Automatic Intelligent Setting System and Method for Pilot Valve Electrical Neutral Position of Governor Hydraulic Follow-up System

Abstract

An automatic intelligent setting system and method for the electrical neutral position of the pilot valve in a governor's hydraulic servo system is disclosed. The system includes a human-machine interface device, 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 connects to the pilot valve. The pilot valve is connected to the main pressure regulating valve, which is in turn connected to the relay. The pilot valve is equipped with a pilot valve displacement sensor to measure the position of its valve core. The main pressure regulating valve is equipped with a main pressure regulating valve displacement sensor to measure the position of its valve core. The relay is equipped with a relay displacement sensor to measure the position of its guide vanes. All three sensors are connected to the controller. This invention is applicable to the automatic setting of the electrical neutral position of the pilot valve in a governor's hydraulic servo system during unit maintenance, aiming to solve adjustment quality problems such as frequent adjustments and inability to adjust the guide vane opening to the correct position caused by inaccurate electrical neutral position setting of the governor's pilot valve.

Description

Technical Field

[0001] This invention relates to the field of hydraulic servo systems for speed governors, and specifically to an automatic intelligent setting system and method for the electrical neutral position of the pilot valve in a hydraulic servo system for speed governors. Background Technology

[0002] The Chinese patents “A self-diagnostic, self-positioning, and adaptive method for mid-position in a governor hydraulic servo system” (ZL: 201810113905.8); “A method for automatic intelligent mid-position positioning of the main distribution electrical system of a governor” (ZL: 202010489958.7); and “A system and method for automatic intelligent mid-position setting of the governor hydraulic servo system” (ZL: 201910024102.X) series of technical solutions can realize the mid-position setting function of the proportional valve and the main distribution electrical system of the governor hydraulic servo system. This function is suitable for hydropower units that use proportional valves (or proportional valves + stepper motors and other redundant configurations) and main distribution and relay devices as the actuation structure. Hydropower units that use a stepper motor + pilot valve and main distribution / relay unit as the actuation structure have a different control structure than those that use a proportional valve (or a proportional valve + stepper motor, etc., with redundant configuration) and main distribution / relay unit as the actuation mechanism. The electrical neutral position setting of the pilot valve is usually based on the valve core position of the pilot valve in the manual state after the stepper motor is reset and the control system returns to balance. This setting is usually not very accurate.

[0003] Currently, there is no mature and accurate manual or automatic setting system for the electrical neutral position of the governor's pilot valve. Inaccurate electrical neutral position setting of the governor's pilot valve often leads to frequent adjustments of the governor's hydraulic servo system and problems such as the inability to adjust the guide vane opening to the correct position, resulting in adjustment quality issues. Summary of the Invention

[0004] This invention provides an automatic intelligent setting system and method for the electrical neutral position of the pilot valve in a governor hydraulic follow-up system. It is applicable to hydropower units using a stepper motor + pilot valve and main / relay actuators as the actuators. During unit maintenance, this method automatically sets the electrical neutral position of the pilot valve in the governor hydraulic follow-up system, aiming to solve adjustment quality problems such as frequent adjustments and inability to adjust the guide vane opening to the correct position caused by inaccurate electrical neutral position setting of the governor pilot valve.

[0005] The technical solution adopted in this invention is as follows:

[0006] The governor hydraulic follow-up system pilot valve electrical neutral position automatic intelligent setting system includes:

[0007] Human-computer interaction devices, controllers, stepper motors, pilot valves, main pressure regulating valves, and relays;

[0008] The controller is connected to a stepper motor, the stepper motor is connected to a pilot valve, the pilot valve is connected to a main pressure regulating valve, and the main pressure regulating valve is connected to a relay. The pilot valve is equipped with a pilot valve displacement sensor to measure the position of the pilot valve core.

[0009] The main pressure regulating valve 1 is equipped with a main pressure regulating valve displacement sensor to measure the position of the main pressure regulating valve core;

[0010] The relay is equipped with a relay displacement sensor to measure the position of the guide vanes;

[0011] The pilot valve displacement sensor, the main pressure regulating valve displacement sensor, and the relay displacement sensor are all connected to the controller.

[0012] The human-machine interface device inputs the parameters of the initial electrical neutral setting value of the guide valve of the speed governor hydraulic follow-up system, the standard value ε of the guide valve electrical neutral drift criterion, the standard value ε′ of the guide valve electrical neutral setting completion criterion, and the control command into the controller.

[0013] 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.

[0014] The automatic intelligent setting method for the electrical neutral position of the speed governor pilot valve includes the following steps:

[0015] Step 1: Initial electrical neutral position setting of the speed controller pilot valve:

[0016] In the manual mode of the reference machine, after stepper motor 3 is reset, the control system restores the valve core position of the pilot valve to the balanced state, initially setting it to the electrical neutral position of the pilot valve, and recording the electrical neutral position value Y of the pilot valve. 中 Proceed to step 2;

[0017] 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.

[0018] The stepper motor 3-way return to the intermediate balance position refers to the stepper motor automatically returning to the intermediate balance position when the speed controller is in manual mode, and the pilot valve core and the main valve core follow suit and return to the intermediate balance position.

[0019] Step 2: Set the neutral position of the main distribution equipment using existing technology and record the neutral position value Z. 中 Proceed to step 3;

[0020] The existing technology for setting the neutral position of the main distribution valve specifically refers to a series of automatic setting technologies for the neutral position of the main pressure distribution valve disclosed in the existing technologies "A method for self-diagnosis, self-positioning and adaptive setting of the neutral position in a hydraulic servo system for a speed governor" (authorization announcement number: CN108468615B); "An automatic intelligent setting method for the neutral position in a hydraulic servo system for a speed governor" (authorization announcement number: CN109695533B); and "An automatic intelligent positioning method for the neutral position of the main distribution valve of a speed governor" (authorization announcement number: CN111749840B).

[0021] Step 3: With the speed governor in automatic to manual mode, perform a step test on the directional guide vanes. After the system stabilizes following the test, record the main and auxiliary position feedback channel value and assign this value to the variable Z. 开 To improve diagnostic accuracy, multiple tests can be conducted under different or the same opening conditions. The main and auxiliary position feedback channel values ​​recorded from multiple tests are then assigned to the variable Z. 开 Proceed to step 4;

[0022] The step test of the guide vane in the opening direction refers to the step test of the guide vane opening in the direction of increasing guide vane opening. The test is conducted by changing the electric manual guide vane opening setting value to change the guide vane opening from the initial value to the electric manual guide vane opening setting value.

[0023] Multiple tests are conducted under different or the same opening conditions. Specifically, this means selecting different or the same initial guide vane opening values ​​while maintaining a consistent guide vane step amplitude, and performing multiple guide vane opening step tests in the opening direction. For example, in Example 1, the initial guide vane opening value was the same (70%), and the guide vane step amplitude was kept consistent, resulting in four guide vane opening step tests in the opening direction. In Example 2, different initial guide vane opening values ​​were selected, while the guide vane step amplitude remained consistent, resulting in three guide vane opening step tests in the opening direction.

[0024] Step 4: Perform a step test on the opening of the guide vane. After the system stabilizes following the test, record the value of the main guide vane position feedback channel and assign this value to the variable Z. 关 To improve diagnostic accuracy, the test conditions can be consistent with the step test conditions for the directional guide vane opening. Multiple tests can be conducted under different or the same opening conditions, and the average value of the main and auxiliary position feedback channel records from multiple tests can be taken and assigned to the variable Z. 关 Proceed to step 5;

[0025] The closing direction guide vane opening step test specifically refers to conducting a guide vane opening step test in the direction of decreasing guide vane opening. This involves changing the electric manual guide vane opening setpoint to change the guide vane opening from its initial value to the setpoint. Multiple tests are conducted under different or the same opening conditions. Specifically, this means selecting different or the same initial guide vane opening values ​​while maintaining a consistent guide vane step amplitude, and performing multiple closing direction guide vane opening step tests. For example, in Example 1, four closing direction guide vane opening step tests were conducted with the same initial guide vane opening value of 70% and a consistent guide vane step amplitude; in Example 2, three closing direction guide vane opening step tests were conducted with different initial guide vane opening values ​​and a consistent guide vane step amplitude.

[0026] Step 5: Perform electrical neutral position drift diagnosis on the governor pilot valve, based on the following criteria:

[0027] (Z 开 +Z 关 ) / 2 and Z 中 The absolute value of the difference is greater than the standard value ε of the pilot valve electrical neutral position drift criterion, ε>0, and ε is usually determined by combining the measurement accuracy of the main and auxiliary position sensors and the setting accuracy of the pilot valve electrical neutral position.

[0028] If |(Z) 开 +Z 关 ) / 2-Z 中 If |>ε, then the pilot valve's electrical neutral position drifts, and the pilot valve's electrical neutral position setpoint Y... 中 If the settings are incorrect, proceed to step 6 to perform electrical neutral position setting of the pilot valve;

[0029] If |(Z) 开 +Z 关 ) / 2-Z 中 If ||ε, then the pilot valve electrical neutral position setpoint Y at this time 中 With proper settings, the electrical neutral position diagnostics of the pilot valve are complete.

[0030] ε is usually determined by a combination of the measurement accuracy of the main and auxiliary position sensors and the electrical neutral setting accuracy of the pilot valve, as follows: if the measurement accuracy requirement of the main and auxiliary position sensors is higher and the electrical neutral setting accuracy requirement of the pilot valve is higher, then ε can be set smaller; conversely, if the measurement accuracy requirement of the main and auxiliary position sensors is lower and the electrical neutral setting accuracy requirement of the pilot valve is lower, then ε can be set larger.

[0031] Step 6: Perform electrical neutral position setting for the governor pilot valve:

[0032] If (Z) 开 +Z 关 ) / 2-Z 中 If the value is less than or equal to ε′, then the pilot valve electrical neutral setting value Y 中Increase the step size i by yourself, that is, Y 中 +i is reassigned to Y 中 Proceed to step 7;

[0033] If (Z) 开 +Z 关 ) / 2-Z 中 When the value is greater than ε′, the pilot valve electrical neutral setting value Y 中 Decrease the step size i by yourself, that is, Y 中 -i is reassigned to Y 中 Proceed to step 7;

[0034] If |(Z) 开 +Z 关 ) / 2-Z 中 If |≦ε′, then the pilot valve electrical neutral position setting value Y at this time 中 With proper settings, the pilot valve's electrical neutral position setting is complete.

[0035] The increment step size i is a positive integer, which is determined comprehensively based on the measurement accuracy of the main and auxiliary position sensors, the speed requirement of the pilot valve's electrical neutral position setting, and the accuracy requirement of the pilot valve's electrical neutral position setting.

[0036] If the main position sensor has a higher measurement accuracy requirement, the pilot valve's electrical neutral setting speed requirement is not high, and the pilot valve's electrical neutral setting accuracy requirement is higher, then the step size i can be set smaller; conversely, if the main position sensor has a lower measurement accuracy requirement, the pilot valve's electrical neutral setting speed requirement is higher, and the pilot valve's electrical neutral setting accuracy requirement is lower, then the step size i can be set larger.

[0037] 1 represents the highest unit precision of the pilot valve's electrical neutral setting value. Since the step size i is a positive integer and 1 is the smallest positive integer step size, 1 represents the highest unit precision of the pilot valve's electrical neutral setting value.

[0038] The larger the increment step size i is, the faster the tuning speed, but the tuning accuracy will decrease.

[0039] The smaller the increment step size i, the slower the tuning speed, but the higher the tuning accuracy.

[0040] Increase or decrease the pilot valve electrical neutral position setting value Y 中 The cycle or speed can be optimized using some optimization strategies to improve adjustment efficiency and accuracy.

[0041] The standard value ε′ for determining the completion of the pilot valve's electrical neutral setting is usually determined by combining the measurement accuracy of the main and auxiliary position sensors and the accuracy of the pilot valve's electrical neutral setting, and ε≧ε′>0.

[0042] Step 7: Perform a step test on the directional guide vanes. After the system stabilizes following the test, record the position feedback channel value of the main guide vane and assign this value to the variable Z. 开To improve tuning accuracy, multiple tests can be conducted under different or the same opening conditions. The main and auxiliary position feedback channel values ​​recorded from multiple tests are then assigned to the variable Z. 开 Proceed to step 8;

[0043] Step 8: Perform a step test on the opening of the guide vane. After the system stabilizes following the test, record the value of the main guide vane position feedback channel and assign this value to the variable Z. 关 To improve tuning accuracy, the test conditions can be consistent with the step test conditions for the directional guide vane opening. Multiple tests can be conducted under different or the same opening conditions, and the average value of the main and auxiliary position feedback channel records from multiple tests can be taken and assigned to the variable Z. 关 Return to step 6.

[0044] This invention discloses an automatic intelligent electrical neutral position setting system and method for a hydraulic servo system guide valve of a speed governor, with the following technical advantages:

[0045] 1) This invention can solve the adjustment quality problems of frequent adjustments of the hydraulic follow-up system of the governor caused by inaccurate electrical neutral setting of the governor pilot valve.

[0046] 2) This invention can realize the automatic electrical neutral setting function of the governor guide valve, which is used for automatic electrical neutral setting of the guide valve during the maintenance of hydro-generator sets, replacing the tedious, complex and inaccurate manual setting operation, and improving the quality and level of maintenance.

[0047] 3) The pilot valve electrical neutral setting method of the present invention is simple and efficient, the setting result is accurate and reliable, and the setting process is fast and stable. Attached Figure Description

[0048] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0049] Figure 1 This is a schematic diagram of the hydraulic servo system of the speed controller in this invention.

[0050] Figure 2 This is a schematic diagram of the closed-loop control structure of the electronic control system of the present invention.

[0051] Figure 3 It is a mechanical structure diagram of the controlled object;

[0052] Figure 3 In the diagram, the various line types representing pipelines are as follows:

[0053] Pressure oil supply pipeline

[0054] Control piping

[0055] --------------Return Oil Pipeline

[0056] Figure 4 This is a flowchart of an automatic intelligent setting method for the electrical neutral position of a speed controller pilot valve according to the present invention. Detailed Implementation

[0057] The speed controller hydraulic follow-up system includes: human-machine interface device 11, controller 12, controlled object, sensor, and communication medium.

[0058] 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 objects. The mechanical structure diagram of the controlled objects is shown below. Figure 3 As shown.

[0059] The sensor is an electronic component or a 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 4 As shown:

[0060] Pilot valve displacement sensor 5 measures the position of the pilot valve spool;

[0061] The main pressure regulating valve displacement sensor 4 measures the position of the main pressure regulating valve core.

[0062] The relay displacement sensor 15 is used to measure the guide vane position Y;

[0063] The communication medium includes hardwired cables, network cables, and other communication cables, and its function is to transmit information flow between the human-computer interaction device 11, the controller 12, the controlled object, and the sensor.

[0064] 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 17, and the PT residual voltage frequency measuring device 17 is connected to the controller 12.

[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 a 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 human-machine interface device 11 is generally a touch screen, which realizes human-machine interaction functions. Users can input parameters such as the initial setting value of the electrical neutral position of the pilot valve of the speed governor hydraulic follow-up system, the standard value ε of the electrical neutral position drift criterion of the pilot valve, and the standard value ε′ of the electrical neutral position setting completion criterion of the pilot valve, as well as control commands, into the controller 12 through the human-machine interface device 11. The controller 12 can display the position, frequency and other status information of the controlled object in real time and inform the user through the human-machine interface device 1.

[0067] The controller 12 collects 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 11, and outputs control signals to the controlled object. The controller 12 can be a PLC, PCC, ARM, etc., from various brands. The control method adopts 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.

[0068] like Figure 2 As shown, the guide vane opening control loop aims to ensure that the guide vane opening feedback follows the given guide vane opening, which is achieved through an electrical negative feedback closed loop. The main control loop aims to ensure that the main control position follows the given main control position, which is achieved through a mechanical negative feedback closed loop where the main control position follows the pilot valve position, and an electrical negative feedback closed loop where the pilot valve position follows the given main control position. In other words, the stepper motor 3 is displaced based on the difference between the given main control position and the pilot valve position feedback, thereby controlling the pilot valve position. This is achieved through a mechanical negative feedback closed loop where the main control position follows the pilot valve position. The mechanical negative feedback closed loop structure where the main control position follows the pilot valve position is as follows: 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] Depend on Figure 3It can be seen that the valve sleeve of the pilot valve and the valve core of the main distribution valve are mechanically rigidly connected. When the valve core of the pilot valve moves downward, the P and A ports of the pilot valve 201DR are connected, and the Y end of the main distribution valve is supplied with pressurized oil. The downward movement of the main distribution valve core causes the valve sleeve of the pilot valve to move downward. When the displacements of the valve core and the valve sleeve of the pilot valve are the same, the P and A ports of the pilot valve 201DR are no longer connected, and the mechanical following system enters a steady state. When the valve core of the pilot valve moves upward, the T and A ports of the pilot valve 201DR are connected, and the Y end of the main distribution valve is supplied with pressureless return oil. The upward movement of the main distribution valve core causes the valve sleeve of the pilot valve to move upward. When the displacements of the valve core and the valve sleeve of the pilot valve are the same, the T and A ports of the pilot valve 201DR are no longer connected, and the mechanical following system enters a steady state. From the above process, it can be seen that this mechanical structure realizes a mechanical negative feedback closed-loop structure in which the position of the main distribution valve (valve core) follows the position of the pilot valve (valve core).

[0072] Example 1:

[0073] The speed governor control mode of a certain unit at Xiangjiaba Hydropower Station was switched to online B-set controller, electric manual operation mode, with stepper motor + pilot valve and main distribution and relay as the actuator, guide vane opening to 70%, fast door closed to keep the unit casing dry, speed governor in no-load state, forced input of unit speed 50HZ signal, and manual setting test of the electric neutral position of the speed governor pilot valve.

[0074] The steps for the automatic intelligent setting method of the electrical neutral position of the speed governor pilot valve are as follows:

[0075] Step (1): Initial setting of the electrical neutral position of the speed controller pilot valve: In the manual state of the reference machine, after the stepper motor is reset and the control system returns to the balanced state, the valve core position of the pilot valve is initially set as the electrical neutral position of the pilot valve, and the electrical neutral position value Y of the pilot valve is recorded. 中 Proceed to step (2);

[0076] Step (2): Set the neutral position of the main distribution equipment using existing technology and record the neutral position value Z of the main distribution equipment. 中 Proceed to step (3);

[0077] Step (3): With the governor switched to manual mode, perform a step test on the directional guide vanes. After the system stabilizes following the test, record the value of the main and auxiliary position feedback channel and assign this value to the variable Z. 开 To improve diagnostic accuracy, four electric-manual step tests were conducted with the guide vane opening increasing from 70% to 75% under a 70% opening condition. The main and auxiliary position feedback channel values ​​were recorded for each of the four tests. 开1 Z 开2 Z 开3 Z 开4 The average value of the primary and secondary position feedback channel recorded in the four experiments was assigned to the variable Z. 开Z 开 =(Z 开1 +Z 开2 +Z 开3 +Z 开4 ) / 4, proceed to step (4);

[0078] Step (4): Perform a step test on the opening of the guide vane. After the system stabilizes after the test, record the value of the main guide vane position feedback channel at this time and assign this value to the variable Z. 关 To improve diagnostic accuracy, four electric-manual step tests were conducted with the guide vane opening increasing from 70% to 65% under a 70% opening condition. The starting point of the step test for the closing guide vane opening was consistent with that of the step test for the opening guide vane opening, and the step amplitude was kept consistent. The main and auxiliary position feedback channel values ​​were recorded for each of the four tests. 关1 Z 关2 Z 关3 Z 关4 The average value of the primary and secondary position feedback channel recorded in the four experiments was assigned to the variable Z. 关 Z 关 =(Z 关1 +Z 关2 +Z 关3 +Z 关4 ) / 4, proceed to step (5);

[0079] Step (5): Perform electrical neutral position drift diagnosis on the governor pilot valve, based on the following criteria: (Z 开 +Z 关 ) / 2 and Z 中 The absolute value of the difference is greater than the standard value ε of the pilot valve electrical neutral position drift criterion, ε>0, and ε is usually determined to be 2 based on the combined measurement accuracy of the main and auxiliary position sensors and the electrical neutral position setting accuracy of the pilot valve.

[0080] If |(Z) 开 +Z 关 ) / 2-Z 中 If |>ε, then the pilot valve's electrical neutral position drifts, and the pilot valve's electrical neutral position setpoint Y... 中 If the settings are incorrect, proceed to step (6) to perform electrical neutral position setting of the pilot valve; if |(Z 开 +Z 关 ) / 2-Z 中 If ||ε, then the pilot valve electrical neutral position setpoint Y at this time 中 With proper settings, the electrical neutral position diagnostics of the pilot valve are complete.

[0081] Step (6): Perform electrical neutral position setting of the speed controller pilot valve. If (Z 开 +Z 关 ) / 2-Z 中 If the value is less than or equal to ε′, then the pilot valve electrical neutral setting value Y中 Increase the step size i by yourself, that is, Y 中 +i is reassigned to Y 中 Proceed to step (7); if (Z 开 +Z 关 ) / 2-Z 中 When the value is greater than ε′, the pilot valve electrical neutral setting value Y 中 Decrease the step size i by yourself, that is, Y 中 -i is reassigned to Y 中 Proceed to step (7); if |(Z 开 +Z 关 ) / 2-Z 中 If |≦ε′, then the pilot valve electrical neutral position setting value Y at this time 中 With proper settings, the pilot valve's electrical neutral position setting is complete.

[0082] The incrementing step size i is a positive integer, determined to be 1 based on the measurement accuracy of the main and auxiliary position sensors, the accuracy requirements of the pilot valve's electrical neutral setting speed, and the magnitude of the pilot valve's electrical neutral setting accuracy (1 represents the highest unit accuracy of the pilot valve's electrical neutral setting value). The standard value ε′ for completing the pilot valve's electrical neutral setting is also determined to be 1 based on the measurement accuracy of the main and auxiliary position sensors and the magnitude of the pilot valve's electrical neutral setting accuracy, i.e., the highest unit accuracy, satisfying ε≧ε′>0.

[0083] Step (7): Perform a step test on the directional guide vane. After the system stabilizes following the test, record the value of the main and auxiliary position feedback channel at this time and assign this value to the variable Z. 开 To improve the setting accuracy, four electric and manual step tests were conducted with the guide vane opening increasing from 70% to 75% under the 70% opening condition. The main and auxiliary position feedback channel values ​​were recorded for each of the four tests. 开1 Z 开2 Z 开3 Z 开4 The average value of the primary and secondary position feedback channel recorded in the four experiments was assigned to the variable Z. 开 Z 开 =(Z 开1 +Z 开2 +Z 开3 +Z 开4 ) / 4, proceed to step (8);

[0084] Step (8): Perform a step test on the opening of the guide vane. After the system stabilizes after the test, record the value of the main guide vane position feedback channel at this time and assign this value to the variable Z. 关To improve diagnostic accuracy, four electric-manual step tests were conducted with the guide vane opening increasing from 70% to 65% under a 70% opening condition. The starting point and step amplitude of the closing guide vane step test were consistent with those of the opening guide vane step test. The main and auxiliary position feedback channel values ​​were recorded for each of the four tests. 关1 Z 关2 Z 关3 Z 关4 The average value of the primary and secondary position feedback channel recorded in the four experiments was assigned to the variable Z. 关 Z 关 =(Z 关1 +Z 关2 +Z 关3 +Z 关4 ) / 4, return to step (6);

[0085] Example 2:

[0086] The speed governor control mode of a certain unit at Xiangjiaba Hydropower Station was switched to online B-set controller, electric manual operation mode, with stepper motor + pilot valve and main distribution and relay as the actuator, guide vane opening to 70%, fast door closed to keep the unit casing dry, speed governor in no-load state, forced input of unit speed 50HZ signal, and manual setting test of the electric neutral position of the speed governor pilot valve.

[0087] The steps for the automatic intelligent setting method of the electrical neutral position of the speed governor pilot valve are as follows:

[0088] Step ①: Initial setting of the speed controller pilot valve's electrical neutral position: Referencing the pilot valve's spool position in manual mode, after the stepper motor returns to center and the control system returns to balanced state, initially set this as the pilot valve's electrical neutral position and record the pilot valve's electrical neutral position value Y. 中 Proceed to step ②;

[0089] Step 2: Set the neutral position of the main distribution equipment using existing technology and record the neutral position value Z. 中 Proceed to step ③;

[0090] Step 3: With the speed governor switched to manual mode, perform a step test on the directional guide vanes. After the system stabilizes following the test, record the value of the main and auxiliary position feedback channels and assign this value to the variable Z. 开 To improve diagnostic accuracy, three electric-manual step tests were conducted at guide vane opening rates of 60%, 70%, and 80%, with a change of 5% in the guide vane opening. The main and auxiliary position feedback channel values ​​were recorded for each of the three tests. 开1 Z 开2 Z 开3 The average value of the primary and secondary position feedback channel recorded in the three experiments was assigned to the variable Z. 开 Z 开 =(Z开1 +Z 开2 +Z 开3 ) / 3, proceed to step ④;

[0091] Step 4: Perform a step test on the opening of the guide vane. After the system stabilizes following the test, record the value of the main guide vane position feedback channel and assign this value to the variable Z. 关 To improve diagnostic accuracy, three electric-manual step tests were conducted at 60%, 70%, and 80% guide vane openings with a decrease of 5%. The starting point of the step test for closing the guide vane opening was consistent with that for opening the guide vane, and the step amplitude was kept consistent. The main and auxiliary position feedback channel values ​​recorded for the three tests were Z. 关1 Z 关2 Z 关3 The average value of the primary and secondary position feedback channel recorded in the three experiments was assigned to the variable Z. 关 Z 关 =(Z 关1 +Z 关2 +Z 关3 ) / 3, proceed to step ⑤;

[0092] Step 5: Perform electrical neutral position drift diagnosis on the governor pilot valve. The criterion is: (Z 开 +Z 关 ) / 2 and Z 中 The absolute value of the difference is greater than the standard value ε of the pilot valve electrical neutral position drift criterion. ε>0 and ε is usually determined to be 2 based on the measurement accuracy of the main and auxiliary position sensors and the setting accuracy of the pilot valve electrical neutral position, i.e., the highest unit accuracy.

[0093] If |(Z) 开 +Z 关 ) / 2-Z 中 If |>ε, then the pilot valve's electrical neutral position drifts, and the pilot valve's electrical neutral position setpoint Y... 中 If the settings are incorrect, proceed to step ⑥ to perform the electrical neutral position setting of the pilot valve; if |(Z 开 +Z 关 ) / 2-Z 中 If ||ε, then the pilot valve electrical neutral position setpoint Y at this time 中 With proper settings, the electrical neutral position diagnostics of the pilot valve are complete.

[0094] Step 6: Perform electrical neutral position setting of the speed controller pilot valve. If (Z 开 +Z 关 ) / 2-Z 中 If the value is less than or equal to ε′, then the pilot valve electrical neutral setting value Y 中 Increase the step size i by yourself, that is, Y 中 +i is reassigned to Y 中 Proceed to step (7); if (Z开 +Z 关 ) / 2-Z 中 When the value is greater than ε′, the pilot valve electrical neutral setting value Y 中 Decrease the step size i by yourself, that is, Y 中 -i is reassigned to Y 中 Proceed to step ⑦; if |(Z 开 +Z 关 ) / 2-Z 中 If |≦ε′, then the pilot valve electrical neutral position setting value Y at this time 中 With proper settings, the pilot valve's electrical neutral position setting is complete.

[0095] The increment step size i is a positive integer, and is determined to be 2 based on the measurement accuracy of the main and auxiliary position sensors, the speed accuracy requirements of the pilot valve's electrical neutral position setting, and the magnitude of the pilot valve's electrical neutral position setting accuracy (1 is the highest unit accuracy of the pilot valve's electrical neutral position setting value). The standard value ε′ for the pilot valve's electrical neutral position setting completion criterion is determined to be 2 based on the measurement accuracy of the main and auxiliary position sensors and the magnitude of the pilot valve's electrical neutral position setting accuracy, satisfying ε≧ε′>0.

[0096] Step 7: Perform a step test on the directional guide vanes. After the system stabilizes following the test, record the position feedback channel value of the main guide vane and assign this value to the variable Z. 开 To improve the setting accuracy, three electric-manual step tests were conducted at 60%, 70%, and 80% guide vane openings with a change of +5%. The main and auxiliary position feedback channel values ​​were recorded for each of the three tests. 开1 Z 开2 Z 开3 The average value of the primary and secondary position feedback channel recorded in the three experiments was assigned to the variable Z. 开 Z 开 =(Z 开1 +Z 开2 +Z 开3 ) / 3, proceed to step ⑧;

[0097] Step 8: Perform a step test on the opening of the guide vane. After the system stabilizes following the test, record the value of the main guide vane position feedback channel and assign this value to the variable Z. 关 To improve diagnostic accuracy, three electric-manual step tests were conducted at 60%, 70%, and 80% guide vane openings, with the guide vane opening reduced by 5%. The starting point and step amplitude of the closing guide vane step test were consistent with those of the opening guide vane step test. The main and auxiliary position feedback channel values ​​were recorded for the three tests. 关1 Z 关2 Z 关3 The average value of the primary and secondary position feedback channel recorded in the three experiments was assigned to the variable Z. 关 Z 关=(Z 关1 +Z 关2 +Z 关3 ) / 3, return to step ⑥.

Claims

1. A method for automatically setting the electrical neutral position of a governor pilot valve, characterized in that The method comprises the following steps: Step 1: After the stepper motor (3) is homed, the control system restores the position of the spool of the pilot valve in the balanced state, and initially sets it to the electrical center of the pilot valve, and records the value Y of the electrical center of the pilot valve 中 , and enters Step 2; Step 2: Set the main power distribution center to the neutral position and record the main power distribution center neutral value Z 中 Go to Step 3. Step 3: The governor automatically cuts off the power and enters the manual state, and performs the opening direction guide vane step test. The main matching position feedback channel value recorded in multiple tests is taken and the value is assigned to the variable Z 开 , and step 4 is entered; Step 4: Do the guide vane opening step test in the closing direction, take the average value of the main matching position feedback channel value recorded in multiple tests, and assign the value to the variable Z 关 Enter Step 5; Step 5: Perform a governor guide valve electrical neutral drift diagnosis, with the criterion being: (Z) 开 +Z 关 ) / 2 and Z 中 The absolute value of the difference is greater than the standard value ε of the pilot valve electrical neutral position drift criterion, where ε>0; If |(Z 开 + Z 关 ) / 2 - Z 中 | > ε, then the pilot valve electrical center drifts, the pilot valve electrical center set value Y 中 is set incorrectly, go to step 6, and the pilot valve electrical center is adjusted. If |(Z 开 +Z 关 ) / 2-Z 中 |≦ε, then the electric neutral setting value Y 中 of the pilot valve is set reasonably, and the pilot valve electric neutral diagnosis is ended. Step 6: Perform governor guide valve electrical neutral setting: if (Z 开 + Z 关 ) / 2 - Z 中 < - ε', then the electrically neutral position setting value Y 中 of the pilot valve is increased by a step i, i.e. Y 中 is re-assigned the value Y 中 + i and step 7 is entered. ε' represents the guide valve electrical neutral setting completion criterion standard value; if (Z 开 + Z 关 ) / 2 - Z 中 > ε' then the electrically set value Y 中 of the pilot valve is reduced by a step i, i.e. Y 中 is re-assigned the value Y 中 - i and step 7 is entered. If |(Z 开 +Z 关 ) / 2-Z 中 |≦ε', then the electrically neutral setting value Y 中 of the pilot valve is set properly, and the setting of the electrically neutral of the pilot valve is completed. Step 7: Do the opening direction guide vane step test, take the main matching position feedback channel value recorded in multiple test records, and assign the value to variable Z 开 , enter step 8; Step 8: Do the closing direction guide vane opening step test, take the average value of the main matching position feedback channel value recorded in multiple tests, and assign the value to the variable Z 关 , return to step 6.

2. The governor guide valve electrical neutral automatic intelligent setting method according to claim 1, characterized in that: 1 is the highest unit precision of the guide valve electrical neutral setting value; The larger the self-increment step i is, the faster the setting speed is but the setting precision will decrease; The smaller the self-increment step i is, the slower the setting speed is but the setting precision will increase.

3. A setting system for performing the electric mid-position automatic intelligent setting method of the governor pilot valve according to claim 1, characterized in that, The system comprises: A human-computer interaction device (11), a controller (12), a stepping motor (3), a guide valve (2), a main pressure distribution valve (1), and a servomotor (7); The controller (12) is connected to the stepping motor (3), the stepping motor (3) is connected to the guide valve (2), the guide valve (2) is connected to the main pressure distribution valve (1), and the main pressure distribution valve (1) is connected to the servomotor (7); The guide valve (2) is provided with a guide valve displacement sensor (5) for measuring the position of the guide valve spool; The main pressure distribution valve (1) is provided with a main pressure distribution valve displacement sensor (4) for measuring the position of the main pressure distribution valve spool; The servomotor (7) is provided with a servomotor displacement sensor (15) for measuring the position of the guide vane; The guide valve displacement sensor (5), the main pressure distribution valve displacement sensor (4), and the servomotor displacement sensor (15) are all connected to the controller (12).

4. The tuning system of claim 3, wherein: The human-computer interaction device (11) inputs the governor hydraulic servo system guide valve electrical neutral preliminary setting value, the guide valve electrical neutral drift criterion standard value ε, the guide valve electrical neutral setting completion criterion standard value ε', and the control command into the controller (12).

5. The tuning system of claim 3, wherein: The servomotor (7) is connected to a hydroelectric generator set (13), the hydroelectric generator set (13) is provided with a speed measuring device and a power transmitter (16), and the speed measuring device and the power transmitter (16) are connected to the controller (12).

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