Split type on-load tap-changer mechanical clamping stagnation fault detection method and system

Abstract

The invention relates to the technical field of high-voltage direct-current transmission, and discloses a split type on-load tap-changer mechanical clamping stagnation fault detection method and system, and the method comprises the steps: judging whether a switch switching module has transition resistance loss or not based on first current data; gear switching delay time and a gear shifting instruction response state in the gear switching process are collected; acquiring second current data of the converter transformer at a plurality of gear switching point monitoring positions, and judging whether the switch switching module has the condition that the mechanical frictional resistance exceeds the standard to cause the short-circuit current peak value to exceed the limit or not based on the second current data; acquiring third current data of the converter transformer in the operation module, and comparing and analyzing the third current data to obtain a fault mode classification result of the switch switching module; and performing cooperative processing on the fault mode classification result and the gear shifting instruction response state to obtain a target alarm signal. According to the invention, accurate identification and timely protection of mechanical clamping stagnation faults can be realized in a complex and changeable operation environment.

Description

Technical Field

[0001] The present invention relates to the technical field of high - voltage direct - current power transmission, and particularly to a method and system for detecting mechanical jamming faults of a split - type on - load tap - changer. Background Art

[0002] The on - load tap - changer of the converter transformer for UHV DC power transmission, as a key component for voltage regulation, maintains stable power transmission of the DC system at the rated voltage and low voltage by dynamically adjusting the tap position of the converter transformer. According to the structure, the on - load tap - changer can be divided into an integral on - load tap - changer and a split - type on - load tap - changer, both of which are composed of a switch selection part and a switch switching part.

[0003] The performance of the split - type on - load tap - changer is crucial for the stability and reliability of the system. However, in actual operation, the switch switching part is prone to mechanical jamming faults, resulting in tap - position switching failures and even serious consequences. There are some drawbacks in traditional fault - detection means: on the one hand, only when the fault range expands and causes the converter transformer protection to act can the fault circuit be cut off, which often causes great losses to the converter transformer; on the other hand, traditional fault - detection means are difficult to accurately identify different types of mechanical jamming faults, especially in the case of an inter - stage short - circuit formed by a transition resistance, resulting in the protection measures being difficult to respond precisely and affecting the system operation efficiency. Moreover, mechanical jamming faults are transient. Therefore, how to quickly and accurately detect mechanical jamming faults in a complex power environment has become an urgent problem to be solved. Summary of the Invention

[0004] In view of the above problems, the present invention provides a method and system for detecting mechanical jamming faults of a split - type on - load tap - changer.

[0005] In a first aspect, an embodiment of the present invention provides a method for detecting mechanical jamming faults of a split - type on - load tap - changer. The split - type on - load tap - changer is applied to a converter transformer. The split - type on - load tap - changer includes a switch switching module, a switch selection module, a flange, and an operation module. Among them, the flange is disposed between the switch switching module and the switch selection module, and the operation module is used to drive the switch switching module and the switch selection module to act to achieve tap - position switching; The method for detecting mechanical jamming faults of the split - type on - load tap - changer includes: During the operation of the converter transformer, obtaining first - current data of several circuits of the converter transformer, and judging whether there is a missing transition resistance in the switch switching module based on the first - current data; Receive the tap-changing command sent by the converter control system, control the converter transformer to perform the tap-changing process based on the tap-changing command, and collect the tap-changing delay time and the response status of the tap-changing command during the tap-changing process; Within the inter-stage short-circuit detection window corresponding to the tap-changing delay time, obtain the second current data at the monitoring positions of several tap-changing points of the converter transformer, and determine whether the switching module has an excessive short-circuit current peak caused by excessive mechanical friction resistance based on the second current data; During the tap-changing process of the converter transformer, obtain the third current data of the converter transformer at the operation module, and perform comparative analysis on the third current data to obtain the fault mode classification result of the switching module; Perform collaborative processing on the fault mode classification result and the response status of the tap-changing command to obtain a target alarm signal, where the target alarm signal includes the fault location information of the switching module.

[0006] Preferably, after performing collaborative processing on the fault mode classification result and the response status of the tap-changing command to obtain a target alarm signal, it further includes: Obtain the real-time operation status data of the split-type on-load tap-changer, and determine whether the split-type on-load tap-changer has a risk of jamming based on the real-time operation status data. If so, stop the split-type on-load tap-changer, where the real-time operation status data includes real-time temperature data and real-time vibration frequency; Obtain the contact wear degree data of the split-type on-load tap-changer, and determine whether the split-type on-load tap-changer has continuous mechanical jamming caused by contact wear based on the contact wear degree data. If so, take protective operations on the converter transformer.

[0007] Preferably, during the operation of the converter transformer, obtaining the first current data of several circuits of the converter transformer and determining whether the switching module has a missing transition resistance includes: During the operation of the converter transformer, obtain the first current signal of the converter transformer in the primary circuit and the second current signal of the converter transformer in the secondary circuit; Extract the spectral characteristics of the first current signal to obtain the high-frequency component of the first current signal; Judge whether the amplitude of the high-frequency component is greater than the first preset threshold and whether the second current signal is less than the second preset threshold. If so, determine that the switching module has a missing transition resistance.

[0008] Preferably, the collecting the tap-changing delay time and the response status of the tap-changing command during the tap-changing process includes: Record the start time and end time of the gear shifting process, and characterize the difference between the end time and the start time as the gear shifting delay time; After performing the gear shifting process, obtain the real-time mechanical operation state of the split on-load tap-changer, and characterize the real-time mechanical operation state as the response state of the tap-changing command.

[0009] Preferably, the obtaining the second current data at the monitoring positions of the converter transformer at several gear shifting points and determining whether there is an excessive short-circuit current peak caused by excessive mechanical friction resistance in the switch switching module based on the second current data includes: Obtain the third current signal at the monitoring position of the converter transformer at the first gear shifting point and the fourth current signal at the monitoring position of the converter transformer at the second gear shifting point; Determine whether both the third current signal and the fourth current signal are greater than the third preset threshold. If so, it is determined that there is an excessive short-circuit current peak caused by excessive mechanical friction resistance in the switch switching module.

[0010] Preferably, the operation module includes a motor and a transmission unit. The obtaining the third current data of the converter transformer in the operation module and performing comparative analysis on the third current data to obtain the fault mode classification result of the switch switching module includes: Obtain the fifth current signal and the sixth current signal at both ends of the motor of the converter transformer; Obtain the seventh current signal at the first detection point of the transmission unit of the converter transformer and the eighth current signal at the second detection point of the transmission unit of the converter transformer; Perform comparative analysis on the fifth current signal, the sixth current signal, the seventh current signal, and the eighth current signal based on the fourth preset threshold to obtain the first fault mode classification result of the switch switching module; Dynamically adjust the fourth preset threshold to obtain a dynamic current threshold, and optimize the first fault mode classification result based on the dynamic current threshold to obtain a second fault mode classification result; Characterize the second fault mode classification result as the fault mode classification result of the switch switching module.

[0011] Preferably, the collaborative processing of the fault mode classification result and the response state of the tap-changing command to obtain the target alarm signal includes: Generate an initial alarm signal based on the fault mode classification result; Determine whether the response state of the tap-changing command matches the preset mechanical operation state. If so, generate an intermediate alarm signal based on the initial alarm signal; Perform clustering analysis on the intermediate alarm signal to obtain the fault location information of the switch switching module; Optimize the intermediate alarm signal using a decision tree algorithm based on the fault location information to obtain the target alarm signal.

[0012] Preferably, the method for obtaining the real-time operating state data of the split type on-load tap-changer and determining whether there is a risk of jamming in the split type on-load tap-changer based on the real-time operating state data, and if so, stopping the operation of the split type on-load tap-changer, includes: Obtain the real-time temperature data and real-time vibration frequency of the split type on-load tap-changer; Judge whether the real-time temperature data exceeds a preset temperature threshold or the real-time vibration frequency is greater than a preset frequency threshold. If so, determine that there is a risk of jamming in the split type on-load tap-changer and generate a jamming warning; Based on the jamming warning, take an electrical interlock protection action to prohibit the operation of the split type on-load tap-changer.

[0013] Preferably, the method for determining whether there is continuous mechanical jamming caused by contact wear in the split type on-load tap-changer based on the contact wear degree data, and if so, taking a protection operation on the converter transformer, includes: Judge whether the contact wear degree data exceeds a preset wear range. If so, determine that there is continuous mechanical jamming caused by contact wear in the split type on-load tap-changer, and take a tripping protection operation on the converter transformer.

[0014] In a second aspect, an embodiment of the present invention provides a split type on-load tap-changer mechanical jamming fault detection system. The split type on-load tap-changer mechanical jamming fault detection system is applied to the split type on-load tap-changer mechanical jamming fault detection method as described above. The split type on-load tap-changer mechanical jamming fault detection system includes: A first judgment module, configured to obtain first current data of several circuits of the converter transformer during the operation of the converter transformer, and judge whether there is a missing transition resistance in the switch switching module based on the first current data; A data acquisition module, configured to receive a tap-changing command sent by a converter control system, control the converter transformer to perform a tap-changing process based on the tap-changing command, and collect the tap-changing delay time and tap-changing command response status of the tap-changing process; A second judgment module, configured to obtain second current data at monitoring positions of several tap-changing points of the converter transformer within an inter-stage short-circuit detection window corresponding to the tap-changing delay time, and judge whether there is an excessive short-circuit current peak caused by an excessive mechanical friction resistance in the switch switching module based on the second current data; A fault mode classification module, configured to obtain third current data of the tap-changing transformer from the operation module during the tap-changing process of the tap-changing transformer, and perform comparative analysis on the third current data to obtain a fault mode classification result of the switch switching module; An alarm generation module, configured to perform collaborative processing on the fault mode classification result and the tap-changing instruction response status to obtain a target alarm signal, where the target alarm signal includes fault location information of the switch switching module.

[0015] Compared with the prior art, the split-type on-load tap-changer mechanical jamming fault detection method and system in an embodiment of the present invention have the beneficial effects that: by obtaining first current data of several circuits to judge the missing situation of the transition resistance of the switch switching module, it is possible to timely discover abnormalities of key components, avoid serious problems such as current mutation caused by the missing transition resistance, and ensure the safety of the tap-changer switching operation; by collecting the tap-changing delay time and the tap-changing instruction response status, and combining the second current data of the monitoring positions of several tap-changing points within the inter-stage short-circuit detection window, it is possible to accurately judge whether the switch switching module causes the short-circuit current peak value to exceed the limit due to the excessive mechanical friction resistance, effectively preventing the expansion of the short-circuit fault caused by mechanical failure, and maintaining the stable operation of the tap-changing transformer and even the entire power system; it can not only accurately identify the fault mode, but also quickly locate the fault position, greatly shortening the fault handling time and improving the operation reliability and safety of the split-type on-load tap-changer. Description of the Drawings

[0016] Figure 1 is a flowchart of a split-type on-load tap-changer mechanical jamming fault detection method in an embodiment of the present invention; Figure 2 is a structural diagram of a split-type on-load tap-changer in an embodiment of the present invention; Figure 3 is a structural diagram of a flange in an embodiment of the present invention; Figure 4 is a flowchart of collaborative processing to obtain a target alarm signal in an embodiment of the present invention; Figure 5 is another flowchart of a split-type on-load tap-changer mechanical jamming fault detection method in an embodiment of the present invention; Figure 6 is a structural diagram of a split-type on-load tap-changer mechanical jamming fault detection system in an embodiment of the present invention; Reference Signs: 1. Switch switching module; 2. Switch selection module; 3. Flange; 4. Current transformer; H0~H4. Terminal posts. Detailed Embodiments

[0017] The following will further describe in detail the specific implementation manners of the present invention in conjunction with the accompanying drawings and embodiments. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0018] In the description of the present invention, it should be understood that the terms "first" and "second" etc. used in the present invention are used to distinguish different objects, rather than to describe a specific order.

[0019] In the description of the present invention, it should be noted that unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the art. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] As Figure 1 shown, an embodiment of the present invention provides a method for detecting mechanical jamming faults of a split-type on-load tap-changer, including the steps: It should be noted that the split-type on-load tap-changer is applied to a converter transformer, the converter transformer is applied to a high-voltage direct current transmission system, and the high-voltage direct current transmission system further includes a converter and a converter control system.

[0021] The split-type on-load tap-changer includes a switch switching module, a switch selection module, a flange, and an operating module. The flange is arranged between the switch switching module and the switch selection module, and the operating module is used to drive the switch switching module and the switch selection module to act to achieve gear switching.

[0022] As Figure 2 shown, the split-type on-load tap-changer includes a switch switching module 1 and a switch selection module 2. The bottom of the switch switching module is connected to one end of the flange 3 through a current-carrying conductor, and the other end of the flange 3 is connected to the switch selection module through a current-carrying conductor.

[0023] As Figure 2 or Figure 3 shown, a plurality of current transformers 4 are arranged in the flange. As Figure 3 shown, five terminals are arranged on the flange, namely H0, H1, H2, H3, and H4. The terminal H0 is not connected (shown in gray) to the current transformer. The terminals H1 and H2 are respectively the odd and even terminals of the first voltage regulating column of the converter transformer, and the terminals H3 and H4 are respectively the odd and even terminals of the second voltage regulating column of the converter transformer. The switch switching module is arranged in the secondary oil tank of the converter transformer, and the switch selection module is arranged in the main oil tank of the converter transformer. The secondary oil tank and the main oil tank of the converter transformer are completely isolated. It can be understood that the operating module is installed on the outer wall of the converter transformer oil tank and is connected to the switch body through relevant components to drive the switch to act.

[0024] The following specifically describes a method for detecting mechanical jamming faults of a split-type on-load tap-changer provided by an embodiment of the present invention: S1. During the operation of the converter transformer, obtain the first current data of several circuits of the converter transformer, and determine whether there is a missing transition resistance in the switch switching module based on the first current data; Specifically, step S1 includes: 1) During the operation of the converter transformer, obtain the first current signal of the primary circuit of the converter transformer and the second current signal of the secondary circuit of the converter transformer; During the operation of the converter transformer, the first current signal of the primary circuit of the converter transformer and the second current signal of the secondary circuit of the converter transformer are collected in real time through sensors. The primary circuit is the main circuit directly used for transmitting and transforming electric energy in the converter transformer. The secondary circuit is mainly used for controlling, protecting, measuring and signal transmission of the primary circuit, and ensures the safe and stable operation of the converter transformer by monitoring and controlling the electrical parameters of the primary circuit.

[0025] 2) Extract the spectral characteristics of the first current signal to obtain the high-frequency component of the first current signal; The fast Fourier transform is used to extract the spectral characteristics of the first current signal to obtain the high-frequency component and low-frequency component of the first current signal. The low-frequency component may reflect the normal operation state, and the high-frequency component may include abnormal fluctuations.

[0026] 3) Determine whether the amplitude of the high-frequency component is greater than the first preset threshold and whether the second current signal is less than the second preset threshold. If so, it is determined that there is a missing transition resistance in the switch switching module.

[0027] Determine whether the amplitude of the high-frequency component is greater than the first preset threshold. If so, it indicates that there are abnormal fluctuations, and further determine whether the second current signal is less than the second preset threshold. If so, it indicates that the current does not reach the expected level, and it is determined that there is a missing transition resistance in the switch switching module. It can be understood that poor contact or aging of components may both lead to missing transition resistance.

[0028] S2. Receive the tap-changing command sent by the converter control system, control the converter transformer to perform the tap-changing process based on the tap-changing command, and collect the tap-changing delay time and the response status of the tap-changing command during the tap-changing process; Specifically, the converter control system monitors parameters such as DC voltage, and issues a command to the converter transformer to adjust the tap according to the requirements and operating conditions of the HVDC transmission system, so that the trigger angle of the converter valve thyristor is within an appropriate range to ensure the stable operation of the HVDC transmission system.

[0029] Furthermore, step S2 includes: 1) Record the start time and end time of the gear shifting process, and characterize the difference between the end time and the start time as the gear shifting delay time; Use timestamps to record the time difference between the start and completion of gear shifting, and obtain the gear shifting delay time.

[0030] 2) After performing the gear shifting process, obtain the real-time mechanical operating state of the split type on-load tap-changer, and characterize the real-time mechanical operating state as the response state of the tap-changing command.

[0031] The real-time mechanical operating state of the split type on-load tap-changer includes but is not limited to the motor speed. In a specific embodiment, the converter control system issues a command to reduce the speed. After performing the gear shifting process, obtain the real-time motor speed of the split type on-load tap-changer, and characterize the real-time motor speed as the response state of the tap-changing command.

[0032] S3. Within the inter-stage short-circuit detection window corresponding to the gear shifting delay time, obtain the second current data at the monitoring positions of the converter transformer at several gear shifting points, and based on the second current data, determine whether there is an excessive short-circuit current peak caused by an excessive mechanical friction resistance in the switch switching module; Specifically, when the converter transformer is shifting gears, there are certain risks during the operation of the split type on-load tap-changer, such as poor contact of the contacts, insulation damage, etc., which may cause an inter-stage short-circuit fault. The inter-stage short-circuit detection window is to monitor relevant electrical quantities in real time during this time period to timely detect and determine whether an inter-stage short-circuit situation occurs.

[0033] Further, step S3 includes: 1) Obtain the third current signal at the monitoring position of the first gear shifting point of the converter transformer and the fourth current signal at the monitoring position of the second gear shifting point of the converter transformer; The current distribution inside the converter transformer varies at different positions. Especially during gear shifting, the current change characteristics at different parts have different values for fault judgment. By setting monitoring points at multiple positions, current information can be obtained more comprehensively and meticulously.

[0034] Specifically, in the present invention, there are two monitoring positions for gear shifting points inside the converter transformer, namely the monitoring position of the first gear shifting point and the monitoring position of the second gear shifting point. By monitoring the current change conditions at the corresponding positions, it can reflect the magnitude, change trend, etc. of the current at the corresponding positions at the moment of gear shifting and for a period of time after that.

[0035] 2) Determine whether both the third current signal and the fourth current signal are greater than the third preset threshold. If so, it is determined that there is an excessive short-circuit current peak caused by an excessive mechanical friction resistance in the switch switching module.

[0036] The current change during gear shifting should be within a certain range. If the mechanical friction resistance exceeds the standard, it may lead to abnormal switching process, and then cause the peak short-circuit current to exceed the normal range. By monitoring and comparing these current signals, it is possible to indirectly determine whether the mechanical friction resistance exceeds the standard and whether the peak short-circuit current limit is exceeded. Therefore, when both the third current signal and the fourth current signal are greater than the third preset threshold, it can be determined that there is a situation where the mechanical friction resistance of the switch switching module exceeds the standard and causes the peak short-circuit current limit to be exceeded.

[0037] S4. During the gear shifting process of the converter transformer, obtain the third current data of the converter transformer at the operation module, and conduct comparative analysis on the third current data to obtain the fault mode classification result of the switch switching module; The operation module, as the power source for switch operation, is equipped with necessary auxiliary devices such as limit, safety interlock, position indication, counting, and signal generator. Specifically, the operation module includes a motor and a transmission unit.

[0038] Further, step S4 includes: 1) Obtain the fifth current signal and the sixth current signal at both ends of the motor of the converter transformer; During the gear shifting process of the converter transformer, obtain the fifth current signal and the sixth current signal at both ends of the motor through sensors.

[0039] 2) Obtain the seventh current signal at the first detection point of the transmission unit of the converter transformer and the eighth current signal at the second detection point of the transmission unit of the converter transformer; During the gear shifting process of the converter transformer, obtain the seventh current signal at the first detection point of the transmission unit of the converter transformer and the eighth current signal at the second detection point of the transmission unit of the converter transformer through sensors.

[0040] 3) Conduct comparative analysis on the fifth current signal, the sixth current signal, the seventh current signal, and the eighth current signal based on the fourth preset threshold to obtain the first fault mode classification result of the switch switching module; Specifically, in this embodiment, the obtained fifth current signal is 5A, the sixth current signal is 4.8A, the seventh current signal is 6A, and the eighth current signal is 5.5A. By comparison, it is found that the difference between the seventh current signal and the eighth current signal is relatively large and the overall value is relatively high, indicating that there may be abnormal load in the transmission unit. Further, combined with the fourth preset threshold of 5.2A, it is determined that both the seventh current signal and the eighth current signal are greater than the fourth preset threshold, and then the first fault mode classification result of the switch switching module is determined as abnormal transmission resistance.

[0041] 4) Dynamically adjust the fourth preset threshold to obtain a dynamic current threshold, and optimize the first fault mode classification result based on the dynamic current threshold to obtain a second fault mode classification result; It should be noted that since the first fault mode classification result may not be accurate enough due to environmental interference, a dynamic threshold adjustment is adopted. In this embodiment, the fourth preset threshold is dynamically adjusted based on real-time temperature data to obtain a dynamic current threshold of 5.3 A. It is determined that both the seventh current signal and the eighth current signal are greater than the dynamic current threshold, and the first fault mode classification result is optimized based on the dynamic current threshold to obtain a second fault mode classification result of mechanical jamming.

[0042] 5) Characterize the second fault mode classification result as the fault mode classification result of the switch switching module.

[0043] After excluding the current fluctuations caused by temperature, this embodiment determines that the fault mode classification result of the switch switching module is mechanical jamming.

[0044] S5. Coordinate the fault mode classification result and the response status of the gear shifting instruction to obtain a target alarm signal.

[0045] Specifically, as Figure 4 shown, step S5 includes: S501. Generate an initial alarm signal based on the fault mode classification result; Extract features from the fault mode classification result and generate an initial alarm signal based on the extracted features, such as "the peak value reaches 15 A and the duration exceeds 3 seconds". Such a signal can be a simple light flash, and different colors represent different alarm priorities. Among them, red represents a high-priority alarm, intuitively reflecting the classification result.

[0046] S502. Determine whether the response status of the gear shifting instruction matches the preset mechanical operating state. If so, generate an intermediate alarm signal based on the initial alarm signal; In a specific embodiment, the converter control system issues an instruction to reduce the speed. After the gear shifting process, the motor speed of the split type on-load tap-changer should be reduced from 1000 revolutions per minute to 800 revolutions per minute. The real-time motor speed of the split type on-load tap-changer, that is, the response status of the gear shifting instruction, is obtained as 810 revolutions per minute, which is close to the preset mechanical operating state of 800 revolutions per minute, so it is determined to match. This matching judgment can effectively confirm the ability of the device to respond to instructions and avoid false alarms. Further, an intermediate alarm signal is generated according to the initial alarm signal. Compared with the initial alarm signal, the intermediate alarm signal carries more fault information, such as "current overload, duration 5 seconds".

[0047] S503. Perform clustering analysis on the intermediate alarm signal to obtain the fault location information of the switch switching module; The clustering algorithm is used to extract the fault location characteristics of the intermediate alarm signal, and the fault location information of the switch switching module is obtained.

[0048] S504. Based on the fault location information, the decision tree algorithm is used to optimize the intermediate alarm signal to obtain the target alarm signal.

[0049] Combined with the fault location information, the decision tree algorithm is used to optimize the intermediate alarm signal to obtain the target alarm signal in the final output form. It can be understood that the target alarm signal includes the fault location information of the switch switching module.

[0050] It should be noted that steps S1 - S5 reflect the mechanical jamming fault detection process of the switch switching module of the split type on-load tap-changer. To further process the fault, as Figure 5 shown, after step S5 of a split type on-load tap-changer mechanical jamming fault detection method in an embodiment of the present invention, the following steps are further included: S6. Obtain the real-time operation status data of the split type on-load tap-changer, and based on the real-time operation status data, determine whether there is a jamming risk for the split type on-load tap-changer. If so, stop the split type on-load tap-changer; Specifically, step S6 includes: 1) Obtain the real-time temperature data and real-time vibration frequency of the split type on-load tap-changer; The real-time operation status data of the split type on-load tap-changer, that is, the real-time temperature data and real-time vibration frequency, is obtained through sensors.

[0051] 2) Determine whether the real-time temperature data exceeds the preset temperature threshold or the real-time vibration frequency is greater than the preset frequency threshold. If so, it is determined that there is a jamming risk for the split type on-load tap-changer and a jamming warning is generated; The real-time temperature data reflects the heat generation situation of the split type on-load tap-changer, and the real-time vibration frequency reflects the operation stability of the split type on-load tap-changer. In this embodiment, the preset temperature threshold is 60 °C, and the preset frequency threshold is 10 Hz. If the real-time temperature data exceeds 60 °C or the real-time vibration frequency is greater than 10 Hz, it is determined that there is a jamming risk for the split type on-load tap-changer and a jamming warning is generated.

[0052] 3) Based on the jamming warning, take an electrical interlock protection action to prohibit the operation of the split type on-load tap-changer.

[0053] Based on the jamming warning, a relay is used to cut off the power supply path of the split type on-load tap-changer, thereby preventing the update of the operation status of the split type on-load tap-changer. This protection action can ensure the safety of the equipment in case of mechanical jamming faults.

[0054] Further, if it is determined based on the real-time operating state data that there is no longer a risk of jamming in the split type on-load tap-changer, the operation prohibition of the split type on-load tap-changer is lifted.

[0055] S7. Obtain the contact wear degree data of the split type on-load tap-changer, and determine whether there is continuous mechanical jamming caused by contact wear in the split type on-load tap-changer based on the contact wear degree data. If so, take protection operations on the converter transformer.

[0056] Obtain the contact wear degree data of the split type on-load tap-changer through a sensor, and determine whether the contact wear degree data exceeds the preset wear range. If so, it is determined that there is continuous mechanical jamming caused by contact wear in the split type on-load tap-changer, and trip protection operations are taken on the converter transformer.

[0057] Specifically, the contact wear degree data can be the contact wear depth. The key to determining whether the contact wear degree data exceeds the preset wear range lies in setting a reasonable threshold. In this embodiment, the preset wear range is 0 - 0.2 mm. If the contact wear degree data is 0.25 mm, which exceeds the preset wear range, it is determined that there is continuous mechanical jamming caused by contact wear in the split type on-load tap-changer, and trip protection operations are taken on the converter transformer, including tripping the incoming line breaker of the converter transformer and cutting off the operation of the cooler within the breaker tripping time, so as to ensure the safety of the converter transformer.

[0058] In the embodiment of the present invention, a method for detecting mechanical jamming faults of a split type on-load tap-changer can detect the missing situation of the transition resistance of the switch switching module by obtaining the first current data of several circuits, can timely discover the abnormality of key components, avoid serious problems such as current mutation caused by the missing transition resistance, and ensure the safety of the tap-changer switching operation; by collecting the gear shifting delay time and the response status of the gear shifting command, and combining the second current data of the monitoring positions of several gear shifting points within the inter-stage short-circuit detection window, it can accurately determine whether the switch switching module causes the short-circuit current peak value to exceed the limit due to the excessive mechanical friction resistance, effectively preventing the expansion of the short-circuit fault caused by mechanical faults and maintaining the stable operation of the converter transformer and even the entire power system; it can not only accurately identify the fault mode, but also quickly locate the fault position, greatly shortening the fault handling time and improving the operation reliability and safety of the split type on-load tap-changer.

[0059] As Figure 6 shown, the embodiment of the present invention provides a system for detecting mechanical jamming faults of a split type on-load tap-changer, which is applied to the method for detecting mechanical jamming faults of a split type on-load tap-changer as described above.

[0060] Specifically, the system for detecting mechanical jamming faults of a split type on-load tap-changer includes: The first judgment module 01 is configured to obtain first current data of several circuits of the converter transformer during the operation of the converter transformer, and judge whether there is a missing transition resistance in the switch switching module based on the first current data; The data acquisition module 02 is configured to receive a tap-changing instruction sent by the converter control system, control the converter transformer to perform a tap-changing process based on the tap-changing instruction, and collect the tap-changing delay time and the response status of the tap-changing instruction during the tap-changing process; The second judgment module 03 is configured to obtain second current data of the converter transformer at the monitoring positions of several tap-changing points within the inter-stage short-circuit detection window corresponding to the tap-changing delay time, and judge whether there is an excessive short-circuit current peak caused by an excessive mechanical friction resistance in the switch switching module based on the second current data; The fault mode classification module 04 is configured to obtain third current data of the converter transformer in the operation module during the tap-changing process of the converter transformer, and perform comparative analysis on the third current data to obtain a fault mode classification result of the switch switching module; The alarm generation module 05 is configured to perform collaborative processing on the fault mode classification result and the response status of the tap-changing instruction to obtain a target alarm signal, where the target alarm signal includes fault location information of the switch switching module.

[0061] It should be noted that each module in the above-mentioned split-type on-load tap-changer mechanical jamming fault detection system can be implemented in whole or in part by software, hardware, and their combination. The above-mentioned modules can be embedded in the processor of the computer device in hardware form or independent of it, or stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to the above-mentioned modules. For the specific limitations of a split-type on-load tap-changer mechanical jamming fault detection system, refer to the limitations of a split-type on-load tap-changer mechanical jamming fault detection method in the above text. The two have the same functions and effects, and will not be elaborated here.

[0062] In summary, for the split type on-load tap-changer mechanical jamming fault detection method and system according to the embodiments of the present invention, by obtaining the first current data of several circuits to judge the missing situation of the transition resistance of the switch switching module, it can timely detect the abnormality of key components, avoid serious problems such as current mutation caused by the missing transition resistance, and ensure the safety of the tap-changer switching operation; by collecting the gear switching delay time and the response status of the gear adjustment instruction, and combining the second current data of the monitoring positions of several gear switching points within the inter-stage short-circuit detection window, it can accurately judge whether the switch switching module causes the short-circuit current peak value to exceed the limit due to the excessive mechanical friction resistance, effectively preventing the expansion of the short-circuit fault caused by mechanical failure, and maintaining the stable operation of the converter transformer and even the entire power system; it can not only accurately identify the fault mode, but also quickly locate the fault position, greatly shortening the fault handling time and improving the operation reliability and safety of the split type on-load tap-changer.

[0063] Each embodiment in this specification is described in a progressive manner. For the parts that are the same or similar in each embodiment, reference can be made to each other. The key point of each embodiment is to illustrate the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and reference can be made to the partial description of the method embodiment for the relevant parts. It should be noted that the above-mentioned technical features of each embodiment can be combined arbitrarily. For the sake of concise description, not all possible combinations of the above-mentioned technical features in each embodiment are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0064] The above is only the preferred embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and replacements can still be made, and these improvements and replacements should also be regarded as the protection scope of the present invention.

Claims

1. A method for detecting mechanical jamming fault of a split-type on-load tap changer, characterized in that: The split on-load tap changer is applied to a converter transformer, and comprises a switch switching module, a switch selection module, a flange and an operation module, wherein the flange is arranged between the switch switching module and the switch selection module, and the operation module is used to drive the switch switching module and the switch selection module to realize gear switching; The split-type on-load tap changer mechanical jam fault detection method comprises: During the operation of the converter transformer, first current data of a plurality of loops of the converter transformer are obtained, and based on the first current data, whether there is a missing transition resistance in the switch switching module is determined; Receiving a gear shifting instruction sent by a converter control system, controlling the converter transformer to execute a gear shifting process based on the gear shifting instruction, and collecting a gear shifting delay time and a gear shifting instruction response state of the gear shifting process; In the inter-stage short-circuit detection window corresponding to the gear switching delay time, second current data of the converter transformer at a plurality of gear switching point monitoring positions are obtained, and based on the second current data, it is determined whether the switch switching module has excessive mechanical friction resistance causing the short-circuit current peak value to exceed the limit; During the gear switching of the converter transformer, third current data of the converter transformer in the operation module is obtained, and the third current data is compared and analyzed to obtain a fault mode classification result of the switch switching module; The fault mode classification result and the gear shift instruction response status are collaboratively processed to obtain a target alarm signal, wherein the target alarm signal includes the fault location information of the switch switching module.

2. The method for detecting mechanical jamming fault of a split-type on-load tap changer according to claim 1, characterized in that: After the failure mode classification result and the gear shift instruction response state are collaboratively processed to obtain a target alarm signal, the method further includes: Acquire real-time operating status data of the split on-load tap changer, and determine whether the split on-load tap changer has a risk of getting stuck based on the real-time operating status data, and if so, shut down the split on-load tap changer, wherein the real-time operating status data includes real-time temperature data and real-time vibration frequency; Acquire contact wear degree data of the split on-load tap changer, and determine whether the split on-load tap changer has contact wear that causes continuous mechanical jamming based on the contact wear degree data, and if so, take protective operation on the converter transformer.

3. The method for detecting mechanical jamming fault of split-type on-load tap changer according to claim 1, characterized in that: The method of obtaining first current data of a plurality of loops of the converter transformer during operation of the converter transformer and judging whether there is a transition resistance missing in the switch switching module based on the first current data includes: During the operation of the converter transformer, obtaining a first current signal of the converter transformer in the primary circuit and a second current signal of the converter transformer in the secondary circuit; Extracting frequency spectrum features of the first current signal to obtain a high-frequency component of the first current signal; It is determined whether the amplitude of the high-frequency component is greater than a first preset threshold and whether the second current signal is less than a second preset threshold. If so, it is determined that there is a transition resistance missing in the switch switching module.

4. The method for detecting mechanical jamming fault of a split on-load tap changer according to claim 1, characterized in that: The step of collecting the gear switching delay time and the gear shifting instruction response state during the gear switching process includes: Recording the start time and end time of the gear switching process, and characterizing the difference between the end time and the start time as the gear switching delay time; After executing the gear switching process, the real-time mechanical operation state of the split on-load tap changer is acquired, and the real-time mechanical operation state is characterized as a gear shift instruction response state.

5. The method for detecting mechanical jamming fault of split on-load tap changer according to claim 1, characterized in that: The step of obtaining the second current data of the converter transformer at a plurality of gear switching point monitoring positions, and judging based on the second current data whether the switch switching module has excessive mechanical friction resistance causing a short-circuit current peak value to exceed a limit, comprises: Acquire a third current signal of the converter transformer at a first gear switching point monitoring position and a fourth current signal of the converter transformer at a second gear switching point monitoring position; It is determined whether the third current signal and the fourth current signal are both greater than a third preset threshold value. If so, it is determined that the switch switching module has excessive mechanical friction resistance, causing the short-circuit current peak value to exceed the limit.

6. The method for detecting mechanical jamming fault of a split on-load tap changer according to claim 1, characterized in that: The operation module includes a motor and a transmission unit, and the obtaining of the third current data of the converter transformer in the operation module and the comparison and analysis of the third current data to obtain the fault mode classification result of the switch switching module include: Acquire a fifth current signal and a sixth current signal of the converter transformer at both ends of the motor; Acquire a seventh current signal of the converter transformer at a first detection point of the transmission unit and an eighth current signal of the converter transformer at a second detection point of the transmission unit; Comparatively analyzing the fifth current signal, the sixth current signal, the seventh current signal, and the eighth current signal based on a fourth preset threshold value to obtain a first fault mode classification result of the switch switching module; Dynamically adjusting the fourth preset threshold to obtain a dynamic current threshold, and optimizing the first fault mode classification result based on the dynamic current threshold to obtain a second fault mode classification result; The second fault mode classification result is characterized as a fault mode classification result of the switch switching module.

7. The method for detecting mechanical jamming fault of a split-type on-load tap changer according to claim 1, characterized in that: The coordinated processing of the fault mode classification result and the gear shift instruction response state to obtain a target alarm signal includes: generating an initial alarm signal based on the failure mode classification result; determining whether the gear shift instruction response state matches a preset mechanical operation state, and if so, generating an intermediate alarm signal based on the initial alarm signal; Performing cluster analysis on the intermediate alarm signal to obtain fault location information of the switch switching module; Based on the fault location information, a decision tree algorithm is used to optimize the intermediate alarm signal to obtain a target alarm signal.

8. The method for detecting mechanical jamming fault of a split-type on-load tap changer according to claim 2, characterized in that: The acquiring of real-time operating status data of the split on-load tap changer, and judging whether the split on-load tap changer has a risk of getting stuck based on the real-time operating status data, and if so, shutting down the split on-load tap changer, comprises: Acquiring real-time temperature data and real-time vibration frequency of the split-type on-load tap changer; Determine whether the real-time temperature data exceeds a preset temperature threshold or whether the real-time vibration frequency is greater than a preset frequency threshold, and if so, determine that the split-type on-load tap changer has a risk of getting stuck and generate a sticking warning; Based on the jam warning, an electrical locking protection action is taken to prohibit the split on-load tap changer from operating.

9. The method for detecting mechanical jamming fault of a split on-load tap changer according to claim 2, characterized in that: The method of judging whether the split on-load tap changer has contact wear that causes continuous mechanical jamming based on the contact wear degree data, and if so, taking protective actions on the converter transformer, includes: It is determined whether the contact wear degree data exceeds a preset wear range. If so, it is determined that contact wear of the split on-load tap changer causes continuous mechanical jamming, and a tripping protection operation is performed on the converter transformer.

10. A split-type on-load tap-changer mechanical jam fault detection system, characterized in that: The split-type on-load tap changer mechanical jam fault detection system is applied to the split-type on-load tap changer mechanical jam fault detection method according to any one of claims 1 to 9, and the split-type on-load tap changer mechanical jam fault detection system comprises: A first judgment module is used to obtain first current data of several loops of the converter transformer during the operation of the converter transformer, and judge whether there is a transition resistance missing in the switch switching module based on the first current data; A data acquisition module, used for receiving a gear shifting instruction sent by a converter control system, controlling the converter transformer to execute a gear shifting process based on the gear shifting instruction, and acquiring a gear shifting delay time and a gear shifting instruction response state during the gear shifting process; A second judgment module is used to obtain second current data of the converter transformer at a plurality of gear switching point monitoring positions within the inter-stage short-circuit detection window corresponding to the gear switching delay time, and judge whether there is a short-circuit current peak exceeding the limit due to excessive mechanical friction resistance of the switch switching module based on the second current data; A fault mode classification module, used for obtaining the third current data of the converter transformer in the operation module during the gear switching of the converter transformer, and performing comparative analysis on the third current data to obtain the fault mode classification result of the switch switching module; An alarm generation module is used to coordinately process the fault mode classification result and the gear shift instruction response status to obtain a target alarm signal, wherein the target alarm signal includes the fault location information of the switch switching module.

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