Control method and control system of linear motor submersible reciprocating drainage device

Abstract

This invention relates to the field of oil extraction technology, specifically disclosing a control method and system for a linear motor submersible reciprocating drainage device. The control method includes: reading and initializing preset operating parameters after power-on; cyclically collecting downhole pressure, temperature, fluid level, and motor current signals, filtering them, and then uploading them; determining the target stroke count and speed based on real-time operating data and target deviation using a PID and fuzzy control fusion algorithm; controlling motor operation with closed-loop speed regulation at the target speed; generating a high-speed jet at a pre-set unblocking speed during a preset phase; intermittently stopping after each stroke, starting a new cycle after the cumulative stroke count reaches the target; real-time monitoring and execution of safety protection; and support for local and remote control. The system includes modules for parameter management, data acquisition and communication, decision control, motor drive and control, cycle management, and safety monitoring and protection. This invention achieves intelligent control, improves drainage efficiency, and has the advantages of automatic unblocking and high reliability.

Description

Technical Field

[0001] This application relates to the field of oil extraction technology, and in particular to a control method and control system for a linear motor submersible reciprocating oil extraction device. Background Technology

[0002] In the field of oil extraction, intelligent control of downhole oil production equipment is crucial for achieving supply-demand coordination and energy conservation.

[0003] Chinese Patent, Publication No. CN104331001A, Publication Date: February 4, 2015, discloses a fuzzy control method for a submersible electric pump. This method uses the bottom hole pressure collected in real time by a downhole pressure monitoring device as input, calculates the required frequency through a fuzzy control algorithm, and then adjusts the frequency converter driving the rotary motor to change the speed of the submersible centrifugal pump.

[0004] The drawback of the above technical solution is that it only uses the "bottom hole pressure" deviation and its rate of change as the control input. Under complex deep well reciprocating pumping conditions, it is difficult to comprehensively and accurately judge the downhole fluid supply capacity, pump efficiency, rod and tubing friction, and whether blockage (such as perforation blockage) occurs based solely on the pressure signal. This results in insufficient adaptive capability and control precision of the control system when facing complex nonlinear and strongly coupled conditions. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this application is to provide a control method and control system for a linear motor submersible reciprocating oil drainage device. This system utilizes a multi-parameter sensing and adaptive decision-making intelligent closed-loop control method to achieve efficient, reliable, and energy-saving reciprocating drainage operations.

[0006] To achieve the above objectives, this application adopts the following technical solution: This application provides a control method for a linear motor submersible reciprocating oil extraction device, the control method comprising the following steps: S101 After the control system is powered on, it reads the preset operating mode parameters, target stroke parameters, upward speed parameters, downward speed parameters and target liquid level depth parameters from the non-volatile memory, and completes the initialization configuration of each hardware module of the control system. S102 uses an analog-to-digital converter to cyclically collect downhole pressure signals, temperature signals, liquid level signals, and motor current signals at a preset frequency. It filters the collected multiple consecutive sampling points and uploads them after encapsulation and verification according to a preset communication protocol. S103, based on the deviation between the real-time collected operating data and the target parameters, combined with the preset operating mode, uses a PID and fuzzy control fusion algorithm to determine the target stroke, target upward speed, and target downward speed of the current sampling and discharge cycle. S104, during the upward or downward phase of the motor, uses the target speed determined by the decision as the set value and the speed calculated in real time as the feedback value for adjustment, and dynamically outputs drive signals to control the linear motor to run according to the preset commutation logic. S105, during the preset phase of the motor's downward stroke, controls the motor's mover to complete a stroke at a preset unblocking speed higher than the discharge speed, so as to generate a high-speed jet; S106, after a single upward and downward stroke is completed, the motor enters a preset intermittent stop phase; after the cumulative number of completed strokes reaches the current target number of strokes, the control system enters a new mining and discharge cycle; S107 monitors motor current, temperature and communication status in real time. When any monitored data is compared with the corresponding protection threshold and a fault is triggered, the control system immediately executes emergency stop protection and records the fault information. S108, the control system supports local manual control mode and remote automatic control mode; in remote automatic control mode, the control system receives and parses remote commands to update operating parameters, and automatically executes the closed-loop process from parameter acquisition to stroke control.

[0007] As a preferred technical solution, step S101 includes: The control system, centered on a DSP chip, first reads pre-stored parameters such as operating mode, target stroke, uplink speed, downlink speed, and target liquid level depth from the non-volatile memory area of ​​the DSP chip's EEPROM. Subsequently, the control system initializes the analog-to-digital converter module, timer module, PWM drive module, and serial communication module sequentially. The analog-to-digital converter module is configured for multi-channel cyclic sampling mode, the timer module is set as the base clock for generating the motor commutation and control cycle, the PWM module is set to complementary output mode to drive the subsequent IGBT power bridge, and the serial communication module is initialized... The baud rate is preset to prepare for data exchange; a parameter verification mechanism is integrated during the parameter loading stage, which determines whether the various parameter values ​​read from the EEPROM are within the preset reasonable threshold range. If a parameter value exceeds the limit, the recovery program is automatically called to reset the parameter value to a safe default value and rewrite it to the EEPROM; after all hardware modules are initialized, the control system performs a self-test operation covering all key output ports and status indicator lights, and generates a status message containing the control system version, loading parameters and self-test results, which is uploaded through the serial communication module, thus completing the complete startup process from static parameter loading to dynamic function readiness.

[0008] As a preferred technical solution, step S102 includes: The control system uses the ADC module built into the DSP chip as its core, configured in a multi-channel cyclic sampling mode. It sequentially acquires analog signals from the motor current, tubing pressure, casing pressure, and temperature sensors at a fixed sampling frequency. For each channel, the control system executes a digital filtering algorithm, continuously acquiring several raw data points within one sampling cycle. The arithmetic mean of these raw data points is then calculated and used as the valid sample value for that sampling cycle. The acquisition of the analog signals from the motor current, tubing pressure, casing pressure, and temperature sensors is completed within a preset data update cycle, and all analog signals acquired within the same data update cycle are assigned a uniform label. Timestamp; The processed data is organized into message frames conforming to the Modbus-RTU format. Before transmission, the CRC-16 checksum of the frame data is calculated and appended to the end of the message, and then transmitted through the RS-232 serial physical interface; Hardware noise isolation circuit is introduced at the ADC sampling front end, and recursive median filtering is used at the software level to suppress sudden spike interference; The validity of the analog signals of motor current, oil pipe pressure, casing pressure and temperature sensors is continuously monitored. If the analog signal is continuously out of range or disconnected, the abnormal state is marked in the data frame, and the valid data of the previous cycle or the default safety value is temporarily replaced according to the preset strategy.

[0009] As a preferred technical solution, step S103 includes: The control system uses the real-time acquired deviation between the liquid level depth and the target liquid level depth, as well as the pressure difference between the casing pressure and the tubing pressure, as core input variables. The preset operating mode determines the priority of the control target. In local manual or remote automatic mode, the preset stroke and speed are directly adopted. In liquid level control mode, an adaptive decision-making process is initiated. In liquid level control mode, the core decision-making employs a two-stage algorithm that integrates PID control and fuzzy control. The first stage is a fuzzy decision-maker, which fuzzifies the two precise quantities—liquid level deviation and pressure difference—into linguistic variables including "negative large," "negative small," "zero," "positive small," and "positive large," and outputs adjustments to the target stroke and target speed based on a pre-set expert experience rule base. The first level consists of a factor; the second level is a parameter self-tuning PID controller, which uses the adjustment factor output by the previous level fuzzy decision-maker as a real-time correction quantity to dynamically fine-tune the proportional, integral, and derivative coefficients of the PID controller; the second-level algorithm, which integrates PID control and fuzzy control, outputs three sets of decision values ​​for the optimal target stroke, target upward speed, and target downward speed within the current production and drainage cycle; the second-level algorithm, which integrates PID control and fuzzy control, includes a performance evaluation module, which compares the actual liquid level change rate after one decision cycle with the expected change rate, and adaptively optimizes the weights of some rules in the fuzzy rule base with a small step size based on the comparison results, so that the control system can slowly approach the optimal control strategy for a specific oil well.

[0010] As a preferred technical solution, step S104 includes: The control system obtains the target upward speed and target downward speed from the decision in step S103, and uses them as the set values ​​for their respective motion directions. The speed feedback value is obtained by measuring the motor commutation cycle through a high-precision timer and calculating it in real time, forming a closed-loop control speed feedback loop. The core controller uses a PID algorithm to calculate and output the duty cycle of the PWM signal used to drive the IGBT power bridge in real time by performing proportional, integral, and derivative operations on the deviation between the set value and the feedback value. Feedforward compensation is introduced into the PID algorithm, that is, the load disturbance of the current stroke is predicted based on the historical data of current and pressure of the previous stroke, and the PWM duty cycle is compensated and adjusted in advance. The PWM drive module outputs signals in a complementary manner, controlling the IGBT's on and off in an orderly manner through preset commutation logic, thereby driving the linear motor's mover to run at a constant speed. The commutation logic is strictly triggered by a hardware timer interrupt to ensure the accuracy of the commutation timing. To prevent integral term saturation and control failure during startup, shutdown, or when encountering obstacles, the PID algorithm incorporates an anti-integral saturation mechanism, automatically freezing the integral action when the output PWM duty cycle reaches the limit value. The control system integrates a state observer in the speed loop, using motor current and back EMF information to perform soft measurement of the actual speed, serving as a redundancy check and smoothing filter for encoder or timer speed measurement methods.

[0011] As a preferred technical solution, step S105 includes: At the end of the motor's downward stroke, when the mover position enters the preset unblocking trigger range, the control system initiates the jet unblocking control sequence. The unblocking trigger is dynamically determined by the intelligent decision module, based on real-time monitoring of the production rate decline trend, downhole pressure fluctuation characteristics, and historical unblocking records. Triggering only occurs when a comprehensive assessment indicates a risk of perforation blockage. After the unblocking sequence is initiated, the control system immediately switches the motor's downward speed from the current drainage speed to the preset high-speed unblocking speed. During the high-speed downward phase, the control system uses high-precision position estimation or sensor feedback to control the mover to complete a fixed short stroke at the unblocking speed. At the end of the high-speed stroke, the control logic includes a brief pressure stabilization phase to allow the fluid kinetic energy to fully act on the blockage before transitioning to the normal shutdown or reversal process. After each unblocking action, the control system enters a monitoring period, tracking pressure and production rate changes in the subsequent drainage cycles. By comparing the operating data before and after unblocking, the system automatically evaluates the unblocking effect and uses the evaluation results to learn and optimize the trigger threshold and speed parameters for the next unblocking operation.

[0012] As a preferred technical solution, step S106 includes: The control system precisely manages stroke timing through hardware timer interrupts. Upon completion of a single upward or downward stroke, the motor control state is immediately switched to an intermittent stop phase, and an independent stop timer begins accumulating time. The duration of the intermittent stop is dynamically calculated by the core algorithm, based on the current target number of strokes, target speed, and real-time estimated downhole fluid supply capacity. During the stop phase, the control system shuts down all IGBT drive signals, placing the motor in a free state, but maintains the acquisition of all sensor data and fault monitoring logic. Simultaneously, a dedicated stroke counter accumulates the completed effective strokes. When the stroke count reaches the target stroke count for the current cycle, it marks the end of a complete sampling and output cycle. First, the control system executes the cycle switching routine, which includes summarizing and evaluating the operating data of the previous cycle, and fine-tuning the target parameters or interval time of the next cycle based on the evaluation results, to achieve incremental optimization between cycles. Subsequently, the control system resets the stroke counter and stop timer, and decides on the latest operating mode to enter the next sampling and output cycle, restarting the cycle from step S102. During the intermittent stop phase, the control system automatically adjusts the power of the auxiliary circuit or enters a low-power monitoring mode until the next action command is triggered.

[0013] As a preferred technical solution, step S107 includes: The control system implements multi-dimensional parallel monitoring. Motor phase current is sampled by Hall effect sensors and converted into digital values ​​by an ADC module, then compared in real-time with overcurrent protection thresholds. Motor winding and downhole ambient temperatures are collected by PT1000 sensors, also converted by an ADC, and compared with over-temperature protection thresholds. Communication status is comprehensively evaluated through serial interface bit error rate statistics, response timeout counters, and CRC check failure counts. A background learning algorithm periodically fine-tunes the overcurrent and over-temperature protection thresholds based on historical motor operating load, ambient temperature baseline, and equipment aging trends. When any monitored data exceeds its dynamic threshold, the control system... The system immediately triggers the highest priority fault interrupt. The fault interrupt first unconditionally blocks the PWM drive signals of all IGBTs and controls the relay to cut off the main power circuit, realizing a hardware-level emergency shutdown. At the same time, the control system packages the specific fault type code, the snapshot data of the fault moment, and the current operating parameters into a timestamped encrypted fault record, which is saved to a dedicated sector of non-volatile memory. The control system integrates a predictive maintenance mechanism based on trend analysis. The predictive maintenance mechanism continuously analyzes indicators including current harmonics and temperature rise rate to identify potential risks before physical thresholds are exceeded and reports early warning information in advance.

[0014] As a preferred technical solution, step S108 includes: The control system defines and manages operating modes through the values ​​of core variables. In local manual mode, the control system only responds to button operations on the MCGS configuration screen connected locally to the controller and actively blocks any control commands from the remote communication port. In remote automatic mode, the control system continuously monitors the network through a serial communication interface, receives and parses remote command frames conforming to the Modbus-RTU format. After CRC verification and authentication, the target parameters contained in the remote command frames are temporarily stored in the receive buffer variable. Subsequently, the control system, through a parameter synchronization mechanism, compares the valid parameters in the receive buffer with the current operating parameters while ensuring security. If there is a change, the system will automatically update the receiving buffer. After secondary confirmation, the operating parameters are updated and immediately written to EEPROM for persistent storage. After the parameters are updated, the control system can automatically and seamlessly connect to the new control logic without restarting, and continue to execute the closed-loop control process from steps S102 to S107 according to the new target parameters. During remote control, if a local emergency stop signal is detected, the control system will immediately suspend the execution of the remote command sequence, prioritize the response to local safety commands, and support recovery from the breakpoint or restart according to the preset strategy after the fault is cleared. The control system can automatically maintain the last set of valid parameters before the interruption and continue to operate when remote communication is interrupted, and automatically report the operation log and synchronization status after communication is restored.

[0015] This application also provides a control system for a linear motor submersible reciprocating oil drainage device, the control system comprising: The parameter management module is used to read preset operating parameters from non-volatile memory after the control system is powered on, and supports receiving and parsing remote commands to update the operating parameters; The data acquisition and communication module is used to cyclically acquire downhole working condition signals at a preset frequency, and upload the acquired signals after filtering and protocol encapsulation. The decision control module is used to determine the target number of strokes and target running speed for the current mining and discharge cycle based on the deviation between the real-time collected operating data and the target parameters, combined with the preset operating mode, through the control algorithm. The motor drive and control module is used to perform closed-loop speed regulation with the target speed determined as the set value during the upward or downward phase of the motor, and output drive signals to control the linear motor to run according to preset logic, and to control the motor to run at the unblocking speed to generate high-speed jet during the preset phase. The cycle management module is used to control the motor to enter the intermittent stop phase after a single stroke is completed, and to start a new mining cycle after the cumulative number of strokes reaches the target number of strokes; The safety monitoring and protection module is used to monitor the system status in real time. When the monitored data triggers a fault, it immediately executes emergency shutdown protection and records the fault information.

[0016] Compared with the prior art, the beneficial effects of this application are as follows: 1. Achieved intelligent perception and decision-making through multi-parameter fusion: By cyclically collecting multi-dimensional signals such as pressure, temperature, liquid level, and current in step S102, and combining them with the PID and fuzzy control fusion algorithm in step S103 for decision-making, the control system can perceive the complex working conditions downhole more comprehensively, thereby outputting more reasonable target stroke and target speed, and improving the system's adaptive capability and control accuracy.

[0017] 2. Provides proactive downhole maintenance function: The unique "jet unblocking control" in step S105 enables the device to automatically generate high-speed jets at the end of the downward stroke, effectively cleaning the perforation and solving the problem of easy blockage in low-production wells.

[0018] 3. A complete closed-loop management and safety system has been established: the intermittent stop and periodic control in step S106 optimizes supply and demand coordination; the real-time monitoring and emergency protection in step S107 significantly improve system reliability; and the local / remote dual-mode control in step S108 enhances the system's operational flexibility. The entire solution forms a complete closed loop from parameter acquisition, intelligent decision-making, precise execution to safety protection and mode management, significantly improving the overall efficiency, reliability, and intelligence level of the linear motor submersible reciprocating oil extraction device. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating the steps of the control method for the linear motor submersible reciprocating oil extraction device of this application. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present application, the technical solutions in specific embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0021] like Figure 1 As shown, this application provides a control method for a linear motor-driven submersible reciprocating pumping device. The core of this control method lies in constructing a complete control process based on multi-source information perception, intelligent fusion decision-making, and closed-loop precise execution, so as to achieve efficient, reliable, and adaptive control of this special lifting device, a linear motor-driven plunger pump.

[0022] Step S101: System initialization and parameter loading.

[0023] After the control system is powered on, it reads the preset operating mode parameters, target stroke parameters, upward speed parameters, downward speed parameters, and target liquid level depth parameters from the non-volatile memory, and completes the initialization configuration of each hardware module of the control system.

[0024] In its implementation, the control system uses a TI TMS320F28335 DSP chip as its core processor. Upon power-up, the DSP first reads various key operating parameters pre-programmed by engineers from its integrated EEPROM non-volatile memory. These parameters include: operating mode (e.g., 1 represents local manual, 4 represents remote level control), target stroke rate (e.g., 5 strokes per minute), target upward speed (e.g., 0.6 m / s), target downward speed (e.g., 0.5 m / s), and target level depth (e.g., 1500 meters downhole). Subsequently, the control system initializes and configures the analog-to-digital converter (ADC) module, enhanced pulse width modulation (ePWM) module, enhanced capture (eCAP) module, and serial communication interface (SCI) in sequence. The ADC module is configured for sequential sampling mode to cyclically acquire signals from multiple sensors; the ePWM module is set to complementary output with dead-time control to safely drive the subsequent IGBT power bridge; the eCAP module is used to accurately measure motor commutation signals; and the SCI module is initialized to a specific baud rate (e.g., 9600bps) to prepare for communication with a host computer or remote monitoring center. During the parameter loading phase, the system integrates a parameter verification mechanism. For example, it checks whether the target impulse value is within a reasonable range of 1-20 impulses / minute. If the value is 25, it is considered out of range, and the system automatically calls a recovery program to reset the parameter to a default safe value (e.g., 5 impulses / minute) and rewrite it back to the EEPROM to prevent dangerous system operation due to memory damage. After all hardware modules are initialized, the control system will perform a self-test, cyclically illuminate all status indicator lights, read the levels of key output ports, and finally generate a status message containing the software version number, a list of loaded parameters, and the self-test result (such as "ADC module initialization OK"). This message is then uploaded through the SCI module, marking the completion of the entire startup process from static parameter loading to dynamic function readiness.

[0025] The beneficial effects of this step are: 1. Ensure stable system startup: By reliably loading historical setting parameters from non-volatile memory, combined with comprehensive hardware initialization and self-test, a stable and repeatable starting point is provided for subsequent control.

[0026] 2. Preventing misoperation and data corruption: The integrated parameter verification and recovery mechanism can effectively avoid parameter corruption caused by memory failure or abnormal power failure, thus improving the robustness of the system.

[0027] Step S102: Multi-parameter collaborative acquisition and preprocessing.

[0028] The analog-to-digital converter module cyclically collects downhole pressure signals, temperature signals, fluid level signals, and motor current signals at a preset frequency. The collected samples from multiple consecutive sampling points are filtered and then encapsulated and verified according to a preset communication protocol before being uploaded.

[0029] In practical implementation, the control system utilizes the 12-bit high-precision ADC module built into the DSP chip, configured in a multi-channel cyclic sampling mode. The system sequentially acquires six analog signals within one cycle: motor U, V, and W phase currents, tubing pressure, casing pressure, and downhole temperature, at a fixed sampling frequency of 1kHz. For each channel, to suppress random noise, the system executes a digital filtering algorithm: 64 raw data points are continuously acquired, summed, and their arithmetic mean is calculated. This average is used as the valid sample value for that channel in the current sampling cycle (1 millisecond). To achieve synchronization of multi-parameter data, these six signals complete one round of acquisition within a master control cycle (e.g., 10 milliseconds), and all data acquired within these 10 milliseconds are timestamped. The processed data is organized into message frames conforming to the industry-standard Modbus-RTU slave protocol. Before transmission, the system calculates the cyclic redundancy check (CRC-16) code for the frame data and appends it to the end of the message, then sends it through the RS-485 serial physical interface (which has stronger anti-interference capabilities). To further enhance reliability in the harsh electromagnetic environment of the mine, a hardware noise isolation circuit consisting of ferrite beads and filter capacitors was introduced into the ADC sampling front-end circuit design. At the software level, a recursive median filtering algorithm was also used for the current signal to suppress sudden spike interference. The system continuously monitors the signals from each sensor. If a signal (such as a temperature signal) is detected to be continuously exceeding the sensor's range (e.g., displaying -50℃ or 200℃) or disconnected (signal voltage constantly at 0), the channel is marked as "abnormal" in the configured data frame. Based on a preset strategy, the control logic temporarily uses the valid data from the previous cycle or a preset safety default value to replace the data, ensuring that the control loop is not interrupted.

[0030] The beneficial effects of this step are: 1. Provides highly reliable data sources: Through multiple means such as high-frequency sampling, mean filtering, hardware isolation, and software secondary filtering, noise interference is greatly suppressed, ensuring that the operating condition data used for decision-making is true and reliable.

[0031] 2. Ensure data timeliness and synchronization: Timestamp multi-dimensional data collected in the same period to ensure that data such as pressure, liquid level, and current have a strict time correspondence, laying an accurate foundation for subsequent integrated intelligent decision-making.

[0032] 3. Achieve strong anti-interference communication: Employ CRC checksum and RS-485 differential transmission to effectively ensure the accuracy and integrity of data transmission in long-distance, highly interference-prone downhole environments.

[0033] Step S103, Intelligent Fusion Decision Making.

[0034] Based on the deviation between the real-time collected operating data and the target parameters, and combined with the preset operating mode, the target stroke, target upward speed, and target downward speed of the current sampling and discharge cycle are determined by a fusion algorithm of PID and fuzzy control.

[0035] In specific implementation, the control system uses the deviation e between the real-time liquid level depth (MCGS_YMSD) and the target liquid level depth (EE_YMSD) obtained in step S102, and the pressure difference ΔP between the casing pressure (P_casing) and the tubing pressure (P_tubing) as core input variables. The preset operating mode (EE_RUN) determines the control priority. If the mode is local manual (EE_RUN=1) or remote fixed-rate (EE_RUN=4), the preset stroke count (EE_CC) and speed (EE_VH, EE_VL) are directly adopted. If it is remote liquid level control mode (EE_RUN=5), the adaptive decision-making process is entered. In this mode, a two-level decision-making algorithm combining PID control and fuzzy control is used. The first stage is a fuzzy decision-maker, which fuzzifies the precise liquid level deviation e (in meters) and pressure difference ΔP (in megapascals) into linguistic variables such as "negative large (NB)," "negative small (NS)," "zero (ZO)," "positive small (PS)," and "positive large (PB)" using quantization factors (e.g., Ke=0.1, KΔP=2). It then infers based on a pre-defined expert rule base. For example, a rule could be: "IFeisPBANDΔPisPS, THEN stroke adjustment factor isNBAND speed adjustment factor isNS," meaning "If the liquid level is much higher than the target and the pressure difference is slightly positive, then significantly reduce the stroke rate and slightly reduce the speed." The second stage is a parameter self-tuning PID controller, which uses the adjustment factors output by the previous stage fuzzy decision-maker as real-time corrections to dynamically fine-tune its proportional (Kp), integral (Ki), and derivative (Kd) coefficients. For example, when the fuzzy decision-maker outputs an adjustment factor indicating "need to speed up the response," the Kp value of the PID controller will be increased appropriately. Ultimately, this fusion algorithm outputs the optimal set of decision values ​​for the current production and drainage cycle: target stroke count N, target upward velocity V_up, and target downward velocity V_down. Furthermore, the algorithm's embedded performance evaluation module compares the actual liquid level change rate after one decision cycle (e.g., 1 hour) with the algorithm's expected change rate. If the actual recovery rate continues to be slower than expected, the weight of the relevant rules in the fuzzy rule base for "increasing stroke count" will be slowly increased in very small increments (e.g., 0.01), enabling the system to autonomously learn and approximate the optimal control strategy for that specific oil well.

[0036] The beneficial effects of this step are: 1. High control precision and strong adaptability: The fusion algorithm combines the advantages of fuzzy control in handling nonlinearity and uncertainty with the advantages of PID control in high steady-state precision, enabling the system to respond intelligently to complex and ever-changing downhole conditions and achieve precise and stable control.

[0037] 2. Possesses self-learning and optimization capabilities: The performance evaluation module provides feedback on the control effect and fine-tunes the rule weights, enabling the system to gradually adapt to the production dynamics of specific oil wells and achieve efficiency optimization under long-term operation.

[0038] Step S104: Speed ​​loop closed-loop control and execution.

[0039] During the upward or downward movement of the motor, the target speed determined by the decision is used as the set value, and the speed calculated in real time is used as the feedback value for adjustment. The dynamic output drive signal controls the linear motor to operate according to the preset commutation logic.

[0040] In practice, the control system obtains the target upward speed V_up and target downward speed V_down from the decision in step S103, which are used as the setpoints for the motor's upward and downward motion directions, respectively. The speed feedback value is calculated in real time by measuring the period of the motor's commutation Hall signal using a high-precision timer, thus forming a closed-loop control speed feedback loop. The core controller uses a digital PID algorithm to dynamically calculate the required duty cycle in real time by performing proportional, integral, and derivative operations on the deviation between the setpoint and the feedback value, and outputs the corresponding six pulse width modulation (PWM) signals to drive the IGBT power bridge. To cope with sudden load changes, feedforward compensation is introduced into the standard PID algorithm. For example, based on the current peak value when the previous stroke is close to the top dead center, the system predicts similar resistance that may be encountered in the current stroke and slightly increases the PWM duty cycle in advance to compensate for the slower speed. The PWM drive module outputs six signals in a complementary manner, and controls the conduction and cutoff of the six IGBTs in an orderly manner through a preset "six-step commutation" logic, thereby driving the mover of the permanent magnet synchronous linear motor to reciprocate at a constant speed. The commutation logic is strictly triggered by a hardware timer interrupt, ensuring timing accuracy down to the microsecond level. To prevent excessive accumulation (saturation) of the integral term during startup, shutdown, or encountering resistance, which could lead to control failure, the PID algorithm incorporates an anti-integral saturation mechanism: when the calculated PWM duty cycle reaches a hardware limit (e.g., 95%), the integral action is automatically frozen until the duty cycle exits the saturation region. Furthermore, a Luneburg observer is integrated into the speed loop. Using the acquired motor current and estimated back EMF information, it performs a "soft measurement" of the actual speed of the mover. This observation serves as a redundancy check and smoothing filter for Hall sensor speed measurement, further improving the stability and reliability of the control.

[0041] The beneficial effects of this step are: 1. Smooth operation and fast response: The linear motor adopts closed-loop PID control combined with feedforward compensation, which enables it to maintain the set speed and run smoothly when facing changing downhole loads, with good dynamic response performance.

[0042] 2. Precise and reliable drive: The six-step commutation logic based on hardware timer interrupts ensures the precise timing of the motor drive, while protection mechanisms such as anti-integral saturation improve the robustness of the controller and prevent loss of steps or overshoot.

[0043] Step S105, Adaptive jet unblocking control.

[0044] During the preset phase of the motor's downward stroke, the motor's actuator is controlled to complete a certain stroke at a preset unblocking speed higher than the discharge speed, so as to generate a high-speed jet.

[0045] In practice, at the end of the motor's downward stroke, when the position of the mover is confirmed by position estimation or sensors to be within the "unblocking trigger zone" of 0.3 meters from the bottom dead center, the control system initiates the jet unblocking control sequence. Unblocking triggering is not timed but dynamically determined by an intelligent decision-making module. This module's determination is based on: a continuous downward trend in production volume over multiple cycles, abnormal downhole pressure fluctuations (such as periodic micro-pulsations in casing pressure), and the time interval since the last unblocking action. Triggering only occurs when a comprehensive assessment indicates a risk of perforation blockage. Once the unblocking sequence is initiated, the control system immediately switches the motor's downward speed from the current production speed (e.g., 0.5 m / s) to a preset high-speed unblocking speed (e.g., 1.0 m / s). During the high-speed downward phase, the control system uses high-precision position estimation to control the mover to complete a fixed short stroke of 0.2 meters at a speed of 1.0 m / s. At the moment the high-speed stroke ends and the mover is about to stop, the control logic includes a brief pressure stabilization phase of approximately 0.1 seconds, allowing the high-pressure fluid kinetic energy generated within the pump chamber to fully act on the blockage at the perforation orifice. Subsequently, the system transitions to the normal shutdown or reversal process. After each unblocking action, the system enters a monitoring period lasting several hours, tracking the production volume and pressure recovery over the subsequent pumping cycles. By comparing data before and after unblocking, the system automatically evaluates the unblocking effectiveness (e.g., "effective," "moderately effective," "ineffective") and uses the evaluation results for learning and optimization: for example, if the unblocking effectiveness is "moderate," the trigger threshold for the next unblocking will become more sensitive, or the unblocking speed may be slightly increased.

[0046] The beneficial effects of this step are: 1. Enables automated downhole maintenance: Cleaning of perforated holes can be automatically completed through program control without the need for pump start-up, effectively solving the problem of easy blockage in low-production wells and sand-producing wells.

[0047] 2. Intelligent triggering, energy saving and high efficiency: Based on multi-parameter dynamic determination of the timing of blockage removal, unnecessary frequent high-speed operation is avoided. It only acts when needed, which not only ensures the effect but also saves energy.

[0048] Step S106: Optimize intermittent and periodic management.

[0049] After a single upward and downward stroke is completed, the motor enters a preset intermittent stop phase. Once the cumulative number of completed strokes reaches the current target number of strokes, the control system enters a new mining and discharge cycle.

[0050] In practice, the control system precisely manages the stroke timing through hardware timer interrupts. Upon completion of an upward or downward stroke, the motor control state is immediately switched to the "intermittent stop" phase, and an independent stop timer begins accumulating the stop time T_stop. The duration of the intermittent stop is not a fixed value but is dynamically calculated by the core algorithm. The calculation is based on: the current target stroke count N (higher stroke counts result in shorter intervals), the target velocity V (higher velocity may require longer intervals), and the downhole fluid supply capacity estimated in real-time based on recent fluid production and fluid level recovery speed. For example, if the fluid supply capacity is poor, the interval time is automatically extended to allow the formation more time to collect fluid and prevent "dry pumping." During the stop phase, the control system shuts down all IGBT drive signals, placing the motor in a free state, but maintains data acquisition and fault monitoring logic from all sensors. Simultaneously, a dedicated stroke counter accumulates the effective strokes completed upon receiving the commutation signal. When the accumulated value reaches the current cycle target stroke count N, it marks the end of a complete production and drainage cycle (e.g., lasting 10 minutes). At this point, the system first executes the cycle switching routine: summarizing the operating data of the previous cycle, such as average operating current, actual liquid level drop, and total power consumption, and calculating the cycle pump efficiency. Based on the pump efficiency evaluation results, the system fine-tunes the target parameters for the next cycle. For example, if the pump efficiency remains low, the number of strokes N may be slightly reduced or the interval time T_stop may be extended in the next cycle to achieve incremental optimization between cycles. Subsequently, the system resets the stroke counter and stop timer, and based on the latest operating mode decision, seamlessly enters the next sampling and drainage cycle, restarting the cycle from step S102. During the intermittent stop phase, to reduce energy consumption, the control system can automatically adjust the power of auxiliary circuits (such as some indicator lights) or put the processor into a low-power monitoring mode until the next action command is triggered.

[0051] The beneficial effects of this step are: 1. Achieve supply and demand coordination and improve pump efficiency: By dynamically calculating the intermittent time, the pumping rhythm is matched with the formation fluid supply capacity, which effectively avoids the problem of low pump efficiency and "cylinder knocking" caused by insufficient fluid supply, and significantly improves system efficiency.

[0052] 2. Energy saving and consumption reduction: During the intermittent period, it enters a low power consumption mode and optimizes the operating parameters by evaluating the cycle performance, thereby reducing the unit liquid production energy consumption of the device as a whole.

[0053] Step S107: Comprehensive security monitoring and protection.

[0054] The system monitors motor current, temperature, and communication status in real time. When any monitored data is compared with the corresponding protection threshold and a fault is triggered, the control system immediately executes emergency shutdown protection and records the fault information.

[0055] In practice, the control system implements multi-dimensional parallel monitoring. The three-phase current of the motor is sampled by Hall sensors, converted by an ADC, and compared in real time with the overcurrent protection threshold (e.g., 1.5 times the rated current). The temperature of the motor windings and the downhole environment is collected by a PT1000 platinum resistance temperature sensor, converted by an ADC, and compared with the over-temperature protection threshold (e.g., 120℃). The communication status is comprehensively evaluated by monitoring the bit error rate, response timeout count, and CRC check failure count of the serial interface. To improve protection sensitivity and accuracy, the overcurrent and over-temperature protection thresholds are not fixed but dynamically managed by a background learning algorithm. This algorithm periodically (e.g., daily) fine-tunes each threshold based on the motor's recent historical operating load curve, the ambient temperature baseline, and the equipment's cumulative operating time (reflecting aging trends). For example, in the early stages of equipment operation, the overcurrent threshold may be set more conservatively; after stable operation, it can be appropriately relaxed based on the learning results to improve equipment utilization; in the later stages of operation, the threshold may be tightened again to protect aging equipment. When any monitored data exceeds its dynamic threshold (e.g., a phase current instantaneously reaches 70A), the control system immediately triggers the highest-priority non-maskable interrupt. This interrupt service routine first unconditionally blocks all IGBT PWM drive signals (outputs are all low), and simultaneously controls a safety relay to cut off the main power circuit, achieving a hardware-level emergency shutdown. At the same time, the system encodes the specific fault type (e.g., "Code 71: U-phase overcurrent"), the instantaneous current, voltage, and temperature snapshot data, and the current operating parameters, packaging them into a record with a precise timestamp, encrypting it, and saving it to a dedicated fault log sector in the EEPROM. Furthermore, the system integrates a predictive maintenance mechanism based on trend analysis. Through continuous analysis of indicators such as motor current harmonic components and temperature rise rate, it identifies potential risks before physical thresholds are exceeded (e.g., slight bearing wear leading to increased current harmonics) and reports early warning information, achieving a leap from "shutdown after a fault" to "early warning before a fault."

[0056] The beneficial effects of this step are: 1. Extremely high system reliability: Through multiple mechanisms such as "software and hardware integration, multi-dimensional monitoring, dynamic thresholds, and rapid hardware protection", the system provides the highest level of security protection for the device, minimizing equipment damage.

[0057] 2. Possesses predictive maintenance capabilities: By analyzing trends, potential faults can be identified in advance, providing a basis for planned maintenance, reducing unplanned downtime, and improving production management.

[0058] Step S108, Dual-mode control and remote collaboration.

[0059] The control system supports both local manual control and remote automatic control modes. In remote automatic control mode, the control system receives and parses remote commands to update operating parameters and automatically executes a closed-loop process from parameter acquisition to stroke control.

[0060] In practice, the control system defines and manages the operating mode through the value of a core variable (EE_RUN). In local manual mode (EE_RUN=1), the control system only responds to button operations on the touchscreen (such as the MCGS configuration screen) connected locally to the controller, and actively blocks any control commands from the remote communication port (RS-485), ensuring absolute safety and operational priority during on-site commissioning and maintenance. In remote automatic mode (such as EE_RUN=5), the control system continuously monitors the network through the serial communication interface, receiving and parsing command frames in Modbus-RTU format sent by the remote monitoring center. After CRC verification and simple password authentication, the target parameters (such as the new target stroke, target liquid level) contained in the command frame are temporarily stored in the receive buffer variable (RX_BUF). Subsequently, the control system, through a parameter synchronization mechanism, updates the valid parameters in the receive buffer to the current operating parameters (EE_*) while ensuring security (e.g., comparing the differences between the new parameters and the current parameters and confirming that they are within a reasonable range), and immediately writes them to the EEPROM for persistent storage. After parameter updates, the control system can automatically and seamlessly transition to the new control logic without restarting, continuously executing the closed-loop control process from steps S102 to S107 based on the new target parameters. During remote control, if the system detects that the local emergency stop button has been pressed, it will immediately suspend the execution of any remote command sequence, prioritize local safety commands, enter a shutdown protection state, and support recovery from the breakpoint or restart according to a preset strategy after the fault is cleared. Furthermore, the system possesses self-awareness and fault tolerance capabilities regarding link status. When remote communication is interrupted, it can automatically maintain the last set of valid control parameters from before the interruption and continue operation. After communication is restored, it automatically reports the operation log during the interruption and synchronizes the status with the monitoring center, ensuring the continuity and controllability of the production process.

[0061] The beneficial effects of this step are: 1. Flexible operation, adaptable to modern production management: It supports local emergency intervention and remote intelligent optimization, which not only ensures on-site safety, but also meets the development needs of digitalization and unmanned operation in oil fields.

[0062] 2. Safe and reliable, production continues even when the network is down: Strict command authentication, local priority principle, and fault-tolerant operation mechanism ensure the security of control and the continuity of the production process.

[0063] This application also provides a control system for a linear motor submersible reciprocating oil extraction device, which is used to execute the above-described control method. The system includes: The parameter management module is used to read preset operating parameters from non-volatile memory after the control system is powered on, and supports receiving and parsing remote commands to update operating parameters.

[0064] The data acquisition and communication module is used to cyclically acquire downhole operating condition signals at a preset frequency, and then upload the acquired signals after filtering and protocol encapsulation.

[0065] The decision control module is used to determine the target number of strokes and target operating speed for the current mining and discharge cycle based on the deviation between the real-time collected operating data and the target parameters, combined with the preset operating mode, through a control algorithm.

[0066] The motor drive and control module is used to perform closed-loop speed regulation with the target speed as the set value during the upward or downward phase of the motor, and output drive signals to control the linear motor to run according to preset logic, and to control the motor to run at the unblocking speed to generate high-speed jet during the preset phase.

[0067] The cycle management module is used to control the motor to enter the intermittent stop phase after a single stroke is completed, and to start a new mining cycle after the cumulative number of strokes reaches the target number of strokes.

[0068] The safety monitoring and protection module is used to monitor the system status in real time. When the monitored data triggers a fault, it immediately executes emergency shutdown protection and records the fault information.

[0069] The functionality of these modules corresponds to the specific descriptions of steps S101 to S108 of the above method, and will not be repeated here.

[0070] It should be noted that the terms "first," "second," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "a" or "one," and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. "A plurality" or "several" indicates at least two. Unless otherwise stated, terms such as "front," "back," "left," "right," "lower," and / or "upper" are for illustrative purposes only and are not limited to a location or spatial orientation. Terms such as "comprising" or "including" indicate that the elements or objects preceding "comprising" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0071] The singular forms “a,” “the,” and “the” used in this application specification and appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0072] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A control method for a linear motor submersible reciprocating oil extraction device, characterized in that, The control method includes the following steps: S101 After the control system is powered on, it reads the preset operating mode parameters, target stroke parameters, upward speed parameters, downward speed parameters and target liquid level depth parameters from the non-volatile memory, and completes the initialization configuration of each hardware module of the control system. S102 uses an analog-to-digital converter to cyclically collect downhole pressure signals, temperature signals, liquid level signals, and motor current signals at a preset frequency. It filters the collected multiple consecutive sampling points and uploads them after encapsulation and verification according to a preset communication protocol. S103, based on the deviation between the real-time collected operating data and the target parameters, combined with the preset operating mode, uses a PID and fuzzy control fusion algorithm to determine the target stroke, target upward speed, and target downward speed of the current sampling and discharge cycle. S104, during the upward or downward phase of the motor, uses the target speed determined by the decision as the set value and the speed calculated in real time as the feedback value for adjustment, and dynamically outputs drive signals to control the linear motor to run according to the preset commutation logic. S105, during the preset phase of the motor's downward stroke, controls the motor's mover to complete a stroke at a preset unblocking speed higher than the discharge speed, so as to generate a high-speed jet; S106, after a single upward and downward stroke is completed, the motor enters a preset intermittent stop phase; after the cumulative number of completed strokes reaches the current target number of strokes, the control system enters a new mining and discharge cycle; S107 monitors motor current, temperature and communication status in real time. When any monitored data is compared with the corresponding protection threshold and a fault is triggered, the control system immediately executes emergency stop protection and records the fault information. S108, the control system supports local manual control mode and remote automatic control mode; in remote automatic control mode, the control system receives and parses remote commands to update operating parameters, and automatically executes the closed-loop process from parameter acquisition to stroke control.

2. The control method for the linear motor submersible reciprocating oil extraction device according to claim 1, characterized in that, Step S101 includes: The control system, centered on a DSP chip, first reads pre-stored parameters such as operating mode, target stroke, uplink speed, downlink speed, and target liquid level depth from the non-volatile memory area of ​​the DSP chip's EEPROM. Subsequently, the control system initializes the analog-to-digital converter module, timer module, PWM drive module, and serial communication module sequentially. The analog-to-digital converter module is configured for multi-channel cyclic sampling mode, the timer module is set as the base clock for generating the motor commutation and control cycle, the PWM module is set to complementary output mode to drive the subsequent IGBT power bridge, and the serial communication module is initialized... The baud rate is preset to prepare for data exchange; a parameter verification mechanism is integrated during the parameter loading stage, which determines whether the various parameter values ​​read from the EEPROM are within the preset reasonable threshold range. If a parameter value exceeds the limit, the recovery program is automatically called to reset the parameter value to a safe default value and rewrite it to the EEPROM; after all hardware modules are initialized, the control system performs a self-test operation covering all key output ports and status indicator lights, and generates a status message containing the control system version, loading parameters and self-test results, which is uploaded through the serial communication module, thus completing the complete startup process from static parameter loading to dynamic function readiness.

3. The control method for the linear motor submersible reciprocating oil extraction device according to claim 2, characterized in that, Step S102 includes: The control system uses the ADC module built into the DSP chip as its core, configured in a multi-channel cyclic sampling mode. It sequentially acquires analog signals from the motor current, tubing pressure, casing pressure, and temperature sensors at a fixed sampling frequency. For each channel, the control system executes a digital filtering algorithm, continuously acquiring several raw data points within one sampling cycle. The arithmetic mean of these raw data points is then calculated and used as the valid sample value for that sampling cycle. The acquisition of the analog signals from the motor current, tubing pressure, casing pressure, and temperature sensors is completed within a preset data update cycle, and all analog signals acquired within the same data update cycle are assigned a uniform label. Timestamp; The processed data is organized into message frames conforming to the Modbus-RTU format. Before transmission, the CRC-16 checksum of the frame data is calculated and appended to the end of the message, and then transmitted through the RS-232 serial physical interface; Hardware noise isolation circuit is introduced at the ADC sampling front end, and recursive median filtering is used at the software level to suppress sudden spike interference; The validity of the analog signals of motor current, oil pipe pressure, casing pressure and temperature sensors is continuously monitored. If the analog signal is continuously out of range or disconnected, the abnormal state is marked in the data frame, and the valid data of the previous cycle or the default safety value is temporarily replaced according to the preset strategy.

4. The control method for the linear motor submersible reciprocating oil extraction device according to claim 3, characterized in that, Step S103 includes: The control system uses the real-time acquired deviation between the liquid level depth and the target liquid level depth, as well as the pressure difference between the casing pressure and the tubing pressure, as core input variables. The preset operating mode determines the priority of the control target. In local manual or remote automatic mode, the preset stroke rate and speed are directly adopted. In liquid level control mode, an adaptive decision-making process is initiated. In liquid level control mode, the core decision-making employs a two-stage algorithm that integrates PID control and fuzzy control. The first stage is a fuzzy decision-maker, which fuzzifies the two precise quantities—liquid level deviation and pressure difference—into linguistic variables including "negative large," "negative small," "zero," "positive small," and "positive large." Based on a pre-set expert experience rule base, it outputs adjustments to the target stroke rate and target speed. The first level consists of a factor; the second level is a parameter self-tuning PID controller, which uses the adjustment factor output by the previous level fuzzy decision-maker as a real-time correction quantity to dynamically fine-tune the proportional, integral, and derivative coefficients of the PID controller; the second-level algorithm, which integrates PID control and fuzzy control, outputs three sets of decision values ​​for the optimal target stroke, target upward speed, and target downward speed within the current production and drainage cycle; the second-level algorithm, which integrates PID control and fuzzy control, includes a performance evaluation module, which compares the actual liquid level change rate after one decision cycle with the expected change rate, and adaptively optimizes the weights of some rules in the fuzzy rule base with a small step size based on the comparison results, so that the control system can slowly approach the optimal control strategy for a specific oil well.

5. The control method for the linear motor submersible reciprocating oil extraction device according to claim 4, characterized in that, Step S104 includes: The control system obtains the target upward speed and target downward speed from the decision in step S103, and uses them as the set values ​​for their respective motion directions. The speed feedback value is obtained by measuring the motor commutation cycle through a high-precision timer and calculating it in real time, forming a closed-loop control speed feedback loop. The core controller uses a PID algorithm to calculate and output the duty cycle of the PWM signal used to drive the IGBT power bridge in real time by performing proportional, integral, and derivative operations on the deviation between the set value and the feedback value. Feedforward compensation is introduced into the PID algorithm, that is, the load disturbance of the current stroke is predicted based on the historical data of current and pressure of the previous stroke, and the PWM duty cycle is compensated and adjusted in advance. The PWM drive module outputs signals in a complementary manner, controlling the IGBT's on and off in an orderly manner through preset commutation logic, thereby driving the linear motor's mover to run at a constant speed. The commutation logic is strictly triggered by a hardware timer interrupt to ensure the accuracy of the commutation timing. To prevent integral term saturation and control failure during startup, shutdown, or when encountering obstacles, the PID algorithm incorporates an anti-integral saturation mechanism, automatically freezing the integral action when the output PWM duty cycle reaches the limit value. The control system integrates a state observer in the speed loop, using motor current and back EMF information to perform soft measurement of the actual speed, serving as a redundancy check and smoothing filter for encoder or timer speed measurement methods.

6. The control method for the linear motor submersible reciprocating oil extraction device according to claim 5, characterized in that, Step S105 includes: At the end of the motor's downward stroke, when the mover position enters the preset unblocking trigger range, the control system initiates the jet unblocking control sequence. The unblocking trigger is dynamically determined by the intelligent decision module, based on real-time monitoring of the production rate decline trend, downhole pressure fluctuation characteristics, and historical unblocking records. Triggering only occurs when a comprehensive assessment indicates a risk of perforation blockage. After the unblocking sequence is initiated, the control system immediately switches the motor's downward speed from the current drainage speed to the preset high-speed unblocking speed. During the high-speed downward phase, the control system uses high-precision position estimation or sensor feedback to control the mover to complete a fixed short stroke at the unblocking speed. At the end of the high-speed stroke, the control logic includes a brief pressure stabilization phase to allow the fluid kinetic energy to fully act on the blockage before transitioning to the normal shutdown or reversal process. After each unblocking action, the control system enters a monitoring period, tracking pressure and production rate changes in the subsequent drainage cycles. By comparing the operating data before and after unblocking, the system automatically evaluates the unblocking effect and uses the evaluation results to learn and optimize the trigger threshold and speed parameters for the next unblocking operation.

7. The control method for the linear motor submersible reciprocating oil extraction device according to claim 6, characterized in that, Step S106 includes: The control system precisely manages stroke timing through hardware timer interrupts. Upon completion of a single upward or downward stroke, the motor control state is immediately switched to an intermittent stop phase, and an independent stop timer begins accumulating time. The duration of the intermittent stop is dynamically calculated by the core algorithm, based on the current target number of strokes, target speed, and real-time estimated downhole fluid supply capacity. During the stop phase, the control system shuts down all IGBT drive signals, placing the motor in a free state, but maintains the acquisition of all sensor data and fault monitoring logic. Simultaneously, a dedicated stroke counter accumulates the completed effective strokes. When the stroke count reaches the target stroke count for the current cycle, it marks the end of a complete sampling and output cycle. First, the control system executes the cycle switching routine, which includes summarizing and evaluating the operating data of the previous cycle, and fine-tuning the target parameters or interval time of the next cycle based on the evaluation results, to achieve incremental optimization between cycles. Subsequently, the control system resets the stroke counter and stop timer, and decides on the latest operating mode to enter the next sampling and output cycle, restarting the cycle from step S102. During the intermittent stop phase, the control system automatically adjusts the power of the auxiliary circuit or enters a low-power monitoring mode until the next action command is triggered.

8. The control method for the linear motor submersible reciprocating oil extraction device according to claim 1 or 7, characterized in that, Step S107 includes: The control system implements multi-dimensional parallel monitoring. Motor phase current is sampled by Hall effect sensors and converted into digital values ​​by an ADC module, then compared in real-time with overcurrent protection thresholds. Motor winding and downhole ambient temperatures are collected by PT1000 sensors, also converted by an ADC, and compared with over-temperature protection thresholds. Communication status is comprehensively evaluated through serial interface bit error rate statistics, response timeout counters, and CRC check failure counts. A background learning algorithm periodically fine-tunes the overcurrent and over-temperature protection thresholds based on historical motor operating load, ambient temperature baseline, and equipment aging trends. When any monitored data exceeds its dynamic threshold, the control system... The system immediately triggers the highest priority fault interrupt. The fault interrupt first unconditionally blocks the PWM drive signals of all IGBTs and controls the relay to cut off the main power circuit, realizing a hardware-level emergency shutdown. At the same time, the control system packages the specific fault type code, the snapshot data of the fault moment, and the current operating parameters into a timestamped encrypted fault record, which is saved to a dedicated sector of non-volatile memory. The control system integrates a predictive maintenance mechanism based on trend analysis. The predictive maintenance mechanism continuously analyzes indicators including current harmonics and temperature rise rate to identify potential risks before physical thresholds are exceeded and reports early warning information in advance.

9. The control method for the linear motor submersible reciprocating oil extraction device according to claim 2, characterized in that, Step S108 includes: The control system defines and manages operating modes through the values ​​of core variables. In local manual mode, the control system only responds to button operations on the MCGS configuration screen connected locally to the controller and actively blocks any control commands from the remote communication port. In remote automatic mode, the control system continuously monitors the network through a serial communication interface, receives and parses remote command frames conforming to the Modbus-RTU format. After CRC verification and authentication, the target parameters contained in the remote command frames are temporarily stored in the receive buffer variable. Subsequently, the control system, through a parameter synchronization mechanism, compares the valid parameters in the receive buffer with the current operating parameters while ensuring security. If there is a change, the system will automatically update the receiving buffer. After secondary confirmation, the operating parameters are updated and immediately written to EEPROM for persistent storage. After the parameters are updated, the control system can automatically and seamlessly connect to the new control logic without restarting, and continue to execute the closed-loop control process from steps S102 to S107 according to the new target parameters. During remote control, if a local emergency stop signal is detected, the control system will immediately suspend the execution of the remote command sequence, prioritize the response to local safety commands, and support recovery from the breakpoint or restart according to the preset strategy after the fault is cleared. The control system can automatically maintain the last set of valid parameters before the interruption and continue to operate when remote communication is interrupted, and automatically report the operation log and synchronization status after communication is restored.

10. A control system for a linear motor submersible reciprocating oil extraction device, characterized in that, The control system includes: The parameter management module is used to read preset operating parameters from non-volatile memory after the control system is powered on, and supports receiving and parsing remote commands to update the operating parameters; The data acquisition and communication module is used to cyclically acquire downhole working condition signals at a preset frequency, and upload the acquired signals after filtering and protocol encapsulation. The decision control module is used to determine the target number of strokes and target running speed for the current mining and discharge cycle based on the deviation between the real-time collected operating data and the target parameters, combined with the preset operating mode, through the control algorithm. The motor drive and control module is used to perform closed-loop speed regulation with the target speed determined as the set value during the upward or downward phase of the motor, and output drive signals to control the linear motor to run according to preset logic, and to control the motor to run at the unblocking speed to generate high-speed jet during the preset phase. The cycle management module is used to control the motor to enter the intermittent stop phase after a single stroke is completed, and to start a new mining cycle after the cumulative number of strokes reaches the target number of strokes; The safety monitoring and protection module is used to monitor the system status in real time. When the monitored data triggers a fault, it immediately executes emergency shutdown protection and records the fault information.

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