Control system and control method for main water inlet ball valve of pumped storage unit

Abstract

The invention discloses a control system and a control method of a main water inlet ball valve of a pumped storage unit, which can realize automatic control and accurate monitoring of the main water inlet ball valve by introducing a signal input module and a signal output module in the control system and combining with a medium-pressure oil pressure system. The system not only can automatically adjust the on-off state of the ball valve according to an operation command, but also can control the input and the withdrawal of the bypass valve, the sealing device and the servomotor lock in real time, and ensures the safe operation of the main water inlet ball valve in different working states. The working sealing device and the overhauling sealing device are located on the near-unit side and the far-unit side of the ball valve respectively, effective sealing and lubrication can be provided in the opening or closing process of the ball valve, and the problem of poor sealing caused by a high-pressure oil pressure system is solved. Through the control system, the system can carry out fault early warning or abnormity processing according to real-time monitoring data, the response speed and safety of the system are greatly improved, the operation process is simplified, and the stability and reliability of the system are improved.

Description

Technical Field

[0001] The invention belongs to the field of water inlet ball valve control, and in particular, relates to a control system and a control method of a main water inlet ball valve of a pumped storage unit. Background Art

[0002] In a pumped storage power station, the main water inlet ball valve is a key device used to cut off the pressure water flow between the pump-turbine unit and the upstream side penstock, which is directly related to the safety and stable operation of the entire unit. It not only needs to achieve precise pressure water flow control during daily start-up and shutdown, but also must respond quickly in emergency situations, especially when an accident occurs, the upstream pressure water flow must be quickly cut off to prevent the pump-turbine unit from overspeeding, avoiding damage to the equipment or causing more serious safety hazards. The closing speed and accuracy of the main water inlet ball valve are crucial. Any delay or misoperation may cause damage to the unit or the expansion of the accident. Therefore, reliable operation control and precise valve action control are particularly important.

[0003] The operation of the traditional main water inlet ball valve mostly relies on manual or semi-automatic control, which has many problems. First, manual control is susceptible to human error or limited reaction speed, especially in accidents or emergencies, and it is impossible to respond quickly and effectively, resulting in a slow response speed. Secondly, although semi-automatic control has improved operational efficiency to a certain extent, it relies on some manual operation steps, and there are still problems of complex operation and poor coordination. Especially in high-pressure water flow environments, the safety hazards brought by manual or semi-automatic operation cannot be ignored. In addition, traditional systems are usually unable to achieve real-time monitoring of the main water inlet ball valve and related equipment, and it is difficult to provide real-time feedback and adjustment of the working status, sealing condition and pressure balance of the ball valve, resulting in a significant reduction in the reliability and safety of the system operation.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a control system for a main water inlet ball valve of a pumped storage unit, thereby solving the problems raised in the above-mentioned background technology.

[0006] In order to solve the above technical problems, the basic concept of the technical solution adopted by the present invention is:

[0007] A control system for a main water inlet ball valve of a pumped storage unit, comprising: a main water inlet ball valve for isolating a pressure water flow between a water pump turbine unit and an upstream side pressure steel pipe;

[0008] The medium pressure oil pressure system is connected to the main water inlet ball valve, provides a pressure of 50-64MPa, and operates the ball valve by driving the servomotor;

[0009] A working sealing device and a maintenance sealing device, which are respectively arranged on the near unit side and the far unit side of the ball valve, and both the working sealing device and the maintenance sealing device cooperate with the medium pressure oil pressure system to provide sealing and lubrication during the opening and closing process of the ball valve;

[0010] Signal input module, the signal input module is used to receive the main oil valve switch status, bypass valve status, working seal and maintenance seal status, relay lock status, main water inlet valve control mode and opening or closing command;

[0011] Signal output module: The signal output module is connected to the signal input module and is used to output control signals, output control commands for bypass valve switching, seal input or output, and relay lock, and at the same time feedback the working status and abnormal information of the main water inlet valve.

[0012] Optionally, the medium-pressure oil pressure system realizes the rotation of the ball valve through a relay, thereby opening or closing the main water inlet ball valve, and the diameter of the ball valve is 2-3 meters.

[0013] Optionally, during the opening and closing process of the main water inlet ball valve, the working sealing device and the inspection sealing device cooperate with the medium pressure oil pressure system in the following steps:

[0014] During the opening and closing process of the main water inlet ball valve, the working sealing device and the maintenance sealing device are respectively arranged on the near unit side and the far unit side of the ball valve, and work in coordination with the medium pressure oil pressure system. When the ball valve opening command is issued, the signal input module first triggers the working sealing device to withdraw from the near unit side, and the maintenance sealing device to withdraw from the far unit side at the same time, to ensure that the ball valve is not obstructed during the opening process. The medium pressure oil pressure system provides lubrication and support during the opening and closing process of the ball valve. During the opening process of the ball valve, the working bypass valve is opened, and the pressure before and after the main water inlet ball valve is balanced. After the ball valve is successfully opened and reaches the fully open position, the working sealing device and the maintenance sealing device are completely withdrawn. When the ball valve closing command is issued, the signal input module triggers the ball valve closing operation. After the ball valve is closed, the working sealing device is re-invested in the near unit side for sealing, and the maintenance sealing device is invested in the far unit side for sealing to ensure the closing sealing effect of the ball valve. During the entire operation process, the signal output module provides real-time feedback on the status of the working sealing device and the maintenance sealing device, and ensures that the medium pressure oil pressure system always provides lubrication support for the ball valve.

[0015] Optionally, before the signal input module transmits data to the signal output module, a hybrid model needs to be established, wherein the hybrid model includes an event-driven model and a time-driven model. The steps of establishing the hybrid model are:

[0016] The tasks in the system are divided into time-driven tasks and event-driven tasks, which is the basis for subsequent scheduling. Time-driven tasks are executed at fixed intervals according to a predetermined schedule; event-driven tasks are triggered when a specific event occurs;

[0017] After task classification, in order to ensure that time-driven tasks are executed at fixed time intervals, global clock synchronization is set. The global clock ensures the time consistency between the signal input module and the signal output module, and provides accurate scheduling time points for time-driven tasks;

[0018] Based on the global clock, a time-driven model is constructed after synchronization. A fixed time slice is allocated to each time-driven task through a time-triggered scheduling algorithm. The signal input module regularly transmits the status of the main water inlet ball valve, bypass valve, and sealing device according to the time schedule to ensure that the task is executed on time. The expression is: Among them, T sched (t) is the time-driven scheduling function, which represents the total number of tasks scheduled by the system at time t, i is the task index, which represents the i-th time-driven task, and W i Represents the weight or priority of the i-th task, which is used to determine the importance of the task or resource allocation in the scheduling algorithm. Δt i represents the time slice interval of the i-th task, that is, the task is repeated every Δt i The time period is executed once. is an indicator function whose value is 1 when time t is Δt i The task needs to be executed when it is an integer multiple of , otherwise it is 0. i When the time is a multiple of , task i will be triggered to execute, and n represents the total number of time-driven tasks in the system, that is, the total number of tasks that need to be scheduled;

[0019] At the same time, in order to handle emergencies, an event-driven model is built, event listeners are set, and the system status is continuously monitored. When the event conditions are met, the event-driven model activates the task through the priority scheduling algorithm, immediately interrupts the ongoing time-driven task, and handles the emergency. The expression is: E sched (t) is the event-driven scheduling function, which represents the system's scheduling of event-driven tasks at time t. It selects the event tasks that should be processed first according to the priority of all currently occurring events. is the priority of event i, which is used to indicate the urgency of the current event. is an event trigger indicator function, which is used to indicate whether event i is triggered at time t. If event i occurs at time t, then Otherwise, it is 0. m is the total number of events that may occur in the system, indicating the different types of emergency situations that the system monitors simultaneously. Indicates that among all the events currently occurring, the event with the highest priority will be scheduled, based on the priority weight The system automatically prioritizes the most urgent tasks;

[0020] Finally, the time-driven model and the event-driven model are combined to form a hybrid model. Under normal circumstances, the system executes tasks regularly according to the time schedule through the time-driven model; when an event is detected, the hybrid model switches to the event-driven mode and prioritizes emergency tasks. After the event task is completed, the system automatically returns to the time-driven mode and continues to execute the scheduled time-driven tasks, thereby ensuring the balance and dynamic switching between routine operations and emergencies. The expression is:

[0021]

[0022] Among them, M sched (t) is a hybrid scheduling function, which represents the overall scheduling decision of the system at time t. It determines whether the system should execute time-driven tasks or event-driven tasks according to whether an emergency event occurs. sched (t) is a time-driven scheduling function. When there is no emergency, routine tasks are executed according to the predetermined time schedule. sched (t) is an event-driven scheduling function. When an emergency event is detected, the system switches to event-driven mode and prioritizes emergency tasks. It is an event priority judgment formula used to determine whether an emergency event occurs at the current time t. If the result is 0, it means that no event occurs; if it is greater than 0, it means that there is at least one event, and the task to be processed is selected according to the maximum priority event.

[0023] Optionally, the signal input module and the signal output module establish a confirmation mechanism. After the data transmission is successful, the signal output module feeds back a confirmation signal. If the confirmation signal is not received within the specified time, the signal input module will retransmit the data. If a data transmission failure or system failure is detected, the event-driven task triggers the fault handling mechanism. After the fault is repaired, the system resumes the time-driven mode and continues to transmit data according to the schedule.

[0024] Optionally, when the main water inlet valve is in the fully open state and the unit is running, if no closing command is received but the full-open position signal of the main water inlet valve is detected to be lost, and after an appropriate delay, the system determines that the main water inlet valve is abnormally closed, and the water inlet ball valve immediately performs an emergency closing operation, wherein the emergency closing trigger conditions include the main PLC issuing an emergency ball valve closing command, the backup PLC issuing an emergency ball valve closing command, and the tail gate is not in the fully open position.

[0025] A control method for a main water inlet ball valve of a pumped storage unit includes a main water inlet valve opening process, a main water inlet valve closing process, a main water inlet valve abnormal closing judgment logic, and a main water inlet valve emergency closing control, wherein the main water inlet valve opening process includes the following steps:

[0026] Step A1: At the beginning, the system will first check whether there is a system fault. If there is a fault, the system will stop the process, display the fault information and prompt maintenance. If there is no fault, the process will continue;

[0027] Step A2: The system checks whether the guide vanes are completely closed. If the guide vanes are not closed, the system will not continue to operate and prompt the operator to manually check the guide vane status. After the guide vanes are closed, the next operation is continued;

[0028] Step A3: The system confirms whether the inspection bypass valve is fully opened. The opening of the bypass valve ensures that the pressures before and after the system can be balanced when operating the main water inlet valve. If the inspection bypass valve is not opened, the system issues an opening command and confirms that it is opened.

[0029] Step A4: Confirm that the control mode of the main water inlet valve is set to remote control. If the system is in local control mode, the process will be paused to prompt the operator to adjust the control mode to remote control;

[0030] Step A5: The system confirms whether the tail gate is fully opened. If the tail gate is not fully opened, the system will pause the operation and prompt the operator to check;

[0031] Step A6: The system issues a command to "withdraw the servomotor lock spindle" to ensure that the servomotor lock spindle has been withdrawn and the main water inlet valve is allowed to operate freely. If the lock spindle has not been withdrawn, the system will not continue;

[0032] Step A7: Open the working bypass valve and confirm that the pressure before and after the main water inlet valve is balanced. After the system confirms that the bypass valve is fully opened and the pressure is balanced, proceed to the next step;

[0033] Step A8: The system confirms that the working seal of the main water inlet valve is withdrawn from the valve position to avoid obstruction of valve operation. If the working seal is not completely withdrawn, the system will suspend the operation and prompt the operator;

[0034] Step A9: The system issues a command to open the main water inlet valve. At this time, the main water inlet valve slowly opens. The system monitors the valve opening in real time and stops the opening process when it confirms that the main water inlet valve reaches the fully open position.

[0035] Step A10: After the main water inlet valve is fully opened, the system issues a command to close the working bypass valve to ensure that the bypass valve is fully closed to prevent unnecessary water flow through the bypass valve, thus completing the valve opening process.

[0036] Optionally, the control method of the main water inlet valve closing process includes the following steps:

[0037] Step B1: The system first checks whether the main water inlet valve is fully open. If the main water inlet valve is not in the fully open state, the system will pause the operation and prompt the operator to check the valve opening;

[0038] Step B2: The system issues a command to close the main water inlet valve and closes the working bypass valve at the same time. During the closing process, the system will continue to monitor the valve opening and pressure conditions;

[0039] Step B3: When the system confirms that the main water inlet valve has reached the fully closed position, the system issues a stop command to end the valve closing operation;

[0040] Step B4: The system confirms that the working bypass valve is completely closed to prevent water from flowing through the bypass channel;

[0041] Step B5: The system confirms that the working sealing device is put into operation and ensures that the sealing device is in the correct position after the main water inlet valve is closed to prevent any water leakage;

[0042] Step B6: Finally, the system issues a command to engage the relay lock of the main water inlet valve to ensure that the valve is locked in place. After the lock is in place, the closing process is completed.

[0043] Optionally, the main water inlet valve abnormal closure judgment control method includes the following steps

[0044] Step C1: The system detects the fully open position signal of the main water inlet valve. If the fully open position signal is lost, the system starts the countdown and delays for a few seconds to confirm whether the signal is truly lost rather than a momentary fault;

[0045] Step C2: After the delay ends, the system checks whether it has received a closing command from the main water inlet valve. If there is no closing command, the system will continue to check;

[0046] Step C3: The system confirms whether the unit is in operation. If the unit is not in shutdown state, the system determines that it is in abnormal state.

[0047] Step C4: If the unit is in operation and the main water inlet valve is abnormally closed, the system starts a trip signal to protect the equipment and prevent damage to the unit.

[0048] Optionally, the main water inlet valve emergency closing control method includes the following steps:

[0049] Step D1: The system first detects whether the main monitoring PLC has issued an emergency shutdown command for the main water inlet valve. If the main PLC issues an emergency shutdown command, the system immediately executes the emergency shutdown;

[0050] Step D2: If the main PLC does not respond or fails, the backup PLC will take over control and issue an emergency command to close the main water inlet valve, which the system will execute immediately;

[0051] Step D3: Before executing the emergency closing command, the system confirms whether the tail gate is fully opened. If the tail gate is not fully opened, the system will pause the operation and prompt to check the status of the tail gate;

[0052] Step D4: After confirming that all conditions are met, the system performs an emergency shutdown operation and immediately closes the main water inlet valve to ensure the safety of the system and equipment.

[0053] After adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art. Of course, any product implementing the present invention does not necessarily need to achieve all the advantages described below at the same time:

[0054] The present invention can realize automatic control and precise monitoring of the main water inlet ball valve by introducing signal input and output modules in the control system in combination with a medium-pressure oil pressure system. The system can not only automatically adjust the switch state of the ball valve according to the operation command, but also control the input and output of the bypass valve, the sealing device and the relay lock spindle in real time to ensure the safe operation of the main water inlet ball valve under different working conditions. The working sealing device and the maintenance sealing device are respectively located on the near unit side and the far unit side of the ball valve, which can provide effective sealing and lubrication during the opening or closing process of the ball valve to prevent poor sealing problems caused by the high-pressure oil pressure system. Through this control system, the system can perform fault warning or abnormal processing based on real-time monitoring data, which greatly improves the response speed and safety of the system, simplifies the operation process, and improves the stability and reliability of the system.

[0055] The specific implementation modes of the present invention are further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The drawings described below are only some embodiments. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0057] In the figure:

[0058] Figure 1 The main water inlet valve opening flow chart;

[0059] Figure 2 Flow chart for closing the main water inlet valve;

[0060] Figure 3 Logic diagram for judging abnormal closure of main water inlet valve;

[0061] Figure 4 Circuit diagram for emergency shutoff of main water inlet valve.

[0062] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but are intended to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0063] The present invention will now be described in further detail with reference to the accompanying drawings.

[0064] See also Figure 1-4 As shown, in this embodiment, a control system of a main water inlet ball valve of a pumped storage unit is provided, comprising:

[0065] The main water inlet ball valve is used to cut off the pressure water flow between the pump turbine unit and the upstream side pressure steel pipe;

[0066] The medium pressure oil pressure system is connected to the main water inlet ball valve, provides a pressure of 50-64MPa, and operates the ball valve by driving the servomotor;

[0067] A working sealing device and a maintenance sealing device, which are respectively arranged on the near unit side and the far unit side of the ball valve, and both the working sealing device and the maintenance sealing device cooperate with the medium pressure oil pressure system to provide sealing and lubrication during the opening and closing process of the ball valve;

[0068] Signal input module, the signal input module is used to receive the main oil valve switch status, bypass valve status, working seal and maintenance seal status, relay status, main water inlet valve control mode and opening or closing command;

[0069] The signal output module is connected to the signal input module and is used to output control signals, output control commands for the bypass valve switch, seal input or output, and relay lock spindle, and at the same time feedback the working status and abnormal information of the main water inlet valve. The present invention can realize automatic control and precise monitoring of the main water inlet ball valve by introducing signal input and output modules in the control system and combining with the medium pressure oil pressure system. The system can not only automatically adjust the switch state of the ball valve according to the operation command, but also control the input and output of the bypass valve, the sealing device and the relay lock spindle in real time to ensure the safe operation of the main water inlet ball valve under different working conditions. The working sealing device and the maintenance sealing device are respectively located on the near unit side and the far unit side of the ball valve, which can provide effective sealing and lubrication during the opening or closing process of the ball valve to prevent poor sealing problems caused by the high pressure oil pressure system. Through this control system, the system can perform fault warning or abnormal processing according to real-time monitoring data, which greatly improves the response speed and safety of the system, simplifies the operation process, and improves the stability and reliability of the system.

[0070] In this embodiment, the medium-pressure oil pressure system realizes the rotation of the ball valve through the relay, thereby opening or closing the main water inlet ball valve, and the diameter of the ball valve is 2-3 meters.

[0071] During the opening and closing process of the main water inlet ball valve, the working seal device and the maintenance seal device work in coordination with the medium pressure oil pressure system as follows:

[0072] During the opening and closing process of the main water inlet ball valve, the working seal device and the maintenance seal device are respectively arranged on the near unit side and the far unit side of the ball valve, and work in coordination with the medium pressure oil pressure system. When the ball valve opening command is issued, the working seal and the maintenance seal device withdraw in sequence to ensure that the ball valve opens without hindrance. At the same time, the working bypass valve opens to balance the pressure before and after the main water inlet ball valve, and the lubrication device provides continuous support. After the ball valve is fully opened, the sealing device withdraws. When the ball valve is closed, the sealing device resumes work to ensure the sealing effect. During the whole process, the signal output module provides real-time feedback on the sealing status and abnormal information, and ensures that the medium pressure oil pressure system always provides support for the ball valve.

[0073] In this embodiment, before the signal input module transmits data to the signal output module, a hybrid model needs to be established, wherein the hybrid model includes an event-driven model and a time-driven model. The steps of establishing the hybrid model are:

[0074] The tasks in the system are divided into time-driven tasks and event-driven tasks, which is the basis for subsequent scheduling. Time-driven tasks are executed at fixed intervals according to a predetermined schedule, such as regularly transmitting the status of the main water inlet ball valve, bypass valve and sealing device; event-driven tasks are triggered when specific events (such as system abnormalities or emergency failures) occur, such as immediately transmitting the instruction to close the main water inlet ball valve when abnormal system pressure is detected; by dividing the tasks in the system into time-driven tasks and event-driven tasks, task scheduling is more organized and can clearly distinguish between routine tasks and emergency tasks. Such classification provides a basis for subsequent scheduling and reduces conflicts in task management, ensuring the stable execution of routine tasks and the priority processing of emergency tasks.

[0075] After task classification, in order to ensure that time-driven tasks are executed at fixed time intervals, global clock synchronization is set. The global clock ensures the time consistency between the signal input module and the signal output module, and provides accurate scheduling time points for time-driven tasks. Through the Precision Time Protocol (PTP), time-driven tasks can be executed on time according to the predetermined schedule; through global clock synchronization and Precision Time Protocol (PTP), the system can ensure the time consistency of the signal input module and the signal output module, and ensure that the time-driven tasks can be executed according to the precise time schedule, thereby realizing precise control and coordinated scheduling of the system.

[0076] Based on the global clock, a time-driven model is constructed after synchronization. A fixed time slice is allocated to each time-driven task through a time-triggered scheduling algorithm. The signal input module regularly transmits the status of the main water inlet ball valve, bypass valve, and sealing device according to the time schedule to ensure that the task is executed on time. The expression is: Among them, T sched (t) is the time-driven scheduling function, which represents the total number of tasks scheduled by the system at time i. This function determines which tasks are executed at the current time by checking the status of all time-driven tasks in the system. i is the task index, which represents the i-th time-driven task. There may be multiple time-driven tasks in the system, and each task is scheduled separately. W i Indicates the weight or priority of the i-th task, which is used to determine the importance of tasks or resource allocation in the scheduling algorithm. Among tasks, tasks with larger weights will be executed first. Δt i represents the time slice interval of the i-th task, that is, the task is repeated every Δt i The time period is executed once. is an indicator function whose value is 1 when time i is Δt i The task needs to be executed when it is an integer multiple of , otherwise it is 0. i When the time is a multiple of , task i will be triggered to execute, n represents the total number of time-driven tasks in the system, that is, the total number of tasks that need to be scheduled; through the time-driven model, the system can execute routine tasks according to the predetermined schedule, such as monitoring the status of the main water inlet ball valve, bypass valve and sealing device to ensure the timely execution of routine operations. The event-driven model can respond in time through the event trigger mechanism when a system abnormality or emergency failure occurs, give priority to emergency tasks, achieve rapid response to system abnormalities, and avoid system damage or further failure expansion.

[0077] At the same time, in order to handle emergencies, an event-driven model is built, event listeners are set, and the system status is continuously monitored. When the event conditions are met, the event-driven model activates the task through the priority scheduling algorithm, immediately interrupts the ongoing time-driven task, and handles the emergency. The expression is: E sched (t) is the event-driven scheduling function, which represents the system's scheduling of event-driven tasks at time t. It selects the event tasks that should be processed first according to the priority of all currently occurring events. is the priority of event i, which is used to indicate the urgency of the current event. The higher the priority of an event, the more urgent its processing task is. The system will respond to high-priority events first. is an event trigger indicator function, which is used to indicate whether event i is triggered at time t. If event i occurs at time t, then Otherwise, it is 0. m is the total number of events that may occur in the system, indicating the different types of emergency situations that the system monitors simultaneously. Indicates that among all the events currently occurring, the event with the highest priority will be scheduled, based on the priority weight The system automatically selects the most urgent tasks to be processed first; a priority scheduling algorithm is introduced in the event-driven model to ensure that the system prioritizes the most urgent tasks when multiple emergency events occur. This priority-based scheduling mechanism can reasonably allocate system resources when resources are limited, improve the efficiency of event response, and ensure the security and stability of the system.

[0078] Finally, the time-driven model and the event-driven model are combined to form a hybrid model. Under normal circumstances, the system executes tasks regularly according to the time schedule through the time-driven model; when an event is detected, the hybrid model switches to the event-driven mode and prioritizes emergency tasks. After the event task is completed, the system automatically returns to the time-driven mode and continues to execute the scheduled time-driven tasks, thereby ensuring the balance and dynamic switching between routine operations and emergencies. The expression is:

[0079]

[0080] Among them, M sched (t) is a hybrid scheduling function, which represents the overall scheduling decision of the system at time t. It determines whether the system should execute time-driven tasks or event-driven tasks according to whether an emergency event occurs. sched (t) is the time-driven scheduling function. When there is no emergency, the system executes routine tasks according to the predetermined time schedule. sched (t) is an event-driven scheduling function. When an emergency event is detected, the system switches to event-driven mode and prioritizes emergency tasks. It is an event priority judgment formula, which is used to determine whether an emergency event occurs at the current time t. If the result is 0, it means that no event occurs; if it is greater than 0, it means that there is at least one event, and the task to be processed is selected according to the maximum priority event; the hybrid model allows the system to execute tasks through the time-driven model under normal circumstances, and switch to the event-driven mode to process high-priority tasks in an emergency. After the task processing is completed, the system can automatically return to the time-driven mode and continue to execute regular tasks. This dynamic switching mechanism not only ensures the daily stable operation of the system, but also ensures a rapid response in emergencies, balancing the needs between regular operations and emergency handling.

[0081] Working mechanism of the expression: When the system does not detect any emergency events, all event indication functions Then the system is scheduled according to time drive T sched(t) Operation, which periodically performs scheduled tasks such as status data transmission and routine monitoring. If an emergency event (i.e. ), the system immediately switches to event-driven scheduling E sched (t), interrupt time driven task, give priority to emergency tasks, such as system abnormalities or equipment failures, once the event task processing is completed, the event indication function When it becomes 0 again, the system automatically returns to the time-driven mode T sced (t) and continue to perform routine tasks according to the original schedule.

[0082] The main water inlet ball valve control system of a pumped storage power station is responsible for managing the water flow between the pump-turbine unit and the upstream penstock. The system needs to ensure that routine operations (such as opening and closing the main water inlet ball valve) are carried out on time. At the same time, it also needs to take timely measures in the event of an emergency (such as abnormal system pressure or failure) to prevent equipment damage or accidents.

[0083] When the system is operating normally, the control system executes tasks regularly through a time-driven model. Specific examples include: every 5 seconds, the system automatically checks and records the opening of the main water inlet ball valve. Every 10 seconds, the system checks the status of the bypass valve and the operation of the sealing device. Every 30 seconds, the system monitors the water pressure and temperature in the system. During this process, the system's tasks are executed on time according to the predetermined schedule, which ensures that the system's regular operations can run as planned without lags or missed tasks.

[0084] When the system detects an abnormal situation, such as the system pressure suddenly exceeds the safety threshold, the main water inlet ball valve opening is abnormal, or the bypass valve status is abnormal, the system will immediately interrupt the current time-driven task through the event-driven model and give priority to emergency events. Specific examples include: when abnormal water pressure is detected, the system triggers an emergency command to close the main water inlet ball valve through the event listener to prevent excessive pressure from damaging the unit. If the opening signal of the main water inlet ball valve is lost, the system will automatically issue a command to close the valve to prevent unexpected water flow impact. If the switch position of the bypass valve is abnormal, the system will give priority to correcting the state of the bypass valve to maintain water flow balance. At this time, the event-driven model will immediately interrupt the current routine task being executed according to the priority of the event to ensure that the emergency task is handled first. For example, if the bypass valve status is abnormal and the regular opening check of the main water inlet ball valve is being performed at this time, the system will suspend the current inspection task and deal with the bypass valve problem instead.

[0085] Under normal circumstances, the system always regularly executes routine tasks (such as regularly monitoring the ball valve opening, bypass valve status, pressure and temperature, etc.) through the time-driven model. Once an emergency occurs (such as abnormal pressure or ball valve failure), the system immediately switches from time-driven mode to event-driven mode, giving priority to emergency situations (such as closing the ball valve or adjusting the bypass valve status). When the emergency is handled, the system automatically switches back to time-driven mode and continues to execute the original routine tasks.

[0086] In this embodiment, the signal input module and the signal output module establish a confirmation mechanism. After the data transmission is successful, the signal output module feeds back a confirmation signal. If the confirmation signal is not received within the specified time, the signal input module will retransmit the data. If a data transmission failure or system failure is detected, the event-driven task triggers the fault handling mechanism. After the fault is repaired, the system resumes the time-driven mode and continues to transmit data according to the schedule.

[0087] In this embodiment, when the main water inlet valve is in the fully open state and the unit is running, if no closing command is received but the fully open position signal of the main water inlet valve is detected to be lost, and after a suitable delay, the system determines that the main water inlet valve is abnormally closed, and then the water inlet ball valve immediately performs an emergency closing operation, wherein the emergency closing trigger conditions include the main PLC issuing an emergency closing ball valve command, the backup PLC issuing an emergency closing ball valve command, and the tail gate is not in the fully open position.

[0088] In this embodiment, the main water inlet ball valve control system has a remote control mode and a local control mode. In the remote control mode, the monitoring system remotely issues an instruction to open or close the ball valve, and the local control mode is completed by manual operation on site.

[0089] A control method for a main water inlet ball valve of a pumped storage unit includes a main water inlet valve opening process, a main water inlet valve closing process, a main water inlet valve abnormal closing judgment logic, and a main water inlet valve emergency closing control, wherein the main water inlet valve opening process includes the following steps:

[0090] Step A1: At the beginning, the system will first check whether there is a system fault. If there is a fault, the system will stop the process, display the fault information and prompt maintenance. If there is no fault, the process will continue;

[0091] Step A2: The system checks whether the guide vanes are completely closed. If the guide vanes are not closed, the system will not continue to operate and prompt the operator to manually check the guide vane status. After the guide vanes are closed, the next operation is continued;

[0092] Step A3: The system confirms whether the inspection bypass valve is fully opened. The opening of the bypass valve ensures that the pressures before and after the system can be balanced when operating the main water inlet valve. If the inspection bypass valve is not opened, the system issues an opening command and confirms that it is opened.

[0093] Step A4: Confirm that the control mode of the main water inlet valve is set to remote control. If the system is in local control mode, the process will be paused to prompt the operator to adjust the control mode to remote control;

[0094] Step A5: The system confirms whether the tail gate is fully opened. If the tail gate is not fully opened, the system will pause the operation and prompt the operator to check;

[0095] Step A6: The system issues a command to "withdraw the servomotor lock spindle" to ensure that the servomotor lock spindle has been withdrawn and the main water inlet valve is allowed to operate freely. If the lock spindle has not been withdrawn, the system will not continue;

[0096] Step A7: Open the working bypass valve and confirm that the pressure before and after the main water inlet valve is balanced. After the system confirms that the bypass valve is fully opened and the pressure is balanced, proceed to the next step;

[0097] Step A8: The system confirms that the working seal of the main water inlet valve is withdrawn from the valve position to avoid obstruction of valve operation. If the working seal is not completely withdrawn, the system will suspend the operation and prompt the operator;

[0098] Step A9: The system issues a command to open the main water inlet valve. At this time, the main water inlet valve slowly opens. The system monitors the valve opening in real time and stops the opening process when it confirms that the main water inlet valve reaches the fully open position.

[0099] Step A10: After the main water inlet valve is fully opened, the system issues a command to close the working bypass valve to ensure that the bypass valve is fully closed to prevent unnecessary water flow through the bypass valve, thus completing the valve opening process.

[0100] In this embodiment, the control method of the main water inlet valve closing process includes the following steps

[0101] Step B1: The system first checks whether the main water inlet valve is fully open. If the main water inlet valve is not in the fully open state, the system will pause the operation and prompt the operator to check the valve opening;

[0102] Step B2: The system issues a command to close the main water inlet valve and closes the working bypass valve at the same time. During the closing process, the system will continue to monitor the valve opening and pressure conditions;

[0103] Step B3: When the system confirms that the main water inlet valve has reached the fully closed position, the system issues a stop command to end the valve closing operation;

[0104] Step B4: The system confirms that the working bypass valve is completely closed to prevent water from flowing through the bypass channel;

[0105] Step B5: The system confirms that the working sealing device is put into operation and ensures that the sealing device is in the correct position after the main water inlet valve is closed to prevent any water leakage;

[0106] Step B6: Finally, the system issues a command to engage the relay lock of the main water inlet valve to ensure that the valve is locked in place. After the lock is in place, the closing process is completed.

[0107] In this embodiment, the main water inlet valve abnormal closure judgment control method includes the following steps

[0108] Step C1: The system detects the fully open position signal of the main water inlet valve. If the fully open position signal is lost, the system starts the countdown and delays for a few seconds to confirm whether the signal is truly lost rather than a momentary fault;

[0109] Step C2: After the delay ends, the system checks whether it has received a closing command from the main water inlet valve. If there is no closing command, the system will continue to check;

[0110] Step C3: The system confirms whether the unit is in operation. If the unit is not in shutdown state, the system determines that it is in abnormal state.

[0111] Step C4: If the unit is in operation and the main water inlet valve is abnormally closed, the system starts a trip signal to protect the equipment and prevent damage to the unit.

[0112] In this embodiment, the main water inlet valve emergency closing control method includes the following steps

[0113] Step D1: The system first detects whether the main monitoring PLC has issued an emergency shutdown command for the main water inlet valve. If the main PLC issues an emergency shutdown command, the system immediately executes the emergency shutdown;

[0114] Step D2: If the main PLC does not respond or fails, the backup PLC will take over control and issue an emergency command to close the main water inlet valve, which the system will execute immediately;

[0115] Step D3: Before executing the emergency closing command, the system confirms whether the tail gate is fully opened. If the tail gate is not fully opened, the system will pause the operation and prompt to check the status of the tail gate;

[0116] Step D4: After confirming that all conditions are met, the system performs an emergency shutdown operation and immediately closes the main water inlet valve to ensure the safety of the system and equipment.

[0117] The present invention is not limited to the above-mentioned embodiments. Anyone should be aware that any structural changes made under the enlightenment of the present invention, and any technical solutions that are the same or similar to the present invention, fall within the protection scope of the present invention. The technology, shape, and structural parts not described in detail in the present invention are all well-known technologies.

Claims

1. A control system for a main water inlet ball valve of a pumped storage unit, characterized in that: include: The main water inlet ball valve is used to cut off the pressure water flow between the pump turbine unit and the upstream side pressure steel pipe; The medium pressure oil pressure system is connected to the main water inlet ball valve, provides a pressure of 50-64MPa, and operates the ball valve by driving the servomotor; A working sealing device and a maintenance sealing device, which are respectively arranged on the near unit side and the far unit side of the ball valve, and both the working sealing device and the maintenance sealing device cooperate with the medium pressure oil pressure system to provide sealing and lubrication during the opening and closing process of the ball valve; Signal input module, the signal input module is used to receive the main oil valve switch status, bypass valve status, working seal and maintenance seal status, relay lock status, main water inlet valve control mode and opening or closing command; Signal output module: The signal output module is connected to the signal input module and is used to output control signals, output control commands for bypass valve switching, seal input or output, and relay lock, and at the same time feedback the working status and abnormal information of the main water inlet valve.

2. A control system for a main water inlet ball valve of a pumped storage unit according to claim 1, characterized in that: The medium-pressure oil pressure system realizes the rotation of the ball valve through a relay, thereby opening or closing the main water inlet ball valve, and the diameter of the ball valve is 2-3 meters.

3. A control system for a main water inlet ball valve of a pumped storage unit according to claim 1, characterized in that: During the opening and closing process of the main water inlet ball valve, the working seal device and the maintenance seal device work in coordination with the medium pressure oil pressure system as follows: During the opening and closing process of the main water inlet ball valve, the working sealing device and the maintenance sealing device are respectively arranged on the near unit side and the far unit side of the ball valve, and work in coordination with the medium pressure oil pressure system. When the ball valve opening command is issued, the working sealing device and the maintenance sealing device withdraw in sequence to ensure that the ball valve opens without hindrance. At the same time, the working bypass valve opens to balance the pressure before and after the main water inlet ball valve, and the lubrication device provides continuous support. After the ball valve is fully opened, the sealing device withdraws. When the ball valve is closed, the sealing device resumes work to ensure the sealing effect. During the whole process, the signal output module provides real-time feedback of the sealing status and abnormal information.

4. A control system for a main water inlet ball valve of a pumped storage unit according to claim 3, characterized in that: Before the signal input module transfers data to the signal output module, a hybrid model needs to be established. The hybrid model includes an event-driven model and a time-driven model. The steps to establish the hybrid model are: The tasks in the system are divided into time-driven tasks and event-driven tasks. Time-driven tasks are executed at fixed intervals according to a predetermined schedule; event-driven tasks are triggered when a specific event occurs. After task classification, in order to ensure that time-driven tasks are executed at fixed time intervals, global clock synchronization is set. The global clock ensures the time consistency between the signal input module and the signal output module, and provides accurate scheduling time points for time-driven tasks; Based on the global clock, a time-driven model is constructed after synchronization. A fixed time slice is allocated to each time-driven task through a time-triggered scheduling algorithm. The signal input module regularly transmits the status of the main water inlet ball valve, bypass valve, and sealing device according to the time schedule to ensure that the task is executed on time. The expression is: Among them, T sched (t) is the time-driven scheduling function, which represents the total number of tasks scheduled by the system at time t, i is the task index, which represents the i-th time-driven task, and W i Represents the weight or priority of the i-th task, which is used to determine the importance of the task or resource allocation in the scheduling algorithm. Δt i represents the time slice interval of the i-th task, that is, the task is repeated every Δt i The time period is executed once. is an indicator function whose value is 1 when time t is Δt i The task needs to be executed when it is an integer multiple of , otherwise it is 0. i When the time is a multiple of , task i will be triggered to execute, and n represents the total number of time-driven tasks in the system, that is, the total number of tasks that need to be scheduled; At the same time, in order to handle emergencies, an event-driven model is built, event listeners are set, and the system status is continuously monitored. When the event conditions are met, the event-driven model activates the task through the priority scheduling algorithm, immediately interrupts the ongoing time-driven task, and handles the emergency. The expression is: E sched (t) is the event-driven scheduling function, which represents the system's scheduling of event-driven tasks at time t. It selects the event tasks that should be processed first according to the priority of all currently occurring events. is the priority of event i, which is used to indicate the urgency of the current event. is an event trigger indicator function, which is used to indicate whether event i is triggered at time t. If event i occurs at time t, then Otherwise, it is 0. m is the total number of events that occurred in the system, indicating the different types of emergency situations that the system monitors simultaneously. Indicates that among all the events currently occurring, the event with the highest priority will be scheduled, based on the priority weight The system automatically prioritizes the most urgent tasks; Finally, the time-driven model and the event-driven model are combined to form a hybrid model. Under normal circumstances, the system executes tasks regularly according to the time schedule through the time-driven model; when an event is detected, the hybrid model switches to the event-driven mode and prioritizes emergency tasks. After the event task is completed, the system automatically returns to the time-driven mode and continues to execute the scheduled time-driven tasks, thereby ensuring the balance and dynamic switching between routine operations and emergencies. The expression is: Among them, M sched (t) is a hybrid scheduling function, which represents the overall scheduling decision of the system at time t. It determines whether the system should execute time-driven tasks or event-driven tasks according to whether an emergency event occurs. sched (t) is a time-driven scheduling function. When there is no emergency, routine tasks are executed according to the predetermined time schedule. sched (t) is an event-driven scheduling function. When an emergency event is detected, the system switches to event-driven mode and prioritizes emergency tasks. It is an event priority judgment formula used to determine whether an emergency event occurs at the current time t. If the result is 0, it means that no event occurs; if it is greater than 0, it means that there is at least one event, and the task to be processed is selected according to the maximum priority event.

5. A control system for a main water inlet ball valve of a pumped storage unit according to claim 4, characterized in that: The signal input module and the signal output module establish a confirmation mechanism. After successful data transmission, the signal output module feeds back a confirmation signal. If no confirmation signal is received within the specified time, the signal input module will retransmit the data. If data transmission failure or system failure is detected, the event-driven task triggers the fault handling mechanism. After the fault is repaired, the system resumes the time-driven mode and continues to transmit data according to the schedule.

6. A control system for a main water inlet ball valve of a pumped storage unit according to claim 5, characterized in that: When the main water inlet valve is in the fully open state and the unit is running, if no closing command is received but the full-open position signal of the main water inlet valve is detected to be lost, and after an appropriate delay, the system determines that the main water inlet valve is abnormally closed, and then the water inlet ball valve immediately performs an emergency closing operation. The emergency closing trigger conditions include the main PLC issuing an emergency closing ball valve command, the backup PLC issuing an emergency closing ball valve command, and the tail gate is not in the fully open position.

7. A method for controlling a main water inlet ball valve of a pumped storage unit using any one of claims 1 to 6, characterized in that: It includes the main water inlet valve opening process, the main water inlet valve closing process, the main water inlet valve abnormal closing judgment logic, and the main water inlet valve emergency closing control. Among them, the main water inlet valve opening process includes the following steps: Step A1: At the beginning, the system will first check whether there is a system fault. If there is a fault, the system will stop the process, display the fault information and prompt maintenance. If there is no fault, the process will continue; Step A2: The system checks whether the guide vanes are completely closed. If the guide vanes are not closed, the system will not continue to operate and prompt the operator to manually check the guide vane status. After the guide vanes are closed, the next operation is continued; Step A3: The system confirms whether the inspection bypass valve is fully opened. The opening of the bypass valve ensures that the pressures before and after the system can be balanced when operating the main water inlet valve. If the inspection bypass valve is not opened, the system issues an opening command and confirms that it is opened. Step A4: Confirm that the control mode of the main water inlet valve is set to remote control. If the system is in local control mode, the process will be paused to prompt the operator to adjust the control mode to remote control; Step A5: The system confirms whether the tail gate is fully opened. If the tail gate is not fully opened, the system will pause the operation and prompt the operator to check; Step A6: The system issues a "retreat the servomotor lock spindle" command to ensure that the servomotor lock spindle has been removed and allow the main water inlet valve to operate freely. If the lock spindle has not been removed, the system will not continue; Step A7: Open the working bypass valve and confirm that the pressure before and after the main water inlet valve is balanced. After the system confirms that the bypass valve is fully opened and the pressure is balanced, proceed to the next step; Step A8: The system confirms that the working seal of the main water inlet valve is withdrawn from the valve position to avoid obstruction of valve operation. If the working seal is not completely withdrawn, the system will suspend the operation and prompt the operator; Step A9: The system issues a command to open the main water inlet valve. At this time, the main water inlet valve slowly opens. The system monitors the valve opening in real time and stops the opening process when it confirms that the main water inlet valve reaches the fully open position. Step A10: After the main water inlet valve is fully opened, the system issues a command to close the working bypass valve to ensure that the bypass valve is fully closed to prevent unnecessary water flow through the bypass valve, thus completing the valve opening process.

8. A method for controlling a main water inlet ball valve of a pumped storage unit according to claim 1, characterized in that: The control method of the main water inlet valve closing process includes the following steps Step B1: The system first checks whether the main water inlet valve is fully open. If the main water inlet valve is not in the fully open state, the system will pause the operation and prompt the operator to check the valve opening; Step B2: The system issues a command to close the main water inlet valve and closes the working bypass valve at the same time. During the closing process, the system will continue to monitor the valve opening and pressure conditions; Step B3: When the system confirms that the main water inlet valve has reached the fully closed position, the system issues a stop command to end the valve closing operation; Step B4: The system confirms that the working bypass valve is completely closed to prevent water from flowing through the bypass channel; Step B5: The system confirms that the working sealing device is put into operation and ensures that the sealing device is in the correct position after the main water inlet valve is closed to prevent any water leakage; Step B6: Finally, the system issues a command to engage the relay lock of the main water inlet valve to ensure that the valve is locked in place. After the lock is in place, the closing process is completed.

9. A method for controlling a main water inlet ball valve of a pumped storage unit according to claim 1, characterized in that: The main water inlet valve abnormal closure judgment control method includes the following steps Step C1: The system detects the fully open position signal of the main water inlet valve. If the fully open position signal is lost, the system starts the countdown and delays for a few seconds to confirm whether the signal is truly lost rather than a momentary fault; Step C2: After the delay ends, the system checks whether it has received a closing command from the main water inlet valve. If there is no closing command, the system will continue to check; Step C3: The system confirms whether the unit is in operation. If the unit is not in shutdown state, the system determines that it is in abnormal state. Step C4: If the unit is in operation and the main water inlet valve is abnormally closed, the system starts a trip signal to protect the equipment and prevent damage to the unit.

10. A control system and control method for a main water inlet ball valve of a pumped storage unit according to claim 1, characterized in that: The main water inlet valve emergency closing control method includes the following steps Step D1: The system first detects whether the main monitoring PLC has issued an emergency shutdown command for the main water inlet valve. If the main PLC issues an emergency shutdown command, the system immediately executes the emergency shutdown; Step D2: If the main PLC does not respond or fails, the backup PLC will take over control and issue an emergency command to close the main water inlet valve, which the system will execute immediately; Step D3: Before executing the emergency closing command, the system confirms whether the tail gate is fully opened. If the tail gate is not fully opened, the system will pause the operation and prompt to check the status of the tail gate; Step D4: After confirming that all conditions are met, the system performs an emergency shutdown operation and immediately closes the main water inlet valve to ensure the safety of the system and equipment.

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