An intelligent control method and system for an electric butterfly valve

Abstract

The present invention relates to the field of intelligent control technology, and particularly to an intelligent control method and system for an electric butterfly valve, including obtaining a set pressure value and actual pressure data; calculating the current pressure deviation; calculating the current pressure deviation using a PID control algorithm; determining the opening degree of the butterfly valve according to the control value output by the PID; controlling an electric actuator to adjust the corresponding butterfly valve according to the opening degree; monitoring the position of the butterfly valve and the fluid pressure within a predicted time after adjustment; evaluating the accuracy of the PID control algorithm according to the position of the butterfly valve and the fluid pressure; determining a PID parameter adjustment strategy according to the evaluation result; monitoring the response speed of the butterfly valve and the pressure overshoot after response after the adjustment strategy; verifying the effectiveness of the PID parameter adjustment strategy according to the response speed and the pressure overshoot; optimizing the PID parameter adjustment strategy according to the verification result; monitoring the pressure value of the butterfly valve after the optimization of the PID parameter adjustment strategy, and determining a correction measure. The present invention improves the control accuracy and stability of the butterfly valve.

Description

Technical Field

[0001] The present invention relates to the field of intelligent control technology, and particularly to an intelligent control method and system for an electric butterfly valve. Background Art

[0002] A butterfly valve is a control valve widely used in fluid pipelines. It has a simple structure, quick opening and closing, and a small fluid resistance. The operating principle of the butterfly valve is to control the fluid flow by rotating the butterfly plate, and it can achieve flow regulation and throttling control for medium to large diameters. Butterfly valves are widely used in fields such as chemical industry, petroleum, water treatment, heating, and air conditioning, and are a common fluid control device. The operating principle of the existing butterfly valve is to control the fluid flow by rotating the butterfly plate. Therefore, in some applications that require precise control, the butterfly valve may not provide sufficiently precise flow regulation. The tolerance of the butterfly valve under harsh working conditions is limited, and problems such as thermal expansion and contraction, and corrosion may occur, resulting in inaccurate measurement data, and further causing the butterfly valve to be unable to achieve accurate intelligent regulation.

[0003] Chinese Patent Publication No.: CN110645376B discloses an intelligent butterfly valve, which relates to the technical field of butterfly valves, and includes a valve body, a valve stem, and a valve plate. A valve hole for fluid passage is provided in the valve body, a valve stem through hole for the valve stem to pass through is provided on the valve body, the valve plate is positioned in the valve hole through the valve stem, and the valve stem drives the valve plate to rotate forward and backward. A valve plate rotation limiting mechanism is provided in the valve body. When the valve plate is in the closed state, the valve plate divides the valve hole into an air inlet chamber and an air outlet chamber. The valve stem includes a shaft sleeve, an upper rotating shaft, and a lower rotating shaft. A positioning shaft, a sliding shaft, and a return spring are provided in the shaft sleeve. At least one valve plate anti-rotation mechanism is provided in the valve plate and the valve stem. The present invention provides an intelligent butterfly valve that can reduce the shear stress on the valve stem when the valve plate is in the closed state, and at the same time can ensure that the valve plate will not undergo destructive flipping. However, this solution does not consider the situation that in applications that require precise control, the butterfly valve may not provide sufficiently precise flow regulation, and the accuracy of intelligent regulation of the butterfly valve is low. Summary of the Invention

[0004] Therefore, the present invention provides an intelligent control method and system for an electric butterfly valve to overcome the problem that the butterfly valve in the prior art cannot achieve accurate intelligent regulation.

[0005] To achieve the above object, the present invention provides an intelligent control method for an electric butterfly valve. The method includes:

[0006] Step S1, obtaining a set pressure value and actual pressure data of a pressure sensor at the butterfly valve;

[0007] Step S2, comparing the set pressure value with the actual pressure data and calculating the current pressure deviation;

[0008] Step S3, calculate the current pressure deviation using the PID control algorithm;

[0009] Step S4, determine the opening degree of the butterfly valve according to the control value output by the PID;

[0010] Step S5, control the electric actuator to adjust the corresponding butterfly valve according to the opening degree;

[0011] Step S6, monitor the position of the butterfly valve and the fluid pressure within the predicted time after adjustment;

[0012] Step S7, evaluate the accuracy of the PID control algorithm according to the position of the butterfly valve and the fluid pressure;

[0013] Step S8, determine the PID parameter adjustment strategy according to the evaluation result, and control the electric actuator to adjust the corresponding butterfly valve;

[0014] Step S9, monitor the response speed of the butterfly valve and the pressure overshoot after response after the adjustment strategy;

[0015] Step S10, verify the effectiveness of the PID parameter adjustment strategy according to the response speed and the pressure overshoot;

[0016] Step S11, optimize the PID parameter adjustment strategy according to the verification result;

[0017] Step S12, monitor the pressure value of the butterfly valve after optimizing the PID parameter adjustment strategy, and judge whether the pressure value of the butterfly valve reaches the set pressure value, and determine the correction measure according to the judgment result.

[0018] Further, in the step S3, when calculating the current pressure deviation E using the PID control algorithm, obtain the historical pressure deviation, sum the historical pressure deviation and the current pressure deviation to obtain the integral term I, calculate the differential term D according to the current pressure deviation and the previous pressure deviation, and calculate the proportional term P according to the preset proportional parameter and the current pressure deviation;

[0019] Calculate the control value according to the current pressure deviation E, the proportional term P, the integral term I and the differential term D, where the control value = P×E + I + D.

[0020] Further, in the step S4, when determining the opening degree of the butterfly valve according to the control value output by the PID, judge the positive and negative of the control value A, where:

[0021] If A > 0, it is determined to increase the opening degree of the butterfly valve;

[0022] If A < 0, it is determined to decrease the opening degree of the butterfly valve;

[0023] If A = 0, it is determined that the opening degree of the butterfly valve does not need to be adjusted.

[0024] Further, in the step S7, when evaluating the accuracy of the PID control algorithm, the standard deviation P of the butterfly valve position and the standard deviation Q of the fluid pressure within a preset time are calculated respectively, and the standard deviation of the butterfly valve position and the standard deviation of the fluid pressure are compared with the standard deviation threshold P0 of the butterfly valve position and the standard deviation threshold Q0 of the fluid pressure respectively to determine whether the butterfly valve position and the fluid pressure are abnormal. Among them,

[0025] If P > P0, it is determined that the butterfly valve position fluctuates frequently;

[0026] If P ≤ P0, it is determined that the butterfly valve position is normal;

[0027] If Q > Q0, it is determined that the fluid pressure fluctuates greatly;

[0028] If Q ≤ Q0, it is determined that the fluid pressure is normal;

[0029] The accuracy of the PID control algorithm is evaluated according to the abnormal conditions of the butterfly valve position and the fluid pressure. Among them,

[0030] If both the butterfly valve position and the fluid pressure are normal, it is determined that the PID control algorithm is normal;

[0031] If the butterfly valve position fluctuates frequently and the fluid pressure fluctuates greatly, it is determined that the PID control algorithm is inaccurate;

[0032] If the butterfly valve position fluctuates frequently and the fluid pressure is normal, it is determined that the PID control algorithm is inaccurate;

[0033] If the butterfly valve position is normal and the fluid pressure fluctuates greatly, it is determined that the fluid state is abnormal, and the temperature and density of the fluid in the pipeline are detected.

[0034] Further, in the step S8, when determining the PID parameter adjustment strategy, the adjustment strategy is determined according to the factors when the PID control algorithm is inaccurate. Among them:

[0035] If the control value A output by the PID is 0, the actual differential term is increased, the adjustment coefficient v1 is set, 0.1 ≤ v1 ≤ 0.2 is set, and the adjusted differential term Dv0 = D + v1 × D;

[0036] If the butterfly valve position fluctuates frequently and the fluid pressure fluctuates greatly, the actual integral term is increased, the adjustment coefficient v2 is set, 0.1 ≤ v2 ≤ 0.5 is set, and the adjusted integral term Iv0 = I + v2 × I;

[0037] If the position of the butterfly valve fluctuates frequently and the fluid pressure is normal, increase the actual proportional term, set the adjustment coefficient v3, where 0.1 ≤ v3 ≤ 0.5, and the adjusted proportional term Pv0 = P + v3×P.

[0038] Further, in the step S10, when verifying the effectiveness of the PID parameter adjustment strategy, compare the response speed X and the pressure overshoot Y with the response speed threshold X0 and the pressure overshoot threshold Y0 respectively, where:

[0039] If X < X0, it is determined that the response speed of the butterfly valve is too slow;

[0040] If X ≥ X0, it is determined that the response speed of the butterfly valve is normal;

[0041] If Y > Y0, it is determined that the pressure overshoot of the butterfly valve is too large;

[0042] If Y ≤ Y0, it is determined that the pressure overshoot of the butterfly valve is normal;

[0043] Verify the effectiveness of the PID parameter adjustment strategy according to the abnormal conditions of the response speed and pressure overshoot of the butterfly valve, where:

[0044] If both the response speed and the pressure overshoot are normal, verify that the PID parameter adjustment strategy is effective;

[0045] If the response speed is too slow and the pressure overshoot is too large, it is determined that environmental factors cause the response speed to be too slow and the pressure overshoot to be too large, and check whether the electric actuator is damaged;

[0046] If the response speed is too slow and the pressure overshoot is normal, verify that the PID parameter adjustment strategy is ineffective;

[0047] If the response speed is normal and the pressure overshoot is too large, verify that the PID parameter adjustment strategy is ineffective.

[0048] Further, in the step S11, when optimizing the PID parameter adjustment strategy, optimize it according to the ineffective result of the PID parameter adjustment strategy, where:

[0049] If the response speed is too slow and the pressure overshoot is normal, expand the adjustment coefficient v3;

[0050] If the response speed is normal and the pressure overshoot is too large, reduce the adjustment coefficient v3

[0051] Further, in the step S12, when monitoring the butterfly valve pressure value after the PID parameter adjustment strategy is optimized and determining whether the butterfly valve pressure value reaches the set pressure value, the butterfly valve pressure value is compared with the set pressure value. If the butterfly valve pressure value does not reach the set pressure value, it is determined that the environmental factors of the butterfly valve are abnormal.

[0052] Further, when determining the correction measure according to the judgment result, if the environmental factors of the butterfly valve are abnormal, the temperature and density of the fluid and whether the detection sensor is faulty are detected.

[0053] On the other hand, the present invention also provides an intelligent control system for an electric butterfly valve, including:

[0054] An acquisition module for acquiring the set pressure value and the actual pressure data of the pressure sensor at the butterfly valve;

[0055] A processing module for comparing the set pressure value with the actual pressure data and calculating the current pressure deviation;

[0056] A calculation module for calculating the current pressure deviation by using the PID control algorithm;

[0057] A control module for determining the opening degree of the butterfly valve according to the control value output by the PID;

[0058] An adjustment module for controlling the electric actuator to adjust the corresponding butterfly valve according to the opening degree;

[0059] A first monitoring module for monitoring the position of the butterfly valve and the fluid pressure within the predicted time after adjustment;

[0060] An evaluation module for evaluating the accuracy of the PID control algorithm according to the position of the butterfly valve and the fluid pressure;

[0061] A determination module for determining the PID parameter adjustment strategy according to the evaluation result and controlling the electric actuator to adjust the corresponding butterfly valve;

[0062] A second monitoring module for monitoring the response speed of the butterfly valve and the pressure overshoot after response after the adjustment strategy;

[0063] A verification module for verifying the effectiveness of the PID parameter adjustment strategy according to the response speed and the pressure overshoot;

[0064] An adjustment module for optimizing the PID parameter adjustment strategy according to the verification result;

[0065] An analysis module for monitoring the butterfly valve pressure value after the PID parameter adjustment strategy is optimized, determining whether the butterfly valve pressure value reaches the set pressure value, and determining the correction measure according to the judgment result.

[0066] Compared with the prior art, the beneficial effects of the present invention are as follows: by obtaining the set pressure value and the actual pressure data, comparing and calculating the pressure deviation, calculating the control value using the PID control algorithm, determining the opening degree of the butterfly valve, and controlling the butterfly valve according to the opening degree, the adjustment and control of the position of the butterfly valve are realized, ensuring that the system can be stably controlled according to the preset pressure value. Then, the position of the butterfly valve and the fluid pressure are monitored to evaluate the accuracy of the PID control algorithm, and to find out whether there are problems such as changes in the position of the butterfly valve and control oscillations, providing a basis for further optimizing the PID parameter adjustment strategy. According to the evaluation results, the PID parameter adjustment strategy is determined. By checking the system response speed and overshoot, the effectiveness of the adjustment strategy is verified, and the PID parameters are further optimized according to the verification results to improve the control accuracy and stability of the system. Finally, the pressure value of the adjusted butterfly valve is monitored and the correction measures are determined according to the results, which are used to monitor the operating state of the system in real time, ensure that the pressure value of the butterfly valve can accurately reach the set value, and make corrections in time to ensure the normal operation of the system, ensure the accuracy of the measurement data and improve the accuracy of the intelligent control of the butterfly valve. Description of the Drawings

[0067] Figure 1 It is a schematic flow chart of the intelligent control method for the electric butterfly valve in this embodiment;

[0068] Figure 2 It is a schematic structural diagram of the intelligent control system for the electric butterfly valve in this embodiment. Detailed Embodiments

[0069] In order to make the purpose and advantages of the present invention clearer, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0070] The preferred embodiments of the present invention will be described below with reference to the drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0071] It should be noted that in the description of the present invention, the terms indicating the direction or positional relationship such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0072] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0073] Please refer to Figure 1 as shown, which is a schematic flowchart of the intelligent control method for the electric butterfly valve in this embodiment. This method is executed by an electronic device such as a computer or a server. The method includes:

[0074] Step S1, obtain the set pressure value and obtain the actual pressure data of the pressure sensor at the butterfly valve; a pressure sensor is provided at each butterfly valve.

[0075] Step S2, compare the set pressure value with the actual pressure data and calculate the current pressure deviation; current pressure deviation = actual pressure data - set pressure value.

[0076] Step S3, calculate the current pressure deviation using the PID control algorithm;

[0077] Step S4, determine the opening degree of the butterfly valve according to the control value output by the PID;

[0078] Step S5, control the electric actuator to adjust the corresponding butterfly valve according to the opening degree;

[0079] Step S6, monitor the position of the butterfly valve and the fluid pressure within the predicted time after adjustment; install a position sensor on the butterfly valve, and collect and read the real-time position data of the butterfly valve through the sensor. Common position sensors include travel switches, Hall sensors, etc.

[0080] Step S7, evaluate the accuracy of the PID control algorithm according to the position of the butterfly valve and the fluid pressure; incorrect PID calculation will cause the butterfly valve to oscillate, and then cause the position of the butterfly valve to change.

[0081] Step S8, determine the PID parameter adjustment strategy according to the evaluation result, and control the electric actuator to adjust the corresponding butterfly valve; the strategy is which parameter to adjust and how much to adjust. Calculate the control value of the butterfly valve again according to the adjusted parameter to determine the opening degree of the butterfly valve, and control and adjust the opening degree of the butterfly valve.

[0082] Step S9, monitor the response speed of the butterfly valve and the pressure overshoot after response after the adjustment strategy;

[0083] Step S10, verify the effectiveness of the PID parameter adjustment strategy according to the response speed and pressure overshoot;

[0084] Step S11, optimize the PID parameter adjustment strategy according to the verification result;

[0085] Step S12, monitor the butterfly valve pressure value after the optimization of the PID parameter adjustment strategy, and judge whether the butterfly valve pressure value reaches the set pressure value, and determine the correction measure according to the judgment result.

[0086] Specifically, by obtaining the set pressure value and the actual pressure data, comparing and calculating the pressure deviation, calculating the control value using the PID control algorithm, determining the opening degree of the butterfly valve, and controlling the butterfly valve according to the opening degree, the adjustment and control of the butterfly valve position are realized, ensuring that the system can be stably controlled according to the preset pressure value. Then monitor the butterfly valve position and fluid pressure, evaluate the accuracy of the PID control algorithm, and find out whether there are problems such as butterfly valve position change and control oscillation, providing a basis for further optimizing the PID parameter adjustment strategy. Determine the PID parameter adjustment strategy according to the evaluation result, verify the effectiveness of the adjustment strategy by checking the system response speed and overshoot, and further optimize the PID parameters according to the verification result to improve the control accuracy and stability of the system. Finally, monitor the adjusted butterfly valve pressure value and determine the correction measure according to the result, which is used to monitor the operation state of the system in real time, ensure that the butterfly valve pressure value can accurately reach the set value, and make corrections in time to ensure the normal operation of the butterfly valve system, ensure the accuracy of measurement data and improve the accuracy of intelligent control of the butterfly valve.

[0087] Specifically, in the step S3, when calculating the current pressure deviation E using the PID control algorithm, obtain the historical pressure deviation, sum the historical pressure deviation and the current pressure deviation to obtain the integral term I, calculate the differential term D according to the current pressure deviation and the previous pressure deviation, and calculate the proportional term P according to the preset proportional parameter and the current pressure deviation;

[0088] Calculate the control value according to the current pressure deviation E, the proportional term P, the integral term I and the differential term D, where the control value = P×E + I + D.

[0089] Specifically, the historical deviation is the pressure deviation value calculated before the current moment. The previous pressure deviation is the historical pressure deviation value closest to the current moment. The differential term D = the current pressure deviation - the previous pressure deviation, and the proportional term P = the preset proportional parameter × the current pressure deviation. By comprehensively considering the influences of the current pressure deviation, the historical pressure deviation, and the preset proportional parameter, through the calculation of the integral term I and the differential term D, the actual state and dynamic changes of the system can be more accurately reflected. Through the comprehensive calculation of the proportional term P, the integral term I, and the differential term D, the control value of the system can be effectively adjusted to achieve precise adjustment of the butterfly valve position.

[0090] Specifically, in the step S4, when determining the opening degree of the butterfly valve according to the control value output by the PID, judge the positive and negative of the control value A, where:

[0091] If A > 0, it is determined to increase the opening degree of the butterfly valve;

[0092] If A < 0, it is determined to decrease the opening degree of the butterfly valve;

[0093] If A = 0, it is determined that the opening degree of the butterfly valve does not need to be adjusted.

[0094] Specifically, by judging the positive and negative of the control value, the opening degree of the butterfly valve can be adjusted in real time according to the actual state of the system, and the position of the butterfly valve can be adjusted according to the magnitude of the control value to effectively adjust the system pressure, ensuring that the system can respond quickly and be stably controlled. When the control value is positive, it means that the current pressure deviation requires increasing the opening degree of the butterfly valve to increase the output pressure of the system; when the control value is negative, it means that the opening degree of the butterfly valve needs to be decreased to reduce the system output pressure; when the control value is zero, it means that although a pressure deviation occurs, the opening degree of the butterfly valve does not need to be adjusted. By adjusting the opening degree of the butterfly valve according to the control value output by the PID, the on-line automatic adjustment of the control system can be realized, improving the control accuracy and stability of the system, and ensuring that the system is accurately controlled according to the preset pressure value.

[0095] Specifically, in the step S7, when evaluating the accuracy of the PID control algorithm, calculate the standard deviation P of the butterfly valve position and the standard deviation Q of the fluid pressure within a preset time respectively, and compare the standard deviation of the butterfly valve position and the standard deviation of the fluid pressure with the standard deviation threshold P0 of the butterfly valve position and the standard deviation threshold Q0 of the fluid pressure respectively to determine whether the butterfly valve position and the fluid pressure are abnormal, where,

[0096] If P > P0, it is determined that the butterfly valve position fluctuates frequently;

[0097] If P ≤ P0, it is determined that the butterfly valve position is normal;

[0098] If Q > Q0, it is determined that the fluid pressure fluctuates greatly;

[0099] If Q > Q0, it is determined that the fluid pressure is normal;

[0100] Evaluate the accuracy of the PID control algorithm based on the abnormal conditions of the butterfly valve position and the fluid pressure, where,

[0101] If both the butterfly valve position and the fluid pressure are normal, it is determined that the PID control algorithm is normal;

[0102] If the butterfly valve position fluctuates frequently and the fluid pressure fluctuates greatly, it is determined that the PID control algorithm is inaccurate;

[0103] If the butterfly valve position fluctuates frequently and the fluid pressure is normal, it is determined that the PID control algorithm is inaccurate;

[0104] If the butterfly valve position is normal and the fluid pressure fluctuates greatly, it is determined that the fluid state is abnormal, and the temperature and density of the fluid in the pipeline are detected.

[0105] Specifically, the standard deviation of the butterfly valve position is calculated based on the three-dimensional coordinate data collected within a certain period of time, including the data points in the X, Y, and Z directions. Calculate the average values of the coordinate data in the X, Y, and Z directions respectively, that is, add up all the data points and then divide by the number of data points to obtain the average value of the X coordinate, the average value of the Y coordinate, and the average value of the Z coordinate. Calculate the difference between each data point and the average value, and perform this step for the data in the X, Y, and Z directions respectively to obtain the differences in the X direction, the Y direction, and the Z direction. Square and sum the differences in each direction to obtain the total sum of squares. Divide the total sum of squares by the number of data points and then take the square root of the result to obtain the standard deviation of the three-dimensional coordinate data points. By calculating and comparing the standard deviation of the butterfly valve position and the standard deviation of the fluid pressure, abnormal conditions such as frequent fluctuations in the butterfly valve position or large fluctuations in the fluid pressure can be detected in a timely manner, thereby judging the stability and accuracy of the butterfly valve system, improving the reliability and stability of controlling the butterfly valve. When evaluating the accuracy of the PID control algorithm, it is determined based on the abnormal conditions of the butterfly valve position and the fluid pressure, and possible system problems can be detected in a timely manner. When the evaluation results show that the butterfly valve position fluctuates frequently and the fluid pressure fluctuates greatly, it can be determined that the PID control algorithm is inaccurate, or possible fault causes can be detected and repaired to ensure the normal operation and accurate control of the butterfly valve control system.

[0106] Specifically, in step S8, when determining the PID parameter adjustment strategy, the adjustment strategy is determined based on the factors when the PID control algorithm is inaccurate, where:

[0107] If the control value A output by the PID is 0, increase the actual differential term, set the adjustment coefficient v1, set 0.1 ≤ v1 ≤ 0.2, and the adjusted differential term Dv0 = D + v1 × D;

[0108] If the position of the butterfly valve fluctuates frequently and the fluid pressure fluctuates significantly, increase the actual integral term, set the adjustment coefficient v2, where 0.1 ≤ v2 ≤ 0.5, and the adjusted integral term Iv0 = I + v2 × I;

[0109] If the position of the butterfly valve fluctuates frequently and the fluid pressure is normal, increase the actual proportional term, set the adjustment coefficient v3, where 0.1 ≤ v3 ≤ 0.5, and the adjusted proportional term Pv0 = P + v3 × P.

[0110] Specifically, by increasing the actual differential term, actual integral term or actual proportional term and setting the adjustment coefficient, the PID parameters can be effectively adjusted, the control algorithm can be optimized according to the actual situation, thereby improving the system's response ability to dynamic changes, reducing the system's fluctuations and errors, enhancing the robustness and adaptability of the control system, and achieving the accuracy of the algorithm by increasing the weights of the differential term, integral term or proportional term, providing effective support and guarantee for the precise control of the butterfly valve.

[0111] Specifically, in step S10, when verifying the effectiveness of the PID parameter adjustment strategy, compare the response speed X and the pressure overshoot Y with the response speed threshold X0 and the pressure overshoot threshold Y0 respectively, where:

[0112] If X < X0, it is determined that the response speed of the butterfly valve is too slow;

[0113] If X ≥ X0, it is determined that the response speed of the butterfly valve is normal;

[0114] If Y > Y0, it is determined that the pressure overshoot of the butterfly valve is too large;

[0115] If Y ≤ Y0, it is determined that the pressure overshoot of the butterfly valve is normal;

[0116] Verify the effectiveness of the PID parameter adjustment strategy according to the abnormal conditions of the response speed and pressure overshoot of the butterfly valve, where:

[0117] If both the response speed and the pressure overshoot are normal, it is verified that the PID parameter adjustment strategy is effective;

[0118] If the response speed is too slow and the pressure overshoot is too large, it is determined that environmental factors cause the response speed to be too slow and the pressure overshoot to be too large, and check whether the electric actuator is damaged;

[0119] If the response speed is too slow and the pressure overshoot is normal, it is verified that the PID parameter adjustment strategy is invalid;

[0120] If the response speed is normal and the pressure overshoot is too large, it is verified that the PID parameter adjustment strategy is invalid.

[0121] Specifically, by comparing and determining the response speed and pressure overshoot of the butterfly valve, problems that may exist in the control process of the butterfly valve can be detected in a timely manner, such as problems like too slow response speed or too large pressure overshoot. By analyzing the response speed and pressure overshoot problems, the effectiveness of the PID parameter adjustment strategy can be accurately judged, and then optimized in a timely manner to reduce mistakes.

[0122] Specifically, in the step S11, when optimizing the PID parameter adjustment strategy, it is optimized according to the invalid result of the PID parameter adjustment strategy, where:

[0123] If the response speed is too slow and the pressure overshoot is normal, then expand the adjustment coefficient v3;

[0124] If the response speed is normal and the pressure overshoot is too large, then reduce the adjustment coefficient v3.

[0125] Specifically, if the response speed is too slow, it indicates that the system reacts sluggishly, and it is necessary to increase the proportional term P to improve the sensitivity of the system, or adjust the integral term I to accelerate the correction speed of the system to the continuous error. If the overshoot is too large, it means that the butterfly valve has over-adjusted during the response process, and it is necessary to reduce the proportional term P or adjust the integral term I to reduce the impact of over-adjustment, or increase the derivative term D to suppress the oscillation phenomenon of the system. When expanding or reducing, it can be continuously optimized according to a certain multiple. By further optimizing the PID parameter adjustment strategy, the PID parameters can be effectively adjusted, the response speed and stability of the system can be improved, the overshoot and error of the butterfly valve system can be reduced, thereby improving the control performance of the butterfly valve system.

[0126] Specifically, in the step S12, when monitoring the pressure value of the butterfly valve after optimizing the PID parameter adjustment strategy and judging whether the pressure value of the butterfly valve reaches the set pressure value, the pressure value of the butterfly valve is compared with the set pressure value. If the pressure value of the butterfly valve does not reach the set pressure value, it is judged that the environmental factors of the butterfly valve are abnormal.

[0127] Specifically, after optimizing and adjusting the parameters of the PID algorithm multiple times, if the pressure value of the butterfly valve still does not reach the set pressure value, it is necessary to judge that the environmental factors of the butterfly valve are abnormal to ensure the normal operation and stability of the butterfly valve system.

[0128] Specifically, when determining the correction measure according to the judgment result, if the environmental factors of the butterfly valve are abnormal, then detect the temperature and density of the fluid and whether the detection sensor is faulty.

[0129] Specifically, by detecting the temperature and density of the fluid and whether the sensor is faulty, it is possible to rule out the possibility of abnormal butterfly valve pressure caused by environmental factors in the system, and further determine whether there is a sensor fault or other problems in the system. This helps to detect and solve system faults in a timely manner, ensure the normal operation of the system, avoid incorrect judgments and operations caused by sensor faults or inaccurate data, rule out possibilities such as abnormal environmental factors and sensor faults, and can promptly identify and correct problems in the system, which is beneficial to improving the stability and reliability of the system, reducing the likelihood of faults occurring, ensuring the normal operation of the system under various working conditions, guaranteeing the accuracy of measurement data, and improving the accuracy of intelligent control of the butterfly valve.

[0130] Please refer to Figure 2 shown in the figure, which is a schematic structural diagram of the intelligent control system of the electric butterfly valve in this embodiment. The system includes:

[0131] An acquisition module for acquiring a set pressure value and the actual pressure data of the pressure sensor at the butterfly valve.

[0132] A processing module for comparing the set pressure value with the actual pressure data and calculating the current pressure deviation.

[0133] A calculation module for calculating the current pressure deviation using the PID control algorithm.

[0134] A control module for determining the opening degree of the butterfly valve according to the control value output by the PID.

[0135] An adjustment module for controlling the electric actuator to adjust the corresponding butterfly valve according to the opening degree.

[0136] A first monitoring module for monitoring the position of the butterfly valve and the fluid pressure within the predicted time after adjustment.

[0137] An evaluation module for evaluating the accuracy of the PID control algorithm according to the position of the butterfly valve and the fluid pressure.

[0138] A determination module for determining the PID parameter adjustment strategy according to the evaluation result and controlling the electric actuator to adjust the corresponding butterfly valve.

[0139] A second monitoring module for monitoring the response speed of the butterfly valve and the pressure overshoot after response after the adjustment strategy.

[0140] A verification module for verifying the effectiveness of the PID parameter adjustment strategy according to the response speed and the pressure overshoot.

[0141] An adjustment module for optimizing the PID parameter adjustment strategy according to the verification result.

[0142] An analysis module is used to monitor the pressure value of the butterfly valve after the PID parameter adjustment strategy is optimized, and determine whether the butterfly valve pressure value reaches the set pressure value, and determine the correction measures according to the judgment result.

[0143] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. An intelligent control method for an electric butterfly valve, characterized in that: include: Step S1, obtaining a set pressure value and obtaining actual pressure data of a pressure sensor at a butterfly valve; Step S2, comparing the set pressure value with the actual pressure data, and calculating the current pressure deviation; Step S3, calculating the current pressure deviation using a PID control algorithm; Step S4, determining the opening degree of the butterfly valve according to the control value output by the PID; Step S5, controlling the electric actuator to adjust the corresponding butterfly valve according to the opening degree; Step S6, monitoring the butterfly valve position and fluid pressure within the adjusted predicted time; Step S7, evaluating the accuracy of the PID control algorithm according to the butterfly valve position and the fluid pressure; Step S8, determining a PID parameter adjustment strategy according to the evaluation result, and controlling the electric actuator to adjust the corresponding butterfly valve; Step S9, monitoring the response speed of the butterfly valve after the adjustment strategy and the pressure overshoot after the response; Step S10, verifying the effectiveness of the PID parameter adjustment strategy according to the response speed and the pressure overshoot; Step S11, optimizing the PID parameter adjustment strategy according to the verification result; Step S12, monitoring the butterfly valve pressure value after the PID parameter adjustment strategy is optimized, and judging whether the butterfly valve pressure value reaches the set pressure value, and determining the correction measures according to the judgment result; In step S7, when evaluating the accuracy of the PID control algorithm, the standard deviation P of the butterfly valve position and the standard deviation Q of the fluid pressure within the preset time are calculated respectively, and the standard deviation of the butterfly valve position and the standard deviation of the fluid pressure are compared with the standard deviation threshold P0 of the butterfly valve position and the standard deviation threshold Q0 of the fluid pressure respectively to determine whether the butterfly valve position and the fluid pressure are abnormal, wherein, If P>P0, it is determined that the position of the butterfly valve fluctuates frequently; If P≤P0, it is determined that the position of the butterfly valve is normal; If Q>Q0, it is determined that the fluid pressure fluctuates greatly; If Q>Q0, it is determined that the fluid pressure is normal; The accuracy of the PID control algorithm is evaluated based on the abnormal conditions of the butterfly valve position and fluid pressure, wherein: If the butterfly valve position and the fluid pressure are both normal, it is determined that the PID control algorithm is normal; If the butterfly valve position fluctuates frequently and the fluid pressure fluctuates greatly, it is determined that the PID control algorithm is inaccurate; If the butterfly valve position fluctuates frequently and the fluid pressure is normal, it is determined that the PID control algorithm is inaccurate; If the butterfly valve is in a normal position and the fluid pressure fluctuates greatly, the fluid state is determined to be abnormal, and the temperature and density of the fluid in the pipeline are detected; In step S8, when determining the PID parameter adjustment strategy, the adjustment strategy is determined according to factors when the PID control algorithm is inaccurate, wherein: If the control value A of the PID output is 0, the actual differential term is increased, and the adjustment coefficient v1 is set to 0.1≤v1≤0.2, and the adjusted differential term Dv0=D+v1×D; If the butterfly valve position fluctuates frequently and the fluid pressure fluctuates greatly, the actual integral term is increased, and the adjustment coefficient v2 is set, and 0.1≤v2≤0.5 is set, and the adjusted integral term Iv0=I+v2×I; If the butterfly valve position fluctuates frequently and the fluid pressure is normal, the actual proportional term is increased, and the adjustment coefficient v3 is set, and 0.1≤v3≤0.5 is set, and the adjusted proportional term Pv0=P+v3×P; In step S10, when verifying the effectiveness of the PID parameter adjustment strategy, the response speed X and the pressure overshoot Y are compared with the response speed threshold X0 and the pressure overshoot threshold Y0 respectively, where: If X<X0, it is determined that the response speed of the butterfly valve is too slow; If X≥X0, the response speed of the butterfly valve is determined to be normal; If Y>Y0, it is determined that the pressure overshoot of the butterfly valve is too large; If Y≤Y0, it is determined that the pressure overshoot of the butterfly valve is normal; The effectiveness of the PID parameter adjustment strategy is verified based on the abnormal conditions of the butterfly valve's response speed and pressure overshoot, where: If the response speed and pressure overshoot are normal, the PID parameter adjustment strategy is verified to be effective; If the response speed is too slow and the pressure overshoot is too large, it is determined that environmental factors cause the response speed to be too slow and the pressure overshoot to be too large, and the electric actuator is detected to be damaged; If the response speed is too slow and the pressure overshoot is normal, then the PID parameter adjustment strategy is invalid; If the response speed is normal and the pressure overshoot is too large, then the PID parameter adjustment strategy is invalid; In the step S11, when optimizing the PID parameter adjustment strategy, the optimization is performed according to the invalid result of the PID parameter adjustment strategy, wherein: If the response speed is too slow and the pressure overshoot is normal, the adjustment coefficient v3 is increased; If the response speed is normal and the pressure overshoot is too large, the adjustment coefficient v3 is reduced.

2. The intelligent control method of an electric butterfly valve according to claim 1 is characterized in that: In step S3, when the current pressure deviation E is calculated using the PID control algorithm, the historical pressure deviation is obtained, the historical pressure deviation and the current pressure deviation are summed to obtain the integral term I, the differential term D is calculated according to the current pressure deviation and the previous pressure deviation, and the proportional term P is calculated according to the preset proportional parameter and the current pressure deviation; A control value is calculated according to the current pressure deviation E, the proportional term P, the integral term I and the differential term D, wherein control value=P×E+I+D.

3. The intelligent control method of an electric butterfly valve according to claim 1 is characterized in that: In step S4, when determining the opening degree of the butterfly valve according to the control value output by the PID, the positive or negative of the control value A is determined, where: If A>0, it is determined to increase the opening degree of the butterfly valve; If A<0, it is determined to reduce the opening degree of the butterfly valve; If A=0, it is determined that there is no need to adjust the opening degree of the butterfly valve.

4. The intelligent control method of an electric butterfly valve according to claim 1 is characterized in that: In step S12, when monitoring the butterfly valve pressure value after the PID parameter adjustment strategy is optimized and determining whether the butterfly valve pressure value reaches the set pressure value, the butterfly valve pressure value is compared with the set pressure value. If the butterfly valve pressure value does not reach the set pressure value, it is determined that the environmental factors of the butterfly valve are abnormal.

5. The intelligent control method of an electric butterfly valve according to claim 1 is characterized in that: When determining the corrective measures based on the judgment results, if the environmental factors of the butterfly valve are abnormal, the temperature and density of the fluid are detected and whether the sensor is faulty.

6. A system applied to the intelligent control method of the electric butterfly valve according to any one of claims 1 to 5, characterized in that: include: An acquisition module is used to obtain a set pressure value and obtain actual pressure data of a pressure sensor at a butterfly valve; A processing module, used for comparing the set pressure value with the actual pressure data, and calculating a current pressure deviation; A calculation module, used to calculate the current pressure deviation using a PID control algorithm; A control module, used to determine the opening degree of the butterfly valve according to the control value output by the PID; A regulating module, used for controlling the electric actuator to regulate the corresponding butterfly valve according to the opening degree; A first monitoring module, used to monitor the butterfly valve position and fluid pressure within the adjusted predicted time; An evaluation module, for evaluating the accuracy of a PID control algorithm based on the butterfly valve position and the fluid pressure; A determination module is used to determine a PID parameter adjustment strategy according to the evaluation result, and control the electric actuator to adjust the corresponding butterfly valve; The second monitoring module is used to monitor the response speed of the butterfly valve after the adjustment strategy and the pressure overshoot after the response; A verification module, used to verify the effectiveness of the PID parameter adjustment strategy according to the response speed and the pressure overshoot; An adjustment module is used to optimize the PID parameter adjustment strategy according to the verification results; The analysis module is used to monitor the butterfly valve pressure value after the PID parameter adjustment strategy is optimized, and to determine whether the butterfly valve pressure value reaches the set pressure value, and to determine the corrective measures based on the judgment result.

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