Servo control on-site calibration system and method

Abstract

The invention discloses an on-site calibration system and method for servo control, belonging to the field of calibration of steam turbine servo control. The invention solves the problem that the calibration control loop of the existing steam turbine servo control device is complicated in the adjustment process of the steam turbine regulating valve and can only be operated remotely. The calibration method of the invention comprises a calibration zero position process and a calibration full position process: a calibration instruction is input into a manual instruction input module, the current state of the calibration instruction is a full-close instruction, and the inlet / exhaust oil ratio calibration control signal generated by the logic control module makes the servo valve completely closed, so that the opening of the steam turbine control actuator is 0, and the calibration zero position is completed; the calibration full position process: a calibration instruction is input into a manual instruction input module, the current state of the calibration instruction is a full-open instruction, and the inlet / exhaust oil ratio calibration control signal generated by the logic control module makes the servo valve completely open, so that the opening of the steam turbine control actuator is 100%, and the calibration full position is completed. It is used to calibrate the steam turbine control actuator.

Description

Technical Field

[0001] The invention belongs to the field of steam turbine servo control calibration. Background Art

[0002] The steam turbine regulating valve is an important component for regulating the steam flow entering the steam turbine. The regulation accuracy of this component is the guarantee for the stability of important controlled parameters such as the speed, power, steam inlet pressure, and back pressure of the steam turbine generator set. The optimization of the calibration control loop of the steam turbine servo control device can improve the efficiency and accuracy of valve setting, thereby ensuring the safe and stable operation of the steam turbine unit. However, the existing calibration control loop of the steam turbine servo control device has the problem that the calibration process of the steam turbine regulating valve is cumbersome and can only be operated remotely. In addition, the remote calibration process requires remote input of codes for control, and the entered code needs to be adjusted in real time according to the returned data during the entire process. Not only is the operation complicated but also time-consuming. Therefore, the above problems need to be solved urgently. Summary of the invention

[0003] The purpose of the present invention is to solve the problem that the existing turbine servo control device calibration control loop has a cumbersome process for adjusting the turbine regulating valve and can only be operated remotely. The present invention provides a servo control on-site calibration system and method.

[0004] Servo control on-site calibration system, which is used to calibrate the opening of the steam turbine control actuator, including two displacement sensors, an acquisition module, a signal processing module, a logic control module, a manual command input module and a servo output module; the two displacement sensors are used to monitor the opening of the steam turbine control actuator, and the two monitored opening signals are sent to the signal processing module through the acquisition module;

[0005] The signal processing module is used to perform analog-to-digital conversion and signal conditioning on the two received opening signals, and then send the obtained two conditioned opening signals to the logic control module;

[0006] A manual instruction input module is used to manually input a calibration instruction and send it to the logic control module; the calibration instruction is a full-close instruction or a full-open instruction;

[0007] A logic control module is used to perform data optimization on the two conditioned opening signals to obtain the optimized opening signal, and then generate an inlet / discharge oil ratio calibration control signal by combining the deviation between the optimized opening signal and the manually entered calibration instruction;

[0008] The signal processing module is also used to perform analog-to-digital conversion and signal conditioning on the inlet / exhaust oil ratio calibration control signal, and then send it to the servo output module for power amplification. The generated drive signal is used to adjust the servo valve opening, so as to control the amount of oil entering the turbine control actuator through the servo valve, thereby making the opening of the turbine control actuator reach a preset position, completing the calibration and realizing the self-calibration of the turbine control actuator.

[0009] The calibration method implemented by the servo-controlled on-site calibration system is characterized in that the calibration method includes a zero position calibration process and a full position calibration process, specifically:

[0010] Zero calibration process:

[0011] Enter the calibration command into the manual command input module. The current state of the calibration command is the full-close command. At this time, the servo control local calibration system enters the zero-position calibration mode, and the inlet / exhaust oil ratio calibration control signal generated by the logic control module makes the servo valve completely closed, so that the opening of the steam turbine control actuator is 0, completing the zero-position calibration;

[0012] Calibration full position process:

[0013] The calibration instruction is entered into the manual instruction input module. The current state of the calibration instruction is the full-open instruction. At this time, the servo control on-site calibration system enters the full-position calibration mode, and the inlet / exhaust oil ratio calibration control signal generated by the logic control module makes the servo valve fully open, so that the opening of the turbine control actuator is 100%, completing the full-position calibration.

[0014] Advantages of the present invention: The present invention optimizes the design of the servo control device, and proposes a servo control on-site calibration system and method, which can realize on-site calibration and manually control the calibration system. Calibration can be achieved through one-step control, and the entire execution process is simple. Specifically, it only needs to enter the corresponding calibration instructions through the manual instruction input module, so that the logic control module can adjust the servo valve opening according to the calibration instructions and the detected opening signal, so that the amount of oil entering the turbine control actuator through the servo valve is controlled, so that the opening of the turbine control actuator reaches the preset position, and the calibration is completed to realize the self-calibration of the turbine control actuator.

[0015] The present invention optimizes the existing turbine servo control device calibration control loop, and provides a specific structure of the servo control on-site calibration system, which can improve the efficiency and accuracy of servo valve setting and opening setting of the turbine control actuator, thereby ensuring the safe and stable operation of the turbine unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the servo-controlled on-site calibration system of the present invention;

[0017] Figure 2 It is the internal logic diagram of the data optimization module;

[0018] Figure 3 This is a schematic diagram of the internal principles of the logic control module. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0021] Embodiment 1:

[0022] See also Figure 1 The present embodiment is described. The servo control on-site calibration system described in the present embodiment is used to calibrate the opening of the steam turbine control actuator, and includes two displacement sensors, an acquisition module, a signal processing module, a logic control module, a manual instruction input module and a servo output module; the two displacement sensors are used to monitor the opening of the steam turbine control actuator, and the two monitored opening signals are sent to the signal processing module through the acquisition module;

[0023] The signal processing module is used to perform analog-to-digital conversion and signal conditioning on the two received opening signals, and then send the obtained two conditioned opening signals to the logic control module;

[0024] A manual instruction input module is used to manually input a calibration instruction and send it to the logic control module; the calibration instruction is a full-close instruction or a full-open instruction;

[0025] A logic control module is used to perform data optimization on the two conditioned opening signals to obtain the optimized opening signal, and then generate an inlet / discharge oil ratio calibration control signal by combining the deviation between the optimized opening signal and the manually entered calibration instruction;

[0026] The signal processing module is also used to perform analog-to-digital conversion and signal conditioning on the inlet / exhaust oil ratio calibration control signal, and then send it to the servo output module for power amplification. The generated drive signal is used to adjust the servo valve opening, so as to control the amount of oil entering the turbine control actuator through the servo valve, thereby making the opening of the turbine control actuator reach a preset position, completing the calibration and realizing the self-calibration of the turbine control actuator.

[0027] In the present embodiment, a servo-controlled on-site calibration system is proposed, and on-site calibration can also be realized to realize manual control of the calibration system. Calibration can be realized by one-step control, and the whole execution process is simple. Specifically, only the corresponding calibration instructions need to be input through the manual instruction input module, so that the logic control module can adjust the servo valve opening according to the calibration instructions and the detected opening signal, so as to control the amount of oil entering the turbine control actuator through the servo valve, so that the opening of the turbine control actuator reaches the preset position, and the calibration is completed to realize the self-calibration of the turbine control actuator.

[0028] In this embodiment, the servo-controlled on-site calibration system can also be used in combination with an existing remote control calibration system.

[0029] In this embodiment, two displacement sensors are set as a redundant setting to avoid malfunction when one of the sensors fails. By using two redundant settings, the opening signal with the best quality can be selected to provide accurate data basis for the generation of subsequent control signals.

[0030] Furthermore, the calibration system also includes a storage module for storing information.

[0031] Furthermore, the calibration system also includes a display module for displaying the opening of the servo valve.

[0032] For further details, see Figure 3 , the logic control module includes a PID controller and a data optimization module;

[0033] A data optimization module is used to optimize the data of the two conditioned opening signals to obtain the optimized opening signals;

[0034] The PID controller is used to perform PID calculation according to the deviation between the optimized opening signal and the manually entered calibration instruction, and generate the inlet / exhaust oil ratio calibration control signal.

[0035] In this preferred embodiment, the specific structure of the logic control module is given, which has a simple structure and is easy to implement. Through the setting of the data optimization module, the signal with the best quality is selected for subsequent operation. The PID controller is an existing controller, which includes an adder, a subtractor, and a proportional link, an integral link, and a differential link. Its specific structure can be found in Figure 3 ;

[0036] Figure 3Among them, the proportional link, integral link and differential link are important links in the PID closed-loop control system solidified in the logic control module; u(t) is the inlet / exhaust ratio calibration control signal output by the logic control module, and the inlet / exhaust ratio calibration control signal is processed to control the servo valve. The inlet / exhaust ratio calibration control signal is usually a current signal of -40mA to +40mA.

[0037] Among them, the opening of the steam turbine control actuator is achieved by adjusting the ratio of the oil intake and the oil discharge through the servo valve to increase the opening, reduce the opening and keep the opening unchanged. The logic control module makes a difference between the manually entered calibration command and the opening signal after optimization, thereby obtaining a variation. After the variation is calculated by PID, the output value u(t) is obtained; u(t) has no actual physical unit. u(t) represents the ratio of the oil intake and the oil discharge of the "steam turbine control actuator" with numerical value and change rate, so as to achieve rapid response and tracking of changes in the control command signal, and can stabilize at the desired opening value or the desired switching speed value, so as to ensure the stability of the actuator control.

[0038] For further details, see Figure 2 ,The data optimization module includes a high selection module B1, selection modules T1 to T3, quality judgment modules Q1 to Q2, an OR gate and an AND gate;

[0039] The high selection module B1 is used to receive the two conditioned opening signals, and select the opening signal with the largest amplitude from the two, and send it to the first input terminal of the selection module T2;

[0040] The quality judgment module Q1 is used to judge the quality of the first conditioned opening signal L1, and convert the judgment result into a digital quantity and output it to the third input terminal of the selection module T1, the first input terminal of the OR gate and the first input terminal of the AND gate;

[0041] The quality judgment module Q2 is used to judge the quality of the first conditioned opening signal L2, and convert the judgment result into a digital quantity and output it to the second input end of the OR gate and the second input end of the AND gate;

[0042] The digital quantity output by the quality judgment modules Q1 and Q2 is 0 or 1, 1 represents good quality and 0 represents bad quality;

[0043] The first and second input ends of the selection module T1 are used to receive the first and second conditioned opening signals L2 respectively. When the digital quantity output by the quality judgment module Q1 received by the selection module T1 is 0, the selection module T1 outputs the first conditioned opening signal L1 to the second input end of the selection module T2; when the digital quantity output by the quality judgment module Q1 received by the selection module T1 is 1, the selection module T1 outputs the first conditioned opening signal L2 to the second input end of the selection module T2;

[0044] The third input terminal of the selection module T2 is connected to the output terminal of the OR gate. When the OR gate outputs the digital value 0, the output terminal of the selection module T2 outputs the signal received by its first input terminal to the first input terminal of the selection module T3. When the OR gate outputs the digital value 1, the output terminal of the selection module T2 outputs the signal received by its second input terminal to the first input terminal of the selection module T3.

[0045] The second input terminal of the selection module T3 is used to receive a preset signal;

[0046] The third input end of the selection module T3 is connected to the output end of the AND gate. When the AND gate outputs a digital value of 0, the output end of the selection module T3 outputs the signal received by its first input end, and uses the signal as the optimized opening signal; when the AND gate outputs a digital value of 1, the output end of the selection module T3 outputs the signal received by its second input end, and uses the signal as the optimized opening signal.

[0047] In this preferred implementation, the specific operation logic inside the data optimization module is given. L1 and L2 are the two displacement sensors received by the logic module and the real-time signals monitored by the displacement sensors, respectively. L1 and L2 pass through the high selection link B1, and the larger value of the two signals is output from B1; Q1 and Q2 are quality judgment links, and T1, T2, and T3 are selection links.

[0048] The final result output by the data optimization module is:

[0049] a. When L1 and L2 are both of good quality, the data optimization module outputs the larger value of L1 and L2;

[0050] b, when L1 is of good quality and L2 is of bad quality, the output of the data optimization module is equal to L1;

[0051] c. When L1 is of bad quality and L2 is of good quality, the data optimization module outputs L2;

[0052] d. When L1 is of bad quality and L2 is of bad quality, the optimal module outputs a preset signal. It should be noted that the preset signal is a protection fixed value at this time. The fixed value can be adjusted according to the characteristics of the execution structure. This setting can automatically adjust the actuator to a safe position when both displacement sensors fail. So far, the signal processing and optimization of the two-way local displacement sensor are completed.

[0053] Furthermore, the manual command input module includes three key units, namely a setting key unit, a zero position calibration key unit and a full position calibration key unit;

[0054] Setting button unit, used to enter zero calibration mode or full calibration mode;

[0055] The zero-position key unit is used to generate a full-close command;

[0056] Calibrate the full-position button unit to generate a full-open command.

[0057] In this preferred embodiment, when the setting button unit and the zero calibration button unit work at the same time, the calibration system enters the zero calibration mode. After the zero calibration process is completed, the button in the setting button unit is pressed alone (that is, the setting button unit works independently) to exit the zero calibration mode.

[0058] When the setting button unit and the calibration zero position button unit work at the same time, the calibration system enters the full position calibration mode. After the full position calibration process is completed, press the button in the setting button unit alone (that is, the setting button unit works independently) to exit the full position calibration mode.

[0059] Embodiment 2:

[0060] See also Figure 1 Description of the present embodiment, this embodiment adopts the calibration method implemented by the servo-controlled on-site calibration system, the calibration method includes a zero position calibration process and a full position calibration process, specifically:

[0061] Zero calibration process:

[0062] Enter the calibration command into the manual command input module. The current state of the calibration command is the full-close command. At this time, the servo control local calibration system enters the zero-position calibration mode, and the inlet / exhaust oil ratio calibration control signal generated by the logic control module makes the servo valve completely closed, so that the opening of the steam turbine control actuator is 0, completing the zero-position calibration;

[0063] Calibration full position process:

[0064] The calibration instruction is entered into the manual instruction input module. The current state of the calibration instruction is the full-open instruction. At this time, the servo control on-site calibration system enters the full-position calibration mode, and the inlet / exhaust oil ratio calibration control signal generated by the logic control module makes the servo valve fully open, so that the opening of the turbine control actuator is 100%, completing the full-position calibration.

[0065] In this embodiment, the calibration method implemented by the servo-controlled on-site calibration system can realize on-site calibration and manually control the calibration system. Calibration can be achieved in one step, and the entire execution process is simple. Specifically, only the corresponding calibration instructions need to be entered through the manual instruction input module, so that the logic control module can adjust the servo valve opening according to the calibration instructions and the detected opening signal, so as to control the amount of oil entering the turbine control actuator through the servo valve, so that the opening of the turbine control actuator reaches the preset position, and the calibration is completed to realize the self-calibration of the turbine control actuator.

[0066] Furthermore, when the servo control in-situ calibration system further includes a storage module and a display module;

[0067] A storage module, used for storing conditioned opening signals of two displacement sensors received by the logic control module during the zero position calibration process and the full position calibration process;

[0068] The display module is used to display the opening signal after optimization by the logic control module and the inlet / exhaust oil ratio calibration control signal generated by the logic control module. It is also used to display the opening information of the turbine control actuator and the opening information of the servo valve during the zero position calibration process and the full position calibration process.

[0069] In this preferred embodiment, the opening information of the steam turbine control actuator and the opening information of the servo valve can be displayed during the zero position calibration process and the full position calibration process, so that the calibration accuracy can be felt more intuitively.

[0070] Furthermore, the manual command input module includes three key units, namely a setting key unit, a zero position calibration key unit and a full position calibration key unit;

[0071] Setting button unit, used to enter zero calibration mode or full calibration mode;

[0072] The zero-position key unit is used to generate a full-close command;

[0073] Calibrate the full-position button unit to generate a full-open command.

[0074] In this preferred embodiment, all the key units include one key. When the keys of the setting key unit and the zero calibration key unit are pressed at the same time, the calibration system enters the zero calibration mode. After the zero calibration process is completed, the button in the setting key unit is pressed separately (that is, the setting key unit works independently) to exit the zero calibration mode.

[0075] When the buttons of the setting button unit and the calibration zero position button unit are pressed at the same time (that is, the two units work at the same time), the calibration system enters the full-position calibration mode. After the full-position calibration process is completed, press the button in the setting button unit alone (that is, the setting button unit works independently) to exit the full-position calibration mode.

[0076] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in other described embodiments.

Claims

1. A servo control on-site calibration system, which is used to calibrate the opening of a steam turbine control actuator, and is characterized in that: It includes two displacement sensors, an acquisition module, a signal processing module, a logic control module, a manual command input module and a servo output module; the two displacement sensors are used to monitor the opening of the steam turbine control actuator, and the two monitored opening signals are sent to the signal processing module through the acquisition module; The signal processing module is used to perform analog-to-digital conversion and signal conditioning on the two received opening signals, and then send the obtained two conditioned opening signals to the logic control module; A manual instruction input module is used to manually input a calibration instruction and send it to the logic control module; the calibration instruction is a full-close instruction or a full-open instruction; A logic control module is used to perform data optimization on the two conditioned opening signals to obtain the optimized opening signal, and then generate an inlet / discharge oil ratio calibration control signal by combining the deviation between the optimized opening signal and the manually entered calibration instruction; The signal processing module is also used to perform analog-to-digital conversion and signal conditioning on the inlet / exhaust oil ratio calibration control signal, and then send it to the servo output module for power amplification. The generated drive signal is used to adjust the servo valve opening, so that the amount of oil entering the steam turbine control actuator through the servo valve is controlled, so that the opening of the steam turbine control actuator reaches a preset position, and the calibration is completed to realize the self-calibration of the steam turbine control actuator; The logic control module includes a PID controller and a data optimization module; A data optimization module is used to optimize the data of the two conditioned opening signals to obtain the optimized opening signals; A PID controller is used to perform PID calculation according to the deviation between the optimized opening signal and the manually entered calibration instruction, and generate an inlet / discharge oil ratio calibration control signal; The data optimization module includes a high selection module B1, selection modules T1 to T3, quality judgment modules Q1 to Q2, an OR gate and an AND gate; The high selection module B1 is used to receive the two conditioned opening signals, and select the opening signal with the largest amplitude from the two, and send it to the first input terminal of the selection module T2; The quality judgment module Q1 is used to judge the quality of the first conditioned opening signal L1, and convert the judgment result into a digital quantity and output it to the third input terminal of the selection module T1, the first input terminal of the OR gate and the first input terminal of the AND gate; The quality judgment module Q2 is used to judge the quality of the first conditioned opening signal L2, and convert the judgment result into a digital quantity and output it to the second input end of the OR gate and the second input end of the AND gate; The digital quantity output by the quality judgment modules Q1 and Q2 is 0 or 1, 1 represents good quality and 0 represents bad quality; The first and second input ends of the selection module T1 are used to receive the first and second conditioned opening signals L2 respectively. When the digital quantity output by the quality judgment module Q1 received by the selection module T1 is 0, the selection module T1 outputs the first conditioned opening signal L1 to the second input end of the selection module T2; when the digital quantity output by the quality judgment module Q1 received by the selection module T1 is 1, the selection module T1 outputs the first conditioned opening signal L2 to the second input end of the selection module T2; The third input terminal of the selection module T2 is connected to the output terminal of the OR gate. When the OR gate outputs the digital value 0, the output terminal of the selection module T2 outputs the signal received by its first input terminal to the first input terminal of the selection module T3. When the OR gate outputs the digital value 1, the output terminal of the selection module T2 outputs the signal received by its second input terminal to the first input terminal of the selection module T3. The second input terminal of the selection module T3 is used to receive a preset signal; The third input end of the selection module T3 is connected to the output end of the AND gate. When the AND gate outputs a digital value of 0, the output end of the selection module T3 outputs the signal received by its first input end, and uses the signal as the optimized opening signal; when the AND gate outputs a digital value of 1, the output end of the selection module T3 outputs the signal received by its second input end, and uses the signal as the optimized opening signal.

2. The servo control on-site calibration system according to claim 1, characterized in that: The calibration system also includes a storage module for storing information.

3. The servo control on-site calibration system according to claim 1, characterized in that: The calibration system also includes a display module for displaying the opening of the servo valve.

4. The servo control on-site calibration system according to claim 1, characterized in that: The manual command input module includes three key units, namely, a setting key unit, a zero position calibration key unit and a full position calibration key unit; Setting button unit, used to enter zero calibration mode or full calibration mode; The zero-position key unit is used to generate a full-close command; Calibrate the full-position button unit to generate a full-open command.

5. The calibration method implemented by the servo-controlled on-site calibration system according to claim 1 is characterized in that: The calibration method includes a zero position calibration process and a full position calibration process, specifically: Zero calibration process: Enter the calibration command into the manual command input module. The current state of the calibration command is the full-close command. At this time, the servo control local calibration system enters the zero-position calibration mode, and the inlet / exhaust oil ratio calibration control signal generated by the logic control module makes the servo valve completely closed, so that the opening of the steam turbine control actuator is 0, completing the zero-position calibration; Calibration full position process: Enter the calibration instruction into the manual instruction input module. The current state of the calibration instruction is the full-open instruction. At this time, the servo control on-site calibration system enters the full-position calibration mode, and the inlet / exhaust oil ratio calibration control signal generated by the logic control module makes the servo valve fully open, so that the opening of the turbine control actuator is 100%, completing the full-position calibration.

6. The calibration method according to claim 5, characterized in that: The servo-controlled in-situ calibration system also includes a storage module and a display module; A storage module, used for storing conditioned opening signals of two displacement sensors received by the logic control module during the zero position calibration process and the full position calibration process; The display module is used to display the opening signal after optimization by the logic control module and the inlet / exhaust oil ratio calibration control signal generated by the logic control module. It is also used to display the opening information of the turbine control actuator and the opening information of the servo valve during the zero position calibration process and the full position calibration process.

7. The calibration method according to claim 5, characterized in that: The manual command input module includes three key units, namely, a setting key unit, a zero position calibration key unit and a full position calibration key unit; Setting button unit, used to enter zero calibration mode or full calibration mode; The zero-position key unit is calibrated to generate a full-close command; Calibrate the full-position button unit to generate a full-open command.

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