Automatic cable recovery control system for maintenance of thermal power plant

Abstract

The invention discloses an automatic cable recovery control system for thermal power plant maintenance, and relates to the technical field of thermal power plant cable maintenance. The power plant maintenance operation efficiency is greatly improved, the cable can be automatically retracted and recycled, the whole-process operation can be completed by one person, the labor cost is saved, and the equipment is flexible to move and adapts to multiple operation scenes; through tension self-adaptive winding and accurate length measurement locking, cable damage is avoided, the damage rate is reduced, the service life is prolonged, the cable winding device is compatible with cables of multiple specifications, and the universality of equipment is improved; meanwhile, multiple safety protection structures are integrated, the safety risk of field operation is greatly reduced, control is accurate, operation is easy and convenient, the state is visual, and high efficiency, safety and convenience of overhaul operation are guaranteed in an all-around mode.

Description

Technical Field

[0001] This invention relates to the field of cable maintenance technology in thermal power plants, and more specifically to an automatic cable recycling control system for thermal power plant maintenance. Background Technology

[0002] Temporary power supplies are frequently used at power plant maintenance sites. Existing power supply equipment is mostly traditional power panels. After the cables are pulled out, they need to be manually stirred by the reel, which has significant drawbacks: when working alone, maintenance operations need to be suspended to retrieve the cables, resulting in low efficiency.

[0003] When multiple people are working together, additional personnel need to be assigned to stir the reel, which wastes labor costs; uneven stirring force by hand can cause the cable to become loose, tangled, or even wear off the insulation layer.

[0004] The cable pull-out length cannot be precisely controlled; if it is too long, it can easily drag and entangle equipment, while if it is too short, it affects the operating range. During the retrieval process, the cable lacks guiding constraints, making it prone to scraping against live equipment in the power plant, posing a safety hazard. Among the existing related technologies, ordinary automatic cable reels are mostly designed for small-diameter civilian cables, lacking the power output suitable for large-section cables in power plants. They also fail to address core needs such as tension control and safety protection at maintenance sites, and lack clear PLC control algorithm support, making it impossible to achieve precise tension adjustment and length locking, and thus unsuitable for the complex operating environment of power plants. Summary of the Invention

[0005] The purpose of this invention is to solve the problems of traditional power supply equipment cable winding and unwinding in power plant maintenance, which rely on manual labor, are prone to tangling and damage, and have inaccurate length and tension control. Furthermore, civilian automatic cable reels lack power, adaptability, safety protection, and algorithm support, and cannot meet the needs of complex power plant maintenance operations.

[0006] To achieve the above objectives, the present invention specifically adopts the following technical solution:

[0007] An automatic cable retraction control system for maintenance in thermal power plants includes a main frame and power supply module, an automatic telescopic retraction module, a guiding and protection module, an operation control module, and a PLC controller. The PLC controller is electrically connected to the main frame and power supply module, the automatic telescopic retraction module, the guiding and protection module, and the operation control module to realize the linkage control of each module.

[0008] The main frame and power supply module provide the installation foundation, power supply and mobility functions for the device. Its outer shell is an insulated protective structure with built-in power supply components, a movable and fixed structure at the bottom, and adjustable handrails on both sides.

[0009] The automatic telescopic retraction module is the core execution module of the device, including a power mechanism, a clutch control component, a tension monitoring component, and a length measuring component, which realizes the cable's resistance-free pull-out, power-driven retraction, adaptive tension adjustment, and accurate length measurement.

[0010] The guiding and protection module includes a guiding component and a safety protection component, which guides and constrains the cable winding and unwinding, and provides multiple safety protections such as protection against accidental contact, overload jamming, and entanglement.

[0011] The operation control module is equipped with a human-machine interface to realize the parameter setting, mode switching, status display and command input of the equipment. Its output terminal is electrically connected to the PLC controller to receive operation commands and transmit them to the PLC controller.

[0012] The PLC controller serves as the control core, receiving data collected by the tension monitoring component and the length measuring component, as well as instruction signals from the operation control module. After processing, it outputs control instructions to each execution module and simultaneously feeds back equipment status data to the operation control module.

[0013] Furthermore, the main frame and the power supply module have built-in circuit breakers and leakage protectors. The input end is equipped with an industrial-grade protective plug, and the output end is equipped with multiple power sockets with anti-misinsertion and dustproof covers. The status signals of the circuit breaker and leakage protector are transmitted to the PLC controller. The PLC controller only allows the automatic telescopic retraction module to start when both are closed. The movable fixed structure is a universal wheel with braking function.

[0014] Furthermore, the power mechanism of the automatic telescopic retraction module includes a servo motor and a reducer. The servo motor is connected to the reducer, and the reducer is connected to the reel spindle. The reel has a replaceable structure and a cable slot on its inner wall. The servo motor supports dual-mode switching of position mode and speed mode. The speed mode is used when retracting, and the position mode is used when pulling out to the limit. The PLC controller outputs speed adjustment commands to the servo motor to realize dynamic control of the winding speed.

[0015] Furthermore, the clutch control component of the automatic telescopic retraction module is connected to the reel spindle and electrically connected to the PLC controller. When the cable is pulled out, the PLC controller controls the clutch control component to de-energize and disengage, causing the power mechanism to disconnect from the reel spindle, allowing the cable to be pulled out autonomously without resistance. When the cable is retracted, the PLC controller controls the clutch control component to energize and engage, causing the power mechanism to drive the reel spindle to rotate through the reducer, thus realizing the power recovery of the cable.

[0016] Furthermore, the tension monitoring component of the automatic telescopic retraction module includes symmetrically arranged tension sensors. These tension sensors are communicatively connected to a PLC controller, transmitting real-time cable tension data to the PLC controller at a preset frequency. The PLC controller has a built-in tension adaptive algorithm that calculates the target winding speed of the servo motor using a formula, achieving closed-loop control of tension and winding speed. The formula is:

[0017] ;

[0018] in, The target winding speed of the servo motor, This is the reference speed for the motor. This is the speed adjustment coefficient. The cable tension value is collected in real time by the pressure sensor. This is the baseline value for the upper limit of cable safety tension.

[0019] Furthermore, the PLC controller receives tension data every 0.1 seconds and substitutes it into the formula for calculation, while simultaneously setting the tension threshold control logic as follows:

[0020] when At that time, the PLC controller will Down to And trigger an alarm;

[0021] when At that time, the PLC controller will Rise to ;

[0022] when At that time, the PLC controller maintains ;

[0023] and Pre-set according to cable specifications; the larger the cable diameter, the better. The larger the value.

[0024] Furthermore, the length measuring component of the automatic telescopic retraction module includes an encoder coaxially connected to the reel spindle. The encoder is connected to a high-speed counter interface of the PLC controller. The PLC controller calculates the actual length of the cable pulled out by the cumulative pulse count of the encoder. The length calculation formula is as follows:

[0025] ;

[0026] in, This refers to the actual length of the cable pulled out. The number of cumulative pulses for the encoder. The effective diameter of the reel. For encoder resolution, This represents the gear ratio of the reducer.

[0027] Furthermore, the operation control module supports preset cable pull-out length. , The data is stored in the PLC controller's internal registers. During the cable pulling process, the PLC controller will send the data in real time. and contrast;

[0028] when At this time, the PLC controller outputs a deceleration signal to reduce the speed of the servo motor;

[0029] when = At the same time, the PLC controller simultaneously controls the clutch control component to fully engage and the servo motor to stop, achieving precise locking of the cable length;

[0030] To unlock, you can re-enter the information via the operation control module. Or press the unlock button.

[0031] Furthermore, the guiding component of the guiding and protection module includes a rotatable guide bracket and a guide wheel assembly mounted on the bracket. The width of the guide wheel groove is adjustable to accommodate cables of different specifications.

[0032] The safety protection components include an anti-accidental contact structure, an overload jamming protection structure, and an anti-tangling baffle, achieving multiple safety protections during cable winding and unwinding.

[0033] Furthermore, the human-machine interface of the operation control module includes a display screen, function buttons and status indicator lights, enabling device parameter settings, working mode switching and visual display of operating status. The PLC controller synchronizes sensor-collected data and device status data to the display screen in real time and supports data uploading to an external management system.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] 1. This invention enables automatic retraction and retrieval of cables without manual disturbance, allowing a single person to complete the entire process, increasing work efficiency by more than 60%. No additional personnel are required to handle cable retraction and retrieval, significantly reducing labor costs for power plant maintenance. Furthermore, the equipment is flexible in movement and adaptable to confined spaces and multiple work locations, further improving on-site work efficiency.

[0036] 2. This invention avoids problems such as cable loosening, knotting, pulling and wear, and redundant dragging by using tension adaptive winding with a clear algorithm and precise length measurement and locking. The cable damage rate is reduced by 90%, and the service life is extended by more than 3 times. At the same time, it is compatible with power plant cables of various specifications from Φ10-30mm, improving the versatility of the equipment.

[0037] 3. This invention integrates multiple safety protection structures such as guiding constraints, anti-accidental contact, and overload jamming protection, combined with the linkage logic of PLC controller safety protection priority, which greatly reduces the safety risks such as cable scratching and leakage between cables and live equipment in power plants; the software control part is fully disclosed, with clear calculation formulas and logic flow, realizing precise control of tension and length, simple operation and status visualization, ensuring the safety of on-site maintenance operations. Detailed Implementation

[0038] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] Example 1:

[0040] An automatic cable retraction control system for maintenance in thermal power plants includes a main frame and power supply module, an automatic telescopic retraction module, a guiding and protection module, an operation control module, and a PLC controller. The PLC controller is electrically connected to the main frame and power supply module, the automatic telescopic retraction module, the guiding and protection module, and the operation control module to realize the linkage control of each module.

[0041] Specifically, the main frame and power supply module provide the installation foundation, stable power supply and flexible mobility for the entire device, making it suitable for the harsh environment of power plant sites with dust and slight water splashes. Specifically, it includes the shell, power supply components and mobile fixed structure. The shell is made of high-strength ABS insulating material in one piece with a thickness of ≥8mm, flame retardant rating of UL94V-0, protection rating of IP54, and the corners of the shell are rounded to avoid bumping and scratching the operators or equipment during operation.

[0042] In this embodiment, the power supply component incorporates a CM1-63 series circuit breaker and a DZ47LE-32 series residual current device (RCD) to provide overload and leakage protection. The input end is equipped with an IP67-rated industrial-grade three-phase four-pole plug to ensure a sealed power connection. The output end features three multi-functional five-hole sockets and two industrial two-hole sockets, all equipped with anti-misinsertion dust covers to meet the temporary power supply needs of multiple maintenance devices in the power plant simultaneously. The on / off status signals of the circuit breaker and RCD are transmitted to the PLC controller in real time, forming a power supply priority linkage logic. Only when both are closed and the power supply status is normal will the PLC controller allow the automatic retractable module to start, preventing misoperation in the absence of power.

[0043] In this embodiment, the mobile fixed structure includes four silent omnidirectional casters with a load-bearing capacity of ≥200kg installed at the bottom of the frame. The casters are equipped with a braking function, and the brake pads have a contact degree with the wheel rim of ≥90% when braking. After braking, the equipment displacement is ≤2mm, ensuring the stability of the equipment at the work point. Foldable push-pull handrails are set on both sides of the frame. The height of the handrails can be adjusted within the range of 90-110cm to meet the movement needs of operators of different heights and facilitate the flexible transfer of the equipment between multiple work points in the power plant.

[0044] Specifically, the automatic telescopic retraction module includes a power mechanism, a clutch control component, a tension monitoring component, and a length measuring component. It is the key to realizing automatic telescopic retraction of cables and precise control of tension and length. Each component works in conjunction with the PLC controller to achieve collaborative operation.

[0045] In this embodiment, the power mechanism provides a stable driving force for cable recycling. It is compatible with various specifications of power plant-specification cables with diameters of Φ10-30mm and cross-sectional areas of 4-25mm². The power mechanism uses a 60 series servo motor with adjustable power from 500W to 1.5kW. It is equipped with a 1:20 planetary gear reducer, and the output torque is continuously adjustable from 0 to 50N・m with a torque adjustment accuracy of ±0.1N・m. The power output can be flexibly adjusted according to the cable specifications to avoid damage caused by insufficient power for recycling large-section cables or excessive power for recycling small-specification cables.

[0046] The motor supports dual-mode switching: position mode and speed mode. During cable retraction, speed mode is used, and the speed is dynamically adjusted in conjunction with the tension algorithm. When the cable pull-out length reaches the preset value, position mode is used to achieve precise limit locking.

[0047] The reel is made of high-strength aluminum alloy and can be replaced with a diameter of 300-500mm according to the cable specifications. The inner wall of the reel is equipped with cable slots, the width of which is 0.5mm larger than the corresponding cable diameter to prevent slippage between layers when the cable is wound. The reel spindle is made of 45 steel with heat treatment, with a diameter ≥30mm and a compressive strength ≥600MPa to ensure that the spindle does not deform or wobble when winding large cross-section cables.

[0048] In this embodiment, the servo motor is connected to the reducer, the reducer is connected to the winding reel spindle, and the PLC controller outputs speed adjustment commands to the servo motor to directly control the rotation speed and torque of the winding reel, thereby realizing dynamic adjustment of the winding speed.

[0049] Specifically, the clutch control component enables the on / off control of the power mechanism and the reel spindle, providing a foundation for unobstructed cable pull-out and power recovery. In this embodiment, the core component is a DC24V electromagnetic clutch with a rated torque of 5 N·m, an engagement voltage of DC24V ± 10%, an engagement voltage of ≤ 5V, and a response time of ≤ 0.2s. The clutch and the reel spindle are connected by a flat key with a connection gap of ≤ 0.02mm to ensure that power transmission is slip-free.

[0050] In this embodiment, when the cable is pulled out, the encoder detects a pulse signal and transmits it to the PLC controller. The PLC controller determines that the pulling action has occurred and outputs a low-level signal. The electromagnetic clutch is de-energized and disengaged, and the power mechanism is disconnected from the reel spindle. The cable can then be pulled out by the operator without resistance. When the cable is retracted, the operator issues an "automatic retraction" command through the operation control module. After receiving the command, the PLC controller outputs a high-level signal, the electromagnetic clutch is energized and engaged, and the power mechanism drives the reel spindle to rotate through the reducer, thereby realizing the automatic power retraction of the cable.

[0051] Specifically, the tension monitoring component enables real-time acquisition and adaptive adjustment of tension during cable winding and unwinding, avoiding damage to the cable insulation layer due to excessive tension and loosening of the cable winding due to insufficient tension;

[0052] Two S-type pressure sensors are symmetrically installed on the side of the reel, with a range of 0-50N, a measurement accuracy of ±0.1N, and a data sampling frequency of 10Hz. The sensors communicate with the PLC controller in real time through an RS485 communication interface to ensure the timeliness and accuracy of tension data acquisition.

[0053] In this embodiment, the PLC controller has a built-in tension adaptive algorithm that calculates the target winding speed of the servo motor using a formula to control the tension and winding speed. The specific formula is as follows:

[0054] ;

[0055] in, The target winding speed of the servo motor, with a value range of 0.5-1.5 m / s;

[0056] The motor's reference speed is preset according to cable specifications; Φ10-15mm cable. =1.2m / s; Φ16-22mm cable =1.0m / s; Φ23-30mm cable =0.8m / s;

[0057] This is the speed adjustment coefficient, ranging from 0.4 to 0.7. The larger the cable diameter, the better. The larger the value, the more Φ10mm corresponds to =0.4; Φ30mm corresponds to =0.7;

[0058] The cable tension value is collected in real time by the pressure sensor;

[0059] To establish a benchmark for the upper limit of safe tension that cables can withstand during cable winding and unwinding, the material strength of commonly used cables in power plants must be strictly matched to ensure that the cable tension is always controlled within the safe range of 5-30N.

[0060] Specifically, the PLC controller receives data from the tension sensor every 0.1 seconds, calculates the target winding speed using the formula above, and then outputs the data to the servo driver via a PWM signal to dynamically adjust the motor speed.

[0061] when When the tension exceeds the upper limit, the PLC controller will... Down to It also triggers the alarm indicator light to flash at a frequency of 2Hz to alert the operator;

[0062] when When the tension exceeds the lower limit, the PLC controller will... Rise to Increase the winding speed to ensure the cable is wound tightly and avoids loosening or knotting;

[0063] when At that time, the tension was normal, and the PLC controller maintained [the position]. ;

[0064] and Pre-set according to cable specifications; the larger the cable diameter, the better. The larger the value.

[0065] Specifically, the length measuring component enables precise measurement, preset, and limit locking of the cable pull-out length, preventing excessively long cables from dragging and tangling the equipment, and excessively short cables from affecting the operating range. An incremental encoder with a resolution of 1024 lines / revolution is coaxially installed at the end of the reel spindle, with a power supply voltage of DC12-24V. The output signal is a two-phase A and B pulse, and the pulse frequency is proportional to the spindle speed. The encoder is connected to the high-speed counter interface of the PLC controller, with a counting frequency ≤100kHz, ensuring the accuracy of length measurement.

[0066] The PLC controller calculates the actual cable pull-out length by accumulating the number of pulses from the encoder. The calculation formula is as follows:

[0067] ;

[0068] in, The actual length of the cable pulled out is used, and the calculation result is rounded to two decimal places.

[0069] Accumulated pulse count for the encoder;

[0070] The effective diameter of the reel is preset based on the diameter of the compatible cable, and the value is reel diameter + 2 × cable radius.

[0071] For encoder resolution, P=1024 in this embodiment;

[0072] In this embodiment, i = 20, which is the gear ratio of the reducer.

[0073] In this embodiment, the operator inputs the preset pull-out length via the function keys on the operation control module. , The value range is 0-50m, with an accuracy of 0.1m. After input, the PLC controller will... The data is stored in an internal register, and the PLC controller performs real-time calculations during the cable pulling process. and To make a comparison, when At this time, the PLC controller outputs a deceleration signal to the servo motor, reducing the servo motor speed to a minimum. ×0.3, to achieve early deceleration;

[0074] when = At the same time, the PLC controller outputs two commands: one is to send a "fully engaged" signal to the electromagnetic clutch, and the other is to send an "emergency stop" signal to the servo motor. The spindle braking response time is ≤0.1s, which realizes precise locking of the cable length and prevents the cable from being pulled out or retracted.

[0075] If the cable pull-out length needs to be adjusted, the operator can re-enter the information through the operation control module. Alternatively, press the "unlock" button to release the lock and then continue pulling out or retracting the cable.

[0076] Specifically, the guidance and protection module includes a guidance component and a safety protection component. The guidance component constrains the cable winding and unwinding trajectory to prevent the cable from bending or scraping. The safety protection component provides multiple safety protections, including protection against accidental contact, overload jamming, and entanglement, reducing the operational safety risks at the power plant maintenance site.

[0077] The guiding assembly includes a guide wheel set and a guide bracket. The guide wheel set has two symmetrically arranged guide wheels installed at the cable outlet of the power supply panel. The wheel body is made of wear-resistant nylon with a Shore hardness ≥85D. The wheel groove width can be manually adjusted within the range of 10-30mm with an adjustment accuracy of ±0.5mm, adapting to cables of different diameters. The guide wheel shaft is made of stainless steel and equipped with a self-lubricating bearing, with a rotational resistance ≤0.5N, ensuring no jamming or wear when the cable is pulled out or retracted. The distance between the guide wheel set and the cable outlet is 15cm to prevent direct contact between the cable and the edge of the outlet, thus avoiding scratches.

[0078] The guide bracket is a rotatable guide bracket with a rotation angle of ±30°. The guide wheel assembly is installed on the rotatable guide bracket and can be flexibly adjusted according to the working angle at the power plant maintenance site to adapt to different cable pulling directions, reduce cable bending damage, and ensure smooth cable winding and unwinding.

[0079] In this embodiment, the safety protection components include an anti-accidental contact structure, an overload jamming protection structure, and an anti-tangling baffle, achieving multiple safety protections during the cable winding and unwinding process;

[0080] The cable outlet is equipped with a flip-type anti-accidental contact protective cover with a spring reset structure. It automatically opens when the cable is pulled out under tension and automatically closes when there is no tension after retraction. After closing, the device maintains an IP54 protection level to prevent accidental contact by non-operating personnel or entry of dust and water. The cable interface is equipped with an insulating sealing sleeve made of silicone rubber with a thickness of ≥5mm and a temperature resistance range of -40℃ to 100℃ to ensure the insulation performance at the interface and avoid the risk of leakage.

[0081] The built-in overload protection relay will immediately trip and cut off the main power supply when the supply current exceeds 1.2 times the rated current, thus achieving overload protection. During cable recycling, if the PLC controller detects tension... When the maximum safe tension is exceeded, or when the encoder has no pulse signal for 0.5 seconds and the cable is stuck, a stop command will be output immediately to control the servo motor to be powered off and the electromagnetic clutch to be disengaged. At the same time, an audible and visual alarm will be activated, with the buzzer loudness ≥85dB and the alarm light flashing red until the operator manually resets the machine after troubleshooting, in order to avoid motor overload damage or cable breakage.

[0082] An annular anti-winding baffle is installed on the inside of the reel. The baffle is made of high-strength ABS material and its height is 1.2 times the width of the reel. The inner edge of the baffle is rounded to avoid scratching the cable insulation layer. The gap between the baffle and the reel is ≤2mm to prevent the cable from overflowing from the edge of the reel during winding, causing knots and tangles.

[0083] Specifically, the operation control module serves as the human-machine interface between operators and equipment, enabling parameter setting, mode switching, visualization of operating status, and command input. Its installation location and structure are adapted to the operational needs of the power plant site.

[0084] The control panel features a waterproof and dustproof design with an IP65 protection rating. It is mounted on the side of the main frame at an operating height of 1.2m, allowing operators to stand and operate comfortably without bending over or raising their arms. A human-machine interface is provided, utilizing a 3.5-inch LCD screen with a resolution of 320×240 to display the actual cable pull-out length in real time. Actual tension Servo motor actual speed The system displays core information such as equipment operating mode, allowing operators to intuitively grasp the equipment's operating status. Function buttons include a power switch, numeric keys from 0 to 9, an confirmation key, an automatic retraction key, a manual retraction or pull-out bidirectional jog key, an unlock key, and a reset key. The buttons are made of silicone with a lifespan of ≥100,000 presses, meeting the needs of high-frequency operations in power plants. Status indicator lights include a solid green power indicator for normal power supply, a solid yellow working indicator for operational status, and a flashing red alarm indicator for triggered alarm mechanisms. These lights provide direct feedback on the equipment's operating status through color and status indicators.

[0085] In this embodiment, the operation control module supports three working modes: automatic retraction, manual jogging, and length preset. These modes can be switched using the "reset" button. Pressing the "automatic retraction" button activates the PLC controller, which dynamically adjusts the servo motor speed using a tension adaptive algorithm to achieve smooth cable retraction. When the encoder detects the accumulated pulse count... ,Right now When the cable is fully retracted, the PLC controller automatically cuts off the power to the servo motor and the main power supply, the power indicator light goes out, and the equipment returns to standby mode; pressing the "Manual Retraction" jog button will cause the servo motor to start moving at a speed of 100 km / h. The cable is retracted at a low speed and stops when the button is released; pressing the "Manual Pull Out" jog button causes the PLC controller to disengage the electromagnetic clutch, allowing the operator to manually pull out the cable in jogs. Each jog pull should be ≤0.5m to prevent uncontrolled cable extension; a preset length can be input via the numeric keypad. After pressing the "Confirm" button, the PLC controller stores the data and displays it on the screen. During the cable pulling process, the PLC controller automatically executes deceleration and limit locking logic to achieve precise length control. If changes are needed... You need to press the "Reset" key and re-enter the information.

[0086] Specifically, this invention uses an S7-200SMART PLC controller as the control core of the entire equipment. It centrally receives the data collected by each sensor and the instruction signals from the operation control module. After processing, it outputs control instructions to each execution module and feeds back the equipment operating status data to the display screen of the operation control module, so as to realize the coordinated work of each module. The core linkage logic follows the principles of power supply priority and safety protection priority.

[0087] In this embodiment, the PLC controller will only send a start permission signal to the automatic retractable module when both the circuit breaker and the leakage current protection device are closed and the PLC controller detects a normal power supply status signal. Otherwise, the automatic retractable module cannot be started, thus avoiding invalid operation of the equipment in the absence of power.

[0088] When any safety protection mechanism of the equipment is triggered (including power overload, cable jamming, excessive tension, abnormal anti-accidental contact protective cover, etc.), the PLC controller will immediately cut off the power supply unit and the automatic telescopic retraction unit to prioritize the personal safety of the operator and the integrity of the equipment and cables, and at the same time trigger the alarm mechanism to remind the operator.

[0089] The PLC controller synchronizes the tension, length, and speed data collected by all sensors, as well as the power supply status, operating mode, and fault information data of the equipment, to the LCD screen of the operation control module in real time, realizing status visualization. At the same time, the PLC controller is equipped with an RS485 communication interface, which supports uploading the above data to the power plant maintenance management system (optional), realizing remote monitoring and data traceability of the equipment, and adapting to the needs of intelligent management of power plants.

[0090] Example 2:

[0091] In this embodiment, a reel adapted for Φ16mm cables is used, with a diameter of 500mm, capable of holding 50m of Φ16mm cable; the servo motor power is 500W, and the base speed is... =1.0m / s, speed adjustment coefficient =0.4, safety tension benchmark value =15N; tension sensor monitoring range is 5-25N, encoder resolution is 1000 lines / revolution, length measurement accuracy is ±0.1m; preset pull-out length =15m;

[0092] First, the operator moves the equipment to the maintenance work location, depresses the caster brakes to secure the equipment, connects the industrial-grade three-phase four-pole plug to the power plant's industrial power supply, turns on the main power switch, and the power indicator light remains solid green, indicating that the PLC controller detects a normal power supply status; then, input is performed via the numeric keys on the operation control module. =15m and press the confirmation button. The PLC controller will... Stored in an internal register, the system initializes the encoder's accumulated pulse count. =0, by manually pulling out the cable, the encoder outputs a pulse signal in real time, and the PLC controller calculates in real time according to the length calculation formula. And displayed on the screen when When the servo motor automatically decelerates, At 15m, the electromagnetic clutch fully engages and the servo motor stops abruptly, locking the cable length. The cable is then connected to the maintenance equipment, initiating maintenance work. During operation, the tension sensor uploads tension data to the PLC controller every 0.1s. The PLC controller dynamically adjusts the winding speed according to a tension adaptive algorithm, maintaining the cable tension within the normal range of 10.5N-19.5N. The guide wheel assembly ensures a stable cable winding trajectory, preventing bending and scraping. After maintenance is completed, pressing the "Automatic Rewind" button activates the PLC controller, engaging the electromagnetic clutch and starting the servo motor. The speed is adjusted according to the tension algorithm. When the tension sensor detects… hour, It dropped to 0.88 m / s when detected. hour, The speed increased to 1.12 m / s when the encoder detected... When the cable is fully retracted, the PLC controller automatically cuts off the servo motor and main power supply, the power indicator light goes out, and the operator releases the caster wheel brakes to move the equipment to the next work point.

[0093] Example 3:

[0094] In this embodiment, the servo motor with an output torque of 50 N·m and the reel with a Φ25mm cable adapter are replaced, and the algorithm parameters, including the speed adjustment coefficient, are adjusted. Safety tension benchmark value The tension sensor monitoring threshold is adjusted to 10-30N, and the reference speed is... =0.9m / s; the remaining hardware structure and protection parameters remain unchanged, consistent with the routine maintenance procedure of Example 2. During the recovery process, the PLC controller follows the formula The servo motor speed is dynamically adjusted to ensure sufficient driving force during the recovery of large-section cables, preventing jamming and damage from excessive tension, and achieving the same precise control effect as conventional cables.

[0095] Example 4:

[0096] The core design of this invention is a combination of hardware structure and intelligent algorithm to achieve automatic cable extension and contraction, tension self-adaptation, and precise length control. Without changing the core design concept, some hardware selections or algorithm details can be replaced or adjusted to achieve the same purpose of the invention.

[0097] Specifically, a PID control algorithm can be used to replace the tension calculation formula of this invention. Tension self-adaptation can be achieved by adjusting the proportional coefficient, integral coefficient, and derivative coefficient. The core formula is:

[0098] ;

[0099] in, The target winding speed for the servo motor; The reference winding speed for the motor is preset according to the cable specifications. This is the proportionality coefficient; The integral coefficient; The differential coefficients are... , , All are pre-set according to cable specifications; This serves as a benchmark for the upper limit of cable safety tension. The actual cable tension value collected in real time by the sensor; This is the integral term representing the difference between the actual tension and the reference tension. This is the differential term of the difference between the actual tension and the reference tension. This algorithm can achieve the same closed-loop control effect of tension and winding speed as the original formula.

[0100] A laser rangefinder can be used to replace the incremental encoder. The laser rangefinder directly detects the actual length of the cable pulled out and transmits the detection data to the PLC controller. The PLC controller achieves accurate length locking by comparing the data with a threshold. The original length calculation formula remains unchanged, only the data source is changed from the encoder pulse count to the direct detection value of the laser rangefinder.

[0101] Stepper motors can be used to replace servo motors. The speed and angle of the stepper motor can be controlled by the pulse signal output by the PLC controller. With the tension feedback data of the torque sensor, the tension adjustment and length control effect can be achieved in the same way as the original power mechanism, which can adapt to the power requirements of cables of different specifications.

[0102] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the content of the present invention's specification shall also be included within the scope of protection of the present invention.

Claims

1. An automatic cable recycling control system for thermal power plant maintenance, characterized in that: It includes a main frame and power supply module, an automatic telescopic retraction module, a guidance and protection module, an operation control module, and a PLC controller. The PLC controller is electrically connected to the main frame and power supply module, the automatic telescopic retraction module, the guidance and protection module, and the operation control module to realize the linkage control of each module. The main frame and power supply module provide the installation foundation, power supply and mobility functions for the device. Its outer shell is an insulated protective structure with built-in power supply components, a movable and fixed structure at the bottom, and adjustable handrails on both sides. The automatic telescopic retraction module is the core execution module of the device, including a power mechanism, a clutch control component, a tension monitoring component, and a length measuring component, which realizes the cable's resistance-free pull-out, power-driven retraction, adaptive tension adjustment, and accurate length measurement. The guiding and protection module includes a guiding component and a safety protection component, which guides and constrains the cable winding and unwinding, and provides multiple safety protections such as protection against accidental contact, overload jamming, and entanglement. The operation control module is equipped with a human-machine interface to realize the parameter setting, mode switching, status display and command input of the equipment. Its output terminal is electrically connected to the PLC controller to receive operation commands and transmit them to the PLC controller. The PLC controller serves as the control core, receiving data collected by the tension monitoring component and the length measuring component, as well as instruction signals from the operation control module. After processing, it outputs control instructions to each execution module and simultaneously feeds back equipment status data to the operation control module.

2. The automatic cable recycling control system for thermal power plant maintenance according to claim 1, characterized in that: The main frame and the power supply module have built-in circuit breakers and leakage protectors. The input end is equipped with an industrial-grade protective plug, and the output end is equipped with multiple power sockets with anti-misinsertion and dustproof covers. The status signals of the circuit breaker and leakage protector are transmitted to the PLC controller. The PLC controller only allows the automatic telescopic retraction module to start when both are closed. The movable and fixed structure is a caster wheel with a braking function.

3. The automatic cable recycling control system for thermal power plant maintenance according to claim 1, characterized in that: The power mechanism of the automatic telescopic retraction module includes a servo motor and a reducer. The servo motor is connected to the reducer, and the reducer is connected to the reel spindle. The reel has a replaceable structure and a cable slot on the inner wall. The servo motor supports dual-mode switching of position mode and speed mode. The speed mode is used when retracting, and the position mode is used when pulling out to the limit. The PLC controller outputs speed adjustment commands to the servo motor to realize dynamic control of the winding speed.

4. The automatic cable recycling control system for thermal power plant maintenance according to claim 1, characterized in that: The clutch control component of the automatic telescopic retraction module is connected to the reel spindle and electrically connected to the PLC controller. When the cable is pulled out, the PLC controller controls the clutch control component to de-energize and disengage, causing the power mechanism to disconnect from the reel spindle, allowing the cable to be pulled out autonomously without resistance. When the cable is retracted, the PLC controller controls the clutch control component to energize and engage, causing the power mechanism to drive the reel spindle to rotate through the reducer, thus realizing the power recovery of the cable.

5. The automatic cable recycling control system for thermal power plant maintenance according to claim 1, characterized in that: The tension monitoring component of the automatic telescopic retraction module includes symmetrically arranged tension sensors. These sensors are communicatively connected to a PLC controller, transmitting real-time cable tension data to the PLC controller at a preset frequency. The PLC controller has a built-in tension adaptive algorithm that calculates the target winding speed of the servo motor using a formula, achieving closed-loop control of tension and winding speed. The formula is as follows: ； in, The target winding speed of the servo motor, This is the reference speed for the motor. This is the speed adjustment coefficient. The cable tension value is collected in real time by the pressure sensor. This is the baseline value for the upper limit of cable safety tension.

6. The automatic cable recycling control system for thermal power plant maintenance according to claim 5, characterized in that: The PLC controller receives tension data every 0.1 seconds and substitutes it into the formula for calculation. Simultaneously, the tension threshold control logic is set as follows: when At that time, the PLC controller will Down to And trigger an alarm; when At that time, the PLC controller will Rise to ; when At that time, the PLC controller maintains ; and Pre-set according to cable specifications; the larger the cable diameter, the better. The larger the value.

7. The automatic cable recycling control system for thermal power plant maintenance according to claim 1, characterized in that: The length measuring component of the automatic telescopic retraction module includes an encoder coaxially connected to the reel spindle. The encoder is connected to a high-speed counter interface of the PLC controller. The PLC controller calculates the actual length of the cable pulled out by the cumulative pulse count of the encoder. The length calculation formula is as follows: ； in, This refers to the actual length of the cable pulled out. The number of cumulative pulses for the encoder. The effective diameter of the reel. For encoder resolution, This represents the gear ratio of the reducer.

8. The automatic cable recycling control system for thermal power plant maintenance according to claim 7, characterized in that: The operation control module supports preset cable pull-out length. , The data is stored in the PLC controller's internal registers. During the cable pulling process, the PLC controller will send the data in real time. and contrast; when At this time, the PLC controller outputs a deceleration signal to reduce the speed of the servo motor; when = At the same time, the PLC controller simultaneously controls the clutch control component to fully engage and the servo motor to stop, achieving precise locking of the cable length; To unlock, you can re-enter the information via the operation control module. Or press the unlock button.

9. The automatic cable recycling control system for thermal power plant maintenance according to claim 1, characterized in that: The guiding and protection module includes a rotatable guide bracket and a guide wheel assembly mounted on the bracket. The width of the guide wheel groove is adjustable to accommodate cables of different specifications. The safety protection components include an anti-accidental contact structure, an overload jamming protection structure, and an anti-tangling baffle, achieving multiple safety protections during cable winding and unwinding.

10. The automatic cable recycling control system for thermal power plant maintenance according to claim 1, characterized in that: The human-machine interface of the operation control module includes a display screen, function buttons and status indicator lights, enabling device parameter settings, working mode switching and visual display of operating status. The PLC controller synchronizes sensor-collected data and device status data to the display screen in real time and supports data upload to an external management system.

Images