A GIS disconnector state diagnosis and early warning system and method based on transmission chain link double-position correlation monitoring

Abstract

This invention proposes a GIS disconnector switch status diagnosis and early warning system and method based on dual-position correlation monitoring of the transmission link. The system includes: a first position monitoring unit for acquiring the rotational position information of the crank arm output by the operating mechanism; a second position monitoring unit for acquiring the linear position information of the transmission link connected to the moving contact; and an intelligent analysis terminal. This invention constructs a theoretical transmission correlation model between the crank arm position and the link position, and calculates the correlation deviation between the actual position and the theoretical model in real time, thereby directly diagnosing the internal state of the transmission link. This correlation deviation can reflect latent faults that traditional single-point monitoring cannot detect, such as link loosening, plastic deformation, and pin wear. Simultaneously, based on the trend analysis of historical correlation deviations, early warning of progressive faults is achieved. This invention avoids the simple superposition of existing sensor technologies and provides a novel method for transmission link health diagnosis.

Description

Technical Field

[0001] This invention belongs to the field of condition monitoring technology for gas-insulated metal-enclosed switchgear (GIS), specifically relating to a GIS disconnector condition diagnosis and early warning system and method based on dual-position correlation monitoring of the transmission link. Background Technology

[0002] Gas-insulated metal-enclosed switchgear (GIS) is widely used in modern substations due to its high reliability. Among these, the open / closed position of the disconnecting switch is crucial for ensuring correct switching operations and the safe operation of the power grid.

[0003] Currently, determining whether a switch is in the correct position mainly relies on the following methods:

[0004] Mechanical position indicator: Installed on the output shaft of the operating mechanism, it only reflects the movement of the mechanism itself and cannot reflect the true state of the transmission link from the mechanism to the internal moving contact. When connecting parts such as transmission rods and pins become loose or deformed, even if the indicator shows that the position is in place, the internal contact may not be in place, posing a risk of "false position".

[0005] Electrical auxiliary switch signals: also driven by the operating mechanism shaft, and share the same defects as mechanical indicators;

[0006] Digital single-point monitoring: Existing technologies (such as CN107993877A) attempt to introduce angle sensors for digital monitoring of the crank arm. This type of solution still relies on single-point monitoring, only providing information on the output shaft of the mechanism, completely obscuring the status of the subsequent transmission links (connecting rods, couplings, etc.). When the connecting rod undergoes plastic bending, the pin wears, or the connection becomes loose, the crank arm position may be normal while the connecting rod end position deviates; single-point monitoring cannot detect such faults.

[0007] Furthermore, existing methods lack the ability to record and analyze operational process data, and cannot provide early warnings for progressive failures such as loose connecting rods and jammed mechanisms.

[0008] Therefore, there is an urgent need for a technical solution that can penetrate the blind spots of the transmission link and directly diagnose the health status of the entire transmission link from the mechanism to the contact. Summary of the Invention

[0009] The purpose of this invention is to propose a GIS disconnector status diagnosis and early warning system and method based on dual-position correlation monitoring of the transmission link, so as to overcome the technical defects of existing single-point monitoring schemes that cannot sense the internal status of the transmission link. This invention is not a simple superposition of two position sensors, but rather constructs a physical transmission correlation model between the two and uses the correlation deviation as a diagnostic indicator to achieve direct assessment of the health status of the transmission link.

[0010] To achieve the above objectives, the technical solution of the present invention is as follows:

[0011] A GIS disconnector status diagnosis and early warning system based on dual-position correlation monitoring of transmission links includes a first position monitoring unit, a second position monitoring unit, and an intelligent analysis terminal;

[0012] The first position monitoring unit is used to acquire the rotational position information of the output crank arm of the switch operating mechanism;

[0013] The second position monitoring unit is used to acquire the linear position information of the transmission link that is rigidly connected to the moving contact of the switch;

[0014] The intelligent analysis terminal is connected to the first location monitoring unit and the second location monitoring unit; the intelligent analysis terminal includes a data storage module and a microprocessor; the data storage module is used to store historical operation data; the microprocessor is configured to perform the following steps:

[0015] Based on the rotational position information and the linear position information, a standard correlation model representing the physical transmission relationship between the two under healthy conditions is constructed and stored.

[0016] After each switching operation, the correlation deviation between the actual obtained rotational position and linear position and the standard correlation model is calculated.

[0017] The presence of anomalies in the transmission link is determined based on the aforementioned correlation deviation.

[0018] Perform trend analysis on the correlation deviations of each operation and trigger early warnings based on the trend results.

[0019] Preferably, the standard correlation model is a transmission ratio model that describes the linear relationship between the crank arm rotation angle θ and the connecting rod linear displacement S:

[0020] S = k·θ + b

[0021] Among them, the transmission ratio coefficient k is determined by the inherent mechanical structure of the transmission link, and b is the intercept, which represents the initial offset or zero-position compensation value of the sensor installation. It is used to correct the inherent offset caused by the sensor installation position, so that the model can accurately describe the linear mapping relationship between the crank arm rotation angle and the connecting rod displacement.

[0022] Preferably, the correlation deviation is the actual measurement point ( , The straight line represented by the standard correlation model. Weighted distance .

[0023] Preferably, the weighted distance The calculation formula is:

[0024]

[0025] in The numerator represents the entire range of the connecting rod displacement, used for normalization; the numerator is a point ( , ) to the straight line The Euclidean distance, in the denominator Geometric factor make It becomes a dimensionless relative deviation index.

[0026] Preferably, the trend analysis includes: calculating the standard deviation or linear regression slope of the correlation deviation of the most recent N operations and using it as a trend indicator; when the trend indicator exceeds a preset threshold, it is determined as "deterioration of the transmission link status".

[0027] Preferably, the trend analysis includes: using a sliding window mechanism to construct an analysis window based on the correlation deviations of the most recent N operations, with a window length of N=10~20, calculating the standard deviation of the correlation deviations within the window, and triggering a "transmission link status deterioration" warning when the standard deviation exceeds a preset threshold three times consecutively.

[0028] Preferably, the microprocessor is further configured to: measure the operation time T during the switching operation, perform trend analysis on the operation time T of each operation, and trigger a "mechanism jamming" warning when the operation time continues to increase.

[0029] Preferably, the microprocessor is further configured to: measure the operation time T during the switching operation, perform trend analysis on the operation time T of each operation, and trigger a "mechanism jamming" warning if the current T value increases by more than a set percentage relative to the historical average.

[0030] Preferably, the first position monitoring unit uses a non-contact angle sensor, and the second position monitoring unit uses a non-contact displacement sensor; the intelligent analysis terminal communicates with the substation monitoring system via the IEC 61850 protocol.

[0031] A method for GIS disconnector status diagnosis and early warning based on dual-position correlation monitoring of transmission links, applied to any of the above-mentioned systems, includes the following steps:

[0032] Calibration steps: When the switch is in the precise closed and open positions, record the reference position data of the crank arm rotation angle θ and the connecting rod linear displacement S obtained by the first and second monitoring units respectively, and construct a standard correlation model under healthy conditions;

[0033] Diagnostic steps: After each switch operation, obtain the actual rotational position and linear position, and calculate the correlation deviation between the two position data and the standard correlation model; if the correlation deviation exceeds the first threshold, it is determined that there is an abnormality in the transmission link and an alarm is triggered.

[0034] Warning steps: Store the associated deviation of each operation into the historical database and perform trend analysis on the associated deviation sequence; determine whether to trigger the "transmission link status deterioration" warning based on the comparison results of the trend index and the second threshold.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. Different technical problems are solved: Existing technologies (including angle monitoring and displacement monitoring) only involve "single-point status indication" to determine whether the switch is in position, and cannot assess the internal health status of the transmission link; This invention proposes for the first time a monitoring scheme aimed at diagnosing the internal health of the transmission link, filling this technical gap.

[0037] 2. Not a simple superposition: This invention does not simply combine two known sensor technologies, but uses the inherent constraint relationship (transmission ratio) between the crank arm rotation angle and the connecting rod linear displacement to construct a new diagnostic index called "correlation deviation" for use in GIS disconnect switch status diagnosis and early warning.

[0038] 3. Detection of hidden faults: This invention can detect early faults that cannot be detected by traditional methods, such as slight bending of connecting rods and minor loosening of connecting parts.

[0039] 4. Trend early warning capability: Through trend analysis of historical correlation deviations, this invention can provide early warning of progressive failures, providing a reliable basis for condition-based maintenance and avoiding safety accidents caused by sudden failures.

[0040] 5. The correlation deviation defined in this invention Derived directly from the standard correlation model S = k·θ + b, it has a clear physical meaning—quantifying the degree of deviation between the actual transmission relationship and the inherent transmission ratio under healthy conditions, thus enabling direct diagnosis of internal state changes in the transmission link. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the system configuration of the present invention;

[0042] Figure 2 This is a schematic diagram of the installation of the first position monitoring (sensing) unit (rotary encoder) of the present invention;

[0043] Figure 3 This is a schematic diagram of the installation of the second position monitoring (sensing) unit (linear displacement sensor) of the present invention;

[0044] Figure 4 This is a flowchart of the intelligent analysis terminal's judgment and early warning logic of the present invention.

[0045] In the picture:

[0046] 1-Main connecting rod; 2-Rotary encoder mounting base; 3-Main crank arm; 4-High-precision rotary encoder; 5-Gear and transmission belt; 6-Isolating switch mechanism box; 7-Drive shaft; 8-Driven connecting rod; 9-Gas-insulated combined electrical appliance tank; 10-Connecting rod type linear displacement sensor; 11-Combined electrical appliance side mounting buckle; 12-Connecting rod side mounting buckle. Detailed Implementation

[0047] The following is in conjunction with the appendix Figure 1-4 The technical solution of the present invention will be described in detail below.

[0048] This invention proposes a GIS disconnector status diagnosis and early warning system based on dual-position correlation monitoring of the transmission link, comprising:

[0049] First position monitoring (sensing) unit: used to acquire the rotational position information of the crank arm output by the switch operating mechanism;

[0050] Second position monitoring (sensing) unit: used to acquire the linear position information of the transmission link that is rigidly connected to the moving contact of the switch;

[0051] The intelligent monitoring terminal is connected to the first and second location monitoring units and contains a data storage module and a microprocessor.

[0052] The microprocessor is configured to execute the following core logic:

[0053] Construct a standard correlation model: Under healthy equipment conditions, establish a standard correlation model (such as a linear transmission ratio model) based on the inherent mechanical transmission relationship between the crank arm position and the connecting rod position.

[0054] Calculate the correlation deviation: After each switching operation, compare the actual measured crank arm position and connecting rod position with the standard correlation model to calculate the correlation deviation. This deviation directly quantifies the overall deformation, loosening, or wear of the transmission link.

[0055] Status diagnosis: If the correlation deviation exceeds the preset threshold, it is determined that there is an abnormality in the transmission link and an alarm is issued.

[0056] Trend alert: Store the correlation deviations of each operation in the historical database, perform trend analysis (such as standard deviation and slope), and trigger an alert when the trend indicators deteriorate.

[0057] The present invention also provides a diagnostic and early warning method based on the above system, including a calibration step, a diagnostic step, and an early warning step.

[0058] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0059] Example 1: System Composition and Installation

[0060] like Figure 1 As shown, the system in this embodiment consists of a first location monitoring unit, a second location monitoring unit, and an intelligent analysis terminal.

[0061] The first position monitoring unit is used to acquire the rotational position of the crank arm output by the operating mechanism. In this embodiment, a high-precision multi-turn absolute rotary encoder (hereinafter referred to as "rotary encoder") is preferably used; its installation method is described in [reference needed]. Figure 2 .

[0062] Figure 2 middle:

[0063] Disconnecting switch mechanism box 6: Internally houses the operating mechanism and its transmission components.

[0064] Drive shaft 7: The output shaft of the operating mechanism, which is fixedly connected to the main crank arm and drives the crank arm to rotate.

[0065] Main crank arm 3: A rotating arm mounted on the drive shaft, which is the input end of the transmission link.

[0066] Main connecting rod 1: Hinged to the main crank arm, it converts the rotational motion of the crank arm into linear motion, driving the internal moving contact.

[0067] Rotary encoder mounting base 2: Fixed to the inner wall of the mechanism box or a suitable position to support the encoder.

[0068] High-precision rotary encoder 4: mounted on rotary encoder mounting base 2, its rotating shaft is connected to the transmission mechanism via a coupling.

[0069] Gear and transmission belt 5: The rotating shaft connecting the drive shaft 7 and the high-precision rotary encoder 4. By selecting an appropriate reduction ratio, the encoder rotating shaft rotates exactly one revolution when the main crank arm 3 completes its full stroke. This maps the sector angle of the crank arm to the full revolution angle of the encoder, maximizing and uniquely utilizing the angle stroke.

[0070] The second position monitoring unit is used to acquire the linear displacement of the transmission link rigidly connected to the moving contact. In this embodiment, a pull-rod type linear displacement sensor (LVDT, hereinafter referred to as "displacement sensor") is preferably used; its installation method is described in [reference needed]. Figure 3 .

[0071] Figure 3 middle:

[0072] Gas Insulated Switchgear (GIS) Tank 9: A closed metal shell that houses the moving contact of the disconnector and transmission components.

[0073] Driven link 8: Rigidly connected to the moving contact, it penetrates the tank wall, and its linear motion directly determines the opening and closing position of the moving contact. This link is the output end of the transmission link.

[0074] Linkage linear displacement sensor (LVDT) 10: Its housing is fixed to the tank by a mounting buckle, and the telescopic probe is connected to the driven link by a universal joint.

[0075] The mounting clip 11 on the side of the combined electrical appliance is welded or bolted to the GIS tank 9 and is used to install the housing end of the linkage linear displacement sensor 10.

[0076] Linkage side mounting buckle 12: fixed in the middle of the driven link 8, and hinged to the telescopic probe of the link-type linear displacement sensor 10 through a universal joint.

[0077] During installation, ensure that the line connecting the fixed point of the sensor housing and the connection point of the probe is parallel to the direction of movement of the driven link, and that the shortest length of the sensor is slightly greater than the minimum distance from the link to the housing when the switch is in the correct position. In this way, when the disconnecting switch is activated, the sensor is always in a unidirectional tension state, uniquely mapping the linear travel of the link to the tension travel of the sensor, thereby obtaining a high-precision displacement signal.

[0078] The signal lines of the high-precision rotary encoder 4 and the linkage-type linear displacement sensor 10 are connected to the intelligent analysis terminal installed next to the mechanism box. The terminal contains a signal processing module, a data storage module, a microprocessor, and a communication module (supporting the IEC 61850 protocol) for performing subsequent signal processing, status diagnosis, and trend early warning.

[0079] Example 2: Construction of a Standard Association Model (Core)

[0080] The core of this invention lies in not using two location data independently, but rather establishing a physical association model between them.

[0081] During the equipment commissioning phase, when the drive link is in good condition, perform multiple (e.g., 10) normal opening and closing operations. Record the corresponding data of the crank arm rotation angle θ and the connecting rod linear displacement S during each operation. Since the mechanical structure of the drive link is fixed, θ and S should satisfy a linear relationship:

[0082]

[0083] Where k is determined by the transmission ratio, and b is determined by the initial installation position.

[0084] The standard correlation model parameters (k, b) under healthy conditions are obtained by fitting using the least squares method, and the model is stored in the data storage module. This model represents the "inherent transmission characteristics" when the transmission link is intact.

[0085] Example 3: Correlation Deviation Calculation and Status Diagnosis

[0086] In the standard association model After the system is established, the intelligent analysis terminal obtains the actual measurement point after each switch operation. , The calculation of correlation bias involves three steps:

[0087] Step 1: Calculate the theoretical displacement

[0088] Measured crank arm angle Substituting into the standard correlation model, we obtain the theoretical link displacement:

[0089]

[0090] Step 2: Calculate the deviation between the actual displacement and the theoretical displacement.

[0091] actual displacement With theoretical displacement The difference is:

[0092]

[0093] The difference This directly reflects a comprehensive anomaly in the transmission link. When the transmission link is intact, It should be close to zero; when the connecting rod bends, the connection becomes loose, or the pin wears, It will deviate significantly from zero.

[0094] Step 3: Normalize to obtain the dimensionless correlation bias

[0095] Define the correlation deviation for:

[0096]

[0097] in The full range of the linkage displacement (i.e., the process from opening to closing) (The change in quantity). This dimensionless index facilitates cross-device comparisons and threshold setting.

[0098] Diagnostic logic:

[0099] like If ≤ Th1 (first threshold), the transmission link is considered normal;

[0100] like > Th1 determines that there is an abnormality in the transmission link (such as bent connecting rod, loose connection, worn pin) and immediately issues an alarm signal.

[0101] Example 4: Trend Early Warning

[0102] The correlation deviation calculated for each operation Store the data in the historical database in chronological order, forming a sliding window of length N (N is recommended to be 10~20).

[0103] Calculate the standard deviation of the D value within the window. :

[0104]

[0105] Early warning logic:

[0106] when When Th2 (the second threshold) is reached, it indicates that the repeatability of the transmission link has deteriorated, triggering a "transmission link condition deterioration" warning. The possible causes are increased wear gaps or worsened loosening of connections.

[0107] when When the value continues to increase (e.g., three consecutive operations all exceed the previous value), a "trend deterioration" warning is triggered, and maintenance is recommended.

[0108] Optionally, the operation time T for each operation can be monitored simultaneously, and the historical average of T can be calculated. If the current T exceeds the average by more than 20%, an auxiliary warning for "institutional stagnation" is triggered.

[0109] Example 5: Complete Operation Process

[0110] Initialization: The system powers on and loads the standard association model (k, b) and historical data.

[0111] Waiting operation: Monitor the switch status in real time and wait for the opening / closing operation to be triggered.

[0112] Data acquisition: During the operation, θ(t) and S(t) are recorded at a sampling rate of not less than 100Hz.

[0113] Position determination: When both θ and S are stable within the allowable range of the target position, the operation is determined to be complete.

[0114] Correlation deviation calculation: after reading stabilizes and ,calculate .

[0115] Real-time diagnosis: If > Th1, immediately output "Transmission link abnormal" alarm.

[0116] History Updates: This time The operation time Ti is stored in the historical database, and the sliding window is updated.

[0117] Trend Analysis: Calculation If it exceeds Th2, output a "state degradation" warning.

[0118] Loop: Return to step 2.

[0119] The above description is merely a preferred embodiment of the present invention and does not limit the scope of the patent. Any modifications, equivalent substitutions, improvements, etc., made within the concept and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A GIS disconnector status diagnosis and early warning system based on dual-position correlation monitoring of transmission links, characterized in that, It includes a first location monitoring unit, a second location monitoring unit, and an intelligent analysis terminal; The first position monitoring unit is used to acquire the rotational position information of the output crank arm of the switch operating mechanism; The second position monitoring unit is used to acquire the linear position information of the transmission link that is rigidly connected to the moving contact of the switch; The intelligent analysis terminal is connected to the first location monitoring unit and the second location monitoring unit; the intelligent analysis terminal includes a data storage module and a microprocessor; the data storage module is used to store historical operation data; the microprocessor is configured to perform the following steps: Based on the rotational position information and the linear position information, a standard correlation model representing the physical transmission relationship between the two under healthy conditions is constructed and stored. After each switching operation, the correlation deviation between the actual obtained rotational position and linear position and the standard correlation model is calculated. The presence of anomalies in the transmission link is determined based on the aforementioned correlation deviation. Perform trend analysis on the correlation deviations of each operation and trigger early warnings based on the trend results.

2. The GIS disconnector status diagnosis and early warning system according to claim 1, characterized in that, The standard correlation model is a transmission ratio model that describes the linear relationship between the crank arm rotation angle θ and the connecting rod linear displacement S: S = k·θ + b Among them, the transmission ratio coefficient k is determined by the inherent mechanical structure of the transmission link, and b is the intercept, which represents the initial offset or zero-position compensation value of the sensor installation. It is used to correct the inherent offset caused by the sensor installation position, so that the model can accurately describe the linear mapping relationship between the crank arm rotation angle and the connecting rod displacement.

3. The GIS disconnector status diagnosis and early warning system according to claim 1, characterized in that, The correlation deviation is the actual measurement point ( , The straight line represented by the standard correlation model. Weighted distance .

4. The GIS disconnector status diagnosis and early warning system according to claim 3, characterized in that, The weighted distance The calculation formula is: in The numerator represents the entire range of the connecting rod displacement, used for normalization; the numerator is a point ( , ) to the straight line The Euclidean distance, in the denominator Geometric factor make It becomes a dimensionless relative deviation index.

5. The GIS disconnector status diagnosis and early warning system according to claim 1, characterized in that, The trend analysis includes: calculating the standard deviation or linear regression slope of the correlation deviation of the most recent N operations and using it as a trend indicator; when the trend indicator exceeds a preset threshold, it is determined as "deterioration of the transmission link status".

6. The GIS disconnector status diagnosis and early warning system according to claim 1, characterized in that, The trend analysis includes: using a sliding window mechanism, constructing an analysis window based on the correlation deviation of the most recent N operations, with a window length of N=10~20, calculating the standard deviation of the correlation deviation within the window, and triggering a "transmission link status deterioration" warning when the standard deviation exceeds a preset threshold three times consecutively.

7. The GIS disconnector status diagnosis and early warning system according to claim 1, characterized in that, The microprocessor is also configured to: measure the operation time T during the switching operation, perform trend analysis on the operation time T of each operation, and trigger a "mechanism jamming" warning when the operation time continues to increase.

8. The GIS disconnector status diagnosis and early warning system according to claim 1, characterized in that, The microprocessor is also configured to: measure the operation time T during the switching operation and perform trend analysis on the operation time T of each operation; if the current T value increases by more than a set percentage relative to the historical average, trigger a "mechanism jamming" warning.

9. The GIS disconnector status diagnosis and early warning system according to claim 1, characterized in that, The first position monitoring unit uses a non-contact angle sensor, and the second position monitoring unit uses a non-contact displacement sensor; the intelligent analysis terminal communicates with the substation monitoring system via the IEC 61850 protocol.

10. A method for GIS disconnector status diagnosis and early warning based on dual-position correlation monitoring of transmission links, applied to the system described in any one of claims 1 to 7, characterized in that, Includes the following steps: Calibration steps: When the switch is in the precise closed and open positions, record the reference position data of the crank arm rotation angle θ and the connecting rod linear displacement S obtained by the first and second monitoring units respectively, and construct a standard correlation model under healthy conditions; Diagnostic steps: After each switch operation, obtain the actual rotational position and linear position, and calculate the correlation deviation between the two position data and the standard correlation model; if the correlation deviation exceeds the first threshold, it is determined that there is an abnormality in the transmission link and an alarm is triggered. Warning steps: Store the associated deviation of each operation into the historical database and perform trend analysis on the associated deviation sequence; determine whether to trigger the "transmission link status deterioration" warning based on the comparison result of the trend index and the second threshold.

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