Anti-interference electricity controller of oil pumping unit

Abstract

The invention discloses an anti-interference electricity controller of a pumping unit, and relates to the technical field of electrical control, and the anti-interference electricity controller comprises a data acquisition module which is used for acquiring the motor type, the load, the interference electricity duration and the interference electricity frequency; the dynamic delay calculation module is used for calculating recovery delay through a dynamic self-adaptive algorithm according to the collected information; and a hierarchical recovery control module. Through the control logic of low-frequency starting and stepped frequency rising, the motor can be gradually transited to the rated rotating speed from the lower rotating speed, the current impact at the starting moment is effectively reduced, core equipment such as the motor and a frequency converter is protected against damage, the instantaneous load pressure on a power grid is also reduced, and the stability of the voltage of the power grid is favorably maintained. The staged recovery mode is combined with precise delay control provided by a dynamic adaptive algorithm to form a double guarantee mechanism of delay adaptation and stable starting, and the safety and reliability of anti-interference electricity control are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrical control, in particular to an anti-swing power controller for pumping units. BACKGROUND

[0002] In the field of industrial production, the stability of the power system is directly related to the continuity of the production process and the safe operation of the equipment. Among them, as a common power grid abnormal phenomenon, the swing power usually shows the instantaneous drop, short interruption or severe fluctuation of the power grid voltage, which has various causes, which may be caused by external power grid failure, lightning, load mutation or power supply system switching, etc. Although this power disturbance is short in duration, it has a significant impact on industrial equipment driven by motors, especially in continuous production industries such as petroleum, chemical industry, metallurgy, etc. Swing power may cause motor to stop suddenly, production line to be interrupted, and thus cause production to be stalled, raw materials to be wasted, equipment to be damaged, etc.

[0003] The traditional anti-swing power control scheme generally adopts a fixed delay recovery strategy when dealing with such problems, that is, a fixed time interval (from tens of seconds to hundreds of seconds) is preset, and after the swing power ends, the motor restart operation is performed according to the fixed delay. At the same time, its recovery condition is relatively simple, mainly relying on the simple detection of whether the motor is reversed and whether there is personnel intrusion. However, this mode has obvious limitations: on the one hand, different types of motors (such as reciprocating and rotating) have significant differences in structural characteristics, starting requirements and load tolerance, and the fixed delay cannot adapt to the individual needs of various equipment; on the other hand, the duration, frequency and actual load state of the power grid swing power will directly affect the impact risk of the motor restart, and the single recovery logic is difficult to balance the safety of the equipment and the production efficiency, which may cause the restart current impact to be too large to damage the equipment, or the delay to be too long to aggravate the production loss. With the improvement of industrial automation level, the intelligent and fine recovery strategy after swing power is increasingly required, and the traditional scheme has been difficult to meet the needs of modern industrial production.

[0004] At present, there is no effective solution to the problems in the related art. SUMMARY

[0005] In view of the problems in the related art, the anti-swing power controller for pumping units is proposed to overcome the above technical problems existing in the prior art.

[0006] The technical scheme of the present application is as follows:

[0007] The anti-swing power controller for pumping units comprises:

[0008] The data acquisition module is configured to acquire the motor type, the load, the swing power duration and the swing power frequency.

[0009] a dynamic delay calculation module, connected to the data acquisition module, for calculating the recovery delay through a dynamic adaptive algorithm according to the acquired information;

[0010] a hierarchical recovery control module, connected to the dynamic delay calculation module, for starting the motor at a low frequency first and then gradually recovering to the rated speed according to the calculated recovery delay after the power swing, so as to reduce the current impact.

[0011] Further, it further comprises a safety detection module for detecting whether the motor is reversed and whether there is personnel intrusion, wherein the detection allows the motor to start only when there is no reversal and no intrusion through the hierarchical recovery control module.

[0012] Further, the dynamic adaptive algorithm for calculating the recovery delay is represented as:

[0013]

[0014] wherein T0 is the basic delay, K1 is the motor type weight coefficient, K2 is the load coefficient, K3 is the power swing duration coefficient, K4 is the power swing frequency coefficient, [1+α×exp(-β×t)] is the nonlinear correction term, t is the power swing duration, α is the attenuation coefficient, β is the time constant, and γ(L,t) is the cross-influence factor.

[0015] Further, the K1 is the motor type weight coefficient, which is set according to the motor type, wherein it includes the pumping unit, which is represented as K1=1.4+0.1×n, n is the stroke frequency, n≤5, the centrifugal pump, which is represented as K1=0.9-0.05×q, q is the flow coefficient, 0

[0016] Further, the K2 is the load coefficient, which is represented as:

[0017]

[0018] wherein L is the actual load, L E is the rated load, when the load is heavy K2=1.0;

[0019] when the load is light K2=0.6.

[0020] Further, the K3 is the power swing duration coefficient, which is represented as:

[0021] K3=1+0.1×t;

[0022] Wherein, 1 is a reference coefficient, 0.1 is a time influence coefficient, t is the duration of power swing, and K3≤2.0. Further, the K4 is a power swing frequency coefficient, expressed as:

[0023] K4=1+0.15f+0.05f 2 ;

[0024] Wherein, f is the number of power swings within 1 hour, and K4≤1.8; 0.15 is a linear correction coefficient, and 0.05 is a quadratic correction coefficient.

[0025] Further, the cross-influence factor γ(L,t) is a piecewise function for describing the coupling relationship between the load and the duration of power swing, expressed as:

[0026]

[0027] Further, the hierarchical recovery control module comprises a frequency adjustment unit for gradually increasing the motor starting frequency from an initial low frequency to a rated frequency.

[0028] Further, the initial frequency of the low-frequency start is 30%-50% of the rated frequency, the frequency amplitude of each increase is 10%-20% of the rated frequency, and the interval time of each increase is 1-3 seconds.

[0029] The present application has the following beneficial effects:

[0030] The present application breaks through the limitations of the traditional fixed delay recovery mode by introducing a dynamic adaptive algorithm, realizes intelligent adjustment of the motor recovery strategy, accurately calculates the recovery delay through the synergistic effect of multiple coefficients, and makes the recovery process adapt to the characteristic differences of different equipment and complex power grid conditions. For different types of motors, the algorithm can automatically adjust the delay reference according to the starting characteristics and load tolerance; for the dynamic changes of the load, it can balance the starting impact and recovery efficiency through a nonlinear correction mechanism; and for the duration and frequency of power swing, the algorithm reflects the influence of short-term disturbance and cumulative effect through hierarchical coefficients, so as to maximize the recovery time and reduce the production interruption loss under the premise of ensuring the safety of the equipment.

[0031] Meanwhile, the step-by-step recovery mechanism adopted by the application further optimizes the smoothness of the motor restart process. Through the control logic of low-frequency starting and step-by-step frequency increasing, the motor can gradually transition from a lower speed to a rated speed, effectively reducing the current impact at the starting moment, not only protecting the core equipment such as the motor and the frequency converter from damage, but also reducing the instantaneous load pressure on the power grid, which is conducive to maintaining the stability of the power grid voltage. This step-by-step recovery method, combined with the precise delay control provided by the dynamic adaptive algorithm, forms a dual protection mechanism of "delay adaptation and smooth start", which not only improves the safety and reliability of the anti-swing power control, but also meets the requirements of modern industrial production for continuity and efficiency, and has wide application value. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0033] Figure 1 It is a principle block diagram of the pumping unit anti-swing power controller according to the embodiment of the present application. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.

[0035] According to the embodiment of the present application, a pumping unit anti-swing power controller is provided.

[0036] As shown in Figure 1 The pumping unit anti-swing power controller according to the embodiment of the present application comprises:

[0037] The data acquisition module 1 is used to acquire the motor type, load, swing power duration and swing power frequency.

[0038] The dynamic delay calculation module 2 is used to connect the data acquisition module 1, calculate the recovery delay through the dynamic adaptive algorithm according to the acquired information, and is expressed as:

[0039]

[0040] Wherein, T0 is the basic delay, which can be set to 10s, and is the minimum delay benchmark to ensure the safety of the equipment.

[0041] Wherein, K1 is the motor type weight coefficient, which is set according to the motor type:

[0042] The pumping unit is represented as: K1=1.4+0.1×n, n is the stroke frequency / minute, n≤5;

[0043] In the technical solution, 1.4 is the basic weight coefficient of the pumping unit. The pumping unit belongs to reciprocating heavy load equipment, and has large torque fluctuation when starting. After shutdown, the pumping unit is prone to generate reverse force due to the suspension point load. Experimental data show that the basic recovery delay of the pumping unit needs to be 40% higher than that of ordinary motors, so 1.4 is taken as the benchmark. 0.1 is the stroke frequency correction coefficient. The higher the stroke frequency n (times / minute) of the pumping unit, the greater the motion inertia of the pumping unit, and the more obvious the starting impact. Through 10 groups of experiments with different strokes, it is verified that the recovery delay needs to be increased by about 10% for every increase of 1 time / minute of stroke, so 0.1 is taken.

[0044] The centrifugal pump is represented as: K1=0.9-0.05×q, q is the flow coefficient, 0

[0045] In the technical solution, 0.9 is the basic weight coefficient of the centrifugal pump. The centrifugal pump belongs to rotary light load equipment, and has stable starting characteristics. Experimental data show that the basic recovery delay of the centrifugal pump can be 10% lower than that of the pumping unit, so 0.9 is taken. 0.05 is the flow coefficient correction coefficient. The greater the flow coefficient q, the smaller the inertia of the medium in the pump, and the weaker the starting impact. Through simulation verification, the recovery delay can be reduced by about 0.5% for every increase of 0.1 of q, so 0.05 is taken.

[0046] The reciprocating pump is represented as: K1=1.1.

[0047] Specifically, the reciprocating pump (such as a plunger pump and a diaphragm pump) belongs to a positive displacement pump. Its working principle is to transport medium through the reciprocating motion of the piston / plunger. The characteristics of the reciprocating pump are different from those of the pumping unit (heavy load, reciprocating) and the centrifugal pump (light load, rotary): when starting, due to the incompressibility of the medium, the reciprocating pump will generate a medium degree of pressure impact (lower than the mechanical impact of the pumping unit, but higher than the fluid impact of the centrifugal pump); after shutdown, the medium backflow risk in the pump is medium, and it is not necessary to buffer for a long time like the pumping unit, but it also cannot be restarted quickly like the centrifugal pump. Therefore, 1.1 is taken as the weight coefficient, which means that the recovery delay of the reciprocating pump needs to be increased by 10% on the basis of the basic delay T0, so as to balance the starting characteristics of the reciprocating pump, ensure safe buffering, and avoid excessively prolonging the recovery time to affect production efficiency.

[0048] Wherein, K2 is the load coefficient, which is represented as:

[0049]

[0050] Wherein, L is the actual load, L E The rated load is L K2 = 1.0;

[0051] Light load K2 = 0.6.

[0052] The technical solution, 0.6 is the light load base coefficient, when the load is 0, i.e. , the motor starting impact is minimum, experimental data shows that the recovery delay can be reduced to 60% of the base value, so take 0.6. 0.3 is the linear correction coefficient, when the load increases, the starting current increases linearly, through the test of 10 different types of motors, when the load increases by 10% of the rated value, the recovery delay needs to increase by about 3%, so take 0.3. 0.1 is the nonlinear correction coefficient, when the load exceeds 70% of the rated value, the starting current increases in quadratic curve (such as the current impact is 2-3 times of the light load), the quadratic term needs to be introduced to strengthen the correction, and experimental verification shows that taking 0.1 can match the actual characteristics.

[0053] Wherein, K3 is the duration of power swing coefficient, indicating:

[0054] K3 = 1 + 0.1 x t;

[0055] Wherein, 1 is the base coefficient, 0.1 is the time influence coefficient, t is the duration of power swing, and K3≤2.0, the longer the duration of power swing, the greater the coefficient, but the upper limit is set to avoid excessive growth of delay.

[0056] Wherein, K4 is the power swing frequency coefficient, which is expressed as:

[0057] K4 = 1 + 0.15f + 0.05f 2 ;

[0058] Wherein, f is the number of power swings within 1 hour, and K4≤1.8; 0.15 is the linear correction coefficient, and 0.05 is the quadratic correction coefficient, which is used to quantify the influence of the number of power swings f per unit time on the recovery delay, and the value is obtained based on the fluctuation characteristics of the power grid, the cumulative damage law of the equipment and experimental data.

[0059] Wherein, [1 + α x exp (-β x t)] is a nonlinear correction term, α is the decay coefficient, which is 0.3-0.5, indicating the initial correction amplitude; β is the time constant, which is 0.2-0.4, controlling the decay rate;

[0060] Specifically, short power swing, i.e. t<2s, the motor speed drops a little but the inertia impact is large, about 30%-50% delay is increased through the exponential term; long power swing t>5s, the correction term tends to 1, avoiding repeated superposition.

[0061] Wherein, the cross-influence factor γ(L,t) is a piecewise function, which is used to describe the coupling relationship between load and power swing duration, and is expressed as:

[0062]

[0063] Specifically, in the case of light load and short power swing, the motor is prone to generate reverse torque due to inertia, and the delay time needs to be slightly extended; in the case of heavy load and short power swing, the current impact increases with time, and the delay time needs to be significantly extended; after long power swing, the heavy load motor has completely stopped, and the delay time can be shortened to avoid overheating.

[0064] The hierarchical recovery control module 3 is used to connect the dynamic delay calculation module 2, and after power swing, the motor is started at low frequency according to the calculated recovery delay, and then gradually recovers to the rated speed to reduce the current impact.

[0065] Specifically, according to the calculated recovery delay, the motor is started at low frequency, the initial frequency is 30%-50% of the rated frequency, then the frequency is increased by 10%-20% of the rated frequency each time, and the interval time is 1-3 seconds each time, and gradually recovers to the rated speed.

[0066] Further comprising a safety detection module 4 for detecting whether the motor is reversed and whether there is personnel intrusion, and only when there is no reverse and no intrusion, the motor is allowed to start, ensuring the safety of equipment and personnel.

[0067] The technical solution can detect whether the motor is reversed, and the key equipment in oilfield production, such as the pumping unit, relies on the forward rotation of the motor to realize normal operation, and the reverse rotation may cause mechanical structure jamming, transmission component damage, such as gear box reverse impact, and even cause safety accidents such as pumping rod fracture and well leakage. Therefore, the motor must be started and recovered only when it is confirmed that the motor is not reversed, so as to avoid secondary damage. In practical application, a special forward and reverse rotation sensor can be deployed to monitor the rotation direction of the motor in real time, and determine whether it is in a reverse state, i.e. opposite to the rotation direction in normal operation; if the motor is detected to be reversed, the controller will prohibit the motor from starting, even if the recovery condition is met after power swing.

[0068] In addition, for detecting whether there is personnel intrusion, when the motor restarts, the mechanical components may suddenly operate, such as the up and down movement of the pumping unit horse head, and if there is personnel working near the equipment or mistakenly entering at this time, it may cause safety accidents such as collision and extrusion. Therefore, the motor must be started only when it is ensured that there is no personnel in the working area to ensure the safety of personnel. In application, an intrusion sensor can be deployed to detect whether there is personnel entering or moving object intrusion in the working area in real time; if personnel intrusion is detected, the controller will prohibit the motor from starting, even if the recovery condition is met after power swing.

[0069] Specifically, by means of the above technical solution, taking a heavy load pumping unit as an example, the specific implementation is as follows:

[0070] The data acquisition module 1 collects that the motor type is pumping unit, the stroke frequency n = 4 times / min, the actual load L = 0.9L E , the fluctuation duration t = 3s, the fluctuation frequency f = 2 times in 1 hour; the recovery delay T0 = 10s is calculated;

[0071] K1 = 1.4 + 0.1x4 = 1.8;

[0072] K2 = 0.6 + 0.3x0.9 + 0.1x0.81 = 0.951;

[0073] K3 = 1 + 0.1x3 = 1.3,

[0074] K4 = 1 + 0.15x2 + 0.05x4 = 1.5;

[0075] Wherein, the non-linear correction term, that is, α = 0.4, β = 0.3, 1 + 0.4xexp(-0.3x3)x1.15;

[0076] The cross-influence factor, that is, heavy load (L > 0.7L E ) + t = 3s < 5s, γ = 1.5 - 0.02x9 = 1.32;

[0077] Substituting the formula, that is, T D = 10x(1.8x0.951x1.14x1.5)x1.15x1.32 ≈ 10x4.52x1.15x1.32 ≈ 69.8s;

[0078] The safety detection module 4 detects that the motor has no reverse rotation and no personnel intrusion;

[0079] The hierarchical recovery control module 3 starts the motor at 40% of the rated frequency according to the recovery delay of 69.8s, and after 2s, the frequency is raised to 60% of the rated frequency, and after 2s, it is raised to 80% of the rated frequency, and after 2s, it is raised to the rated frequency, and the starting is completed.

[0080] In addition, in the implementation process, taking a light load centrifugal pump as an example, the specific implementation is as follows:

[0081] The data acquisition module 1 collects that the motor type is centrifugal pump, the flow coefficient q = 0.8, the actual load L = 0.2L E , the fluctuation duration t = 2s, the fluctuation frequency f = 1 time in 1 hour;

[0082] The recovery delay T0 = 10s is calculated;

[0083] K1 = 0.9 - 0.05x0.8 = 0.86;

[0084] K2=0.6+0.3x0.2+0.1x0.04=0.664;

[0085] K3=1+0.1x2=1.2,

[0086] K4=1+0.15x1+0.05x1=1.20;

[0087] Nonlinear correction term, namely, alpha=0.3, beta=0.2, 1+0.3xexp(-0.2x2)≈1.21;

[0088] Cross-influence factor, namely, light load (L<0.3L E )+t=2s<4s, gamma=1.2-0.05x2=1.10;

[0089] Substitute the formula, namely:

[0090] T D =10x(0.86x0.664x1.10x1.20)x1.21x1.10≈10x0.75x1.21x1.10≈9.9s;

[0091] The safety detection module 4 detects that the motor is not reversed and no personnel intrusion;

[0092] The hierarchical recovery control module 3 starts the motor at 30% of the rated frequency according to the recovery delay of 9.9s, and after 1s, the frequency is raised to 50% of the rated frequency, and after 1s, it is raised to 70% of the rated frequency, and after 1s, it is raised to the rated frequency, and the starting is completed.

[0093] In summary, by means of the above technical solutions of the application, the following effects can be achieved:

[0094] The application introduces a dynamic adaptive algorithm, breaks through the limitations of the traditional fixed delay recovery mode, realizes intelligent adjustment of the motor recovery strategy, accurately calculates the recovery delay through the synergistic effect of multiple coefficients, and makes the recovery process adapt to the characteristic differences of different equipment and complex power grid conditions. For different types of motors, the algorithm can automatically adjust the delay reference according to the starting characteristics and load tolerance; for the dynamic changes of the load, the nonlinear correction mechanism can balance the starting impact and recovery efficiency; and for the duration and frequency of the power swing, the algorithm reflects the influence of short-term disturbance and cumulative effect through hierarchical coefficients, so as to maximize the recovery time and reduce the production interruption loss under the premise of ensuring the safety of the equipment.

[0095] Meanwhile, the hierarchical recovery mechanism innovatively adopted by the application further optimizes the smoothness of the motor restart process. Through the control logic of low-frequency starting and stepwise frequency increasing, the motor can gradually transition from a lower speed to a rated speed, effectively reducing the current impact at the starting moment, not only protecting the core equipment such as the motor and the frequency converter from damage, but also reducing the instantaneous load pressure on the power grid, which is conducive to maintaining the stability of the power grid voltage. This phased recovery method, combined with the precise delay control provided by the dynamic adaptive algorithm, forms a dual protection mechanism of "delay adaptation and smooth start", which not only improves the safety and reliability of the anti-flicker control, but also meets the requirements of continuous and efficient production in modern industrial production, and has wide application value.

[0096] The above description is merely the preferred embodiment of the present application, and is not intended to limit the present application. Those skilled in the art will easily think of other embodiments of the present disclosure after considering the disclosure in the specification and examples. The present application is intended to cover any variations, uses or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or conventional techniques in the art that are not disclosed by the present disclosure. The specification and examples are only considered as exemplary, and the true scope and spirit of the present disclosure are indicated by the claims.

[0097] It should be understood that the present disclosure is not limited to the precise structures described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. An anti-sloshing controller for an oil pumping unit, characterized in that, include: The data acquisition module (1) is used to acquire motor type, load, duration of voltage fluctuation and frequency of voltage fluctuation; The dynamic delay calculation module (2) is used to connect to the data acquisition module (1) and calculate the recovery delay based on the acquired information using a dynamic adaptive algorithm. The graded recovery control module (3) is used to connect to the dynamic delay calculation module (2). After the power outage, the controller first starts the motor at a low frequency according to the calculated recovery delay, and then gradually restores it to the rated speed to reduce the current surge.

2. The anti-sloshing controller for oil pumping units according to claim 1, characterized in that, Also includes: The safety detection module (4) is used to detect whether the motor is reversing and whether there is intrusion. The motor is only allowed to start through the graded recovery control module (3) when there is no reversal and no intrusion.

3. The anti-sloshing controller for oil pumping units according to claim 1, characterized in that, The dynamic adaptive algorithm calculates the recovery delay, which is expressed as: Where T0 is the base delay, K1 is the motor type weighting coefficient, K2 is the load coefficient, K3 is the power sloshing duration coefficient, K4 is the power sloshing frequency coefficient, [1+α×exp(-β×t)] is the nonlinear correction term, t is the power sloshing duration, α is the attenuation coefficient, β is the time constant, and γ(L,t) is the cross-influence factor.

4. The anti-sloshing controller for oil pumping units according to claim 3, characterized in that, K1 is the weighting coefficient for motor type, which is set according to the motor type. For pumping units, it is expressed as: K1 = 1.4 + 0.1 × n, where n is the number of strokes per minute and n ≤ 5; for centrifugal pumps, it is expressed as: K1 = 0.9 - 0.05 × q, where q is the flow coefficient and 0 < q ≤ 1; or for reciprocating pumps, it is expressed as: K1 = 1.

1.

5. The anti-sloshing controller for oil pumping units according to claim 3, characterized in that, K2 is the load factor, expressed as: Where L is the actual load, L E This is the rated load; under heavy load... K2 = 1.0; Light load K2 = 0.

6.

6. The anti-sloshing controller for oil pumping units according to claim 5, characterized in that, K3 is the duration coefficient of the voltage flicker, which means: K3 = 1 + 0.1 × t; Where 1 is the baseline coefficient, 0.1 is the time influence coefficient, t is the duration of the electric sloshing, and K3≤2.

0.

7. The anti-sloshing controller for oil pumping units according to claim 6, characterized in that, K4 is the frequency coefficient of electric sloshing, expressed as: K4=1+0.15f+0.05f 2 ; Where f is the number of times the power wave occurs within 1 hour, and K4≤1.8; 0.15 is the linear correction coefficient, and 0.05 is the quadratic correction coefficient.

8. The anti-sloshing controller for oil pumping units according to claim 7, characterized in that, The cross-influence factor γ(L,t) is a piecewise function used to describe the coupling relationship between the load and the duration of voltage dips, expressed as:

9. The anti-sloshing controller for oil pumping units according to claim 1, characterized in that, The graded recovery control module (3) includes a frequency adjustment unit, which is used to gradually increase the motor starting frequency from the initial low frequency to the rated frequency.

10. The anti-sloshing controller for an oil pumping unit according to claim 9, characterized in that, The initial frequency of the low-frequency start is 30%-50% of the rated frequency, the frequency increase amplitude of each increase is 10%-20% of the rated frequency, and the interval between each increase is 1-3 seconds.

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