Accurate diagnosis method and system for follow-up fault of guide vane of water turbine governor

Abstract

The invention provides a hydraulic turbine governor guide vane follow-up fault accurate diagnosis method, and relates to the technical field of governor, and the method comprises the steps: monitoring the state of a unit which comprises a governor guide vane; when the guide vane deviation is larger than a first threshold value, the guide vane action speed is smaller than a second threshold value, the guide vane opening degree is larger than a third threshold value, the servo valve follow-up fault and the main and auxiliary follow-up fault do not exist, and time delay exists, it is determined that the guide vane follow-up fault occurs; when the guide vane follow-up fault occurs, whether the unit has the risk of overload or phase modulation operation or not is predicted based on the unit power, the guide vane opening degree and whether the enabling soft pressing plate is input or not, if yes, the unit is shut down, a host is switched, and if not, the unit is kept running, and manual control is switched. By the adoption of the scheme, precise diagnosis and fault processing of the speed regulator guide vane follow-up fault are achieved.

Description

Technical Field

[0001] This application relates to the technical field of governors, and particularly to a precise diagnosis method and system for the servo-following fault of the guide vane of a hydraulic turbine governor. Background Art

[0002] At present, the logic of the servo-following fault of the guide vane of the governor in a hydropower plant is simple and cannot perform precise diagnosis. Manual participation is required, which easily leads to misoperation and refusal to operate of the equipment, causing serious equipment damage and economic losses. Summary of the Invention

[0003] This application aims to solve at least one of the technical problems in the related art to some extent.

[0004] To this end, the first object of this application is to propose a precise diagnosis method for the servo-following fault of the guide vane of a hydraulic turbine governor, which realizes the precise diagnosis and fault handling of the servo-following fault of the guide vane of the governor.

[0005] The second object of this application is to propose a precise diagnosis system for the servo-following fault of the guide vane of a hydraulic turbine governor.

[0006] To achieve the above object, the first aspect embodiment of this application proposes a precise diagnosis method for the servo-following fault of the guide vane of a hydraulic turbine governor, including: monitoring the unit state, where the unit includes the guide vane of the governor; when the guide vane deviation is greater than the first threshold, the guide vane action rate is less than the second threshold, the guide vane opening is greater than the third threshold, there is no servo valve servo-following fault and main distributor servo-following fault and there is a time delay, it is determined that a guide vane servo-following fault occurs; when a guide vane servo-following fault occurs, based on whether the unit power, the guide vane opening and the enable soft pressure plate are input, it is predicted whether there is a risk of overload or phase modulation operation of the unit. If there is, the unit is shut down and the main machine is switched. If not, the unit is kept running and switched to manual control.

[0007] To achieve the above object, the second aspect embodiment of this invention proposes a precise diagnosis system for the servo-following fault of the guide vane of a hydraulic turbine governor, including: a state monitoring module for monitoring the unit state, where the unit includes the guide vane of the governor; a fault diagnosis module for determining that a guide vane servo-following fault occurs when the guide vane deviation is greater than the first threshold, the guide vane action rate is less than the second threshold, the guide vane opening is greater than the third threshold, there is no servo valve servo-following fault and main distributor servo-following fault and there is a time delay; the fault diagnosis module is further used to predict whether there is a risk of overload or phase modulation operation of the unit based on the unit power, the guide vane opening and whether the enable soft pressure plate is input when a guide vane servo-following fault occurs; a fault handling module for shutting down the unit and switching the main machine when there is a risk of overload or phase modulation operation, and keeping the unit running and switching to manual control when there is no risk of overload or phase modulation operation.

[0008] The precise diagnosis method and system for the servomotor failure of the guide vane of a hydraulic turbine governor in the embodiments of the present application monitor the unit status to accurately determine the servomotor failure of the guide vane. At the same time, when the servomotor failure of the guide vane is reported, the load shedding self-check and overload self-check are performed to determine whether the unit has the risk of entering the phase modulation operation and overload operation. The embodiments achieve the all-round and non-blind-spot detection of the servomotor failure of the guide vane, greatly improve the reliability of the governor, and effectively avoid damage to the generator.

[0009] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present application. Description of the Drawings

[0010] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description of the embodiments in conjunction with the drawings, in which:

[0011] Figure 1 is a schematic flow chart of a precise diagnosis method for the servomotor failure of the guide vane of a hydraulic turbine governor provided in the first embodiment of the present application;

[0012] Figure 2 is a schematic structural diagram of a precise diagnosis system for the servomotor failure of the guide vane of a hydraulic turbine governor provided in the embodiments of the present application. Detailed Embodiments

[0013] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the drawings, in which the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, but should not be construed as limiting the present application.

[0014] The precise diagnosis method and system for the servomotor failure of the guide vane of a hydraulic turbine governor in the embodiments of the present application will be described below with reference to the drawings.

[0015] Figure 1 is a schematic flow chart of a precise diagnosis method for the servomotor failure of the guide vane of a hydraulic turbine governor provided in the first embodiment of the present application.

[0016] As Figure 1 shown, the precise diagnosis method for the servomotor failure of the guide vane of a hydraulic turbine governor includes the following steps:

[0017] Step 101, monitor the unit status, where the unit includes the guide vane of the governor;

[0018] Step 102, when the guide vane deviation is greater than the first threshold, the guide vane action rate is less than the second threshold, the guide vane opening is greater than the third threshold, there is no servo valve follow-up failure and main distribution follow-up failure, and there is a time delay, it is determined that a guide vane follow-up failure occurs;

[0019] In this embodiment, a guide vane displacement sensor is used to measure the position change of the governor guide vane.

[0020] In this embodiment, the judgment logic for the guide vane follow-up fault is as follows: when there is no abnormal alarm such as sampling disconnection or jump in the guide vane displacement sensor, if the guide vane deviation > 5% (i.e., |guide vane setting - guide vane feedback| > 5%), the guide vane action rate < 0.75% / s, the guide vane opening > 13%, with a delay of 1.5 s and no servo valve follow-up fault and no main distributor follow-up fault, then report the guide vane follow-up fault.

[0021] In this embodiment, the judgment logic for the servo valve follow-up fault is: (|guide vane setting - guide vane feedback| > 5%) && (|control output - servo valve feedback| > 0.48 mA) && with a delay of 1.5 s, then report the servo valve follow-up fault; the judgment logic for the main distributor follow-up fault is: (|guide vane setting - guide vane feedback| > 5%) && {(when opening the guide vane, the main distributor feedback < -1.2 mA) || (when closing the guide vane, the main distributor feedback > 1.2 mA)} && with a delay of 1.5 s, then report the main distributor follow-up fault.

[0022] Through the guide vane follow-up fault judgment logic, a series of hidden problems such as guide vane jamming, unsmooth hydraulic circuit, hydraulic pipeline bursting, and insufficient operating power of the servomotor can be effectively detected.

[0023] Step 103, when a guide vane follow-up fault occurs, based on the unit power, guide vane opening, and whether the enabling soft pressure plate is engaged, predict whether there is a risk of overload or phase modulation operation of the unit. If so, stop the unit and switch the main engine; if not, keep the unit running and switch to manual control.

[0024] Based on the above guide vane follow-up fault judgment logic, if the servo valve spool or the main distributor valve spool is stuck in the middle position and does not reach the alarm threshold of the servo valve and the main distributor valve, neither the servo valve follow-up fault nor the main distributor follow-up fault will be reported, and the guide vane servomotor will continue to act. If the proportional servo valve spool or the main distributor valve spool is stuck in the partially open direction, the guide vane servomotor will continuously open the guide vane, which is likely to cause overload of the unit; if the proportional servo valve spool or the main distributor valve spool is stuck in the partially closed direction, the guide vane servomotor will continuously close the guide vane, which is likely to cause phase modulation operation of the unit, resulting in serious consequences.

[0025] Based on the above problems, when the guide vane follow-up fault is reported, it is necessary to predict whether there is a risk of overload or phase modulation operation of the unit. Therefore, based on the guide vane follow-up fault logic, a logical judgment is made again:

[0026] (1) Overload self-check: When a governor guide vane following failure occurs, if the proportional servo valve or the main distribution valve core is stuck in the closing direction, and the servo valve following failure and the main distribution following failure cannot be reported, the guide vane will continue to close until the guide vane is fully closed and the unit is in phase adjustment operation. The guide vane following failure accurate diagnosis method can accurately diagnose the guide vane following failure by judging the guide vane opening, and quickly shut down the unit to prevent the unit from entering phase adjustment operation and avoid causing greater damage to the turbine generator.

[0027] Judgment logic: If the guide vane follower fault is reported, and the power is greater than 112% Pr and the soft pressure plate is enabled, a shutdown fault will be triggered and the host will be switched.

[0028] (2) Load slip self-check: When the governor guide vane follow-up failure occurs, if the proportional servo valve or the main distribution valve core is stuck in the open direction, and the servo valve follow-up failure and the main distribution follow-up failure cannot be reported, the guide vane will continue to open until the guide vane is fully open. If the water head is high, the unit output can reach 800MW or more, causing the unit to be overloaded and bring serious impact to the generator. Through the accurate diagnosis method of the guide vane follow-up failure, the guide vane follow-up failure can be accurately diagnosed by judging the unit output, and the unit can be shut down quickly to prevent the unit from overloading and avoid causing greater damage to the generator.

[0029] Judgment logic: If the guide vane follow-up fault is reported, and the guide vane opening is less than 5% and the soft pressure plate is enabled, a shutdown fault will be triggered and the host will be switched.

[0030] When the servo valve core or the main pressure regulating valve core is stuck in the middle position and the servo valve and main pressure regulating valve alarm thresholds are not reached, and the guide vane deviation is greater than 5%, a guide vane follow-up fault will be reported. In order to reduce the impact on the grid load, when the guide vane follow-up fault is reported, the controller switches the host and switches to manual control without shutting down. If the guide vane continues to move, once one of the two logics (1) and (2) is met, a shutdown fault will be triggered and the unit will shut down to prevent the unit from overloading or phase adjustment operation.

[0031] The accurate diagnosis method of the turbine governor guide vane follow-up fault in the embodiment of the present application combines the guide vane deviation, guide vane opening and other signals to judge the guide vane follow-up fault. On this basis, it combines the guide vane opening, unit power and other signals to accurately detect whether the guide vane is stuck when the guide vane follow-up fault logic is reported. This embodiment has the characteristics of simplicity, reliability, accurate judgment, and no monitoring blind spots, and realizes all-round and dead-angle detection of guide vane follow-up faults, reduces the risk of unit overload or phase adjustment operation, reduces accident hazards, and greatly improves the reliability of the governor.

[0032] In order to implement the above-mentioned embodiment, the present application also proposes a precise diagnosis system for turbine governor guide vane follow-up faults.

[0033] Figure 2 This is a schematic structural diagram of a precise diagnosis system for the servomotor fault of the guide vane of a hydraulic turbine governor provided by an embodiment of the present application.

[0034] As Figure 2 shown, the precise diagnosis system for the servomotor fault of the guide vane of the hydraulic turbine governor includes:

[0035] A status monitoring module for monitoring the status of the unit, where the unit includes a governor guide vane;

[0036] A fault diagnosis module for determining that a guide vane servomotor fault occurs when the guide vane deviation is greater than a first threshold, the guide vane action rate is less than a second threshold, the guide vane opening is greater than a third threshold, there is no servovalve servomotor fault and no main distributor servomotor fault, and there is a time delay;

[0037] The fault diagnosis module is further configured to, when a guide vane servomotor fault occurs, predict whether there is a risk of overload or phase modulation operation of the unit based on the unit power, the guide vane opening, and whether the enabling soft pressure plate is engaged;

[0038] A fault handling module for shutting down the unit and switching the main machine when there is a risk of overload or phase modulation operation, and keeping the unit running and switching to manual control when there is no risk of overload or phase modulation operation.

[0039] Further, in the embodiment of the present application, monitoring the status of the governor guide vane includes:

[0040] Using a guide vane displacement sensor to measure the position change of the governor guide vane, and repairing the abnormality when the guide vane displacement sensor is abnormal, where the abnormality includes sampling disconnection and jump.

[0041] Specifically, in the embodiment of the present application, the guide vane deviation calculation formula is: guide vane deviation = |guide vane given - guide vane feedback|, the first threshold is 5%, the second threshold is 0.75% / s, the third threshold is 13%, and the existence of time delay is 1.5 s of time delay.

[0042] Further, in the embodiment of the present application, the judgment logic for the servovalve servomotor fault is:

[0043] When the guide vane deviation is greater than 5%, |control output - servovalve feedback| > 0.48 mA, and the time delay is 1.5 s, it is determined that a servovalve servomotor fault occurs;

[0044] The judgment logic for the main distributor servomotor fault is:

[0045] When the guide vane deviation is greater than 5%, (when opening the guide vane, the main distributor feedback < -1.2 mA) || (when closing the guide vane, the main distributor feedback > 1.2 mA), and the time delay is 1.5 s, it is determined that a main distributor servomotor fault occurs.

[0046] Specifically, in the embodiments of the present application, predicting whether there is a risk of overload or phase modulation operation of the unit based on the unit power, the guide vane opening, and whether the enabling soft pressure plate is engaged includes:

[0047] If the unit power is greater than 112% Pr and the enabling soft pressure plate is engaged, it is predicted that there is a risk of overload for the unit;

[0048] If the guide vane opening is less than 5% and the enabling soft pressure plate is engaged, it is predicted that there is a risk of phase modulation operation for the unit.

[0049] It should be noted that the foregoing explanation of the embodiments of the precise diagnosis method for the guide vane follow-up fault of the hydraulic turbine governor also applies to the precise diagnosis system for the guide vane follow-up fault of the hydraulic turbine governor in this embodiment, and will not be elaborated here.

[0050] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0051] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" can explicitly or implicitly include at least one of these features. In the description of the present application, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0052] Any process or method description shown in the flowchart or described in other ways herein can be understood as representing a module, segment, or part of code including one or more executable instructions for implementing a customized logical function or process, and the scope of the preferred embodiments of the present application includes additional implementations, where the functions can be executed in a manner that is not shown or discussed in sequence, including in a substantially simultaneous manner or in a reverse order according to the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0053] The logic and / or steps represented in the flowchart or otherwise described herein can, for example, be considered as a definable sequence list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or used in combination with these instruction execution systems, apparatus, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in combination with an instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: electrical connection parts with one or more wirings (electronic devices), portable computer disk cartridges (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber devices, and portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpretation, or other suitable processing as necessary, and then stored in a computer memory.

[0054] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application-specific integrated circuits having suitable combinational logic gate circuits, programmable gate arrays (PGA), field programmable gate arrays (FPGA), etc.

[0055] Those of ordinary skill in the art of this technology can understand that all or part of the steps carried by the method of implementing the above embodiments can be completed by instructing relevant hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments.

[0056] In addition, in each embodiment of the present application, each functional unit can be integrated into a processing module, or each unit can exist physically alone, or two or more units can be integrated into one module. The above-mentioned integrated module can be implemented in the form of hardware or in the form of a software functional module. When the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0057] The above-mentioned storage medium can be a read-only memory, a magnetic disk or an optical disc, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A method for accurately diagnosing a turbine governor guide vane follower fault, characterized in that: include: monitoring the status of a unit, wherein the unit includes a governor guide vane; When the guide vane deviation is greater than the first threshold, the guide vane action rate is less than the second threshold, the guide vane opening is greater than the third threshold, there is no servo valve follow-up fault and main distribution follow-up fault and there is a delay, it is determined that a guide vane follow-up fault occurs; When a guide vane follow-up failure occurs, based on the unit power, guide vane opening and whether the enabling soft pressure plate is in operation, it is predicted whether the unit is at risk of overload or phase adjustment operation. If so, the unit is shut down and the main engine is switched. If not, the unit is kept running and switched to manual control.

2. The method according to claim 1, characterized in that Monitor the status of the governor guide vanes, including: A guide vane displacement sensor is used to measure the position change of the governor guide vane, and when an abnormality occurs in the guide vane displacement sensor, the abnormality is repaired, wherein the abnormality includes sampling disconnection and jump.

3. The method according to claim 1, characterized in that The guide vane deviation calculation formula is: guide vane deviation = |Guide vane setting-guide vane feedback|, the first threshold is 5%, the second threshold is 0.75% / s, the third threshold is 13%, and the existence delay is 1.5s.

4. The method according to claim 1, characterized in that The judgment logic of the servo valve follow-up failure is: When the guide vane deviation is greater than 5%, |control output - servo valve feedback|>0.48mA and the delay is 1.5s, it is determined that the servo valve follow-up fault occurs; The judgment logic of the main and auxiliary follower fault is: When the guide vane deviation is greater than 5%, (main distribution feedback <-1.2mA when opening the guide vane)||(main distribution feedback >1.2mA when closing the guide vane) and the delay is 1.5s, it is determined that a main distribution follow-up fault has occurred.

5. The method according to claim 1, characterized in that The prediction of whether the unit has the risk of overload or phase adjustment operation based on the unit power, guide vane opening and whether the soft pressure plate is enabled is put into use includes: If the unit power is greater than 112% Pr and the soft pressure plate is enabled, it is predicted that the unit is at risk of overload; If the guide vane opening is less than 5% and the soft pressure plate is enabled, it is predicted that the unit is at risk of phase adjustment operation.

6. A precise diagnosis system for turbine governor guide vane follow-up fault, characterized in that: include:. A state monitoring module, used for monitoring the state of the unit, wherein the unit includes a governor guide vane; A fault diagnosis module is used to determine that a guide vane following fault occurs when the guide vane deviation is greater than a first threshold, the guide vane action rate is less than a second threshold, the guide vane opening is greater than a third threshold, there is no servo valve following fault and main distribution following fault, and there is a delay; The fault diagnosis module is also used to predict whether the unit has a risk of overload or phase adjustment operation based on the unit power, guide vane opening and whether the soft pressure plate is enabled when a guide vane follow-up fault occurs; The fault handling module is used to shut down the unit and switch the main engine when there is a risk of overload or phase adjustment operation, and to keep the unit running and switch to manual control when there is no risk of overload or phase adjustment operation.

7. The device according to claim 6, characterized in that Monitor the status of the governor guide vanes, including: A guide vane displacement sensor is used to measure the position change of the governor guide vane, and when an abnormality occurs in the guide vane displacement sensor, the abnormality is repaired, wherein the abnormality includes sampling disconnection and jump.

8. The device according to claim 6, characterized in that The guide vane deviation calculation formula is: guide vane deviation = |Guide vane setting-guide vane feedback|, the first threshold is 5%, the second threshold is 0.75% / s, the third threshold is 13%, and the existence delay is 1.5s.

9. The device according to claim 6, characterized in that The judgment logic of the servo valve follow-up failure is: When the guide vane deviation is greater than 5%, |control output - servo valve feedback|>0.48mA and the delay is 1.5s, it is determined that the servo valve follow-up fault occurs; The judgment logic of the main and auxiliary follower fault is: When the guide vane deviation is greater than 5%, (main distribution feedback <-1.2mA when opening the guide vane)||(main distribution feedback >1.2mA when closing the guide vane) and the delay is 1.5s, it is determined that a main distribution follow-up fault has occurred.

10. The device according to claim 6, characterized in that The prediction of whether the unit has the risk of overload or phase adjustment operation based on the unit power, guide vane opening and whether the soft pressure plate is enabled is put into use includes: If the unit power is greater than 112% Pr and the soft pressure plate is enabled, it is predicted that the unit is at risk of overload; If the guide vane opening is less than 5% and the soft pressure plate is enabled, it is predicted that the unit is at risk of phase adjustment operation.

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