Oilfield drilling winch brake energy feedback and energy storage integrated control method and system

Abstract

The application discloses a kind of oil field drilling winch brake energy feedback energy storage integrated control method and system, it is related to oil field drilling mechanical equipment electrical control technical field, including: winch is in braking condition;When direct current side voltage is greater than or equal to the set feedback starting voltage threshold and less than the set feedback energy storage voltage threshold, and alternating current side voltage is less than or equal to the set alternating voltage threshold, brake energy is converted and fed back to power grid;When direct current side voltage is greater than or equal to the feedback energy storage voltage threshold, or alternating current side voltage is greater than alternating voltage threshold, the remaining brake energy is stored until braking ends or direct current side voltage drops to the set optimal operating voltage threshold, release the brake energy stored and converted and fed back to power grid;Wherein, voltage double-loop vector control strategy is used to adjust inverter feedback power in the process of conversion and feedback. Realize the collaborative control of brake energy feedback and energy storage buffer, and consider power quality management of power grid.

Description

Technical Field

[0001] This invention relates to the field of electrical control technology for oilfield drilling machinery and equipment, and in particular to an integrated control method and system for brake energy feedback and energy storage of oilfield drilling winches. Background Technology

[0002] Oilfield drilling winches are the core power equipment of drilling rig systems, mainly used for raising and lowering drill strings, suspending drill strings, and controlling drilling pressure. In a normal drilling cycle, the raising and lowering of drill strings alternate, and the entire process involves enormous potential energy. At a well depth of 4,000 meters, the potential energy power can reach the megawatt level, resulting in a high proportion of energy consumption.

[0003] Currently, oilfield drilling winches use frequency converters to drive AC motors. During the lowering of the drill string, the motor is in a regenerative braking state, generating a large amount of regenerative energy. This regenerative energy is generally consumed as heat by braking resistors, which not only wastes energy but also causes problems such as heat dissipation and space occupation. The process of putting on / off the braking resistors causes drastic fluctuations in the DC bus voltage, affecting the safe operation of the frequency converter and other equipment; frequent load changes can also impact the power supply.

[0004] Currently, some improvement schemes attempt to introduce energy feedback devices to feed braking energy back to the power grid. However, existing feedback control strategies do not set reasonable feedback thresholds based on the operating characteristics of drilling winches. Either the energy feedback is too low due to unreasonable threshold settings, resulting in the energy saving effect not meeting expectations, or excessive feedback affects the stability of the DC bus voltage, interfering with the normal braking control of the drilling winch. This leads to large bus voltage fluctuations, low feedback efficiency, and insufficient harmonic suppression capabilities, making it impossible to achieve the synergistic optimization effect of energy feedback and power quality management, and making it difficult to adapt to the complex and ever-changing operating conditions of oilfield drilling. Summary of the Invention

[0005] To address the aforementioned issues, this invention proposes an integrated control method and system for brake energy feedback and energy storage of oilfield drilling winches. By controlling the feedback power, it achieves coordinated control of brake energy feedback and energy storage buffering. Under the premise of ensuring stable and reliable winch braking, it maximizes the recovery of potential energy generated by braking and converts it into electrical energy to feed back to the power grid, thereby improving the energy-saving effect of oilfield drilling operations while also taking into account the power quality management of the power grid.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides an integrated control method for brake energy feedback and energy storage of oilfield drilling winches, comprising: Obtain the DC and AC voltages when the winch is in braking condition; When the DC side voltage is greater than or equal to the set feedback start voltage threshold and less than the set feedback energy storage voltage threshold, and the AC side voltage is less than or equal to the set AC voltage threshold, the braking energy is inverted and fed back to the grid. When the DC side voltage is greater than or equal to the feedback energy storage voltage threshold, or the AC side voltage is greater than the AC voltage threshold, the remaining braking energy is stored until braking ends or the DC side voltage drops to the set optimal operating voltage threshold, at which point the stored braking energy is released and fed back to the grid via inverter. In the process of inverter feedback, the voltage compensation amount is determined based on the voltage difference between the feedback start voltage threshold and the optimal operating voltage threshold. Combined with the inverter modulation waveform, active current command, and harmonic and reactive current compensation amounts, the inverter feedback power is adjusted.

[0007] As an alternative implementation, when the DC side voltage is less than the feedback start voltage threshold, only power quality management is performed, and braking energy feedback is not performed.

[0008] As an alternative implementation, the voltage compensation amount is superimposed on the peak value of the inverter modulation waveform to adjust the inverter output signal.

[0009] As an alternative implementation, the voltage compensation amount is superimposed on the active current command, which includes converting the braking energy power corresponding to the winch braking into an active current reference and then superimposing the voltage compensation amount.

[0010] As an alternative implementation, the voltage compensation amount is superimposed on the harmonic and reactive current compensation amounts, including receiving power quality control commands, which are three-phase currents and three-phase voltages on the AC side, extracting harmonics and reactive currents from the power quality control commands, thereby generating compensation amounts of equal amplitude and opposite phase, and superimposing the voltage compensation amount.

[0011] In a second aspect, the present invention provides an integrated control system for brake energy feedback and energy storage of oilfield drilling winches, comprising: a control unit and an inverter feedback unit and an energy storage unit connected to the control unit; The control unit is configured to: Obtain the DC and AC voltages when the winch is in braking condition; When the DC side voltage is greater than or equal to the set feedback start voltage threshold and less than the set feedback energy storage voltage threshold, and the AC side voltage is less than or equal to the set AC voltage threshold, the inverter feedback unit is started to invert and feed the braking energy back to the grid through the inverter feedback unit. When the DC side voltage is greater than or equal to the feedback energy storage voltage threshold, or the AC side voltage is greater than the AC voltage threshold, the control starts the energy storage unit. The remaining braking energy can be stored through the energy storage unit until the braking ends or the DC side voltage drops to the set optimal operating voltage threshold, at which point the stored braking energy is released and inverted back to the grid. In the process of inverter feedback, the voltage compensation amount is determined based on the voltage difference between the feedback start voltage threshold and the optimal operating voltage threshold. Combined with the inverter modulation waveform, active current command, and harmonic and reactive current compensation amounts, the inverter feedback power is adjusted.

[0012] As an alternative implementation, the inverter feedback unit includes a connected capacitor bank and a three-phase voltage-source PWM inverter. The capacitor bank is connected to a fuse through an anti-reverse diode. The fuse is connected to the DC side of the winch frequency converter. The three-phase voltage-source PWM inverter is connected to the grid side to realize the unidirectional flow of winch braking energy and to invert the winch braking energy into AC power with the same frequency and phase as the grid before feeding it back to the grid.

[0013] As an alternative implementation, the energy storage unit includes a bidirectional DC / DC converter and a supercapacitor bank connected together; the bidirectional DC / DC converter is connected to a fuse via an anti-reverse diode, and the fuse is connected to the DC side of the winch frequency converter.

[0014] As an alternative implementation, the control system is connected to the positive and negative terminals of the DC side of the winch frequency converter via fuses FU1 and FU2, respectively; fuse FU1 is connected to the positive terminal of the anti-reverse diode D1, fuse FU2 is connected to the negative terminal of the anti-reverse diode D2, and the negative terminal of the anti-reverse diode D1 and the positive terminal of the anti-reverse diode D2 are connected to the control system.

[0015] Thirdly, the present invention provides an electronic device including a memory, a processor, and computer instructions stored in the memory and running on the processor. When executed by the processor, the computer instructions implement the method described in the first aspect.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention proposes an integrated control method and system for braking energy feedback and energy storage in oilfield drilling winches. When the DC-side voltage is greater than or equal to a set feedback start-up voltage threshold but less than a set feedback energy storage voltage threshold, and the AC-side voltage is less than or equal to a set AC voltage threshold, the braking energy is inverted and fed back to the grid. When the DC-side voltage is greater than or equal to the feedback energy storage voltage threshold, or the AC-side voltage is greater than the AC voltage threshold, the remaining braking energy is stored. By introducing an energy storage buffer mechanism, the system can automatically switch to energy storage mode when feedback is limited or the grid is abnormal, effectively avoiding sudden rises in bus voltage and grid impacts, ensuring system safety and improving power quality. During the inverter feedback process, a closed-loop vector control strategy is used to dynamically adjust the feedback power, optimize the inverter output waveform, reduce harmonic content, and smooth DC bus voltage fluctuations. This improves energy feedback efficiency while ensuring power quality, enhancing system stability and braking safety. Furthermore, this invention features a compact system structure and flexible control, eliminating the need for additional large-capacity braking resistors, significantly reducing equipment size and maintenance costs, and demonstrating significant economic benefits and broad engineering application prospects.

[0017] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1 This is a topology diagram of the integrated control system for brake energy feedback and energy storage of oilfield drilling winches provided in Embodiment 1 of the present invention; Figure 2 This is a feedback energy flow diagram provided in Embodiment 1 of the present invention; Figure 3 Here is a flowchart of the dual closed-loop vector control strategy provided in Embodiment 1 of the present invention; Figure 4 This is a flowchart of the dual closed-loop vector control command provided in Embodiment 1 of the present invention; Figure 5 The feedback waveform trend diagram provided in Embodiment 1 of the present invention. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0022] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. Furthermore, it should be understood that the terms “comprising” and “including”, and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0023] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0024] Example 1 like Figure 1 As shown, this embodiment provides an integrated control system for energy feedback and storage of oilfield drilling winch braking energy, realizing integrated energy recovery and reuse. The system is connected to the positive and negative terminals of the winch frequency converter's DC side via fuses FU1 and FU2, respectively. Fuse FU1 is connected to the positive terminal of anti-reverse diode D1, and fuse FU2 is connected to the negative terminal of anti-reverse diode D2. The negative terminal of anti-reverse diode D1 and the positive terminal of anti-reverse diode D2 are connected to the system, allowing energy to flow unidirectionally through the anti-reverse diodes, thus drawing the winch braking energy into the system. After passing through the system's bidirectional converter, the DC power is inverted into AC power, which is then connected to the power grid via the injection reactor L. Finally, the circuit breaker QF feeds the winch braking energy back to the AC power grid, improving system stability.

[0025] In this embodiment, the system mainly includes an inverter feedback unit, an energy storage unit, a control unit, and a human-machine interface unit.

[0026] Specifically: (1) The inverter feedback unit connects the DC bus to the power grid. Its AC side is connected to the power grid side through the power grid connection unit, and its DC side is connected to the DC side of the winch frequency converter through the fuse and anti-reverse diode, so as to realize the unidirectional flow of the winch braking energy and convert the DC bus power into AC power with the same frequency and phase as the power grid, and after filtering out high frequency harmonics, it is connected to the power grid.

[0027] Specifically, it includes a connected capacitor bank and three-phase voltage-source PWM inverters Q1-Q6. The capacitor bank includes capacitors C1 and C2 connected in series.

[0028] One end of the capacitor bank is connected to the negative terminal of the anti-reverse diode D1, the positive terminal of the anti-reverse diode D1 is connected to the fuse FU1, and the fuse FU1 is connected to the positive terminal of the DC side of the winch frequency converter. The other end of the capacitor bank is connected to the positive terminal of the anti-reverse diode D2, the negative terminal of the anti-reverse diode D2 is connected to the fuse FU2, and the fuse FU2 is connected to the negative terminal of the DC side of the winch frequency converter. The three-phase voltage-source PWM inverter is connected to the grid side through the grid connection unit.

[0029] The grid connection unit includes a reactor L connected to the three-phase voltage-source PWM inverter and a circuit breaker QF connected to the reactor L and used for grid connection, in order to filter out high-order harmonics generated during inverter feedback and ensure electrical isolation and safety protection on the grid side.

[0030] (2) The energy storage unit includes connected bidirectional DC / DC converters Q7-Q10 and a supercapacitor bank; One input terminal of the bidirectional DC / DC converter is connected to the negative terminal of the anti-reverse diode D1, the positive terminal of the anti-reverse diode D1 is connected to the fuse FU1, and the fuse FU1 is connected to the positive terminal of the DC side of the winch frequency converter. The other input terminal of the bidirectional DC / DC converter is connected to the positive terminal of the anti-reverse diode D2, the negative terminal of the anti-reverse diode D2 is connected to the fuse FU2, and the fuse FU2 is connected to the negative terminal of the DC side of the winch frequency converter.

[0031] As an energy buffer, the energy storage unit absorbs excess electrical energy and assists in energy storage when the grid's capacity is insufficient or the instantaneous feedback power is too large; when the grid feedback is obstructed, it releases energy to maintain the stability of the DC bus voltage and ensure the continuous and reliable operation of the system.

[0032] (3) The control unit is connected to the inverter feedback unit, the energy storage unit and the human-machine unit respectively, and is also connected to the signal acquisition unit.

[0033] The signal acquisition unit is used to acquire real-time voltage and current signals on the DC side of the winch frequency converter, and can also acquire AC side voltage and frequency, which are transmitted to the control unit to provide real-time feedback data to ensure that the inverter output is accurately synchronized with the power grid.

[0034] The control unit stores preset feedback voltage thresholds, judges the braking state based on the collected voltage and current signals, generates coordinated control commands for the energy storage unit and the inverter feedback unit, dynamically adjusts the power distribution between the energy storage unit and the inverter feedback unit, controls the magnitude and direction of the feedback power, ensures that the DC bus voltage is always maintained within a safe and stable range, and inverts the DC power generated by the winch braking into AC power that meets the grid requirements, which is then transmitted to the grid through the grid connection unit, realizing efficient recovery of braking energy and smooth grid connection.

[0035] (4) The human-machine unit is used to provide local status display and parameter setting interface, support operation data recording and fault alarm prompts, so that on-site operation and maintenance personnel can keep abreast of the system's operating status and make necessary interventions.

[0036] like Figure 2 As shown, under normal operating conditions, the DC bus voltage Udc on the DC side of the inverter is DC860V, the feedback start voltage Ufeed threshold is DC1200V, and energy flows in one direction. By comparing the real-time AC grid voltage Uac at the monitoring point with the rated AC grid voltage UacN (AC600V), and comparing the real-time DC bus current signal with the allowable rated DC current, closed-loop feedback is performed to control the feedback current, thereby regulating the power and keeping the system operating at the optimal DC side operating voltage threshold Uopt (e.g., DC900V), thus improving the system's optimal operating performance.

[0037] In this embodiment, as Figure 3 - Figure 4 As shown, the control method of the above system includes the following steps: (1) Integrate power quality management and feedback energy storage into a single control unit. The control unit stores the preset optimal operating voltage threshold Uopt of the winch frequency converter DC side, the feedback start-up voltage threshold Ufeed (e.g., DC1200V), and the feedback energy storage voltage threshold Ubat. in (e.g., DC1250V), and the feedback energy storage voltage threshold Ubat in is greater than the feedback start-up voltage threshold Ufeed.

[0038] Specifically, when the DC-side voltage is greater than or equal to the feedback start-up voltage threshold Ufeed, the inverter feedback unit (DC / AC) is activated to invert energy and feed it back to the grid; during the feedback process, when the voltage rises to a level greater than or equal to the feedback energy storage voltage threshold Ubat... When the voltage drops to the optimal operating voltage threshold Uopt, the stored energy is fed back to the grid.

[0039] (2) Real-time acquisition of DC side voltage Udc and current Idc, AC side voltage Uac and current Iac, to determine the winch operating status.

[0040] When the winch is in the hoisting state, it needs to draw power from the grid and is in a power-consuming state. The AC current Iac collected by the AC side monitoring point is greater than the preset AC threshold (e.g., 20A), and the DC side voltage Udc is about 860V.

[0041] When the winch is in braking mode, it is in generator mode. The AC side current is negative, and the DC side voltage will rise until it rises to the feedback start voltage threshold, after which braking energy feedback will occur.

[0042] (3) When the winch is in braking condition, the optimal operating voltage threshold Uopt, the feedback start voltage threshold Ufeed, and the feedback energy storage voltage threshold Ubat are combined. in performs braking energy feedback and storage.

[0043] Specifically: When the motor enters the power generation mode, it generates regenerative electrical energy (i.e., braking energy), which causes the DC bus voltage to gradually increase.

[0044] When the detected DC-side voltage Udc is less than the feedback start-up voltage threshold Ufeed, only power quality management is performed, and braking energy feedback is not performed.

[0045] When the DC side voltage Udc is greater than or equal to the feedback start-up voltage threshold Ufeed and less than the feedback energy storage voltage threshold Ubat When the AC side voltage Uac is less than or equal to the set AC voltage threshold, the inverter feedback unit is activated, and the inverter feedback unit is controlled to feed the braking energy back to the grid.

[0046] Meanwhile, a voltage dual closed-loop vector control strategy is adopted to dynamically adjust the inverter feedback power, ensuring that the voltage on the AC side and DC side is within a reasonable range during feedback, thereby matching the winch braking torque requirements (i.e., consistency of dynamic inertia or without affecting the mechanical characteristics of the winch), and ensuring a smooth and reliable braking process.

[0047] (4) When the DC side voltage Udc is greater than or equal to the feedback energy storage voltage threshold Ubat When the AC side voltage Uac is greater than the AC voltage threshold, it will automatically switch to the energy storage buffer mode.

[0048] At this time, the control unit generates a command to start the bidirectional DC / DC converter, which stores the excess regenerated electrical energy exceeding the direct feedback capacity into the supercapacitor bank, smooths out DC bus voltage fluctuations, and prevents voltage over-limit from affecting the safe operation of the equipment.

[0049] In this embodiment, the DC / AC power capacity can be preset, and any excess power is stored in the supercapacitor via DC / DC converter. Alternatively, during feedback, the DC bus voltage exceeds Ubat. The "in" indicates that the rated power of the DC / AC circuit cannot meet the actual demand, and more power is needed. Therefore, excess braking energy is stored and fed back when the voltage drops. Alternatively, if the AC voltage feedback power is too high, the AC voltage will rise when the AC system consumes less power. Generally, it exceeds the AC grid rated voltage UacN (AC600V) by 5%, i.e., AC630V (the AC voltage threshold). In this case, some braking energy is stored to ensure the AC voltage does not exceed AC630V, thus improving the system's power supply safety.

[0050] (5) After the braking process ends or the DC bus voltage drops back to the safe range (i.e., reduced to the optimal operating voltage threshold Uopt), the bidirectional DC / DC converter is controlled to release the stored electrical energy and feed it back to the grid through the inverter feedback unit, thereby smoothing the DC bus voltage fluctuation, avoiding insufficient feedback power causing the bus voltage to rise sharply, and ensuring the safe operation of the system.

[0051] It also detects the AC side voltage. When the AC side voltage exceeds the allowable deviation range of the AC side grid rated voltage, that is, when the AC side voltage exceeds the AC voltage threshold, the feedback power is limited and the electrical energy is stored in the energy storage unit to prevent abnormal rise in AC side grid voltage.

[0052] In this embodiment, the adjustment of inverter feedback power adopts a voltage dual closed-loop vector control strategy to drive the inverter feedback unit and the bidirectional DC / DC unit, so as to achieve precise energy feedback and perform AC and DC side voltage and current status feedback to achieve closed-loop acquisition.

[0053] Specifically, it includes: (1) During the drilling tool lowering braking process, the DC side bus voltage and AC side voltage are monitored in real time, and the feedback power is dynamically adjusted to ensure stable operation under different working conditions.

[0054] The voltage compensation amount is generated based on the voltage difference ΔU between the feedback start-up voltage threshold Ufeed and the optimal operating voltage threshold Uopt.

[0055] (2) The voltage compensation is superimposed on the peak value of the inverter modulation waveform to adjust the inverter output signal.

[0056] As one implementation method, an SPWM modulation ratio value is generated based on the voltage difference ΔU, and the command signal for feedback power is fed back proportionally. The larger ΔU is, the greater the voltage compensation is. When ΔU is 0, the starting value and the ideal value are dynamically consistent and no adjustment is made.

[0057] For example, the instruction is divided into 512 points in a 20-millisecond cycle, with each point being 39 microseconds. The instruction is superimposed at 5 milliseconds and 15 milliseconds in each cycle (0-20 milliseconds) to improve bus utilization, optimize the sinusoidal nature of the AC current output of the inverter, and reduce the current distortion rate.

[0058] (3) Add the voltage compensation amount to the active current command.

[0059] The regenerative feedback power corresponding to the winch braking obtained after judging each threshold is converted into an active current reference, and closed-loop feedback is received. The voltage compensation signal is superimposed to perform closed-loop regulation and correction of the active current command.

[0060] (4) Simultaneously receive power quality control commands to synchronously superimpose harmonic and reactive power compensation control quantities.

[0061] The power quality control command is the three-phase current and voltage values ​​on the AC side. The fundamental wave is removed by instantaneous reactive power theory. Based on the remaining reactive power and harmonic values, a compensation command with equal amplitude and opposite phase is generated to cancel the reactive power and harmonics detected on the grid side.

[0062] Specifically: The active power command i is obtained by transforming the three-phase voltage and three-phase current into vector coordinates. d reactive power instruction i q The harmonic command is obtained after the DC component is separated by a low-pass filter. , ; will have active instruction i d reactive power instruction i q Harmonic command , Superimpose the active power i absorbed by the energy storage stg Remove it from the load current and inject a current that is opposite in phase to the load harmonics to cancel the distortion; remove the fundamental reactive power. The compensation is zero to improve the power factor. Then, it is dynamically adjusted according to the target power quality. The adjusted command is PWM modulated, and the superimposed dq command is inversely transformed to the abc three-phase stationary coordinate system.

[0063] (5) After the three types of instructions are synchronously superimposed and converted and regulated by vector coordinate transformation, SPWM instruction modulation and other signal conversion, the output inverter feedback unit drive signal is generated. The braking energy is converted into electrical energy and fed back to the grid through the inverter feedback unit. The feedback energy is maximized under the premise of ensuring the stability of the bus voltage. At the same time, closed-loop feedback sampling is performed to realize the automatic adjustment of the feedback power. The grid side harmonic control and reactive power compensation are completed throughout the process to ensure the power quality of the power supply.

[0064] like Figure 5As shown, to further illustrate the collaborative working mechanism of each unit, on-site test data is used as evidence. Test data shows that under the condition of deceleration from 1500 r / min to 1400 r / min, the system's peak regenerative power reaches 609 kW, with a braking time of only 3 seconds, verifying the system's rapid response capability and high power density advantage under high-frequency braking conditions. Furthermore, under the conditions of deceleration from 1100 r / min to 0 r / min and from 1100 r / min to 500 r / min, the system also exhibits excellent braking performance, with regenerative power reaching 469 kW and 459 kW respectively, and braking times of 6 seconds and 5 seconds respectively. Purple represents DC voltage, red represents DC current, green represents AC current, and yellow represents AC voltage, fully demonstrating that the system can achieve efficient and stable energy recovery under different deceleration conditions.

[0065] In further embodiments, the following is also provided: An electronic device includes a memory and a processor, as well as computer instructions stored in the memory and running on the processor, which, when executed by the processor, implement the method described in Embodiment 1. For brevity, further details are omitted here.

[0066] It should be understood that in this embodiment, the processor can be a central processing unit (CPU), or it can be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc.

[0067] Memory can include read-only memory and random access memory, providing instructions and data to the processor. A portion of the memory may also include non-volatile random access memory. For example, memory may also store information about the device type.

[0068] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. An integrated control method for brake energy feedback and energy storage in oilfield drilling winches, characterized in that, include: Obtain the DC and AC voltages when the winch is in braking condition; When the DC side voltage is greater than or equal to the set feedback start voltage threshold and less than the set feedback energy storage voltage threshold, and the AC side voltage is less than or equal to the set AC voltage threshold, the braking energy is inverted and fed back to the grid. When the DC side voltage is greater than or equal to the feedback energy storage voltage threshold, or the AC side voltage is greater than the AC voltage threshold, the remaining braking energy is stored until braking ends or the DC side voltage drops to the set optimal operating voltage threshold, at which point the stored braking energy is released and fed back to the grid via inverter. In the process of inverter feedback, the voltage compensation amount is determined based on the voltage difference between the feedback start voltage threshold and the optimal operating voltage threshold. Combined with the inverter modulation waveform, active current command, and harmonic and reactive current compensation amounts, the inverter feedback power is adjusted.

2. The integrated control method for brake energy feedback and energy storage of oilfield drilling winches as described in claim 1, characterized in that, When the DC side voltage is less than the feedback start voltage threshold, only power quality management is performed, and braking energy feedback is not performed.

3. The integrated control method for brake energy feedback and energy storage of oilfield drilling winches as described in claim 1, characterized in that, The voltage compensation is superimposed on the peak value of the inverter modulation waveform to adjust the inverter output signal.

4. The integrated control method for brake energy feedback and energy storage of oilfield drilling winches as described in claim 1, characterized in that, The voltage compensation is added to the active current command, which includes converting the braking energy power corresponding to the winch braking into an active current reference and then adding the voltage compensation.

5. The integrated control method for brake energy feedback and energy storage of oilfield drilling winches as described in claim 1, characterized in that, The voltage compensation is superimposed on the harmonic and reactive current compensation. This includes receiving power quality control commands, which are the three-phase current and three-phase voltage on the AC side. Harmonics and reactive current are extracted from the power quality control commands to generate compensation with equal amplitude and opposite phase, and then superimposed on the voltage compensation.

6. An integrated control system for brake energy feedback and energy storage in oilfield drilling winches, characterized in that: include: The control unit, and the inverter feedback unit and energy storage unit connected to the control unit; The control unit is configured to: Obtain the DC and AC voltages when the winch is in braking condition; When the DC side voltage is greater than or equal to the set feedback start voltage threshold and less than the set feedback energy storage voltage threshold, and the AC side voltage is less than or equal to the set AC voltage threshold, the inverter feedback unit is started to invert and feed the braking energy back to the grid through the inverter feedback unit. When the DC side voltage is greater than or equal to the feedback energy storage voltage threshold, or the AC side voltage is greater than the AC voltage threshold, the control starts the energy storage unit. The remaining braking energy can be stored through the energy storage unit until the braking ends or the DC side voltage drops to the set optimal operating voltage threshold, at which point the stored braking energy is released and inverted back to the grid. In the process of inverter feedback, the voltage compensation amount is determined based on the voltage difference between the feedback start voltage threshold and the optimal operating voltage threshold. Combined with the inverter modulation waveform, active current command, and harmonic and reactive current compensation amounts, the inverter feedback power is adjusted.

7. The integrated control system for brake energy feedback and energy storage of oilfield drilling winches as described in claim 6, characterized in that, The inverter feedback unit includes a connected capacitor bank and a three-phase voltage-source PWM inverter. The capacitor bank is connected to a fuse through a reverse protection diode. The fuse is connected to the DC side of the winch frequency converter. The three-phase voltage-source PWM inverter is connected to the grid side to realize the unidirectional flow of winch braking energy and to invert the winch braking energy into AC power with the same frequency and phase as the grid before feeding it back to the grid.

8. The integrated control system for brake energy feedback and energy storage of oilfield drilling winches as described in claim 6, characterized in that, The energy storage unit includes a bidirectional DC / DC converter and a supercapacitor bank connected together; the bidirectional DC / DC converter is connected to a fuse via an anti-reverse diode, and the fuse is connected to the DC side of the winch frequency converter.

9. The integrated control system for brake energy feedback and energy storage of oilfield drilling winches as described in claim 7 or 8, characterized in that, The control system is connected to the positive and negative terminals of the DC side of the winch frequency converter through fuses FU1 and FU2 respectively; fuse FU1 is connected to the positive terminal of the anti-reverse diode D1, fuse FU2 is connected to the negative terminal of the anti-reverse diode D2, and the negative terminal of the anti-reverse diode D1 and the positive terminal of the anti-reverse diode D2 are connected to the control system.

10. An electronic device, characterized in that, It includes a memory and a processor, as well as computer instructions stored in the memory and running on the processor, which, when executed by the processor, implement the method as described in any one of claims 1-5.

Images