Active filtering method and device applied to electromagnetic interference resistance of GIS secondary equipment

Abstract

The application discloses an active filtering method and device applied to anti-electromagnetic interference of GIS secondary equipment, a target filter is designed by connecting a passive filter and an active filter in series according to filtering requirements, and in order to guarantee the filtering effect of the designed target filter, it is required to judge whether the filtering effect of the target filter reaches preset requirements before use. When the filtering effect of the target filter reaches the preset requirements, the target filter is added between primary equipment and secondary equipment of a GIS system, effective filtering of VFTO noise entering the secondary equipment is realized, and the reliability and service life of the secondary equipment are improved. The influence of VFTO noise generated by the action of an isolating switch in the GIS system when being electrified on the secondary equipment is solved.

Description

Technical Field

[0001] This invention relates to the field of signal integrity technology, and more specifically, to an active filtering method and apparatus for electromagnetic interference suppression in GIS secondary equipment. Background Technology

[0002] Gas-Insulated Switchgear (GIS) is increasingly widely used in power systems due to its compact structure, reliable operation, and small footprint. However, because the components of a GIS are too compact, the moving contact moves slowly (approximately 1 ± 0.2 m / s) during the operation of the disconnecting switch or circuit breaker. This slow movement leads to repeated breakdowns of the dielectric material between the contacts, causing dozens or even hundreds of arc reignitions. Each arc reignition caused by a breakdown results in a sudden drop in overvoltage between the contacts within a few nanoseconds. The resulting steep voltage wave propagates along the GIS busbar and equipment, reflecting back and forth to form a very fast transient overvoltage (VFTO) with high amplitude and frequency, causing electromagnetic interference to the GIS equipment.

[0003] Due to the distributed capacitance between the instrument transformer and the high-voltage bus, VFTO (Volatile Fluctuation Tolerance) can intrude into the secondary side of the instrument transformer through this capacitance, and then be conducted into the control room via cables, interfering with secondary equipment and threatening the safe operation of the entire system. Furthermore, some electronic instrument transformers, although not experiencing faults in disconnector switch operation projects, have generated abnormal outputs that could lead to relay protection malfunctions. It can be seen that VFTO generated by disconnector switch operation can not only cause damaging faults in electronic instrument transformers, but also lead to abnormal outputs, making VFTO suppression a current research hotspot in the power system field.

[0004] In high-speed PCB design, VFTO can be filtered out by adding a filter between the bus and secondary equipment. Passive filters utilize a network of LC energy storage components to achieve filtering. However, passive filter networks composed of these energy storage components are large in size and weight, and also expensive. Therefore, in comparison, active EMI filters, employing active technology, can effectively suppress EMI noise and can dynamically compensate and adjust the noise signal. Furthermore, active EMI filters use semiconductor devices, giving them significant advantages in size and weight compared to traditional passive filters. This aligns with the needs of integrated and high-density switching power supplies and adapts to the current trend of integrated power electronic equipment. Therefore, active EMI filters have received widespread attention in recent years.

[0005] Traditional passive filters mostly consist of discrete differential and common-mode inductors and X and Y capacitors. Since the impedance of both inductors and capacitors is closely related to frequency, in the low-frequency range, the inductor impedance is low and the capacitor impedance is high, resulting in poor filter performance determined by their impedance characteristics. To improve low-frequency performance, it is often necessary to increase the inductor or capacitor values, which inevitably leads to size and weight issues. This is particularly evident in high-power, high-frequency applications where the current is large, requiring thicker wire for inductor winding. Furthermore, to prevent saturation, the magnetic core cannot be too small, limiting the potential for size reduction in filter inductors using current materials and processes. In addition, actual products have requirements regarding the specifications and size of power converters. Single-stage filters often cannot meet electromagnetic compatibility standards, frequently necessitating the use of two or more stages. This increases cost, increases losses, and further increases the size and weight of the filter.

[0006] Therefore, existing technologies lack a technical solution to address the impact of VFTO noise generated by the operation of disconnecting switches when energized in GIS systems on secondary equipment. Summary of the Invention

[0007] To address at least one of the problems described in the background section, the present invention provides an active filtering method and apparatus for electromagnetic interference suppression in GIS secondary equipment.

[0008] According to one aspect of the present invention, an active filtering method for electromagnetic interference suppression in GIS secondary equipment is provided, comprising:

[0009] Determine whether the filtering effect of the target filter meets the preset requirements. The target filter is composed of a passive filter and an active filter connected in series.

[0010] When the filtering effect of the target filter meets the preset requirements, a target filter is added between the primary and secondary equipment of the gas-insulated combined electrical system, and the target signal entering the secondary equipment is filtered by the target filter.

[0011] Optionally, determining whether the filtering effect of the target filter meets the preset requirements includes:

[0012] A circuit model for the target filter is established based on the noise signal of the gas-insulated combined electrical system;

[0013] A black-box modeling method is used to establish an equivalent circuit model of the secondary equipment.

[0014] Connect the circuit models of the input signal and the target filter with the equivalent circuit model of the secondary equipment, and simulate and analyze whether the filtering effect of the target filter meets the preset requirements.

[0015] Optionally, the circuit model for establishing the target filter based on the noise signal of the gas-insulated combined electrical system includes:

[0016] Determine the topology of the active filter;

[0017] By connecting the passive filter and the active filter in series, a preliminary circuit model of the target filter is obtained.

[0018] Based on the topology of the active filter, the parameters of each circuit element in the preliminary circuit model of the target filter are determined, and the final circuit model of the target filter is obtained.

[0019] Optionally, the topology includes a topology control method, a compensation method used in the compensation stage, and a sampling method used in the sampling stage, and determining the topology of the active filter includes:

[0020] The topology control method of the active filter is determined to be feedback type;

[0021] The compensation stage at the input of the active filter is determined to use current compensation.

[0022] The sampling stage at the output of the active filter is determined to use voltage sampling.

[0023] Optionally, determining the parameters of each circuit element in the preliminary circuit model of the target filter includes:

[0024] Determine the first lower cutoff frequency of the preliminary circuit model of the target filter in the sampling stage;

[0025] Determine the upper cutoff frequency of the preliminary circuit model of the target filter in the compensation stage;

[0026] Determine the second lower cutoff frequency of the target filter's preliminary circuit model in the amplification stage;

[0027] Determine the insertion loss of the preliminary circuit model of the target filter;

[0028] Based on the first lower cutoff frequency, the upper cutoff frequency, the second lower cutoff frequency, and the insertion loss, the parameters of each circuit element in the preliminary circuit model of the target filter are determined.

[0029] Optionally, the step of using a black-box modeling method to establish an equivalent circuit model of the secondary equipment includes:

[0030] Determine the Z parameters of the secondary equipment;

[0031] Based on the Z-parameters of the secondary equipment, the impedance spectrum of the secondary equipment is processed in mathematical modeling software using a system identification method to obtain the S-domain expression of the impedance spectrum.

[0032] By using the vector matching method, the S-domain expression of the impedance spectrum is transformed to obtain the equivalent circuit model of the secondary device.

[0033] Optionally, the step of connecting the circuit model of the input signal and the target filter with the equivalent circuit model of the secondary device to simulate and analyze the filtering effect of the target filter includes:

[0034] The first side of the capacitor assembly is connected to the busbar of the gas-insulated combined electrical system, and the second side of the capacitor assembly is connected to the circuit model of the target filter. The capacitor assembly consists of a first capacitor and a second capacitor connected in series. The voltage of the first capacitor is greater than the voltage of the second capacitor, and the voltage on the first side of the capacitor assembly is greater than the voltage on the second side of the capacitor assembly.

[0035] The input signal is taken from the second side of the capacitor assembly and transmitted to the circuit model of the target filter. The input signal is filtered by the circuit model of the target filter and then transmitted to the equivalent circuit model.

[0036] Electromagnetic interference tests were conducted on the equivalent circuit model, and the filtering effect of the target filter was analyzed based on the test results.

[0037] According to another aspect of the present invention, an active filtering device for electromagnetic interference suppression in GIS secondary equipment is provided, comprising:

[0038] The judgment module is used to determine whether the filtering effect of the target filter meets the preset requirements. The target filter is composed of a passive filter and an active filter connected in series.

[0039] The filtering module is used to add a target filter between the primary and secondary equipment of the gas-insulated combined electrical system when the filtering effect of the target filter meets the preset requirements. The target filter then filters the target signal entering the secondary equipment.

[0040] Optionally, the determination module includes:

[0041] The first submodule is used to establish a circuit model of the target filter based on the noise signal of the gas-insulated combined electrical system.

[0042] The second submodule is used to establish the equivalent circuit model of the secondary equipment using the black-box modeling method.

[0043] The simulation analysis submodule is used to connect the circuit model of the input signal and the target filter with the equivalent circuit model of the secondary equipment to simulate and analyze whether the filtering effect of the target filter meets the preset requirements.

[0044] Optionally, the first establishment submodule is specifically used for:

[0045] Determine the topology of the active filter;

[0046] By connecting the passive filter and the active filter in series, a preliminary circuit model of the target filter is obtained.

[0047] Based on the topology of the active filter, the parameters of each circuit element in the preliminary circuit model of the target filter are determined, and the final circuit model of the target filter is obtained.

[0048] Optionally, the topology includes a topology control method, a compensation method used in the compensation stage, and a sampling method used in the sampling stage, and determining the topology of the active filter includes:

[0049] The topology control method of the active filter is determined to be feedback type;

[0050] The compensation stage at the input of the active filter is determined to use current compensation.

[0051] The sampling stage at the output of the active filter is determined to use voltage sampling.

[0052] Optionally, determining the parameters of each circuit element in the preliminary circuit model of the target filter includes:

[0053] Determine the first lower cutoff frequency of the preliminary circuit model of the target filter in the sampling stage;

[0054] Determine the upper cutoff frequency of the preliminary circuit model of the target filter in the compensation stage;

[0055] Determine the second lower cutoff frequency of the target filter's preliminary circuit model in the amplification stage;

[0056] Determine the insertion loss of the preliminary circuit model of the target filter;

[0057] Based on the first lower cutoff frequency, the upper cutoff frequency, the second lower cutoff frequency, and the insertion loss, the parameters of each circuit element in the preliminary circuit model of the target filter are determined.

[0058] Optionally, the second establishment submodule is specifically used for:

[0059] Determine the Z parameters of the secondary equipment;

[0060] Based on the Z-parameters of the secondary equipment, the impedance spectrum of the secondary equipment is processed in mathematical modeling software using a system identification method to obtain the S-domain expression of the impedance spectrum.

[0061] By using the vector matching method, the S-domain expression of the impedance spectrum is transformed to obtain the equivalent circuit model of the secondary device.

[0062] Optionally, the simulation analysis submodule is specifically used for:

[0063] The first side of the capacitor assembly is connected to the busbar of the gas-insulated combined electrical system, and the second side of the capacitor assembly is connected to the circuit model of the target filter. The capacitor assembly consists of a first capacitor and a second capacitor connected in series. The voltage of the first capacitor is greater than the voltage of the second capacitor, and the voltage on the first side of the capacitor assembly is greater than the voltage on the second side of the capacitor assembly.

[0064] The input signal is taken from the second side of the capacitor assembly and transmitted to the circuit model of the target filter. The input signal is filtered by the circuit model of the target filter and then transmitted to the equivalent circuit model.

[0065] Electromagnetic interference tests were conducted on the equivalent circuit model, and the filtering effect of the target filter was analyzed based on the test results.

[0066] According to another aspect of the present invention, a computer-readable storage medium is provided, the storage medium storing a computer program for performing the methods described in any of the above aspects of the present invention.

[0067] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising: a processor; a memory for storing executable instructions of the processor; the processor being configured to read the executable instructions from the memory and execute the instructions to implement the method described in any of the preceding aspects of the present invention.

[0068] This invention designs a target filter consisting of a passive filter and an active filter connected in series, based on filtering requirements. To ensure the filtering effect of the designed target filter, it is necessary to determine whether the filtering effect meets the preset requirements before use. When the filtering effect of the target filter meets the preset requirements, by adding the target filter between the primary and secondary equipment in the GIS system, the VFTO noise entering the secondary equipment is effectively filtered out, improving the reliability and service life of the secondary equipment. This invention also solves the problem of the impact of VFTO noise generated by the operation of disconnect switches when energized in the GIS system on the secondary equipment. Attached Figure Description

[0069] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures:

[0070] Figure 1 This is a flowchart illustrating an exemplary embodiment of the present invention for an active filtering method applied to electromagnetic interference suppression of GIS secondary equipment.

[0071] Figure 2This is a schematic diagram of the impedance spectrum of a secondary device provided in an exemplary embodiment of the present invention;

[0072] Figure 3 This is a schematic diagram of the equivalent circuit model of a secondary device provided in an exemplary embodiment of the present invention;

[0073] Figure 4 This is a schematic diagram showing the connection between the circuit model of the input signal and the target filter and the equivalent circuit model of the secondary device provided in an exemplary embodiment of the present invention.

[0074] Figure 5 This is a schematic diagram comparing the time domain of the signal before and after filtering, provided by an exemplary embodiment of the present invention;

[0075] Figure 6 This is a schematic diagram of the structure of an active filter device for electromagnetic interference suppression in GIS secondary equipment, provided by an exemplary embodiment of the present invention.

[0076] Figure 7 This is the structure of an electronic device provided in an exemplary embodiment of the present invention. Detailed Implementation

[0077] Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0078] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention.

[0079] Figure 1 A flowchart illustrating the active filtering method for electromagnetic interference suppression in GIS secondary equipment provided by this invention is shown. Figure 1 As shown, an active filtering method for electromagnetic interference suppression in GIS secondary equipment includes:

[0080] Step S10: Determine whether the filtering effect of the target filter meets the preset requirements, wherein the target filter is composed of a passive filter and an active filter connected in series;

[0081] Optionally, determining whether the filtering effect of the target filter meets the preset requirements includes: establishing a circuit model of the target filter based on the noise signal of the gas-insulated combined electrical system; establishing an equivalent circuit model of the secondary equipment using a black-box modeling method; connecting the input signal, the circuit model of the target filter, and the equivalent circuit model of the secondary equipment; and simulating and analyzing whether the filtering effect of the target filter meets the preset requirements.

[0082] In this invention, due to some inherent drawbacks of passive filters, researchers sought an alternative technical solution for EMI suppression. Studies revealed that active filters operate on a different principle than passive filters. Passive filters filter noise current in a circuit by utilizing the impedance characteristics of passive components such as inductors and capacitors. Active filters, on the other hand, utilize active cancellation technology, detecting noise and outputting a compensation current to reduce or eliminate noise in the circuit. In contrast, active filters, because they use active components, do not require increasing capacitor and inductor values ​​to enhance low-frequency filtering. The semiconductor components used are also easier to integrate into the circuit, resulting in smaller size and weight, which aligns better with current power converter development trends. Therefore, this invention combines passive and active filters to design a target filter based on the noise signal of a gas-insulated combined electrical system.

[0083] Optionally, the step of establishing a circuit model for the target filter based on the noise signal of the gas-insulated combined electrical system includes: determining the topology of the active filter; connecting the passive filter and the active filter in series to obtain a preliminary circuit model of the target filter; and determining the parameters of each circuit element in the preliminary circuit model of the target filter based on the topology of the active filter to obtain the final circuit model of the target filter.

[0084] Optionally, the topology includes a topology control method, a compensation method used in the compensation stage, and a sampling method used in the sampling stage. Furthermore, determining the topology of the active filter includes: determining that the topology control method of the active filter is feedback-type; determining that the compensation stage at the input of the active filter uses a current compensation method; and determining that the sampling stage at the output of the active filter uses a voltage sampling method.

[0085] In this embodiment of the invention, the specific steps for designing a target filter include:

[0086] 1) Determine the topology of the active filter. Specifically: Feedforward topologies have few types (only two), limiting their application range. They also have an inherent disadvantage: achieving high control precision is difficult. In active EMI filtering applications, feedback control is easier and less costly to achieve higher insertion loss. Therefore, the control method for the active filter was ultimately determined to be feedback.

[0087] 2) The compensation stage at the input of the active filter is determined to use current compensation. Specifically, the function of the compensation stage is to feed the compensation signal back into the cable to cancel out the noise signal. There are two types of compensation stages: voltage compensation and current compensation. Voltage compensation uses a transformer to apply the compensation voltage to the cable. The winding direction is the same as in a typical current sampling circuit. The transformer will be very large, much larger than the current transformer used for current sampling, which contradicts the goal of using an active filter to reduce its size. Therefore, when the rated operating current is high, voltage compensation should be avoided as much as possible.

[0088] Current compensation injects compensation current into the cable using a capacitor. Essentially, this is equivalent to allowing the noise current to flow down through the compensation stage instead of towards the load. Like voltage sampling, current compensation offers the advantage of small size. The input of an active filter is a passive filter. Before the passive filter design is complete, the impedance of the active filter's input cannot be determined, making it impossible to select the compensation stage type based on impedance and topology selection rules. Therefore, the compensation stage type can be chosen from an engineering application perspective. Voltage sampling is unsuitable for applications with high rated operating current; therefore, current compensation is chosen for the active filter's input.

[0089] 3) The sampling stage at the output of the active filter should use voltage sampling. Specifically, the sampling stage extracts the noise signal from the cable and outputs it to the amplification stage; it is essentially a noise separation network. There are two types of sampling stages: voltage sampling and current sampling. The output impedance of the active filter is the same as the system load impedance, which is high. According to topology selection rules, voltage sampling corresponds to high impedance, and current sampling corresponds to low impedance. Therefore, for a feedback topology, the sampling stage at the output of the active filter should use voltage sampling.

[0090] Optionally, determining the parameters of each circuit element in the preliminary circuit model of the target filter includes: determining the first lower cutoff frequency of the preliminary circuit model of the target filter in the sampling stage; determining the upper cutoff frequency of the preliminary circuit model of the target filter in the compensation stage; determining the second lower cutoff frequency of the preliminary circuit model of the target filter in the amplification stage; determining the insertion loss of the preliminary circuit model of the target filter; and determining the parameters of each circuit element in the preliminary circuit model of the target filter based on the first lower cutoff frequency, the upper cutoff frequency, the second lower cutoff frequency, and the insertion loss.

[0091] In this embodiment of the invention, the parameters of the circuit elements in the circuit model of the target filter are designed as follows:

[0092] Because the sampling stage has high-pass characteristics, the lower cutoff frequency is f. sThat is, only frequencies above the lower cutoff frequency f s Only a common-mode signal can pass through the sampling stage and enter the amplification stage without distortion.

[0093] The amplification stage is an inverting amplifier, essentially a negative feedback system consisting of an operational amplifier and its external feedback circuit. The operational amplifier is the core component of the amplification stage, and its open-loop gain is the main factor determining its performance. The upper cutoff frequency in the amplification stage is f. A That is, only frequencies below the upper limit cutoff frequency f A Only signals that are not distorted can pass through the amplification stage and enter the compensation stage.

[0094] The compensation stage has high-pass characteristics, with a lower cutoff frequency of f. c Similarly, only frequencies above the lower cutoff frequency f c Only then can the signal be loaded onto the cable without distortion through the compensation process.

[0095] Analysis of the noise spectrum reveals that the active filter needs to achieve a 20dB insertion loss in the 20kHz–100kHz frequency band. Therefore, the 20kHz–100kHz frequency band must be placed within the operating bandwidth of the active filter, meaning the lowest frequency of 20kHz must be higher than the lower cutoff frequency f. s f c The highest frequency of 100kHz is lower than the upper limit cutoff frequency f. A In the design, to ensure sufficient insertion loss, the lower cutoff frequency f is set for the lowest frequency of 20kHz. s f c If we design to half of that frequency, then f s f c The upper limit cutoff frequency is 10kHz; while for the highest frequency of 100kHz, the upper limit cutoff frequency is f. A If the design frequency is approximately twice that of the frequency, then f A Greater than 200 kHz.

[0096] The formula for VCCS feedback insertion loss is:

[0097]

[0098] Where IL is the insertion loss, and Z... S Z is the source impedance. L Let G be the load impedance and G be the filter gain.

[0099] In summary, the constraints for designing the circuit component parameters of the target filter are as follows:

[0100]

[0101] Therefore, based on the above constraints, the parameters of each circuit element in the preliminary circuit model of the target filter can be determined.

[0102] Optionally, the step of using a black-box modeling method to establish an equivalent circuit model of the secondary equipment includes: determining the Z parameters of the secondary equipment; based on the Z parameters of the secondary equipment, using a system identification method, processing the impedance spectrum of the secondary equipment in mathematical modeling software to obtain the S-domain expression of the impedance spectrum; and transforming the S-domain expression of the impedance spectrum through a vector matching method to obtain the equivalent circuit model of the secondary equipment.

[0103] In this embodiment of the invention, black-box modeling refers to treating a device without internal structural information as a black box and obtaining an equivalent circuit model by analyzing its input-output characteristics. In this equivalent circuit model, the circuit elements have no specific physical meaning. After measurement, the Z-parameters of the secondary device and load are obtained. Using system identification methods, the signal impedance spectrum data is processed in mathematical modeling software (MATLAB) to obtain the S-domain expression of the signal. Then, through vector matching, the equivalent circuit model of the secondary device and load impedance is obtained.

[0104] In this embodiment of the invention, the impedance spectrum of the secondary device is as follows: Figure 2 As shown. In MATLAB, the S-domain expression of the impedance spectrum is obtained using the system identification method:

[0105]

[0106] Transform Z(s) into its form using MATLAB.

[0107]

[0108] Based on Y(s), we can obtain the following: Figure 3 The equivalent circuit model of the secondary device is shown.

[0109] Optionally, the step of connecting the input signal, the circuit model of the target filter, and the equivalent circuit model of the secondary equipment to simulate and analyze the filtering effect of the target filter includes: connecting the first side of the capacitor assembly to the busbar of the gas-insulated combined electrical system, and connecting the second side of the capacitor assembly to the circuit model of the target filter, wherein the capacitor assembly consists of a first capacitor and a second capacitor connected in series, the voltage of the first capacitor is greater than the voltage of the second capacitor, and the voltage on the first side of the capacitor assembly is greater than the voltage on the second side of the capacitor assembly; taking the input signal from the second side of the capacitor assembly, transmitting the input signal to the circuit model of the target filter, filtering the input signal through the circuit model of the target filter, and transmitting the filtered signal to the equivalent circuit model; performing electromagnetic interference testing on the equivalent circuit model, and analyzing the filtering effect of the target filter based on the test results.

[0110] In an embodiment of the present invention, Figure 4 A schematic diagram showing the connection between the circuit models of the input signal, the target filter, and the equivalent circuit model of the secondary equipment is provided. Figure 4 As shown, the capacitor assembly consists of a first capacitor (corresponding to...) Figure 4 The high-voltage capacitor C1) and the second capacitor are connected in series (corresponding to Figure 4 The system consists of a low-voltage capacitor (C2). The first side (high-voltage side) of the capacitor assembly is connected to the GIS system bus, and the second side (low-voltage side) is connected to the target filter, utilizing a capacitor divider between the high-voltage and low-voltage sides. The target filter includes a sampling stage, an amplification stage, and a compensation stage. Next, the input signal is filtered using the target filter's circuit model. The filtered and noise-reduced signal is then input to the equivalent circuit model of secondary equipment (e.g., but not limited to power supply systems and electronic transformer signal processing circuits), and the filtered signal is transmitted to the equivalent circuit model. Finally, electromagnetic interference testing is performed on the equivalent circuit model, and the filtering effect of the target filter is analyzed based on the test results.

[0111] Step S20: When the filtering effect of the target filter meets the preset requirements, a target filter is added between the primary and secondary equipment of the gas-insulated combined electrical system, and the target signal entering the secondary equipment is filtered by the target filter.

[0112] In this embodiment of the invention, when the filtering effect of the target filter meets the preset requirements, a target filter can be added between the primary and secondary equipment of the gas-insulated combined electrical system. The target filter then filters the target signal entering the secondary equipment. Experiments have shown that, according to this embodiment of the invention, a comparison of the signal frequency domain before and after filtering reveals that the fundamental signal remains almost unchanged, while the high-frequency signal shows significant attenuation. Figure 5 As shown in the time-domain comparison of the signals before and after filtering according to the embodiment of the present invention, it can be seen that the VFTO noise signal is effectively filtered out, and a useful signal is obtained. This achieves the goal of improving the stability and reliability of the secondary equipment.

[0113] This invention provides a more effective active filtering method for electromagnetic interference suppression in GIS secondary equipment. The topology of the active filter is determined, the parameters of the circuit elements in the filter circuit model are determined, and an equivalent circuit model of the secondary equipment is obtained by using a black-box modeling method. The input signal, the filter and the equivalent circuit of the secondary equipment are connected together, and the filtering effect of the filter is simulated and analyzed.

[0114] This invention provides an active filtering system for electromagnetic interference suppression in GIS secondary equipment. An active filter is designed based on filtering requirements. The input current and input voltage of the secondary equipment are processed to obtain the impedance spectrum of the secondary equipment. Then, the equivalent circuit model of the secondary equipment is obtained through black-box modeling and vector matching methods. Finally, the input signal, the active filter, and the equivalent circuit model of the secondary equipment are connected together, and the filtering effect of the filter is simulated and analyzed.

[0115] After the technical solution of this invention is transformed, it can be applied to reduce the adverse effects of GIS systems on secondary equipment, and to a certain extent solve the impact of VFTO caused by disconnector operation on secondary equipment. By improving the stability and reliability of electronic transformers in gas-insulated substations, it ensures the normal operation of electronic transformers and promotes the intelligent construction of power systems. After the technical solution of this invention is transformed, it can be applied to reduce power supply noise on chips in high-speed circuits, and to a certain extent solve the problems caused by unreasonable power impedance distribution network design, ensuring the normal operation of chips.

[0116] After the technical solution of this invention is transformed, it can be applied to solve the signal integrity problem of the high-speed image information processing board of air-to-air missiles, so that the image information processing board can correctly identify and process input signals and ensure the normal operation of digital integrated circuits such as DSP and FPGA in the image information processing board.

[0117] The technical solution of this invention has certain theoretical significance and engineering application value for improving the signal integrity and stability of electronic devices in signal systems. It can provide assistance for signal integrity research of electrical and electronic products, active filter design, and system signal integrity management. Based on active filter theory, this invention addresses the shortcomings of traditional studies on the impact of GIS systems on secondary equipment that lack consideration for active filters and equivalent circuit model design of secondary equipment.

[0118] Exemplary device

[0119] Figure 6 This is a schematic diagram of an active filter device for electromagnetic interference suppression in GIS secondary equipment, provided by an exemplary embodiment of the present invention. Figure 6 As shown, the device 600 includes:

[0120] The judgment module 610 is used to judge whether the filtering effect of the target filter meets the preset requirements, wherein the target filter is composed of a passive filter and an active filter connected in series.

[0121] The filtering module 620 is used to add a target filter between the primary and secondary equipment of the gas-insulated combined electrical system when the filtering effect of the target filter meets the preset requirements, and to filter the target signal entering the secondary equipment through the target filter.

[0122] Optionally, the determination module 610 includes:

[0123] The first submodule is used to establish a circuit model of the target filter based on the noise signal of the gas-insulated combined electrical system.

[0124] The second submodule is used to establish the equivalent circuit model of the secondary equipment using the black-box modeling method.

[0125] The simulation analysis submodule is used to connect the circuit model of the input signal and the target filter with the equivalent circuit model of the secondary equipment to simulate and analyze whether the filtering effect of the target filter meets the preset requirements.

[0126] Optionally, the first establishment submodule is specifically used for:

[0127] Determine the topology of the active filter;

[0128] By connecting the passive filter and the active filter in series, a preliminary circuit model of the target filter is obtained.

[0129] Based on the topology of the active filter, the parameters of each circuit element in the preliminary circuit model of the target filter are determined, and the final circuit model of the target filter is obtained.

[0130] Optionally, the topology includes a topology control method, a compensation method used in the compensation stage, and a sampling method used in the sampling stage, and determining the topology of the active filter includes:

[0131] The topology control method of the active filter is determined to be feedback type;

[0132] The compensation stage at the input of the active filter is determined to use current compensation.

[0133] The sampling stage at the output of the active filter is determined to use voltage sampling.

[0134] Optionally, determining the parameters of each circuit element in the preliminary circuit model of the target filter includes:

[0135] Determine the first lower cutoff frequency of the preliminary circuit model of the target filter in the sampling stage;

[0136] Determine the upper cutoff frequency of the preliminary circuit model of the target filter in the compensation stage;

[0137] Determine the second lower cutoff frequency of the target filter's preliminary circuit model in the amplification stage;

[0138] Determine the insertion loss of the preliminary circuit model of the target filter;

[0139] Based on the first lower cutoff frequency, the upper cutoff frequency, the second lower cutoff frequency, and the insertion loss, the parameters of each circuit element in the preliminary circuit model of the target filter are determined.

[0140] Optionally, the second establishment submodule is specifically used for:

[0141] Determine the Z parameters of the secondary equipment;

[0142] Based on the Z-parameters of the secondary equipment, the impedance spectrum of the secondary equipment is processed in mathematical modeling software using a system identification method to obtain the S-domain expression of the impedance spectrum.

[0143] By using the vector matching method, the S-domain expression of the impedance spectrum is transformed to obtain the equivalent circuit model of the secondary device.

[0144] Optionally, the simulation analysis submodule is specifically used for:

[0145] The first side of the capacitor assembly is connected to the busbar of the gas-insulated combined electrical system, and the second side of the capacitor assembly is connected to the circuit model of the target filter. The capacitor assembly consists of a first capacitor and a second capacitor connected in series. The voltage of the first capacitor is greater than the voltage of the second capacitor, and the voltage on the first side of the capacitor assembly is greater than the voltage on the second side of the capacitor assembly.

[0146] The input signal is taken from the second side of the capacitor assembly and transmitted to the circuit model of the target filter. The input signal is filtered by the circuit model of the target filter and then transmitted to the equivalent circuit model.

[0147] Electromagnetic interference tests were conducted on the equivalent circuit model, and the filtering effect of the target filter was analyzed based on the test results.

[0148] The active filtering device for electromagnetic interference suppression of GIS secondary equipment in the embodiments of the present invention corresponds to the active filtering method for electromagnetic interference suppression of GIS secondary equipment in another embodiment of the present invention, and will not be described again here.

[0149] Exemplary electronic devices

[0150] Figure 7 This is the structure of an electronic device provided in an exemplary embodiment of the present invention. For example... Figure 7 As shown, the electronic device 70 includes one or more processors 71 and a memory 72.

[0151] The processor 71 may be a central processing unit (CPU) or other form of processing unit with data processing and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions.

[0152] The memory 72 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 71 may execute the program instructions to implement the methods for information mining of historical change records and / or other desired functions of the software programs of the various embodiments of the present invention described above. In one example, the electronic device may also include an input device 73 and an output device 74, these components being interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0153] In addition, the input device 73 may also include, for example, a keyboard, a mouse, etc.

[0154] The output device 74 can output various information to the outside. The output device 74 may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, etc.

[0155] Of course, for the sake of simplicity, Figure 7 Only some of the components of the electronic device relevant to the present invention are shown, omitting components such as buses, input / output interfaces, etc. In addition, the electronic device may include any other suitable components depending on the specific application.

[0156] Exemplary computer program products and computer-readable storage media

[0157] In addition to the methods and apparatus described above, embodiments of the present invention may also be computer program products, which include computer program instructions that, when executed by a processor, cause the processor to perform the steps in the methods according to various embodiments of the present invention described in the "Exemplary Methods" section above.

[0158] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of the present invention. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0159] Furthermore, embodiments of the present invention may also be computer-readable storage media storing computer program instructions thereon, which, when executed by a processor, cause the processor to perform the steps of the methods for information mining of historical change records according to various embodiments of the present invention as described in the "Exemplary Methods" section above.

[0160] The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0161] The basic principles of the present invention have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in the present invention are merely examples and not limitations, and should not be considered as essential features of each embodiment of the present invention. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the present invention to the necessity of employing the aforementioned specific details.

[0162] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For system embodiments, since they largely correspond to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0163] The block diagrams of devices, systems, devices, and systems involved in this invention are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, systems, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0164] The methods and systems of the present invention may be implemented in many ways. For example, they may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above-described order of steps for the methods is for illustrative purposes only, and the steps of the methods of the present invention are not limited to the order specifically described above unless otherwise specifically stated. Furthermore, in some embodiments, the present invention may also be implemented as a program recorded on a recording medium, the program comprising machine-readable instructions for implementing the methods according to the present invention. Thus, the present invention also covers recording media storing programs for performing the methods according to the present invention.

[0165] It should also be noted that in the systems, apparatus, and methods of the present invention, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered equivalents of the present invention. The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the invention. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the invention. Therefore, the invention is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

[0166] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the invention to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

Claims

1. An active filtering method for electromagnetic interference suppression in GIS secondary equipment, characterized in that, include: Determine whether the filtering effect of the target filter meets the preset requirements. The target filter is composed of a passive filter and an active filter connected in series. When the filtering effect of the target filter meets the preset requirements, a target filter is added between the primary and secondary equipment of the gas-insulated combined electrical system, and the target signal entering the secondary equipment is filtered by the target filter; The determination of whether the filtering effect of the target filter meets the preset requirements includes: A circuit model for the target filter is established based on the noise signal of the gas-insulated combined electrical system; A black-box modeling method is used to establish an equivalent circuit model of the secondary equipment. Connect the circuit model of the input signal and the target filter with the equivalent circuit model of the secondary equipment, and simulate and analyze whether the filtering effect of the target filter meets the preset requirements. The circuit model for establishing the target filter based on the noise signal of the gas-insulated combined electrical system includes: Determine the topology of the active filter; By connecting the passive filter and the active filter in series, a preliminary circuit model of the target filter is obtained. Based on the topology of the active filter, the parameters of each circuit element in the preliminary circuit model of the target filter are determined, and the final circuit model of the target filter is obtained. The topology includes a topology control method, a compensation method used in the compensation stage, and a sampling method used in the sampling stage. Furthermore, determining the topology of the active filter includes: The topology control method of the active filter is determined to be feedback type; The compensation stage at the input of the active filter is determined to use current compensation. The sampling stage at the output of the active filter is determined to use voltage sampling. The parameters of each circuit element in the preliminary circuit model of the target filter include: Determine the first lower cutoff frequency of the preliminary circuit model of the target filter in the sampling stage; Determine the upper cutoff frequency of the preliminary circuit model of the target filter in the compensation stage; Determine the second lower cutoff frequency of the target filter's preliminary circuit model in the amplification stage; Determine the insertion loss of the preliminary circuit model of the target filter; Based on the first lower cutoff frequency, the upper cutoff frequency, the second lower cutoff frequency, and the insertion loss, the parameters of each circuit element in the preliminary circuit model of the target filter are determined. The method of using black-box modeling to establish the equivalent circuit model of the secondary equipment includes: Determine the secondary equipment Z parameter; Based on secondary equipment Z The parameters are obtained by processing the impedance spectrum of the secondary equipment in mathematical modeling software using a system identification method. S Domain expression; By using the vector matching method, the impedance spectrum... S The domain expression is transformed to obtain the equivalent circuit model of the secondary device.

2. The method according to claim 1, characterized in that, The step of connecting the circuit model of the input signal and the target filter with the equivalent circuit model of the secondary device to simulate and analyze the filtering effect of the target filter includes: The first side of the capacitor assembly is connected to the busbar of the gas-insulated combined electrical system, and the second side of the capacitor assembly is connected to the circuit model of the target filter. The capacitor assembly consists of a first capacitor and a second capacitor connected in series. The voltage of the first capacitor is greater than the voltage of the second capacitor, and the voltage on the first side of the capacitor assembly is greater than the voltage on the second side of the capacitor assembly. The input signal is taken from the second side of the capacitor assembly and transmitted to the circuit model of the target filter. The input signal is filtered by the circuit model of the target filter and then transmitted to the equivalent circuit model. Electromagnetic interference tests were conducted on the equivalent circuit model, and the filtering effect of the target filter was analyzed based on the test results.

3. An active filtering device for electromagnetic interference suppression in GIS secondary equipment, characterized in that, include: The judgment module is used to determine whether the filtering effect of the target filter meets the preset requirements. The target filter is composed of a passive filter and an active filter connected in series. The filtering module is used to add a target filter between the primary and secondary equipment of the gas-insulated combined electrical system when the filtering effect of the target filter meets the preset requirements, and to filter the target signal entering the secondary equipment through the target filter. The judgment module includes: The first submodule is used to establish a circuit model of the target filter based on the noise signal of the gas-insulated combined electrical system. The second submodule is used to establish the equivalent circuit model of the secondary equipment using the black-box modeling method. The simulation analysis submodule is used to connect the circuit model of the input signal and the target filter with the equivalent circuit model of the secondary equipment to simulate and analyze whether the filtering effect of the target filter meets the preset requirements. Specifically, the first establishment submodule is used for: Determine the topology of the active filter; By connecting the passive filter and the active filter in series, a preliminary circuit model of the target filter is obtained. Based on the topology of the active filter, the parameters of each circuit element in the preliminary circuit model of the target filter are determined, and the final circuit model of the target filter is obtained. The topology includes a topology control method, a compensation method used in the compensation stage, and a sampling method used in the sampling stage. Furthermore, determining the topology of the active filter includes: The topology control method of the active filter is determined to be feedback type; The compensation stage at the input of the active filter is determined to use current compensation. The sampling stage at the output of the active filter is determined to use voltage sampling. The parameters of each circuit element in the preliminary circuit model of the target filter include: Determine the first lower cutoff frequency of the preliminary circuit model of the target filter in the sampling stage; Determine the upper cutoff frequency of the preliminary circuit model of the target filter in the compensation stage; Determine the second lower cutoff frequency of the target filter's preliminary circuit model in the amplification stage; Determine the insertion loss of the preliminary circuit model of the target filter; Based on the first lower cutoff frequency, the upper cutoff frequency, the second lower cutoff frequency, and the insertion loss, the parameters of each circuit element in the preliminary circuit model of the target filter are determined. The second establishment submodule is specifically used for: Determine the secondary equipment Z parameter; Based on secondary equipment Z The parameters are obtained by processing the impedance spectrum of the secondary equipment in mathematical modeling software using a system identification method. S Domain expression; By using the vector matching method, the impedance spectrum... S The domain expression is transformed to obtain the equivalent circuit model of the secondary device.

4. The apparatus according to claim 3, characterized in that, The simulation analysis submodule is specifically used for: The first side of the capacitor assembly is connected to the busbar of the gas-insulated combined electrical system, and the second side of the capacitor assembly is connected to the circuit model of the target filter. The capacitor assembly consists of a first capacitor and a second capacitor connected in series. The voltage of the first capacitor is greater than the voltage of the second capacitor, and the voltage on the first side of the capacitor assembly is greater than the voltage on the second side of the capacitor assembly. The input signal is taken from the second side of the capacitor assembly and transmitted to the circuit model of the target filter. The input signal is filtered by the circuit model of the target filter and then transmitted to the equivalent circuit model. Electromagnetic interference tests were conducted on the equivalent circuit model, and the filtering effect of the target filter was analyzed based on the test results.

5. A computer-readable storage medium, characterized in that, The storage medium stores a computer program for performing the method described in any one of claims 1-2.

6. An electronic device, characterized in that, The electronic device includes: processor; Memory used to store the processor's executable instructions; The processor is configured to read the executable instructions from the memory and execute the instructions to implement the method described in any one of claims 1-2.

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