit in one stroke cycle can be accurately measured. Under the condition that the stroke and the frequency of the stroke of the pumping unit are unchanged, the output work of the pumping unit in one stroke period is positively correlated with the liquid yield of the pumping unit, namely the larger the output work is, the larger the liquid yield is, and the smaller the output work is, the smaller the liquid yield is. The reason for the reduced liquid production is insufficient liquid supply capacity at the bottom of the well. The underground working condition is detected by measuring the output work, and an expensive sensor is not needed to be used underground, so that the cost is saved. In the process of determining the intermittent operation system, firstly, selecting a plurality of time periods, multiplying the impulse power of each time period by the impulse in the time period, and dividing the impulse power by the time period of the time period to obtain the average power. After the controller obtains the average power of each of the plurality of time periods, the average power is input into the intermittent operation system identification model. The intermittent pumping working system identification model is a mathematical model, the input quantity is the average power of a plurality of time periods, and the output quantity is the pumping time in one working period. One duty cycle includes pumping time and stopping pumping time. The controller uses the intermittent pumping operation system identification model to determine pumping time in one period, and further determines pumping stop time in one working period, namely, the operation system of the pumping unit is determined. The controller controls the pumping unit to work according to the working system of the pumping unit, and is simple and feasible and low in cost.
Detailed Description
The invention provides a method and a system for controlling intermittent pumping of a pumping unit, which are used for reducing the control cost of an intermittent pumping operation system of the pumping unit.
The embodiment of the application provides a method for controlling intermittent pumping of a pumping unit, which can be applied to a petroleum sucker rod pumping unit and is realized by a control system consisting of a special frequency converter and a controller of the pumping unit. The controller is internally provided with an intelligent control algorithm which comprises a thinning working system identification model.
A detection loop of a frequency converter in the control system detects the instantaneous voltage and the instantaneous current of the motor, and calculates the instantaneous power (including negative power) of the motor. The controller reads the instantaneous power through 485 communication. The controller processes the instantaneous power to obtain the stroke frequency power, and then detects the power of the pumping unit in a plurality of stroke cycles. And calculating the optimal pumping time and the optimal pumping stopping time through the intermittent pumping work system identification model, and making an intermittent pumping work system to complete self-learning of the working condition of the oil well. The intermittent operation system identification model is a mathematical model for identifying the optimal intermittent operation system so as to maximize the liquid yield. The pumping time and the pumping stop time may also be referred to as pumping duration and pumping stop duration.
The controller controls the frequency converter to work according to the intermittent operation system. In the oil pumping process, the control system detects the change of the stroke frequency power in real time, and performs closed-loop control on the oil pumping unit, so that the balance of oil supply and production and the stable production and efficiency improvement are realized.
According to the embodiment of the application, the stroke frequency power of the oil pumping unit and the average power of a plurality of time periods are calculated by detecting the instantaneous power of the motor, and the intermittent working system based on the mathematical model of the intermittent working system identification model is adopted, so that the maximum liquid yield is obtained. The intelligent oil pumping control of the oil pumping unit is realized by combining a digital filtering technology, a mathematical modeling technology and a variable frequency control technology, so that the purposes of increasing yield, improving efficiency, saving energy and reducing consumption are achieved.
As shown in fig. 1, an embodiment of the present application provides a method for controlling intermittent pumping of a pumping unit, including:
101. the controller receives the value of the instantaneous power of the motor sent by the frequency converter;
102. the controller calculates the stroke frequency power of the pumping unit according to the instantaneous power of the motor, wherein the stroke frequency power refers to the output work of the pumping unit in one stroke cycle;
103. the controller obtains average power of a plurality of time periods according to the stroke frequency power, wherein one time period at least comprises one stroke period;
104. The controller inputs the average power of a plurality of time periods into the intermittent pumping work system identification model to obtain pumping time in one working period;
105. the controller determines a dwell time in a duty cycle based on the pumping time in the duty cycle.
The intelligent control of the oil pumping unit is to obtain the electric parameters of the motor through the frequency converter, indirectly judge the underground working condition through the controller, determine the optimal intermittent pumping working system, track the change of the underground working condition and automatically adjust, so that the oil well always works under the optimal intermittent pumping working system, and the purposes of balanced supply and drainage and maximized liquid production are achieved.
As shown in fig. 2, an embodiment of the present application provides a method for controlling intermittent pumping of a pumping unit, including:
201. the detection loop of the frequency converter detects the instantaneous voltage and the instantaneous current of the motor;
The instantaneous voltage and the instantaneous current of the motor are detected through a special frequency converter, and the instantaneous voltage and the instantaneous current are multiplied to obtain the instantaneous power of the motor.
202. The frequency converter calculates the instantaneous power of the motor according to the instantaneous voltage and the instantaneous current of the motor;
the controller directly reads the instantaneous power of the frequency converter, and the stroke frequency power is obtained by integrating the instantaneous power in one stroke period.
203. The frequency converter sends the value of the instantaneous power of the motor to the controller.
In one implementation, the frequency converter and the controller are connected by 485 communication. The frequency converter sends the value of the instantaneous power of the motor to the controller through 485 communication.
204. The controller receives the value of the instantaneous power of the motor sent by the frequency converter;
in one implementation, the controller receives the value of the instantaneous power of the motor sent by the inverter via 485 communication.
205. The controller calculates the stroke frequency power of the pumping unit according to the instantaneous power of the motor, wherein the stroke frequency power refers to the output work of the pumping unit in one stroke cycle;
the unit of the power of the stroke frequency is kilowatt (kW). One stroke cycle refers to one round of the pumping unit reciprocating.
206. The controller obtains average power of a plurality of time periods according to the stroke frequency power, wherein one time period at least comprises one stroke period;
the average power for a period is the power of the number of times of the time period divided by the time period of the time period.
207. The controller inputs the average power of a plurality of time periods into the intermittent pumping work system identification model to obtain pumping time in one working period;
the controller controls the special frequency converter of the pumping unit to operate under fixed stroke frequency.
In one implementation, the controller measures the average power of three consecutive equal time intervals T, a first average power P1, a second average power P2, and a third average power P3, and the pumping time is obtained from the intermittent operation system identification model.
The intermittent operation system identification model is TR=a (yP 2-xP1-zP 3)/(uP 1-vP2+wP3), wherein y=x+z, v=u+w, and TR is pumping time in one working cycle.
In one implementation, the intermittent operation system identification model is:
tr=12 (7P 2-4.5P1-2.5P3)/(p1-2p2+p3), lower limit of TR value 30min, upper limit of TR value 60min.
208. The controller determines a dwell time in a duty cycle based on the pumping time in the duty cycle.
In one implementation, the pumping time is greater than or equal to a first preset value, and the pumping stopping time is reduced;
The pumping time is less than or equal to a second preset value, and the pumping stopping time is increased;
the pumping time is larger than the second preset value and smaller than the first preset value, and the pumping stopping time is unchanged.
In one implementation, the shutdown time TS is 60min at an initial value, 30min at a minimum value, and 90min at a maximum value, and is adjusted according to the following rule:
When TR is more than or equal to 50min and TS is more than 30min, the TS is TS-10 of the last time, namely TS is reduced by 10min;
TR is less than or equal to 40min, and when TS is less than 90min, the TS is TS+10 of the last time, namely TS is increased for 10min;
And when the time of 40min < TR <50min, TS is not changed, and the last pumping stop time is maintained.
The initial execution of steps 204 through 208 may be referred to as a self-learning phase, and the subsequent looping execution of steps 204 through 208 may be referred to as a closed-loop control phase.
In the self-learning stage, the controller measures the time-varying data of the stroke frequency power of the pumping unit through the frequency converter and draws a mathematical model of the time-varying stroke frequency power. Determining an optimal intermittent working system corresponding to the maximum liquid yield according to a mathematical model of the change of the impulse power along with time and an intermittent working system identification model;
and in the closed-loop control stage, taking the calculated pumping time and the calculated pumping stopping time in the optimal intermittent pumping working system as given values of the reference working system. And the closed loop control of the system is performed by combining the change of the underground liquid supply capacity, so that stable yield and yield increase are realized.
As shown in fig. 3 to 4, the embodiment of the application provides a pumping unit intermittent pumping control system, which comprises a frequency converter and a controller, wherein the frequency converter and the controller are used for executing a pumping unit intermittent pumping control method, a power end of the frequency converter is connected with a contactor of a main loop, a load end of the frequency converter is connected with a motor, the controller is in communication connection with the frequency converter, and the motor is arranged in the main loop.
The control system takes a special frequency converter and an intelligent controller of the pumping unit as cores and is used for identifying the optimal intermittent pumping operation system of the pumping unit. The power end of the special frequency converter of the pumping unit of the control system is connected with the contactor of the main loop, and the load end is connected with the motor. The control system also comprises a controller with an intelligent control algorithm, and the controller is a special controller for the pumping unit and exchanges data with the frequency converter through communication.
As shown in fig. 3, the input end of the frequency converter acquires the dc bus voltage and the set frequency. The DC bus voltage is input into a DC voltage regulator to obtain additional output frequency, and the set frequency is input into an acceleration and deceleration ramp integrator to obtain basic output frequency. The basic output frequency and the additional output frequency are intersected, and positive feedback gain is carried out to obtain the output frequency. The output frequency is input into the SPWM control unit, and is also input with a V/F curve and a closed-loop control operation signal sent by the controller. The output end of the SPWM control unit is the output end of the frequency converter, and the output end of the frequency converter is connected with the motor. The frequency converter collects the voltage and the current of the output end and calculates the instantaneous power of the motor. The obtained motor instantaneous power is input into the controller.
And the impulse power consumption calculation unit of the controller receives the motor instantaneous power sent by the frequency converter and inputs the motor instantaneous power into the controller, and the impulse power consumption calculation unit outputs impulse power consumption to the self-learning model and the well condition dynamic tracking model. And obtaining pumping time according to the power consumption of the flushing times by the self-learning model, further obtaining pumping stopping time, and determining a intermittent pumping working system. And inputting the intermittent working system into a well condition dynamic tracking model. The well condition dynamic tracking model outputs a closed-loop control operation signal to the SPWM control unit of the frequency converter.
As shown in FIG. 4, the U port, the V port, the W port and the PE port of the frequency converter are respectively connected with the U1 port, the V1 port, the W1 port and the grounding port of the motor, the R port, the S port and the T port are respectively connected with the output port of the contactor to supply power to the frequency converter, the K1 port, the K2 port and the COM port are respectively connected with normally open contacts of KA1 and KA2 of the relay to respectively control the operation and the stop of the frequency converter, the 1 port and the 2 port are respectively connected with the DC reactor, and the A+ port and the B-port are connected with a 485 bus to communicate with the controller.
It should be understood that, although the steps in the flowcharts related to the above embodiments are sequentially shown as indicated by arrows, these steps are not necessarily sequentially performed in the order indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least some of the steps in the flowcharts described in the above embodiments may include a plurality of steps or a plurality of stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of the steps or stages is not necessarily performed sequentially, but may be performed alternately or alternately with at least some of the other steps or stages.
It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, which are not repeated herein.
The terms first, second, third, fourth and the like in the description and in the claims and in the above drawings are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments described herein may be implemented in other sequences than those illustrated or otherwise described herein.
In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of elements is merely a logical functional division, and there may be additional divisions of actual implementation, e.g., multiple elements or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.
The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be embodied in essence or a part contributing to the prior art or all or part of the technical solution in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of the embodiments of the present application. The storage medium includes a usb disk, a removable hard disk, a read-only memory (ROM), a random access memory (RAM, random access memory), a magnetic disk, an optical disk, or other various media capable of storing program codes.