Speed ​​governor hydraulic follow-up system pilot valve - main and auxiliary follow-up fault diagnosis method

Abstract

A fault diagnosis method for the pilot valve-main pressure regulating valve of a speed governor hydraulic follow-up system is provided. The method includes a fault diagnosis system comprising a human-machine interface module, a controller, a stepper motor, a pilot valve, a main pressure regulating valve, and a relay. The controller is connected to the stepper motor, which in turn is connected to the pilot valve. The pilot valve is connected to the main pressure regulating valve, and the main pressure regulating valve is connected to the relay. The pilot valve is equipped with a first displacement sensor for measuring the position M of the pilot valve spool. 引 The main pressure regulating valve is equipped with a second displacement sensor to measure the valve core position M. 主 The relay is equipped with a third displacement sensor; the first, second, and third displacement sensors are all connected to the controller. This method is suitable for rapid and intelligent diagnosis and handling of hydraulic follow-up system faults such as intermittent jamming and failure to operate of actuators such as governor pilot valves, or oil leakage and pressure relief in the control oil circuit during grid-connected operation of the unit, thereby improving the accuracy and real-time performance of fault diagnosis.

Description

Technical Field

[0001] This invention relates to the field of hydraulic servo system technology for speed governors, and specifically to a fault diagnosis method for the pilot valve-main and auxiliary valve follower system of a hydraulic servo system for speed governors. Background Technology

[0002] Chinese patent "A Mid-Mount Automatic Intelligent Tuning System and Method for a Speed ​​Regulator Hydraulic Follow-up System" (Patent No.: ZL201910024102.X) discloses a speed regulator hydraulic follow-up system using a proportional valve and a main distributor / relay unit as the actuator. However, as a precision hydraulic component, the proportional valve has very high requirements for the quality of the hydraulic oil in the hydraulic system. Solid particulate impurities in the hydraulic oil may cause valve body jamming, thus affecting the normal operation of the speed regulator hydraulic follow-up system using the proportional valve as the electro-hydraulic conversion device. Therefore, it is necessary to research and explore a new speed regulator hydraulic follow-up system using a stepper motor and a pilot valve as the electro-hydraulic conversion and actuator.

[0003] If, during the normal operation and load regulation of a hydro-generator unit connected to the grid, the actuators such as the pilot valve, main pressure distribution valve, and servo valve malfunction and become intermittently stuck or fail to operate, or if the control oil circuit experiences oil leakage or pressure drop, and these malfunctions are not diagnosed and addressed in a timely manner, the unit load will be unable to be regulated normally, or even experience significant load fluctuations, seriously affecting the safe and stable operation of the unit and potentially causing an accidental shutdown.

[0004] Currently, among the publicly disclosed technical solutions in the field of fault diagnosis for hydraulic following systems of hydro-generator units:

[0005] Chinese patents such as "A method for judging the main connection and following fault of a giant turbine governor" (application number: 201710833464.4); "Intelligent diagnosis and processing method for faults in the main connection, main distribution and proportional valve hydraulic following system of governor" (application number: 201910024087.9); and "Intelligent diagnosis and processing method for faults in the main distribution and proportional valve hydraulic following system of governor" (application number: 201910024104.9) all disclose methods for diagnosing faults in proportional valves, main distribution and main connection, but do not involve the diagnosis of following faults between the pilot valve and the main distribution, which will be referred to as the diagnosis of pilot valve-main distribution following faults below.

[0006] For speed governor hydraulic servo systems that use closed-loop control based on the position of the pilot valve core, timely fault diagnosis at the pilot valve stage at the front end of the hydraulic servo system is of great practical significance. Compared to fault diagnosis at the main distribution and main connection stages, it can detect faults earlier, prevent accidents from escalating, and allow for earlier initiation of fault handling procedures. Summary of the Invention

[0007] This invention provides a method for diagnosing faults in the pilot valve-main-distributor follow-up system of a governor hydraulic follow-up system. More specifically, it is a system and method that, under grid-connected operation, allows the governor controller to perform real-time automatic intelligent diagnosis and processing of pilot valve-main-distributor follow-up faults in the governor hydraulic follow-up system by measuring and collecting the positions of the pilot valve and main-distributor valve cores in real time. This method is applicable to hydropower units that use stepper motors, pilot valves, main-distributor valves, and relays as electro-hydraulic conversion and actuators. It aims to quickly and intelligently diagnose and process hydraulic follow-up system faults during grid-connected operation, such as intermittent jamming or failure to operate of actuators like the governor pilot valve, or oil leakage and pressure drop in the control oil circuit. This improves the accuracy and real-time nature of fault diagnosis, preventing accidents from escalating and causing problems such as abnormal load regulation or even significant load fluctuations.

[0008] The technical solution adopted in this invention is as follows:

[0009] A fault diagnosis method for the pilot valve-master-supplier follower system of a speed governor hydraulic servo system, including a closed-loop control method for the master-supplier-pilot valve, based on the given M position of the master-supplier valve spool. 给定 Feedback M of pilot valve spool position 引 The difference in value controls the displacement of the stepper motor, thereby controlling the position M of the pilot valve spool. 引 Main valve core position M 主 Follow the position M of the pilot valve spool 引 The mechanical negative feedback closed loop is realized.

[0010] When the valve core of the pilot valve moves downward, the P port and A port of the pilot valve are connected, and the Y end of the main pressure regulating valve is supplied with pressure oil. The valve core of the main pressure regulating valve moves downward, causing the valve sleeve of the pilot valve to move downward. When the valve core and valve sleeve of the pilot valve move to the same displacement, the P port and A port of the pilot valve are no longer connected. At this time, the mechanical following system enters a steady state.

[0011] When the valve core of the pilot valve moves upward, the T port and A port of the pilot valve are connected, and the Y end of the main pressure regulating valve is connected to pressureless return oil. The valve core of the main pressure regulating valve moves upward, causing the valve sleeve of the pilot valve to move upward. When the valve core and valve sleeve of the pilot valve move to the same displacement, the T port and A port of the pilot valve are no longer connected. At this time, the mechanical following system enters a steady state.

[0012] The main valve core position M was achieved. 主 Follow the position M of the pilot valve spool 引 The mechanical negative feedback closed loop.

[0013] Methods for troubleshooting faults in the pilot valve of the governor hydraulic follower system - main and auxiliary follower valve.

[0014] The criterion for pilot valve-main / supplier follower failure is: |M 引 -M主 |>△ and V M <V 标 And keep it for a time greater than T.

[0015] △ represents the standard characteristic value comparing the positional deviation of the pilot valve and the main pressure regulating valve core in the pilot valve-main pressure regulating valve follower fault criterion;

[0016] V 标 In the fault criterion of the pilot valve-main distribution valve, the movement speed of the main distribution valve core is compared with the standard characteristic value.

[0017] T represents the standard characteristic value of the condition holding time in the pilot valve-main-feeder follower fault criterion.

[0018] The fault diagnosis method for the pilot valve of the governor hydraulic follower system - main and auxiliary follower valve includes the following steps:

[0019] Step 1: Initialize the speed controller electronic control system, Δ, V 标 Assign initial values ​​to T;

[0020] The initial value of △ is determined as follows: When the governor guide vane opening is tested from 0 to 100% in a step test, i.e., the guide vane opening is given by Y. 给定 When it changes from 0 to 100%, throughout the entire process |M 引 -M 主 The maximum value of | is set to △1;

[0021] When the governor guide vane opening is tested from 100% to 0% in a step change, i.e., the guide vane opening is given by Y... 给定 When it changes from 100% to 0, throughout the entire process |M 引 -M 主 Set the maximum value of ︱ to △2; set the larger of △1 and △2 as the initial value of △.

[0022] V 标 Method for determining initial values:

[0023] When the speed governor performs a positive Δ magnitude step test on the main control position, i.e., when the main control position is given by M... 给定 When the value changes from 0 to Δ, during the entire process, |M 主 -M 主(上一周期) Let the maximum value of | / Δt be V. 标1 When the speed governor performs a negative Δ magnitude main control position step test, that is, when the main control position setpoint M... 给定 When the value changes from 0 to -Δ, during the entire process, |M 主 -M 主(上一周期) Let the maximum value of | / Δt be V. 标2 V 标1 and V 标2 The smaller value in is set as V. 标The initial value is Δt, which is the self-loop execution cycle of the controller 11 program.

[0024] Method for determining the initial value of T:

[0025] T is a positive integer multiple of Δt, and is usually determined based on the actual situation. The larger T is, the longer the fault diagnosis time is, and the easier it is to miss a diagnosis, but the less likely it is to be misdiagnosed; the smaller T is, the shorter the fault diagnosis time is, and the less likely it is to miss a diagnosis, but the more likely it is to be misdiagnosed.

[0026] Step 2: The governor's electronic control system acquires the guide vane position given Y input from the guide vane opening control module of the governor's hydraulic servo system in real time. 给定 Guide vane position feedback Y, output main and auxiliary position given M 给定 Main valve core position (feedback) M 主 Pilot valve spool position M 引 Data such as...

[0027] Step 3: Determine |M 引 -M 主 | Is it greater than the threshold △? If yes, proceed to step ④; if no, proceed to step ②.

[0028] Step 4: Calculate the main valve core position movement speed V M =|M 主 -M 主(上一周期) | / △t;

[0029] Step 5: Determine if |M 引 -M 主 |>△ and V M <V 标 And maintain this for a time greater than T. If yes, proceed to step 6; otherwise, proceed to step 2.

[0030] Step 6: Troubleshooting. If there is a backup speed controller (standby unit) and it is fault-free, switch to the backup speed controller (standby unit) and proceed to Step 2. If the backup speed controller (standby unit) is faulty or there is no backup speed controller (standby unit), switch to the manual control mode of the speed controller and proceed to Step 7.

[0031] Speed ​​governor controllers typically have three control modes: automatic, electric manual (EMT), and mechanical manual (MA). In automatic control mode, the speed governor controller uses PID closed-loop control to control the turbine guide vane opening. In EMT control mode, the speed governor controller uses EMT open-loop control to control the turbine guide vane opening. In MAMA control mode, the speed governor controller uses MAMT open-loop control to control the turbine guide vane opening.

[0032] Switching to manual mode specifically refers to switching to the manual control mode of the speed controller.

[0033] Step 7: If the fault is manually reset and the system switches to automatic control mode, proceed to Step 2.

[0034] The automatic control mode status specifically refers to the automatic control mode status of the speed controller.

[0035] The governor hydraulic follow-up system pilot valve - main and auxiliary follow-up fault diagnosis system includes:

[0036] Human-machine interface module, controller, stepper motor, pilot valve, main pressure regulating valve, relay;

[0037] The controller is connected to the stepper motor, which in turn is connected to the pilot valve. The pilot valve is connected to the main pressure regulating valve, which is then connected to the relay.

[0038] The pilot valve is equipped with a first displacement sensor for measuring the position M of the pilot valve spool. 引 ;

[0039] The main pressure regulating valve is equipped with a second displacement sensor to measure the valve core position M of the main pressure regulating valve. 主 ;

[0040] The relay is equipped with a third displacement sensor to measure the guide vane position Y;

[0041] The first displacement sensor, the second displacement sensor, and the third displacement sensor are all connected to the controller.

[0042] The controller will use the standard characteristic value Δ and the standard characteristic value V of the position deviation between the pilot valve and the main valve core in the fault judgment of the hydraulic follow-up system of the speed governor to compare the pilot valve-main valve core position deviation. 标 Parameters such as condition holding time standard characteristic value T, and speed governor control command input controller.

[0043] The controller collects status signals from the pilot valve, main pressure regulating valve, and relay through the first, second, and third displacement sensors. It processes various input signals in real time according to the control parameters and commands issued by the user through the human-machine interaction module, and outputs control signals to the pilot valve, main pressure regulating valve, and relay; as well as to the stepper motor.

[0044] The relay is connected to the hydro-generator set, which is equipped with a speed measuring device and a power transmitter. The speed measuring device and the power transmitter are connected to the controller.

[0045] This invention provides a fault diagnosis method for the pilot valve-main distributor follower system of a speed governor hydraulic follower system, with the following technical advantages:

[0046] 1) This invention can quickly and accurately diagnose pilot valve-main distribution faults, avoiding the escalation of accidents that could lead to problems such as the inability to properly regulate unit load or even significant load fluctuations.

[0047] 2) This invention, combined with existing technology, can clearly diagnose whether the fault in the hydraulic follower system is in the pilot valve, main distribution valve, or main connection valve.

[0048] 3) The present invention “Main valve core position M” 主 Follow the position M of the pilot valve spool 引 Compared with traditional electrical negative feedback closed loops, the mechanical negative feedback closed loop has fewer intermediate links, no electrical links, simpler and more compact structure, better speed performance, and higher reliability. Attached Figure Description

[0049] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0050] Figure 1 This is a schematic diagram of the fault diagnosis system for the guide valve-main and auxiliary follower valve of the hydraulic follower system of the speed controller in this invention.

[0051] Figure 2 This is a schematic diagram of the closed-loop control structure of the electronic control system of the present invention.

[0052] Figure 3 A schematic diagram of the mechanical structure of the hydraulic servo system of the speed governor;

[0053] Figure 3 In the diagram, the various line types representing pipelines are as follows:

[0054] Pressure oil supply pipeline

[0055] Control piping

[0056] oil return line

[0057] Figure 4 This is a flowchart of a fault diagnosis method for the pilot valve-main and auxiliary follower valve of a speed governor hydraulic follower system according to the present invention. Detailed Implementation

[0058] like Figure 1 As shown, the hydraulic servo system of the speed controller includes a pilot valve-main distribution valve fault diagnosis system, comprising: a human-machine interface module 12, a controller 11, a stepper motor 3, a pilot valve 2, a main distribution valve 1, a relay 7, a displacement sensor, a speed measuring device and a power transmitter 16, and a communication medium.

[0059] Controller 11 is connected to stepper motor 3, stepper motor 3 is connected to pilot valve 2, pilot valve 2 is connected to main pressure regulating valve 1, and main pressure regulating valve 1 is connected to relay 7;

[0060] The pilot valve 2 is equipped with a first displacement sensor 5, which is used to measure the position M of the pilot valve core. 引 ;

[0061] The main pressure regulating valve 1 is equipped with a second displacement sensor 4, which is used to measure the position M of the valve core of the main pressure regulating valve. 主 ;

[0062] The relay 7 is equipped with a third displacement sensor 17, which is used to measure the guide vane position Y;

[0063] The first displacement sensor 5, the second displacement sensor 4, and the third displacement sensor 17 are all connected to the controller 11.

[0064] The relay 7 is connected to the hydro-generator set 13. The hydro-generator set 13 is equipped with a speed measuring device and a power transmitter 16, which are connected to the controller 11.

[0065] The speed measuring device and power transmitter 16 includes a power transmitter module and a speed signal device. The power transmitter module (NSD-PTM-V1.2) measures the power signal of single-phase or three-phase AC voltage and current signals. Through the host computer interface, the measured power signal can be converted into standard RS232, RS485, and Ethernet TCP / IP / IP / IP communication protocols; or output as a 4-20mA and 0-10V analog signal. The speed signal device RES3000 uses a high-performance industrial-grade CPU as the core control unit to achieve intelligent control of the turbine unit's speed and frequency.

[0066] The hydro-generator unit 13 is connected to the power grid 14, the power grid 14 is connected to the PT residual voltage frequency measuring device 15, and the PT residual voltage frequency measuring device 15 is connected to the controller 11.

[0067] The human-machine interaction module 12 is generally a touch screen, which realizes human-machine interaction functions. Users can use the human-machine interaction module 12 to compare the standard characteristic value Δ of the position deviation between the pilot valve and the main valve core in the fault judgment of the hydraulic follow-up system of the speed controller, and the standard characteristic value V of the position movement speed comparison between the main valve core and the pilot valve core. 标 The controller 11 receives parameters such as the condition holding time standard characteristic value T, as well as speed controller control commands; the controller 11 can display the position, frequency and other status information of the controlled object in real time through the human-machine interaction device 1 to inform the user.

[0068] The controlled objects include stepper motor 3, pilot valve 2, main pressure regulating valve 1, and hydro-generator set 13, which are directly or indirectly controlled. The mechanical structure diagram of the controlled objects is shown below. Figure 3 As shown, Figure 3 The serial number, name, code, and quantity of each component are shown in Table 1:

[0069] Table 1. Component serial number, name, code, and quantity

[0070] Serial Number name code name quantity Remark 1 Main pressure regulating valve 200DR 1 DN250 2 pilot valve 201DR 1 DN250 3 Stepper motor 102EB 1 4 Main pressure valve position sensor 111MN 1 5 pilot valve position sensor 112MM 1 6 Guide vane position sensor 101MM 1 7 relay JLQ 2 8 Relay ring JLH 1 9 Pressure oil tank YYG 1 10 Return to fuel tank HYX 1

[0071] The controller 11 collects the status signals of the controlled object through sensors, and processes various input signals in real time according to the control parameters and commands issued by the user through the human-machine interface module 12, and outputs control signals to the controlled object. The controller 11 can be a PLC, PCC, ARM, etc., from various brands. The control method adopts the classic closed-loop control theory. A schematic diagram of the closed-loop control structure of the electrical control system is shown below. Figure 2 As shown.

[0072] like Figure 2 As shown, the control objective of the guide vane opening control loop is that the guide vane opening feedback Y follows the guide vane opening given Y. 给定 It is achieved through an electrical negative feedback closed loop; the control objective of the main control loop is the position M of the main control valve core. 主 Following the primary and secondary given M 给定 It is controlled by the position M of the main valve core. 主 Follow the position M of the pilot valve spool 引 The mechanical negative feedback closed loop, pilot valve spool position M 引 Following the primary and secondary given M 给定 This is achieved through an electrical negative feedback closed loop. Specifically, M is given based on the position of the main valve core. 给定 Feedback M of pilot valve spool position 引 The difference in value controls the displacement of stepper motor 3, thereby controlling the position M of the pilot valve core. 引 Main valve core position M 主 Follow the position M of the pilot valve spool 引 This is achieved through a mechanical negative feedback closed loop.

[0073] The mechanical negative feedback closed-loop structure in which the position of the main valve spool follows the position of the pilot valve spool is as follows: Figure 3 As shown. By Figure 3 It can be seen that the valve sleeve of the pilot valve 2 and the valve core of the main pressure valve 1 are mechanically rigidly connected. When the valve core of the pilot valve 2 moves downward, the P port and A port of the pilot valve 2 are connected, and the Y end of the main pressure valve 1 is supplied with pressure oil. The valve core of the main pressure valve 1 moves downward, causing the valve sleeve of the pilot valve 2 to move downward. When the valve core and valve sleeve of the pilot valve 2 move to the same displacement, the P port and A port of the pilot valve 2 are no longer connected. At this time, the mechanical following system enters a steady state.

[0074] When the valve core of pilot valve 2 moves upward, the T port and A port of pilot valve 2 are connected, and the Y end of the main pressure regulating valve 1 is connected to pressureless return oil. The valve core of the main pressure regulating valve 1 moves upward, causing the valve sleeve of pilot valve 2 to move upward. When the valve core and valve sleeve of pilot valve 2 move to the same displacement, the T port and A port of pilot valve 2 are no longer connected. At this time, the mechanical following system enters a steady state.

[0075] As can be seen from the above process, this mechanical structure realizes a mechanical negative feedback closed-loop structure in which the position of the main valve (valve core) follows the position of the pilot valve (valve core).

[0076] The controller 11 employs a fault diagnosis method for the pilot valve-main-equipment follower system of the governor hydraulic follower system to diagnose faults in this system. The criteria for determining pilot valve-main-equipment follower faults are as follows:

[0077] |M 引 -M 主 |>△ and V M <V 标 And keep it for a time greater than T.

[0078] Where: △ is the standard characteristic value of the positional deviation comparison between the pilot valve and the main valve core in the pilot valve-main valve follower fault criterion;

[0079] V 标 In the fault criterion of the pilot valve-main and auxiliary valve, the position movement speed of the main and auxiliary valve cores is compared with the standard characteristic value.

[0080] T represents the standard characteristic value of the condition holding time in the pilot valve-main-feeder follower fault criterion.

[0081] A sensor is an electronic component or collection thereof that measures the state information parameters of various controlled objects, such as displacement sensors, speed measuring devices, and power transmitters. Figure 1 and Figure 3 As shown, the 112mm pilot valve displacement (position) sensor measures the position M of the pilot valve spool. 引 The 111mm displacement (position) sensor for the main pressure regulating valve measures the position (M) of the valve core. 主 The pilot valve displacement (position) sensor and the main pressure regulating valve displacement (position) sensor are of the same model and have the same range.

[0082] The communication medium is hardwired, network cable, or other communication cables, and its function is to transmit information flow between the human-machine interaction module 12, controller 11, controlled object, and sensor.

[0083] Methods for diagnosing faults in the pilot valve of the governor hydraulic follower system, such as... Figure 4 As shown, it includes the following steps:

[0084] Step 1: Initialize the speed controller electronic control system, Δ, V 标 Assign initial values ​​to T;

[0085] The initial value of △ is determined as follows: When the governor guide vane opening is tested from 0 to 100% in a step test, i.e., the guide vane opening is given by Y. 给定 When it changes from 0 to 100%, throughout the entire process |M 引 -M 主 The maximum value of | is set to △1;

[0086] When the governor guide vane opening is tested from 100% to 0% in a step change, i.e., the guide vane opening is given by Y... 给定 When it changes from 100% to 0, throughout the entire process |M 引 -M 主 Set the maximum value of ︱ to △2; set the larger of △1 and △2 as the initial value of △.

[0087] V 标 Method for determining initial values:

[0088] When the speed governor performs a positive Δ magnitude step test on the main control position, i.e., when the main control position is given by M... 给定 When the value changes from 0 to Δ, during the entire process, |M 主 -M 主(上一周期) Let the maximum value of | / Δt be V. 标1 When the speed governor performs a negative Δ magnitude main control position step test, that is, when the main control position setpoint M... 给定 When the value changes from 0 to -Δ, during the entire process, |M 主 -M 主(上一周期) Let the maximum value of | / Δt be V. 标2 V 标1 and V 标2 The smaller value in is set as V. 标 The initial value is Δt, which is the self-loop execution cycle of the controller 11 program.

[0089] Method for determining the initial value of T:

[0090] T is a positive integer multiple of Δt, and is usually determined based on the actual situation. The larger T is, the longer the fault diagnosis time is, and the easier it is to miss a diagnosis, but the less likely it is to be misdiagnosed; the smaller T is, the shorter the fault diagnosis time is, and the less likely it is to miss a diagnosis, but the more likely it is to be misdiagnosed.

[0091] Step 2: The governor's electronic control system acquires the guide vane position given Y input from the guide vane opening control module of the governor's hydraulic servo system in real time. 给定 Guide vane position feedback Y, output main and auxiliary position given M 给定 Main valve core position (feedback) M 主 Pilot valve spool position M 引 Data such as...

[0092] Step 3: Determine |M 引 -M 主 | Is it greater than the threshold △? If yes, proceed to step ④; if no, proceed to step ②.

[0093] Step 4: Calculate the main valve core position movement speed V M =|M 主 -M 主(上一周期) | / △t;

[0094] Step 5: Determine if |M 引 -M 主 |>△ and V M <V 标 And maintain this for a time greater than T. If yes, proceed to step 6; otherwise, proceed to step 2.

[0095] Step 6: Troubleshooting. If there is a backup speed controller (standby unit) and it is fault-free, switch to the backup speed controller (standby unit) and proceed to Step 2. If the backup speed controller (standby unit) is faulty or there is no backup speed controller (standby unit), switch to the manual control mode of the speed controller and proceed to Step 7.

[0096] The standby unit specifically refers to the backup speed controller.

[0097] Speed ​​governor controllers typically have three control modes: automatic, electric manual (EMT), and mechanical manual (MA). In automatic control mode, the speed governor controller uses PID closed-loop control to control the turbine guide vane opening. In EMT control mode, the speed governor controller uses EMT open-loop control to control the turbine guide vane opening. In MAMA control mode, the speed governor controller uses MAMT open-loop control to control the turbine guide vane opening.

[0098] Switching to manual mode specifically refers to switching to the manual control mode of the speed controller.

[0099] Step 7: If the fault is manually reset and the system switches to automatic control mode, proceed to Step 2.

[0100] The automatic control mode status specifically refers to the automatic control mode status of the speed controller.

Claims

1. A governor hydraulic servo system pilot valve-main valve follow-up failure diagnosis method, characterized by Comprising the following steps: Step 1: governor electric control system initialization, Δ, V 标 and T are assigned initial values; △ is the guide valve-main matching follow-up fault criterion, the guide valve and the main matching pressure valve spool position deviation compared to standard characteristic value; V 标 For the lead valve-main follow-up fault criterion, the main valve spool position moving speed is compared with the standard characteristic value. T is the guide valve-main matching follow-up fault criterion, the condition holding time standard characteristic value; Step 2: The governor electric control system collects the guide vane position given Y 给定 , guide vane position feedback Y, output main distribution position given M 给定 , main distribution spool position M 主 , guide valve spool position M 引 data in real time Step 3: Determine whether |M 引 -M 主 Step 4: If |M| is greater than threshold Δ, go to Step 5; otherwise, go to Step 2. Step 4: Calculate the main valve spool position movement speed V M =︱M 主 -M 主（上一周期） ︱ / △t;△t is the program self-loop execution period of the controller (11); Step 5: judge whether |M 引 -M 主 and V M < V 标 , V M is the main valve core position moving speed; And holding time is greater than T; if yes, go to step ⑥; if not, go to step ②; Step ⑥: fault handling, if there is a backup governor controller and no fault, switch to the backup governor controller, enter step ②; if the backup governor controller has a fault or there is no backup governor controller, switch to the governor controller manual control mode state, enter step ⑦; Step ⑦: if the artificial reset fault and switch to the automatic control mode state, enter step ②.

2. The governor hydraulic servo system guide valve-main matching follow-up fault diagnosis method according to claim 1, characterized in that: Step 1: The governor electric control system is initialized, Δ, V 标 and T are assigned initial values, including: The initial value determination method of Δ: guide vane opening given Y 给定 When changing from 0 to 100%, the maximum value of the whole process is 引 -M 主 The maximum value of is set as Δ1; Guide vane opening given Y 给定 When it changes from 100% to 0, during the entire process |M 引 -M 主 Set the maximum value of | to △2; set the larger of △1 and △2 as the initial value of △; V 标 initial value determination method: Main matching position given M 给定 When changing from 0 to Δ, the maximum value of |M 主 -M 主（上一周期） | / Δt is set as V 标1 ; Main matching position given M 给定 When changing from 0 to -Δ, the maximum value of |M 主 -M 主（上一周期） | / Δt is set as V 标2 ; The smaller value of V 标1 and V 标2 is set as the initial value of V 标 ; The initial value determination method of T: T is a positive integer multiple of △t.

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