Method for monitoring and controlling cylindrical valve of hydroelectric generating set

Abstract

The invention provides a monitoring and controlling method for a cylindrical valve of a hydroelectric generating set. The monitoring and controlling method comprises the steps that stroke data of a servomotor are collected in real time through a displacement sensor; calculating the stroke deviation between the actual stroke of each servomotor and the expected stroke given value; controlling a proportional valve according to the stroke deviation, and adjusting the pressure oil supply flow in each servomotor cavity in real time to realize synchronous control of each servomotor in the opening and closing process of the cylindrical valve; in the opening or closing process of the cylindrical valve, the maximum stroke deviation of the servomotor is obtained in real time, the maximum stroke deviation is compared with the set deviation, the servomotor is switched between forward movement and reverse movement, and the blocking fault of the cylindrical valve is judged. According to the method provided by the invention, accurate control and fault accurate positioning can be carried out when jamming occurs in the whole operation process of the cylindrical valve of the hydroelectric generating set, and fault data when jamming occurs can be collected, so that operation and maintenance workers can conveniently check and process in time.

Description

Technical Field

[0001] The invention relates to the technical field of control of cylindrical valves of hydroelectric generator sets, and in particular to a monitoring and control method of cylindrical valves of hydroelectric generator sets. Background Art

[0002] The cylindrical valve of the hydropower unit is a circular gate valve installed between the fixed guide vane and the movable guide vane of the turbine. When the unit fails to run away or the water guide mechanism fails and cannot be closed, the dynamic water closing cylindrical valve can be used to shut down the unit to avoid accidents. After the guide vane is closed during normal shutdown, the cylindrical valve can be closed by static water to prevent the guide vane from being damaged by long-term cavitation and silt wear caused by high-speed water flow, saving the time for emptying and filling the water inlet pipe, reducing water loss and start-up and shutdown time. At present, the cylindrical valve is generally operated by 6 straight cylinder servomotors, and the electrical hydraulic / digital cylinder synchronous control system is used to ensure that the movement deviation of each servomotor is within the allowable range and does not cause jamming.

[0003] However, the existing cylindrical valve synchronous control stability is poor, the start-up and shutdown success rate is relatively low; and there is a lack of complete control strategies when the valve body is stuck during movement and real-time monitoring methods when a sticking fault occurs. This is not conducive to operation and maintenance personnel to determine the cause of the fault in the first time and to deal with it quickly. The cause of the fault cannot be quickly found to restore the normal operation of the equipment, thereby affecting the normal start-up and shutdown of the unit and even causing serious water machine accidents. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0005] To this end, the present invention provides a monitoring and control method for a cylindrical valve of a hydropower unit.

[0006] The present invention provides a monitoring and control method for a cylindrical valve of a hydropower unit, wherein the cylindrical valve is controlled to be opened and closed by a hydraulic system, wherein the hydraulic system at least comprises a plurality of servomotors, a main pressure regulating valve and a proportional valve, wherein the servomotor is used to drive the cylindrical valve to be opened and closed by a hydraulic method, the main pressure regulating valve is used to control a pipeline for conveying pressure oil to the servomotor, and the proportional valve is used to adjust the oil supply flow of each servomotor; the method comprises:

[0007] Use displacement sensors to collect the travel data of the relay in real time;

[0008] Calculate the travel deviation between the actual travel of each servomotor and the given value of the expected travel;

[0009] The proportional valve is controlled according to the stroke deviation, and the pressure oil supply flow rate in each servomotor cavity is adjusted in real time to achieve synchronous control of each servomotor during the opening and closing process of the cylindrical valve;

[0010] During the opening or closing process of the cylindrical valve, the maximum stroke deviation of the relay is obtained in real time, and the maximum stroke deviation is compared with the set deviation, so that the relay is switched between forward movement and reverse movement, and the cylindrical valve sticking failure is determined; wherein the forward movement is a movement consistent with the current switch valve command movement direction, and the reverse movement is a movement opposite to the current switch valve command movement direction.

[0011] In the above technical solution, the set deviation includes adjustment deviation, balance deviation and fault deviation;

[0012] When the maximum stroke deviation is greater than the adjustment deviation, it means that the stroke of the relay in the current movement direction exceeds the limit and needs to be switched to the reverse movement;

[0013] When the maximum stroke deviation is less than the balance deviation, it means that after the servomotor has gone through reverse motion, the synchronization requirements of all servomotors have been met and the reverse motion needs to be exited;

[0014] When the maximum stroke deviation is greater than the fault deviation, it indicates that a sticking fault has occurred in the cylindrical valve and the servomotor needs to stop operating.

[0015] In the above technical solution, the determination conditions of the cylindrical valve sticking failure also include:

[0016] The stroke of the servomotor's reverse movement exceeds the set threshold;

[0017] And / or, during a single valve opening or closing process, the number of times the servomotor performs reverse motion exceeds a preset number.

[0018] In the above technical solution, the controlling of the proportional valve according to the stroke deviation includes:

[0019] Perform proportional-integral calculation according to the stroke deviation to obtain synchronously regulated flow;

[0020] Determine the reference regulating flow rate according to the working condition of the cylinder valve;

[0021] The synchronous regulating flow and the reference regulating flow are superimposed to obtain the proportional valve regulating flow, and the opening of the proportional valve is controlled according to the proportional valve regulating flow.

[0022] In the above technical solution, during the valve opening process of the cylindrical valve, when the maximum stroke deviation is greater than the adjustment deviation, the relay switches to the opening reverse movement, closes the main pressure regulating valve, assigns the reference adjustment flow to the opening reverse current, and recalculates the proportional valve adjustment flow based on the re-assigned reference adjustment flow to control the opening of the proportional valve.

[0023] In the above technical solution, during the closing process of the cylindrical valve, when the maximum stroke deviation is greater than the adjustment deviation, the relay enters the closing reverse movement, the main pressure regulating valve is centered, and the reference adjustment flow is assigned as the closing reverse current. Based on the re-assigned reference adjustment flow, the proportional valve adjustment flow is recalculated to control the opening of the proportional valve.

[0024] In the above technical solution, during the switching process between forward motion and reverse motion, as long as it is determined that a cylindrical valve jamming failure occurs, the servomotor stops moving.

[0025] In the above technical solution, after the relay enters the reverse motion state, when the maximum stroke deviation is less than the balance deviation, the relay returns to the original motion state.

[0026] In the above technical solution, the moment when the cylindrical valve is stuck is determined, and the operation data is recorded in real time, and the operation data includes:

[0027] The driving current value of the proportional valve corresponding to each servomotor;

[0028] Real-time pressure value in each servomotor cavity;

[0029] The stroke value and stroke deviation of each servomotor, the stroke deviation of adjacent servomotors, the maximum and minimum strokes of all servomotors, and the real-time value of the maximum stroke deviation of the servomotor.

[0030] In the above technical solution, the expected stroke given value is the reference relay stroke;

[0031] The reference servomotor is the servomotor with the slowest travel speed or the servomotor with the travel speed closest to the average travel speed or the designated servomotor among the plurality of servomotors.

[0032] In summary, due to the adoption of the above technical features, the beneficial effects of the present invention are:

[0033] The method proposed in the present invention can monitor the data during the opening and closing process of the cylindrical valve of the hydropower unit in real time, accurately control and locate the fault when jamming occurs during the entire operation process, and collect fault data when jamming occurs, so as to facilitate timely inspection and processing by operation and maintenance personnel.

[0034] Specifically, the present invention can effectively perform synchronous control on the cylindrical valve, improve the stability of the cylindrical valve operation, reduce the failure rate, and improve the success rate of the start and stop of the unit, avoiding the occurrence of water machine accidents. It can also perform deviation adjustment during the opening and closing process of the cylindrical valve, and display the real-time fault information, so that the operation and maintenance personnel of the hydropower station can quickly determine the fault point and make corresponding disposal.

[0035] Additional aspects and advantages of the present invention will become apparent from the following description or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0037] Figure 1 It is a structural diagram of a common hydraulic system for controlling the opening and closing of a cylindrical valve;

[0038] Figure 2 It is a closed-loop control logic operation block diagram of a monitoring and control method for a cylindrical valve of a hydropower unit according to an embodiment of the present invention;

[0039] Figure 3 It is a schematic diagram of reverse motion input logic in a method for monitoring and controlling a cylindrical valve of a hydropower unit according to an embodiment of the present invention;

[0040] Figure 4 It is a flow chart of reverse motion control in a method for monitoring and controlling a cylindrical valve of a hydropower unit according to an embodiment of the present invention;

[0041] Figure 5 It is a flow chart of reverse movement control in a method for monitoring and controlling a cylindrical valve of a hydropower unit according to an embodiment of the present invention;

[0042] Figure 6 It is a schematic diagram of the reverse movement exit logic in the monitoring and control method of the cylindrical valve of a hydropower unit according to one embodiment of the present invention;

[0043] Figure 7 It is a logic diagram of a transfer stop state of a method for monitoring and controlling a cylindrical valve of a hydropower unit according to an embodiment of the present invention;

[0044] Figure 8 It is a schematic diagram of the alarm output logic of the cylindrical valve stuck fault in the monitoring and control method of the cylindrical valve of a hydropower unit according to one embodiment of the present invention;

[0045] Fig. 9 The present invention is a schematic diagram of the real-time display of a touch screen when a cylindrical valve fails to stick in a method for monitoring and controlling a cylindrical valve of a hydropower unit according to an embodiment of the present invention.

[0046] in, Figures 1 to 9 The corresponding relationship between the reference numerals and the component names is as follows:

[0047] 101, main pressure regulating valve; 103, on / off solenoid valve; 104, hydraulic control valve; 105, emergency shutdown solenoid valve;

[0048] 301, diverter;

[0049] 501, proportional valve; 504, hydraulically controlled one-way valve. DETAILED DESCRIPTION

[0050] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0051] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0052] Refer to the following Figures 1 to 9 A method for monitoring and controlling a cylindrical valve of a hydropower unit provided according to some embodiments of the present invention will be described.

[0053] Some embodiments of the present application provide a method for monitoring and controlling a cylindrical valve of a hydropower unit.

[0054] Figure 1 A common hydraulic system for controlling the opening and closing of a cylindrical valve is shown. The hydraulic system includes at least several servomotors, a main pressure regulating valve and a proportional valve. The servomotor is used to drive the cylindrical valve to open and close by hydraulic means, the main pressure regulating valve is used to control the pipeline for conveying pressurized oil to the servomotor, and the proportional valve is used to adjust the oil supply flow rate of each servomotor.

[0055] Specifically, the number of relays set is usually 6. Figure 1 Only three are shown, and their working principles are as follows:

[0056] When the hydraulic system operates normally in the hydropower unit, the emergency shutdown solenoid valve 105 works in the b valve position, outputs pressure oil to the control chamber of the hydraulic control valve 104, the hydraulic control valve 104 works in the cross position, and the control chamber of the main pressure regulating valve 101 is controlled by the switch solenoid valve 103.

[0057] Cylindrical valve opening control: When the on / off solenoid valve 103 is switched to valve position b, the main pressure regulating valve 101 controls the chamber to enter the pressure oil and switches to the open position. The output pressure oil enters the lower chamber of each servomotor through the diverter 301 to perform preliminary distribution of the pressure oil flow in the lower chamber. At the same time, the upper chamber of the servomotor is connected to the oil drain through the main pressure regulating valve 101, and the cylindrical valve is opened. During the opening process, the hydraulically controlled one-way valve 504 on the connecting pipeline of the lower chamber of the servomotor is unidirectionally conducted to ensure that the output pressure oil of the main pressure regulating valve 101 flows into the lower chamber of the servomotor in a unidirectional manner during the opening process. During the valve opening process, the system adjusts the oil supply flow rate by controlling the proportional valve 501 according to the stroke deviation between the six servomotors, and automatically completes the synchronous adjustment of the pressure oil supply flow rate in the lower chambers of the six servomotors during the valve opening process. It is understandable that Figure 1 The embodiments shown are only general illustrations known to those skilled in the art and do not limit the present disclosure. The method proposed in the present disclosure is applicable to any suitable hydraulic system. Figure 1 The method is introduced by taking the illustrated embodiment as an example.

[0058] The first embodiment of the present invention proposes a method for monitoring and controlling a cylindrical valve of a hydropower unit. The method includes the following steps S1-S4. It can be understood that the order of the steps S1-S4 in the present disclosure is only a schematic representation, and different steps can be performed simultaneously. Except for steps that are specifically specified to have a sequential association, those skilled in the art can flexibly adjust the order of the steps according to actual needs.

[0059] S1. Use a displacement sensor to collect the travel data of the relay in real time. It can be understood that the travel data represents the travel distance of a certain point on the relay from the set initial position at the current moment.

[0060] S2. Calculate the travel deviation between the actual travel of each servomotor and the expected travel given value.

[0061] Specifically, the expected stroke given value is the reference servomotor stroke; in some embodiments, the reference servomotor is the servomotor with the slowest travel speed or the servomotor closest to the average travel speed among several servomotors or any designated servomotor, which is not limited here.

[0062] S3. Control the proportional valve according to the stroke deviation, adjust the pressure oil supply flow rate in each servomotor cavity in real time, and realize synchronous control of each servomotor during the switching process of the cylindrical valve.

[0063] Through the above steps S1-S3, the stroke deviation of each servomotor and the reference servomotor is calculated in real time during the opening and closing process of the cylindrical valve, and a proportional integral operation (PI operation) is performed on the stroke deviation. The result of the PI operation is converted into a control signal for driving the proportional valve, and the servomotor is precisely adjusted in a closed loop. It should be noted that the specific operation method involved in the process of obtaining the control signal of the proportional valve through the PI operation according to the stroke deviation is well known to those skilled in the art, and is not the key point of this disclosure, and will not be repeated here.

[0064] The closed-loop control logic formed is as follows Figure 2 As shown, where Y set (k) is the stroke of the reference relay at time k, which is used as the expected stroke given value of all non-reference relays; Y FBK (k) is the non-reference servomotor travel at time k; Y is calculated by the operator set (k)-Y FBK (k) The obtained stroke deviation △Y is subjected to proportional plus integral PI operation to obtain the synchronous regulation flow. It can be understood that the synchronous regulation flow is only the flow control required to achieve synchronous regulation between the 6 relays. After combining with the reference regulation flow, the final proportional valve regulation flow is obtained, thereby achieving synchronous control of the 6 relays during the switching process; wherein, the reference regulation flow is automatically assigned to the corresponding reference control signal value according to the working condition of the cylindrical valve, that is to say, the reference regulation flow is a given value under different working conditions.

[0065] S4. During the opening or closing process of the cylindrical valve, the maximum stroke deviation of the servomotor is obtained in real time, and the maximum stroke deviation is compared with the set deviation, so that the servomotor switches between forward motion and reverse motion, and the cylindrical valve jamming failure is determined; wherein the forward motion is a motion that is consistent with the current switch valve command motion direction, and the reverse motion is a motion that is opposite to the current switch valve command motion direction.

[0066] In some embodiments, the above steps S1-S4 can all be completed by the PLC controller of the cylindrical valve control cabinet. The cylindrical valve servomotor synchronization judgment function is implemented by the cylindrical valve reverse movement and card issuance judgment subroutine. During the process of opening and closing the cylindrical valve, the servomotor automatically switches to the valve opening reverse movement, valve closing reverse movement or stop state due to the maximum stroke of the servomotor exceeding the tolerance. This automatic conversion of the cylindrical valve from normal working conditions to abnormal working conditions is implemented based on the servomotor synchronization judgment function subroutine. During the process of opening and closing the valve, the subroutine monitors the maximum stroke deviation of the servomotor in real time, and compares it with the set deviation to determine whether it is necessary to switch the working condition (switch the motion state) and whether it is necessary to shut down.

[0067] Specifically, the setting deviation includes adjustment deviation, balance deviation and fault deviation;

[0068] When the maximum stroke deviation is greater than the adjustment deviation, it means that the stroke of the relay in the current movement direction exceeds the limit and needs to be switched to the reverse movement;

[0069] When the maximum stroke deviation is less than the balance deviation, it means that after the servomotor has gone through reverse motion, the synchronization requirements of all servomotors have been met and the reverse motion needs to be exited;

[0070] When the maximum stroke deviation is greater than the fault deviation, it indicates that a sticking fault has occurred in the cylindrical valve and the servomotor needs to stop operating.

[0071] It is understandable that the adjustment deviation, balance deviation and fault deviation are all customized external settings and should be set according to the actual working conditions.

[0072] like Figure 3 As shown, the maximum stroke deviation during the valve opening process or the valve closing process exceeds the adjustment deviation, and a "reverse motion input command" is generated to cause the relay to switch to the opening reverse motion or the closing reverse motion; in order to reduce misjudgment, it should be ensured that at least the valve opening or closing operation has not been completed, and the data stability of the maximum stroke deviation needs to be ensured, and the data pointer situation when the PLC is started for the first time should be excluded.

[0073] According to the difference between the valve opening process and the valve closing process, the reverse motion is divided into opening reverse motion and closing reverse motion, and their control logics are different.

[0074] During the valve opening process of the cylindrical valve, when the maximum stroke deviation is greater than the adjustment deviation, the relay switches to the opening reverse movement, closes the main pressure regulating valve, assigns the reference adjustment flow to the opening reverse current, and recalculates the proportional valve adjustment flow based on the re-assigned reference adjustment flow to control the opening of the proportional valve.

[0075] Specifically, Figure 4 As shown, when the "reverse movement input command" is true and the "reverse movement exit command" is not established, the cylindrical valve working condition is transferred from the valve opening process to the open reverse movement. When the cylindrical valve is transferred to the open reverse movement during the valve opening process, the main pressure regulating valve is closed, the hydraulic control one-way valve is opened, and the reference regulating flow is assigned to the open reverse current (biased closed, less than 12mA, that is, under the control of the open reverse current, the relay will slowly move the cylindrical valve to the closed state). At the same time, the relay stroke deviation PID automatic adjustment synchronously adjusts the flow according to steps S1-S3, and finally the proportional valve regulating flow is obtained in combination with the reference regulating flow. Synchronously execute the cylindrical valve reverse movement and card issuance judgment subroutines, monitor the "reverse movement exit command" according to the real-time deviation of the maximum stroke deviation of the relay, and automatically return to the valve opening process or turn to the stop state according to the instructions of the "reverse movement exit command".

[0076] During the closing process of the cylindrical valve, when the maximum stroke deviation is greater than the adjustment deviation, the relay switches to the closing reverse movement, the main pressure regulating valve is centered, the reference adjustment flow is assigned as the closing reverse current, and the proportional valve adjustment flow is recalculated based on the re-assigned reference adjustment flow to control the opening of the proportional valve.

[0077] Specifically, Figure 5 As shown, when the "reverse movement input command" is true and the "reverse movement exit command" is not established, the cylindrical valve working condition changes from the closing process to the closing reverse movement. When the cylindrical valve changes from the closing process to the closing reverse movement, the main pressure regulating valve is centered, the hydraulically controlled one-way valve is locked, and the reference regulating flow of the proportional valve is assigned to the closing reverse current (biased open, greater than 12mA, that is, under the control of the closing reverse current, the relay will slowly move the cylindrical valve to the open state). At the same time, the relay stroke deviation PID automatic adjustment synchronous regulating flow is performed according to steps S1-S3, and finally the proportional valve regulating flow is obtained in combination with the reference regulating flow. The cylindrical valve reverse movement and card issuance judgment subroutines are executed synchronously, and the "reverse movement exit command" is monitored according to the real-time deviation of the maximum stroke deviation of the relay. According to the instructions of the "reverse movement exit command", it automatically returns to the valve closing process or turns to the stop state.

[0078] After the servomotor enters the reverse motion state, when the maximum stroke deviation is less than the balance deviation, the servomotor returns to the original motion state. Specifically, after the reverse motion of opening or closing, the factors causing the synchronization failure of the six servomotors may have been eliminated. At the same time, according to the regulation of the synchronous flow rate, the maximum stroke deviation will gradually decrease. When it is less than the balance deviation, it indicates that the synchronization of the servomotor meets the requirements, and the reverse motion state can be exited, returning to the original valve opening process or valve closing process. At this time, a "reverse motion exit command" is generated to terminate the control of the reverse motion.

[0079] In some embodiments, Figure 6 As shown, in order to ensure that during the switching process between forward and reverse motion, the servomotor stops as long as the cylindrical valve is determined to be stuck, the condition for generating the "reverse motion exit command" (valid) should include the condition of the stop state or the cylindrical valve stuck fault, in addition to the maximum stroke deviation being less than the balance deviation.

[0080] Figure 7 The judgment logic of the cylindrical valve card-issuing failure is shown. When any of the following conditions is met, the system is judged to have a cylindrical valve card-issuing failure and a "reverse or card-issuing stop command" is issued:

[0081] The stroke of the servomotor's reverse movement exceeds the set threshold;

[0082] During a single valve opening or closing process, the servomotor performs reverse motion more than the preset number of times;

[0083] The maximum travel deviation of the relay is greater than the fault deviation. In order to avoid misjudgment caused by data distortion, relevant criteria for duration exceeding the preset time can be added.

[0084] exist Figure 7 In the illustrated embodiment, the set threshold value of the stroke of the servomotor's reverse movement is 100 mm, and the preset number of times is 3 times. It is understandable that the above parameters can be adjusted according to actual conditions.

[0085] Figure 8 It is also illustrated in the figure that in actual application, the reset condition of the cylindrical valve sticking fault is that any one of the "comprehensive valve opening command", "comprehensive valve closing command", "HMI fault reset command" and "DI fault reset command" is true.

[0086] In some embodiments, when the "barrel valve stuck fault" is reported, the program automatically records the following operating data and displays the recording screen at the moment of the barrel valve stuck fault:

[0087] The driving current value of the proportional valve corresponding to each servomotor;

[0088] Real-time pressure values ​​in the upper and lower chambers of each servomotor;

[0089] The stroke value and stroke deviation of each servomotor, the stroke deviation of adjacent servomotors, the maximum and minimum strokes of all servomotors, the real-time value of the maximum stroke deviation of the servomotor, and the current reference servomotor number.

[0090] In a specific embodiment, the display interface is as follows: Fig. 9 As shown, the "Card Issuance Record Data Clear" button at the bottom of the screen can clear the record data after login authorization.

[0091] In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0092] Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for monitoring and controlling a cylindrical valve of a hydroelectric unit, wherein the cylindrical valve is controlled to be opened and closed by a hydraulic system, wherein the hydraulic system comprises at least a plurality of servomotors, a main pressure regulating valve and a proportional valve, wherein the servomotor is used to drive the cylindrical valve to be opened and closed by hydraulic means, the main pressure regulating valve is used to control a pipeline for conveying pressure oil to the servomotor, and the proportional valve is used to adjust the oil supply flow of each servomotor; characterized in that: The method comprises: Use displacement sensors to collect the travel data of the relay in real time; Calculate the travel deviation between the actual travel of each servomotor and the given value of the expected travel; The proportional valve is controlled according to the stroke deviation, and the pressure oil supply flow rate in each servomotor cavity is adjusted in real time to achieve synchronous control of each servomotor during the opening and closing process of the cylindrical valve; During the opening or closing process of the cylindrical valve, the maximum stroke deviation of the relay is obtained in real time, and the maximum stroke deviation is compared with the set deviation, so that the relay is switched between forward movement and reverse movement, and the cylindrical valve sticking failure is determined; wherein the forward movement is a movement consistent with the current switch valve command movement direction, and the reverse movement is a movement opposite to the current switch valve command movement direction.

2. The method for monitoring and controlling the cylindrical valve of a hydroelectric unit according to claim 1, characterized in that: The setting deviation includes adjustment deviation, balance deviation and fault deviation; When the maximum stroke deviation is greater than the adjustment deviation, it means that the stroke of the relay in the current movement direction exceeds the limit and needs to be switched to the reverse movement; When the maximum stroke deviation is less than the balance deviation, it means that after the servomotor has gone through reverse motion, the synchronization requirements of all servomotors have been met and the reverse motion needs to be exited; When the maximum stroke deviation is greater than the fault deviation, it indicates that a sticking fault has occurred in the cylindrical valve and the servomotor needs to stop operating.

3. The method for monitoring and controlling the cylindrical valve of a hydroelectric unit according to claim 2 is characterized in that: The determination conditions of the cylindrical valve sticking failure also include: The stroke of the servomotor's reverse movement exceeds the set threshold; And / or, during a single valve opening or closing process, the number of times the servomotor performs reverse motion exceeds a preset number.

4. The method for monitoring and controlling the cylindrical valve of a hydroelectric generator set according to claim 2, characterized in that: The controlling of the proportional valve according to the stroke deviation comprises: Perform proportional-integral calculation according to the stroke deviation to obtain synchronously regulated flow; Determine the reference regulating flow rate according to the working condition of the cylinder valve; The synchronous regulating flow and the reference regulating flow are superimposed to obtain the proportional valve regulating flow, and the opening of the proportional valve is controlled according to the proportional valve regulating flow.

5. The method for monitoring and controlling the cylindrical valve of a hydroelectric generator set according to claim 4 is characterized in that: During the valve opening process of the cylindrical valve, when the maximum stroke deviation is greater than the adjustment deviation, the relay switches to the opening reverse movement, closes the main pressure regulating valve, assigns the reference adjustment flow to the opening reverse current, and recalculates the proportional valve adjustment flow based on the re-assigned reference adjustment flow to control the opening of the proportional valve.

6. The method for monitoring and controlling the cylindrical valve of a hydroelectric generator set according to claim 4, characterized in that: During the closing process of the cylindrical valve, when the maximum stroke deviation is greater than the adjustment deviation, the relay switches to the closing reverse movement, the main pressure regulating valve is centered, the reference adjustment flow is assigned as the closing reverse current, and the proportional valve adjustment flow is recalculated based on the re-assigned reference adjustment flow to control the opening of the proportional valve.

7. The method for monitoring and controlling the cylindrical valve of a hydroelectric generator set according to claim 2, characterized in that: During the switching process between forward motion and reverse motion, the servomotor stops moving as long as it is determined that a cylindrical valve jam has occurred.

8. The method for monitoring and controlling the cylindrical valve of a hydroelectric generator set according to claim 2, characterized in that: After the relay enters the reverse motion state, when the maximum stroke deviation is less than the balance deviation, the relay returns to the original motion state.

9. The method for monitoring and controlling the cylindrical valve of a hydroelectric generator set according to claim 8, characterized in that: Determine the moment when the cylindrical valve is stuck and record the operation data in real time. The operation data includes: The driving current value of the proportional valve corresponding to each servomotor; Real-time pressure value in each servomotor cavity; The stroke value and stroke deviation of each servomotor, the stroke deviation of adjacent servomotors, the maximum and minimum strokes of all servomotors, and the real-time value of the maximum stroke deviation of the servomotor.

10. The method for monitoring and controlling the cylindrical valve of a hydroelectric generator set according to claim 1, characterized in that: The expected stroke given value is the reference servomotor stroke; The reference servomotor is the servomotor with the slowest travel speed or the servomotor with the travel speed closest to the average travel speed or the designated servomotor among the plurality of servomotors.

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