A method for integrated control of a three-redundant configuration of a gas turbine compressor variable guide vane based on an electric cylinder

Abstract

This invention discloses an integrated control method for a three-redundant configuration of rotatable guide vanes in a gas turbine compressor based on an electric cylinder, relating to the field of gas turbine technology. The method includes the following specific steps: performing zero-point self-check and on-site calibration of the angular displacement sensor and establishing a multi-source mapping relationship; using the angular displacement sensor feedback as a feedback source to enter closed-loop control and recording multi-source data association; fusing each test result for comprehensive decision-making to obtain a positioning conclusion; and taking over control based on the electric cylinder's own feedback closed-loop control. This invention establishes a multi-source feedback and control path including direct feedback from the angular displacement sensor, electric cylinder stroke conversion feedback, and pressure-angle mapping calibration. It breaks the complete dependence of traditional control methods on a single feedback loop and overcomes the shortcomings of traditional schemes that can only identify fault occurrences but cannot locate the fault location, providing a clear judgment basis for unit operation and maintenance.

Description

Technical Field

[0001] This invention relates to the field of gas turbine technology, specifically to an integrated control method for a three-redundant configuration of rotatable guide vanes in a gas turbine compressor based on an electric cylinder. Background Technology

[0002] Modern gas turbines mostly use electric cylinders to drive the rotatable guide vanes of the compressor, converting the linear reciprocating motion of the electric cylinder into the back-and-forth rotation of the guide vanes. In the control process of the electric cylinder, the operating status is typically determined by comparing the control command with its own feedback, and displacement adjustment is made in the next control cycle, forming a closed-loop control. The advantage of this control method is its simplicity and ease of use; the disadvantage is its reliance on the normal operation of the electric cylinder. When the electric cylinder experiences a feedback fault or failure, the rotatable guide vane control system will malfunction, posing a significant safety hazard to the gas turbine. Especially under conditions of high speed, high temperature, and variable load in gas turbines, electric cylinder failure can restrict its operating state, causing sudden changes in the gas turbine's thermodynamic parameters, and in severe cases, leading to instability or damage to the gas turbine. Therefore, redundant control of the electric cylinder is essential to ensure the safe operation of the gas turbine. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides an integrated control method for a three-redundant configuration of rotatable guide vanes in a gas turbine compressor based on an electric cylinder, comprising the following specific steps: S1. After the gas turbine control system and electric cylinder control system are initialized, perform zero-point self-test and dial field verification of the angular displacement sensor to establish a multi-source mapping relationship. S2. The gas turbine is started and put into operation. Based on the feedback from the angular displacement sensor, it enters closed-loop control and records multi-source data. S3. Based on the multi-source dynamic synchronous data record set obtained from the multi-source data association record, the analysis object is used to perform tests including the static deviation of the angular displacement sensor exceeding the limit, the quantification of the motion correlation of the transmission chain, and the consistency test of the motion trend. The results of each test are integrated to make a comprehensive decision and obtain the positioning conclusion. S4. Extract and lock the working reference point of the electric cylinder at the moment before the fault based on the positioning conclusion, form a data pair of electric cylinder stroke-angle reference points at the moment before the fault, and correct the multi-source mapping relationship and zero and full position online, and take over the control based on the feedback of the electric cylinder itself.

[0004] Preferably, step S1 retrieves test data based on the gas turbine whole-machine test and / or historical operation database. For newly developed units, a gas turbine whole-machine test is required; for older units, valid test data is retrieved from their historical operation database. This data spans the entire operating range of the gas turbine, from ignition and idle to full load, and at equal intervals or according to preset equivalent speed intervals. Several sets of steady-state operating point data, including compressor equivalent speed values ​​and high-pressure air pressure values, are collected. Using compressor equivalent speed as the independent variable and high-pressure air pressure as the dependent variable, the collected discrete steady-state operating point data are analyzed using a nonlinear least squares curve fitting method. Through iterative adaptive adjustment between gradient descent and Gauss-Newton methods, the optimal parameter set that minimizes the sum of squared errors between the predicted and measured pressure values ​​at each point on the fitted curve is obtained. This generates a coefficient combination to describe the corresponding power function curve, forming a set of power function mapping relationships between high-pressure air pressure and compressor equivalent speed.

[0005] Preferably, step S1 is based on a pre-defined design law between the rotatable guide vane angle and the compressor's equivalent speed, which is determined according to surge margin and overall machine performance requirements. Within the working stroke range of the electric cylinder, this law is explicitly defined as a linear binding relationship. The compressor's equivalent speed, which has a linear relationship, is used as a transfer variable, and variable substitution is performed using a power function mapping relationship between the high-pressure air pressure and the compressor's equivalent speed. Specifically, for each equivalent speed value within the compressor's working range, the corresponding rotatable guide vane angle value is first indexed in the aforementioned linear relationship, and then the corresponding high-pressure air pressure value is indexed in the power function relationship, thus obtaining a new data pair, i.e., a one-to-one correspondence between the high-pressure air pressure value and the rotatable guide vane angle value. Please refer to the appendix. Figure 5 The discrete mapping point set composed of pressure-angle data pairs is obtained, and the discrete mapping point set is fitted into a continuous curve based on the polynomial least squares fitting method of singular value decomposition. The singular value decomposition algorithm used in this application can robustly solve the optimal solution of each coefficient of the polynomial by decomposing the coefficient matrix into a set of orthogonal bases. Even when there is weak noise in the data, the numerical stability of the fitting can be guaranteed. The coefficients of each order of the polynomial of the generated continuous curve form a set of parabolic mapping relationships between high-pressure air pressure and rotatable guide vane angle with the domain. Based on the gas turbine shutdown state, the electric cylinder control system calibrates the mechanical zero position by recording the stroke endpoint and obtains the linear conversion coefficient through the geometric transmission relationship of the rigid connection between the rotatable guide vane linkage ring and the electric cylinder push rod. That is, the change in the corresponding angle of rotation of the rotatable guide vane linkage ring for each unit length extended by the electric cylinder push rod. Since the change in the corresponding angle of rotation of the rotatable guide vane linkage ring is constant, in order to correct manufacturing and installation errors, the control system drives the electric cylinder push rod to perform a slow, uniform scanning motion of the entire stroke, and simultaneously records the precise angle value fed back by the angular displacement sensor and the push rod stroke value fed back by the electric cylinder itself at a high sampling rate. Based on the stroke-angle data, the slope and intercept parameters of the linear relationship between the rotatable guide vane linkage ring and the electric cylinder push rod are obtained through a regression algorithm, forming a set of linear mapping relationships between the electric cylinder stroke and the rotatable guide vane angle.

[0006] Preferably, S2 collects the total temperature value of the inlet airflow measured by the total temperature sensor installed at the compressor inlet and the physical speed value of the compressor measured by the speed sensor installed on the rotor in real time based on the control cycle of the gas turbine control system. Based on the preset target value calculation function for the rotatable guide vane angle, bilinear interpolation is used to calculate the rotatable guide vane angle value corresponding to the current total temperature and the current speed, and this value is used as the target command for the rotatable guide vane angle.

[0007] Preferably, S2 sends the generated target angle command of the rotatable guide vane to the electric cylinder control system via fieldbus and drives the push rod to perform linear reciprocating motion via the drive servo motor and reduction mechanism, and changes the rotation angle of the rotatable guide vane through the rotatable guide vane linkage ring. Based on the angular displacement sensor installed on the rotatable guide vane linkage, the actual physical rotation angle of the rotatable guide vane is detected at the same control frequency and sent back to the gas turbine control system as the real-time feedback value of the angular displacement sensor. The deviation between the real-time feedback value of the angular displacement sensor and the target angle command of the rotatable guide vane is calculated. The current deviation is amplified by PID to obtain a fast adjustment command proportional to the magnitude of the deviation. The integral term accumulates the deviation over time to eliminate the small steady-state error that has existed for a long time and ensure that there is no steady-state error. The derivative term calculates the rate of change of the deviation, predicts the trend of the deviation in advance, and generates a damping command to suppress the overshoot and oscillation of the system. After the three commands are combined, the final electric cylinder position fine-tuning command is formed. Based on the drive actuator moving in the direction of reducing the deviation, the closed-loop control is completed. Finally, the deviation between the real-time feedback value of the angular displacement sensor and the target angle command of the rotatable guide vane is continuously and stably controlled within the accuracy range of ±0.5 degrees. During the closed-loop control, at the end of each control cycle, S2 performs data packaging and storage operations. Specifically, it timestamps the generated rotatable guide vane angle target command, the real-time feedback value of the angular displacement sensor, and the electric cylinder push rod stroke feedback value measured by the electric cylinder internal displacement sensor, which is simultaneously obtained from the communication with the electric cylinder control system. These data are then sequentially stored in a fixed-capacity, first-in-first-out circular buffer storage area, forming a multi-source dynamic synchronous data record set. This application records the relationship between the target and the response through the data record set and also establishes a real-time correspondence between the physical displacement of the execution end and the angle expectation of the control end.

[0008] Preferably, S3 extracts all associated data groups within the most recent complete time window based on the multi-source dynamic synchronous data record set in the circular buffer storage area, and extracts the rotatable guide vane angle target command and the real-time feedback value of the angular displacement sensor based on each data group within the time window. After calculating the absolute value of the difference, it is compared with a preset fault judgment threshold. In order to avoid false alarms caused by random noise or instantaneous disturbances, the process adopts a continuous counting mechanism, that is, continuously monitors the difference. Only when the absolute value of the difference exceeds the threshold for a cumulative number of control cycles within the time window reaches a preset count value, such as 20 consecutive cycles, does the process generate a primary event marker indicating that the angular displacement sensor deviation exceeds the limit. Then, based on the multi-source dynamic synchronous data record set in the circular buffer storage area, the time series composed of real-time feedback values ​​of angular displacement sensors and time series composed of electric cylinder push rod stroke feedback values ​​are extracted. Through Pearson correlation coefficient calculation, a primary event marker for abnormal mechanical transmission chain motion is generated.

[0009] Preferably, step S2 calculates the difference between the current value and the previous value of the target command sequence for the rotatable guide vane angle and the feedback value sequence for the electric cylinder push rod stroke, based on the multi-source dynamic synchronous data recording set. The mathematical symbols of these differences are extracted to form the desired motion direction sequence and the actual motion direction sequence of the actuator. A positive sign represents an increase in the desired angle, and a negative sign represents a decrease. The desired motion direction sequence and the actual motion direction sequence are compared point-by-point for consistency. If multiple consecutive moments show a positive desired motion direction and a negative actual motion direction, or vice versa, a logical contradiction is constituted. This contradiction clearly indicates that the electric cylinder servo system has failed to respond correctly to the control command, and the fault may be located in the electric cylinder's servo driver, motor, or its own displacement feedback loop. When the cumulative number of such logical contradiction events within the time window exceeds a preset threshold, a primary event marker indicating abnormal feedback response of the electric cylinder and / or its own system is generated. Based on the primary event flags indicating abnormal electric cylinder and / or self-feedback response, the primary event flag indicating excessive angular displacement sensor deviation, and the primary event flag indicating excessive angular displacement sensor deviation, logical operations are performed to complete a comprehensive decision and form a location conclusion. Specifically, in case one, the comprehensive decision logic will output a final judgment conclusion: the fault source is the angular displacement sensor itself, only if the primary event flag indicating excessive angular displacement sensor deviation is true, and both the primary event flag indicating abnormal mechanical transmission chain movement and the primary event flag indicating abnormal electric cylinder or self-feedback response are false. In case two, if both the excessive deviation and abnormal movement flags are true, the fault source is determined to be the mechanical transmission chain such as the rotatable guide vane linkage ring. In case three, if both the excessive deviation and abnormal response flags are true, the fault source is determined to be the electric cylinder actuator assembly.

[0010] Preferably, step S4 sends any adjustment command based on feedback from the angular displacement sensor to the electric cylinder based on the positioning conclusion, records the moment the positioning conclusion is generated, performs data retrieval from the multi-source dynamic synchronous data record set, searches for the associated data group of the last effective control cycle whose timestamp is earlier than the moment the positioning conclusion is generated, and extracts the corresponding rotatable guide vane angle target command and electric cylinder push rod stroke feedback value to form real working point data representing the instant before the fault occurred when the system was still in a high-precision synchronous state, as the electric cylinder stroke-angle reference point data pair at the instant before the fault.

[0011] Preferably, in step S4, the extracted reference point data pairs are used as constraints. Centered on the reference point, the intercept parameter of the linear mapping relationship line is used as the variable to be optimized. Based on the stroke value in the reference point, the angle value obtained by adjusting the new linear relationship after the intercept is completely equal to the angle measured by the angular displacement sensor in the reference point. The solution process is to substitute the stroke value of the reference point into the linear relationship expression containing the undetermined intercept, make its output equal to the angle value of the reference point, and directly solve for the specific value of the undetermined intercept. This newly solved intercept value represents the latest zero position offset of the electric cylinder. The latest zero position offset of the electric cylinder is obtained by solving, and the new intercept replaces the original intercept value in the linear mapping relationship set of electric cylinder stroke-rotatable guide vane angle, thus completing the online reset and correction of the mapping relationship set.

[0012] Preferably, after successfully updating the mapping relationship set, S4 inputs the real-time electric cylinder push rod stroke feedback value through communication to the modified electric cylinder stroke-rotatable guide vane angle linear mapping relationship set for conversion, obtains the equivalent feedback value of the rotatable guide vane angle, compares the equivalent feedback value of the rotatable guide vane angle with the target command of the rotatable guide vane angle, calculates the deviation, and forms a closed-loop adjustment through a proportional-integral-derivative controller.

[0013] Because the initial mapping relationship's zero point has been precisely corrected to the true state before the fault, the equivalent angle feedback value calculated based on the electric cylinder's current stroke at the moment of switching is highly consistent with the control target command at that time, without generating additional control deviations, thus achieving a smooth and disturbance-free control transition. Subsequently, the control system continues to operate in this backup closed-loop mode, maintaining the adjustment accuracy within the new allowable deviation range (e.g., ±1 degree), and finally enters a highly reliable electric cylinder self-feedback closed-loop control state. This state ensures that the gas turbine can still operate safely and stably after the angular displacement sensor fails.

[0014] Beneficial effects This invention provides an integrated control method for a three-redundant configuration of rotatable guide vanes in a gas turbine compressor based on an electric cylinder. It offers the following advantages: It establishes a multi-source feedback and control path, including direct feedback from an angular displacement sensor, electric cylinder stroke conversion feedback, and pressure-angle mapping verification. This breaks the traditional control method's complete reliance on a single feedback loop. When the main feedback channel fails, the control system can automatically switch to a redundant closed-loop loop, continuously maintaining the normal adjustment function of the rotatable guide vanes and preventing the overall control system from paralyzing due to feedback failure. Furthermore, combined with logical combination operations, it can clearly distinguish three different levels of faults: angular displacement sensor body faults, mechanical transmission link faults, and electric cylinder actuator assembly faults. This overcomes the shortcomings of traditional solutions that can only identify fault occurrences but cannot locate the fault location, providing a clear basis for judgment in unit operation and maintenance. Extract the stroke-angle reference data instant before the fault occurs, and use it as a constraint to correct the mapping relationship between the electric cylinder stroke and the guide vane rotation angle and the zero position offset online, so as to ensure that the equivalent feedback value at the moment of control loop switching matches the current control target. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the process of the present invention; Figure 2 This is a curve showing the relationship between the rotation angle of the rotatable guide vane and the compressor speed in this invention; Figure 3 This is a three-dimensional assembly drawing of the rotatable guide vane linkage ring, electric cylinder, and angular displacement sensor in this invention; Figure 4 This is the curve showing the relationship between the high-pressure air pressure and the compressor speed in this invention; Figure 5 This is the curve showing the relationship between the rotation angle of the rotatable guide vane and the air pressure after high pressure in this invention; Figure 6 This is a flowchart of the self-test and calibration procedure for the electric cylinder before starting a gas turbine based on an angular displacement sensor, according to the present invention. Figure 7The present invention is based on an integrated control program block diagram for a gas turbine compressor with a three-redundant configuration of rotatable guide vane angles using an electric cylinder. Detailed Implementation

[0016] The present invention will now be further described with reference to the accompanying drawings.

[0017] Please see Figure 1-7 This invention provides an integrated control method for a three-redundant configuration of rotatable guide vanes in a gas turbine compressor based on an electric cylinder, comprising the following steps: S1. After the gas turbine control system and electric cylinder control system are initialized, perform zero-point self-test and dial field verification of the angular displacement sensor to establish a multi-source mapping relationship. S2. The gas turbine is started and put into operation. Based on the feedback from the angular displacement sensor, it enters closed-loop control and records multi-source data. S3. Based on the multi-source dynamic synchronous data record set obtained from the multi-source data association record, the analysis object is used to perform tests including the static deviation of the angular displacement sensor exceeding the limit, the quantification of the motion correlation of the transmission chain, and the consistency test of the motion trend. The results of each test are integrated to make a comprehensive decision and obtain the positioning conclusion. S4. Extract and lock the working reference point of the electric cylinder at the moment before the fault based on the positioning conclusion, form a data pair of electric cylinder stroke-angle reference points at the moment before the fault, and correct the multi-source mapping relationship and zero and full position online, and take over the control based on the feedback of the electric cylinder itself.

[0018] S1 retrieves test data from the gas turbine whole-machine test and / or historical operation database. For newly developed units, a gas turbine whole-machine test is required; for older units, valid test data is retrieved from their historical operation database. This data spans the entire operating range of the gas turbine, from ignition and idle to full load, and is collected at equal intervals or according to preset equivalent speed intervals. Several sets of steady-state operating point data, including compressor equivalent speed values ​​and high-pressure air pressure values, are collected. Using compressor equivalent speed as the independent variable and high-pressure air pressure as the dependent variable, the collected discrete steady-state operating point data are analyzed using a nonlinear least squares curve fitting method. Through iterative adaptive adjustment between gradient descent and Gauss-Newton methods, the optimal parameter set that minimizes the sum of squared errors between the predicted and measured pressure values ​​at each point on the fitted curve is obtained. This generates a coefficient combination to describe the corresponding power function curve, forming a set of power function mapping relationships between high-pressure air pressure and compressor equivalent speed. Please refer to [reference needed]. Figure 4 As shown.

[0019] The S1 design rule, based on the surge margin and overall machine performance requirements, pre-determines the relationship between the rotatable guide vane angle and the compressor's equivalent speed. Within the working stroke range of the electric cylinder, this rule is explicitly defined as a linear binding relationship. The compressor's equivalent speed, which has a linear relationship, is used as a transfer variable, and a power function mapping relationship between the high-pressure air pressure and the compressor's equivalent speed is used for variable substitution. Specifically, for each equivalent speed value within the compressor's working range, the corresponding rotatable guide vane angle value is first indexed in the aforementioned linear relationship, and then the corresponding high-pressure air pressure value is indexed in the power function relationship, thus obtaining a new data pair, i.e., a one-to-one correspondence between the high-pressure air pressure value and the rotatable guide vane angle value. Please refer to the appendix. Figure 5 The discrete mapping point set composed of pressure-angle data pairs is obtained, and the discrete mapping point set is fitted into a continuous curve based on the polynomial least squares fitting method of singular value decomposition. The singular value decomposition algorithm used in this application can robustly solve the optimal solution of each coefficient of the polynomial by decomposing the coefficient matrix into a set of orthogonal bases. Even when there is weak noise in the data, the numerical stability of the fitting can be guaranteed. The coefficients of each order of the polynomial of the generated continuous curve form a set of parabolic mapping relationships between high-pressure air pressure and rotatable guide vane angle with the domain. Similarly, this application can also construct a curve showing the relationship between the rotation angle of the rotatable guide vanes and the compressor speed. Please refer to the appendix. Figure 2 ; Based on the gas turbine shutdown state, the electric cylinder control system calibrates the mechanical zero position by recording the stroke endpoint and obtains the linear conversion coefficient through the geometric transmission relationship of the rigid connection between the rotatable guide vane linkage ring and the electric cylinder push rod. That is, the change in the corresponding angle of rotation of the rotatable guide vane linkage ring for each unit length extended by the electric cylinder push rod. Since the change in the corresponding angle of rotation of the rotatable guide vane linkage ring is constant, in order to correct manufacturing and installation errors, the control system drives the electric cylinder push rod to perform a slow, uniform scanning motion of the entire stroke, and simultaneously records the precise angle value fed back by the angular displacement sensor and the push rod stroke value fed back by the electric cylinder itself at a high sampling rate. Based on the stroke-angle data, the slope and intercept parameters of the linear relationship between the rotatable guide vane linkage ring and the electric cylinder push rod are obtained through a regression algorithm, forming a set of linear mapping relationships between the electric cylinder stroke and the rotatable guide vane angle.

[0020] The S2 is based on the control cycle of the gas turbine control system to collect in real time the total temperature value of the inlet airflow measured by the total temperature sensor installed at the compressor inlet and the physical speed value of the compressor measured by the speed sensor installed on the rotor. Based on the preset target value calculation function for the rotatable guide vane angle, bilinear interpolation is used to calculate the rotatable guide vane angle value corresponding to the current total temperature and the current speed, and it is used as the target command for the rotatable guide vane angle. It should be noted that the solution for the target value calculation function of the rotatable guide vane angle is a process based on a binary lookup table and interpolation of a three-dimensional pulse spectrum. First, a three-dimensional pulse spectrum is stored in memory, generated by the compressor design department through iterative simulation of the overall aerodynamic and thermodynamic model and component characteristics. The three coordinate axes represent the compressor inlet total temperature, the compressor physical speed, and the target rotatable guide vane angle. The three-dimensional pulse spectrum refers to the discretized expression of the nonlinear surface relationship between two independent variables (total temperature and speed) and one dependent variable (angle). Therefore, the calibration... After receiving the current total temperature and rotational speed values, the calculation function finds the minimum total temperature interval and minimum rotational speed interval surrounding the current input point in this three-dimensional pulse spectrum, thus locking the four vertex data points. Then, using a bilinear interpolation strategy, it first performs linear interpolation on the two rotational speed layers above and below the locked interval in the total temperature direction to obtain the intermediate angle values ​​corresponding to the current total temperature on the two rotational speed layers. Then, it performs linear interpolation on these two intermediate angle values ​​in the rotational speed direction, and finally calculates the precise rotatable guide vane angle value corresponding to the current total temperature and current rotational speed.

[0021] S2, based on the generated target angle command of the rotatable guide vane, sends it to the electric cylinder control system via fieldbus and drives the push rod to perform linear reciprocating motion via the drive servo motor and reduction mechanism, and changes the rotation angle of the rotatable guide vane through the rotatable guide vane linkage ring. Based on the angular displacement sensor installed on the rotatable guide vane linkage, the actual physical rotation angle of the rotatable guide vane is detected at the same control frequency and sent back to the gas turbine control system as the real-time feedback value of the angular displacement sensor. The deviation between the real-time feedback value of the angular displacement sensor and the target angle command of the rotatable guide vane is calculated. The current deviation is amplified by PID to obtain a fast adjustment command proportional to the magnitude of the deviation. The integral term accumulates the deviation over time to eliminate the small steady-state error that has existed for a long time and ensure that there is no steady-state error. The derivative term calculates the rate of change of the deviation, predicts the trend of the deviation in advance, and generates a damping command to suppress the overshoot and oscillation of the system. After the three commands are combined, the final electric cylinder position fine-tuning command is formed. Based on the drive actuator moving in the direction of reducing the deviation, the closed-loop control is completed. Finally, the deviation between the real-time feedback value of the angular displacement sensor and the target angle command of the rotatable guide vane is continuously and stably controlled within the accuracy range of ±0.5 degrees. During the closed-loop control, at the end of each control cycle, S2 performs data packaging and storage operations. Specifically, it timestamps the generated rotatable guide vane angle target command, the real-time feedback value of the angular displacement sensor, and the electric cylinder push rod stroke feedback value measured by the electric cylinder internal displacement sensor, which is simultaneously obtained from the communication with the electric cylinder control system. These data are then sequentially stored in a fixed-capacity, first-in-first-out circular buffer storage area, forming a multi-source dynamic synchronous data record set. This application records the relationship between the target and the response through the data record set and also establishes a real-time correspondence between the physical displacement of the execution end and the angle expectation of the control end.

[0022] S3 extracts all associated data groups within the most recent complete time window based on the multi-source dynamic synchronous data record set in the circular buffer storage area, and extracts the rotatable guide vane angle target command and the real-time feedback value of the angular displacement sensor based on each data group within the time window. After calculating the absolute value of the difference, it compares it with the preset fault judgment threshold. In order to avoid false alarms caused by random noise or instantaneous disturbances, the process adopts a continuous counting mechanism, that is, continuously monitors the difference. Only when the absolute value of the difference exceeds the threshold for a cumulative number of control cycles within the time window reaches a preset count value, such as 20 consecutive cycles, does the process generate a primary event flag indicating that the angular displacement sensor deviation exceeds the limit. Then, based on the multi-source dynamic synchronous data recording set in the circular buffer storage area, the time series composed of real-time feedback values ​​from the angular displacement sensor and the time series composed of feedback values ​​from the electric cylinder push rod stroke are extracted. Through the Pearson correlation coefficient calculation, a primary event marker for abnormal mechanical transmission chain motion is generated. Specifically, the arithmetic mean of the feedback value sequence and the stroke value sequence within the time window is calculated respectively. The value corresponding to each moment in the two sequences is subtracted from their respective average values ​​to obtain two sets of mean-free deviation sequences. The deviation values ​​at corresponding moments in the two sets of deviation sequences are multiplied together, and all product results within the entire time window are summed. The square of each deviation value in the two sets of deviation sequences is calculated respectively, and all square values ​​are summed. The sum of the products obtained above is divided by the square root of the product of the sum of the squares of the two sets of deviations. The numerical range of this calculation result is between -1 and +1. The closer the value is to one, the stronger the linear positive correlation between the two, that is, the better the rigidity of the mechanical transmission chain. Conversely, if the calculated correlation coefficient is lower than a set threshold, it means that the linear following relationship between the angle change of the angular displacement sensor and the linear displacement change of the electric cylinder push rod has been disrupted. This indicates that mechanical links such as the rotatable guide vane linkage ring connecting the two may have problems such as loosening or a sharp increase in gap. The threshold is determined based on historical experience.

[0023] S2, based on the target command sequence of the rotatable guide vane angle and the feedback value sequence of the electric cylinder push rod stroke from the multi-source dynamic synchronous data recording set, calculates the difference between the current value and the previous value of the target command sequence of the rotatable guide vane angle and the feedback value sequence of the electric cylinder push rod stroke. It then extracts the mathematical symbols of the differences to form the expected motion direction sequence and the actual motion direction sequence of the actuator. A positive sign represents an increase in the expected angle, and a negative sign represents a decrease in the expected angle. The expected motion direction sequence and the actual motion direction sequence of the actuator are compared point-by-point for consistency. If multiple consecutive moments show that the expected motion direction is positive and the actual motion direction of the actuator is negative, and / or the expected motion direction is negative and the actual motion direction of the actuator is positive, a logical contradiction is constituted. This contradiction clearly indicates that the electric cylinder servo system has failed to respond correctly to the control command, and the fault may be located in the servo driver, motor, or its own displacement feedback loop of the electric cylinder. When the cumulative number of such logical contradiction events within the time window exceeds a preset threshold, a primary event marker indicating abnormal feedback response of the electric cylinder and / or its own system is generated. Based on the primary event flags indicating abnormal electric cylinder and / or self-feedback response, the primary event flag indicating excessive angular displacement sensor deviation, and the primary event flag indicating excessive angular displacement sensor deviation, logical operations are performed to complete a comprehensive decision and form a location conclusion. Specifically, in case one, the comprehensive decision logic will output a final judgment conclusion: the fault source is the angular displacement sensor itself, only if the primary event flag indicating excessive angular displacement sensor deviation is true, and both the primary event flag indicating abnormal mechanical transmission chain movement and the primary event flag indicating abnormal electric cylinder or self-feedback response are false. In case two, if both the excessive deviation and abnormal movement flags are true, the fault source is determined to be the mechanical transmission chain such as the rotatable guide vane linkage ring. In case three, if both the excessive deviation and abnormal response flags are true, the fault source is determined to be the electric cylinder actuator assembly.

[0024] S4 sends any adjustment command based on the angular displacement sensor feedback to the electric cylinder based on the positioning conclusion, records the moment the positioning conclusion is generated, and performs data retrieval from the multi-source dynamic synchronous data record set to find the associated data group of the last effective control cycle whose timestamp is earlier than the moment the positioning conclusion is generated. It also extracts the corresponding rotatable guide vane angle target command and electric cylinder push rod stroke feedback value to form real working point data representing the instant before the fault occurred when the system was still in a high-precision synchronous state, as the electric cylinder stroke-angle reference point data pair at the instant before the fault.

[0025] S4 uses the extracted reference point data pairs as constraints, and with the reference point as the center, the intercept parameter of the linear mapping relationship line is used as the variable to be optimized. Based on the stroke value in the reference point, the angle value obtained by adjusting the new linear relationship after the intercept is completely equal to the angle measured by the angular displacement sensor in the reference point. The solution process is to substitute the stroke value of the reference point into the linear relationship expression containing the undetermined intercept, and let its output be equal to the angle value of the reference point. The specific value of the undetermined intercept is directly solved. This newly solved intercept value represents the latest zero position offset of the electric cylinder. The latest zero position offset of the electric cylinder is obtained by solving, and the new intercept replaces the original intercept value in the linear mapping relationship set of electric cylinder stroke-rotatable guide vane angle, completing the online reset and correction of the mapping relationship set.

[0026] After successfully updating the mapping relationship set, S4 inputs the real-time electric cylinder push rod stroke feedback value through communication to the modified electric cylinder stroke-rotatable guide vane angle linear mapping relationship set for conversion, and obtains the equivalent feedback value of the rotatable guide vane angle. The equivalent feedback value of the rotatable guide vane angle is compared with the target command of the rotatable guide vane angle, the deviation is calculated, and a closed-loop adjustment is formed through a proportional-integral-derivative controller.

[0027] Because the initial mapping relationship's zero point has been precisely corrected to the true state before the fault, the equivalent angle feedback value calculated based on the electric cylinder's current stroke at the moment of switching is highly consistent with the control target command at that time, without generating additional control deviations, thus achieving a smooth and disturbance-free control transition. Subsequently, the control system continues to operate in this backup closed-loop mode, maintaining the adjustment accuracy within the new allowable deviation range (e.g., ±1 degree), and finally enters a highly reliable electric cylinder self-feedback closed-loop control state. This state ensures that the gas turbine can still operate safely and stably after the angular displacement sensor fails.

Claims

1. An integrated control method for a gas turbine compressor with a three-redundant configuration of rotatable guide vanes based on an electric cylinder, characterized in that, The specific steps include the following: S1. After the gas turbine control system and electric cylinder control system are initialized, perform zero-point self-test and dial field verification of the angular displacement sensor to establish a multi-source mapping relationship. S2. The gas turbine is started and put into operation. Based on the feedback from the angular displacement sensor, it enters closed-loop control and records multi-source data. S3. Based on the multi-source dynamic synchronous data record set obtained from the multi-source data association record, the analysis object is used to perform tests including the static deviation of the angular displacement sensor exceeding the limit, the quantification of the motion correlation of the transmission chain, and the consistency test of the motion trend. The results of each test are integrated to make a comprehensive decision and obtain the positioning conclusion. S4. Extract and lock the working reference point of the electric cylinder at the moment before the fault based on the positioning conclusion, form a data pair of electric cylinder stroke-angle reference points at the moment before the fault, and correct the multi-source mapping relationship and zero and full position online, and take over the control based on the feedback of the electric cylinder itself.

2. The integrated control method for a three-redundant configuration of rotatable guide vanes in a gas turbine compressor based on an electric cylinder, as described in claim 1, is characterized in that: S1 retrieves test data from the gas turbine whole-machine test and / or historical operation database, collects several sets of steady-state operating point data containing compressor equivalent speed and high-pressure air pressure, and uses compressor equivalent speed as the independent variable and high-pressure air pressure as the dependent variable. The collected discrete steady-state operating point data is analyzed by nonlinear least squares curve fitting method to obtain the optimal parameter set that minimizes the sum of squared errors between the pressure prediction value and the measured value at each point on the fitted curve, and generates coefficient combinations to form a set of power function mapping relationships between high-pressure air pressure and compressor equivalent speed.

3. The integrated control method for a three-redundant configuration of rotatable guide vanes in a gas turbine compressor based on an electric cylinder, as described in claim 1, is characterized in that: S1 is based on the design law between the rotatable guide vane angle and the compressor equivalent speed, which is pre-defined according to the surge margin and overall performance requirements. The compressor equivalent speed in the linear design law is used as the transfer variable, and the variable is substituted by the power function mapping relationship between the high-pressure air pressure and the compressor equivalent speed. A discrete mapping point set composed of pressure-angle data pairs is obtained. The discrete mapping point set is fitted into a continuous curve by the polynomial least squares fitting method based on singular value decomposition. The coefficients of each order of the polynomial of the generated continuous curve and the domain form a set of parabolic mapping relationships between the high-pressure air pressure and the rotatable guide vane angle. Based on the gas turbine shutdown state, the electric cylinder control system calibrates the mechanical zero position by recording the stroke endpoint, and obtains the linear conversion coefficient through the geometric transmission relationship of the rigid connection between the rotatable guide vane linkage ring and the electric cylinder push rod. Based on the stroke-angle data, the slope and intercept parameters of the linear relationship between the rotatable guide vane linkage ring and the electric cylinder push rod are obtained through a regression algorithm, thus forming a set of linear mapping relationships between the electric cylinder stroke and the rotatable guide vane angle.

4. The integrated control method for a three-redundant configuration of rotatable guide vanes in a gas turbine compressor based on an electric cylinder, as described in claim 1, is characterized in that: The S2, based on the control cycle of the gas turbine control system, collects in real time the total temperature value of the inlet airflow measured by the total temperature sensor installed at the compressor inlet and the physical speed value of the compressor measured by the speed sensor installed on the rotor. Based on the preset target value calculation function for the rotatable guide vane angle, it uses bilinear interpolation to calculate the rotatable guide vane angle value corresponding to the current total temperature and current speed, and uses it as the target command for the rotatable guide vane angle.

5. The integrated control method for a three-redundant configuration of rotatable guide vanes in a gas turbine compressor based on an electric cylinder, as described in claim 1, is characterized in that: S2, based on the generated target angle command of the rotatable guide vane, sends it to the electric cylinder control system via fieldbus and drives the push rod to perform linear reciprocating motion via the drive servo motor and reduction mechanism, and changes the rotation angle of the rotatable guide vane through the rotatable guide vane linkage ring. Then, based on the angular displacement sensor installed on the rotatable guide vane linkage loop, the actual physical rotation angle of the rotatable guide vane is detected at the same control frequency, and the real-time feedback value of the angular displacement sensor is sent back to the gas turbine control system. The deviation between the real-time feedback value of the angular displacement sensor and the target angle command of the rotatable guide vane is calculated. The current deviation is amplified by PID to obtain a fast adjustment command that is proportional to the magnitude of the deviation. Based on the drive actuator moving in the direction of reducing the deviation, the closed-loop control is completed. During the closed-loop control, at the end of each control cycle, S2 performs data packaging and storage operations. Specifically, it timestamps the generated rotatable guide vane angle target command, the real-time feedback value of the angular displacement sensor, and the electric cylinder push rod stroke feedback value measured by the electric cylinder internal displacement sensor, which is simultaneously obtained from the communication with the electric cylinder control system. These data are then linked together and sequentially stored in a fixed-capacity, first-in-first-out circular buffer storage area, forming a multi-source dynamic synchronous data record set.

6. The integrated control method for a three-redundant configuration of rotatable guide vanes in a gas turbine compressor based on an electric cylinder, as described in claim 1, is characterized in that: S3 extracts all associated data groups within the most recent complete time window based on the multi-source dynamic synchronous data record set of the circular buffer storage area, and extracts the rotatable guide vane angle target command and the real-time feedback value of the angular displacement sensor based on each data group within the time window. After calculating the absolute value of the difference, it compares it with the preset fault judgment threshold to generate a primary event marker for the angular displacement sensor deviation exceeding the limit. Then, based on the multi-source dynamic synchronous data record set in the circular buffer storage area, the time series composed of real-time feedback values ​​of angular displacement sensors and time series composed of electric cylinder push rod stroke feedback values ​​are extracted. Through Pearson correlation coefficient calculation, a primary event marker for abnormal mechanical transmission chain motion is generated.

7. The integrated control method for a three-redundant configuration of rotatable guide vanes in a gas turbine compressor based on an electric cylinder, as described in claim 1, is characterized in that: S2 calculates the difference between the current value and the previous value of the target command sequence of the rotatable guide vane angle and the feedback value sequence of the electric cylinder push rod stroke based on the multi-source dynamic synchronous data record set. It then extracts the mathematical symbols of the difference to form the command expected motion direction sequence and the actuator actual motion direction sequence. The command expected motion direction sequence and the actuator actual motion direction sequence are compared point by point for consistency. If there are multiple consecutive moments where the command expected motion direction is positive and the actuator actual motion direction is negative and / or the command expected motion direction is negative and the actuator actual motion direction is positive, a primary event marker for abnormal feedback response of the electric cylinder and / or itself is generated. Logical operations are performed based on the primary event flags of abnormal electric cylinder and / or self-feedback response, primary event flags of excessive angular displacement sensor deviation, and primary event flags of excessive angular displacement sensor deviation. After completing the comprehensive decision, a positioning conclusion is formed.

8. The integrated control method for a three-redundant configuration of rotatable guide vanes in a gas turbine compressor based on an electric cylinder, as described in claim 1, is characterized in that: S4 sends any adjustment command based on the angular displacement sensor feedback to the electric cylinder based on the positioning conclusion, records the time when the positioning conclusion is generated, performs data retrieval from the multi-source dynamic synchronous data record set, searches for the associated data group of the last effective control cycle whose timestamp is earlier than the time when the positioning conclusion is generated, and extracts the corresponding rotatable guide vane angle target command and electric cylinder push rod stroke feedback value to form an electric cylinder stroke-angle reference point data pair at the instant before the fault.

9. The integrated control method for a three-redundant configuration of rotatable guide vanes in a gas turbine compressor based on an electric cylinder, as described in claim 8, is characterized in that: S4 uses the extracted reference point data pairs as constraints, and takes the reference point as the center. The intercept parameter of the linear mapping relationship line is used as the variable to be optimized. Based on the stroke value in the reference point, the angle value obtained by adjusting the new linear relationship after the intercept is completely equal to the angle measured by the angular displacement sensor in the reference point. The latest zero position offset of the electric cylinder is obtained by solving the problem. The new intercept replaces the original intercept value in the linear mapping relationship set of electric cylinder stroke-rotatable guide vane angle, thus completing the online reset and correction of the mapping relationship set.

10. The integrated control method for a three-redundant configuration of rotatable guide vanes in a gas turbine compressor based on an electric cylinder, as described in claim 9, is characterized in that: After successfully updating the mapping relationship set, S4 inputs the real-time electric cylinder push rod stroke feedback value through communication to the modified electric cylinder stroke-rotatable guide vane angle linear mapping relationship set for conversion, and obtains the equivalent feedback value of the rotatable guide vane angle. The equivalent feedback value of the rotatable guide vane angle is compared with the target command of the rotatable guide vane angle, the deviation is calculated, and a closed-loop adjustment is formed through a proportional-integral-derivative controller.

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