Guide vane feedback fault judgment method
By configured three sets of guidelines feedback signals and comparison differences, the problem of inaccurate judgment of the guidance feedback signal fault in the existing technologies has been solved. Power generation reliability.
Patent Information
- Application Number
- CN202411657492.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-20
- Publication Date
- 2025-01-28
AI Technical Summary
The prior art is difficult to accurately judge the fault between the feedback signals of the guide vane, which leads to the inability to switch to the backup sensor in time, which may lead to serious consequences such as loss of control of the guide vane and unit power fluctuations.
The comparison difference is judged by the three sets of leaf feedback signals. By setting the difference door limit value ε1, the three sets of signal differences in real -time comparison, judge the fault cover and switch to the backup signal to ensure the normal operation of the system.
The accurate judgment and timely processing of the feedback failure of the guidance leaf, improved the reliability of the power generation of the water wheel generator set, and avoided problems such as the out of control and the power fluctuations of the crew.
Smart Images
Figure CN119373648A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of power signal detection, and in particular relates to a guide vane feedback fault judgment method. Background Art
[0002] In a turbine's speed governor control system, the guide vane feedback signal is the most critical measurement component. Typically, the speed governor control system is equipped with two sets of guide vane feedback signals, serving as primary and backup. Under normal circumstances, one set serves as the primary signal. If the primary guide vane feedback signal fails, the system automatically switches to the backup signal. If both sets of guide vane feedback signals fail, the speed governor control system will indicate a critical fault and cease operation.
[0003] The source of the guide vane feedback signal is the relay displacement sensor. Common displacement sensors include rope-type displacement sensors and magnetostrictive displacement sensors, which are specifically used to monitor and control the opening changes of the turbine guide vanes, convert mechanical displacement into electrical signal output, and send it to the speed regulator electrical control cabinet to achieve precise control and adjustment of the turbine speed control system.
[0004] The guide vane feedback fault judgment logic mainly detects whether the guide vane feedback signal channels and hardware are normal: speed regulator PLC analog module fault or feedback channel fault or speed regulator management module fault.
[0005] The speed regulator electric control panel usually has two sets of PLCs, A and B, to process the guide vane feedback signal.
[0006] The conventional speed governor feedback judgment method is that the two sets of guide vane feedback signals are in a master-slave relationship. If a mechanical failure occurs in the connection between the main guide vane displacement sensor and the relay, such as the wire rope of the pull rope displacement sensor is stuck and knotted, the wire rope is not sensitive to extension and retraction, or the fixed steel plate of the magnetostrictive displacement sensor is broken, the nut falls off, or the connecting screw is broken, the measurement channel of the guide vane displacement sensor is fault-free at this time; the "fault-free" here means that there is a fault in these cases, but the conventional judgment method only detects the measurement channel, and no abnormality is found in the measurement channel. The speed governor electronic control panel cannot judge this type of error signal, resulting in the calculation result of the speed governor control system being an erroneous value, and the guide vane feedback signal cannot be switched to the backup sensor, which may lead to serious consequences such as guide vane loss of control and unit power fluctuation. Summary of the Invention
[0007] To address the problem of inability to accurately determine faults by comparing two sets of guide vane feedback signals, the present invention proposes a guide vane feedback fault diagnosis method that optimizes guide vane fault diagnosis. This method uses a method for comparing differences when configuring three sets of guide vane feedback signals to determine the faulty set. The method also systematically develops the judgment logic and method for the three sets of guide vane feedback signals. This method is implemented using the following technical solutions.
[0008] A guide vane feedback fault judgment method is used to check the guide vane feedback information of a turbine governor control system. The judgment method uses the feedback signals sent to the feedback channel by three guide vane displacement sensors to determine whether the guide vane feedback mechanism has a fault. The governor electric control panel is usually controlled by two PLCs, A and B. The two PLCs have a master-slave relationship and can be switched manually or automatically in the event of a fault. Their programs are completely consistent. Taking governor PLC A as the master as an example, the judgment method includes the following steps: Step 1: Set the first set of guide vane feedback signals Y1 as the main one, then set the second guide vane feedback signals Y2 and the third guide vane feedback signals Y3; Step 2: Set the difference threshold ε1 according to the type of the hydro-generator set, and compare the differences of the three guide vane feedback signals in real time. △Y1 is the absolute value of the difference between the first guide vane feedback signal Y1 and the second guide vane feedback signal Y2, △Y2 is the absolute value of the difference between the second guide vane feedback signal Y2 and the third guide vane feedback signal Y3, and △Y3 is the absolute value of the difference between the third guide vane feedback signal Y3 and the first guide vane feedback signal Y1. Step 3: Determine whether the feedback signal Y1 of the first guide vane is normal. If Y1 is normal, Y1 is used as the primary function. If Y1 is abnormal and Y2 and Y3 are normal, compare △Y2 with ε1. If △Y2 is less than ε1, Y2 is used as the primary function. If △Y2 is greater than or equal to ε1, the speed governor reports "A set fault", and PLC A withdraws from the primary function, and PLC B becomes the primary function. Step 4: When the first set of guide vane feedback signal Y1 is normal, determine whether Y2 and Y3 are normal. If both Y2 and Y3 are abnormal, the speed governor reports "A set fault", and PLC A withdraws from the master role, with PLC B taking over as the master role. When both Y2 and Y3 are normal, compare △Y1, △Y2, and △Y3, and proceed to step 5. When either Y2 or Y3 is normal, compare △Y1 and △Y3, and proceed to step 6. Step 5: When both Y2 and Y3 are normal, if △Y1<ε1, △Y2<ε1, △Y3<ε1, Y1 is the main controller and operates normally; if △Y1>ε1, △Y2>ε1, △Y3>ε1, the speed governor reports "A set fault", A set PLC withdraws from the master right, and B set PLC takes the main role; if △Y1>ε1, △Y2<ε1, △Y3<ε1, the speed governor reports "the first set of guide vane feedback signal Y1 asynchronous fault", and switches to Y2 as the main controller; if △Y1<ε1, △Y2>ε1, △Y3>ε1, the speed governor reports "the third set of guide vane feedback signal Y3 asynchronous fault", and Y1 remains the main controller; if △Y1>ε1, △Y2>ε1, △Y3<ε1, the speed governor reports "the third set of guide vane feedback signal Y3 asynchronous fault", and Y1 remains the main controller; Step 6: When one of Y2 and Y3 is normal, if △Y1<ε1 or △Y3<ε1, Y1 will still be the primary controller; if △Y1>ε1 and △Y3>ε1, the speed controller will report "A set fault", and PLC A will quit the primary controller, and PLC B will be the primary controller. Step 7: The speed regulator B set PLC is used as the main one and has the same control logic. When both A and B sets fail, the speed regulator reports "serious failure" and exits control.
[0009] The present invention has the following major beneficial technical effects: It utilizes a "two out of three" judgment logic, taking into account various operating conditions, to form a guide vane feedback judgment process, which plays a key role in accurately identifying guide vane feedback faults in the governor and promptly addressing them. The present judgment method is comprehensive and highly applicable, significantly improving the power generation reliability of hydro-turbine generator sets. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 This is a block diagram of the judgment principle of the present invention. DETAILED DESCRIPTION
[0011] In order to enable those skilled in the art to better understand and implement this patent, the specific implementation methods of this application are now described in detail in conjunction with the drawings in the specification.
[0012] Please see Figure 1 A guide vane feedback fault diagnosis method is used to check the guide vane feedback information of a turbine governor control system. The method uses the feedback signals sent to the feedback channel by three sets of guide vane displacement sensors to determine whether the guide vane feedback mechanism has a fault. Taking governor PLC set A as the main one as an example, the judgment method includes the following steps: Step 1: Set the first set of guide vane feedback signals Y1 as the main one, then set the second guide vane feedback signals Y2 and the third guide vane feedback signals Y3; Step 2: Set the difference threshold ε1 according to the type of the hydro-generator set, and compare the differences of the three guide vane feedback signals in real time. △Y1 is the absolute value of the difference between the first guide vane feedback signal Y1 and the second guide vane feedback signal Y2, △Y2 is the absolute value of the difference between the second guide vane feedback signal Y2 and the third guide vane feedback signal Y3, and △Y3 is the absolute value of the difference between the third guide vane feedback signal Y3 and the first guide vane feedback signal Y1. Step 3: Determine whether the feedback signal Y1 of the first guide vane is normal. If Y1 is normal, Y1 is used as the primary function. If Y1 is abnormal and Y2 and Y3 are normal, compare △Y2 with ε1. If △Y2 is less than ε1, Y2 is used as the primary function. If △Y2 is greater than or equal to ε1, the speed governor reports "A set fault", and PLC A withdraws from the primary function, and PLC B becomes the primary function. Step 4: When the first set of guide vane feedback signal Y1 is normal, determine whether Y2 and Y3 are normal. If both Y2 and Y3 are abnormal, the speed governor reports "A set fault", and PLC A withdraws from the master role, with PLC B taking over as the master role. When both Y2 and Y3 are normal, compare △Y1, △Y2, and △Y3, and proceed to step 5. When either Y2 or Y3 is normal, compare △Y1 and △Y3, and proceed to step 6. Step 5: When both Y2 and Y3 are normal, if △Y1<ε1, △Y2<ε1, △Y3<ε1, Y1 is the main controller and operates normally; if △Y1>ε1, △Y2>ε1, △Y3>ε1, the speed governor reports "A set fault", A set PLC withdraws from the master right, and B set PLC takes the main role; if △Y1>ε1, △Y2<ε1, △Y3<ε1, the speed governor reports "the first set of guide vane feedback signal Y1 asynchronous fault", and switches to Y2 as the main controller; if △Y1<ε1, △Y2>ε1, △Y3>ε1, the speed governor reports "the third set of guide vane feedback signal Y3 asynchronous fault", and Y1 remains the main controller; if △Y1>ε1, △Y2>ε1, △Y3<ε1, the speed governor reports "the third set of guide vane feedback signal Y3 asynchronous fault", and Y1 remains the main controller; Step 6: When one of Y2 and Y3 is normal, if △Y1<ε1 or △Y3<ε1, Y1 will still be the primary controller; if △Y1>ε1 and △Y3>ε1, the speed controller will report "A set fault", and PLC A will quit the primary controller, and PLC B will be the primary controller. Step 7: The control logic of speed regulator B set PLC as the master is exactly the same as the above six steps. When both A and B sets have serious faults that cause them to exit the master right, the speed regulator reports "serious fault" and exits control.
[0013] The key points of this application are: (1) Accurately identify the faults of the guide vane feedback signal and eliminate the faults, thus reducing the number of unit shutdowns caused by governor failures and improving the power generation reliability of the hydro-generator unit.
[0014] (2) It has strong applicability and this judgment logic and process can be used in all hydro-turbine generator sets.
[0015] (3) Easy to operate and simple to use.
[0016] According to national standards, after the adjustment process stabilizes, the deviation between the actual opening of the relay and the given value Yset should be within the range of -0.4%Yr~0.4%Yr.
[0017] Before implementing the present invention, the applicant randomly retrieved 100 values from October 2022 to March 2023. Among them, 79 values of generator set No. 3 met the deviation requirements, and 21 exceeded the standard; among generator set No. 4, 86 values met the deviation requirements, and 14 exceeded the standard.
[0018] To this end, after demonstration and implementation, the applicant adopted the relay displacement sensor feedback method for measuring the guide vane opening of the speed governor of units 3 and 4, and changed the two sets of displacement sensor wire ropes of the speed governor to three sets of magnetostrictive guide vane feedback displacement sensors. The speed governor waterless test was normal, which was used to realize the switching of dual sets of feedback redundancy; and the method in this application was implemented to ensure the safe and stable operation of the unit speed governor.
[0019] One guide vane feedback signal, Y1, is used as the primary signal, followed by the second, Y2. The third, Y3, is used for comparison with the other two feedback signals. Controllers A and B use these three guide vane signals as triple-redundant information and perform a two-out-of-three logic decision. The threshold value is ε1 (configurable on the touchscreen), and △Y1, △Y2, and △Y3 are the pairwise differences between the three signals. After the countermeasure was implemented, the actual openings of units 3 and 4 deviated from the setpoint by 100%.
[0020] This invention belongs to the field of hydroturbine governor control systems, specifically to a guide vane feedback judgment logic method and process. This invention utilizes a "two out of three" judgment logic, taking into account various operating conditions, to develop a guide vane feedback judgment process. This process plays a key role in accurately identifying and promptly addressing guide vane feedback failures in the governor. The invention is comprehensive and highly applicable, significantly improving the power generation reliability of hydroturbine generator sets.
[0021] The above embodiments are merely preferred technical solutions of the present invention and should not be construed as limiting the present invention. The scope of protection of the present invention shall be the technical solutions described in the claims, including equivalent alternatives to the technical features of the technical solutions described in the claims. Equivalent alternatives and improvements within this scope are also within the scope of protection of the present invention.
Claims
1. A guide vane feedback fault judgment method is used for checking the guide vane feedback information of a turbine governor control system. The judgment method uses the feedback signals sent by three sets of guide vane displacement sensors to the feedback channel to judge whether the guide vane feedback mechanism has a fault. Taking the governor A set of PLC as the main one as an example, the judgment method includes the following steps: Step 1: Set the first set of guide vane feedback signals Y1 as the main one, and then set the second guide vane feedback signals Y2 and the third guide vane feedback signals Y3; Step 2: Set the difference threshold ε1 according to the type of the hydro-generator set, and compare the difference of the three guide vane feedback signals in real time. △Y1 is the absolute value of the difference between the first guide vane feedback signal Y1 and the second guide vane feedback signal Y2, △Y2 is the absolute value of the difference between the second guide vane feedback signal Y2 and the third guide vane feedback signal Y3, and △Y3 is the absolute value of the difference between the third guide vane feedback signal Y3 and the first guide vane feedback signal Y1; Step 3: Determine whether the feedback signal Y1 of the first set of guide vanes is normal. When the measured value of Y1 is normal, Y1 is used as the main function. When the measured value of Y1 is abnormal and the measured values of Y2 and Y3 are normal, compare △Y2 with ε1. If △Y2 is less than ε1, Y2 is used as the main function. If △Y2 is greater than or equal to ε1, the speed regulator reports "A set fault", and the A set PLC withdraws from the main function, and the B set PLC is used as the main function. Step 4: When the first set of guide vane feedback signal Y1 is normal, determine whether Y2 and Y3 are normal. When both Y2 and Y3 are abnormal, the governor reports "A set fault", and A set PLC withdraws from the main use right, and B set PLC takes the main use right; when Y2 and Y3 are normal, compare △Y1, △Y2, △Y3, and enter the fifth step; when one of Y2 and Y3 is normal, compare △Y1, △Y3, and enter the sixth step; Step 5: When both Y2 and Y3 are normal, if △Y1<ε1, △Y2<ε1, △Y3<ε1, Y1 is the main one and works normally; if △Y1>ε1, △Y2>ε1, △Y3>ε1, the speed regulator reports "A set fault", A set PLC withdraws from the main right, and B set PLC is the main one; if △Y1>ε1, △Y2<ε1, △Y3<ε1, the speed regulator reports "the first set of guide vane feedback signal Y1 asynchronous fault", and switches to Y2 as the main one; if △Y1<ε1, △Y2>ε1, △Y3>ε1, the speed regulator reports "the third set of guide vane feedback signal Y3 asynchronous fault", and Y1 is still the main one; if △Y1>ε1, △Y2>ε1, △Y3<ε1, the speed regulator reports "the third set of guide vane feedback signal Y3 asynchronous fault", and Y1 is still the main one; Step 6: When one of Y2 and Y3 is normal, if △Y1<ε1 or △Y3<ε1, Y1 is still the main one; if △Y1>ε1 and △Y3>ε1, the speed regulator reports "A set fault", and A set PLC withdraws from the main right, and B set PLC becomes the main one; Step 7: The speed regulator B set PLC is used as the main one with the same control logic. When both A and B sets fail, the speed regulator reports "serious failure" and exits control.