Method for checking valve cold protection of extra-high voltage converter station and integrated checking device

Abstract

This invention provides a verification method and integrated verification device for valve cooling protection in ultra-high voltage converter stations, belonging to the field of valve cooling protection operation and maintenance technology. The verification method includes: acquiring the selected target test item and its protection setting value; performing setting value verification on the target test item and its corresponding protection setting value; after the setting value verification is passed, constructing a test interval in the safe direction with the set percentage of the protection setting value as the offset amplitude; performing multiple setting value verifications at multiple points within the test interval to obtain the protection critical value of the target test item; evaluating the accuracy of the valve cooling system for the target test item based on the protection critical value; and superimposing an interference signal on the analog quantity based on the protection critical value to evaluate the anti-interference performance of the valve cooling system. This invention automatically simulates various sensor signals and automatically monitors and determines the protection action of the valve cooling system through standardized analog signals, breaking through the dependence of existing technologies on manual experience.

Description

Technical Field

[0001] This invention belongs to the field of valve cooling protection operation and maintenance technology, specifically involving a verification method and integrated verification device for valve cooling protection in ultra-high voltage converter stations. Background Technology

[0002] As a crucial hub for AC / DC power conversion, converter stations generate significant heat during the operation of their core equipment, the converter valves, which must be cooled by a valve cooling system. To ensure system safety, the valve cooling system is equipped with robust protection logic based on sensors for temperature, pressure, flow, and liquid level. The accuracy of its operation and the matching degree of its setpoints must be guaranteed through regular calibration. However, the development of dedicated equipment for valve cooling protection calibration is severely lagging behind, becoming a prominent weakness in intelligent operation and maintenance systems.

[0003] Currently, the industry commonly uses the manual potentiometer signal simulation verification method and the protection setting modification verification method. The typical process is that maintenance personnel manually adjust the potentiometer output analog signal to replace the real sensor signal, or directly modify the internal setting of the protection device, and manually observe and judge whether the protection logic is triggered normally.

[0004] Therefore, there is an urgent need for a method that can automatically simulate sensor signals and perform intelligent verification of valve cooling systems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a verification method and integrated verification device for valve cooling protection in ultra-high voltage converter stations.

[0006] A verification method for valve cooling protection in an ultra-high voltage converter station includes: acquiring the selected target test item and its protection setting value; verifying the setting value for the target test item and its corresponding protection setting value; after the setting value verification is passed, constructing a test interval with the set percentage of the protection setting value as the offset amplitude, moving towards the safe direction where the valve cooling system does not operate; performing multiple setting value verifications at multiple points within the test interval to obtain the protection critical value of the target test item; evaluating the accuracy of the valve cooling system for the target test item based on the protection critical value; and superimposing an interference signal into the analog quantity based on the protection critical value to evaluate the anti-interference performance of the valve cooling system.

[0007] Furthermore, the method for setting value verification includes: converting the digital set value into the corresponding analog target value, outputting the analog target value to the sensor signal input port corresponding to the target test item in the valve cooling system, and monitoring whether the valve cooling system performs protection actions through the trip output port of the valve cooling system.

[0008] Furthermore, the method for performing multiple fixed-value verifications at multiple points within the test interval includes: uniformly selecting n test points for each parameter within the test interval; selecting n test points for single-parameter test items and 2n test points for two-parameter test items; repeatedly performing fixed-value verification m times for each test point; and statistically analyzing the results of each fixed-value verification to obtain the action probability of each test point.

[0009] Furthermore, the method for selecting 2n test points for dual-parameter test items includes: fixing one parameter as its protection setting value, and selecting n test points within the test interval for the other parameter; fixing the other parameter as its protection setting value, and selecting n test points within the test interval for the other parameter.

[0010] Furthermore, the method for obtaining the protection critical value of the target test item includes: selecting the test point with an action probability of 100% and the largest deviation from the protection setting as the protection critical point, and the value corresponding to the protection critical point is the protection critical value.

[0011] Furthermore, the method for evaluating the accuracy of the valve cooling system for the target test item based on the protection critical value includes: obtaining the deviation rate of the protection critical value relative to the protection set value; for two-parameter test items, calculating the deviation rate of each parameter separately, and taking the maximum value as the deviation rate of the test item; if the deviation rate is less than the set value, the accuracy evaluation is considered to be passed.

[0012] Furthermore, the method for evaluating the anti-interference performance of the valve cooling system by superimposing interference signals into the analog quantity includes: converting the protection threshold value into the corresponding analog quantity target value, superimposing interference signal components with gradually increasing amplitudes onto the analog quantity target value, monitoring whether the valve cooling system performs protection actions after each amplitude change; recording the maximum interference signal amplitude when the valve cooling system can still correctly perform protection actions during the last time the interference signal is superimposed, comparing this amplitude with a preset reference amplitude, and determining whether the anti-interference performance of the valve cooling system is qualified.

[0013] Furthermore, the target test items include over-temperature protection test, under-liquid level protection test, under-flow rate and under-inlet valve pressure protection test, under-flow rate and under-inlet valve pressure protection test, and under-inlet valve pressure and under-outlet valve pressure protection test.

[0014] Furthermore, the interference signal components include at least one of power frequency interference, aging drift interference, and signal jitter interference.

[0015] An integrated verification device for valve cooling protection in an ultra-high voltage converter station includes a portable carrying case and a main control unit and an analog output unit housed within the carrying case. An operation panel is located on the top surface of the carrying case, and the operation panel includes a human-machine interface unit and an interface unit for connecting to the sensor signal input interface of the valve cooling system. The analog output unit is electrically connected between the main control unit and the interface unit. The analog output unit is used to output a standard industrial current signal under the control of the main control unit. The main control unit is used to execute the verification method described above.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention automatically simulates various sensor signals using standardized analog signals, automatically monitors and determines the protection actions of the valve cooling system, breaking through the reliance on manual experience in existing technologies and upgrading the verification process from "manual verification" to "autonomous verification." This invention uses a main control unit to control the analog output unit to output a stable standard signal. Compared to existing technologies that manually adjust potentiometers, this eliminates the impact of instantaneous inrush currents and voltage spikes generated by manual adjustment on the precision acquisition board of the valve cooling system. This invention employs multi-channel synchronous analog output, which can simultaneously simulate multiple sensor signals such as temperature, pressure, flow rate, and liquid level, thereby enabling the verification of complex protection logic such as single-parameter and dual-parameter test items.

[0017] This invention employs a standardized linear conversion algorithm to convert protection setpoints into analog target values. By performing multiple verifications at multiple points within a test interval and statistically analyzing the probability of action at each test point, it accurately identifies the protection critical value. Compared to existing manual single-point adjustments, this significantly improves the accuracy of capturing critical action points and the repeatability of data, effectively avoiding the accumulation of verification errors caused by human error and equipment temperature drift. Based on the protection critical value, this invention superimposes three types of interference signals representing typical converter station operating conditions—power frequency interference, aging drift, and signal jitter—onto the analog quantity. This quantitatively evaluates the anti-interference capability of the valve cooling system under actual complex electromagnetic and aging environments, significantly improving the consistency between the verification results and actual field conditions.

[0018] This invention integrates main control, analog output, and human-machine interaction units into a portable carrying case. Standardized plug-in terminals reduce traditional wiring time from tens of minutes to less than 5 minutes. It also reserves two external sensor channels, enabling the engineering implementation of the aforementioned high-precision verification method. The device can achieve fully automated verification with a single connection at the converter station site, significantly reducing the field wiring error rate and operational threshold, and realizing the integration, portability, and automation of the verification device. Attached Figure Description

[0019] The present invention will now be described in further detail with reference to the accompanying drawings.

[0020] Figure 1 : Flowchart of Embodiment 1 of the present invention; Figure 2 : A schematic diagram of the structure of Embodiment 2 of the present invention; Figure 3 : A schematic diagram of the fixed value verification interface displayed by the human-computer interaction unit in Embodiment 2 of the present invention; Figure 4 : A schematic diagram of the temperature protection setpoint verification interface displayed by the human-computer interaction unit in Embodiment 2 of the present invention; Figure 5 : A schematic diagram of the pressure protection setting verification interface displayed by the human-machine interaction unit in Embodiment 2 of the present invention; Figure 6 : A schematic diagram of the liquid level protection setting value verification interface displayed by the human-computer interaction unit in Embodiment 2 of the present invention; Figure 7 : A schematic diagram of the flow and pressure protection setting verification interface displayed by the human-computer interaction unit in Embodiment 2 of the present invention; Figure 8 : A schematic diagram of the test window interface displayed by the human-computer interaction unit in Embodiment 2 of the present invention; Figure 9 : A schematic diagram of the verification record interface displayed by the human-computer interaction unit in Embodiment 2 of the present invention; Among them: 1-Portable carrying case, 2-Interface unit, 3-Human-computer interaction unit, 4-Main control unit. Detailed Implementation

[0021] To better understand the present invention, the content of the invention is further clearly illustrated below with reference to embodiments and accompanying drawings. However, the scope of protection of the present invention is not limited to the embodiments described below. Numerous specific details are set forth in the following description to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details.

[0022] Example 1: See Figure 1 The purpose of this embodiment is to provide a verification method for valve cooling protection in ultra-high voltage converter stations, including: S1. Obtain the selected target test item and its protection setting.

[0023] The test items include single-parameter test items such as overheat protection test and low liquid level protection test, as well as dual-parameter test items such as low flow rate and low inlet valve pressure protection test, low flow rate and high inlet valve pressure protection test, and low inlet valve pressure and low outlet valve pressure protection test.

[0024] The over-temperature protection test corresponds to the high temperature protection setting. When the temperature is greater than or equal to the high temperature protection setting, the valve cooling system should trip for protection.

[0025] The protection setting corresponding to the low liquid level protection test is the low liquid level protection setting. When the liquid level is less than or equal to the low liquid level protection setting, the valve cooling system should trip for protection.

[0026] The protection settings for the low flow rate and low inlet valve pressure protection test are the low flow rate protection setting and the low inlet valve pressure protection setting. When the flow rate is less than or equal to the low flow rate protection setting and the inlet valve pressure is less than or equal to the low inlet valve pressure protection setting, the valve cooling system should trip.

[0027] The protection settings for the low flow rate and high inlet valve pressure protection test are the low flow rate protection setting and the high inlet valve pressure protection setting. When the flow rate is less than or equal to the low flow rate protection setting and the inlet valve pressure is greater than or equal to the high inlet valve pressure protection setting, the valve cooling system should trip.

[0028] The protection settings corresponding to the inlet valve pressure too low and outlet valve pressure too low protection test are the inlet valve pressure low protection setting and the outlet valve pressure low protection setting. When the inlet valve pressure is less than or equal to the inlet valve pressure low protection setting and the outlet valve pressure is less than or equal to the outlet valve pressure low protection setting, the valve cooling system should trip for protection.

[0029] S2. Verify the setting values ​​for the target test items and their corresponding protection settings.

[0030] The method for setting value verification includes: converting digital setting values ​​(such as protection setting values) into corresponding analog target values; outputting the analog target values ​​to the sensor signal input ports corresponding to the target test items in the valve cooling system; and monitoring whether the valve cooling system executes a protection action through the trip output port of the valve cooling system. Combined with the corresponding delay time of the valve cooling system, if a protection action is detected after the delay, the setting value verification is considered successful; otherwise, it is considered unsuccessful.

[0031] Taking the low liquid level protection test as an example, during the setting value verification, the low liquid level protection setting value is converted into an analog quantity, and the corresponding analog target value is output to the input port of the liquid level sensor signal in the valve cooling system, and the protection action of the valve cooling system is monitored.

[0032] Taking the low flow rate and high inlet valve pressure protection test as an example, during the setpoint verification, the low flow rate protection setpoint is converted into an analog signal and output to the input port of the flow sensor signal in the valve cooling system; the high inlet valve pressure protection setpoint is converted into an analog signal and simultaneously output to the input port of the inlet valve pressure sensor signal in the valve cooling system. Finally, it is monitored whether the valve cooling system executes the protection action.

[0033] The digital quantity is converted into an analog quantity according to the following formula: , The output is the analog value. It is a numerical value. , These are the upper and lower limits of the analog output range, respectively. , These represent the upper and lower limits of the corresponding numerical values.

[0034] This step verifies whether the current protection settings are correct. If the settings verification passes, proceed to the next step; otherwise, record the exception and terminate the subsequent testing of the target test item.

[0035] S3. After the setting value verification is passed, the test range is constructed in the safe direction with the set percentage of the protection setting value as the offset range.

[0036] The test interval (d = 5-20) is constructed using the protection setpoint and its offset towards the safety direction by d%. For high protection setpoints such as high temperature and high inlet valve pressure, the direction in which the value decreases is the safety direction; for low protection setpoints such as low liquid level and low flow rate, the direction in which the value increases is the safety direction.

[0037] S4. Perform multiple point-based value verifications within the test interval to obtain the protection threshold value of the target test item.

[0038] The method for performing multiple-point, multiple-time setting value verification within a test interval includes the following steps: Within the test interval, for each parameter, uniformly select n test points (including the two boundary points of the test interval, where n is 5–10) in the direction away from the protection setting value. For single-parameter test items, n test points are ultimately selected. For dual-parameter test items, fix one parameter as its protection setting value, and select n test points within the test interval for the other parameter; after swapping the roles of the two parameters, select another n test points, ultimately selecting 2n test points. For each test point, repeat the setting value verification m times (where m is 5–10). Statistically analyze the results of each setting value verification to obtain the probability of action (the probability of passing the setting value verification) for each test point.

[0039] The method for obtaining the protection critical value of the target test item includes: selecting the test point with an action probability of 100% and the largest deviation from the protection set value as the protection critical point, and the value corresponding to the protection critical point is the protection critical value.

[0040] S5. Evaluate the accuracy of the valve cooling system for the target test items based on the protection critical value.

[0041] To obtain the deviation rate of the protection critical value relative to the protection setpoint, for two-parameter test items, calculate the deviation rate for each parameter separately, and use the maximum value as the deviation rate for that test item. The deviation rate is the ratio of the absolute value of the difference between the protection critical value and the protection setpoint to the protection setpoint. If the deviation rate is less than the setpoint, the accuracy assessment is passed. The smaller the deviation rate, the higher the degree of conformity between the actual operating point of the valve cooling system and the protection setpoint (setpoint), and the more accurate the setpoint configuration. The larger the deviation rate, the more the actual operating point of the protection device deviates from the setpoint, indicating a potential risk of malfunction due to sampling errors or other factors.

[0042] S6. Based on the protection critical value, superimpose the interference signal into the analog quantity to evaluate the anti-interference performance of the valve cooling system.

[0043] The protection threshold is converted into a corresponding analog target value. An interference signal component with gradually increasing amplitude is superimposed on this analog target value. After each amplitude change, the valve cooling system is monitored to see if it executes the protection action. The maximum interference signal amplitude is recorded when the valve cooling system can still correctly execute the protection action during the superimposed interference signal process. This amplitude is compared with a preset reference amplitude to determine whether the valve cooling system's anti-interference performance is qualified. For example, the reference amplitude for power frequency interference is 1%–2% of the sensor range, the reference amplitude for aging drift is 1% of the sensor range, and the reference amplitude for signal jitter is 0.5% of the sensor range.

[0044] Interference signal components include at least one of power frequency interference, aging drift interference, and signal jitter interference. Power frequency interference is a sinusoidal (50Hz) power frequency component superimposed on the analog quantity, which can simulate electromagnetic interference caused by the power frequency within the converter station; aging drift interference is a linearly time-varying offset component superimposed on the analog quantity, which can simulate the aging drift of the sensor; signal jitter interference is a low-frequency random jitter superimposed on the analog quantity, which can simulate the unstable output of the sensor caused by poor contact, vibration, etc.

[0045] Example 2: See Figures 2-9 The purpose of this embodiment is to provide an integrated verification device for valve cooling protection in an ultra-high voltage converter station, including a portable carrying case 1 and a main control unit 4 and an analog output unit disposed within the portable carrying case 1. An operation panel is provided on the top surface of the portable carrying case 1, and the operation panel is equipped with a human-machine interface unit 3 and an interface unit 2 for connecting to the sensor signal input interface of the valve cooling system.

[0046] Interface unit 2 is electrically connected to the analog output unit and features a terminal block with 12 standardized plug-in terminals, compatible with temperature, pressure, flow, and level signals. The terminals employ a cylindrical metal pin contact design with a contact resistance of less than 5mΩ, ensuring stable transmission of analog signals. Interface unit 2 has two reserved channels for external sensors, allowing direct connection to actual field sensors for signal comparison. Interface unit 2 enables rapid docking between the calibration device and the valve cooling system.

[0047] The human-machine interface unit 3 is electrically connected to the main control unit 4 and uses a touchscreen, enabling the visual input of various sensor ranges and protection settings. The main control unit 4 also transmits real-time data such as analog output values, valve cooling system feedback signals, and calibration progress back to the human-machine interface unit 3 for visual display. Figures 3-9 This is a schematic diagram of the display interface of the human-computer interaction unit 3.

[0048] The analog output unit is used to output 4-20mA standard industrial current signals under the control of the main control unit 4. It also supports multi-channel synchronous output and can simultaneously simulate multiple physical quantity signals such as temperature, pressure, flow rate, and liquid level.

[0049] The main control unit 4 is used to execute the verification method provided in Example 1.

[0050] Specifically, the main control unit 4 includes a setting value verification module, a test interval construction module, a protection critical value acquisition module, an accuracy evaluation module, and an anti-interference evaluation module. The setting value verification module is used to verify the setting value for the target test item and its corresponding protection setting value; in conjunction with Embodiment 1, the setting value verification module is used to execute step S2. The test interval construction module is used to construct a test interval in the safe direction with a set percentage d of the protection setting value as the offset amplitude; in conjunction with Embodiment 1, the test interval construction module is used to execute step S3. The protection critical value acquisition module is used to perform multiple setting value verifications at multiple points within the test interval to obtain the protection critical value of the target test item; in conjunction with Embodiment 1, the protection critical value acquisition module is used to execute step S4. The accuracy evaluation module is used to evaluate the accuracy of the valve cooling system for the target test item based on the protection critical value; in conjunction with Embodiment 1, the accuracy evaluation module is used to execute step S5. The anti-interference evaluation module is used to evaluate the anti-interference performance of the valve cooling system by superimposing an interference signal into the analog quantity based on the protection critical value; in conjunction with Embodiment 1, the anti-interference evaluation module is used to execute step S6.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention, as long as they do not depart from the spirit and scope of the technical solutions of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. A verification method for valve cooling protection in an ultra-high voltage converter station, characterized in that, include: Obtain the selected target test items and their protection settings; Verify the setting values ​​for the target test items and their corresponding protection settings; After the setting value verification is passed, the test range is constructed in the safe direction of the valve cooling system not operating, with the set percentage of the protection setting value as the offset range; Perform multiple point-based value verifications within the test interval to obtain the protection threshold value of the target test item; The accuracy of the valve cooling system for the target test items is evaluated based on the protection threshold. Based on the protection threshold, an interference signal is superimposed on the analog quantity to evaluate the anti-interference performance of the valve cooling system.

2. The verification method for valve cooling protection in an ultra-high voltage converter station according to claim 1, characterized in that, The method for setting value verification includes: converting the digital set value into the corresponding analog target value, outputting the analog target value to the sensor signal input port corresponding to the target test item in the valve cooling system, and monitoring whether the valve cooling system performs protection actions through the trip output port of the valve cooling system.

3. The verification method for valve cooling protection in UHV converter stations according to claim 1, characterized in that, The method for performing multiple fixed-value verifications at multiple points within the test interval includes: uniformly selecting n test points for each parameter within the test interval; selecting n test points for single-parameter test items and 2n test points for two-parameter test items; repeatedly performing fixed-value verification m times for each test point; and statistically analyzing the results of each fixed-value verification to obtain the action probability for each test point.

4. The verification method for valve cooling protection in UHV converter stations according to claim 3, characterized in that, Methods for selecting 2n test points for dual-parameter test items include: fixing one parameter as its protection setting value, and selecting n test points within the test interval for the other parameter; or fixing the other parameter as its protection setting value, and selecting n test points within the test interval for the other parameter.

5. The verification method for valve cooling protection in an ultra-high voltage converter station according to claim 1, characterized in that, The method for obtaining the protection critical value of the target test item includes: selecting the test point with an action probability of 100% and the largest distance from the protection setting as the protection critical point, and the value corresponding to the protection critical point is the protection critical value.

6. The verification method for valve cooling protection in an ultra-high voltage converter station according to claim 1, characterized in that, The method for evaluating the accuracy of a valve cooling system for a target test item based on the protection critical value includes: obtaining the deviation rate of the protection critical value relative to the protection set value; for two-parameter test items, calculating the deviation rate of each parameter separately, and taking the maximum value as the deviation rate of the test item; if the deviation rate is less than the set value, the accuracy evaluation is considered to be passed.

7. The verification method for valve cooling protection in an ultra-high voltage converter station according to claim 1, characterized in that, The method for evaluating the anti-interference performance of a valve cooling system by superimposing interference signals onto an analog quantity includes: converting the protection threshold value into a corresponding analog target value; superimposing interference signal components with gradually increasing amplitudes onto the analog target value; monitoring whether the valve cooling system performs a protection action after each amplitude change; recording the maximum interference signal amplitude when the valve cooling system can still correctly perform a protection action during the last time the interference signal is superimposed; comparing this amplitude with a preset reference amplitude to determine whether the anti-interference performance of the valve cooling system is qualified.

8. The verification method for valve cooling protection in an ultra-high voltage converter station according to claim 1, characterized in that, The target test items include over-temperature protection test, under-liquid level protection test, under-flow rate and under-inlet valve pressure protection test, under-flow rate and under-inlet valve pressure protection test, and under-inlet valve pressure and under-outlet valve pressure protection test.

9. The verification method for valve cooling protection in an ultra-high voltage converter station according to claim 7, characterized in that, The interference signal components include at least one of power frequency interference, aging drift interference, and signal jitter interference.

10. An integrated verification device for valve cold protection in an ultra-high voltage converter station, characterized in that, It includes a portable carrying case and a main control unit and an analog output unit disposed within the portable carrying case; the top surface of the portable carrying case is provided with an operation panel, and the operation panel is provided with a human-machine interaction unit and an interface unit for connecting to the sensor signal input interface of the valve cooling system; The analog output unit is electrically connected between the main control unit and the interface unit; The analog output unit is used to output a standard industrial current signal under the control of the main control unit. The main control unit is used to execute the verification method as described in any one of claims 1-9.

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