Series compensation platform secondary equipment shielding effect analysis method and system under strong electromagnetic interference

Abstract

The invention discloses a series compensation platform secondary equipment shielding effect analysis method and system under strong electromagnetic interference, and the method comprises the steps: carrying out the multi-conductor modeling of a series compensation platform and a bus, and carrying out the finite element modeling of the primary equipment of the series compensation platform, thereby building a rapid transient overvoltage simulation model of the primary equipment of the series compensation platform; performing simulation to obtain rapid transient overvoltage between the low-voltage bus and the high-potential platform at the position of the secondary equipment measurement box under the set overvoltage condition; finite element modeling is carried out on the secondary equipment, a rapid transient overvoltage signal between a low-voltage bus and a high-potential platform is applied to the modeling, electric field distribution under the set overvoltage condition is obtained through simulation, and the shielding effectiveness of a measurement box of the secondary equipment under different frequencies is calculated; changing the materials of the secondary equipment to analyze the electromagnetic shielding effectiveness of different materials under the set overvoltage condition; according to the invention, effective anti-electromagnetic interference measures can be provided effectively, and the anti-interference performance of the secondary equipment of the high-voltage series compensation platform is improved.

Description

Technical Field

[0001] The present invention relates to the field of electromagnetic shielding effect analysis, and in particular to a method and system for analyzing the shielding effect of secondary equipment of a series compensation platform under strong electromagnetic interference. Background Art

[0002] With the development of modern power systems, the capacity and transmission distances of transmission lines continue to increase, and the problems of high voltage, high current, and complex electromagnetic environments have become increasingly prominent. In particular, during power system operation, rapid transient overvoltages may be generated due to switching operations, fault clearing, and other factors. These overvoltages not only affect primary equipment but also pose a serious threat to the normal operation of secondary equipment.

[0003] As a crucial component of power systems, series compensation platforms improve transmission capacity and stability by introducing series compensation into transmission lines. However, in fast transient overvoltage environments, the secondary components of the series compensation platform (such as protection devices, measuring instruments, and control systems) are highly susceptible to electromagnetic interference, which can affect their functionality and even cause equipment failure. Therefore, effectively shielding and protecting the secondary components of the series compensation platform to ensure stable operation in complex electromagnetic environments has become a pressing technical challenge.

[0004] Currently, several studies and technologies have been applied to shielding and protecting equipment against rapid transient overvoltages in power systems. However, these technologies still have limitations in terms of electromagnetic shielding effectiveness for secondary equipment on series compensation platforms. Existing shielding technologies often lack systematic analysis and optimization, relying primarily on empirical experience and simple test data, lacking theoretical support and precise simulation verification. This results in unstable shielding effectiveness in different application scenarios, making it impossible to ensure reliable operation of secondary equipment in various complex electromagnetic environments. Summary of the Invention

[0005] In order to solve the deficiencies in the prior art, the present invention provides a method and system for analyzing the shielding effect of secondary equipment of a series compensation platform under strong electromagnetic interference.

[0006] The present invention adopts the following technical solutions.

[0007] The first aspect of the present invention provides a method for analyzing the shielding effect of secondary equipment of a series compensation platform under strong electromagnetic interference, which is characterized by comprising:

[0008] Multi-conductor modeling of the series compensation platform and busbar, and finite element modeling of the primary equipment of the series compensation platform, are performed to establish a fast transient overvoltage simulation model of the primary equipment of the series compensation platform. The simulation obtains the fast transient overvoltage between the low-voltage busbar and the high-potential platform at the location of the secondary equipment measurement box under the set overvoltage condition;

[0009] Conduct finite element modeling of the secondary equipment, apply a fast transient overvoltage signal between the low-voltage busbar and the high-potential platform to the model, simulate the electric field distribution under the set overvoltage condition, and calculate the shielding effectiveness of the secondary equipment's measurement box at different frequencies;

[0010] Change the material of secondary equipment to analyze the electromagnetic shielding effectiveness of different materials under set overvoltage conditions;

[0011] Preferably, a multi-conductor modeling is performed on the series compensation platform, specifically as follows:

[0012] The series compensation platform is segmented along the width and height directions, and the conductor self-resistance, self-inductance, and mutual inductance of each segment with other segments are measured to establish an equivalent circuit after segmentation: the equivalent circuit is composed of each segment of the equivalent circuit in parallel, and each segment of the equivalent circuit is the resistance and inductance of the conductor of each segment in series, the resistance is equal to the measured corresponding conductor self-resistance, and the self-inductance of the inductor and the mutual inductance of the inductance of the equivalent circuit of other segments are equal to the measured corresponding self-inductance and the mutual inductance of the other segments respectively.

[0013] Preferably, multi-conductor modeling is performed on the busbar, specifically:

[0014] The busbars include a high-voltage busbar and a low-voltage busbar. Both busbars are segmented, and the conductor self-resistance, self-inductance, and mutual inductance with other segments of each segment of the high-voltage busbar and the low-voltage busbar are measured to establish equivalent circuits of the segmented high-voltage busbar and the low-voltage busbar: the equivalent circuits of the high-voltage busbar and the low-voltage busbar are each composed of a corresponding equivalent circuit of each segment in series, and each equivalent circuit of each segment is a resistance and inductance of the conductor of each segment in series, the resistance is equal to the measured corresponding conductor self-resistance, the self-inductance of the inductance and the mutual inductance of the inductance of the equivalent circuit of other segments are equal to the measured corresponding self-inductance and the mutual inductance with the other segments, wherein the mutual inductance with other segments includes the mutual inductance of other segments on the same busbar and the mutual inductance of the same segment on different buses.

[0015] Preferably, finite element modeling is performed on the primary equipment, specifically:

[0016] Modeling is performed based on the topological structure of the primary equipment, which includes metal oxide voltage limiters (MOVs), spark gaps, series disconnectors, series capacitor banks, and damping circuits.

[0017] The metal oxide voltage limiter (MOV) is equivalent to a voltage-controlled current source; the spark gap is equivalent to a structure in which a capacitor and a time-varying resistor are connected in parallel; the series disconnector is equivalent to a structure in which a time-varying resistor, a lossless transmission line, and a capacitance to ground are connected in parallel; the series capacitor bank and the damping circuit are represented by lumped elements in the ATP-EMTP software.

[0018] Preferably, the set overvoltage condition is spark gap triggering and isolating switch operation.

[0019] Preferably, finite element modeling is performed on the secondary equipment, specifically:

[0020] Modeling is performed based on the topological structure of the secondary equipment. The secondary equipment consists of a measurement box, PCB board, steel structure, and low-voltage busbar. During modeling and simulation, the material and dimensions of the measurement box, the depth of the box slot, the material and outer diameter of the low-voltage busbar, the material and dimensions of the PCB board, and the material and dimensions of the steel structure are obtained.

[0021] The three sides of the front of the measuring box are slit to serve as the door of the measuring box; the back of the measuring box is connected to the steel frame; a layer of PCB board is sandwiched inside the measuring box;

[0022] During modeling, the PCB board is replaced by a dielectric board whose length and width are the same as the front plane of the measurement box.

[0023] Preferably, the shielding effectiveness of the measuring box of the secondary device at different frequencies is calculated as follows:

[0024] Model the secondary equipment by applying a fast transient overvoltage signal between the low-voltage busbar and the high-potential platform. Simulate the electric field distribution in the measurement box area and on the PCB surface of the secondary equipment. Calculate the electric field strength at a set point on the PCB with and without the measurement box. The set point on the PCB is where the sensitive component of the PCB is located. Calculate the shielding effectiveness SE of the measurement box at different frequencies according to the formula:

[0025]

[0026] Among them, E0 is the electric field strength at a certain point on the PCB board at the set frequency without the measurement box, and E c The electric field strength at a certain point on the PCB board after adding the measurement box at the set frequency.

[0027] Preferably, the material of the secondary equipment is changed to analyze the electromagnetic shielding effectiveness of different materials under a set overvoltage condition, specifically:

[0028] By changing the material of the measuring box of the secondary equipment, the electromagnetic shielding effectiveness of boxes of different materials under a set overvoltage condition is calculated; by changing the thickness and material of the PCB board, the electromagnetic shielding effectiveness of different dielectric boards under a set overvoltage condition is analyzed.

[0029] Preferably, the changed box material includes copper, No. 10 steel, and the PCB board thickness includes 4, 6, and 8 mm.

[0030] The second aspect of the present invention provides a shielding effectiveness analysis system for secondary equipment of a series compensation platform under strong electromagnetic interference using the method described in the first aspect of the present invention, comprising a primary equipment modeling module, a secondary equipment modeling module, and a shielding effectiveness calculation module at different frequencies, characterized in that:

[0031] Primary equipment modeling module: used to perform multi-conductor modeling of the series compensation platform and busbar, and finite element modeling of the primary equipment of the series compensation platform, so as to establish a fast transient overvoltage simulation model of the primary equipment of the series compensation platform. The simulation obtains the fast transient overvoltage Uo between the low-voltage busbar and the high-potential platform at the location of the secondary equipment measurement box under the set overvoltage condition;

[0032] Secondary equipment modeling module: used for finite element modeling of secondary equipment;

[0033] Shielding effectiveness calculation module at different frequencies: used to model the secondary equipment and apply a fast transient overvoltage signal between the low-voltage bus and the high-potential platform. This module simulates the electric field distribution under the set overvoltage condition and calculates the shielding effectiveness of the secondary equipment's measuring box at different frequencies.

[0034] Shielding effectiveness calculation module under different materials: used to change the material of secondary equipment to analyze the electromagnetic shielding effectiveness of different materials under set overvoltage conditions.

[0035] The beneficial effects of the present invention are as follows: (1) in the electromagnetic transient process, a multi-conductor system consisting of a series compensation platform and a busbar is considered to simulate and calculate the fast transient overvoltage signals generated between the low-voltage busbar and the platform at different positions;

[0036] (2) When analyzing the electromagnetic shielding effectiveness of the secondary equipment measurement box, the influence of electromagnetic interference conduction coupling to the secondary system was mainly considered, and the simulation was a strong power frequency electromagnetic field. This patent simulates and analyzes the electromagnetic shielding effectiveness of the secondary equipment under high-frequency electromagnetic fields based on actual working conditions;

[0037] (3) Taking the overvoltage signal at the location of the secondary measurement box obtained by simulation as the excitation, the electromagnetic field distribution and shielding effectiveness of the secondary equipment measurement box are analyzed through finite element simulation, which can effectively propose effective anti-electromagnetic interference measures and improve the anti-interference performance of the secondary equipment of the high-voltage series compensation platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural diagram of the series compensation platform;

[0039] Figure 2 This is a schematic diagram of the series compensation platform segmentation;

[0040] Figure 3 This is a schematic diagram of busbar segmentation in the series compensation platform;

[0041] Figure 4 It is the segmented equivalent circuit diagram of the series compensation platform;

[0042] Figure 5 It is the equivalent circuit diagram of busbar segment in series compensation platform;

[0043] Figure 6 This is a schematic diagram of overvoltage measurement points;

[0044] Figure 7 Schematic diagram of finite element modeling for secondary equipment; Figure 8 Detailed description of the invention

[0045] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. The embodiments described in this application are only part of the embodiments of the present invention, not all of them. Based on the spirit of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0046] like Figure 8 As shown, embodiment 1 of the present invention proposes a method for analyzing the shielding effect of secondary equipment of a series compensation platform under strong electromagnetic interference, comprising:

[0047] The structure of the series compensation platform is as follows Figure 1 As shown, multi-conductor modeling is performed on the series compensation platform and busbar, and finite element modeling is performed on the primary equipment of the series compensation platform, so as to establish a fast transient overvoltage simulation model of the primary equipment of the series compensation platform. The fast transient overvoltage between the low-voltage busbar and the high-potential platform at the location of the secondary equipment measurement box under the set overvoltage condition is simulated;

[0048] It should be noted that the analysis of fast transient overvoltage is as follows: Figure 6 As shown, point G is the location of the secondary equipment measurement box, point E is the equipotential connection point between the low-voltage bus and the high-potential platform, and the line connecting point E shows that the low-voltage bus and the high-potential platform share a common potential in the initial state. Since we are concerned about the strong electromagnetic interference to the secondary equipment, we need to analyze the fast transient overvoltage at the location of the secondary equipment measurement box through point G, and we can also analyze it at different set locations. This embodiment is Figure 6 The fast transient overvoltage between the marked points A, B, and C on the low-voltage bus and the high-potential platform is analyzed for additional verification.

[0049] In this embodiment, when the overvoltage condition is GAP triggering, GAP is equivalent to switching from the open circuit to the conducting state, and the spark gap is triggered by the trigger voltage U c =320kV, stable on-resistance r v=0.5Ω, discharge time constant τ =1ns, at this time, electromagnetic transient simulation is carried out, and the fast transient overvoltage between points A, B, C on the low-voltage bus and the high-potential platform is measured, and the fast transient overvoltage simulation between the low-voltage bus and the high-potential platform is completed.

[0050] In this embodiment, when the overvoltage condition is GAP triggering, GAP is equivalent to switching from the open circuit to the conducting state, and the spark gap is triggered by the trigger voltage U c =320kV, stable on-resistance r v =0.5Ω, discharge time constant τ=1ns, at this time, electromagnetic transient simulation is carried out, and the fast transient overvoltage between points A, B, C, G on the low-voltage bus and the high-potential platform is measured, and the fast transient overvoltage simulation between the low-voltage bus and the high-potential platform is completed.

[0051] Conduct finite element modeling of the secondary equipment, apply a fast transient overvoltage signal between the low-voltage busbar and the high-potential platform to the model, simulate the electric field distribution under the set overvoltage condition, and calculate the shielding effectiveness of the secondary equipment's measurement box at different frequencies;

[0052] Change the material of secondary equipment to analyze the electromagnetic shielding effectiveness of different materials under set overvoltage conditions;

[0053] Multi-conductor modeling of the series compensation platform is performed as follows:

[0054] like Figure 2 As shown, the series compensation platform is segmented along the width and height directions, and the conductor self-resistance and self-inductance of each segment, as well as the mutual inductance with other segments, are measured to establish the equivalent circuit after segmentation: Figure 4 As shown, the equivalent circuit is composed of each equivalent circuit in parallel. Each equivalent circuit is the resistance and inductance of the conductor of each section in series, the resistance is equal to the measured self-resistance of the corresponding conductor, and the mutual inductance of the self-inductance of the inductor and the inductance of other sections of the equivalent circuit are equal to the measured corresponding self-inductance and the mutual inductance of the other sections.

[0055] Multi-conductor modeling of the busbar is performed, specifically;

[0056] like Figure 3 As shown, the busbar includes a high-voltage busbar and a low-voltage busbar. Both busbars are segmented, and the conductor self-resistance and self-inductance of each segment of the high-voltage busbar and the low-voltage busbar, as well as the mutual inductance with other segments, are measured to establish an equivalent circuit of the segmented high-voltage busbar and the low-voltage busbar: Figure 5As shown, the equivalent circuits of the high-voltage bus and the low-voltage bus are composed of the corresponding equivalent circuits of each segment in series. Each equivalent circuit is the resistance and inductance of the conductor of each segment in series, the resistance is equal to the measured self-resistance of the corresponding conductor, and the mutual inductance of the self-inductance of the inductance and the inductance of the equivalent circuit of other segments is equal to the measured corresponding self-inductance and the mutual inductance of the other segments, where the mutual inductance with other segments includes the mutual inductance of other segments on the same bus and the mutual inductance of the same segment on different buses.

[0057] Finite element modeling of primary equipment is carried out, specifically:

[0058] Modeling is performed based on the topological structure of the primary equipment, which includes metal oxide voltage limiters (MOVs), spark gaps, series disconnectors, series capacitor banks, and damping circuits.

[0059] The metal oxide voltage limiter (MOV) is equivalent to a voltage-controlled current source; the spark gap is equivalent to a structure in which a capacitor and a time-varying resistor are connected in parallel; the series disconnector is equivalent to a structure in which a time-varying resistor, a lossless transmission line, and a capacitance to ground are connected in parallel; the series capacitor bank and the damping circuit are represented by lumped elements in the ATP-EMTP software.

[0060] The assumed overvoltage conditions are spark gap triggering and disconnect switch operation.

[0061] Finite element modeling of secondary equipment is performed, specifically:

[0062] Modeling is performed based on the topological structure of the secondary equipment. The secondary equipment consists of a measurement box, PCB board, steel structure, and low-voltage busbar. During modeling and simulation, the material and dimensions of the measurement box, the depth of the box slot, the material and outer diameter of the low-voltage busbar, the material and dimensions of the PCB board, and the material and dimensions of the steel structure are obtained.

[0063] like Figure 7 As shown, the three sides of the front of the measuring box are slit to serve as the door of the measuring box; the back of the measuring box is connected to the steel frame; a layer of PCB board is sandwiched inside the measuring box;

[0064] During modeling, the PCB board is replaced by a dielectric board whose length and width are the same as the front plane of the measurement box.

[0065] The shielding effectiveness of the measuring box of the secondary equipment at different frequencies is calculated as follows:

[0066] Model the secondary equipment by applying a fast transient overvoltage signal between the low-voltage busbar and the high-potential platform. Simulate the electric field distribution in the measurement box area and on the PCB surface of the secondary equipment. Calculate the electric field strength at a set point on the PCB with and without the measurement box. The set point on the PCB is where the sensitive component of the PCB is located. Calculate the shielding effectiveness SE of the measurement box at different frequencies according to the formula:

[0067]

[0068] Among them, E0 is the electric field strength at a certain point on the PCB board at the set frequency without the measurement box, and E c The electric field strength at a certain point on the PCB board after adding the measurement box at the set frequency.

[0069] Change the material of the secondary equipment to analyze the electromagnetic shielding effectiveness of different materials under the set overvoltage conditions, specifically:

[0070] By changing the material of the measuring box of the secondary equipment, the electromagnetic shielding effectiveness of boxes of different materials under a set overvoltage condition is calculated; by changing the thickness and material of the PCB board, the electromagnetic shielding effectiveness of different dielectric boards under a set overvoltage condition is analyzed.

[0071] The changed box materials include copper and No. 10 steel, and the PCB board thickness includes 4, 6, and 8mm.

[0072] Embodiment 2 of the present invention provides a system for analyzing shielding effectiveness of secondary equipment of a series compensation platform under strong electromagnetic interference using the method described in embodiment 1 of the present invention, and is characterized by comprising:

[0073] Primary equipment modeling module: used to perform multi-conductor modeling of the series compensation platform and busbar, and finite element modeling of the primary equipment of the series compensation platform, so as to establish a fast transient overvoltage simulation model of the primary equipment of the series compensation platform. The simulation obtains the fast transient overvoltage Uo between the low-voltage busbar and the high-potential platform at the location of the secondary equipment measurement box under the set overvoltage condition;

[0074] Secondary equipment modeling module: used for finite element modeling of secondary equipment;

[0075] Shielding effectiveness calculation module at different frequencies: used to model the secondary equipment and apply a fast transient overvoltage signal between the low-voltage bus and the high-potential platform. This module simulates the electric field distribution under the set overvoltage condition and calculates the shielding effectiveness of the secondary equipment's measuring box at different frequencies.

[0076] Shielding effectiveness calculation module under different materials: used to change the material of secondary equipment to analyze the electromagnetic shielding effectiveness of different materials under set overvoltage conditions.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. Analysis method of shielding effect of secondary equipment of series compensation platform under strong electromagnetic interference, characterized by: include: Multi-conductor modeling of the series compensation platform and busbar, and finite element modeling of the primary equipment of the series compensation platform, are performed to establish a fast transient overvoltage simulation model of the primary equipment of the series compensation platform. The simulation obtains the fast transient overvoltage between the low-voltage busbar and the high-potential platform at the location of the secondary equipment measurement box under the set overvoltage condition; Conduct finite element modeling of the secondary equipment, apply a fast transient overvoltage signal between the low-voltage busbar and the high-potential platform to the model, simulate the electric field distribution under the set overvoltage condition, and calculate the shielding effectiveness of the secondary equipment's measurement box at different frequencies; Change the material of the secondary equipment to analyze the electromagnetic shielding effectiveness of different materials under the set overvoltage conditions.

2. The method for analyzing shielding effect of secondary equipment of a series compensation platform under strong electromagnetic interference according to claim 1 is characterized in that: Multi-conductor modeling of the series compensation platform is performed as follows: The series compensation platform is segmented along the width and height directions, and the conductor self-resistance, self-inductance, and mutual inductance of each segment with other segments are measured to establish an equivalent circuit after segmentation: the equivalent circuit is composed of each segment of the equivalent circuit in parallel, and each segment of the equivalent circuit is the resistance and inductance of the conductor of each segment in series, the resistance is equal to the measured corresponding conductor self-resistance, and the self-inductance of the inductor and the mutual inductance of the inductance of the equivalent circuit of other segments are equal to the measured corresponding self-inductance and the mutual inductance of the other segments respectively.

3. The method for analyzing shielding effect of secondary equipment of a series compensation platform under strong electromagnetic interference according to claim 1 is characterized in that: Multi-conductor modeling of the busbar is performed, specifically; The busbars include a high-voltage busbar and a low-voltage busbar. Both busbars are segmented, and the conductor self-resistance, self-inductance, and mutual inductance with other segments of each segment of the high-voltage busbar and the low-voltage busbar are measured to establish equivalent circuits of the segmented high-voltage busbar and the low-voltage busbar: the equivalent circuits of the high-voltage busbar and the low-voltage busbar are each composed of a corresponding equivalent circuit of each segment in series, and each equivalent circuit of each segment is a resistance and inductance of the conductor of each segment in series, the resistance is equal to the measured corresponding conductor self-resistance, the self-inductance of the inductance and the mutual inductance of the inductance of the equivalent circuit of other segments are equal to the measured corresponding self-inductance and the mutual inductance with the other segments, wherein the mutual inductance with other segments includes the mutual inductance of other segments on the same busbar and the mutual inductance of the same segment on different buses.

4. The method for analyzing shielding effectiveness of secondary equipment on a series compensation platform under strong electromagnetic interference according to claim 1 is characterized in that: Finite element modeling of primary equipment is carried out, specifically: Modeling is performed based on the topological structure of the primary equipment, which includes metal oxide voltage limiters (MOVs), spark gaps, series disconnectors, series capacitor banks, and damping circuits. The metal oxide voltage limiter (MOV) is equivalent to a voltage-controlled current source; the spark gap is equivalent to a structure in which a capacitor and a time-varying resistor are connected in parallel; the series disconnector is equivalent to a structure in which a time-varying resistor, a lossless transmission line, and a capacitance to ground are connected in parallel; the series capacitor bank and the damping circuit are represented by lumped elements in the ATP-EMTP software.

5. The method for analyzing shielding effect of secondary equipment of a series compensation platform under strong electromagnetic interference according to claim 1 is characterized in that: The assumed overvoltage conditions are spark gap triggering and disconnect switch operation.

6. The method for analyzing shielding effect of secondary equipment of a series compensation platform under strong electromagnetic interference according to claim 1 is characterized in that: Finite element modeling of secondary equipment is performed, specifically: Modeling is performed based on the topological structure of the secondary equipment. The secondary equipment consists of a measurement box, PCB board, steel structure, and low-voltage busbar. During modeling and simulation, the material and dimensions of the measurement box, the depth of the box slot, the material and outer diameter of the low-voltage busbar, the material and dimensions of the PCB board, and the material and dimensions of the steel structure are obtained. The three sides of the front of the measuring box are slit to serve as the door of the measuring box; the back of the measuring box is connected to the steel frame; a layer of PCB board is sandwiched inside the measuring box; During modeling, the PCB board is replaced by a dielectric board whose length and width are the same as the front plane of the measurement box.

7. The method for analyzing shielding effectiveness of secondary equipment on a series compensation platform under strong electromagnetic interference according to claim 6, characterized in that: The shielding effectiveness of the measuring box of the secondary equipment at different frequencies is calculated as follows: Model the secondary equipment by applying a fast transient overvoltage signal between the low-voltage busbar and the high-potential platform. Simulate the electric field distribution in the measurement box area and on the PCB surface of the secondary equipment. Calculate the electric field strength at a set point on the PCB with and without the measurement box. The set point on the PCB is where the sensitive component of the PCB is located. Calculate the shielding effectiveness SE of the measurement box at different frequencies according to the formula: Among them, E0 is the electric field strength at a certain point on the PCB board at the set frequency without the measurement box, and E c The electric field strength at a certain point on the PCB board after adding the measurement box at the set frequency.

8. The method for analyzing shielding effect of secondary equipment of a series compensation platform under strong electromagnetic interference according to claim 1 is characterized in that: Change the material of the secondary equipment to analyze the electromagnetic shielding effectiveness of different materials under the set overvoltage conditions, specifically: By changing the material of the measuring box of the secondary equipment, the electromagnetic shielding effectiveness of boxes of different materials under a set overvoltage condition is calculated; by changing the thickness and material of the PCB board, the electromagnetic shielding effectiveness of different dielectric boards under a set overvoltage condition is analyzed.

9. The method for analyzing shielding effectiveness of secondary equipment on a series compensation platform under strong electromagnetic interference according to claim 8, characterized in that: The changed box materials include copper and No. 10 steel, and the PCB board thickness includes 4, 6, and 8mm.

10. A system for analyzing shielding effectiveness of secondary equipment of a series compensation platform under strong electromagnetic interference using the method according to any one of claims 1 to 9, characterized in that: include: Primary equipment modeling module: used to perform multi-conductor modeling of the series compensation platform and busbar, and finite element modeling of the primary equipment of the series compensation platform, so as to establish a fast transient overvoltage simulation model of the primary equipment of the series compensation platform. The simulation obtains the fast transient overvoltage Uo between the low-voltage busbar and the high-potential platform at the location of the secondary equipment measurement box under the set overvoltage condition; Secondary equipment modeling module: used for finite element modeling of secondary equipment; Shielding effectiveness calculation module at different frequencies: used to model the secondary equipment and apply a fast transient overvoltage signal between the low-voltage bus and the high-potential platform, simulate the electric field distribution under the set overvoltage condition, and calculate the shielding effectiveness of the measuring box of the secondary equipment at different frequencies.

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