Self-tuning method for intelligent valve positioner of nuclear power plant

Abstract

The invention relates to a self-tuning method for an intelligent valve positioner of a nuclear power plant. The method comprises the following steps: safe speed tuning; the safety speed setting comprises the steps that the current position of a valve is set to be at the initial position, and air inlet is controlled through a first set control quantity; the valve is controlled to move to the target valve position, the current valve position speed and the current valve position at the moment are determined to be the first valve position speed and the first valve position respectively, and exhaust is controlled through the second set control quantity; the current speed of the valve position is controlled to be reduced to zero, and the current valve position at the moment is determined as a second valve position; whether the absolute value of the difference value between the second valve position and the first valve position is larger than a first preset difference value or not is judged; and if not, the first valve position speed is determined to be the safety speed for setting the safety speed, so that the situation of valve position overshoot is reduced, and the valve position control precision can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of valve positioners, and in particular to a self-tuning method for an intelligent valve positioner in a nuclear power plant. Background Art

[0002] In nuclear power plants, smart valve positioners are usually required to adjust the valve opening. At present, smart valve positioners are mainly divided into four different types, which are composed of piezoelectric valves, IP conversion units of nozzle baffles, and pneumatic amplifiers of slide valve structures and membrane valve structures. Among them, the positioners based on piezoelectric valves and slide valve structures are easy to realize the on and off of the gas circuit, so it is relatively easy for this type of positioner to control the valve position. Although the positioners based on nozzle baffles and membrane valve structures cannot simply realize the on and off of the gas circuit, the nozzle baffles and membrane valve structures have lower requirements for the gas source, such as there are no great requirements for water, oil, and particles in the gas source. Therefore, in smart valve positioners, nozzle baffles and membrane valve structures are widely used.

[0003] At the same time, it is precisely because the positioner based on the nozzle baffle and membrane valve structure cannot simply realize the opening and closing of the gas path, which increases the difficulty of valve position control. In order to improve the adaptability of this type of positioner under different conditions, the self-tuning method based on this structure is of great significance.

[0004] Speed ​​setting is one of the important functions in the self-tuning method. If the speed is too high, it will easily overshoot, resulting in an increase in overshoot. If the speed is too low, it will easily undershoot, resulting in an increase in adjustment time. Different positioners usually have different self-tuning methods. At present, most positioners based on nozzle baffles and membrane valve structures usually only set the maximum speed used to shorten the time required to reach the preset valve position and the minimum speed used for fine-tuning, but do not define and set the safe speed. In the process of switching from hysteresis (Bang-Bang) control to proportional-integral-differential (PID) control, if the speed during switching cannot be reduced to the safe speed, the valve position will overshoot when the speed decelerates to zero, resulting in reduced valve position control accuracy. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a self-tuning method for an intelligent valve positioner in a nuclear power plant, so as to achieve safe speed tuning to reduce valve position overshoot, thereby improving valve position control accuracy.

[0006] The technical solution adopted by the present invention to solve the technical problem is: providing a self-tuning method for an intelligent valve positioner in a nuclear power plant, including: safe speed tuning;

[0007] The safety speed setting includes:

[0008] S101, setting the current position of the valve to an initial position, and controlling the air intake with a first set control amount;

[0009] S102, controlling the valve to move to a target valve position, determining that the current valve position speed and the current valve position at this moment are respectively the first valve position speed and the first valve position, and controlling the exhaust with a second set control amount;

[0010] S103, controlling the current speed of the valve position to decrease to zero, and determining the current position of the valve at this moment to be the second valve position;

[0011] S104, determining whether the absolute value of the difference between the second valve position and the first valve position is greater than a first preset difference;

[0012] S105: If not, determine that the first valve position speed is a safe speed.

[0013] Preferably, after step S105, the safety speed setting further includes:

[0014] S106, when the Bang-Bang control ends, determining that the current position of the valve at this moment is the third valve position;

[0015] S107, when PID control starts, determining that the current position of the valve at this moment is the fourth valve position;

[0016] S108, determining whether the absolute value of the difference between the fourth valve position and the third valve position is greater than a second preset difference;

[0017] S109: If yes, reduce the value of the safety speed.

[0018] Preferably, after step S109, the safety speed setting further includes:

[0019] S110, if not, determining whether the absolute value of the difference between the fourth valve position and the third valve position is less than a third preset difference;

[0020] S111. When the absolute value of the difference between the fourth valve position and the third valve position is less than a third preset difference, increase the value of the safety speed.

[0021] Preferably, after step S104, the safety speed setting further includes:

[0022] If yes, then set the current position of the valve to return to the initial position, adjust the value of the control amount and update it to the first set control amount;

[0023] Repeat steps S102 to S105.

[0024] Preferably, the positioner self-tuning method further comprises: initial control quantity tuning of a large range of set points;

[0025] The initial control quantity setting of the large range set point includes:

[0026] S201, the control valve moves to the first preset valve position, the second preset valve position and the third preset valve position in sequence according to the upstroke path, and determines the corresponding first control amount, the second control amount and the third control amount;

[0027] S202, fitting a first straight line on a first coordinate axis according to the first preset valve position, the first control amount, the second preset valve position, and the second control amount, and fitting a second straight line on the first coordinate axis according to the second preset valve position, the second control amount, the third preset valve position, and the third control amount, wherein the abscissa of the first coordinate axis is the valve position, and the ordinate is the control amount;

[0028] S203, determining whether the target valve position is less than the second preset valve position;

[0029] S204: If yes, determine the initial control amount according to the first straight line on the first coordinate axis;

[0030] S205: If not, determine the initial control amount according to the second straight line on the first coordinate axis.

[0031] Preferably, the initial control quantity setting of the large range set point also includes:

[0032] S206, the control valve moves to the third preset valve position, the second preset valve position and the first preset valve position in sequence according to the downstroke path, and determines the corresponding fourth control amount, fifth control amount and sixth control amount;

[0033] S207, fitting a third straight line on the first coordinate axis according to the first preset valve position, the sixth control amount, the second preset valve position, and the fifth control amount, and fitting a fourth straight line on the first coordinate axis according to the second preset valve position, the fifth control amount, the third preset valve position, and the fourth control amount;

[0034] S208, determining whether the target valve position is less than the second preset valve position;

[0035] S209: If yes, determine the initial control amount according to the third straight line on the first coordinate axis;

[0036] S210: If not, determine the initial control amount according to the fourth straight line on the first coordinate axis.

[0037] Preferably, the positioner self-tuning method further comprises: initial control quantity tuning of a small range set point;

[0038] The initial control quantity setting of the small range set point includes:

[0039] S301, the control valve is moved to the first preset valve position, the second preset valve position and the third preset valve position in sequence according to the upstroke path, and the corresponding first control amount increment, second control amount increment and third control amount increment are determined, wherein the first control amount increment, the second control amount increment and the third control amount increment are control amounts added at each stop valve position to make the absolute value of the difference between the current valve position of the valve and the original stop valve position greater than the fourth preset difference;

[0040] S302, fitting a fifth straight line on the second coordinate axis according to the first preset valve position, the first control amount increment, the second preset valve position, and the second control amount increment, and fitting a sixth straight line on the second coordinate axis according to the second preset valve position, the second control amount increment, the third preset valve position, and the third control amount increment, wherein the abscissa of the second coordinate axis is the valve position, and the ordinate is the control amount increment;

[0041] S303, determining whether the target valve position is less than the second preset valve position;

[0042] S304: If yes, determine the initial control amount according to the fifth straight line on the second coordinate axis and the current control amount of the corresponding valve position;

[0043] S305: If not, determine the initial control amount according to the sixth straight line on the second coordinate axis and the current control amount of the corresponding valve position.

[0044] Preferably, the positioner self-tuning method further comprises: initial control quantity tuning of a small range set point;

[0045] The initial control quantity setting of the small range set point includes:

[0046] S306, the control valve moves to the third preset valve position, the second preset valve position and the first preset valve position in sequence according to the downstroke path, and determines the corresponding fourth control amount increment, fifth control amount increment and sixth control amount increment, wherein the fourth control amount increment, the fifth control amount increment and the sixth control amount increment are respectively the control amounts reduced at each stop valve position in order to make the absolute value of the difference between the current valve position of the valve and the original stop valve position greater than the fourth preset difference;

[0047] S307, fitting a seventh straight line on the second coordinate axis according to the third preset valve position, the fourth control amount increment and the second preset valve position and the fifth control amount increment, and fitting an eighth straight line on the second coordinate axis according to the second preset valve position, the fifth control amount increment and the first preset valve position and the sixth control amount increment;

[0048] S308, determining whether the target valve position is less than the second preset valve position;

[0049] S309: If yes, determine the initial control amount according to the seventh straight line on the second coordinate axis and the current control amount of the corresponding valve position;

[0050] S310: If not, determine the initial control amount according to the eighth straight line on the second coordinate axis and the current control amount of the corresponding valve position.

[0051] Preferably, the positioner self-tuning method further comprises: actuator type tuning;

[0052] The actuator type setting includes:

[0053] S401, controlling the exhaust with a minimum control amount, and collecting a first pressure value and a fifth valve position after a first preset time period;

[0054] S402, controlling the intake air with a maximum control amount, and continuously collecting the second pressure value and the sixth valve position according to the first preset period within the first preset time period;

[0055] S403, determining whether the second pressure value is greater than the first pressure value and the fifth valve position is greater than the sixth valve position;

[0056] S404: If yes, determine that the actuator is in positive action;

[0057] S405: If not, determine that the actuator is in a reactionary state.

[0058] Preferably, the positioner self-tuning method further comprises: travel range tuning;

[0059] The travel range setting includes:

[0060] S501, controlling the exhaust with a minimum control amount, and collecting the current position of the valve once every second preset period during the exhaust process;

[0061] S502: When the current valve positions collected in two adjacent time periods are the same, determining the current valve positions corresponding to the adjacent time periods as a first valve position boundary value;

[0062] S503, controlling the air intake with the maximum control amount, and collecting the current position of the valve once every second preset period during the air intake process;

[0063] S504, when the current valve positions collected in two adjacent time periods are the same, determining the current valve positions corresponding to the adjacent time periods as the second valve position boundary value;

[0064] S505: Determine the difference between the first valve position boundary value and the second valve position boundary value as the travel range.

[0065] The implementation of the present invention has the following beneficial effects:

[0066] Set the current position of the valve to the initial position, and control the intake with the first set control amount; control the valve to move to the target valve position, determine the current valve position speed and the current valve position at this moment to be the first valve position speed and the first valve position respectively, and control the exhaust with the second set control amount; control the current valve position speed to be reduced to zero, and determine the current valve position at this moment to be the second valve position; determine whether the absolute value of the difference between the second valve position and the first valve position is greater than the first preset difference; if not, determine that the first valve position speed is the safe speed. In this way, the difference between the second valve position when the current valve position speed is reduced to zero and the first valve position when the valve moves to the target valve position can be compared to determine whether the first valve position speed when the valve moves to the target valve position is the safe speed, and the safe speed can be set, thereby reducing the valve position overshoot, and further improving the valve position control accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0068] Figure 1-1 and Figure 1-2 It is a schematic diagram of an embodiment of the safety speed setting of the present invention;

[0069] Figure 2-1 and Figure 2-2 is a schematic diagram of an embodiment of the initial control adjustment of a large range of set points of the present invention;

[0070] Figure 3-1 and Figure 3-2 It is a schematic diagram of an embodiment of the initial control adjustment of a small range set point of the present invention;

[0071] Figure 4 It is a schematic diagram of an embodiment of the actuator type setting of the present invention;

[0072] Figure 5 It is a schematic diagram of an embodiment of the travel range setting of the present invention;

[0073] Figure 6It is a flow chart of the self-tuning method of the intelligent valve positioner of a nuclear power plant according to the present invention. DETAILED DESCRIPTION

[0074] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention are now described in detail with reference to the accompanying drawings. Features defined as "first", "second", "third", etc. may explicitly or implicitly include one or more of the features. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0075] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0076] The invention provides a self-tuning method for an intelligent valve positioner in a nuclear power plant, which is used for realizing the setting of a safe speed to reduce the situation of valve position overshoot, thereby improving the valve position control accuracy.

[0077] like Figure 1-1 As shown, an embodiment of the self-tuning method of the intelligent valve positioner of a nuclear power plant of the present invention includes: safety speed tuning; the specific steps of the safety speed tuning include:

[0078] S101, setting the current position of the valve to an initial position, and controlling the air intake with a first set control amount;

[0079] S102, controlling the valve to move to the target valve position, determining that the current valve position speed and the current valve position at this moment are the first valve position speed and the first valve position respectively, and controlling the exhaust with the second set control amount;

[0080] S103, controlling the current speed of the valve position to decrease to zero, and determining the current position of the valve at this moment to be the second valve position;

[0081] S104, determining whether the absolute value of the difference between the second valve position and the first valve position is greater than a first preset difference;

[0082] S105: If not, determine that the first valve position speed is a safe speed.

[0083] Specifically, first determine whether the current position of the valve is in the initial position, and the initial position can be set to 0% valve position. If so, continue to intake air with the first set control amount to push the valve to move. The first set control amount can be set to the maximum control amount, and the maximum control amount is the maximum amount of air used for intake. After a period of intake, the valve will move to the target valve position, and the target valve position can be set to 50% valve position. At this time, the current speed and current position of the valve when it reaches the 50% valve position can be recorded. Since the valve may deviate in the process of moving to the 50% valve position, the current position of the valve may be the same as the target valve position or may be different, such as: the current position of the valve is 50% valve position or 51% valve position. And determine the current speed of the valve position as the first valve position speed V 1 , the current valve position is the first valve position L 1 .

[0084] Then, exhaust is continued with the second set control amount. During the exhaust process, the valve will move in the opposite direction, such as: during the intake process, the valve moves from 0% valve position to 50% valve position, and during the exhaust process, the valve moves from 50% valve position to 45% valve position. The second set control amount can be set to the minimum control amount, which is the maximum air volume for exhaust. During the exhaust process, the movement speed of the valve will gradually decrease until it is reduced to zero. At this time, it can be determined that the current position of the valve is the second valve position L 2 .

[0085] Finally, set the second valve position L 1 With the first valve position L 2 Make a difference and determine whether the absolute value of the difference is greater than a first preset difference. The first preset difference can be set to 3% of the valve position. 2 -L 1 |≤3%, it can be determined that the valve has reached the first valve position L 1 The first valve position speed V 1 For safe speed, complete the setting of safe speed.

[0086] In another possible implementation, when |L 2 -L 1 |>3%, it means the valve reaches the first valve position L 1 The first valve position speed V 1 It is not a safe speed. At this time, steps S101 to S105 can be repeated, and the control amount of controlling the intake air is reduced once and updated to the first set control amount each time step S101 is repeated. For example, the intake air is controlled with the control amount 1000 for the first time. If |L 2 -L 1|≤3%, when the valve is at 0% valve position, reduce the control amount by 100, control the intake air with the control amount of 900, and repeat steps S102 to S105 until |L is satisfied 2 -L 1 |≤3%, the safe speed can be set.

[0087] Optional, such as Figure 1-2 As shown, the specific steps of safety speed setting in this embodiment also include:

[0088] S106, when the Bang-Bang control ends, determining that the current position of the valve at this moment is the third valve position;

[0089] S107, when PID control starts, determining that the current position of the valve at this moment is the fourth valve position;

[0090] S108, determining whether the absolute value of the difference between the fourth valve position and the third valve position is greater than a second preset difference;

[0091] S109: If yes, reduce the safety speed value.

[0092] S110, if not, determining whether the absolute value of the difference between the fourth valve position and the third valve position is less than a third preset difference;

[0093] S111 . When the absolute value of the difference between the fourth valve position and the third valve position is less than a third preset difference, increase the value of the safety speed.

[0094] Specifically, in the process of switching from Bang-Bang control to PID control, the current valve position at the end of Bang-Bang control and the current valve position at the start of PID control are recorded and determined as the third valve position L 3 and the fourth valve position L 4 Then set the fourth valve position L 4 With the third valve position L 3 The difference is made, and the absolute value of the difference is compared with the second preset difference to determine whether overshoot or undershoot will occur during the process of switching from Bang-Bang control to PID control. The second preset difference can be set to 3%. For example: when |L 4 -L 3 |>3%, it means that overshoot may occur in the process of switching from Bang-Bang control to PID control. In this case, the safety speed value can be reduced to obtain the latest safety speed V 1 '=V 1 -V x , the V x is the preset value, which can be set to 0.01. 4 -L 3|≤3%, it means that undershoot may occur during the process of switching from Bang-Bang control to PID control. In this case, the fourth valve position L 4 With the third valve position L 3 The absolute value of the difference between |L and |L is further compared with the third preset difference to further determine whether an undershoot will occur. The third preset difference can be set to 1%. 4 -L 3 |<1%, the safety speed value can be increased to obtain the latest safety speed V 1 ”=V 1 +V x In this way, the safety speed can be dynamically adjusted during the switch from Bang-Bang control to PID control to reduce overshoot and adjustment time during the control process, and the overall anti-interference ability of the positioner can be improved.

[0095] like Figure 2-1 As shown, another embodiment of the self-tuning method of the intelligent valve positioner of a nuclear power plant of the present invention includes: initial control quantity tuning of a large range of set points; the specific steps of the large range of set points include:

[0096] S201, the control valve moves to the first preset valve position, the second preset valve position and the third preset valve position in sequence according to the upstroke path, and determines the corresponding first control amount, the second control amount and the third control amount;

[0097] S202, fitting a first straight line on a first coordinate axis according to the first preset valve position, the first control amount, and the second preset valve position and the second control amount, and fitting a second straight line on the first coordinate axis according to the second preset valve position, the second control amount, and the third preset valve position and the third control amount, wherein the abscissa of the first coordinate axis is the valve position, and the ordinate is the control amount;

[0098] S203, determining whether the target valve position is less than a second preset valve position;

[0099] S204, if yes, determining the initial control amount according to the first straight line on the first coordinate axis;

[0100] S205: If not, determine the initial control amount according to the second straight line on the first coordinate axis.

[0101] Specifically, the initial control amount of the wide range set point can be adjusted to improve the applicability of the positioner under different conditions. The initial control amount represents the initial value of the incremental PID, and the wide range set point indicates that the valve position difference between the target valve position and the current valve position is greater than the preset range. For example, if the target valve position is 60%, the current valve position is 5%, and the difference between the two is 55%, and the preset range is 30%, then the target valve position can be determined as the wide range set point.

[0102] The upstroke path represents the path of the valve moving from the closed end to the open end. The first preset valve position, the second preset valve position and the third preset valve position in the upstroke path can be set to 10% valve position, 50% valve position and 90% valve position respectively. When the valve moves to the 10% valve position, 50% valve position and 90% valve position in sequence, the current control amount corresponding to the different valve positions can be obtained, which are the first control amount U c1 , the second control quantity U c2 And the third control quantity U c3 Then according to (10%, U c1 ) and (50%, U c2 ) fits the slope K on the first coordinate axis u1 , the deviation is B u1 The first straight line, the function of which is y 1 =K u1 x+B u1 . And according to (50%, U c2 ) and (90%, U c3 ) fits the slope K on the first coordinate axis u2 , the deviation is B u2 The second straight line, the function of which is y 2 =K u2 x+B u2 The horizontal coordinate of the first coordinate axis is the valve position, and the vertical coordinate is the current control amount of the incremental PID. When the target valve position is less than 50%, the initial value u of the incremental PID 0 The first straight line y 1 =K u1 x+B u1 to determine; when the target valve position is greater than 50%, the initial value u of the incremental PID 0 The second straight line y 2 =K u2 x+B u2 to be sure.

[0103] Optional, such as Figure 2-2 As shown, the specific steps of setting the initial control amount of the large-range set point in this embodiment also include:

[0104] S206, the control valve moves to the third preset valve position, the second preset valve position and the first preset valve position in sequence according to the downstroke path, and determines the corresponding fourth control amount, fifth control amount and sixth control amount;

[0105] S207, fitting a third straight line on the first coordinate axis according to the first preset valve position, the sixth control amount, the second preset valve position, and the fifth control amount, and fitting a fourth straight line on the first coordinate axis according to the second preset valve position, the fifth control amount, the third preset valve position, and the fourth control amount;

[0106] S208, determining whether the target valve position is less than a second preset valve position;

[0107] S209, if yes, determine the initial control amount according to the third straight line on the first coordinate axis;

[0108] S210: If not, determine the initial control amount according to the fourth straight line on the first coordinate axis.

[0109] Specifically, the downstroke path represents the path of the valve moving from the open end to the closed end. The third preset valve position, the second preset valve position and the first preset valve position in the downstroke path can be set to 90% valve position, 50% valve position and 10% valve position respectively. When the valve moves to 90% valve position, 50% valve position and 10% valve position in sequence, the current control amount corresponding to the different valve positions can be obtained, which are the third control amount D c1 , the fourth control amount D c2 And the fifth control amount D c3 Then according to (10%, D c3 ) and (50%, D c2 ) fits the slope K on the first coordinate axis d1 , the deviation is B d1 The third straight line of the third straight line is the function of y 3 =K d1 x+B d1 . And according to (50%, D c2 ) and (90%, D c1 ) fits the slope K on the first coordinate axis d2 , the deviation is B d2 The fourth straight line of the fourth straight line is the function of y 4 =K d2 x+B d2 When the target valve position is less than 50%, the initial value u of the incremental PID 0 The third straight line y 3 =K d1 x+B d1 to determine; when the target valve position is greater than 50%, the initial value u of the incremental PID 0 It can be seen from the fourth straight line y 4 =K d2 x+B d2 to be sure.

[0110] like Figure 3-1As shown, another embodiment of the self-tuning method of the intelligent valve positioner of a nuclear power plant of the present invention includes: initial control quantity tuning of a small range set point; the specific steps of the small range set point include:

[0111] S301, the control valve is moved to the first preset valve position, the second preset valve position and the third preset valve position in sequence according to the upstroke path, and the corresponding first control amount increment, second control amount increment and third control amount increment are determined, and the first control amount increment, the second control amount increment and the third control amount increment are respectively the control amounts added at each stop valve position to make the absolute value of the difference between the current valve position of the valve and the original stop valve position greater than the fourth preset difference;

[0112] S302, fitting a fifth straight line on the second coordinate axis according to the first preset valve position, the first control amount increment, and the second preset valve position, the second control amount increment, and fitting a sixth straight line on the second coordinate axis according to the second preset valve position, the second control amount increment, and the third preset valve position, the third control amount increment, wherein the abscissa of the second coordinate axis is the valve position, and the ordinate is the control amount increment;

[0113] S303, determining whether the target valve position is less than a second preset valve position;

[0114] S304, if yes, determine the initial control amount according to the fifth straight line on the second coordinate axis and the current control amount of the corresponding valve position;

[0115] S305: If not, determine the initial control amount according to the sixth straight line on the second coordinate axis and the current control amount of the corresponding valve position.

[0116] Specifically, the small range set point indicates that the valve position difference between the target valve position and the current valve position is less than the preset range. For example, the target valve position is 30%, the current valve position is 5%, the valve position difference between the two is 25%, and the preset range is 30%. Then, the target valve position can be determined as the small range set point.

[0117] The first preset valve position, the second preset valve position and the third preset valve position in the upward stroke path can be set to 10% valve position, 50% valve position and 90% valve position respectively. When the valve moves to 10% valve position, 50% valve position and 90% valve position respectively, the current control amount increment corresponding to the different valve positions can be obtained, which are the first control amount increment ΔU c1 , the second control amount increment ΔU c2 and the third control amount increment ΔU c3 For example: when the valve moves to 10% of the valve position, record the current control amount U c4 and the original stop valve position L, and then increase the control amount ΔU at intervals of 5s c1, at this time, the valve moves to the current valve position L'. If the absolute value of the difference between the current valve position L' and the original stop valve position L is greater than the fourth preset difference, which can be set to 1%, then the current control amount U corresponding to the current valve position L' is recorded. c5 , the first control quantity increment is ΔU c1 =U c5 -U c4 Similarly, the corresponding second control amount increment ΔU can be obtained c2 and the third control amount increment ΔU c3 .

[0118] According to (10%, ΔU c1 ) and (50%, ΔU c2 ) fits the slope ΔK on the second coordinate axis u1 , the deviation is ΔB u1 The fifth straight line of the fifth straight line is the function of y 5 =ΔK u1 x+ΔB u1 . And according to (50%, ΔU c2 ) and (90%, ΔU c3 ) fits the slope ΔK on the second coordinate axis u2 , the deviation is ΔB u2 The sixth straight line of the sixth straight line is the function of y 6 =ΔK u2 x+ΔB u2 The horizontal coordinate of the second coordinate axis is the valve position, and the vertical coordinate is the control amount increment. When the target valve position is less than 50%, the initial value u of the incremental PID 0 It can be determined by the fifth straight line and the current control amount, such as: when the valve is in the valve position, the corresponding current control amount is u cur , then the initial value u of the incremental PID 0 You can use y 5 '=u cur +ΔK u1 x+ΔB u1 to determine; when the target valve position is greater than 50%, the initial value u of the incremental PID 0 It can be determined by the sixth straight line and the current control amount, that is, y 6 '=u cur +ΔK u2 x+ΔB u2 .

[0119] Optional, such as Figure 3-2 As shown, the specific steps of initial control amount adjustment of the small range set point in this embodiment also include:

[0120] S306, the control valve moves to the third preset valve position, the second preset valve position and the first preset valve position in sequence according to the downstroke path, and determines the corresponding fourth control amount increment, fifth control amount increment and sixth control amount increment, which are the control amounts reduced at each stop valve position to make the absolute value of the difference between the current valve position of the valve and the original stop valve position greater than the fourth preset difference;

[0121] S307, fitting a seventh straight line on the second coordinate axis according to the third preset valve position, the fourth control amount increment, the second preset valve position, and the fifth control amount increment, and fitting an eighth straight line on the second coordinate axis according to the second preset valve position, the fifth control amount increment, the first preset valve position, and the sixth control amount increment;

[0122] S308, determining whether the target valve position is less than a second preset valve position;

[0123] S309, if yes, determine the initial control amount according to the seventh straight line on the second coordinate axis and the current control amount of the corresponding valve position;

[0124] S310: If not, determine the initial control amount according to the eighth straight line on the second coordinate axis and the current control amount of the corresponding valve position.

[0125] The third preset valve position, the second preset valve position and the first preset valve position in the downstroke path can be set to 90% valve position, 50% valve position and 10% valve position respectively. When the valve moves to 90% valve position, 50% valve position and 10% valve position respectively, the current control amount increment corresponding to the different valve positions can be obtained, which are the fourth control amount increment ΔD c4 , the fifth control amount increment ΔD c5 and the sixth control amount increment ΔD c6 For example: when the valve moves to 90% of the valve position, record the current control amount U c4 and the original stop valve position L, and then reduce the control amount ΔD after an interval of 5s c4 , at this time, the valve moves to the current valve position L'. If the absolute value of the difference between the current valve position L' and the original stop valve position L is greater than the fourth preset difference, which can be set to 1%, then the current control amount U corresponding to the current valve position L' is recorded. c5 , the fourth control amount increment is ΔU c4 =U c4 -U c5 Similarly, the corresponding fifth control amount increment ΔD can be obtained c5 and the sixth control amount increment ΔD c6 .

[0126] According to (90%, ΔD c4 ) and (50%, ΔDc5 ) fits the slope ΔK on the second coordinate axis d1 , the deviation is ΔB d1 The seventh straight line, the function of the seventh straight line is y 7 =ΔK d1 x+ΔB d1 . And according to (50%, ΔD c5 ) and (10%, ΔD c4 ) fits the slope ΔK on the second coordinate axis d2 , the deviation is ΔB d2 The eighth straight line of the eighth straight line is the function of y 8 =ΔK d2 x+ΔB d2 When the target valve position is less than 50%, the initial value u of the incremental PID 0 It can be determined by the seventh straight line and the current control amount, that is, y 7 '=u cur +ΔK d1 x+ΔB d1 ; When the target valve position is greater than 50%, the initial value u of the incremental PID 0 It can be determined by the eighth straight line and the current control amount, that is, y 8 '=u cur +ΔK d2 x+ΔB d2 .

[0127] like Figure 4 As shown, another embodiment of the self-tuning method of the intelligent valve positioner of a nuclear power plant of the present invention includes: actuator type tuning; the specific steps of actuator type tuning include:

[0128] S401, controlling the exhaust with a minimum control amount, and collecting a first pressure value and a fifth valve position after a first preset time period;

[0129] S402, controlling the intake air with a maximum control amount, and continuously collecting the second pressure value and the sixth valve position according to a first preset period within a first preset time period;

[0130] S403, determining whether the second pressure value is greater than the first pressure value and the fifth valve position is greater than the sixth valve position;

[0131] S404: If yes, determine that the actuator is in positive action;

[0132] S405: If not, determine that the actuator is in a reactionary state.

[0133] Specifically, the actuator type of the positioner can be adjusted to achieve automatic identification without manual calibration by the user. First, exhaust is continuously performed at a minimum control amount within a first preset time period, and the first preset time period can be set to 5 seconds. After continuous exhaust for 5 seconds, the first pressure value P output by the positioner is collected through an analog-to-digital converter (ADC) 1 and the fifth valve position L of the current valve position 5 Then, the air is continuously introduced at the maximum control amount for 5 seconds. During the 5 seconds of continuous air introduction, the second pressure value P output by the positioner is collected by ADC according to the first preset period. 2 and the sixth valve position L of the current valve position 6 , the first preset period can be set to 1s. 2 -P 1 >0&L 2 -L 1 When >0, it can be determined that the actuator is in positive action, otherwise it is determined that the actuator is in negative action.

[0134] like Figure 5 As shown, another embodiment of the self-tuning method of the intelligent valve positioner of a nuclear power plant of the present invention includes: travel range tuning; the specific steps of the travel range tuning include:

[0135] S501, controlling the exhaust with a minimum control amount, and collecting the current position of the valve once every second preset period during the exhaust process;

[0136] S502: When the current valve positions collected in two adjacent time periods are the same, determining the current valve positions corresponding to the adjacent time periods as the first valve position boundary value;

[0137] S503, controlling the air intake with the maximum control amount, and collecting the current position of the valve once every second preset period during the air intake process;

[0138] S504, when the current valve positions collected in two adjacent time periods are the same, determining the current valve positions corresponding to the adjacent time periods as the second valve position boundary value;

[0139] S505: Determine the difference between the first valve position boundary value and the second valve position boundary value as the travel range.

[0140] Specifically, the travel range of the positioner can be adjusted to achieve automatic identification without manual calibration by the user. First, the continuous exhaust is controlled with the minimum control amount, and the current valve position is collected once every second preset period through ADC during the continuous exhaust process. The second preset period can be set to 3s. For example, during the continuous exhaust process, the valve position value is collected once every 3s through ADC, and a total of 4 times are collected. The valve position values ​​obtained are L7 =10%, L 8 =50%, L 9 =0%, L 10 =0%, due to L 9 With L 10 adjacent and identical, so L 9 Then, the continuous air intake is controlled with the maximum control amount, and the current valve position is collected once every second preset period through ADC during the continuous air intake process. The second preset period can be set to 3s. For example, during the continuous air intake process, the valve position value is collected once every 3s through ADC, and a total of 4 times are collected. The valve position values ​​obtained are L 11 =90%, L 12 =100%, L 13 =100%, L 14 = 100%, due to L 12 With L 13 adjacent and identical, so L 12 Finally, the stroke range can be determined as L according to the first valve position boundary value and the second valve position boundary value. 9 -L 12 .

[0141] like Figure 6 As shown, the self-tuning method of the intelligent valve positioner of a nuclear power plant of the present invention can complete all tuning according to the following steps: first, the actuator type is tuned; then the travel range is tuned; then the safety speed is tuned; then the initial control quantity of the large-range setting point is tuned; and finally, the initial control quantity of the small-range setting point is tuned.

[0142] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. A self-tuning method for an intelligent valve positioner in a nuclear power plant, characterized in that: include: Safe speed setting; The safety speed setting includes: S101, setting the current position of the valve to an initial position, and controlling the air intake with a first set control amount; S102, controlling the valve to move to a target valve position, determining that the current valve position speed and the current valve position at this moment are respectively the first valve position speed and the first valve position, and controlling the exhaust with a second set control amount; S103, controlling the current speed of the valve position to decrease to zero, and determining the current position of the valve at this moment to be the second valve position; S104, determining whether the absolute value of the difference between the second valve position and the first valve position is greater than a first preset difference; S105: If not, determine that the first valve position speed is a safe speed.

2. The method for self-tuning the intelligent valve positioner of a nuclear power plant according to claim 1, characterized in that: After step S105, the safety speed setting further includes: S106, when the hysteresis control ends, determining that the current position of the valve at this moment is the third valve position; S107, when proportional-integral-differential control starts, determining that the current position of the valve at this moment is the fourth valve position; S108, determining whether the absolute value of the difference between the fourth valve position and the third valve position is greater than a second preset difference; S109: If yes, reduce the value of the safety speed.

3. The method for self-tuning the intelligent valve positioner of a nuclear power plant according to claim 2, characterized in that: After step S109, the safety speed setting further includes: S110, if not, determining whether the absolute value of the difference between the fourth valve position and the third valve position is less than a third preset difference; S111. When the absolute value of the difference between the fourth valve position and the third valve position is less than a third preset difference, increase the value of the safety speed.

4. The method for self-tuning the intelligent valve positioner of a nuclear power plant according to claim 1, characterized in that: After step S104, the safety speed setting further includes: If yes, set the current position of the valve to return to the initial position, adjust the value of the control amount and update it to the first set control amount; Repeat steps S102 to S105.

5. The method for self-tuning the intelligent valve positioner of a nuclear power plant according to claim 1, characterized in that: The method for self-tuning the intelligent valve positioner of a nuclear power plant further includes: initial control quantity tuning of a large range of set points; The initial control quantity setting of the large range set point includes: S201, the control valve moves to the first preset valve position, the second preset valve position and the third preset valve position in sequence according to the upstroke path, and determines the corresponding first control amount, the second control amount and the third control amount; S202, fitting a first straight line on a first coordinate axis according to the first preset valve position, the first control amount, the second preset valve position, and the second control amount, and fitting a second straight line on the first coordinate axis according to the second preset valve position, the second control amount, the third preset valve position, and the third control amount, wherein the abscissa of the first coordinate axis is the valve position, and the ordinate is the control amount; S203, determining whether the target valve position is less than the second preset valve position; S204: If yes, determine the initial control amount according to the first straight line on the first coordinate axis; S205: If not, determine the initial control amount according to the second straight line on the first coordinate axis.

6. The method for self-tuning the intelligent valve positioner of a nuclear power plant according to claim 5, characterized in that: The initial control quantity setting of the large range set point also includes: S206, the control valve moves to the third preset valve position, the second preset valve position and the first preset valve position in sequence according to the downstroke path, and determines the corresponding fourth control amount, fifth control amount and sixth control amount; S207, fitting a third straight line on the first coordinate axis according to the first preset valve position, the sixth control amount, the second preset valve position, and the fifth control amount, and fitting a fourth straight line on the first coordinate axis according to the second preset valve position, the fifth control amount, the third preset valve position, and the fourth control amount; S208, determining whether the target valve position is less than the second preset valve position; S209: If yes, determine the initial control amount according to the third straight line on the first coordinate axis; S210: If not, determine the initial control amount according to the fourth straight line on the first coordinate axis.

7. The method for self-tuning the intelligent valve positioner of a nuclear power plant according to claim 1, characterized in that: The self-tuning method of the intelligent valve positioner of a nuclear power plant further includes: initial control quantity tuning of a small range set point; The initial control quantity setting of the small range set point includes: S301, the control valve is moved to the first preset valve position, the second preset valve position and the third preset valve position in sequence according to the upstroke path, and the corresponding first control amount increment, second control amount increment and third control amount increment are determined, wherein the first control amount increment, the second control amount increment and the third control amount increment are control amounts added at each stop valve position to make the absolute value of the difference between the current valve position of the valve and the original stop valve position greater than the fourth preset difference; S302, fitting a fifth straight line on the second coordinate axis according to the first preset valve position, the first control amount increment, the second preset valve position, and the second control amount increment, and fitting a sixth straight line on the second coordinate axis according to the second preset valve position, the second control amount increment, the third preset valve position, and the third control amount increment, wherein the abscissa of the second coordinate axis is the valve position, and the ordinate is the control amount increment; S303, determining whether the target valve position is less than the second preset valve position; S304: If yes, determine the initial control amount according to the fifth straight line on the second coordinate axis and the current control amount of the corresponding valve position; S305: If not, determine the initial control amount according to the sixth straight line on the second coordinate axis and the current control amount of the corresponding valve position.

8. The method for self-tuning the intelligent valve positioner of a nuclear power plant according to claim 7, characterized in that: The self-tuning method of the intelligent valve positioner of a nuclear power plant further includes: initial control quantity tuning of a small range set point; The initial control quantity setting of the small range set point includes: S306, the control valve moves to the third preset valve position, the second preset valve position and the first preset valve position in sequence according to the downstroke path, and determines the corresponding fourth control amount increment, fifth control amount increment and sixth control amount increment, wherein the fourth control amount increment, the fifth control amount increment and the sixth control amount increment are respectively the control amounts reduced at each stop valve position in order to make the absolute value of the difference between the current valve position of the valve and the original stop valve position greater than the fourth preset difference; S307, fitting a seventh straight line on the second coordinate axis according to the third preset valve position, the fourth control amount increment and the second preset valve position and the fifth control amount increment, and fitting an eighth straight line on the second coordinate axis according to the second preset valve position, the fifth control amount increment and the first preset valve position and the sixth control amount increment; S308, determining whether the target valve position is less than the second preset valve position; S309: If yes, determine the initial control amount according to the seventh straight line on the second coordinate axis and the current control amount of the corresponding valve position; S310: If not, determine the initial control amount according to the eighth straight line on the second coordinate axis and the current control amount of the corresponding valve position.

9. The method for self-tuning an intelligent valve positioner in a nuclear power plant according to any one of claims 1 to 8, characterized in that: The self-tuning method of the intelligent valve positioner of a nuclear power plant further comprises: actuator type tuning; The actuator type setting includes: S401, controlling the exhaust with a minimum control amount, and collecting a first pressure value and a fifth valve position after a first preset time period; S402, controlling the intake air with a maximum control amount, and continuously collecting the second pressure value and the sixth valve position according to the first preset period within the first preset time period; S403, determining whether the second pressure value is greater than the first pressure value and the fifth valve position is greater than the sixth valve position; S404: If yes, determine that the actuator is in positive action; S405: If not, determine that the actuator is in a reactionary state.

10. The method for self-tuning an intelligent valve positioner in a nuclear power plant according to any one of claims 1 to 8, characterized in that: The self-tuning method of the intelligent valve positioner of a nuclear power plant further includes: travel range tuning; The travel range setting includes: S501, controlling the exhaust with a minimum control amount, and collecting the current position of the valve once every second preset period during the exhaust process; S502: When the current valve positions collected in two adjacent time periods are the same, determining that the current valve positions corresponding to the adjacent time periods are the first valve position boundary values; S503, controlling the air intake with the maximum control amount, and collecting the current position of the valve once every second preset period during the air intake process; S504: When the current valve positions collected in two adjacent time periods are the same, determining that the current valve positions corresponding to the adjacent time periods are the second valve position boundary values; S505: Determine the difference between the first valve position boundary value and the second valve position boundary value as the travel range.

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