A harmonic monitoring system and method for a wall bushing in a flexible DC converter station

Abstract

The present invention discloses a harmonic monitoring system and method for a wall bushing in a flexible direct current converter station, which relates to the technical field of harmonic monitoring in power systems. The system comprises a capacitor voltage divider component, which is connected in series with a main capacitor of the wall bushing for voltage division; a broadband current sensing component, which is annularly arranged on the outer wall of the bushing between the bushing end screen tap and the capacitor voltage divider component, and is connected to a data acquisition component; the data acquisition component is connected to the capacitor voltage divider component and the broadband current sensing component, performs synchronous sampling, filtering, wavelet transform, harmonic modeling and feature extraction, and uploads the results to a data analysis background; the data analysis background is communicatively connected to the data acquisition component, is used to receive the uploaded data frames, and cooperates with an interactive interface to display harmonic monitoring information; the system of the present invention realizes the linkage between structural coupling modeling and synchronous acquisition of high-frequency signals, constructs a multi-channel harmonic monitoring closed-loop path, and improves the integrity of monitoring and the synergy of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of power system harmonic monitoring, and in particular to a harmonic monitoring system and method for a wall bushing of a flexible direct current converter station. Background Art

[0002] As core infrastructure for building a new type of DC grid, the operational stability of flexible DC converter stations is directly related to the safety and reliability of high-voltage DC transmission systems. Wall bushings, critical transition components for electrical isolation and transmission inside and outside the converter station, must withstand the high-frequency currents, harmonic disturbances, and complex electromagnetic coupling caused by high-speed switching.

[0003] Based on existing engineering experience, local hotspots and high-frequency harmonic concentrations are prone to forming in wall bushing structures, particularly along the distributed capacitance path between the end screen and the ground, and at the interfaces between conductors. These can easily lead to insulation degradation, corona discharge, and localized arcing. Traditional monitoring methods often use wired current transformers, voltage sensors, or single-point magnetic flux sampling devices. These methods are limited in installation location and have a narrow measurement range. Furthermore, long-distance wiring is highly susceptible to power frequency interference, ground stray currents, and lightning surges, which can distort or mask harmonic information. Most existing harmonic monitoring systems operate within a frequency band below 2 kHz, making them unable to effectively sense and extract high-frequency transient disturbances (especially above 10 kHz), making accurate identification and invasive diagnosis difficult during the early stages of critical equipment operation. Some literature proposes using sensing mechanisms such as fiber Bragg gratings and microring resonators to demodulate harmonics, but these methods suffer from limited stability, high cost, and weak coupling. Other studies have proposed using multi-channel digital filtering to separate the signal spectrum, but these algorithms rely on preset templates and lack the ability to adaptively model complex, nonstationary harmonics. At the same time, existing studies often ignore the strong coupling relationship between the structural characteristics of wall bushings (such as length, capacitance distribution, and material dielectric constant) and high-frequency signal propagation, making it impossible to identify abnormal hotspot distribution or local energy concentration areas based on structural distribution. Traditional monitoring methods often rely on fixed thresholds to determine abnormal conditions, without considering the coupling effects of ambient temperature and humidity and load conditions on harmonic characteristics under different operating conditions, which can easily lead to false alarms and missed alarms. Data analysis is often performed in the cloud, which lacks real-time performance and edge processing capabilities, and cannot meet the needs of on-site distributed early warning. Therefore, in the harmonic monitoring scenario of wall bushings in flexible DC converter stations, there is an urgent need for a comprehensive monitoring solution that integrates structural perception, signal feature analysis, adaptive threshold adjustment, and edge collaborative computing. Summary of the Invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the technical problems solved by the present invention are: the existing monitoring system has problems such as incomplete sampling path construction, insufficient monitoring frequency band coverage, structural parameters not involved in modeling, and delayed judgment and response mechanism, low signal processing real-time performance, low positioning resolution, and lack of interactive closed loop, as well as how to realize a harmonic monitoring system for wall bushings in flexible DC converter stations based on synchronous acquisition of high-frequency signals, structural coupling modeling and adaptive criterion linkage.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a harmonic monitoring system for a wall bushing in a flexible DC converter station, comprising a capacitor voltage divider component, which is connected in series with the main capacitor of the wall bushing for voltage division; a broadband current sensing component, which is annularly arranged on the outer wall of the bushing between the bushing end screen tap and the capacitor voltage divider component, and is connected to a data acquisition component; the data acquisition component is connected to the capacitor voltage divider component and the broadband current sensing component, performs synchronous sampling, filtering, wavelet transform, harmonic modeling and feature extraction, and uploads the results to a data analysis background; the data analysis background is communicatively connected to the data acquisition component, is used to receive uploaded data frames, and cooperates with the interactive interface to display harmonic monitoring information.

[0007] As a preferred solution of the harmonic monitoring system for the wall bushing of the flexible DC converter station described in the present invention, the capacitive voltage divider component includes a capacitive voltage divider and a main capacitor of the wall bushing in series, which is installed between the end screen and the grounding structure through an insulating support and connected to the signal transmission path through an isolator for electrical isolation sampling.

[0008] As a preferred solution of the harmonic monitoring system for the wall bushing of the flexible DC converter station described in the present invention, the broadband current sensing component includes multiple broadband current sensors arranged equidistantly around the bushing conductor, with a response bandwidth covering 1 kHz to 10 MHz. Each sensor is respectively connected to the corresponding acquisition channel of the data acquisition component to receive a unified synchronous control signal.

[0009] As a preferred solution of the harmonic monitoring system for the wall bushing of the flexible DC converter station described in the present invention, the data acquisition component includes an analog-to-digital conversion module, an adaptive filtering module and an edge processing module; the analog-to-digital conversion module includes receiving control signals transmitted by the capacitor voltage divider component and the broadband current sensing component and digitally converting them into acquisition signals; the adaptive filtering module includes real-time denoising of the acquisition signals through an adaptive filtering algorithm; and the edge processing module includes a wavelet analysis and harmonic structure modeling unit, a threshold judgment unit, and a fault location unit.

[0010] As a preferred solution of the harmonic monitoring system for the wall bushing of the flexible DC converter station described in the present invention, the wavelet analysis and harmonic structure modeling unit includes performing multi-scale wavelet decomposition on the collected signal through wavelet analysis to extract frequency characteristic data of different frequency bands; establishing a bushing harmonic coupling model based on the geometric dimensions and material dielectric constant of the bushing, and mapping the frequency characteristic data to form a harmonic characteristic vector.

[0011] As a preferred solution of the harmonic monitoring system for the wall bushing of the flexible DC converter station described in the present invention, the threshold judgment unit includes receiving a harmonic feature vector, obtaining environmental parameter information based on an internal temperature monitoring probe, performing statistical calculations based on a sliding window, constructing an adaptive threshold model, and outputting an abnormality mark and a positioning request instruction.

[0012] As a preferred solution of the harmonic monitoring system for the wall bushing of the flexible DC converter station described in the present invention, the fault location unit includes: the fault location unit is internally communicated with the edge processing module, receives the abnormality mark and positioning request instruction of each channel, and generates a positioning tag through spatial mapping and change trend comparison.

[0013] As a preferred solution of the harmonic monitoring system for the wall bushing of the flexible DC converter station described in the present invention, the edge processing module further includes packaging the harmonic feature vector, anomaly mark, and positioning tag of each node into a communication data frame. The data frame fields include sampling timestamp, frequency amplitude, anomaly mark point, and node threshold status, and uploading the data to the data analysis background via a fiber optic communication link.

[0014] As a preferred solution of the harmonic monitoring system for the wall bushing of the flexible DC converter station described in the present invention, the data analysis background includes a data parsing module and an interactive display module; the data parsing module is used to parse the uploaded data frame fields and generate a structured data set; the interactive display module is used to graphically display the frequency amplitude diagram, abnormal marking points and abnormal labels, and at the same time provides historical record retrieval, manual marking and abnormal confirmation operation interfaces.

[0015] Another object of the present invention is to provide a harmonic monitoring method for wall bushings in flexible DC converter stations. By introducing edge processing linked with wavelet analysis and structural modeling, the method solves the problem that current harmonic monitoring technologies do not incorporate bushing structural parameters and cannot generate computable harmonic eigenvectors.

[0016] As a preferred solution of the harmonic monitoring method for the wall bushing of the flexible DC converter station described in the present invention, it includes: constructing a signal acquisition path through a capacitor voltage divider component and a broadband current sensing component, receiving voltage and current signals through an analog-to-digital conversion module, and performing synchronous sampling and digital processing; based on an adaptive filtering module and an edge processing module, performing wavelet decomposition on the acquired signal to generate a harmonic feature vector, combining with an internal temperature monitoring probe to obtain parameter statistics and calculate, and outputting an abnormality mark and a positioning request instruction; based on a fault location unit, performing a positioning and identification operation on the abnormal mark, encapsulating the harmonic feature vector, the abnormality mark and the positioning tag into a communication data frame, and uploading it to the data analysis background via a fiber optic communication link.

[0017] A computer device includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement a harmonic monitoring system for a wall bushing of a flexible DC converter station.

[0018] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a harmonic monitoring system for a wall bushing in a flexible DC converter station.

[0019] Beneficial effects of the present invention: The harmonic monitoring system for the wall bushing of the flexible DC converter station provided by the present invention realizes stable acquisition of the primary voltage of the wall bushing by constructing a signal acquisition path in which a capacitor voltage divider and a main capacitor are connected in series; by arranging a broadband current sensor array on the outer wall of the conductor and adopting a multi-channel synchronization mechanism, spatial collaborative acquisition of high-frequency current signals is realized; an extraction process constructed by combining adaptive filtering and wavelet transform is used to separate high-frequency non-stationary signals under complex backgrounds; a bushing harmonic coupling model is established in combination with structural parameters to generate characteristic vectors related to structural response to achieve matching expression between signals and physical structures; environmental parameters are introduced to construct an adaptive threshold model to achieve adaptive judgment under operating conditions; multi-node frequency domain information is integrated to realize edge positioning and early warning, and graphical display is completed through the communication channel linkage main control interface; the present invention achieves better results in acquisition accuracy, modeling expression and real-time diagnosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 This is an overall schematic diagram of a harmonic monitoring system for a wall bushing in a flexible DC converter station provided in Example 1 of the present invention.

[0022] Figure 2 This is a structural schematic diagram of a harmonic monitoring system for a wall bushing in a flexible DC converter station provided in Example 1 of the present invention.

[0023] Figure 3 This is an overall flow chart of a harmonic monitoring method for a wall bushing in a flexible DC converter station provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0024] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in this field without creative work should fall within the scope of protection of the present invention.

[0025] Example 1, with reference to Figure 1-Figure 2 , as one embodiment of the present invention, provides a harmonic monitoring system for a wall bushing in a flexible DC converter station, comprising:

[0026] S1: Capacitor voltage dividing component 100, connected in series with the main capacitor C of the wall bushing for voltage division.

[0027] Furthermore, the capacitive voltage divider component 100 includes a capacitive voltage divider C_div and a wall bushing main capacitor C connected in series, which is installed between the end screen and the grounding structure through an insulating support and connected to the signal transmission path through an isolator B for electrical isolation sampling.

[0028] It should be noted that if Figure 2 As shown, during the installation process, the main capacitor C of the wall bushing is first connected in series on one side of the end screen tap of the wall bushing, and a capacitor voltage divider C_div is fixedly arranged between the end screen tap S of the wall bushing on the other side and the ground to form a series capacitor channel, which is mechanically supported in the bushing structure by an insulating support device; then the isolator B is connected in parallel with the voltage divider output to form an electrical isolation interface, thereby realizing the undisturbed extraction of the high-frequency voltage signal. Without direct electrical conduction with the primary side, the voltage signal is sent to the analog-to-digital conversion module in the data acquisition component 300 through a signal shielded cable, realizing data input in parallel with the high-frequency current sampling path.

[0029] It should also be noted that the capacitive voltage divider C_div and the main capacitor C of the wall bushing are constructed into a local high-frequency harmonic sampling circuit, and contactless signal isolation is achieved through the isolator B, which is then led out to the data acquisition component. This breaks through the traditional through-wall capacitance measurement system that requires disconnecting the cable or installing a compensation coil. While ensuring that the original structure of the bushing remains unchanged, it achieves continuous high-frequency response acquisition of the primary voltage of the wall bushing, provides voltage support input for subsequent filtering and harmonic modeling, and improves the system structure integration and adaptability to on-site deployment.

[0030] S2: a broadband current sensing component 200, which is annularly arranged on the outer wall of the bushing between the bushing end screen tap S and the capacitive voltage divider component 100, and is connected to the data acquisition component 300.

[0031] Furthermore, the broadband current sensing component 200 includes multiple broadband current sensors I, which are equidistantly arranged around the bushing conductor, with a response bandwidth covering 1kHz to 10MHz. Each sensor is connected to a corresponding acquisition channel of the data acquisition component 300 to receive a unified synchronous control signal.

[0032] It should be noted that if Figure 2 As shown, the number and spacing of sensors are determined according to the structural dimensions of the bushing. The broadband current sensor I is physically fixed between the bushing end screen tap S and the ground lead-out area by detachable clamping or magnetic attraction. A shielded signal cable is laid and connected to the data acquisition component 300. The initialization, activation, and response window times of each channel are uniformly and synchronously set. The analog-to-digital conversion module completes current signal sampling and transfers it to the digital processing flow.

[0033] It should also be noted that by setting up a multi-point broadband current sensor array on the outer wall of the casing and combining it with a unified synchronous control mechanism, a multi-dimensional synchronous acquisition architecture for high-frequency signals is realized, which can obtain the difference characteristics of high-frequency signals at different spatial positions and provide structural basic data input for subsequent edge processing modules to perform fault location and anomaly identification.

[0034] S3: The data acquisition component 300 is connected to the capacitor voltage divider component 100 and the broadband current sensing component 200, performs synchronous sampling, filtering, wavelet transformation, harmonic modeling and feature extraction, and uploads the results to the data analysis background 400.

[0035] Furthermore, the data acquisition component 300 includes an analog-to-digital conversion module, an adaptive filtering module and an edge processing module; the analog-to-digital conversion module includes receiving the control signal transmitted by the capacitor voltage divider component 100 and the broadband current sensing component 200 and digitally converting it into an acquisition signal; the adaptive filtering module includes real-time denoising of the acquisition signal through an adaptive filtering algorithm; the edge processing module includes a wavelet analysis and harmonic structure modeling unit, a threshold judgment unit, and a fault location unit.

[0036] It should be noted that the wavelet analysis and harmonic structure modeling unit includes performing multi-scale wavelet decomposition on the collected signal through wavelet analysis to extract frequency characteristic data of different frequency bands; establishing a casing harmonic coupling model based on the geometric dimensions and material dielectric constant of the casing, and mapping the frequency characteristic data to form a harmonic characteristic vector.

[0037] It should also be noted that the threshold judgment unit includes receiving harmonic feature vectors, obtaining environmental parameter information based on the internal temperature monitoring probe T, performing statistical calculations based on a sliding window, building an adaptive threshold model, and outputting an abnormality mark and positioning request instructions.

[0038] It should also be noted that the fault location unit includes: the fault location unit is internally communicated with the edge processing module, receives each channel abnormality mark and location request instruction, and generates a location tag through spatial mapping and change trend comparison.

[0039] It should also be noted that the edge processing module also includes packaging the harmonic feature vector, anomaly mark and positioning label of each node into a communication data frame. The data frame fields include sampling timestamp, frequency amplitude, anomaly mark point, node threshold status, and uploading it to the data analysis background 400 via the optical fiber communication link.

[0040] It should also be noted that after power-on initialization, the analog-to-digital conversion channel is synchronously configured, the sampling timestamp between each broadband current sensor I is activated, the control signal enters the analog-to-digital conversion module, the synchronous digitization of the high-frequency voltage / current is completed, and it is converted into an acquisition signal, and enters the adaptive filtering module in real time. The adaptive filtering algorithm dynamically adjusts the filter coefficient according to the noise situation, and sends it to the wavelet analysis and harmonic structure modeling unit for decomposition. After extracting the frequency characteristic data, the harmonic characteristic vector is generated in combination with the structural parameters. The threshold judgment unit performs statistical detection on the harmonic characteristic vector in a sliding window manner, marking the abnormal channel. The fault location unit performs trend change comparison based on the abnormal position, marks the fault location label, and finally summarizes and constructs the communication data frame, which is uploaded to the data analysis background 400 through the optical fiber communication interface for subsequent analysis and display.

[0041] It should also be noted that the data acquisition component 300 realizes the synchronous acquisition of high-frequency voltage and current signals, harmonic modeling driven by structural parameters, and abnormal judgment and positioning data encapsulation based on environmental perception through the linkage design of analog-to-digital conversion, adaptive filtering and edge processing modules, and constructs an end-side closed-loop processing path from signal input to fault identification and data upload.

[0042] S4: The data analysis backend 400 is in communication with the data acquisition component 300, and is used to receive the uploaded data frames and display the harmonic monitoring information in collaboration with the interactive interface.

[0043] Furthermore, the data analysis background 400 includes a data parsing module and an interactive display module; the data parsing module is used to parse the uploaded data frame fields and generate a structured data set, and the interactive display module is used to graphically display the frequency amplitude diagram, abnormal marking points and abnormal labels, and at the same time provide historical record retrieval, manual marking and abnormal confirmation operation interfaces.

[0044] It should be noted that the data analysis background 400 receives communication data frames, the data parsing module parses the data frames one by one, extracts the field content and performs data cleaning, classification and formatting, and constructs a structured data set corresponding to the time series and the node sequence. The interactive display module receives the structured data set and performs graphical rendering of the interface, displays the correspondence between frequency and amplitude in the frequency amplitude graph, displays the abnormal mark status of each node in the node list area, and displays the mutation point information and fault location results in the abnormal mark area. The display interface supports users to click on the node to view detailed time domain or frequency domain historical records, and can manually correct the abnormal mark status. All interactive behaviors are recorded in log files and written into the main control database for backup.

[0045] It should also be noted that the data analysis backend 400 realizes the field analysis of uploaded data frames and the visual expression of spectrum status through the structural linkage of the data analysis module and the interactive display module, and builds an analysis and display interface system that integrates data synchronization, anomaly tracking and interactive annotation.

[0046] Example 2, reference Figure 3 , as one embodiment of the present invention, provides a harmonic monitoring method for a wall bushing in a flexible DC converter station, comprising:

[0047] S5: A signal acquisition path is constructed through the capacitor voltage divider component 100 and the broadband current sensing component 200, and the voltage and current signals are received through the analog-to-digital conversion module for synchronous sampling and digital processing.

[0048] S6: Based on the adaptive filtering module and the edge processing module, the collected signal is decomposed by wavelet to generate a harmonic feature vector. The parameter statistics are calculated by combining the internal temperature monitoring probe T, and an abnormal mark and positioning request instruction are output.

[0049] S7: Based on the fault location unit, a location identification operation is performed on the abnormality mark, and the harmonic feature vector, the abnormality mark and the location tag are encapsulated into a communication data frame, and uploaded to the data analysis background 400 through the optical fiber communication link.

Claims

1. A harmonic monitoring system for a wall bushing in a flexible DC converter station, characterized in that: include: A capacitor voltage dividing component (100) is connected in series with the main capacitor (C) of the wall bushing for voltage division; A broadband current sensing component (200) is annularly arranged on the outer wall of the bushing between the bushing end screen tap (S) and the capacitive voltage dividing component (100), and is connected to the data acquisition component (300); A data acquisition component (300) is connected to the capacitor voltage divider component (100) and the broadband current sensing component (200), performs synchronous sampling, filtering, wavelet transformation, harmonic modeling and feature extraction, and uploads the results to a data analysis backend (400); The data analysis backend (400) is connected to the data acquisition component (300) for receiving uploaded data frames and displaying harmonic monitoring information in collaboration with the interactive interface; The data acquisition component (300) includes an analog-to-digital conversion module, an adaptive filtering module, and an edge processing module; The edge processing module includes wavelet analysis and harmonic structure modeling unit, threshold judgment unit, and fault location unit; The wavelet analysis and harmonic structure modeling unit includes performing multi-scale wavelet decomposition on the collected signal through wavelet analysis to extract frequency characteristic data of different frequency bands; establishing a casing harmonic coupling model based on the casing's geometric dimensions and material dielectric constant, and mapping the frequency characteristic data to form a harmonic characteristic vector; The threshold judgment unit includes receiving harmonic feature vectors, obtaining environmental parameter information based on the internal temperature monitoring probe (T), performing statistical calculations based on a sliding window, building an adaptive threshold model, and outputting an abnormality mark and a positioning request instruction; The fault location unit includes: the fault location unit is connected to the internal communication of the edge processing module, receives each channel abnormality mark and positioning request instruction, and generates a positioning tag through space mapping and change trend comparison.

2. The harmonic monitoring system for a wall bushing in a flexible DC converter station according to claim 1, characterized in that: The capacitive voltage dividing component (100) comprises: It consists of a capacitive voltage divider (C_div) and a wall bushing main capacitor (C) in series, installed between the end screen and the grounding structure through an insulating support, and connected to the signal transmission path through an isolator (B) for electrical isolation sampling.

3. The harmonic monitoring system for the wall bushing of a flexible DC converter station according to claim 2, characterized in that: The broadband current sensing component (200) comprises: A plurality of broadband current sensors (I) are arranged equidistantly around the bushing conductor, with a response bandwidth covering 1 kHz to 10 MHz. Each sensor is respectively connected to a corresponding acquisition channel of the data acquisition component (300) to receive a unified synchronous control signal.

4. The harmonic monitoring system for a wall bushing in a flexible DC converter station according to claim 3, characterized in that: The data acquisition component (300) includes: Analog-to-digital conversion module, adaptive filtering module and edge processing module; The analog-to-digital conversion module includes receiving control signals transmitted by the capacitor voltage dividing component (100) and the broadband current sensing component (200) and converting them digitally into acquisition signals; The adaptive filtering module includes real-time denoising of the collected signal through an adaptive filtering algorithm.

5. The harmonic monitoring system for the wall bushing of a flexible DC converter station according to claim 4, characterized in that: The edge processing module also includes: The harmonic feature vector, anomaly mark and positioning label of each node are packaged into a communication data frame, the data frame fields include sampling timestamp, frequency amplitude, anomaly mark point, node threshold status, and uploaded to the data analysis background (400) through the optical fiber communication link.

6. The harmonic monitoring system for the wall bushing of a flexible DC converter station according to claim 5, characterized in that: The data analysis backend (400) includes: Data analysis module and interactive display module; The data parsing module is used to parse the uploaded data frame fields and generate structured data sets; The interactive display module is used to graphically display frequency amplitude diagrams, abnormal marking points and abnormal labels, and also provides historical record retrieval, manual marking and abnormal confirmation operation interfaces.

7. A method for monitoring harmonics in a wall bushing of a flexible DC converter station, using the harmonic monitoring system for a wall bushing of a flexible DC converter station according to any one of claims 1 to 6, characterized in that: include A signal acquisition path is constructed through a capacitor voltage dividing component (100) and a broadband current sensing component (200), and voltage and current signals are received through an analog-to-digital conversion module for synchronous sampling and digital processing; Based on the adaptive filtering module and edge processing module, the collected signal is decomposed by wavelet to generate harmonic feature vectors. The internal temperature monitoring probe (T) is combined to obtain parameter statistics and output abnormality marks and positioning request instructions. Based on the fault location unit, a location identification operation is performed on the abnormality mark, and the harmonic feature vector, the abnormality mark and the location tag are encapsulated into a communication data frame, which is uploaded to the data analysis background (400) through the optical fiber communication link.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the harmonic monitoring method for the wall bushing of the flexible DC converter station described in claim 7 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the harmonic monitoring method for the wall bushing of a flexible DC converter station described in claim 7 are implemented.

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