Intelligent steam pressure control method
By using an intelligent steam pressure control method, the main valve and auxiliary valve are dynamically allocated. Combined with PID control and feedforward compensation, the problems of regulation overshoot and insufficient redundancy in existing steam pressure control technologies are solved, achieving high-precision, fast-response, and fault-tolerant steam pressure control.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-02
- Publication Date
- 2026-03-10
AI Technical Summary
Existing steam pressure control methods suffer from severe overshoot under high-frequency load fluctuations, large pressure fluctuation amplitudes, and insufficient redundancy, which prevents the system from quickly switching to standby valves. Traditional dual-valve control lacks dynamic role allocation logic, resulting in uneven flow distribution.
An intelligent steam pressure control method is adopted, which dynamically allocates the main valve and the auxiliary valve, combined with PID control and feedforward compensation, monitors the load change rate, shortens the response delay, and realizes coordinated regulation and fault tolerance of the main valve and the auxiliary valve.
The dynamic response has been optimized, resulting in reduced pressure fluctuations, improved synchronization accuracy, enhanced fault tolerance, improved flow distribution uniformity, reduced equipment wear, and lower maintenance costs.
Smart Images
Figure CN121635515A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present disclosure relates to the technical field of steam pressure control, in particular to an intelligent steam pressure control method. BACKGROUND
[0002] In the scenarios of coal-gas coupled power generation system, chemical process industry, etc., the adjustment of steam pressure is needed. In the prior art, the traditional steam pressure control is usually adjusted by single valve or simple double valve parallel mode.
[0003] The steam pressure control method in the prior art has the following technical defects: first, when the steam pressure is adjusted by a single valve, the response speed of the electric or pneumatic actuator is much lower than the steam pressure change speed, so under high-frequency load fluctuation (such as ±10% / min), the adjustment overshoot is serious, and the pressure fluctuation amplitude (actual pressure value deviates from the target pressure) can reach more than 10%. For details, please refer to Figure 1 ; second, the redundancy is insufficient: when the single valve fails, the system cannot quickly switch to the standby valve, which easily causes shutdown accidents; third, the traditional double valve control lacks dynamic role allocation logic, and the synchronization error of the main and auxiliary valve opening is large (>10%), which leads to uneven flow distribution. In the existing steam pressure regulation technology, although there is double valve redundancy control, please refer to Figure 2 , but the problem of coordinated response under load mutation is not solved. SUMMARY
[0004] The present disclosure is proposed in view of the above problems. The present disclosure provides an intelligent steam pressure control method.
[0005] According to one aspect of the present disclosure, an intelligent steam pressure control method is provided, which comprises the following steps: S1, obtaining a target flow required by a target load; S2, dynamically allocating a main valve and an auxiliary valve for an electric regulating valve in parallel at the inlet of a steam pipeline; S3, adjusting the steady-state pressure of the main valve and outputting a main valve opening instruction to control the main valve opening; S4, monitoring the load change rate and controlling the auxiliary valve to intervene in feedforward compensation, and shortening the response delay to a first set time; S5, taking the main valve opening instruction as a reference value of the auxiliary valve opening, and performing opening deviation synchronization every second set time.
[0006] The intelligent steam pressure control method as described above, wherein, optionally, step S2 comprises: S21, setting the electric regulating valve with an initial valve position close to 50% opening as the main valve; S22, actively adjusting the main valve and controlling the auxiliary valve to be closed and kept; until the auxiliary valve unlocking condition is met; wherein the auxiliary valve unlocking condition includes main valve and auxiliary valve switching, downstream process sudden disturbance, main valve failure and main valve and auxiliary valve synchronization; S23, when the switching condition of the main valve and the auxiliary valve is met, the original main valve is changed to the auxiliary valve, and the original auxiliary valve is changed to the main valve.
[0007] The intelligent steam pressure control method as described above, wherein, optionally, the switching condition of the main valve and the auxiliary valve is at least one of the following conditions: Main valve instruction or feedback failure; Main valve instruction and feedback deviation greater than the first percentage; Main steam pressure total failure; Main steam pressure and set deviation greater than the first pressure value; Main valve jump deviation greater than the second percentage; Main valve and auxiliary valve difference deviation greater than the third percentage.
[0008] The intelligent steam pressure control method as described above, wherein, optionally, step S3 includes: adjusting the main valve for steady-state pressure according to the set parameters through PID control; and combining real-time pressure feedback, correcting the main valve action amount through main valve PID output to form a closed-loop control; Wherein, the set parameters of the PID are obtained by the following steps: S031, confirming that the regulating valve mechanical structure is normal and the system is in a stable state; S032, setting initial parameters; S033, putting into closed-loop control, inputting step signal, and recording process curve; S034, observing whether the system response is stable; when the system response is not stable, adjusting the initial parameters until the system is stable; S035, checking the oscillation condition and adjusting the integral time and / or the differential time when overshoot occurs; S036, evaluating whether the performance index meets the condition, and repeating steps S033 to S035 until the performance index meets the condition; S037, recording the adjusted parameters as set parameters.
[0009] The intelligent steam pressure control method as described above, wherein, optionally, step S5 includes the following steps: Every second set time, detect the opening deviation of the double valves, and when the deviation of the two is greater than the fourth percentage, trigger the synchronization instruction.
[0010] The intelligent steam pressure control method as described above, wherein, optionally, when the load mutation rate is greater than the set change rate, the control of the auxiliary valve starts the feedforward compensation, and the auxiliary valve opening is adjusted to the fifth percentage of the target value.
[0011] The intelligent steam pressure control method as described above, wherein, optionally, the pre-compensation signal of the feedforward compensation is generated by a preset model based on the DEH frequency modulation principle of the steam turbine.
[0012] The intelligent steam pressure control method as described above, wherein, optionally, when any electric regulating valve fails, the other electric regulating valve is switched to a wide-area regulation mode, the system stability is maintained by expanding the regulating range of the electric regulating valve, and the pressure transient peak value during load rejection is prevented from exceeding the safety threshold according to a preset valve position dynamic limitation curve.
[0013] The intelligent steam pressure control method as described above, wherein, optionally, in the wide-area regulation mode, the minimum value among the main valve opening instruction, the upper limit of the valve position output, and the zero position of the pressure reducing valve interlock is taken as the actual output instruction of the regulating valve to control the electric regulating valve.
[0014] As will be described in detail below, according to the intelligent steam pressure control method of the embodiments of the present disclosure, the main valve and the auxiliary valve are dynamically allocated for the electric regulating valves in parallel at the inlet of the steam pipeline, the load change rate is monitored, the auxiliary valve is controlled to intervene in the feedforward compensation, and the response delay is shortened to a first set time, thereby improving the synchronization accuracy and fault tolerance capability and optimizing the dynamic response.
[0015] It is to be understood that both the foregoing general description and the following detailed description are exemplary and intended to provide further explanation of the subject technology. BRIEF DESCRIPTION OF DRAWINGS
[0016] The foregoing and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description, which proceeds with reference to the accompanying drawings. The drawings are provided to illustrate embodiments of the present disclosure and, together with the detailed description, serve to explain the present disclosure and do not constitute a limitation thereof. In the drawings, like reference numerals refer to like elements or steps throughout.
[0017] Figure 1 is a schematic diagram of the pressure PID regulation result of a single pressure reducing valve in the prior art; Figure 2 is a structural schematic diagram of a double-valve; Figure 3 is a step flowchart of the method proposed by the present disclosure; Figure 4 is a control logic block diagram proposed by the present disclosure; Figure 5 The method proposed in the present disclosure controls the result of the curve. DETAILED DESCRIPTION
[0018] In order to make the purposes, technical solutions and advantages of the present disclosure more obvious, the following will describe the example embodiments according to the present disclosure in detail with reference to the drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all the embodiments of the present disclosure, and it should be understood that the present disclosure is not limited by the example embodiments described here.
[0019] For the problems in the background art, for the existing double valve redundancy control, the problem of coordinated response when the load suddenly changes cannot be solved, the main reason is that the feedforward compensation mechanism is not combined, and there is still a defect in the regulation time process, in the prior art, the regulation time usually exceeds 30 seconds. The present disclosure provides the following technical solutions to provide a double valve coordinated control method capable of considering fast response, high precision synchronization and fault tolerance.
[0020] Please refer to Figures 3 to 5 The present disclosure proposes an intelligent steam pressure control method, which comprises the following steps: S1, obtaining a target flow required by a target load; specifically, the target flow is the flow required by the load after the main steam flow is corrected.
[0021] In specific implementation, the flow required by the load after the main steam flow is corrected is determined by the relationship between flow and load and the main steam flow correction function. This step mainly comprises the following specific steps: S11, obtaining the relationship between flow and load according to the load of the steam turbine.
[0022] S12, obtaining the main steam pressure, the main steam temperature and the back pressure, and obtaining the required target flow according to the main steam correction function determined by the main steam pressure, the main steam temperature and the back pressure and the relationship between flow and load. Specifically, the main steam flow correction function is related to the main steam temperature, the main steam pressure and the back pressure, and different main steam pressure, main steam temperature and back pressure will affect the required target flow, therefore, the flow is corrected according to the actual main steam pressure, main steam temperature and back pressure, and the corrected flow is taken as the required target flow, which is beneficial to improve the control precision.
[0023] S2, dynamically distributing the main valve and the auxiliary valve for the electric regulating valve connected in parallel at the inlet of the steam pipeline. That is, in the present disclosure, the main valve and the auxiliary valve are not fixed, and in any state, one is the main valve and the other is the auxiliary valve; and for any valve, it may be distributed as the main valve or the auxiliary valve in different states.
[0024] S21, set the electric regulating valve with an initial valve position distance of 50% opening as the main valve. In this way, the adjustment range of the electric regulating valve is reduced, and the main valve can be adjusted to the required opening more quickly.
[0025] S22, actively adjust the main valve and control the auxiliary valve to be locked; until the auxiliary valve unlocking condition is met; in specific implementation, when the auxiliary valve is locked, its opening remains unchanged. The auxiliary valve unlocking condition includes main valve and auxiliary valve switching, downstream process sudden disturbance, main valve failure, and main valve and auxiliary valve synchronization.
[0026] S23, when the main valve and auxiliary valve switching condition is met, the original main valve is changed to the auxiliary valve, and the original auxiliary valve is changed to the main valve. In specific implementation, the main valve and auxiliary valve switching condition is at least one of the following conditions: Main valve command or feedback failure; that is, the main valve command fails or the feedback signal fails.
[0027] Main valve command and feedback deviation is greater than the first percentage; specifically, when the main valve command and feedback deviation is greater than 7%, it indicates that a failure occurs.
[0028] Main steam pressure total failure; when the main steam pressure fails, the main valve and auxiliary valve are switched.
[0029] Main steam pressure and set value deviation is greater than the first pressure value; specifically, the deviation between the main steam pressure and the set value is greater than 0.5 Mpa, indicating that the main steam pressure deviation is too large.
[0030] Main valve jump deviation is greater than the second percentage; specifically, when the main valve jump deviation is greater than 10%, the main valve and auxiliary valve are switched.
[0031] Main valve and auxiliary valve difference deviation is greater than the third percentage. When the deviation between the main valve and the auxiliary valve is greater than 10%, the main valve and the auxiliary valve are switched.
[0032] In the present disclosure, switching the main valve and the auxiliary valve means that the original main valve becomes the auxiliary valve, and the original auxiliary valve becomes the main valve.
[0033] S3, steady pressure regulation is performed on the main valve, and a main valve opening command is output to control the main valve opening; according to the set parameters, the steady pressure regulation is performed on the main valve through PID control; and combined with real-time pressure feedback, the main valve action amount is corrected through the main valve PID output to form a closed-loop control.
[0034] Wherein, the set parameters of the PID are obtained by the following steps: S031, confirm that the regulating valve mechanical structure is normal and the system is in a stable state.
[0035] S032, set the initial parameters; wherein, the initial value of P is 0, the initial value of I is infinity, and the initial value of D is 0.
[0036] S033, inputting a step signal and recording the process curve under closed loop control.
[0037] S034, observing whether the system response is stable; when the system response is not stable, adjusting the initial parameters until the system is stable.
[0038] S035, checking the oscillation and adjusting the integral time and / or the differential time when the overshoot occurs.
[0039] S036, evaluating whether the performance index meets the condition; when the performance index does not meet the condition, repeating steps S033 to S035; until the performance index meets the condition.
[0040] S037, recording the adjusted parameters as the set parameters.
[0041] After the above steps S031 to S037, the critical gain Ku of the system is 0.2, the critical period Pu is 200 seconds, and the final parameters P are 300%, i.e., kp is 0.33, Ti is 100 seconds, and Td is 25 seconds.
[0042] S4, monitoring the load change rate and controlling the intervention of the secondary valve for feedforward compensation to shorten the response delay to a first set time. That is, when the load suddenly changes, the secondary valve is adjusted accordingly to eliminate the impact of the sudden load change by adjusting the opening of the secondary valve. Specifically, the secondary valve is normally locked and does not participate in regulation; when a sudden disturbance occurs in the downstream steam process, such as the action of a drain valve or a sudden change in the load command of a steam turbine, the secondary valve is unlocked and the disturbance source is modeled to calculate the future flow change that will soon occur, and the valve should be adjusted to calculate the theoretical action of the valve to directly pre-adjust the secondary valve. The effect is that the secondary valve is used to mostly offset the sudden disturbance in the downstream, which may not be accurate but is very timely. Accurate adjustment still relies on the main valve to control the pressure. The response delay refers to the time difference from the time when the demand for downstream steam changes to the time when the regulating valve starts to adjust. Because steam is a compressible gas, it takes a certain time for the steam flow to change to the steam pressure to be reflected, and the response delay is also caused by the dead zone of the regulating valve actuator. Through this control method, the response delay can be directly shortened to within 1 second.
[0043] Specifically, when the load mutation rate is greater than the set change rate, the control sub-valve starts the feedforward compensation, and the sub-valve opening is adjusted to the fifth percentage of the target value. In actual application, the fifth percentage can be set to 80%. That is, the sudden event of the downstream steam process system is monitored, when the sudden event occurs, and the steam flow change rate or the load mutation rate is greater than the set change rate, the feedforward compensation works, and the sub-valve is unlocked. The sub-valve opening is adjusted to 80% of the target adjustment amount, which is the theoretical calculation value through the flow opening function. In specific implementation, the pre-compensation signal of the feedforward compensation is generated by a preset model based on the frequency modulation principle of the steam turbine DEH.
[0044] S5, taking the main valve opening degree instruction as the reference value of the sub-valve opening degree, and performing opening degree deviation synchronization every second set time (15 seconds).
[0045] Specifically, the double-valve opening degree deviation is detected every second set time, and when the deviation of the two is greater than the fourth percentage (3%), the synchronization instruction is triggered. In specific implementation, the second set time is between 10 seconds and 20 seconds, and preferably, 15 seconds can be selected. Normally, the pressure regulating PID loop only acts on the main valve, but when the synchronization instruction is triggered, the opening valve instruction and the closing valve instruction of the pressure regulating PID loop are separated, the valve with smaller opening valve position is needed to open, and the valve with larger closing valve position is needed to close, until the synchronization instruction disappears. When the pressure is stable, the PID regulation has neither opening valve instruction nor closing valve instruction, and then it is temporarily inactivated, and when there is a new valve position adjustment requirement, the synchronization is performed. Through the synchronization regulation, the flow distribution uniformity can be effectively ensured.
[0046] In actual application, when any electric regulating valve fails, the other electric regulating valve is switched to the wide-area regulation mode, the system stability is maintained by expanding the regulating range of the electric regulating valve, and according to the preset valve position dynamic limiting curve, the pressure transient peak value is prevented from exceeding the safety threshold value during load rejection. Specifically, load rejection refers to that the downstream steam process rejects all or part of the steam consumption. In the wide-area regulation mode, the minimum value among the main valve opening degree instruction, the valve position output upper limit, and the zero position of the pressure reducing valve interlock is taken as the actual output instruction of the regulating valve, so as to control the electric regulating valve.
[0047] In the present disclosure, the main valve cooperates with the auxiliary valve logic: the main valve is responsible for steady-state pressure regulation, using an adaptive PID algorithm (parameters can be: P=80%, Ti=45s, Td=8s), with a target pressure dead zone of ±0.1MPa; when the load change rate >5% / min, the auxiliary valve intervenes in feedforward compensation, with a response delay shortened to 1 second; the main valve opening command is used as the auxiliary valve reference value, with opening deviation synchronization every 15 seconds to ensure an error <3%. Single valve fault switching: when either valve fails, the other valve switches to a wide-area regulation mode, maintaining system stability by expanding the flow regulation range (50%-100%); dynamic limit protection: a dynamic limit curve is set for the valve position to prevent the pressure transient peak from exceeding the safety threshold (e.g. 7.28MPa) during load rejection.
[0048] The above describes an intelligent steam pressure control method according to an embodiment of the present disclosure, which dynamically allocates a main valve and an auxiliary valve for the electric regulating valves in parallel at the inlet of the steam pipeline; the main valve is used for steady-state pressure regulation and outputs a main valve opening command to control the main valve opening; the load change rate is monitored, and the auxiliary valve intervenes in feedforward compensation, with a response delay shortened to a first set time; the main valve opening command is used as the reference value for the auxiliary valve opening, with opening deviation synchronization every second set time. The following effects are achieved: dynamic response optimization: under a 2.5MW / min load change, the pressure fluctuation amplitude is reduced from 0.8MPa to 0.4MPa, and the regulation time is shortened from 30 seconds to 10 seconds; synchronization accuracy improvement: the double-valve opening synchronization error is <3%, and the flow distribution uniformity is 97%; fault tolerance capability: after a single valve failure, the system switching time is <2 seconds, and the pressure transient fluctuation is <0.6MPa; economic verification: by reducing valve frequent operation, the equipment wear rate is reduced by 40%, and the annual maintenance cost is saved by more than 2 million yuan.
[0049] The present disclosure provides a process situation where the downstream steam flow changes dramatically, with a flow change range of 0-100% per minute, and a high requirement for steam pressure stability (within ±10% of the rated pressure), preventing both overpressure and underpressure. Using the strategies and methods described in the present disclosure, the pain points of over-regulation caused by the response lag of the regulating valve actuator in the prior art can be overcome, and the shortcomings of the prior art, where one regulating valve cannot quickly and smoothly switch to the standby valve when a valve fails, can be solved. The shortcomings of the prior art, where two regulating valves cannot be cooperatively regulated, can also be solved.
[0050] The above describes the basic principles of the present disclosure in conjunction with specific embodiments, but it should be noted that the advantages, benefits, effects and the like mentioned in the present disclosure are only examples and are not limiting, and these advantages, benefits, effects and the like cannot be considered as necessary for each embodiment of the present disclosure. In addition, the specific details of the above disclosure are only for the purpose of example and understanding, and are not limiting, and the above details do not limit the present disclosure to be necessarily implemented with the above specific details.
[0051] The block diagrams of the devices, apparatuses, equipment, systems involved in the present disclosure are only illustrative examples and are not intended to require or imply the connection, arrangement, configuration as shown in the block diagram. As those skilled in the art will recognize, these devices, apparatuses, equipment, systems can be connected, arranged, configured in any manner. Words such as "include", "contain", "have" and the like are open-ended words, meaning "including but not limited to", and can be used interchangeably. The words "or" and "and" used herein refer to the word "and / or", and can be used interchangeably unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to", and can be used interchangeably.
[0052] In addition, as used herein, "or" used in the listing of items in the phrase "at least one of the items" indicates a disjunctive list, such that, for example, a list of "at least one of A, B, or C" means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). In addition, the word "exemplary" does not mean that the described example is preferred or better than other examples.
[0053] It should also be noted that in the systems and methods of the present disclosure, the components or steps can be decomposed and / or recombined. These decompositions and / or recombinations should be considered equivalents of the present disclosure.
[0054] Various changes, substitutions and alterations can be made to the techniques described herein without departing from the teachings of the technology defined by the appended claims. In addition, the scope of the claims of the present disclosure is not limited to the specific aspects of the processes, machines, manufactures, compositions of matter, means, methods and acts of the above described. Processes, machines, manufactures, compositions of matter, means, methods or acts currently existing or later developed that perform substantially the same function or achieve substantially the same result as the corresponding aspects described herein can be utilized. Accordingly, the appended claims include within their scope such processes, machines, manufactures, compositions of matter, means, methods or acts.
[0055] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other aspects without departing from the scope of the disclosure. Thus, the present disclosure is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
[0056] The above description has been presented to enable any person skilled in the art to make or use the disclosure. Furthermore, the purpose of the above description is not intended to limit the embodiments of the present disclosure to the form disclosed herein. Although various example aspects and embodiments have been discussed above, those of ordinary skill in the art will appreciate a variety of modifications, alternatives, permutations, additions, and sub-combinations of the described aspects and embodiments.
Claims
1. A method of intelligent steam pressure control, characterized by, The method comprises the following steps: S1, obtaining a target flow required by a target load; S2, dynamically distributing a main valve and a secondary valve for electrically-controlled regulating valves connected in parallel at an inlet of a steam pipeline; S3, regulating a steady-state pressure of the main valve and outputting a main valve opening degree instruction to control the opening degree of the main valve; S4, monitoring a load change rate and controlling the secondary valve to intervene in feedforward compensation and shorten a response delay to a first set time; S5, taking the main valve opening degree instruction as a reference value of a secondary valve opening degree and synchronizing an opening degree deviation every second set time.
2. The intelligent steam pressure control method of claim 1, wherein, Step S1 comprises: S11, obtaining a flow-load relationship according to a steam turbine load; S12, obtaining a main steam pressure, a main steam temperature and a back pressure, and obtaining the required target flow according to a main steam correction function determined by the main steam pressure, the main steam temperature and the back pressure and the flow-load relationship.
3. The intelligent steam pressure control method of claim 1, wherein, Step S2 comprises: S21, setting an electrically-controlled regulating valve with an initial valve position close to 50% opening degree as the main valve; S22, actively regulating the main valve and controlling the secondary valve to be locked; until a secondary valve unlocking condition is met; wherein the secondary valve unlocking condition comprises main valve and secondary valve switching, downstream process sudden disturbance, main valve failure and main valve and secondary valve synchronization; S23, when the main valve and the secondary valve switching condition is met, changing the original main valve into the secondary valve and the original secondary valve into the main valve.
4. The intelligent steam pressure control method of claim 3, wherein, The main valve and the secondary valve switching condition is at least one of the following conditions: Main valve instruction or feedback failure; Main valve instruction and feedback deviation greater than a first percentage; Main steam pressure total failure; Main steam pressure and set deviation greater than a first pressure value; Main valve jump deviation greater than a second percentage; Main valve and secondary valve difference deviation greater than a third percentage.
5. The intelligent steam pressure control method of claim 1, wherein, Step S3 comprises: regulating the steady-state pressure of the main valve through PID control according to set parameters; and combining real-time pressure feedback to correct the main valve action amount through main valve PID output to form a closed-loop control; Wherein, the set parameters of the PID are obtained through the following steps: S031, confirming that the regulating valve mechanical structure is normal and the system is in a stable state; S032, setting initial parameters; S033, inputting a closed-loop control, inputting a step signal and recording a process curve; S034, observing whether the system response is stable; when the system response is not stable, adjusting the initial parameters until the system is stable; S035, checking oscillation and adjusting integral time and / or differential time when overshoot occurs; S036, evaluating whether performance indicators meet the conditions; when the performance indicators do not meet the conditions, repeating steps S033 to S035; until the performance indicators meet the conditions; S037, recording the adjusted parameters as the set parameters.
6. The intelligent steam pressure control method of claim 1, wherein, Step S5 comprises the following steps: Every second set time, detecting a double-valve opening degree deviation; when the deviation of the two is greater than a fourth percentage, triggering a synchronization instruction.
7. The intelligent steam pressure control method of claim 1, wherein, When a load mutation rate is greater than a set change rate, controlling the secondary valve to start feedforward compensation and adjusting the secondary valve opening degree to a fifth percentage of a target value.
8. The intelligent steam pressure control method of claim 7, wherein, The pre-compensation signal of the feedforward compensation is generated by a preset model based on a steam turbine DEH frequency modulation principle.
9. The intelligent steam pressure control method of any one of claims 1-8, wherein, When any electric regulating valve fails, the other electric regulating valve is switched to wide-range regulating mode to maintain system stability by extending the regulating range of the electric regulating valve, and to prevent the pressure transient peak from exceeding the safety threshold during load rejection according to the preset valve position dynamic limiting curve.
10. The intelligent steam pressure control method of claim 9, wherein, In wide-range regulating mode, the minimum value among the main valve opening command, the upper limit of valve position output, and the zero position of the pressure reducing valve interlock is taken as the actual output command of the regulating valve to control the electric regulating valve.