A top cover lifting control system and method for a hydroelectric power station giant unit

Abstract

This invention discloses a control system and method for lifting the roof of a giant hydropower unit, comprising: a signal acquisition module configured to acquire in real time the position signals of each support point of the roof, the hydraulic system pressure signals, and the oil tank status parameters; a core control module including a programmable logic controller (PLC) and a human-machine interface unit, wherein the PLC is communicatively connected to the signal acquisition module and programmed to execute synchronous compensation control logic; an execution drive module including a hydraulic pump control unit, a cooling motor control unit, and multiple servo motor drive units, each servo motor drive unit being connected to a relay at each support point of the roof; and a fault alarm unit activated in response to a fault judgment signal from the PLC. This invention effectively solves the technical problems of low synchronization accuracy, coarse fault response, and inaccurate endpoint alignment in the prior art.

Description

Technical Field

[0001] This invention relates to the field of hydropower station unit equipment control technology, and in particular to a control system and control method for lifting the top cover of a giant hydropower station unit. Background Technology

[0002] The roof of a giant hydropower unit serves as a core load-bearing and sealing component. Its installation and maintenance require lifting operations to meet stringent requirements of high load, high precision, and high safety. Currently, most mainstream roof lifting systems in the industry employ traditional, simple valve-controlled or purely mechanical linkage control schemes, lacking mature electro-hydraulic synchronous control mechanisms, resulting in significant technical shortcomings in the system.

[0003] Firstly, traditional valve control solutions rely on manual operation of valves to regulate hydraulic oil supply, which cannot achieve automated closed-loop control of the lifting process. Maintenance personnel need to observe the top cover status in real time and make manual adjustments, which is not only labor-intensive but also prone to uneven lifting speed and force imbalance due to human error. Pure mechanical linkage solutions transmit power through mechanical structures such as gears and connecting rods. Mechanical clearances and wear will further amplify control errors, making it difficult to adapt to the lifting accuracy requirements of giant top covers, which usually require ±1mm level. In severe cases, it may cause equipment hazards such as top cover deformation and seal damage.

[0004] Secondly, the existing system lacks synchronous control logic for electro-hydraulic coordination, making it impossible to accurately coordinate the consistent actions of multiple actuators such as relays and servo motors through the electrical system. This results in uneven stress on the top cover during multi-support lifting, which in turn affects the quality of unit installation or maintenance. At the same time, the system does not integrate digital status monitoring and fault early warning functions, and cannot provide real-time feedback on key parameters such as pressure, position, and oil status during the lifting process. This makes it difficult for maintenance personnel to predict equipment failures, further reducing operational safety and efficiency.

[0005] Therefore, developing an integrated electro-hydraulic synchronous control, automated operation, and high-precision monitoring top cover lifting electrical control system to solve the problems of low automation, insufficient control accuracy, and inadequate safety in traditional solutions has become an urgent need in the field of operation and maintenance of giant hydropower units. Summary of the Invention

[0006] To address the aforementioned shortcomings in existing technologies, this invention provides a control system and method for lifting the top cover of a giant hydropower unit, thereby solving the problems of low automation, insufficient control precision, and inadequate safety in traditional solutions.

[0007] To achieve the above objectives, this application provides a lifting control system for the top cover of a giant generating unit in a hydropower station, comprising: The signal acquisition module is configured to acquire in real time the position signals of each support point of the top cover, the pressure signals of the hydraulic system, and the status parameters of the oil tank. The core control module includes a programmable logic controller and a human-machine interface unit. The programmable logic controller communicates with the signal acquisition module and is programmed to execute synchronous compensation control logic. The execution drive module includes an oil pressure pump control unit, a cooling motor control unit, and multiple servo motor drive units, each of which is connected to a relay at each support point of the top cover. The fault alarm unit is activated in response to the fault judgment signal from the programmable logic controller; Among them, the core control module coordinates and controls the execution drive module. The core control module is configured to calculate the height deviation based on the position signals of each support point. When the height deviation exceeds the preset synchronization tolerance, it outputs a differentiated frequency adjustment command to the corresponding servo motor drive unit to dynamically compensate for the deviation and maintain the top cover level.

[0008] The signal acquisition module includes: Displacement sensors installed on the piston rods of each relay are used to detect the real-time position of each fulcrum. Pressure transmitters are used to monitor the system's oil supply pressure, oil pump outlet pressure, and servo motor opening / closing chamber pressure. Temperature and level sensors are installed inside the fuel tank; And fault detection components, used to detect filter blockage or motor overload.

[0009] The programmable logic controller is also configured to perform tiered start-stop control: Before starting the top cover lifting operation, a start command is sent to the oil pump control unit. After the system oil supply pressure reaches the preset working pressure, a run command is sent to the servo motor drive unit. After the top cover reaches the target position, an unloading command is first sent to the oil pump control unit, and a shutdown command is sent after a preset delay.

[0010] The cooling motor control unit is linked with the temperature sensor. The programmable logic controller is configured to start the cooling motor when the oil temperature T≥ T1 and stop the cooling motor when T≤ T2, where T1>T2, forming a temperature hysteresis control range [T2,T1].

[0011] A control method for lifting the top cover of a giant generating unit in a hydropower station, applied to the aforementioned control system, includes the following steps: Real-time acquisition of position signals at each support point of the top cover, system pressure signals, and oil tank status parameters; Calculate the height deviation between each support point based on the position signal; If the absolute value of the height deviation is greater than the preset synchronization tolerance threshold, then the current top cover movement direction and deviation change trend are further determined: When the top cover is in the process of rising and the height deviation continues to increase, stop the operation of all servo motors and restart the synchronous adjustment after the hydraulic system pressure stabilizes. When the top cover is descending and the height deviation exceeds the tolerance threshold, switch to low-speed descent mode and activate tilt warning; In the non-pause state, increase the pulse frequency to the servo motor drive unit corresponding to the lower height pivot point, or decrease the pulse frequency to the servo motor drive unit corresponding to the higher height pivot point. Repeat the above steps of deviation calculation and frequency adjustment until the height deviation converges to the tolerance range; At the same time, the start and stop of the oil pressure pump and cooling motor are coordinated and controlled according to the system pressure and oil temperature.

[0012] The dynamic adjustment of the servo motor pulse frequency specifically includes: No. i Each servo motor at time t pulse frequency Calculate using the following formula: ; In the formula: Based on the operating frequency; For the first i Height deviation of the fulcrum This represents the average height of the current support points. For at any time t Top cover i The current height value of each support point; This is the proportional gain coefficient. The differential gain coefficient; To control the cycle; This is the error value from the previous sampling time. And when At that time, Limiting ,in This represents the maximum permissible frequency offset.

[0013] If the following conditions are met within N consecutive control cycles: ; In the formula: This represents the maximum height deviation at the previous time t. This is the preset synchronization tolerance threshold; Let N be the deviation value before N control cycles. Preset small quantity; If an external obstruction or sensor malfunction is detected, a self-test process is triggered: the synchronous adjustment is paused, all fulcrums are controlled to move synchronously in the opposite direction by a distance D and then return to their original positions, and the deviation is monitored to see if it is recovered; if it is not recovered, the automatic mode is locked and manual intervention is prompted.

[0014] The servo motor is allowed to start only when the system oil supply pressure P(t) ≥ 16 MPa and the duration is ≥ 2 seconds. After the top cover is in place, send an unloading command first, and then stop the oil pump after a delay of n seconds.

[0015] The top cover lifting operation shall be immediately interrupted if any of the following fault conditions are detected: Filter blockage, low oil level, overloaded oil pump, or abnormal signal at any fulcrum position; Furthermore, before the interruption, the fault type and the current system load status are further determined: If it is a non-emergency fault and the top cover is stationary or at low speed, the current fine-tuning action can be completed before stopping the machine; If there is an emergency malfunction or the top cover is in a high-speed movement state, an emergency stop should be executed immediately.

[0016] When the top cover is close to the target position and the remaining stroke is less than the preset threshold S, if the current height deviation |Δh(t)|>H1, ​​then the endpoint rebound pre-compensation operation is performed: Pause the movement toward the target position, control all pivots to move synchronously in the opposite direction by a distance D1, and then immediately resume the forward movement to the target position; where D1 is the pre-compensation distance, H1 is the endpoint synchronization tolerance, and S is the proximity threshold; The pre-compensation operation utilizes the elastic rebound characteristics of the hydraulic system after unloading, so that the top cover naturally tends to a horizontal state after it is in place.

[0017] Compared with the prior art, the above-conceptual technical solution conceived in this application has the following beneficial effects: 1. This invention uses a programmable logic controller (PLC) to collect position signals from each support point in real time. Based on the height deviation Δh(t), it dynamically adjusts the frequency of each servo motor and introduces a composite judgment logic based on the direction of motion and deviation trend to avoid forced compensation when the deviation increases during ascent, thus preventing aggravated oscillations. Simultaneously, a frequency adjustment algorithm with differential feedforward is employed to suppress overshoot and improve disturbance rejection. Actual measurements show that during the entire lifting process of a 200-ton top cover, the synchronization error is stably controlled within ±1 mm, an order of magnitude improvement over the traditional hydraulic synchronization scheme of ±5 mm, completely eliminating mechanical failures such as guide jamming and scratches on sealing surfaces caused by asynchrony.

[0018] 2. This invention addresses the inherent elastic rebound characteristics of hydraulic systems by proposing a proactive reverse micro-motion of 2 mm before retracting when approaching the target position. Utilizing the system's physical characteristics for feedforward compensation, the top cover achieves a perfectly horizontal state after natural rebound. Maintenance personnel no longer need to perform time-consuming manual fine-tuning, significantly improving overhaul efficiency.

[0019] 3. This invention categorizes faults into emergency and non-emergency types and implements differentiated shutdown strategies based on the current speed status of the top cover, avoiding unnecessary interruptions caused by the one-size-fits-all emergency stop of existing technologies. For example, if the oil temperature is too high, the current fine-tuning action can be completed before shutdown, while if the oil level is too low, power is immediately cut off. This mechanism reduces unnecessary shutdowns while ensuring core safety, improving system availability and operational smoothness.

[0020] 4. By monitoring the characteristic of large and unchanging deviations over a long period, this invention allows the system to automatically identify mechanical jamming or sensor drift and trigger a 5mm synchronous micro-motion self-test process. If the deviation recovers, operation continues; otherwise, the automatic mode is locked and the fault point is accurately indicated. This function reduces fault location time from an average of 2 hours to less than 10 minutes, significantly reducing maintenance costs. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0022] Figure 1 This is a schematic diagram illustrating an embodiment of the present invention.

[0023] Figure 2 for Figure 1 Enlarged view of point A in the image.

[0024] Figure label: 1. Ring seat, 2. Top cover, 3. Flange ring, 4. Support rod, 5. Support plate, 6. Relay device, 7. Ear seat. Detailed Implementation

[0025] To more clearly illustrate the purpose, technical solution, and beneficial effects of this application, a further detailed description of this application is provided below in conjunction with illustrations and specific embodiments. It should be specifically noted that the specific embodiments described below are only for illustrating the technical content of this application and do not constitute a limitation on the scope of protection of this application.

[0026] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present 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, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present application. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0027] In the description of this invention, unless otherwise explicitly specified and limited, the term "connection" or similar designation indicating a connection between components should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection via an intermediate medium; it can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] Example 1: See Figure 1 This invention provides a lifting control system for the top cover of a giant hydropower unit, comprising: The signal acquisition module is configured to acquire in real time the position signals of each support point of the top cover 2, the hydraulic system pressure signals, and the oil tank status parameters. The core control module includes a programmable logic controller and a human-machine interface unit. The programmable logic controller communicates with the signal acquisition module and is programmed to execute synchronous compensation control logic. The execution drive module includes an oil pressure pump control unit, a cooling motor control unit, and multiple servo motor drive units, each of which is connected to the relay 6 at each support point of the top cover 2. The fault alarm unit is activated in response to the fault judgment signal from the programmable logic controller; Among them, the core control module coordinates and controls the execution drive module. The core control module is configured to calculate the height deviation based on the position signals of each support point. When the height deviation exceeds the preset synchronization tolerance, it outputs a differentiated frequency adjustment command to the corresponding servo motor drive unit to dynamically compensate for the deviation and maintain the top cover level.

[0029] Combination Figure 1 , 2Multiple support points are evenly distributed in a ring on the flange ring 3 on the outer circumference of the top cover 2 of the unit. In this scheme, there are 12 support points, and each support point includes multiple support rods 4. In this scheme, each support point includes four support rods 4. The lower end of the support rod 4 passes through the through hole on the flange ring 3 and is threaded and fixed to the ring seat 1. The upper ends of each support rod 4 of each support point are connected to a support plate 5. A relay 6 is installed on the upper side of the middle part of the support plate 5. The piston rod of the relay 6 extends outward. The end of the piston rod of the relay 6 is equipped with an ear seat 7, which is fixed to the outer circumference of the top cover 2. When the piston rod of each relay 6 retracts, the top cover 2 is lifted; conversely, the top cover 2 is lowered.

[0030] The programmable logic controller (PLC) periodically calculates the maximum height deviation Δh(t). When |Δh(t)| is greater than the threshold, the traditional average frequency drive is no longer used. Instead, the pulse frequency of each servo motor is dynamically adjusted according to the current motion direction v and the deviation change trend to ensure that the top cover remains horizontal throughout the lifting process, thus fundamentally avoiding guide jamming or damage to the sealing surface caused by asynchrony.

[0031] In this embodiment, the relay 6 uses a digital hydraulic cylinder. The hydraulic pump control unit is used to control the start, stop, loading, and unloading of the main hydraulic pump; the cooling motor control unit is used to regulate the hydraulic oil temperature to ensure that the system operates under safe thermal conditions; the servo motor drive unit on the relay 6 is used to convert the synchronous control commands of the PLC into precise mechanical motion, realizing high-precision coordinated lifting of multiple fulcrums.

[0032] Furthermore, the signal acquisition module includes: Displacement sensors installed on the piston rods of each relay are used to detect the real-time position of each fulcrum. Pressure transmitters are used to monitor the system's oil supply pressure, oil pump outlet pressure, and servo motor opening / closing chamber pressure. Temperature and level sensors are installed inside the fuel tank; And fault detection components, used to detect filter blockage or motor overload.

[0033] Furthermore, the programmable logic controller is also configured to perform tiered start-stop control: Before starting the top cover lifting operation, a start command is sent to the oil pump control unit. After the system oil supply pressure reaches the preset working pressure, a run command is sent to the servo motor drive unit. After the top cover reaches the target position, an unloading command is first sent to the oil pump control unit, and a shutdown command is sent after a preset delay.

[0034] Staged start-stop control is crucial for ensuring system safety. After the operator clicks the "Up" button on the touchscreen of the human-machine interface unit, the PLC first closes the main contactor of the hydraulic pump and starts the loading solenoid valve. Subsequently, the PLC continuously monitors the system oil supply pressure P(t). Only when P(t) ≥ 16MPa, which is the critical pressure for the hydraulic system to establish sufficient rigidity, and below this value, the relay response is delayed, and this state lasts for no less than 2 seconds, does the PLC send enable and run commands to the 12 servo motor drivers. Conversely, when the top cover reaches the target position, after confirmation by the preset height value or mechanical limit switch, the PLC immediately outputs a 24VDC signal to the unloading solenoid valve to cut off the high-pressure oil supply; at the same time, an 8-second delay timer is started to ensure that the residual pressure in the pipeline is completely released; after the delay ends, the PLC disconnects the power supply to the hydraulic pump contactor coil. This timing effectively prevents the motor from running dry under no pressure or the top cover from sliding down due to sudden pressure loss.

[0035] In this embodiment, the cooling motor control unit is linked with the temperature sensor, and the programmable logic controller is configured to start the cooling motor when the oil temperature T ≥ T1 and stop the cooling motor when T ≤ T2, where T1>T2, forming a temperature hysteresis control interval [T2, T1].

[0036] The cooling control strategy integrates both absolute temperature value and rate of change criteria. The PLC reads the PT100 signal every 100ms to calculate the current oil temperature T and the temperature rise rate R(t). When T(t)≥55°C and R(t)>2°C / min, it indicates sudden overheating. If the cooler is blocked or the load surges, the PLC immediately closes the cooling motor contactor and displays a "high temperature warning" on the touch screen.

[0037] Specifically, if T≥55℃ but R(t)≤2℃ / min, indicating a slow temperature rise, a 30-second delay is initiated to avoid frequent start-stop due to short-term operating condition fluctuations; when T(t)≤45°C, the PLC disconnects the cooling motor.

[0038] Example 2: A control method for lifting the top cover of a giant generating unit in a hydropower station, applied to the control system described in Example 1, includes the following steps: Real-time acquisition of position signals at each support point of the top cover, system pressure signals, and oil tank status parameters; Calculate the height deviation between each support point based on the position signal; If the absolute value of the height deviation is greater than the preset synchronization tolerance threshold, then the current top cover movement direction and deviation change trend are further determined: When the top cover is in the process of rising and the height deviation continues to increase, stop the operation of all servo motors and restart the synchronous adjustment after the hydraulic system pressure stabilizes. When the top cover is descending and the height deviation exceeds the tolerance threshold, switch to low-speed descent mode and activate tilt warning; In the non-pause state, increase the pulse frequency to the servo motor drive unit corresponding to the lower height pivot point, or decrease the pulse frequency to the servo motor drive unit corresponding to the higher height pivot point. Repeat the above steps of deviation calculation and frequency adjustment until the height deviation converges to the tolerance range; At the same time, the start and stop of the oil pressure pump and cooling motor are coordinated and controlled according to the system pressure and oil temperature.

[0039] Specifically, the position signals of each support point are collected in real time. System pressure P(t) and oil temperature T(t); Calculate the current maximum height deviation ; If |Δh(t)|>H0, then further determine the trend of the top cover's movement direction v and the deviation: If v>0 and Δh(t) - Δh(t - Δt)>δ, then pause the operation of all servo motors and restart the synchronous adjustment after the hydraulic system pressure stabilizes; Otherwise, the pulse frequency of the corresponding servo motor is dynamically adjusted based on the deviation between the height of each support point and the average height. Repeat the above steps until |Δh(t)| ≤ H0; Specifically, dynamically adjusting the servo motor pulse frequency includes: No. i Each servo motor at time t pulse frequency Calculate using the following formula: ; In the formula: Based on the operating frequency; For the first i Height deviation of the fulcrum This represents the average height of the current support points. For at any time t Top cover i The current height value of each support point; This is the proportional gain coefficient. The differential gain coefficient; To control the cycle; This is the error value from the previous sampling time. And when At that time, Limiting ,in This represents the maximum permissible frequency offset.

[0040] If the following conditions are met within N consecutive control cycles: and ; In the formula: This represents the maximum height deviation at the previous time t. This is the preset synchronization tolerance threshold; Let N be the deviation value before N control cycles. Preset small quantity; If an external obstruction or sensor malfunction is detected, a self-test process is triggered: the synchronous adjustment is paused, all fulcrums are controlled to move synchronously in the opposite direction by a distance D and then return to their original positions, and the deviation is monitored to see if it is recovered; if it is not recovered, the automatic mode is locked and manual intervention is prompted.

[0041] The self-test logic for the jamming mechanism runs continuously during the synchronous adjustment process. The PLC monitors the data for three consecutive cycles. If the conditions are consistently met... and If this is not detected, a self-check is triggered. The self-check process is as follows: pause synchronization adjustment, send a unified reverse command to all 12 servo motors, move, immediately switch to a forward command, and return to the original position. If after returning... If the value is still greater than 2mm, it is determined to be a mechanical jam or sensor failure. The PLC will lock in automatic mode and display an abnormality on the touch screen.

[0042] The servo motor is allowed to start only when the system oil supply pressure P(t) ≥ 16 MPa and the duration is ≥ 2 seconds. After the top cover is in place, send an unloading command first, and then stop the oil pump after a delay of n seconds.

[0043] Experiments show that when the oil supply pressure is <15MPa, the relay start-up delay is >200ms, causing the synchronization error to expand rapidly; while when the pressure is ≥16MPa, the response delay is <50ms. A 2-second duration ensures pressure stability and eliminates transient fluctuations during startup. The 8-second delay at shutdown is calculated based on the pipeline volume: the total system volume is approximately 120L, the unloading valve flow rate is 80L / min, and the theoretical pressure relief time is approximately 90 seconds. However, due to residual elastic energy, the pressure actually drops to a safe value after 8 seconds, sufficient to ensure safe shutdown.

[0044] The top cover lifting operation shall be immediately interrupted if any of the following fault conditions are detected: Filter blockage, low oil level, overloaded oil pump, or abnormal signal at any fulcrum position; Furthermore, before the interruption, the fault type and the current system load status are further determined: If it is a non-emergency fault and the top cover is stationary or at low speed, the current fine-tuning action can be completed before stopping the machine; If there is an emergency malfunction or the top cover is in a high-speed movement state, an emergency stop should be executed immediately.

[0045] The specific execution of fault-based shutdown relies on the PLC's internal state machine. Taking an oil temperature of 60℃ as an example: after the PLC detects T≥60℃, it displays a "non-emergency fault" flag but does not stop the current operation; shutdown is only executed after the current lifting cycle is completed. However, if the position signal is lost, an "emergency fault" flag is immediately triggered, and a hard emergency stop is executed regardless of the current speed. The speed threshold v0=5mm / s was determined through on-site debugging: below this value, the kinetic energy is small, and a flexible shutdown will not cause position deviation.

[0046] When the top cover is close to the target position and the remaining stroke is less than the preset threshold S, if the current height deviation |Δh(t)|>H1, ​​then the endpoint rebound pre-compensation operation is performed: Pause the movement toward the target position, control all pivots to move synchronously in the opposite direction by a distance D1, and then immediately resume the forward movement to the target position; where D1 is the pre-compensation distance, H1 is the endpoint synchronization tolerance, and S is the proximity threshold; The pre-compensation operation utilizes the elastic rebound characteristics of the hydraulic system after unloading, so that the top cover naturally tends to a horizontal state after it is in place.

[0047] Specifically, when the remaining travel of the top cover is <5mm and |Δh(t)|>1mm, the PLC pauses its movement towards the target position and instead controls all fulcrums to descend synchronously by 2mm; after 200ms, it immediately resumes the upward command to the target position. After the top cover stops supplying oil, due to the elastic deformation of the pipeline, it will slowly rebound by 1.5-2.2mm within 5 minutes. After a pre-compensation of 2mm, the rebound exactly cancels out the initial deviation, making the final static state Δh≤0.5mm.

[0048] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0049] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A lifting control system for the top cover of a giant generating unit in a hydropower station, characterized in that, include: The signal acquisition module is configured to acquire in real time the position signals of each support point of the top cover, the pressure signals of the hydraulic system, and the status parameters of the oil tank. The core control module includes a programmable logic controller and a human-machine interface unit. The programmable logic controller communicates with the signal acquisition module and is programmed to execute synchronous compensation control logic. The execution drive module includes an oil pump control unit, a cooling motor control unit, and multiple servo motor drive units. Each servo motor drive unit is connected to the relay (6) at each support point of the top cover (2). The fault alarm unit is activated in response to the fault judgment signal from the programmable logic controller; Among them, the core control module coordinates and controls the execution drive module. The core control module is configured to calculate the height deviation based on the position signals of each support point. When the height deviation exceeds the preset synchronization tolerance, it outputs a differentiated frequency adjustment command to the corresponding servo motor drive unit to dynamically compensate for the deviation and maintain the top cover level.

2. The hydropower station giant generator unit top cover lifting control system according to claim 1, characterized in that, The signal acquisition module includes: Displacement sensors installed on the piston rods of each relay are used to detect the real-time position of each fulcrum. Pressure transmitters are used to monitor the system's oil supply pressure, oil pump outlet pressure, and servo motor opening / closing chamber pressure. Temperature and level sensors are installed inside the fuel tank; And fault detection components, used to detect filter blockage or motor overload.

3. The lifting control system for the top cover of a giant hydropower unit according to claim 1, characterized in that, The programmable logic controller is also configured to perform tiered start-stop control: Before the top cover lifting operation is started, a start command is sent to the oil pump control unit. After the system oil supply pressure reaches the preset working pressure, a run command is sent to the servo motor drive unit of the relay (6). After the top cover reaches the target position, an unloading command is first sent to the oil pump control unit, and a shutdown command is sent after a preset delay.

4. The hydropower station giant generator unit top cover lifting control system according to claim 1, characterized in that, The cooling motor control unit is linked with the temperature sensor. The programmable logic controller is configured to start the cooling motor when the oil temperature T ≥ T1 and stop the cooling motor when T ≤ T2, where T1>T2, forming a temperature hysteresis control range [T2, T1].

5. A control method for lifting the top cover of a giant generating unit in a hydropower station, applied to the control system as described in any one of claims 1 to 4, characterized in that, Includes the following steps: Real-time acquisition of position signals at each support point of the top cover, system pressure signals, and oil tank status parameters; Calculate the height deviation between each support point based on the position signal; If the absolute value of the height deviation is greater than the preset synchronization tolerance threshold, then the current top cover movement direction and deviation change trend are further determined: When the top cover is in the process of rising and the height deviation continues to increase, stop the operation of all servo motors and restart the synchronous adjustment after the hydraulic system pressure stabilizes. When the top cover is descending and the height deviation exceeds the tolerance threshold, switch to low-speed descent mode and activate tilt warning; In the non-pause state, increase the pulse frequency to the servo motor drive unit corresponding to the lower height pivot point, or decrease the pulse frequency to the servo motor drive unit corresponding to the higher height pivot point. Repeat the above steps of deviation calculation and frequency adjustment until the height deviation converges to the tolerance range; At the same time, the start and stop of the oil pressure pump and cooling motor are coordinated and controlled according to the system pressure and oil temperature.

6. The control method according to claim 5, characterized in that, The dynamic adjustment of the servo motor pulse frequency specifically includes: No. i Each servo motor at time t pulse frequency Calculate using the following formula: ； In the formula: Based on the operating frequency; For the first i Height deviation of the fulcrum This represents the average height of the current support points. For at any time t Top cover i The current height value of each support point; This is the proportional gain coefficient. The differential gain coefficient; To control the cycle; This is the error value from the previous sampling time. And when At that time, Limiting ,in This represents the maximum permissible frequency offset.

7. The control method according to claim 5, characterized in that, If the following conditions are met within N consecutive control cycles: ； In the formula: This represents the maximum height deviation at the previous time t. This is the preset synchronization tolerance threshold; Let N be the deviation value before N control cycles. Preset small quantity; If an external obstruction or sensor malfunction is detected, a self-test process is triggered: the synchronous adjustment is paused, all fulcrums are controlled to move synchronously in the opposite direction by a distance D and then return to their original positions, and the deviation is monitored to see if it is recovered; if it is not recovered, the automatic mode is locked and manual intervention is prompted.

8. The control method according to claim 5, characterized in that, The servo motor is allowed to start only when the system oil supply pressure P(t) ≥ 16 MPa and the duration is ≥ 2 seconds. After the top cover is in place, send an unloading command first, and then stop the oil pump after a delay of n seconds.

9. The control method according to claim 5, characterized in that, The top cover lifting operation shall be immediately interrupted if any of the following fault conditions are detected: Filter blockage, low oil level, overloaded oil pump, or abnormal signal at any fulcrum position; Furthermore, before the interruption, the fault type and the current system load status are further determined: If it is a non-emergency fault and the top cover is stationary or at low speed, the current fine-tuning action can be completed before stopping the machine; If there is an emergency malfunction or the top cover is in a high-speed movement state, an emergency stop should be executed immediately.

10. The control method according to claim 5, characterized in that, When the top cover is close to the target position and the remaining stroke is less than the preset threshold S, if the current height deviation |Δh(t)|>H1, ​​then the endpoint rebound pre-compensation operation is performed: Pause the movement toward the target position, control all pivots to move synchronously in the opposite direction by a distance D1, and then immediately resume the forward movement to the target position; where D1 is the pre-compensation distance, H1 is the endpoint synchronization tolerance, and S is the proximity threshold; The pre-compensation operation utilizes the elastic rebound characteristics of the hydraulic system after unloading, so that the top cover naturally tends to a horizontal state after it is in place.

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