Converter transformer tap changer operating mechanism box health diagnosis system and method

Abstract

The present invention discloses a system and method for diagnosing the health of a converter transformer tap changer operating mechanism box in the field of high-voltage direct current transmission technology. The system comprises: receiving sampled data during the converter transformer's shifting process via an external sensor; determining the start and stop times of each node based on current criteria in the sampled data; comparing the start and stop times of each node with the on-off timing of a timing diagram to determine the deviation between the switch-on moment and the theoretical value; monitoring the current frequency characteristics of the switch-on moment to obtain the trend of current waveform signal changes; issuing a warning signal in response to the current waveform signal or the start and stop times of each node exceeding a warning value; and determining the degree of aging of the converter transformer components and locating faults based on the trend of current waveform signal changes, combined with an expert system for comprehensive analysis. Based on various raw data analysis and warnings, the present invention, in conjunction with the mechanism box action timing diagram, achieves comprehensive, all-round monitoring of all components of the mechanism box without blind spots.

Description

Technical Field

[0001] The present invention relates to a system and method for diagnosing the health of a converter transformer tap changer operating mechanism box, and belongs to the technical field of high-voltage direct current transmission. Background Art

[0002] High-voltage direct current (HVDC) transmission systems are increasingly becoming the leading solution for long-distance, high-capacity power transmission. The on-load tap-changer (OTC) adjustment frequency of the converter transformers used in these systems is significantly higher than that of traditional AC transformers. A reliable tap-changer operating mechanism box is crucial for smooth on-load tap-changer adjustment. Existing monitoring and protection mechanisms in operating mechanisms have simple logic and limited functionality, leading to frequent gear slippage incidents. To reduce gear slippage incidents and improve the reliability and stability of gear adjustment, a health diagnosis, monitoring, and early warning system for the converter transformer tap-changer operating mechanism box has become increasingly important. Summary of the Invention

[0003] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a health diagnosis system and method for the converter transformer tap changer operating mechanism box. Based on the analysis and early warning of various types of original data, combined with the mechanism box action timing diagram, all-round monitoring of all components of the mechanism box is achieved without blind spots.

[0004] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0005] In a first aspect, the present invention provides a method for diagnosing the health of a converter transformer tap changer operating mechanism box, comprising:

[0006] Receive sampling data during the converter transformer up / down process through an external sensor;

[0007] Determine the start and stop time of each node based on the current criterion in the sampled data;

[0008] Compare the start and stop time of each node with the on and off timing of the timing diagram to determine the deviation between the on and off timing and the theoretical value;

[0009] Monitor the current frequency characteristics at the moment of connection to obtain the change trend of the current waveform signal;

[0010] Sending a warning signal in response to the current waveform signal or when the start and stop time of each node exceeds the warning value;

[0011] According to the changing trend of the current waveform signal, combined with the comprehensive analysis of the expert system, the aging degree of components in the converter transformer is determined and the fault is located.

[0012] Furthermore, the external sensor is connected to the intelligent electronic device through a small signal board or different types of communication boards, wherein: the small signal board can switch to 4-20mA or 0-5V small signal mode, and the communication board can switch to RS485 or RS422 communication mode.

[0013] Furthermore, the external sensors include a current sensor, a torque sensor, an optical encoder and a spring pressure sensor, and the sampled data include current, torque, shaft rotation angle and braking performance data.

[0014] Furthermore, based on the trend of changes in the monitored current waveform signal and combined with the expert system comprehensive analysis, the degree of aging of components in the converter transformer is determined and the fault is located, including: by monitoring the trend of changes in the current waveform signal and analyzing the fluctuation of the on-off time of each node, the operating stability margin of each device is further quantified, and then combined with the time logic matrix, based on the difference analysis of the characteristics of different contacts of the same contactor and the trend of changes in the time coordination margin of different contactors, the relay coordination analysis of the entire gear shift process is realized to locate the aging or fault point.

[0015] Furthermore, the expert system uses embedded analysis models and historical data to intelligently determine the degree of component aging and locate faults, including tracking the dispersion trend of the brake disc's braking stop position, spectrum analysis of the motor / relay / contact starting impact current, and an actual relay delay prediction algorithm.

[0016] Furthermore, the expert system automatically records parameter changes with each operation data according to the current gear position and the initial fixed value library, and adaptively adjusts the warning value according to the change trend and change rate.

[0017] Furthermore, the diagnostic method also includes: receiving the hard contact signal of the mechanism box by opening the node, obtaining the auxiliary judgment signal, and providing the aging warning signal of the key components and the gear emergency stop control signal by opening the signal, wherein the auxiliary judgment signal includes the gear information, the tap changer position and the circuit breaker on / off signal.

[0018] In a second aspect, the present invention provides a health diagnosis system for a converter transformer tap changer operating mechanism box, comprising:

[0019] Data receiving module: used to receive sampling data during the converter transformer up / down process through an external sensor;

[0020] Time judgment module: used to judge the start and stop time of each node based on the current judgment in the sampled data;

[0021] Time determination module: used to compare the start and stop time of each node with the on and off timing of the timing diagram to determine the deviation between the on and off timing and the theoretical value;

[0022] Current detection module: used to monitor the current frequency characteristics at the time of connection and obtain the change trend of the current waveform signal;

[0023] Early warning module: used to issue an early warning signal in response to the current waveform signal or when the start and stop time of each node exceeds the early warning value;

[0024] Fault judgment module: used to determine the aging degree of components in the converter transformer and locate faults based on the changing trend of the current waveform signal combined with comprehensive analysis of the expert system.

[0025] In a third aspect, the present invention provides a device for diagnosing the health of a converter transformer tap changer operating mechanism box, comprising a processor and a storage medium;

[0026] The storage medium is used to store program instructions and a logic discrimination feature library;

[0027] The processor is configured to operate according to the instructions to execute the steps of any of the above methods.

[0028] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of any of the above methods when executed by a processor.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The health diagnosis system of this invention, through rational sensor configuration and combined with an expert diagnostic system, can flexibly monitor and diagnose various types of tap changer operating mechanism boxes. This diagnostic method enables comprehensive monitoring of various mechanisms, including motors, relays, and brake discs, through a rich set of interfaces. Time matrix logic enables comprehensive, real-time health diagnosis of delay relays with high failure rates, addressing the lack of comprehensive health diagnosis methods and slippage warning strategies for tap changer mechanisms in actual converter transformer operation. This enables relay aging and slippage warnings, thereby avoiding converter transformer slippage accidents and significantly improving converter transformer operational stability and tap changer operating mechanism box maintenance convenience. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a configuration diagram of the operating mechanism box health diagnosis system provided in the first embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the time matrix logic provided in the first embodiment of the present invention. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0034] Example 1:

[0035] This embodiment designs a method for diagnosing the health of the converter transformer tap changer operating mechanism box, wherein the system configuration is as follows: Figure 1 As shown, the time logic matrix diagram is as follows Figure 2 As shown in the figure, combined with the operation box action timing diagram and current sampling results, the current judgment determines the start and stop time of each node. The start and stop time of each node is then compared with the on-off timing of the timing diagram to determine the deviation between the connection time and the theoretical value. The current frequency characteristics of the connection time are also monitored, and the status of each device is comprehensively analyzed and evaluated. This method is implemented by an intelligent electronic device and an expert system running on the intelligent electronic device. The intelligent electronic device can flexibly configure external sensors such as current sensors, torque sensors, optical encoders, and spring pressure sensors through various access methods to achieve various monitoring functions, including current (including contact opening and closing), torque, angle, and braking performance. External sensors can be connected to the intelligent electronic device through different board configurations, including small signal boards (flexible switching of small signal modes such as 4-20mA and 0-5V) and communication boards (flexible switching of communication modes such as RS485 and RS422). The intelligent electronic device has input and output nodes. The expert system can monitor various physical quantities such as torque changes, current changes, and shaft rotation angle of the motor and main shaft during the converter transformer's up and down shifting process.

[0036] In this embodiment, the expert system can use embedded analysis models and historical data to intelligently determine the degree of component aging and locate faults, specifically including tracking the dispersed trend of the brake disc's braking stop position, spectrum analysis of the motor / relay / contact starting impact current, and actual relay delay prediction algorithm.

[0037] In this embodiment, the intelligent electronic device can not only be connected to various sensors, but also provides 20 input nodes for receiving hard contact signals of the mechanism box to obtain auxiliary judgment signals including gear information, tap changer position, circuit breaker on and off, etc.; and has 8 output signals for providing aging warning signals of key components and gear emergency stop control signals, etc.

[0038] In this embodiment, the current sensor can adopt a "passive CT + op amp" current sensor, or a zero-flux current sensor, and the sensor has a 0-5V signal output. The motor current monitoring sensor supports monitoring and sampling of a maximum current of 20A with an accuracy of <±2.0% FS; the relay / contact monitoring sensor supports monitoring and sampling of a current of 1A with an accuracy of <±0.5% FS. The system supports 24-channel sampling to realize waveform monitoring of motor current, relay current and contact on-off. For example, the relay on-off time is determined by the current / no current criterion, and the health status of the relay / contact mechanical structure is analyzed by the current waveform signal during the gear adjustment period. When the waveform, duration, etc. change significantly, the intelligent electronic device provides an early warning signal.

[0039] In this embodiment, the intelligent electronic device can monitor the on / off state of the contacts, accurately providing false alarms and refusal to operate alarms. Furthermore, by monitoring the changing trends of the current waveform signal and analyzing the fluctuations in the on / off duration of each node, the operating stability margin of each device can be further quantified. Furthermore, by combining the time logic matrix and analyzing the differences in contact characteristics of the same contactor and the changing trends in the time coordination margin of different contactors, relay coordination analysis can be performed throughout the entire shifting process, thereby accurately locating aging or fault points.

[0040] In this embodiment, the optical encoder is an RS422 access method with a maximum output frequency of 300kHz. The optical encoder can monitor the rotation angle of the drive shaft to determine whether the brake disc has rotated to the preset position, and can provide a brake disc position critical warning and a slip alarm based on the brake disc stop position change trend analysis. A warning signal is issued when the brake position is 3° away from the critical value, and an alarm signal is issued when it exceeds the critical value by 3°.

[0041] In this embodiment, the spring pressure sensor is a small signal of 4 to 20 mA, and can monitor a maximum elastic force of 100 kN. When the spring energy storage state pressure exceeds 5% of the historical data, an early warning signal is issued, and when it exceeds 10%, an alarm signal is issued.

[0042] In this embodiment, the expert system in the intelligent electronic device can grasp the motor current change trend during the shifting process through autonomous learning, and automatically record the parameter changes with each operation data based on the current gear position and the initial constant library, and adaptively adjust the warning value according to the change trend and change rate to avoid false alarms caused by environmental interference or normal aging.

[0043] The operating mechanism box health diagnosis method designed by the present invention can be applied to but not limited to the following aspects:

[0044] (1) The intelligent electronic device adapted to this diagnostic method can realize flexible configuration of various sensors through different board configurations, thereby being compatible with the operating mechanism boxes of converter transformer tap changers of various brands and comprehensively covering various monitoring points;

[0045] (2) This health diagnosis method is based on the early warning analysis of various raw data such as current, torque, on / off, spring pressure, etc., combined with the timing diagram of the mechanism box action and the time matrix logic to achieve all-round monitoring of all components of the mechanism box without blind spots. It can also locate potential fault points in a timely and accurate manner based on the aging characteristic curve of the components, and then provide a health assessment and maintenance guide for the relay.

[0046] Example 2:

[0047] The converter transformer tap changer operating mechanism box health diagnosis system can implement the converter transformer tap changer operating mechanism box health diagnosis method described in the first embodiment, including:

[0048] Data receiving module: used to receive sampling data during the converter transformer up / down process through an external sensor;

[0049] Time judgment module: used to judge the start and stop time of each node based on the current judgment in the sampled data;

[0050] Time determination module: used to compare the start and stop time of each node with the on and off timing of the timing diagram to determine the deviation between the on and off timing and the theoretical value;

[0051] Current detection module: used to monitor the current frequency characteristics at the time of connection and obtain the change trend of the current waveform signal;

[0052] Early warning module: used to issue an early warning signal in response to the current waveform signal or when the start and stop time of each node exceeds the early warning value;

[0053] Fault judgment module: used to determine the aging degree of components in the converter transformer and locate faults based on the changing trend of the current waveform signal combined with comprehensive analysis of the expert system.

[0054] Example 3:

[0055] The embodiment of the present invention further provides a device for diagnosing the health of a converter transformer tap changer operating mechanism box, which can implement the method for diagnosing the health of a converter transformer tap changer operating mechanism box described in the first embodiment, and includes a processor and a storage medium;

[0056] The storage medium is used to store program instructions and a logic discrimination feature library;

[0057] The processor is configured to operate according to the instructions to execute the steps of the following method:

[0058] Receive sampling data during the converter transformer up / down process through an external sensor;

[0059] Determine the start and stop time of each node based on the current criterion in the sampled data;

[0060] Compare the start and stop time of each node with the on and off timing of the timing diagram to determine the deviation between the on and off timing and the theoretical value;

[0061] Monitor the current frequency characteristics at the moment of connection to obtain the change trend of the current waveform signal;

[0062] Sending a warning signal in response to the current waveform signal or when the start and stop time of each node exceeds the warning value;

[0063] According to the changing trend of the current waveform signal, combined with the comprehensive analysis of the expert system, the aging degree of components in the converter transformer is determined and the fault is located.

[0064] Example 4:

[0065] An embodiment of the present invention further provides a computer-readable storage medium that can implement the method for diagnosing the health of a converter transformer tap changer operating mechanism box described in Example 1. The computer-readable storage medium stores a computer program that, when executed by a processor, implements the following method steps:

[0066] Receive sampling data during the converter transformer up / down process through an external sensor;

[0067] Determine the start and stop time of each node based on the current criterion in the sampled data;

[0068] Compare the start and stop time of each node with the on and off timing of the timing diagram to determine the deviation between the on and off timing and the theoretical value;

[0069] Monitor the current frequency characteristics at the moment of connection to obtain the change trend of the current waveform signal;

[0070] Sending a warning signal in response to the current waveform signal or when the start and stop time of each node exceeds the warning value;

[0071] According to the changing trend of the current waveform signal, combined with the comprehensive analysis of the expert system, the aging degree of components in the converter transformer is determined and the fault is located.

[0072] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0073] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0074] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0075] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0076] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for diagnosing the health of a converter transformer tap changer operating mechanism box, characterized in that: include: Receive sampling data during the converter transformer up / down process through an external sensor; Determine the start and stop time of each node based on the current criterion in the sampled data; Compare the start and stop time of each node with the on and off timing of the timing diagram to determine the deviation between the on and off timing and the theoretical value; Monitor the current frequency characteristics at the moment of connection to obtain the change trend of the current waveform signal; Sending a warning signal in response to the current waveform signal or when the start and stop time of each node exceeds the warning value; Specifically, a warning signal is issued when the waveform and duration of the current waveform signal change significantly; Based on the changing trend of the current waveform signal, combined with the expert system's comprehensive analysis, the degree of aging of components in the converter transformer is determined and faults are located. This includes: by monitoring the changing trend of the current waveform signal and analyzing the fluctuation of the on-off time of each node, the operating stability margin of each device is further quantified. Then, combined with the time logic matrix, based on the difference analysis of the different contact characteristics of the same contactor and the changing trend of the time coordination margin of different contactors, the relay coordination analysis of the entire gear shift process is realized to locate the aging or fault point.

2. The method for diagnosing the health of a converter transformer tap changer operating mechanism box according to claim 1, wherein: The external sensor is connected to the intelligent electronic device through a small signal board or different types of communication boards, wherein the small signal board can switch to 4~20mA or 0~5V small signal mode, and the communication board can switch to RS485 or RS422 communication mode.

3. The method for diagnosing the health of a converter transformer tap changer operating mechanism box according to claim 1, wherein: The external sensors include a current sensor, a torque sensor, an optical encoder and a spring pressure sensor, and the sampled data include current, torque, shaft rotation angle and brake performance data.

4. The method for diagnosing the health of a converter transformer tap changer operating mechanism box according to claim 1, wherein: The expert system uses embedded analysis models and historical data to intelligently determine the degree of component aging and locate faults, including tracking the dispersed trend of the brake disc's braking stop position, spectrum analysis of the motor / relay / contact starting inrush current, and an algorithm to predict the actual relay delay.

5. The method for diagnosing the health of a converter transformer tap changer operating mechanism box according to claim 1, wherein: The expert system automatically records parameter changes with each operation data according to the current gear position and the initial fixed value library, and adaptively adjusts the warning value according to the change trend and change rate.

6. The method for diagnosing the health of a converter transformer tap changer operating mechanism box according to claim 1, wherein: The diagnostic method further includes: receiving a hard contact signal of a mechanism box by opening an input node to obtain an auxiliary discrimination signal, and providing an aging warning signal of a key component and a gear emergency stop control signal by opening an output signal, wherein the auxiliary discrimination signal includes gear information, tap changer position, and circuit breaker on / off signal.

7. The health diagnosis system of the converter transformer tap changer operating mechanism box is characterized by: include: Data receiving module: used to receive sampling data during the converter transformer up / down process through an external sensor; Time judgment module: used to judge the start and stop time of each node based on the current judgment in the sampled data; Time determination module: used to compare the start and stop time of each node with the on and off timing of the timing diagram to determine the deviation between the on and off timing and the theoretical value; Current detection module: used to monitor the current frequency characteristics at the time of connection and obtain the change trend of the current waveform signal; Early warning module: used to issue an early warning signal in response to the current waveform signal or when the start and stop time of each node exceeds the early warning value; Specifically, a warning signal is issued when the waveform and duration of the current waveform signal change significantly; Fault determination module: used to determine the aging degree of components in the converter transformer and locate faults based on the changing trend of the current waveform signal and combined with comprehensive analysis of the expert system; The fault judgment module is specifically used to: further quantify the operating stability margin of each device by monitoring the changing trend of the current waveform signal and the fluctuation analysis of the on-off time of each node, and then combine it with the time logic matrix to analyze the difference in characteristics of different contacts of the same contactor and the changing trend of the time coordination margin of different contactors to realize the relay coordination analysis of the entire gear shifting process and locate the aging or fault point.

8. A device for diagnosing the health of a converter transformer tap changer operating mechanism box, characterized in that: including processors and storage media; The storage medium is used to store program instructions and a logic discrimination feature library; The processor is configured to operate according to the instructions to execute the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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