Control method, device and system for regulating power grid voltage during fracturing operation

Abstract

The invention discloses a control method, device and system for power grid voltage regulation during fracturing operation, and belongs to the technical field of fracturing of oil and gas exploitation, and the method comprises the following steps: during fracturing operation of fracturing equipment, executing a first control strategy; the first control strategy is a remote control strategy, under the remote control strategy, power and voltage changes are detected behind the voltage regulator, and the controller makes corresponding responses in time so as to avoid voltage sudden increase and sudden decrease caused by load fluctuation; during the non-fracturing working period of the fracturing equipment, a second control strategy is executed; the second control strategy is a local control strategy, and the local control strategy is used for protecting the service life of the equipment and avoiding the reduction of the service life times of the equipment caused by gear shifting. According to the invention, smooth engineering construction can be ensured, and the maintenance cost of equipment is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of fracturing for oil and gas production, and more specifically, to a control method, device and system for regulating power grid voltage during fracturing operations. Background Art

[0002] In the fracturing process of oil and gas extraction, under the same construction scale, compared with traditional diesel-driven fracturing, the output power of electric-driven fracturing skids is increased by 50%, while the noise generated is reduced by 20%. However, the promotion of electric-driven fracturing faces many difficulties. The quality of power grids in some areas is poor and very unstable. The 10kv dedicated line used in the early drilling process can only meet the needs of drilling, and fracturing equipment cannot use this power grid. If a new 10kv or 35kv dedicated line is added, it will face the problem of long approval cycle and high cost, and it will not meet the use and promotion of electric-driven fracturing.

[0003] By incorporating energy storage devices into the front end of the electric drive device, the problem of the power demand of the electric drive device is solved. However, it is unable to solve the problem of voltage fluctuations in the internal microgrid when the power of the electric drive device fluctuates during operation. Therefore, there is an urgent need in the art for a suitable control strategy to respond to the technical problem of internal voltage fluctuations caused by load fluctuations. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a control method, device and system for regulating the voltage of a power grid during a fracturing operation, which can ensure smooth construction and reduce the maintenance cost of the equipment.

[0005] The object of the present invention is achieved through the following solutions:

[0006] A control method for regulating grid voltage during fracturing operation, in the fracturing process of oil and gas production, comprises the following steps:

[0007] During the fracturing operation of the fracturing equipment, a first control strategy is executed; the first control strategy is a remote control strategy, under which the controller responds accordingly in a timely manner by detecting changes in power and voltage behind the voltage regulator, so as to avoid sudden increases and decreases in voltage caused by load fluctuations;

[0008] During the non-fracture operation of the fracturing equipment, a second control strategy is executed; the second control strategy is a local control strategy, and the local control strategy is used to protect the equipment life and avoid a reduction in the equipment life due to gear adjustment.

[0009] Furthermore, the remote control strategy detects the power and voltage changes behind the voltage regulator, and the controller responds accordingly in time to avoid sudden increase and decrease of voltage caused by load fluctuation, which specifically includes the following sub-steps:

[0010] S1, when the fracturing equipment starts to work, the power supply control system detects the voltage V and apparent power S of the input end of the fracturing equipment in real time through the mutual inductor; when the apparent power S is greater than the first set value, the fracturing operation starts; otherwise, the operation ends;

[0011] S2, detecting the apparent power S and the voltage V at the load end, when the apparent power S is greater than the second set value, issuing a start command to the remote controller, and remotely controlling the SVR system through the remote controller, otherwise returning to step S1;

[0012] S3, when the apparent power S increases to a certain value and the grid voltage at the load end is less than the third set value, the SVR system starts to prepare for automatic upshifting;

[0013] S4, after the gear up is completed, it is determined again whether the current grid voltage at the load end is less than the third set value, if so, the gear up is continued; if so, the gear is maintained if it is greater than the third set value and less than the fourth set value;

[0014] S5, when the voltage is higher than the fourth set value, it will downshift to make the voltage between the third set value and the fourth set value; when the apparent power at the fracturing load end decreases, the voltage at the grid input end will increase, which will cause the voltage at the load end to increase, thereby performing a downshift until the apparent power is less than the first set value, ending the remote control program, ending the operation, and the power supply control system sends and starts the local control program, and the remote controller waits for the next fracturing operation.

[0015] Further, in step S1, the transformer includes a 10kv CT transformer and a 10kv PT transformer.

[0016] Further, in step S1, the first set value is 300 kVA.

[0017] Further, in step S2, the second set value is 500 kva.

[0018] Further, in step S3, the third set value is 10.3 kV.

[0019] Furthermore, in step S3, the time for upshifting is determined according to the voltage drop range at that time.

[0020] Furthermore, the fourth set value is 10.8 kV.

[0021] A control device for regulating power grid voltage during fracturing operations comprises a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is loaded by the processor, the method described in any one of the above items is executed.

[0022] A control system for regulating power grid voltage during fracturing operation comprises the control device for regulating power grid voltage during fracturing operation as described above.

[0023] The beneficial effects of the present invention include:

[0024] The solution of the present invention proposes a new and appropriate control strategy for responding to the problem of internal voltage fluctuations caused by load fluctuations. It can solve the problem of sudden increase or decrease in voltage caused by load fluctuations. At the same time, it can protect the life of the equipment and avoid a reduction in the life of the equipment caused by gear adjustment, thereby ensuring smooth construction while reducing the maintenance cost of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] Figure 1 is a flowchart of the steps of the method according to the embodiment of the present invention;

[0027] Figure 2 1 is a structural block diagram of a system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] All features disclosed in all embodiments in this specification, or steps in all methods or processes implicitly disclosed, except for mutually exclusive features and / or steps, can be combined and / or expanded or replaced in any manner.

[0029] For existing energy storage technology, grid-connected following is performed. When the load of the fracturing equipment fluctuates, the power changes in real time. The load power fluctuation leads to voltage fluctuation, and the voltage at the grid input end is unstable. Both fluctuations will cause the instability of the back-end grid of the voltage regulator. The following solution is proposed:

[0030] In a preferred embodiment, two sets of control strategies are executed during the fracturing operation and non-operating period. Among them, during the fracturing operation, the remote control strategy is executed, and the changes in power and voltage are detected behind the voltage regulator. The controller responds accordingly in time, which can solve the problem of sudden increase and decrease in voltage caused by load fluctuations. During the non-fracturing operation period, the local control strategy is executed. This strategy can protect the life of the equipment to a certain extent and avoid the reduction of the number of equipment lifespans caused by the gear adjustment, thereby ensuring the smooth construction of the project and reducing the maintenance cost of the equipment.

[0031] In other embodiments, further, Figure 1 and Figure 2 As shown, when the fracturing equipment starts to work, the power supply control system detects the voltage V and apparent power S at the input end of the fracturing equipment in real time through the CT PT mutual inductor; when the fracturing equipment is working, it is judged by the size of the apparent power S. When it is greater than the first set value, such as 300kVA, the power supply control system determines the load equipment and starts the fracturing operation stage; further detects the apparent power and the voltage V at the load end. When the apparent power is greater than the second set value, such as 500kva, it starts to issue a start-up instruction to the remote controller to execute the remote control strategy for the SVR system. When the apparent power increases to a certain value, and the grid voltage at the load end is less than the third set value, such as 10.3kV, the SVR system begins to prepare for automatic upshifting. The time for upshift switching is determined according to the voltage drop range at that time. An example is as follows:

[0032] 10~10.3kV, 60s to complete the gear shift;

[0033] 9.7-10kV, 30s to complete the gear shift;

[0034] 9.4~9.7kV, 15s to complete the gear shift;

[0035] 9.1~9.4kV, 10s to complete the gear shift;

[0036] After the upshift is completed, it is determined again whether the current grid voltage at the load end is less than the third set value (10.3kV). If it is less than, the upshift continues. If it is greater than 10.3kV and less than the fourth set value (10.8kV), the gear is maintained. When the voltage is higher than 10.8kV, the downshift is performed to keep the voltage between 10.3-10.8.

[0037] When the apparent power at the fracturing load end decreases, the voltage at the grid input end will increase, which in turn will cause the voltage at the load end to increase, thereby executing a downshift until the apparent power is less than the first set value (300kva). The remote control program is terminated, the operation is terminated, and the power supply control system sends and starts the local control program. The interval time between upshifting and downshifting is adjusted to the set value, for example, 120s, and the operation ends; the remote controller waits for the next fracturing operation.

[0038] It should be noted that within the scope of protection defined in the claims of the present invention, the following embodiments can be combined and / or expanded or replaced in any logical way from the above specific implementation methods, such as disclosed technical principles, disclosed technical features or implicitly disclosed technical features.

[0039] Example 1

[0040] A control method for regulating grid voltage during fracturing operation, in the fracturing process of oil and gas production, comprises the following steps:

[0041] During the fracturing operation of the fracturing equipment, a first control strategy is executed; the first control strategy is a remote control strategy, under which the controller responds accordingly in a timely manner by detecting changes in power and voltage behind the voltage regulator, so as to avoid sudden increases and decreases in voltage caused by load fluctuations;

[0042] During the non-fracture operation of the fracturing equipment, a second control strategy is executed; the second control strategy is a local control strategy, and the local control strategy is used to protect the equipment life and avoid a reduction in the equipment life due to gear adjustment.

[0043] Example 2

[0044] On the basis of Example 1, the remote control strategy detects the changes of power and voltage behind the voltage regulator, and the controller responds accordingly in time to avoid sudden increase and decrease of voltage caused by load fluctuation, which specifically includes the following sub-steps:

[0045] S1, when the fracturing equipment starts to work, the power supply control system detects the voltage V and apparent power S of the input end of the fracturing equipment in real time through the mutual inductor; when the apparent power S is greater than the first set value, the fracturing operation starts; otherwise, the operation ends;

[0046] S2, detecting the apparent power S and the voltage V at the load end, when the apparent power S is greater than the second set value, issuing a start command to the remote controller, and remotely controlling the SVR system through the remote controller, otherwise returning to step S1;

[0047] S3, when the apparent power S increases to a certain value and the grid voltage at the load end is less than the third set value, the SVR system starts to prepare for automatic upshifting;

[0048] S4, after the gear up is completed, it is determined again whether the current grid voltage at the load end is less than the third set value, if so, the gear up is continued; if so, the gear is maintained if it is greater than the third set value and less than the fourth set value;

[0049] S5, when the voltage is higher than the fourth set value, it will downshift to make the voltage between the third set value and the fourth set value; when the apparent power at the fracturing load end decreases, the voltage at the grid input end will increase, which will cause the voltage at the load end to increase, thereby performing a downshift until the apparent power is less than the first set value, ending the remote control program, ending the operation, and the power supply control system sends and starts the local control program, and the remote controller waits for the next fracturing operation.

[0050] Example 3

[0051] On the basis of Embodiment 2, in step S1, the transformer includes a 10kv CT transformer and a 10kv PT transformer.

[0052] Example 4

[0053] Based on Example 2, in step S1, the first set value is 300 kVA.

[0054] Example 5

[0055] On the basis of Example 2, in step S2, the second set value is 500 kva.

[0056] Example 6

[0057] Based on Example 2, in step S3, the third set value is 10.3 kV.

[0058] Example 7

[0059] Based on the second embodiment, in step S3, the time of upshift switching is determined according to the voltage drop range at that time.

[0060] Example 8

[0061] Based on Example 2, the fourth set value is 10.8 kV.

[0062] Example 9

[0063] A control device for regulating grid voltage during fracturing operations, comprising a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is loaded by the processor, the method described in any one of Examples 1 to 8 is executed.

[0064] Example 10

[0065] A control system for regulating grid voltage during fracturing operations, comprising the control device for regulating grid voltage during fracturing operations described in Example 9.

[0066] The units involved in the embodiments of the present invention may be implemented by software or hardware, and the units described may also be arranged in a processor. The names of these units do not, in some cases, limit the units themselves.

[0067] According to one aspect of an embodiment of the present invention, a computer program product or a computer program is provided, the computer program product or the computer program includes a computer instruction, and the computer instruction is stored in a computer-readable storage medium. A processor of a computer device reads the computer instruction from the computer-readable storage medium, and the processor executes the computer instruction, so that the computer device executes the method provided in the above various optional implementations.

[0068] As another aspect, an embodiment of the present invention further provides a computer-readable medium, which may be included in the electronic device described in the above embodiment; or may exist independently without being assembled into the electronic device. The above computer-readable medium carries one or more programs, and when the above one or more programs are executed by an electronic device, the electronic device implements the method described in the above embodiment.

Claims

1. A control method for regulating power grid voltage during fracturing operations, characterized in that: In the fracturing process of oil and gas production, the following steps are included: During the fracturing operation of the fracturing equipment, a first control strategy is executed; the first control strategy is a remote control strategy, under which the controller responds accordingly in a timely manner by detecting changes in power and voltage behind the voltage regulator, so as to avoid sudden increases and decreases in voltage caused by load fluctuations; During the non-fracture operation of the fracturing equipment, a second control strategy is executed; the second control strategy is a local control strategy, and the local control strategy is used to protect the equipment life and avoid a reduction in the equipment life due to gear adjustment.

2. The control method for regulating grid voltage during fracturing operation according to claim 1, characterized in that: The remote control strategy detects the power and voltage changes behind the voltage regulator, and the controller responds accordingly in time to avoid sudden increase and decrease of voltage caused by load fluctuation, which specifically includes the following sub-steps: S1, when the fracturing equipment starts to work, the power supply control system detects the voltage V and apparent power S of the input end of the fracturing equipment in real time through the mutual inductor; when the apparent power S is greater than the first set value, the fracturing operation starts; otherwise, the operation ends; S2, detecting the apparent power S and the voltage V at the load end, when the apparent power S is greater than the second set value, issuing a start command to the remote controller, and remotely controlling the SVR system through the remote controller, otherwise returning to step S1; S3, when the apparent power S increases to a certain value and the grid voltage at the load end is less than the third set value, the SVR system starts to prepare for automatic upshifting; S4, after the gear up is completed, it is determined again whether the current grid voltage at the load end is less than the third set value, if so, the gear up is continued; if so, the gear is maintained if it is greater than the third set value and less than the fourth set value; S5, when the voltage is higher than the fourth set value, it will downshift to make the voltage between the third set value and the fourth set value; when the apparent power at the fracturing load end decreases, the voltage at the grid input end will increase, which will cause the voltage at the load end to increase, thereby performing a downshift until the apparent power is less than the first set value, ending the remote control program, ending the operation, and the power supply control system sends and starts the local control program, and the remote controller waits for the next fracturing operation.

3. The control method for regulating grid voltage during fracturing operation according to claim 2, characterized in that: In step S1, the transformers include a 10kv CT transformer and a 10kv PT transformer.

4. The control method for regulating grid voltage during fracturing operation according to claim 2, characterized in that: In step S1, the first set value is 300 kVA.

5. The control method for regulating grid voltage during fracturing operation according to claim 2, characterized in that: In step S2, the second set value is 500 kva.

6. The control method for regulating grid voltage during fracturing operation according to claim 2, characterized in that: In step S3, the third set value is 10.3 kV.

7. The control method for regulating grid voltage during fracturing operation according to claim 2, characterized in that: In step S3, the time for upshifting is determined according to the voltage drop range at that time.

8. The control method for regulating grid voltage during fracturing operation according to claim 2, characterized in that: The fourth set value is 10.8 kV.

9. A control device for regulating power grid voltage during fracturing operations, characterized in that: The method comprises a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is loaded by the processor, the method according to any one of claims 1 to 8 is executed.

10. A control system for regulating power grid voltage during fracturing operations, characterized in that: The control device for regulating the voltage of the power grid during the fracturing operation is included in claim 9.

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