Methods, devices, equipment and dielectrics for assessing the risk of DC near-zone resonance in converter stations

Abstract

This invention discloses a method for assessing the risk of DC near-field resonance in converter stations, relating to the field of converter station technology. It addresses the limitation of existing methods for assessing system resonance risk. The method includes the following steps: modeling equivalent harmonics in the AC power grid, AC filter, and synchronous condenser of the converter station; constructing analysis indicators based on the severity of system harmonic resonance; and assessing the risk of high-voltage DC near-field resonance based on the modeling results and the analysis indicators. This invention also discloses a device, electronic equipment, and computer storage medium for assessing the risk of DC near-field resonance in converter stations. This invention obtains the risk assessment results of high-voltage DC near-field resonance by modeling equivalent harmonics in the AC power grid, AC filter, and synchronous condenser of the converter station.

Description

Technical Field

[0001] This invention relates to the field of converter station technology, and more particularly to a method, apparatus, equipment, and medium for assessing the risk of DC near-zone resonance in converter stations. Background Technology

[0002] my country's energy resources are mostly distributed in the northwest, while energy demand is concentrated in the east and central regions. Due to various constraints, large-scale power plant construction in the east and central regions is limited. Therefore, to optimize the allocation of energy resources between regions, energy needs to be transported from the northwest to the central and eastern regions. This energy transportation places enormous pressure on traditional transmission networks. Against this backdrop, high-voltage direct current (HVDC) transmission is increasingly being used due to its advantages of long-distance transmission and high-capacity transmission. Furthermore, to improve the reactive power support capacity of converter stations and meet other requirements, AC filters and synchronous condensers are also widely used in HVDC near-field applications.

[0003] However, in recent years, many converter stations across the country have experienced excessive harmonics after putting AC filters into operation. Traditional DC near-field harmonic models and resonance analysis methods for converter stations have limited accuracy, and there is an urgent need to analyze the impact of AC filters and synchronous condensers on system resonance. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, one of the objectives of this invention is to provide a method for assessing the risk of DC near-zone resonance in converter stations. This method involves modeling the AC power grid, AC filter, and synchronous condenser of the converter station, analyzing harmonic resonance, and then assessing the resonance risk.

[0005] One of the objectives of this invention is achieved through the following technical solution:

[0006] A method for assessing the risk of DC near-field resonance in a converter station includes the following steps:

[0007] Equivalent harmonic modeling is performed on the AC power grid, AC filter, and synchronous condenser of the converter station;

[0008] Analytical indicators are constructed based on the severity of system harmonic resonance.

[0009] Based on the modeling results and the analysis indicators, a risk assessment of near-field resonance in high-voltage direct current was conducted.

[0010] Furthermore, the modeled system includes: the equivalent harmonic model of the AC power grid, the equivalent harmonic model of the AC filter, and the equivalent harmonic model of the synchronous condenser.

[0011] Furthermore, the equivalent harmonic model of the AC-side power grid satisfies:

[0012]

[0013] Where h is the harmonic order, Z s.h For the equivalent harmonic model of the AC power grid at the h-th order, U r The nominal voltage on the high-voltage side of the system, Q r This refers to the system's short-circuit capacity;

[0014] The dual-tuned filter of the AC power grid includes two equivalent single-tuned filter parameters that satisfy:

[0015]

[0016]

[0017]

[0018]

[0019] Among them, C a L a C b L b These are the capacitance and inductance values ​​of the two equivalent single-tuned filters of the dual-tuned filter, respectively. N1 and N2 are the tuning times of the two single-tuned filters, respectively. Q1 and Q2 are the reactive power design capacity of the two single-tuned filters, respectively. ω1 is the system fundamental frequency angular velocity.

[0020] Based on the equivalent single-tuned filter parameters, the equivalent parameters of the dual-tuned filter of the AC power grid satisfy:

[0021] C1 = C a +C b

[0022]

[0023]

[0024]

[0025] Wherein, C1 and L1 are the main capacitor and main inductor of the dual-tuned filter, respectively, and C2 and L2 are the auxiliary capacitor and auxiliary inductor of the dual-tuned filter, respectively.

[0026] Furthermore, the equivalent harmonic model of the AC filter satisfies:

[0027]

[0028] Among them, Z f.h For the h-th order equivalent harmonic model of a double-tuned filter, ω h Let be the angular velocity of the system under the h-th harmonic.

[0029] Furthermore, the equivalent harmonic model of the synchronous modulator satisfies:

[0030]

[0031]

[0032] Z c.h =Z G.h +Z T.h ,

[0033] Among them, Z G.h Z T.h Z c.h X1 represents the equivalent harmonic model of the synchronous condenser, the step-up transformer, and the synchronous condenser branch at the h-th order, respectively. X2 represents the negative sequence impedance per unit value of the synchronous condenser, and Q represents the equivalent harmonic model of the synchronous condenser branch at the h-th order. G For the rated capacity of the synchronous condenser, V S denoted as the transformer short-circuit voltage, and l is the capacity margin ratio of the step-up transformer.

[0034] Furthermore, the analysis indicators include the h-th harmonic voltage and harmonic amplification factor after the filter is connected to the PCC point, and the h-th harmonic voltage V after the filter is connected to the PCC point. post.h satisfy:

[0035]

[0036] Among them, I b.h Z represents the equivalent harmonic current of the AC power grid at the h-th order. s.h For the equivalent harmonic model of the AC power grid at the h-th order, Z C.h For the equivalent harmonic model of the synchronous modulator branch at the h-th order, Z f.h The equivalent harmonic model of the h-th order of the dual-tuned filter;

[0037] The harmonic amplification factor (HAR) satisfies:

[0038]

[0039] Among them, V pre.h The h-th harmonic voltage before the filter is connected to the PCC point is calculated to satisfy:

[0040]

[0041] Furthermore, based on the modeling results and the analytical indicators, a risk assessment of near-field resonance in high-voltage direct current (HVDC) is conducted, including:

[0042] Based on the modeling results, calculate the equivalent harmonic impedances of the AC power grid, filters, and synchronous condensers.

[0043] Calculate the amplification factor of each harmonic based on the equivalent harmonic impedance calculation results;

[0044] Based on the system harmonic voltage, risk marking is performed on the AC side grid short-circuit capacity, AC filter commissioning capacity, and synchronous condenser rated capacity that exceed the single distortion rate after each harmonic is amplified by the harmonic amplification factor.

[0045] Based on the risk markers, a harmonic resonance risk assessment diagram for each harmonic is generated.

[0046] The second objective of this invention is to provide a DC near-field resonance risk assessment device for converter stations, which obtains resonance risk assessment results by performing equivalent harmonic modeling on the converter station.

[0047] The second objective of this invention is achieved by the following technical solution:

[0048] A converter station DC near-field resonance risk assessment device, comprising:

[0049] The model building module is used to perform equivalent harmonic modeling of the AC power grid, AC filter and synchronous condenser of the converter station;

[0050] The index construction module is used to construct analytical indicators based on the severity of system harmonic resonance.

[0051] The risk assessment module is used to assess the risk of high voltage DC near-field resonance based on the modeling results and the analysis indicators.

[0052] A third objective of this invention is to provide an electronic device for performing one of the objectives of the invention, comprising a processor, a storage medium, and a computer program, wherein the computer program is stored in the storage medium, and when the computer program is executed by the processor, it implements the above-mentioned method for assessing the DC near-field resonance risk of a converter station.

[0053] The fourth objective of this invention is to provide a computer-readable storage medium storing one of the objectives of the invention, wherein a computer program is stored thereon, and when the computer program is executed by a processor, it implements the above-mentioned method for assessing the risk of DC near-field resonance in converter stations.

[0054] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0055] This invention evaluates and models the equivalent harmonics of the AC power grid, AC filters, and synchronous condensers in the converter station, and establishes analytical indicators to assess whether the harmonics meet national standards. Furthermore, it analyzes the risk of system harmonic resonance based on the real-time short-circuit capacity, the operational capacity of the synchronous condensers, and the operational capacity of the filters. Attached Figure Description

[0056] Figure 1 This is a flowchart of the DC near-field resonance risk assessment method for converter stations in Implementation Example 1;

[0057] Figure 2 This is a flowchart of the risk assessment method in Implementation Example 1;

[0058] Figure 3 This is a schematic diagram of the harmonic resonance risk assessment in Implementation Example 1;

[0059] Figure 4 This is a structural block diagram of the converter station DC near-field resonance risk assessment device in Embodiment 2;

[0060] Figure 5 This is a structural block diagram of the electronic device in Embodiment 3. Detailed Implementation

[0061] The present invention will now be described in more detail with reference to the accompanying drawings. It should be noted that the following description of the present invention with reference to the accompanying drawings is merely illustrative and not restrictive. Various embodiments can be combined with each other to form other embodiments not shown in the following description.

[0062] Example 1

[0063] Example 1 provides a method for assessing the risk of DC near-field resonance in a converter station. The method aims to assess the risk of high-voltage DC near-field resonance by performing equivalent harmonic modeling on the AC power grid, AC filter, and synchronous condenser of the converter station.

[0064] Based on the limitations of existing research, this embodiment provides a method for analyzing the resonance risk in AC filters and synchronous condensers of converter stations under different configuration capacities. On this basis, it provides a rapid assessment technology for DC near-field resonance risk of converter stations, which can provide a reference for the filter capacity configuration scheme of converter stations.

[0065] Please refer to Figure 1 As shown, a method for assessing the risk of DC near-field resonance in a converter station includes the following steps:

[0066] S1. Perform equivalent harmonic modeling on the AC side power grid, AC filter and synchronous condenser of the converter station;

[0067] In S1, the model specifically includes the equivalent harmonic model of the AC power grid, the equivalent harmonic model of the AC filter, and the equivalent harmonic model of the synchronous condenser.

[0068] The equivalent harmonic model of the AC power grid satisfies:

[0069]

[0070] Where h is the harmonic order, Zs.h For the equivalent harmonic model of the AC power grid at the h-th order, U r The nominal voltage on the high-voltage side of the system, Q r This refers to the system's short-circuit capacity;

[0071] Converter station AC filters typically employ dual-tuned filters. To derive the equivalent harmonic model of a dual-tuned filter, it is necessary to first determine the parameters of the two equivalent single-tuned filters, satisfying the following conditions:

[0072]

[0073]

[0074]

[0075]

[0076] Among them, C a L a C b L b These are the capacitance and inductance values ​​of the two equivalent single-tuned filters of the dual-tuned filter, respectively. N1 and N2 are the tuning times of the two single-tuned filters, respectively. Q1 and Q2 are the reactive power design capacity of the two single-tuned filters, respectively. ω1 is the system fundamental frequency angular velocity.

[0077] Based on the equivalent single-tuned filter parameters, the equivalent parameters of the dual-tuned filter of the AC power grid satisfy:

[0078] C1 = C a +C b

[0079]

[0080]

[0081]

[0082] Wherein, C1 and L1 are the main capacitor and main inductor of the dual-tuned filter, respectively, and C2 and L2 are the auxiliary capacitor and auxiliary inductor of the dual-tuned filter, respectively.

[0083] The equivalent harmonic model of an AC filter satisfies:

[0084]

[0085] Among them, Z f.h For the h-th order equivalent harmonic model of a double-tuned filter, ω h Let be the angular velocity of the system under the h-th harmonic.

[0086] The equivalent harmonic model of a synchronous modulator satisfies:

[0087]

[0088]

[0089] Z c.h =Z G.h +Z T.h ,

[0090] Among them, Z G.h Z T.h Z c.h X1 represents the equivalent harmonic model of the synchronous condenser, the step-up transformer, and the synchronous condenser branch at the h-th order, respectively. X2 represents the negative sequence impedance per unit value of the synchronous condenser, and Q represents the equivalent harmonic model of the synchronous condenser branch at the h-th order. G For the rated capacity of the synchronous condenser, V S denoted as the transformer short-circuit voltage, and l is the capacity margin ratio of the step-up transformer.

[0091] S2. Construct analytical indicators based on the severity of system harmonic resonance;

[0092] In actual operation, AC filter banks often undergo a series of switching operations to meet the needs of system filtering and reactive power compensation. However, since the equivalent impedance of the AC power grid and synchronous condenser is inductive, while the equivalent impedance of the AC filter is capacitive at the tuning point, when the two are equal at a certain frequency, a severe harmonic amplification phenomenon occurs, which is called harmonic resonance. The indicators for analyzing the severity of harmonic resonance include the h-th harmonic voltage and the harmonic amplification factor after the filter is connected to the PCC point. The h-th harmonic voltage V after the filter is connected to the PCC point... post.h satisfy:

[0093]

[0094] Among them, I b.h Z represents the equivalent harmonic current of the AC power grid at the h-th order. s.h For the equivalent harmonic model of the AC power grid at the h-th order, Z C.H For the equivalent harmonic model of the synchronous modulator branch at the Hth order, Z f.H The equivalent harmonic model of the Hth order of a dual-tuned filter;

[0095] The harmonic amplification factor (HAR) can be quantified by the impedance ratio before and after the AC filter is put into operation at the PCC point. The HAR satisfies the following:

[0096]

[0097] Although harmonic resonance is difficult to avoid, it is constrained by the background harmonic content and the harmonic amplification factor. When the background harmonics are amplified by resonance and exceed the harmonic standard limit, the system's filter is at risk of resonance. Wherein, V pre.g The h-th harmonic voltage before the filter is connected to the PCC point is calculated to satisfy:

[0098]

[0099] S3. Based on the modeling results and the analysis indicators, conduct a risk assessment of near-field resonance of high-voltage DC.

[0100] Currently, the commonly used short-circuit capacities of the AC side power grid in 330kV converter stations are 2296Mvar and 5000Mvar. Therefore, the system short-circuit capacity within this range is usually considered. Since converter stations often simultaneously connect or disconnect a set of characteristic filters, and considering the commonly used filter bank configuration schemes for converter stations, this embodiment assumes that the AC filter banks in the converter station all use 11 / 13 and 24 / 36th order double-tuned filters, and that the reactive power design capacity at each tuning point is equal. Simultaneously, based on the typical negative sequence parameter of the synchronous condenser (0.255pu) from the EMTDC / PSCAD platform, the short-circuit voltage of the step-up transformer is 11.5%, and the step-up transformer margin capacity ratio is 1.2, etc., this embodiment also considers information such as...

[0101] Based on the calculations and analyses in S1 and S2, S3 requires analyzing the interaction between AC filters of different capacities, synchronous condensers, and the background harmonic impedance on the AC side. Please refer to... Figure 2 As shown, S3 specifically includes:

[0102] S31. Based on the modeling results, calculate the equivalent harmonic impedance of the AC power grid, filter, and synchronous condenser.

[0103] S32. Calculate the amplification factor of each harmonic based on the equivalent harmonic impedance calculation results;

[0104] S33. Based on the system harmonic voltage, risk marking is performed on the AC side grid short-circuit capacity, AC filter commissioning capacity, and synchronous condenser rated capacity that exceed the single distortion rate after each harmonic is amplified by the harmonic amplification factor.

[0105] Suppose that the 5th harmonic voltage of a converter station without an operational AC filter is 1.0%. Since the public power grid harmonic standard requires a single harmonic distortion rate of 1.6% for networks above 110kV, the harmonic amplification factor exceeds 1.6 under the 5th harmonic. At this time, the short-circuit capacity of the AC power grid, the operational capacity of the AC filter, and the rated capacity of the synchronous condenser are at risk of resonance.

[0106] S34. Generate a harmonic resonance risk assessment diagram for each harmonic based on the risk markers.

[0107] Please refer to Figure 3 The risk assessment diagram for the fifth harmonic resonance of the converter station shown illustrates that only the operation of a specific AC filter capacity will cause harmonic amplification in the system. Based on this risk assessment diagram, users typically mitigate potential resonance points by adjusting the reactive power capacity of the AC filter bank to avoid this risk.

[0108] In summary, based on the resonance risk assessment diagram, users can quickly identify the resonance risk in the DC near-field of the converter station according to the system's short-circuit capacity, filter operating capacity, and synchronous condenser operating capacity.

[0109] Example 2

[0110] Example 2 discloses a device corresponding to the converter station DC near-field resonance risk assessment method in the above embodiments. It is a virtual device structure of the above embodiments. Please refer to... Figure 4 As shown, it includes:

[0111] Model building module 210 is used to perform equivalent harmonic modeling of the AC power grid, AC filter and synchronous condenser of the converter station;

[0112] The index construction module 220 is used to construct analytical indices based on the severity of system harmonic resonance.

[0113] Risk assessment module 230 is used to assess the risk of high voltage DC near-field resonance based on the modeling results and the analysis indicators.

[0114] The modeled components include: the equivalent harmonic model of the AC power grid, the equivalent harmonic model of the AC filter, and the equivalent harmonic model of the synchronous condenser.

[0115] The analysis indicators include the h-th harmonic voltage and harmonic amplification factor after the filter is connected to the PCC point. The h-th harmonic voltage Vpost.h after the filter is connected to the PCC point satisfies:

[0116]

[0117] Where Ib.h is the equivalent harmonic current of the AC power grid at the h-th order, Z s.h For the equivalent harmonic model of the AC power grid at the h-th order, Z C.h For the equivalent harmonic model of the synchronous modulator branch at the h-th order, Z f.h The equivalent harmonic model of the h-th order of the dual-tuned filter;

[0118] The harmonic amplification factor (HAR) satisfies:

[0119]

[0120] Where Vpre.h is the h-th harmonic voltage before the filter is connected to the PCC point, and its calculation satisfies:

[0121]

[0122] Based on the modeling results and analysis indicators, a risk assessment of near-field resonance in high-voltage direct current (HVDC) is conducted, including:

[0123] Based on the modeling results, calculate the equivalent harmonic impedances of the AC power grid, filters, and synchronous condensers.

[0124] Calculate the amplification factor of each harmonic based on the equivalent harmonic impedance calculation results;

[0125] Based on the system harmonic voltage, risk marking is performed on the AC side grid short-circuit capacity, AC filter commissioning capacity, and synchronous condenser rated capacity that exceed the single distortion rate after each harmonic is amplified by the harmonic amplification factor.

[0126] Based on the risk markers, a harmonic resonance risk assessment diagram for each harmonic is generated.

[0127] Example 3

[0128] Figure 5 This is a schematic diagram of the structure of an electronic device provided in Embodiment 3 of the present invention, as shown below. Figure 5 As shown, the electronic device includes a processor 310, a memory 320, an input device 330, and an output device 340; the number of processors 310 in the computer device can be one or more. Figure 5 Taking a processor 310 as an example; the processor 310, memory 320, input device 330, and output device 340 in the electronic device can be connected via a bus or other means. Figure 5 Taking the example of a connection between China and Israel via a bus.

[0129] The memory 320, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to the converter station DC near-field resonance risk assessment method in this embodiment of the invention. The processor 310 executes various functional applications and data processing of the electronic device by running the software programs, instructions, and modules stored in the memory 320, thereby implementing the converter station DC near-field resonance risk assessment method of the above embodiment.

[0130] The memory 320 may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a given function; the data storage area may store data created based on terminal usage. Furthermore, the memory 320 may include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some instances, the memory 320 may further include memory remotely located relative to the processor 310, which can be connected to the electronic device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0131] Input device 330 can be used to receive input user identity information, power grid data, etc. Output device 340 may include display devices such as a display screen.

[0132] Example 4

[0133] Embodiment 4 of the present invention also provides a storage medium containing computer-executable instructions, which can be used by a computer to execute a method for assessing the risk of DC near-field resonance in a converter station, the method comprising:

[0134] Equivalent harmonic modeling is performed on the AC power grid, AC filter, and synchronous condenser of the converter station;

[0135] Analytical indicators are constructed based on the severity of system harmonic resonance.

[0136] Based on the modeling results and the analysis indicators, a risk assessment of near-field resonance in high-voltage direct current was conducted.

[0137] Of course, the computer-executable instructions provided in the embodiments of the present invention are not limited to the method operations described above, but can also perform related operations in the converter station DC near-field resonance risk assessment method provided in any embodiment of the present invention.

[0138] Based on the above description of the implementation methods, those skilled in the art can clearly understand that the present invention can be implemented using software and necessary general-purpose hardware, and of course, it can also be implemented using hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause an electronic device (which may be a mobile phone, personal computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0139] It is worth noting that in the above embodiments of the method and device for assessing the risk of DC near-zone resonance in converter stations, the various units and modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of each functional unit are only for easy differentiation and are not used to limit the scope of protection of the present invention.

[0140] For those skilled in the art, various other corresponding changes and modifications can be made based on the technical solutions and concepts described above, and all such changes and modifications should fall within the protection scope of the claims of this invention.

Claims

1. A method for evaluating resonance risk in a DC proximity of a converter station, characterized in that, Includes the following steps: Equivalent harmonic modeling is performed on the AC side power grid of the converter station, the dual-tuned filter, and the synchronous condenser; wherein, the equivalent harmonic model of the synchronous condenser satisfies: ， in, , , These are the synchronous condenser, step-up transformer, and synchronous condenser branch, respectively. Equivalent harmonic model of the first order For harmonic order, This represents the per-unit value of the negative sequence impedance of the synchronous modulator. To synchronize the camera's rated capacity, This is the transformer short-circuit voltage. This refers to the capacity margin ratio of the step-up transformer. This refers to the nominal voltage on the high-voltage side of the system. An analysis index is constructed based on the severity of system harmonic resonance; the analysis index includes the parameters after the filter is connected to the PCC point. The second harmonic voltage and harmonic amplification factor, after the connection point to the PCC Subharmonic voltage satisfy: in, For the AC side power grid The equivalent harmonic current of the first order, For the AC side power grid Equivalent harmonic model of the first order For a dual-tuned filter The equivalent harmonic model of the first order; the harmonic amplification coefficient satisfies: wherein for the filter access point before the PCC point sub-harmonic voltage, the calculation of which satisfies: ； Based on the modeling results and the aforementioned analysis indicators, a risk assessment of near-field resonance in high-voltage direct current (HVDC) is conducted, including: Based on the modeling results, calculate the equivalent harmonic impedance of the AC power grid, filter, and synchronous condenser; Calculate the amplification factor of each harmonic based on the equivalent harmonic impedance calculation results; Based on the system harmonic voltage, risk marking is performed on the AC side grid short-circuit capacity, dual-tuned filter commissioning capacity, and synchronous condenser rated capacity corresponding to each harmonic that exceeds the single distortion rate after being amplified by the harmonic amplification factor. Based on the risk markers, a harmonic resonance risk assessment diagram for each harmonic is generated.

2. The method for assessing the risk of DC near-zone resonance in a converter station as described in claim 1, characterized in that, The equivalent harmonic model of the AC power grid satisfies: ， in, For harmonic order, For the AC side power grid Equivalent harmonic model of the first order The nominal voltage of the high-voltage side of the system, This refers to the system's short-circuit capacity. The dual-tuned filter on the AC side of the power grid consists of two equivalent single-tuned filter parameters that satisfy: ， in, , , , These are the capacitance and inductance values ​​of the two equivalent single-tuned filters of the dual-tuned filter. , These represent the tuning times of the two single-tuned filters. and These represent the reactive power design capacity of two single-tuned filters. The system's fundamental frequency angular velocity; Based on the equivalent single-tuned filter parameters, the equivalent parameters of the dual-tuned filter of the AC power grid satisfy: ， in, , These are the main capacitor and main inductor of the dual-tuned filter. , These are the auxiliary capacitor and auxiliary inductor of the dual-tuned filter.

3. The method of claim 1, wherein the method further comprises: The equivalent harmonic model of the dual-tuned filter satisfies: ， wherein, is the angular velocity of the system at the first harmonic, is the angular velocity of the system at the second harmonic.

4. A device for evaluating resonance risk in a DC proximity of a converter station, characterized in that It includes: The model building module is used to perform equivalent harmonic modeling of the AC-side power grid, dual-tuned filter, and synchronous condenser of the converter station; wherein, the equivalent harmonic model of the synchronous condenser satisfies: ， in, , , These are the synchronous condenser, step-up transformer, and synchronous condenser branch, respectively. Equivalent harmonic model of the first order For harmonic order, This represents the per-unit value of the negative sequence impedance of the synchronous modulator. To synchronize the camera's rated capacity, This is the transformer short-circuit voltage. This refers to the capacity margin ratio of the step-up transformer. This refers to the nominal voltage on the high-voltage side of the system. The index construction module is configured to construct an analysis index according to the system harmonic resonance severity; the analysis index includes the filter access PCC point after sub-harmonic voltage and harmonic amplification coefficient, the filter access PCC point after sub-harmonic voltage satisfies: in, For the AC side power grid The equivalent harmonic current of the first order, For the AC side power grid Equivalent harmonic model of the first order For a dual-tuned filter The equivalent harmonic model of the first order; the harmonic amplification factor satisfies: wherein, for the filter to access the PCC point before sub-harmonic voltage, the calculation of which satisfies: ； The risk assessment module is used to assess the risk of near-field resonance in high-voltage direct current based on the modeling results and the aforementioned analysis indicators, including: Based on the modeling results, calculate the equivalent harmonic impedance of the AC power grid, filter, and synchronous condenser; Calculate the amplification factor of each harmonic based on the equivalent harmonic impedance calculation results; Based on the system harmonic voltage, risk marking is performed on the AC side grid short-circuit capacity, dual-tuned filter commissioning capacity, and synchronous condenser rated capacity corresponding to each harmonic that exceeds the single distortion rate after being amplified by the harmonic amplification factor. Based on the risk markers, a harmonic resonance risk assessment diagram for each harmonic is generated.

5. An electronic device comprising a processor, a storage medium, and a computer program stored in the storage medium, characterized in that, When the computer program is executed by the processor, it implements the DC near-field resonance risk assessment method for converter stations as described in any one of claims 1 to 3.

6. A computer-readable storage medium having stored thereon a computer program, characterized in that, When the computer program is executed by the processor, it implements the DC near-field resonance risk assessment method for converter stations as described in any one of claims 1 to 3.

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