Pumping unit feed recovery method and system based on energy storage equipment

Abstract

The invention discloses a pumping unit feed recovery method based on energy storage equipment. The pumping unit feed recovery method comprises the following steps: S1, acquiring real-time power of an oil field power grid access point; s2, the real-time power of the oil pumping unit during working is obtained; s3, obtaining the residual capacity of an energy storage unit of the energy storage equipment; s4, setting an oil field power grid feed protection value; s5, calculating a power instruction of an energy storage converter according to the real-time power of the oil pumping unit during working and the residual capacity of an energy storage unit; s6, the energy storage converter carries out charging operation according to the power instruction to carry out feed absorption or carries out discharging operation to absorb the stored electric energy so as to reduce the power consumption of the oil field; s7, comparing the real-time power of the oil field power grid access point with a feed protection value to obtain a comparison result, and sending a feed adjustment instruction to an energy storage converter according to the comparison result; and S8, the energy storage converter adjusts the power of the energy storage converter in real time according to the feed adjustment instruction so as to adjust the power of the access point of the oil field power grid to prevent the feed phenomenon.

Description

Technical Field

[0001] This invention belongs to the field of oil pumping unit technology, specifically relating to a method and system for recovering power from an oil pumping unit based on an energy storage device. Background Technology

[0002] When pumping oil in oil fields, the pumping units currently used in many oil wells have problems such as poor balance and negative torque, which cause power loss during the pumping operation cycle.

[0003] Power feeding is harmful; if not controlled or recovered, it not only causes energy loss but also interferes with the power grid. Currently, the main methods to address power feeding are using variable speed motors and frequency converters to change the motor speed and reduce the degree of feeding, but these cannot completely eliminate the phenomenon. Another method is to use energy storage media such as capacitors to build a DC energy storage device on the power supply side to absorb and manage the power feeding. However, this requires the oilfield to have its own DC system, has poor applicability, is costly, and offers no additional benefits beyond power feeding, making it uneconomical. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned problems and provide a method and system for recovering energy from pumping unit power supply through real-time monitoring and control of the power supply network via an energy storage system. This not only reduces energy waste but also eliminates the adverse effects of pumping unit motor power supply problems on the power grid.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is: a method for recovering power from an oil pumping unit based on an energy storage device, comprising the following steps:

[0006] S1. Obtain the real-time power at the oilfield power grid access point;

[0007] S2. Obtain the real-time power of the pumping unit during operation;

[0008] S3. Obtain the remaining capacity of the energy storage unit of the energy storage device;

[0009] S4. Set the power supply protection value for the oilfield power grid;

[0010] S5. Calculate the power command of the energy storage converter based on the real-time power of the pumping unit during operation and the remaining capacity of the energy storage unit.

[0011] S6. The energy storage converter performs a charging operation according to the power command to absorb power or a discharging operation to consume the stored electrical energy and reduce the power consumption of the oil field.

[0012] S7. Compare the real-time power at the oilfield power grid access point with the power supply protection value to obtain a comparison result, and issue a power supply adjustment command to the energy storage converter based on the comparison result.

[0013] S8. The energy storage converter adjusts its power in real time according to the power supply regulation command, thereby regulating the power of the oilfield power grid connection point to prevent power supply failure.

[0014] Furthermore, the specific method for calculating the power command of the energy storage converter based on the real-time power of the pumping unit during operation and the remaining capacity of the energy storage unit in S5 includes:

[0015] S51. If the real-time power of the pumping unit is negative and the pumping unit is operating in a power-feeding state, a charging command is sent to the energy storage converter. The charging command is used to store electrical energy to absorb power feeding.

[0016] S52. If the real-time power of the pumping unit is positive and the pumping unit is operating in a power-consuming state, then the power command is calculated based on the remaining capacity of the energy storage unit. Specifically, if the remaining capacity of the energy storage unit is higher than a preset value, then a discharge command is sent to the energy storage converter. The discharge command is used to release the stored electrical energy and reduce the power consumption of the oil field to generate revenue. If the remaining capacity of the energy storage unit is not higher than the preset value, then a power maintenance command is sent to the energy storage converter without changing the current state and power value of the energy storage converter.

[0017] Furthermore, the calculation formula for the power command of the energy storage converter in S5 is: P0 = s * P1 + P2 * In the formula, P0 is the power command of the energy storage converter in kilowatts, P1 is the rated power of the energy storage converter in kilowatts, P2 is the real-time power of the pumping unit in kilowatts, and s is the charging / discharging state, assigned by a pre-set peak-valley time period strategy. If the current peak-valley time period strategy is discharging, s takes a constant of 1; if the current peak-valley time period strategy is charging, s takes a constant of -1; if the current peak-valley time period strategy has no command, s takes a constant of 0. Furthermore, if no peak-valley time period strategy is set, the value is assigned according to the remaining capacity of the energy storage unit. If the remaining capacity of the energy storage unit is greater than the preset value, it is in the discharging state, and s takes a constant of 1; if the remaining capacity of the energy storage unit is less than the preset value, it is in the charging state, and s takes a constant of -1; if the remaining capacity of the energy storage unit is the preset value, it is in the holding state, and s takes a constant of 0. The control loop transfer function is expressed as follows:

[0018] ;

[0019] In the formula This is the proportional gain coefficient, taken as a constant of 0.6. The resonant gain coefficient is taken as a constant of 40. The characteristic angular frequency is n, which takes values ​​of 1, 3, 5, ... The feature width is 0.707*. In the formula It is a complex variable.

[0020] Furthermore, in S7, the real-time power at the oilfield grid connection point is compared with the feeder protection value to obtain a comparison result. The specific method for issuing adjustment commands to the energy storage converter based on the comparison result includes: if the real-time power at the grid connection point is less than the preset feeder protection value, a negative power adjustment command is sent to the energy storage converter; if the real-time power at the grid connection point is not less than the preset feeder protection value, a power maintenance command is sent to the energy storage converter.

[0021] Furthermore, the calculation method for the adjustment command is as follows:

[0022] ΔP=k*(Pg-Pr), where ΔP is the adjustment command in kilowatts, Pg is the real-time power at the grid connection point in kilowatts, Pr is the feeder protection value in kilowatts, k is the adjustment ratio, which is a constant of 0.2. The calculation and transmission frequency of ΔP are synchronized and both are set to 200ms.

[0023] Furthermore, the negative power adjustment command is superimposed on the current control command of the energy storage converter to reduce the discharge power or increase the charging power; the power maintenance command does not change the current control command of the energy storage converter, ensuring the normal capacity regulation, backup power and peak shaving and valley filling functions of the energy storage system; the actual power command executed by the energy storage converter is P = P0 + ΔP, where P is the actual command executed by the energy storage converter in kilowatts, P0 is the power command of the energy storage converter in kilowatts, and ΔP is the adjustment command in kilowatts.

[0024] This invention also discloses a pumping unit power recovery system based on an energy storage device, comprising: a power grid, an energy storage device, and a pumping unit. The energy storage device includes an energy storage unit, an energy storage converter, a processor, and a power grid information acquisition device. The power grid information acquisition device is used to collect the real-time power of the pumping unit during operation and the real-time power of the oilfield power grid connection point, and transmits the real-time power of the pumping unit and the real-time power of the power grid to the processor. The energy storage unit transmits its remaining capacity data to the processor. The processor calculates a power command for the energy storage converter based on the real-time power of the pumping unit and the remaining capacity of the energy storage unit. The energy storage converter performs a charging operation to absorb power from the pumping unit or a discharging operation to dissipate the stored energy and reduce power consumption in the oilfield. A comparison result is obtained by comparing the real-time power of the oilfield power grid connection point with the power supply protection value, and a power supply adjustment command is issued to the energy storage converter based on the comparison result.

[0025] Preferably, the processor includes a computing unit and a control unit. The computing unit calculates the real-time power of each module, and the control unit is used to parse the real-time power of each module and the remaining capacity of the energy storage device to generate power commands, and issue specific power commands to the energy storage converter. Specifically, if the real-time power of the pumping unit is negative and the pumping unit is operating in a power-feeding state, a charging command is sent to the energy storage converter. The charging command is used to store electrical energy to absorb power feeding. If the real-time power of the pumping unit is positive and the pumping unit is operating in a power-consuming state, a power command is calculated based on the remaining capacity of the energy storage unit. Specifically, if the remaining capacity of the energy storage unit is higher than a preset value, a discharging command is sent to the energy storage converter. The discharging command is used to release the stored electrical energy and reduce the power consumption of the oil field to generate revenue. If the remaining capacity of the energy storage unit is not higher than the preset value, a power maintenance command is sent to the energy storage converter without changing the current state and power value of the energy storage converter.

[0026] Preferably, the control unit is a power supply control unit, which is used to compare the real-time power at the oilfield power grid connection point with the power supply protection value to obtain a comparison result, and issue a power supply adjustment command to the energy storage converter based on the comparison result.

[0027] The beneficial effects of this invention are:

[0028] 1. The present invention provides a method and system for recovering power from a pumping unit based on an energy storage device. This method and system recovers energy when the pumping unit is powered down, which not only reduces energy waste but also mitigates the adverse effects of pumping unit motor power failure on the power grid. Furthermore, it can generate additional economic benefits by peak shaving and valley filling during normal oil well operation and provide backup power when the oil well power grid is interrupted, thus achieving safe backup power and production assurance for the pumping unit.

[0029] 2. This invention solves the power supply problem generated during oil well pumping unit operation, as well as the power grid management problems caused by the power supply problem. At the same time, absorbing the power supply promotes energy conservation and emission reduction in oil wells, while peak shaving and valley filling reduce the production cost of oil wells, providing additional economic benefits to oil wells. The backup power guarantee function of the system also improves the reliability, stability and continuity of oil well operation. Attached Figure Description

[0030] Figure 1 This is a flowchart of a method for recovering power from an oil pumping unit based on an energy storage device, according to the present invention.

[0031] Figure 2 This is a schematic diagram of an oil pumping unit power recovery system based on an energy storage device according to the present invention.

[0032] Attached figures: 1. Power grid; 2. Energy storage device; 3. Energy storage unit; 4. Energy storage converter; 5. Oil pumping unit; 6. Processor; 7. Power grid information acquisition equipment. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0034] like Figure 1 As shown, the present invention provides a method for recovering power from an oil pumping unit based on an energy storage device, comprising the following steps:

[0035] S1. Obtain the real-time power of the oilfield power grid access point.

[0036] S2. Obtain the real-time power of the pumping unit during operation.

[0037] S3. Obtain the remaining capacity of the energy storage unit of the energy storage device.

[0038] S4. Set the power supply protection value for the oilfield power grid.

[0039] S5. Calculate the power command of the energy storage converter based on the real-time power of the pumping unit during operation and the remaining capacity of the energy storage unit.

[0040] The specific method for calculating the power command of the energy storage converter based on the real-time power of the pumping unit during operation and the remaining capacity of the energy storage unit in step S5 includes:

[0041] S51. If the real-time power of the pumping unit is negative and the pumping unit is operating in a power-feeding state, a charging command is sent to the energy storage converter. The charging command is used to store electrical energy to absorb power feeding.

[0042] S52. If the real-time power of the pumping unit is positive and the pumping unit is operating in a power-consuming state, then the power command is calculated based on the remaining capacity of the energy storage unit. Specifically, if the remaining capacity of the energy storage unit is higher than a preset value, a discharge command is sent to the energy storage converter. The discharge command is used to release the stored electrical energy, reducing the power consumption of the oilfield and generating revenue. If the remaining capacity of the energy storage unit is not higher than the preset value, a power maintenance command is sent to the energy storage converter, without changing the current state and power value of the energy storage converter.

[0043] The formula for calculating the power command of the energy storage converter in step S5 is: P0 = s * P1 + P2 * In the formula, P0 is the power command of the energy storage converter (in kilowatts), P1 is the rated power of the energy storage converter (in kilowatts), P2 is the real-time power of the pumping unit (in kilowatts), and s is the charging / discharging state, assigned by a pre-set peak-valley time period strategy. If the current peak-valley time period strategy is discharging, s takes a constant of 1; if the current peak-valley time period strategy is charging, s takes a constant of -1. If there is no command for the current peak-valley time period strategy, s takes a constant of 0. Furthermore, if no peak-valley time period strategy is set, the value is assigned according to the remaining capacity of the energy storage unit. If the remaining capacity of the energy storage unit is greater than the preset value, it is in a discharging state, and s takes a constant of 1. If the remaining capacity of the energy storage unit is less than the preset value, it is in a charging state, and s takes a constant of -1. If the remaining capacity of the energy storage unit is the preset value, it is in a holding state, and s takes a constant of 0. The control loop transfer function is expressed as follows:

[0044] ;

[0045] In the formula This is the proportional gain coefficient, taken as a constant of 0.6. The resonant gain coefficient is taken as a constant of 40. The characteristic angular frequency is n, which takes values ​​of 1, 3, 5, ... The feature width is 0.707*. In the formula It is a complex variable.

[0046] The energy storage converter can perform charging operations to absorb power from the grid according to the power command, or perform discharging operations to consume the stored electrical energy to reduce power consumption in the oil field, or maintain the current operating state.

[0047] The charging command should not exceed the transformer's allowable power limit to protect the transformer, and the power amplitude of the discharging command should not exceed the real-time power of the pumping unit to prevent power feeding at the grid end.

[0048] S6. The energy storage converter performs a charging operation according to the power command to absorb power or a discharging operation to consume the stored electrical energy and reduce the power consumption of the oil field.

[0049] S7. The comparison result is obtained by comparing the real-time power of the oilfield power grid access point with the power supply protection value, and the power supply adjustment command is sent to the energy storage converter according to the comparison result.

[0050] In step S7, the real-time power at the oilfield power grid connection point is compared with the feeder protection value to obtain a comparison result. The specific method for issuing adjustment commands to the energy storage converter based on the comparison result includes: if the real-time power at the power grid connection point is less than the preset feeder protection value, a negative power adjustment command is sent to the energy storage converter. If the real-time power at the power grid connection point is not less than the preset feeder protection value, a power maintenance command is sent to the energy storage converter.

[0051] The calculation method for the adjustment command is as follows:

[0052] ΔP=k*(Pg-Pr), where ΔP is the adjustment command in kilowatts, Pg is the real-time power at the grid connection point in kilowatts, Pr is the feeder protection value in kilowatts, k is the adjustment ratio, which is a constant of 0.2. The calculation and transmission frequency of ΔP are synchronized and both are set to 200ms.

[0053] The negative power regulation command is superimposed on the current control command of the energy storage converter, reducing the discharge power or increasing the charging power; the power maintenance command does not change the current control command of the energy storage converter, ensuring the normal capacity regulation, backup power, and peak shaving and valley filling functions of the energy storage system. The actual power command executed by the energy storage converter is P = P0 + ΔP, where P is the actual command executed by the energy storage converter in kilowatts, P0 is the power command of the energy storage converter in kilowatts, and ΔP is the regulation command in kilowatts.

[0054] S8. The energy storage converter adjusts its power in real time according to the power supply regulation command, thereby regulating the power of the oilfield power grid connection point to prevent power supply failure.

[0055] like Figure 2 As shown, this invention also discloses a pumping unit power recovery system based on an energy storage device, comprising: a power grid 1, an energy storage device 2, and a pumping unit 5. The energy storage device 2 includes an energy storage unit 3, an energy storage converter 4, a processor 6, and a power grid information acquisition device 7. The power grid information acquisition device 7 is used to collect the real-time power of the pumping unit during operation and the real-time power of the oilfield power grid connection point, and transmits the real-time power of the pumping unit and the real-time power of the power grid to the processor 6. The energy storage unit 3 transmits its remaining capacity data to the processor 6. The processor 6 calculates the power command for the energy storage converter based on the real-time power of the pumping unit and the remaining capacity of the energy storage unit 3, and issues the power command to the energy storage converter 4. The energy storage converter 4 performs a charging operation to absorb power from the pumping unit or a discharging operation to dissipate the stored energy and reduce power consumption in the oilfield. A comparison result is obtained by comparing the real-time power of the oilfield power grid connection point with the power supply protection value, and a power supply adjustment command is issued to the energy storage converter based on the comparison result.

[0056] The processor 6 includes a computing unit and a control unit. The computing unit calculates the real-time power of each module, and the control unit parses the real-time power of each module and the remaining capacity of the energy storage device to generate power commands. It then sends specific power commands to the energy storage converter 4. Specifically, if the real-time power of the pumping unit is negative and the pumping unit 5 is operating in a power-feeding state, a charging command is sent to the energy storage converter. This charging command is used to store electrical energy to absorb power. If the real-time power of the pumping unit is positive and the pumping unit 5 is operating in a power-consuming state, the power command is calculated based on the remaining capacity of the energy storage unit 3. Specifically, if the remaining capacity of the energy storage unit 3 is higher than a preset value, a discharging command is sent to the energy storage converter 4. This discharging command is used to release the stored electrical energy, reducing the oilfield's power consumption and generating revenue. If the remaining capacity of the energy storage unit 3 is not higher than the preset value, a power maintenance command is sent to the energy storage converter 4, without changing the current state and power value of the energy storage converter 4.

[0057] The control unit is a power supply control unit. The power supply control unit is used to compare the real-time power at the oilfield power grid connection point with the power supply protection value to obtain the comparison result, and send the power supply adjustment command to the energy storage converter 4 according to the comparison result.

[0058] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention, and should be understood that the scope of protection of the invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed in this invention without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of this invention.

Claims

1. A method for recovering power supplied to a pumping unit based on an energy storage device, characterized by, The method comprises the following steps: S1, acquiring real-time power of an oilfield power grid access point; S2, acquiring real-time power of the pumping unit during operation; S3, acquiring residual capacity of an energy storage unit of the energy storage device; S4, setting an oilfield power grid feeding protection value; S5, calculating a power instruction of the energy storage converter according to the real-time power of the pumping unit during operation and the residual capacity of the energy storage unit; S6, the energy storage converter performs charging operation according to the power instruction to absorb feeding or performs discharging operation to consume stored electric energy and reduce oilfield power consumption; S7, comparing the real-time power of the oilfield power grid access point with the feeding protection value to obtain a comparison result, and sending a feeding adjustment instruction to the energy storage converter according to the comparison result; S8, the energy storage converter adjusts the power of the energy storage converter in real time according to the feeding adjustment instruction, thereby adjusting the power of the oilfield power grid access point to prevent feeding phenomenon.

2. The method of claim 1, wherein the energy storage device is a battery. The specific method of calculating the power instruction of the energy storage converter in S5 comprises: S51, if the real-time power of the pumping unit is negative and the pumping unit operates in a feeding state, a charging instruction is sent to the energy storage converter, and the charging instruction is used to store electric energy to absorb feeding; S52, if the real-time power of the pumping unit is positive and the pumping unit operates in a power consumption state, a power instruction is calculated according to the residual capacity of the energy storage unit, specifically, if the residual capacity of the energy storage unit is higher than a preset value, a discharging instruction is sent to the energy storage converter, and the discharging instruction is used to release stored electric energy to reduce oilfield power consumption and generate benefits; if the residual capacity of the energy storage unit is not higher than the preset value, a power maintaining instruction is sent to the energy storage converter, without changing the current state and power value of the energy storage converter.

3. The method of claim 1, wherein the energy storage device is a battery. The calculation formula of the energy storage converter power instruction in S5 is: P0=s*P1+P2 , wherein, P0 is the energy storage converter power instruction, unit: kilowatt, P1 is the energy storage converter rated power, unit: kilowatt, P2 is the real-time power of the pumping unit, unit: kilowatt, s is the charging and discharging state, which is assigned by the pre-set peak-valley period strategy, if the current peak-valley period strategy is discharging, s takes constant 1; if the current peak-valley period strategy is charging, s takes constant-1; if the current peak-valley period strategy has no instruction, s takes constant 0; further, if the peak-valley period strategy is not set, the remaining capacity of the energy storage unit is assigned, if the remaining capacity of the energy storage unit is greater than the pre-set value, it is in the discharging state, s takes constant 1; if the remaining capacity of the energy storage unit is less than the pre-set value, it is in the charging state, s takes constant-1; if the remaining capacity of the energy storage unit is the pre-set value, it is in the maintaining state, s takes constant 0; is the control loop transfer function, and its expression is: ； wherein is a proportional gain coefficient, taking the constant value 0.6, is a resonant gain coefficient, taking the constant value 40, is a characteristic angular frequency, n taking the values 1, 3, 5,... is a characteristic width, taking the value 0.707 wherein is a complex variable.

4. The method of claim 1, wherein the energy storage device is a battery. The specific method of comparing the real-time power of the oilfield power grid access point with the feeding protection value to obtain a comparison result and sending an adjustment instruction to the energy storage converter in S7 comprises: if the real-time power of the power grid access point is less than the preset feeding protection value, a negative power adjustment instruction is sent to the energy storage converter; if the real-time power of the power grid access point is not less than the preset feeding protection value, a power maintaining instruction is sent to the energy storage converter.

5. The method of claim 4, wherein the energy storage device is a battery. The calculation method of the adjustment instruction is: ΔP=k*(Pg-Pr), wherein ΔP is the adjustment instruction, with a unit of kilowatt, Pg is the real-time power of the power grid access point, with a unit of kilowatt, Pr is the feeding protection value, with a unit of kilowatt, k is an adjustment proportion, which is a constant of 0.2, and the calculation of ΔP is synchronous with the sending frequency, both of which are set to 200 ms.

6. The method of claim 4, wherein the energy storage device is a battery. The negative power adjustment instruction is superimposed on the current control instruction of the energy storage converter to reduce discharging power or increase charging power; the power maintaining instruction does not change the current control instruction of the energy storage converter to ensure normal capacity adjustment, standby power supply and peak load shifting functions of the energy storage system; and the actual execution power instruction of the energy storage converter is P=P0+ΔP, wherein P is the actual execution instruction of the energy storage converter, with a unit of kilowatt, P0 is the power instruction of the energy storage converter, with a unit of kilowatt, and ΔP is the adjustment instruction, with a unit of kilowatt.

7. A pumped hydroelectric system based on the recovery of power from a pumping unit, characterized in that, The method comprises: The power grid (1), the energy storage device (2) and the pumping unit (5), the energy storage device (2) includes an energy storage unit (3), an energy storage converter (4), a processor (6) and a power grid information acquisition device (7), wherein the power grid information acquisition device (7) is used to acquire the real-time power of the pumping unit during operation and the real-time power of the oilfield power grid access point, and transmit the real-time power data of the pumping unit and the real-time power data of the power grid to the processor (6); the energy storage unit (3) transmits its remaining capacity data to the processor (6); the processor (6) calculates the energy storage converter power instruction according to the real-time power of the pumping unit and the remaining capacity of the energy storage unit (3); the energy storage converter (4) performs charging operation according to the power instruction to absorb power feeding or discharging operation to consume stored electric energy to reduce oilfield power consumption; the real-time power of the oilfield power grid access point is compared with the power feeding protection value to obtain a comparison result, and a power feeding adjustment instruction is sent to the energy storage converter according to the comparison result.

8. A pumped hydroelectric system according to claim 7, wherein, The processor (6) includes a calculation unit and a control unit, the calculation unit calculates the real-time power of each module, and the control unit is used to analyze the real-time power of each module and the remaining capacity of the energy storage device to generate a power instruction, and send a specific power instruction to the energy storage converter (4), specifically including: if the real-time power of the pumping unit is negative and the pumping unit (5) is working in the power feeding state, a charging instruction is sent to the energy storage converter, and the charging instruction is used to store electric energy to absorb power feeding; if the real-time power of the pumping unit is positive and the pumping unit (5) is working in the power consumption state, a power instruction is calculated according to the remaining capacity of the energy storage unit (3), specifically, if the remaining capacity of the energy storage unit (3) is higher than a preset value, a discharging instruction is sent to the energy storage converter (4), and the discharging instruction is used to release stored electric energy to reduce oilfield power consumption and generate benefits; if the remaining capacity of the energy storage unit (3) is not higher than the preset value, a power retention instruction is sent to the energy storage converter (4), without changing the current state and power value of the energy storage converter (4).

9. A pumped hydroelectric system according to claim 8, wherein, The control unit is a power feeding control unit, which is used to compare the real-time power of the oilfield power grid access point with the power feeding protection value to obtain a comparison result, and send a power feeding adjustment instruction to the energy storage converter (4) according to the comparison result.

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