Stroke positioning control method and system for cylindrical valve servomotor of water turbine

Abstract

The invention provides a hydraulic turbine cylindrical valve servomotor stroke positioning control method and system. The method comprises the steps that real-time stroke data of all servomotors are obtained; the plurality of servomotors comprise a reference servomotor and a non-reference servomotor; the positioning stroke of the servomotor is determined, and the difference value between the positioning stroke of the servomotor and the real-time stroke of the reference servomotor is calculated to obtain the positioning stroke deviation; when it is judged that the absolute value of the positioning stroke deviation is larger than a positioning adjusting threshold value, a positioning adjusting mode is started to adjust and control the stroke of the servomotor, and the real-time stroke of the reference servomotor approaches the positioning stroke of the servomotor; after the absolute value of the positioning stroke deviation is smaller than or equal to a positioning balance threshold value, the positioning adjustment mode is quitted, and the servomotor is turned to a stop state; the system comprises a positioning control loop and a synchronization control loop. According to the invention, the special requirement that the stroke of the cylindrical valve servomotor needs to be reliably positioned at a certain middle stroke of non-fully-open and fully-closed positions during the debugging or maintenance period of a power station worker can be met.

Description

Technical Field

[0001] The invention relates to the technical field of water turbine cylinder valve control, and in particular to a water turbine cylinder valve servomotor stroke positioning control method and system. Background Art

[0002] Cylinder valves play a vital role in the safe and efficient operation of hydropower stations. When the unit is running, the cylinder valve is in the fully open position to provide water for power generation to the turbine. After the unit is shut down, the cylinder valve is in the fully closed position to ensure the safety of the unit in the shutdown state. In the event of an emergency in the turbine and its piping system, the cylinder valve can be quickly closed to prevent the water flow from damaging the system. When the turbine or related equipment needs to be repaired or maintained, the water flow also needs to be closed through the cylinder valve so that the power station staff can operate and repair safely. Improving the maintenance efficiency of turbine cylinder valves can timely discover and solve potential problems and prevent small faults from turning into major faults, thereby minimizing equipment downtime, reducing the frequency and cost of emergency repairs, extending the service life of cylinder valves and related equipment, keeping cylinder valves operating in optimal conditions, and avoiding shortening the equipment life cycle due to long-term accumulated problems.

[0003] In order to achieve a more comprehensive and systematic maintenance of the turbine cylinder valve, in addition to fully opening or closing the cylinder valve, it may also be necessary to position the cylinder valve servomotor at a specific stroke in order to carry out inspection and operation of the corresponding part. However, in the current existing technology, there are few cylinder valve control methods or systems with the function of positioning and controlling the cylinder valve servomotor at any stroke, and it is difficult to ensure the reliable positioning of the servomotor at the specified stroke position, which is not only easy to cause damage to the system and pose a safety hazard, but also brings great inconvenience to the inspection and maintenance work of the power station staff, making it difficult to complete the comprehensive maintenance of the turbine cylinder valve. 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, a first aspect of the present invention provides a method for controlling the stroke positioning of a hydraulic turbine cylindrical valve servomotor.

[0006] A second aspect of the present invention provides a travel positioning control system for a hydraulic turbine cylindrical valve servomotor.

[0007] The present invention provides a method for controlling the stroke positioning of a hydraulic turbine cylinder valve servomotor, which controls the servomotor to drive the opening and closing of the cylinder valve through an electro-hydraulic converter, wherein the electro-hydraulic converter receives a flow control signal, and is characterized in that it includes:

[0008] Acquire real-time travel data of all relays; the plurality of relays include reference relays and non-reference relays;

[0009] Determine the positioning stroke of the relay, calculate the difference between the positioning stroke of the relay and the real-time stroke of the reference relay to obtain the positioning stroke deviation;

[0010] When it is determined that the absolute value of the positioning stroke deviation is greater than the positioning adjustment threshold, the positioning adjustment mode is started to adjust the stroke of the servomotor so that the real-time stroke of the reference servomotor approaches the positioning stroke of the servomotor; and after the absolute value of the positioning stroke deviation is less than or equal to the positioning balance threshold, the positioning adjustment mode is exited and the servomotor is turned to a stopped state;

[0011] Among them, in the positioning adjustment mode, a positive positioning control signal or a reverse positioning control signal is generated according to the positive or negative positioning stroke deviation, and the forward positioning control signal is used to control the relay to continue moving in the same direction as the current movement direction, and the reverse positioning control signal is used to control the relay to continue moving in the direction opposite to the current movement direction; when exiting the positioning adjustment mode, a neutral positioning control signal is generated, and the neutral positioning control signal is used to control the relay to enter a stop state.

[0012] The method for controlling the stroke positioning of a hydraulic turbine cylindrical valve servomotor according to the above technical solution of the present invention may also have the following additional technical features:

[0013] In the above technical solution, the flow control signal at least includes a positioning control signal;

[0014] The starting positioning adjustment mode is used to adjust the stroke of the servo, including:

[0015] When the positioning stroke deviation is greater than the positive value of the positioning adjustment threshold, the positioning control signal is assigned as a positive positioning control signal to control the electro-hydraulic converter so that the cylindrical valve keeps performing an opening or closing movement;

[0016] When the positioning stroke deviation is less than the negative value of the positioning adjustment threshold, the positioning control signal is assigned as a reverse positioning control signal to control the electro-hydraulic converter to make the cylindrical valve perform a movement opposite to the current opening and closing process;

[0017] During the regulation process, the positioning stroke deviation is updated in real time, and after the absolute value of the positioning stroke deviation is less than or equal to the positioning balance threshold, the positioning control signal is assigned a median positioning control signal to control the electro-hydraulic converter to turn the cylindrical valve into a stopped state.

[0018] In the above technical solution, the forward positioning control signal, the reverse positioning control signal and the middle positioning control signal are all preset constant values.

[0019] The above technical solution also includes:

[0020] Get the maximum and minimum values ​​of all relays in real-time travel and calculate the maximum travel deviation;

[0021] When the maximum stroke deviation is greater than the synchronous stop threshold, the positioning control signal is assigned a value as a median positioning control signal.

[0022] The above technical solution also includes:

[0023] When the maximum stroke deviation is less than the synchronous stop-and-go threshold, the system returns to the determination of the positioning stroke deviation to determine whether to start the positioning adjustment mode.

[0024] In the above technical solution, the flow control signal also includes a synchronization control signal, and the positioning control signal and the synchronization control signal are added to generate the flow control signal;

[0025] The control method further comprises:

[0026] Calculate the difference between the real-time travel of each non-reference servomotor and the real-time travel of the reference servomotor as the synchronization deviation;

[0027] A PI controller is used to generate a synchronization control signal according to the synchronization deviation, and the synchronization control signal is used to control the non-reference servomotor to maintain synchronization with the reference servomotor.

[0028] In the above technical solution, the electro-hydraulic converter controls the magnitude of the flow rate output to the servomotor according to the flow control signal, and the flow control signal is proportional to the flow rate output to the servomotor;

[0029] When the flow control signal is positive, the electro-hydraulic converter controls the oil filling of the lower chamber of the servomotor;

[0030] When the flow control signal is negative, the electro-hydraulic converter controls the lower chamber of the servomotor to drain oil.

[0031] In the above technical solution, amplifying the forward positioning control signal or the reverse positioning control signal can speed up the adjustment speed of the cylindrical valve;

[0032] The hysteresis value between the positioning adjustment threshold and the positioning balance threshold is related to the accuracy of positioning control. The smaller the hysteresis value, the higher the accuracy of positioning control.

[0033] In the above technical solution, a displacement sensor is used to monitor the real-time travel data of each relay.

[0034] A hydraulic turbine cylinder valve servomotor stroke positioning control system provided by the present invention is applied to a hydraulic turbine cylinder valve servomotor stroke positioning control method as described in any of the above technical solutions, and the system comprises:

[0035] A positioning control loop, taking the positioning stroke set by the relay as the expected positioning stroke of all relay strokes, and positioning all relays at any intermediate stroke at a set rate; the positioning control loop is used to generate a positioning control signal;

[0036] Synchronous control loop, the stroke of all non-reference relays is based on the stroke of the reference relay as the expected stroke, the stroke deviation between the reference relay and each non-reference relay is input into the PI controller corresponding to each non-reference relay, and the synchronous control signal of all non-reference relays is obtained;

[0037] Control the electro-hydraulic converter corresponding to each servomotor according to the positioning control signal and the synchronization control signal, thereby changing the stroke of the servomotor accordingly;

[0038] The reference servomotor is controlled by a positioning control loop, and the non-reference servomotor is controlled by a positioning control loop and a synchronization control loop.

[0039] In summary, due to the adoption of the above technical features, the beneficial effects of the present invention are:

[0040] The present invention adds a cylinder valve servomotor stroke positioning function to the cylinder valve control system, improves the maintenance efficiency of the turbine cylinder valve, and provides strong support for the efficient maintenance of the turbine cylinder valve. During the maintenance of the cylinder valve control system, the control method can realize the accurate positioning of the turbine cylinder valve servomotor at any intermediate stroke between the fully closed and fully open positions, which is convenient for the special needs of power station staff for debugging, troubleshooting and maintenance.

[0041] Specifically, the positioning control of the present invention adopts fixed value adjustment, which is simple and effective. When the positioning rate requirement is not high, it is entirely possible to ensure sufficient stroke positioning accuracy by setting appropriate fixed value opening, closing and mid-position flow control signals, thereby providing great convenience for power station staff in carrying out debugging, troubleshooting and maintenance work.

[0042] The positioning control loops of all servomotors of the cylindrical valve adopt set rate control, which avoids the control pull and repeated adjustment caused by the simultaneous action of the dual PI control of the positioning control loop and the synchronous control loop on the non-reference servomotor if the positioning control loop also adopts independent PI control.

[0043] 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

[0044] 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:

[0045] Figure 1The present invention is a logic block diagram of a method for controlling the travel and positioning of a hydraulic turbine cylindrical valve servomotor according to an embodiment of the present invention. DETAILED DESCRIPTION

[0046] 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.

[0047] 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.

[0048] Refer to the following Figure 1 The following describes a method and system for controlling the stroke positioning of a hydraulic turbine cylinder valve servomotor according to some embodiments of the present invention.

[0049] Some embodiments of the present application provide a method for controlling the stroke positioning of a hydraulic turbine cylindrical valve servomotor.

[0050] like Figure 1 As shown, the first embodiment of the present invention proposes a method for controlling the stroke positioning of a hydraulic turbine cylindrical valve servomotor, wherein the servomotor drives the opening and closing of the cylindrical valve through an electro-hydraulic converter, and the electro-hydraulic converter receives a flow control signal. It can be understood that the electro-hydraulic converter is a part of the existing cylindrical valve hydraulic control system, and the electro-hydraulic converter refers to a device that converts a signal in the form of voltage or current into a liquid pressure or flow signal. That is to say, by adjusting the flow control signal received by the electro-hydraulic converter, the hydraulic control system can be controlled to inject or drain oil into the lower chamber of each servomotor, thereby controlling the stroke of the servomotor and locking the opening and closing position of the cylindrical valve. Specifically, the electro-hydraulic converter controls the size of the flow output to the servomotor according to the flow control signal, and the flow control signal is proportional to the flow output to the servomotor; when the flow control signal is positive, the electro-hydraulic converter controls the injection of oil into the lower chamber of the servomotor; when the flow control signal is negative, the electro-hydraulic converter controls the drainage of oil from the lower chamber of the servomotor.

[0051] The control method referred to in the present disclosure at least includes the following steps S1-S3. It should be noted that, in general, the number of servomotors used to control the cylindrical valve is 6, and each servomotor is equipped with a corresponding electro-hydraulic converter and PI controller, and the present disclosure is explained on this basis.

[0052] S1. Acquire real-time travel data of all servomotors; the plurality of servomotors include reference servomotors and non-reference servomotors.

[0053] In some embodiments, the real-time travel data of the relay can be obtained by setting a displacement sensor on the relay. Of course, other similar sensors or acquisition devices can also be used to obtain real-time travel data. The real-time travel data refers to the distance that any reference point on the relay moves relative to the specified initial position.

[0054] Among them, among the 6 relays, one is selected as the reference relay, and the rest are non-reference relays. It can be understood that the selection of the reference relay can be randomly selected or selected according to certain rules, such as the slowest travel speed, the travel speed closest to the average, etc. In the present disclosure, among the relays No. 1 to No. 6, relay No. 1 is selected as the reference relay, and the real-time travel data of relays No. 1 to No. 6 is Y fbk1 ~Y fbk6 , where Y fbk1 It is the real-time travel of the reference relay.

[0055] S2. Determine the positioning stroke of the servomotor, and calculate the difference between the positioning stroke of the servomotor and the real-time stroke of the reference servomotor to obtain the positioning stroke deviation.

[0056] Specifically, the positioning stroke of the relay is the target stroke when the relay moves to the specified position, which is mainly used as reference value data and is expressed by Y set express.

[0057] Then the positioning stroke deviation ΔY 基准 =Y set -Y fbk1 ; It is understandable that the positioning stroke deviation may be positive or negative.

[0058] S3. When it is determined that the absolute value of the positioning stroke deviation is greater than the positioning adjustment threshold, the positioning adjustment mode is started to regulate the stroke of the servomotor so that the real-time stroke of the reference servomotor approaches the positioning stroke of the servomotor; and after the absolute value of the positioning stroke deviation is less than or equal to the positioning balance threshold, the positioning adjustment mode is exited and the servomotor is turned to a stopped state; the positioning adjustment threshold is mainly used as an entry condition for entering the positioning adjustment mode; the positioning balance threshold is used to determine whether the current position of the servomotor meets the target positioning requirement; it can be understood that the positioning adjustment threshold is greater than the positioning balance threshold.

[0059] Among them, in the positioning adjustment mode, a positive positioning control signal or a reverse positioning control signal is generated according to the positive or negative positioning stroke deviation, and the forward positioning control signal is used to control the relay to continue to move in the same direction as the current movement direction, and the reverse positioning control signal is used to control the relay to continue to move in the opposite direction to the current movement direction; when exiting the positioning adjustment mode, a median positioning control signal is generated, and the median positioning control signal is used to control the relay to enter a stop state. In other words, if the positioning stroke deviation is positive, it means that the relay has not reached the target position in the current direction of travel and can continue to move forward; if the positioning stroke deviation is negative, it means that the relay has exceeded the target position in the current direction of travel and needs to turn back. In general, the forward positioning control signal can be set to control the cylindrical valve to lift up and move in the opening direction; the reverse positioning control signal can be set to control the cylindrical valve to fall and move in the closing direction; this is used as an example for explanation in the present disclosure, and of course the opposite setting can also be adopted.

[0060] In some embodiments, the flow control signal includes at least a positioning control signal;

[0061] The starting positioning adjustment mode is used to adjust the stroke of the servo, including:

[0062] When the positioning stroke deviation ΔY 基准 When it is positive and greater than the positive value of the positioning adjustment threshold, the positioning control signal is assigned a positive positioning control signal to control the electro-hydraulic converter to inject oil into the lower chamber of the servomotor, so as to achieve synchronous lifting of servomotors No. 1 to No. 6, so that the cylindrical valve keeps executing the opening movement;

[0063] When the positioning stroke deviation ΔY 基准 When it is negative and less than the negative value of the positioning adjustment threshold, the positioning control signal is assigned to the reverse positioning control signal, and the electro-hydraulic converter is controlled to discharge the oil from the lower chamber of the servomotor, so as to achieve the synchronous falling of servomotors No. 1 to No. 6 and make the cylindrical valve perform the closing movement;

[0064] The positioning stroke deviation is updated in real time during the regulation process, and after the absolute value of the positioning stroke deviation is less than or equal to the positioning balance threshold, the positioning control signal is assigned to the median positioning control signal. At this time, the oil circuit from the electro-hydraulic converter to the lower chamber of the relay is cut off, and the cylindrical valve is transferred from the original lifting process or the falling process to the stop state. All relays maintain the current stroke unchanged and exit the relay positioning adjustment mode.

[0065] In some embodiments, the forward positioning control signal, the reverse positioning control signal and the middle positioning control signal are all preset constant values, that is, through the fixed value adjustment method, the cylindrical valve reaches the positioning stroke at a relatively constant rate.

[0066] Among them, amplifying the forward positioning control signal or the reverse positioning control signal can speed up the adjustment speed of the cylindrical valve; the hysteresis value between the positioning adjustment threshold and the positioning balance threshold is related to the accuracy of the positioning control. The smaller the hysteresis value, the higher the accuracy of the positioning control. Based on the above properties, in the process of stroke positioning control, it is necessary to set appropriate "forward positioning control signal" and "reverse positioning control signal" to match the "positioning adjustment threshold" for starting positioning adjustment and the "positioning balance threshold" for exiting positioning adjustment. If the opening and closing direction adjustment speed is too slow, the "forward positioning control signal" and "reverse positioning control signal" can be appropriately amplified step by step, and the "positioning balance deviation" should be appropriately amplified accordingly to avoid over-adjustment; for example, in the relay positioning stroke Y set When the reference relay stroke approaches Y set When the cylindrical valve switches frequently between the lifting and falling processes, the hysteresis value between the "positioning adjustment threshold" and the "positioning balance threshold" can be appropriately enlarged.

[0067] In some embodiments, in order to prevent the servomotors from losing synchronization and causing system failure, steps S4 and S5 are further provided. It should be noted that steps S4-S5 are executed synchronously with steps S2-S3.

[0068] S4. Get the maximum value Y in the real-time travel of all relays fbk_max and minimum value Y fbk_min , calculate the maximum travel deviation; specifically, maximum travel deviation = Y fbk_max -Y fbk_min .

[0069] S5. When the maximum stroke deviation is greater than the synchronous stop threshold, it indicates that each servomotor has a synchronization problem or a jamming failure, and the positioning control signal is assigned a mid-position positioning control signal, and the cylindrical valve stops moving unconditionally.

[0070] When the maximum stroke deviation is less than the synchronous stop-and-retreat threshold, the process returns to step S2-S3 to determine whether the positioning adjustment mode is started, that is, to determine whether the cylindrical valve needs to continue to be lifted or lowered.

[0071] In the above technical solution, the flow control signal also includes a synchronization control signal, and the positioning control signal and the synchronization control signal are added to generate the flow control signal;

[0072] In some embodiments, in order to achieve synchronous fine adjustment of the flow rate of the non-reference servomotor of the cylindrical valve, the control method further includes steps S6-S7. Similarly, steps S6-S7 are executed synchronously with steps S2-S3.

[0073] S6, calculating the difference between the real-time travel of each non-reference servomotor and the real-time travel of the reference servomotor as a synchronization deviation;

[0074] S7. Using a PI controller to generate a synchronization control signal according to the synchronization deviation, wherein the synchronization control signal is used to control the non-reference servomotor to maintain synchronization with the reference servomotor.

[0075] Specifically, no matter the cylindrical valve is in the lifting process, the falling process or the stopped state, although each servomotor is assigned an equivalent positioning control signal in the same direction according to S2~S3, due to the zero point difference of each electro-hydraulic converter, the difference in the pipeline layout of each servomotor, the air intake of individual pipelines and many other objective factors, the real-time stroke deviation between the non-reference servomotor and the reference servomotor will be caused, that is, the real-time stroke deviation between servomotor No. 2 and No. 1, servomotor No. 3 and No. 1, servomotor No. 4 and No. 1, servomotor No. 5 and No. 1, servomotor No. 6 and No. 1, respectively, is: ΔY 21 =Y fbk1 -Y fbk2 , ΔY 31 =Y fbk1 -Y fbk3 , ΔY 41 =Y fbk1 -Y fbk4 , ΔY 51 =Y fbk1 -Y fbk5 , ΔY 61 =Y fbk1 -Y fbk6 , and input ΔY21, ΔY31, ΔY41, ΔY51, and ΔY61 into their respective corresponding PI controllers, and then superimpose the synchronous control signal output by the corresponding PI controller of each servomotor on the positioning control signal and assign it to the flow control signal of the electro-hydraulic converter, ultimately achieving synchronous and precise flow regulation of the cylindrical valve servomotor in the entire process of stroke positioning control.

[0076] It should be noted that the PI controller refers to a proportional-integral operation controller, which is used to synchronously control all relays according to the stroke deviation. The specific proportional-integral operation algorithm is well known to those skilled in the art and will not be elaborated here.

[0077] Other embodiments of the present invention provide a turbine cylinder valve servomotor stroke positioning control system, which is applied to the turbine cylinder valve servomotor stroke positioning control method as described in any of the above embodiments, and the system includes a positioning control loop and a synchronization control loop.

[0078] In the positioning control loop, the positioning stroke set by the relay is used as the expected positioning stroke of all relay strokes, and all relays are positioned at any intermediate stroke at a set rate; the positioning control loop is used to generate a positioning control signal.

[0079] In the synchronous control loop, the stroke of all non-reference relays is based on the stroke of the reference relay as the expected stroke, and the stroke deviation between the reference relay and each non-reference relay is input into the PI controller corresponding to each non-reference relay to obtain the synchronous control signal of all non-reference relays.

[0080] The electro-hydraulic converter corresponding to each servomotor is controlled according to the positioning control signal and the synchronization control signal, thereby changing the stroke of the servomotor accordingly.

[0081] The reference servomotor is then controlled by the positioning control loop, and the non-reference servomotor is controlled by both the positioning control loop and the synchronization control loop.

[0082] In a specific embodiment, taking a large domestic power station as an engineering example, the turbine cylinder valve servomotor is in the maintenance positioning operation mode, and the positioning stroke is set in sequence from the fully closed position of the cylinder valve to: 100, 200, 300, 400, 500, 600, 700, 600, 500, 400, 300, 200, 100 mm. When the servomotor is continuously lifted and lowered, the steady-state stroke values ​​of servomotors No. 1 to 6 are recorded as shown in the following table.

[0083]

[0084] It can be seen from the table that the average stroke deviation and maximum synchronization deviation of the turbine cylinder valve in the positioning adjustment mode are no more than 1mm (1mm is about 0.072% of the full stroke of the relay), which can fully meet the relay positioning needs during cylinder valve commissioning, troubleshooting and maintenance.

[0085] 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.

[0086] 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 controlling the stroke positioning of a hydraulic turbine cylinder valve servomotor, wherein the servomotor drives the opening and closing of the cylinder valve through an electro-hydraulic converter, wherein the electro-hydraulic converter receives a flow control signal, and wherein: include: Acquire real-time travel data of all relays; the plurality of relays include reference relays and non-reference relays; Determine the positioning stroke of the relay, calculate the difference between the positioning stroke of the relay and the real-time stroke of the reference relay to obtain the positioning stroke deviation; When it is determined that the absolute value of the positioning stroke deviation is greater than the positioning adjustment threshold, the positioning adjustment mode is started to adjust the stroke of the servomotor so that the real-time stroke of the reference servomotor approaches the positioning stroke of the servomotor; and after the absolute value of the positioning stroke deviation is less than or equal to the positioning balance threshold, the positioning adjustment mode is exited and the servomotor is turned to a stopped state; Among them, in the positioning adjustment mode, a positive positioning control signal or a reverse positioning control signal is generated according to the positive or negative positioning stroke deviation, and the forward positioning control signal is used to control the relay to continue moving in the same direction as the current movement direction, and the reverse positioning control signal is used to control the relay to continue moving in the direction opposite to the current movement direction; when exiting the positioning adjustment mode, a neutral positioning control signal is generated, and the neutral positioning control signal is used to control the relay to enter a stop state.

2. The method for controlling the stroke positioning of a hydraulic turbine cylinder valve servomotor according to claim 1, characterized in that: The flow control signal at least includes a positioning control signal; The starting positioning adjustment mode is used to adjust the stroke of the servo, including: When the positioning stroke deviation is greater than the positive value of the positioning adjustment threshold, the positioning control signal is assigned as a positive positioning control signal to control the electro-hydraulic converter so that the cylindrical valve keeps performing an opening or closing movement; When the positioning stroke deviation is less than the negative value of the positioning adjustment threshold, the positioning control signal is assigned as a reverse positioning control signal to control the electro-hydraulic converter to make the cylindrical valve perform a movement opposite to the current opening and closing process; During the regulation process, the positioning stroke deviation is updated in real time, and after the absolute value of the positioning stroke deviation is less than or equal to the positioning balance threshold, the positioning control signal is assigned a median positioning control signal to control the electro-hydraulic converter to turn the cylindrical valve into a stopped state.

3. The method for controlling the stroke positioning of a hydraulic turbine cylinder valve servomotor according to claim 2, characterized in that: The forward positioning control signal, the reverse positioning control signal and the middle positioning control signal are all preset constant values.

4. The method for controlling the stroke positioning of a hydraulic turbine cylinder valve servomotor according to claim 2, characterized in that: Also includes: Get the maximum and minimum values ​​of all relays in real-time travel and calculate the maximum travel deviation; When the maximum stroke deviation is greater than the synchronous stop threshold, the positioning control signal is assigned a value as a median positioning control signal.

5. The method for controlling the stroke positioning of a hydraulic turbine cylinder valve servomotor according to claim 2, characterized in that: Also includes: When the maximum stroke deviation is less than the synchronous stop-and-retreat threshold, the judgment of the positioning stroke deviation is returned to determine whether to start the positioning adjustment mode.

6. The method for controlling the stroke positioning of a hydraulic turbine cylindrical valve servomotor according to claim 2, characterized in that: The flow control signal also includes a synchronization control signal, and the positioning control signal and the synchronization control signal are added to generate the flow control signal; The control method further comprises: Calculate the difference between the real-time travel of each non-reference servomotor and the real-time travel of the reference servomotor as the synchronization deviation; A PI controller is used to generate a synchronization control signal according to the synchronization deviation, and the synchronization control signal is used to control the non-reference servomotor to maintain synchronization with the reference servomotor.

7. The method for controlling the stroke positioning of a hydraulic turbine cylinder valve servomotor according to claim 1, characterized in that: The electro-hydraulic converter controls the magnitude of the flow rate output to the servomotor according to the flow rate control signal, and the flow rate control signal is proportional to the flow rate output to the servomotor; When the flow control signal is positive, the electro-hydraulic converter controls the oil filling of the lower chamber of the servomotor; When the flow control signal is negative, the electro-hydraulic converter controls the lower chamber of the servomotor to drain oil.

8. The method for controlling the stroke positioning of a hydraulic turbine cylinder valve servomotor according to claim 7, characterized in that: Amplifying the forward positioning control signal or the reverse positioning control signal can speed up the adjustment speed of the cylindrical valve; The hysteresis value between the positioning adjustment threshold and the positioning balance threshold is related to the accuracy of positioning control. The smaller the hysteresis value, the higher the accuracy of positioning control.

9. The method for controlling the stroke positioning of a hydraulic turbine cylinder valve servomotor according to claim 1, characterized in that: Displacement sensors are used to monitor the real-time travel data of each servomotor.

10. A hydraulic turbine cylinder valve servo travel positioning control system, characterized in that: The method for controlling the stroke positioning of a hydraulic turbine cylinder valve servomotor according to any one of claims 1 to 9, the system comprising: A positioning control loop, taking the positioning stroke set by the relay as the expected positioning stroke of all relay strokes, and positioning all relays at any intermediate stroke at a set rate; the positioning control loop is used to generate a positioning control signal; Synchronous control loop, the stroke of all non-reference relays is based on the stroke of the reference relay as the expected stroke, the stroke deviation between the reference relay and each non-reference relay is input into the PI controller corresponding to each non-reference relay, and the synchronous control signal of all non-reference relays is obtained; Control the electro-hydraulic converter corresponding to each servomotor according to the positioning control signal and the synchronization control signal, thereby changing the stroke of the servomotor accordingly; The reference servomotor is controlled by a positioning control loop, and the non-reference servomotor is controlled by a positioning control loop and a synchronization control loop.

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