Super capacitor bank energy storage type motor speed regulation workover rig

Abstract

The invention relates to the technical field of oil exploitation, in particular to a super capacitor bank energy storage type motor speed regulation workover rig. Comprising a motor speed regulation system which comprises an inversion unit and a variable-frequency and variable-speed motor electrically connected with the inversion unit; the input end of the three-phase active rectification unit is connected with the commercial power grid, and the output end is connected with the DC bus; the bidirectional DC-DC converter is respectively connected with the DC bus and the super capacitor module; according to the super capacitor module, the temperature rise of each super capacitor monomer under the maximum discharge current does not exceed 40 DEG C, and the cycle life is not less than 100000 times under the condition of 1C; the sampling period Ts of the controller is smaller than or equal to 10ms, and the controller is used for collecting parameters and outputting control signals according to the parameters. According to the invention, the power supply side adopts the super capacitor for power compensation and is equipped with the quick-response bidirectional power electronics and controller, so that'peak load shifting 'is realized, the operation continuity is improved, the dependence on the transformation of a well site transformer is reduced, the regenerated energy of the put-down operation is recovered, the brake wear is reduced, and the energy utilization efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of oil extraction technology, and in particular to a supercapacitor-based energy storage motor speed-regulating workover rig. Background Technology

[0002] Existing workover rigs primarily use diesel engines or variable frequency motors directly driven by the well site's mains power. The disadvantages of diesel drive include low energy efficiency, emissions, and frequent start-stop maintenance. While electric drive reduces pollution, in my country and some oilfield well sites, the small-capacity power distribution systems (common transformer capacities of 50–200 kW) often result in instantaneous peak power exceeding the mains power capacity (e.g., above 300 kW) during hoisting or heavy-duty operations. This necessitates temporary power reduction, work stoppages, or grid modifications, severely impacting economic efficiency and work effectiveness. Furthermore, the regenerative energy used during traditional tubing lowering is often consumed by brake pads, leading to energy waste and brake wear.

[0003] Existing technologies have proposed incorporating energy storage systems (batteries / supercapacitors) into hoisting / winch-type equipment to mitigate instantaneous peak loads. However, most publications only present the concept ("adding energy storage for parallel compensation") or only provide a single component (e.g., bidirectional DC-DC or simple control strategies). They lack a complete implementation plan that integrates specific power electronic topologies, active current sharing, thermal management, rapid switching / response time, and measured results into a holistic device and submits it as a workover rig. Therefore, a comprehensive workover rig solution that is engineering-feasible, has proven practical effectiveness, and includes key implementation details within its protection scope is still needed. Summary of the Invention

[0004] In order to overcome the existing technical defects, the purpose of this invention is to provide a supercapacitor-based energy storage motor speed-regulating workover rig. By using supercapacitor power compensation on the power supply side and equipping it with fast-response bidirectional power electronics and intelligent controller, it can achieve peak shaving and valley filling, improve the continuity of operation and reduce the dependence on well site transformer modification. At the same time, it can recover the regenerative energy of the workover operation, reduce brake wear and improve energy utilization efficiency.

[0005] This invention discloses a supercapacitor-based energy storage motor speed-regulating well workover rig, comprising:

[0006] The motor speed control system includes an inverter unit and a variable frequency speed control motor electrically connected to the inverter unit;

[0007] The three-phase active rectifier unit (AFE) has its input end connected to the mains power grid and its output end connected to the DC bus, and has harmonic suppression and regenerative energy feedback functions.

[0008] The bidirectional DC-DC converter adopts a non-isolated buck-boost topology and is equipped with an active current sharing circuit. One end of it is connected to the DC bus, and the other end is connected to the supercapacitor module.

[0009] The supercapacitor module is composed of multiple supercapacitor cells connected in series / parallel. Each parallel branch is equipped with an active current sharing circuit, and the current deviation is controlled within 5%. The outer shell of the supercapacitor module is equipped with a liquid cooling channel and distributed temperature sensors to ensure that the temperature rise of each supercapacitor cell does not exceed 40°C under the maximum discharge current, and the cycle life is not less than 100,000 times under 1C conditions.

[0010] The controller, with a sampling period Ts ≤ 10ms, is used to collect data on the load weight W and the lifting or lowering speed. The supercapacitor charge S and the mains bus voltage Vgrid are used, and the load weight W and lifting or lowering speed are also considered. The supercapacitor charge S and the mains bus voltage Vgrid output control signals;

[0011] When the mains voltage drops by more than 15% and the supercapacitor charge S is greater than or equal to the preset threshold Smin, the controller will drive the bidirectional DC-DC converter into discharge mode within 50ms to keep the DC bus voltage deviation within ±10% of the rated value.

[0012] Preferably, the controller includes a fuzzy controller, which includes:

[0013] Membership function: W∈{light, medium, heavy}, ∈{slow, medium, fast}, S∈{low, medium, high}, Vgrid∈{low, normal, high};

[0014] Rule matrix: When Vgrid is low and s is high, output a discharge command; when Vgrid is high and S is low, output a charge command; when Vgrid is normal, maintain standby.

[0015] Priority determination strategy: Safety control > Ensuring operational continuity > Optimizing energy efficiency.

[0016] Preferably, the controller has an adaptive function, which can adjust the boundary values ​​of the membership function based on historical operating data;

[0017] The controller has a fault-tolerant mode. When the mains voltage drops by more than 30% and the supercapacitor charge S ≤ the preset threshold Smin, the controller triggers the emergency current limiting mode and disconnects the load.

[0018] Preferably, the equivalent series resistance of a single supercapacitor cell satisfies: Where U is the rated voltage of a single unit. is the maximum discharge current, and n is the number of cells connected in series.

[0019] Preferably, the switching frequency range of the bidirectional DC-DC converter is 10-20kHz, and the current sharing error is ≤5%.

[0020] Preferably, the variable frequency speed control motor is a permanent magnet synchronous motor with a speed range of 0-1500 rpm.

[0021] Preferably, it also includes a winch hydraulic disc brake device, the braking torque of which satisfies: Where F is the braking force and r is the braking radius. For transmission efficiency.

[0022] Preferably, the oil pump flow rate of the winch hydraulic disc brake device meets the following requirements: Where V is the effective volume of the hydraulic cylinder, n is the number of hydraulic cylinders, and t is the braking time.

[0023] Preferably, it also includes a derrick system, wherein the allowable stress of the derrick system's overhead crane pulley block satisfies: ,in, A represents the force acting on the surface, and A represents the cross-sectional area.

[0024] Preferably, the derrick system includes a derrick body, which is a foldable structure, and its folded length is less than the length of the transport vehicle.

[0025] After adopting the above technical solution, the beneficial effects of the present invention compared with the prior art are as follows:

[0026] 1. This invention employs a combination of a three-phase active rectifier unit (AFE), a bidirectional non-isolated buck-boost DC-DC topology (parallel active current sharing circuit), and an inverter unit on the DC bus side to achieve a dual power supply mode of "grid main supply + supercapacitor compensation" in parallel with the mains power.

[0027] 2. The supercapacitor module adopts a modular design with series and parallel connection, active current sharing, distributed temperature sensing, and liquid cooling to meet the requirements of high-rate discharge, high-current sharing, and lifespan.

[0028] 3. The controller adopts a hybrid strategy of **fuzzy control + priority determination (safety first)**, with a short sampling period (Ts ≤ 10 ms). In the event of a mains power drop (e.g., exceeding 15%), it can initiate compensation within ≤50 ms, maintain the DC bus deviation ≤±10%, and ensure continuous motor operation. The controller is implemented on an FPGA / MCU platform and supports adaptive membership boundaries and online parameter adjustment based on historical data.

[0029] 4. Mechanically, provide winch hydraulic disc brake and redundant braking schemes, folding derrick structure, and provide mechanical and hydraulic design formulas to ensure safety and convenient transportation. Attached Figure Description

[0030] Figure 1 This is a schematic block diagram of a supercapacitor-based energy storage motor speed-regulating well workover machine according to the present invention.

[0031] Figure 2 This is a schematic diagram of the bidirectional DC-DC converter topology in a supercapacitor-based energy storage motor speed-regulating well workover rig of the present invention.

[0032] Figure 3 This is a schematic diagram of the topology of the inverter unit driving the motor in the controller of a supercapacitor-based energy storage motor speed-regulating well workover rig of the present invention.

[0033] Figure 4 This is a schematic diagram of the supercapacitor module in a supercapacitor-based energy storage motor speed-regulating well workover machine according to the present invention. Detailed Implementation

[0034] The advantages of the present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments.

[0035] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0036] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the 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 and all possible combinations of one or more of the associated listed items.

[0037] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0038] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0039] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0040] In the following description, suffixes such as "module," "part," or "unit" used to denote elements are used only for the convenience of the description of the invention and have no specific meaning in themselves. Therefore, "module" and "part" can be used interchangeably.

[0041] See Figures 1 to 4 As shown in the figure, this embodiment will provide a detailed description of a supercapacitor-based energy storage motor speed-regulating well workover rig.

[0042] This supercapacitor-based energy storage motor speed-regulating workover rig mainly includes the following:

[0043] Mains input and three-phase active rectifier unit (AFE);

[0044] DC bus (bus capacitor, bus voltage monitoring, pre-charge resistor, circuit breaker / fuse);

[0045] Inverter unit (IGBT / SiC MOSFET full-bridge or three-phase bridge drive, output connected to permanent magnet synchronous motor);

[0046] Bidirectional DC-DC converter (non-isolated buck-boost, with active current sharing plate);

[0047] Supercapacitor modules (modular series / parallel connection, active current sharing, liquid cooling, temperature sensing);

[0048] Controller (FPGA+MCU combination, or high-performance MCU+DSP, sampling period TS≤10ms).

[0049] Protection and monitoring (overvoltage, undervoltage, overcurrent, temperature, insulation monitoring, short circuit protection, hardware emergency stop);

[0050] Mechanical components (winch unit, gearbox, wire rope, derrick, hydraulic disc brake);

[0051] The units are connected via a power or information bus. The controller centrally samples signals such as voltage, current, temperature, and heavy load, and then issues charging / discharging / inverter reference / braking commands.

[0052] Active rectifier unit (AFE)

[0053] Function: Rectifies mains power (three-phase) into DC and charges the DC bus. It can also regenerate and connect to the grid during inverter or supercapacitor feedback (if the well site allows) and suppress harmonics.

[0054] Key implementation points: A three-phase bridge (IGBT / SiC MOSFET) controlled by PWM is used, with neutral point balancing, an input LC filter network, and a grid connection control loop. A pre-charging resistor is used during rectification to limit inrush current; circuit breaker / fuse pre-phase sequence detection is provided at the rectifier terminals.

[0055] Parameters (example): Rated bus voltage 400Vdc; rectifier output filter capacitor 2000-5000 Switching frequency 5-10kHz (depending on the device).

[0056] Inverter unit and variable frequency motor

[0057] Inverter Unit: A three-phase full-bridge inverter that uses PWM / vector control (Field Oriented Control, FOC) to drive a permanent magnet synchronous motor (PMSM). The inverter features overcurrent protection, undervoltage / overvoltage detection, and regenerative energy current limiting.

[0058] Motor: Permanent magnet synchronous motor with a rated speed limit of 1500 rpm (example), equipped with encoder feedback to achieve closed-loop speed / position control.

[0059] Key control points: The vector control algorithm implements the current loop (inner loop) and speed loop (outer loop), and works with the energy manager to adjust the reference torque / speed.

[0060] Bidirectional DC-DC converter (power electronic implementation details)

[0061] Topology: It adopts a non-isolated buck-boost bidirectional architecture (also known as bidirectional single-ended / half-bridge or X-type topology), preferably using a structure composed of two half-bridges (or full bridges) connected by a high-frequency link, which can perform boost or buck conversion between the low-side (supercapacitor module side) and the bus side.

[0062] Active current sharing: When multiple modules are connected in parallel, an active current sharing circuit (such as a low-power DC-DC step-down / step-up converter or current sharing switch) is set at the output of each module, and the main controller realizes the current balance of the parallel branches through communication / sampling, with a target parallel current deviation ≤5%.

[0063] Switching frequency: 10-20kHz (example) to balance loss and filter size.

[0064] Protection features include current limiting, soft start, over-temperature shutdown, short circuit detection, and hardware circuit breakers. When a single module failure is detected, the module is automatically reclassified and the remaining modules are rebalanced.

[0065] Time response: The time from receiving the compensation trigger signal to establishing the output compensation current should not exceed 50ms. Therefore, the communication between the main controller and the power unit, the switch drive, and the loop bandwidth need to be designed to meet this response time.

[0066] DC-DC master / slave control strategy (example)

[0067] Normal operation (sufficient mains power): The DC-DC converter operates in buck / charging mode, channeling excess energy from the bus or motor feedback energy into the supercapacitor as a controlled current; the charging current is limited by I_charge_max (to avoid impacting the power grid). Each parallel branch is equipped with an active current sharing submodule and a temperature sensor.

[0068] Peak compensation (insufficient mains power or mains power drop): The controller issues a fast discharge command, the DC-DC switches to boost discharge mode, and injects compensation power P_comp into the bus (not exceeding the supercapacitor's allowable discharge capacity).

[0069] The switching logic includes soft switching / closed-loop current limiting to avoid voltage jitter.

[0070] Supercapacitor Module Design

[0071] Modular architecture: A module consists of m series × p parallel supercapacitor cells (m and p are determined by the required voltage and capacitance). Each parallel branch is equipped with an active current sharing submodule and a temperature sensing point.

[0072] Active current sharing is achieved by using a high-frequency switching current sharer based on DC-DC converter, combined with a digital control algorithm to ensure that the current deviation of parallel branches is ≤5%.

[0073] Thermal Management: The module housing is equipped with a liquid cooling channel (cooling plate / cold plate), which, together with the cooling pump, coolant, and radiator, forms a liquid cooling system; temperature sensors are distributed at key locations in each parallel branch, and the controller adjusts the pump speed / fan speed according to the temperature curve. Target: Under maximum discharge current, the temperature rise of a single unit is greater than or equal to ≤40℃ (equivalent to ambient temperature).

[0074] ESR / Internal Resistance: Each cell should satisfy the equivalent series connection requirement. U is the rated voltage of a single unit. The maximum discharge current is n, and the number of cells connected in series is n, to ensure acceptable heat dissipation and lifespan.

[0075] Lifetime target: Cycle life ≥ 100,000 cycles under 1C cycling conditions (example).

[0076] Mechanical and enclosure: The modular enclosure has a protection rating of at least IP54 (for outdoor operation) and features a vibration-resistant design and a modular plug-and-play structure for easy replacement.

[0077] The controller implementation consists of two layers: a real-time hardware layer (FPGA / high-speed unit) responsible for rapid sampling and protection linkage, and an algorithm layer (DSP / MCU) responsible for fuzzy inference, strategy determination, and historical data management. The controller structure includes voltage / current sampling, temperature sampling, force / weight sensors (weighing sensors), encoders, circuit breaker status, and communication interfaces (CAN / Ethernet), etc.

[0078] Sampling and Time Requirements

[0079] The sampling period for critical quantities is TS≤10ms; protection-level sampling (overcurrent / short circuit detection) is even faster (e.g., 100ms). (Level hardware comparator).

[0080] The master controller response time (from drop detection to output compensation command) is ≤ ms (including communication, command issuance, and DC-DC switching setup current). This performance is achieved through a hardware architecture (FPGA fast interrupt / hardware trigger).

[0081] Fuzzy Controller Materialization (Membership Functions and Rule Examples)

[0082] In this embodiment, the strength of the specific membership function will be given (the values ​​are for example only, and should be adjusted according to the rated parameters in practice).

[0083] Let the maximum lifting weight of a certain piece of workover rig be... (e.g., 5000kg), definition:

[0084] Load W (kg):

[0085] Light: Trigonometric functions ;

[0086] In the middle: tri (0.15· 0.5 0.85 );

[0087] Weight: tri (0.7· , , ).

[0088] speed (m / s or rpm):

[0089] Slow: tri(0,0,0.3· );

[0090] In the middle: tri (0.15· 0.5 0.85 );

[0091] Fast: tri (0.7· , · , · ).

[0092] Battery capacity S (expressed as module SOC, 0-100%):

[0093] Low: tri (0,0,30);

[0094] Chinese: tri(20,50,80);

[0095] High: tri (70, 100, 100).

[0096] Mains voltage Vgrid (based on 100% of rated voltage):

[0097] Low: tri (0,0,85%)

[0098] Normal: tri (85%, 100%, 105%)

[0099] High: tri (103%, 120%, 120%).

[0100] Fuzzy rules (example of rule matrix):

[0101] If W = heavy and =Fast and S=Low and Vgrid=Low Then the discharge current command = The inverter output power is increased to P_ref_high (prioritizing operation continuity).

[0102] If W = light and =Slow and S=High and Vgrid=High Then the charging current command = (Slow charging), the inverter reduces power reference P_ref_low (energy saving).

[0103] If Vgrid is low but S is high The supercapacitor will discharge first to maintain bus stability, while reducing the inverter load priority.

[0104] If Vgrid is low and S is low Trigger emergency flow control / shutdown (safety mode).

[0105] Deblurring method: Centroid method is used for deblurring to obtain specific current / power commands.

[0106] The controller pseudocode is as follows (example): loop every Ts ms: read W, v, S, Vgrid, temps... fuzzified = fuzzify(W, v, S, Vgrid) rule_outputs = infer(fuzzified, rule_table) defuzzified = defuzzify(rule_outputs) command = priority_resolve(defuzzified, safety_rules) send_command_to_DC_DC(command.I_cmd) send_command_to_inverter(command.P_ref) log_samples(...) if Vgrid < V_crit_low and S < Smin: trigger_emergency_mode() open_hardware_contactor()

[0107] priority_resolve combines fuzzy output with security priorities and rate limiting strategies to ensure that safety actions that cannot be violated (such as cutting off unnecessary loads, triggering alarms, and activating mechanical brakes).

[0108] Adaptive and Historical Learning

[0109] The controller saves historical curves (bus voltage and compensation response) and uses a statistical / moving average mechanism to adjust the fuzzy membership boundary (e.g., shifting the heavy load judgment boundary to a lower value by 5% in 10 consecutive heavy load events) to adapt to the power supply characteristics of different well sites. It should be noted that the adaptive process needs to be constrained to prevent oscillations.

[0110] Protection strategies and fault tolerance

[0111] Overcurrent / overvoltage protection: hardware fast circuit breaker + software current limiting; when an over-range current is detected, it quickly enters current limiting or interrupt mode (hardware interrupt takes precedence).

[0112] Thermal runaway protection: Individual cell temperature exceeds When the temperature exceeds a preset value (e.g., 70℃) or the temperature difference exceeds the preset value, the power consumption / isolation module will be reduced and an alarm will be triggered.

[0113] Single module fault isolation: Automatically disconnects the parallel branch and recalculates the available capacity after detecting an abnormality in the parallel branch.

[0114] Mechanical emergency stop: In the event of an electrical fault, the controller triggers the hydraulic disc brake and coordinates with the mechanical brake to ensure a safe stop.

[0115] EMS and field operation interface: provides real-time status, historical curves, fault logs, and remote diagnostic interface.

[0116] Mechanical and hydraulic components

[0117] Winch unit: The gearbox adopts a multi-stage planetary gear with a transmission ratio of 1:50; the winch drum is selected based on the maximum lifting load, the wire rope diameter is 19.5 mm, and the breaking tensile strength is 200 kN.

[0118] Hydraulic disc brake: Braking torque is provided at both ends to meet the requirements. Where F is the braking force and r is the braking radius. To improve transmission efficiency, it is equipped with an oil pump-oil tank-oil pipe system, and the oil pump output flow rate meets the requirements. Where V is the effective volume of the hydraulic cylinder, n is the number of hydraulic cylinders, and t is the braking time. Redundant pumps or parallel pumps are used in the hydraulic circuit to ensure reliability.

[0119] Derrick: It adopts a folding multi-segment design, and the locking redundancy of the hinge and locking mechanism ensures the safety of transportation and use. The folding length meets the truck body length specifications.

[0120] Electromagnetic compatibility and grounding

[0121] Power electronic systems should be equipped with EMI filters, grounding loop design and enclosure shielding to meet on-site EMC requirements and reduce interference to other equipment in the well site.

[0122] For ease of understanding, this embodiment provides examples of Embodiment 1 (medium-power workover rig) and Embodiment 2 (high-power workover rig) to illustrate the specific implementation of the present invention. It should be noted that the numerical values ​​given in this embodiment are merely illustrative parameters.

[0123] Example 1 (Medium-power well workover rig)

[0124] Rated power (motor): 150kW;

[0125] Well site transformer capacity: 100kW (limited on-site);

[0126] Peak demand: 200kW, peak duration t=30s P = 200 - 100 = 100kW. Assume the operating voltage U = 400V.

[0127] The total capacitance of a supercapacitor is calculated using the formula C = 2P·t / =2·100000·30 / ( =37.5F (example).

[0128] Supercapacitor cell selection: 1F cell, 30 cells in parallel / series combination to achieve the required voltage / capacity (in conjunction with a current sharer).

[0129] The target for flow equalization error is ≤5%; liquid cooling of the module ensures that the temperature rise of each unit is ≤35℃.

[0130] Test expectation: Under the condition of a 15% instantaneous drop in mains power, the system will compensate for the 100kW peak within <50ms with a supercapacitor, control the bus voltage deviation to ≤±8%, and ensure stable motor operation without shutdown.

[0131] Example 2 (High-power well workover rig)

[0132] Rated power: 300kW; mains capacity: 200kW; peak demand: 420kW, P=220kW, t=20s, U=600V .

[0133] Each unit uses industrial capacitors such as 2.7F / 2.7V, and current sharing is achieved through series and parallel adjustment and the addition of an active current sharing module.

[0134] The test is expected to recover and discharge energy, with the supercapacitor receiving charging up to the upper limit of the peak feedback power (e.g., 150kW), and the charging current limited to avoid grid impact (e.g., not exceeding +10% of the rated grid capacity).

[0135] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A supercapacitor-based energy storage motor speed-regulating well workover rig, characterized in that, include: A motor speed control system includes an inverter unit and a variable frequency speed control motor electrically connected to the inverter unit; The three-phase active rectifier unit (AFE) has its input end connected to the mains power grid and its output end connected to the DC bus, and has harmonic suppression and regenerative energy feedback functions. The bidirectional DC-DC converter adopts a non-isolated buck-boost topology and is equipped with an active current sharing circuit. One end of the converter is connected to the DC bus, and the other end is connected to the supercapacitor module. The supercapacitor module is composed of multiple supercapacitor cells connected in series / parallel. Each parallel branch is equipped with an active current sharing circuit, and the current deviation is controlled within 5%. The outer shell of the supercapacitor module is equipped with a liquid cooling channel and distributed temperature sensors to ensure that the temperature rise of each supercapacitor cell does not exceed 40°C under the maximum discharge current, and the cycle life is not less than 100,000 times under 1C conditions. The controller, with a sampling period Ts ≤ 10ms, is used to collect data on the load weight W and the lifting or lowering speed. The supercapacitor charge S and the mains bus voltage Vgrid, and based on the load weight W and the lifting or lowering speed... The supercapacitor charge S and the mains bus voltage Vgrid output control signals; When the mains voltage drops by more than 15% and the supercapacitor charge S is greater than or equal to a preset threshold Smin, the controller drives the bidirectional DC-DC converter into discharge mode within 50ms to keep the DC bus voltage deviation within ±10% of the rated value.

2. The supercapacitor bank energy storage type motor speed-regulating well workover rig according to claim 1, characterized in that, The controller includes a fuzzy controller, which includes: Membership function: W∈{light, medium, heavy}, ∈{slow, medium, fast}, S∈{low, medium, high}, Vgrid∈{low, normal, high}; Rule matrix: When Vgrid is low and s is high, output a discharge command; when Vgrid is high and S is low, output a charge command; when Vgrid is normal, maintain standby. Priority determination strategy: Safety control > Ensuring operational continuity > Optimizing energy efficiency.

3. The supercapacitor bank energy storage type motor speed-regulating well workover rig according to claim 2, characterized in that, The controller has an adaptive function, which can adjust the boundary values ​​of the membership function based on historical operating data; The controller has a fault-tolerant mode. When the mains voltage drops by more than 30% and the supercapacitor charge S ≤ a preset threshold Smin, the controller triggers an emergency current limiting mode and disconnects the load.

4. The supercapacitor bank energy storage type motor speed-regulating well workover rig according to claim 1, characterized in that, The equivalent series resistance of the supercapacitor cell satisfies: Where U is the rated voltage of a single unit. is the maximum discharge current, and n is the number of cells connected in series.

5. The supercapacitor bank energy storage type motor speed-regulating well workover rig according to claim 1, characterized in that, The switching frequency range of the bidirectional DC-DC converter is 10-20kHz, and the current sharing error is ≤5%.

6. The supercapacitor bank energy storage type motor speed-regulating well workover rig according to claim 1, characterized in that, The variable frequency speed control motor is a permanent magnet synchronous motor with a speed range of 0-1500 rpm.

7. The supercapacitor bank energy storage type motor speed-regulating well workover rig according to claim 1, characterized in that, It also includes a winch hydraulic disc brake device, wherein the braking torque of the winch hydraulic disc brake device satisfies: Where F is the braking force and r is the braking radius. For transmission efficiency.

8. The supercapacitor bank energy storage type motor speed-regulating well workover rig according to claim 7, characterized in that, The oil pump flow rate of the winch hydraulic disc brake device meets the following requirements: Where V is the effective volume of the hydraulic cylinder, n is the number of hydraulic cylinders, and t is the braking time.

9. The supercapacitor bank energy storage type motor speed-regulating well workover rig according to claim 1, characterized in that, It also includes a derrick system, wherein the allowable stress of the derrick system's overhead crane pulley block satisfies: ,in, A represents the force acting on the surface, and A represents the cross-sectional area.

10. The supercapacitor bank energy storage type motor speed-regulating well workover rig according to claim 8, characterized in that, The derrick system includes a derrick body, which is a foldable structure, and its length after folding is less than the length of the transport vehicle.

Images