Broadband electromagnetic current transformer suitable for 10kV power distribution network intelligent fusion complete switch and performance detection method of broadband electromagnetic current transformer

Abstract

The invention relates to a broadband electromagnetic current transformer suitable for a 10kV power distribution network intelligent fusion complete switch and a performance detection method of the broadband electromagnetic current transformer. The broadband electromagnetic current transformer comprises a primary side current transformer and a secondary side current transformer, the primary side current transformer comprises a shielding shell, an outgoing line and a magnetic core arranged in the shielding shell; the magnetic core comprises a framework, a metal ring belt and an enameled wire; an annular groove is formed in the shielding shell, and an annular cutting gap communicated with the annular groove is formed in the circumferential wall of the inner ring of the shielding shell; the secondary side current transformer comprises a first reference layer, a second signal layer, a third signal layer and a fourth reference layer; high-frequency transient information generated in the fault process can be effectively collected, the bandwidth range, the measurement precision and the sensitivity of the transformer are improved, the secondary side current transformer adopts a four-layer PCB design, and double constraints of high-frequency signal transmission on a winding in a traditional Rogowski coil are overcome. According to the performance detection method, any field actual waveform can be simulated and output for sensor performance test so as to control the factory performance of a switch.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power equipment, and in particular to a broadband electromagnetic current transformer suitable for a 10kV distribution network intelligent fusion complete switch and a performance detection method thereof. Background Art

[0002] The distribution network is an important hub connecting the transmission link and power users, and its power supply reliability is directly related to the user experience. At present, based on the integrated primary and secondary pole-mounted switches, the fault analysis and section positioning of the distribution network line have been realized, and the procurement volume of the State Grid and China Southern Power Grid has increased year by year (> 4 billion yuan). However, due to the terminal layout and monitoring range of distribution automation, it is still difficult to achieve "precise positioning" for fault detection, and only km-level fault interval positioning can be achieved, especially in rural power grid areas or mountainous distribution networks. The distribution automation monitoring range is generally more than 5km. After the section judgment is successful, there are still a large number of fault inspection tasks, which has not fundamentally reduced the workload of traditional fault inspections.

[0003] Different from the existing distribution network fault section location method, the traveling wave method mainly uses the traveling wave phase and amplitude information generated by the fault to determine the fault phase, and determines the fault distance of the power supply line by measuring the transmission time of the current or voltage traveling wave signal between the measurement point and the fault point. It has the characteristics of fast response speed, no influence from the control of power electronic equipment, no influence from the distributed capacitance of the line and the transition resistance adjustment, high ranging accuracy, etc., and has extremely high application prospects in distribution networks.

[0004] The electromagnetic current sensors currently used for the measurement and protection of primary and secondary fusion switches mainly collect industrial frequency signals, but have low accuracy and poor frequency response characteristics for collecting high-frequency signals (traveling wave signals), which makes it difficult to further use the high-frequency signal components for in-depth fault analysis during a fault. At the same time, the current transformers currently used for primary and secondary intelligent fusion switches lack a reliable frequency characteristic detection method, resulting in uneven quality of existing equipment on the market, and reliable performance testing is needed before the equipment leaves the factory. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a wide-band electromagnetic current transformer suitable for 10kV distribution network intelligent fusion complete switch and a performance detection method thereof, so as to overcome the deficiencies in the above-mentioned prior art.

[0006] The technical solution of the present invention to solve the above technical problems is as follows: a wide-band electromagnetic current transformer suitable for a 10kV distribution network intelligent fusion complete switch, comprising a primary-side current transformer and a secondary-side current transformer;

[0007] The primary current transformer comprises a shielding shell, a lead wire and a magnetic core arranged in the shielding shell; the magnetic core comprises a frame, a metal ring belt and an enameled wire, and the metal ring belt is embedded in the frame; an annular groove is provided in the shielding shell, and an annular cut gap connected to the annular groove is provided on the inner circumferential wall of the shielding shell; one end of the enameled wire is wound along the circumference direction of the frame and then looped in the direction opposite to the direction of the coil; the positive and negative electrodes of the lead wire are respectively connected to the two ends of the enameled wire, and one end of the neutral wire of the lead wire is connected to the inner circle of the shielding shell;

[0008] The secondary side current transformer comprises a first reference layer, a second signal layer, a third signal layer and a fourth reference layer stacked in sequence;

[0009] One end winding of the primary current transformer is coupled with the distribution line, and the other end winding forms a loop with one end winding of the secondary current transformer. The other end winding of the secondary current transformer is connected to the source resistor R s Series connection.

[0010] The beneficial effects of the present invention are as follows: the current transformer of the present application can effectively collect high-frequency transient information generated by the fault process, and the primary-side current transformer is optimized in terms of magnetic core, winding process, thermal compensation, electromagnetic interference suppression, etc., which greatly improves the bandwidth range, measurement accuracy and sensitivity of the current transformer. The secondary-side current transformer adopts a 4-layer PCB design to overcome the dual constraints of high-frequency signal transmission on the winding in the traditional Rogowski coil.

[0011] Based on the above technical solution, the present invention can also be improved as follows.

[0012] Furthermore, the cross section of the skeleton is square.

[0013] Furthermore, the ratio of the inner and outer radii of the skeleton is 1:1.2 to 1.3.

[0014] Furthermore, the material of the magnetic core is Permalloy.

[0015] Furthermore, the via holes of the first reference layer, the fourth reference layer, the second signal layer and the third signal layer are aligned.

[0016] Furthermore, the lead-out wires use shielded twisted-pair wires.

[0017] The present invention also discloses a performance detection method for a wide-band electromagnetic current transformer applicable to a 10kV distribution network intelligent integrated switch set, which is used to detect the above-mentioned current transformer, and comprises the following steps:

[0018] Step S01: outputting an arbitrary waveform to a signal generator;

[0019] Step S02: A high-frequency broadband power amplifier amplifies and outputs an original waveform for detection, which is then tested by the current transformer to be tested;

[0020] Step S03: The acquisition card collects the detection data and uploads it to the broadband signal detection system to generate the output waveform after detection;

[0021] Step S04: The similarity between the original waveform and the output waveform is calculated by Pearson's waveform similarity comparison algorithm, and the performance of the current transformer to be tested is evaluated by the similarity to obtain excellent products, good products, qualified products and defective products.

[0022] Further, the specific steps of step S02 are:

[0023] Select appropriate driver-stage power amplifier tubes and final-stage power amplifier tubes, directly read the attenuation value of the network under test through a fixed attenuator, improve impedance matching, and buffer impedance changes;

[0024] The 1:1 balun is used for power distribution and power synthesis, and the 1:K balun and capacitors and inductors together form a broadband matching network.

[0025] Furthermore, the calculation formula of the Pearson's waveform similarity comparison algorithm in step S04 is as follows:

[0026]

[0027] Among them, ρ is the Pearson correlation coefficient, X and Y represent the output waveform data set and the original waveform data set respectively. They represent the average value of the output waveform sampling points and the average value of the original waveform sampling points respectively. ρ is used to measure the similarity between two variables. The closer the value is to 1, the greater the correlation between the two variables. The closer the value is to 0, the smaller the correlation between the two variables.

[0028] Furthermore, the judgment criteria for performance evaluation are specifically defined as:

[0029] f x上升 ≥97%, f x下降 ≥96%, f x整体 ≥96%, which is a superior product;

[0030] f x上升 ≥94%, f x下降 ≥93%0,f x整体 ≥93%, which means good product;

[0031] f x上升 ≥85%, f x下降 ≥85%, f x整体 ≥85%, that is, qualified products;

[0032] f x上升 <85%,f x下降 <85%,f x整体 <85%, it is a defective product;

[0033] Among them, f x上升 Indicates the similarity of the rising edge of the sensor test, f x下降 Indicates the similarity of the falling edge of the sensor test, f x整体 It indicates the overall similarity of sensor testing, where qualified products need to analyze the causes of errors and make improvements, while defective products are eliminated.

[0034] The beneficial effects of the present invention are: the surge generator can output a large current signal, but the frequency band is small and does not meet the requirements for broadband testing; while the signal generator can output a high-frequency signal, but the output signal amplitude is small and cannot be detected by the current transformer. The current test environment is difficult to meet the testing requirements of the traveling wave type primary and secondary fusion switch. The performance detection method of this application can simulate and output any actual waveform on site, and then provide sensor performance testing to control the factory performance of the switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural schematic diagram of the present invention;

[0036] Figure 2 It is a schematic diagram of the skeleton structure of the primary-side current transformer of the present invention;

[0037] Figure 3 It is a schematic diagram of the electromagnetic shielding structure of the primary-side current transformer of the present invention;

[0038] Figure 4 It is a schematic diagram of the electromagnetic compensation structure of the primary-side current transformer of the present invention;

[0039] Figure 5 It is a structural schematic diagram of the secondary side current transformer of the present invention;

[0040] Figure 6 is a performance detection flow chart of the current transformer of the present invention;

[0041] Figure 7 This is a flow chart for realizing the high-frequency band broadband power amplifier of the present invention;

[0042] Figure 8 This is a waveform diagram for waveform similarity analysis of the present invention.

[0043] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0044] 1. Primary-side current transformer; 11. Shielding shell; 111. Ring groove; 112. Ring-cut gap; 12. Lead wire; 13. Magnetic core; 131. Skeleton; 132. Metal ring belt; 133. Enameled wire; 2. Secondary-side current transformer; 21. First reference layer; 22. Second signal layer; 23. Third signal layer; 24. Fourth reference layer. DETAILED DESCRIPTION

[0045] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0046] like Figure 1 to Figure 5 As shown, in Example 1, a broadband electromagnetic current transformer suitable for a 10kV distribution network intelligent integrated switch, the primary side current transformer 1 includes a shielding shell 11, a lead wire 12 and a magnetic core 13 arranged in the shielding shell 11; the magnetic core 13 includes a skeleton 131, a metal ring belt 132 and an enameled wire 133, and the metal ring belt 132 is embedded in the skeleton 131; the change of ambient temperature will produce a thermal expansion effect on the transformer coil skeleton 131, resulting in the degradation of the transformer measurement accuracy and frequency response characteristics. When the ambient temperature changes from T0 to T1, theoretically, the current relative error of the primary transformer output and the temperature difference satisfy the following relationship:

[0047]

[0048] Where Δi is the current measurement error, i is the actual current value, T0 is the standard ambient temperature, T1 is the actual ambient temperature, ξ is the relative error factor. Figure 2 As shown in the present invention, a metal ring belt 132 made of non-magnetic material is embedded in the skeleton 131. When the temperature changes, the relative error factor generated by the metal ring belt 132 and the relative error factor generated by the magnetic core 13 can offset each other, thereby eliminating the influence of temperature changes on sensor measurement.

[0049] An annular groove 111 is provided in the shielding shell 11, and an annular cut slit 112 communicating with the annular groove 111 is provided on the inner circumferential wall of the shielding shell 11;

[0050] One end of the enameled wire 133 is wound along the circumference of the frame 131 and then looped back in the direction opposite to the direction of the coil. The vertical component of the interfering magnetic field cannot be completely eliminated by electromagnetic shielding. The present invention eliminates its influence by looping the coil, such as Figure 4 As shown, the loop is connected in series with the output end of the coil, and the vertical component interference magnetic field will generate induced voltages in opposite directions in the coil and the loop, thereby canceling each other out; and at this time, the loop is parallel to the magnetic flux lines, and no additional induced current will be generated, which will not affect the normal measurement of the transformer.

[0051] The positive and negative electrodes of the lead wire 12 are connected to the two ends of the enameled wire 133 respectively, and one end of the neutral wire of the lead wire 12 is connected to the inner circle of the shielding shell 11; when measuring, the other end of the neutral wire is connected to the negative electrode, which can effectively reduce the interference of the external magnetic field;

[0052] The secondary current transformer 2 comprises a first reference layer 21, a second signal layer 22, a third signal layer 23 and a fourth reference layer 24 which are stacked in sequence;

[0053] One end winding of the primary current transformer 1 is coupled with the power distribution line, and the other end winding forms a loop with one end winding of the secondary current transformer 2. The other end winding of the secondary current transformer 2 is connected to the source resistor R s Connected in series for FTU to process signals.

[0054] Electromagnetic current transformers are susceptible to interference from electromagnetic fields, resulting in more stray waveforms, which are difficult to completely eliminate at the hardware level and need to be dealt with from the sensor side. The present invention suppresses electromagnetic interference from two levels: electromagnetic shielding and electromagnetic compensation. The shielding shell 11 is made of copper-aluminum alloy with high magnetic permeability. The semi-enclosed shell of copper-aluminum alloy can reduce capacitive coupling and achieve electrostatic and magnetic field shielding. Since an annular groove 111 is provided inside the shielding shell 11 and no closed loop is formed, the magnetic flux to be measured cannot enter the coil core 13. A metal shielding body is used and reliably grounded. At the same time, an annular cut gap 112 is provided on the inner side of the shielding shell 11 to suppress the circulating current on the shielding shell 11.

[0055] The present invention divides the output current signal of the primary current transformer 1 into two paths, one path is a low-frequency signal, and the other path is a high-frequency signal. In order to overcome the dual constraints of high-frequency signal transmission on the winding in the traditional Rogowski coil and improve the fast transient current measurement capability of the secondary current transformer 2, the secondary current transformer 2 adopts a 4-layer PCB design, such as Figure 5 As shown, the present invention integrates the current sensing structure with the primary current output line by providing a complete reference plane for the signal winding, thereby realizing broadband sensing of the secondary side current transformer 2.

[0056] The current transformer of the present application can effectively collect high-frequency transient information generated by the fault process. The primary-side current transformer 1 is optimized in design from aspects such as the magnetic core, winding process, thermal compensation, and electromagnetic interference suppression, which greatly improves the bandwidth range, measurement accuracy, and sensitivity of the current transformer. The secondary-side current transformer 2 adopts a 4-layer PCB design to overcome the dual constraints of high-frequency signal transmission on the winding in the traditional Rogowski coil.

[0057] Embodiment 2: This embodiment is a further improvement on the basis of embodiment 1, and its details are as follows:

[0058] The cross section of the skeleton 131 is square. The cross section area of ​​the skeleton 131 with a square cross section is 1.3 times larger than that of the traditional circular structure, and the inductance of the mutual inductor is proportional to its cross section area, and the inductance is also increased to 1.3 times, so the sensor response speed is improved and the measurement accuracy is also slightly improved.

[0059] Embodiment 3, this embodiment is a further improvement on the basis of embodiment 1, and its details are as follows:

[0060] The ratio of the inner and outer radius of the skeleton 131 is 1:1.2-1.3. When the radius of the skeleton 131 of the coil of the primary current transformer 1 itself is much larger than the diameter of the cross section of the coil skeleton 131, the total magnetic flux in the coil is substantially equal to the magnetic field strength passing through the cross section. When measuring the current of the conductor to be measured, the position of the conductor to be measured should be able to be placed at will, so that the magnetic field strength on the cross section of the skeleton 131 can be substantially the same everywhere. In this case, the ratio of the inner and outer radii of the coil skeleton 131 should be between 1:1.2 and 1.3; in the specific implementation, the inner diameter a of the skeleton 131 is selected to be 7.55 cm, the outer diameter b is 9.15 cm, and the cross-sectional height h is 1 cm; the self-inductance and mutual inductance of the mutual inductor are positively correlated with the wire diameter of the enameled wire 133. In theory, the larger the wire diameter, the higher the accuracy of the mutual inductor and the wider the frequency band range. However, the increase in wire diameter will make the coil winding difficult and the increase in the gap between wire turns will lead to a decrease in accuracy. The present invention combines the design parameters of the skeleton 131 and selects 0.9 mm pure copper enameled wire 133. The coil is wound with semi-conductive corrugated paper instead of manual winding, which can reduce the objective error caused by manual winding and achieve a balance between the wire diameter and the gap between wire turns.

[0061] Embodiment 4: This embodiment is a further improvement on the basis of embodiment 1, and its details are as follows:

[0062] The material of the magnetic core 13 is Permalloy. Permalloy has a higher magnetic permeability in a weak magnetic field, and has a stronger weak current identification capability than silicon steel, iron crystal, and nanocrystal used in traditional mutual inductors, and is suitable for extremely high resistance (>1kΩ) ground fault detection in distribution networks.

[0063] Embodiment 5, this embodiment is a further improvement on the basis of embodiment 1, and its details are as follows:

[0064] The via holes of the first reference layer 21 and the fourth reference layer 24 are aligned with the via holes of the second signal layer 22 and the third signal layer 23. Thus, the shortest winding return loop can be obtained.

[0065] Embodiment 6: This embodiment is a further improvement on the basis of embodiment 1, and its details are as follows:

[0066] The lead wire 12 is a shielded twisted pair wire, which can effectively prevent the influence of external high-frequency magnetic field on the output signal during measurement.

[0067] like Figure 6 to Figure 8As shown, in Embodiment 7, a performance detection method for a wide-band electromagnetic current transformer applicable to a 10 kV distribution network intelligent integrated switch set is used to detect the current transformer of any one of Embodiments 1 to 6, comprising the following steps:

[0068] Step S01: outputting an arbitrary waveform to a signal generator; in a specific implementation, the arbitrary waveform is output to the signal generator through the host computer, and the signal is output immediately, or the GPS timing module outputs the signal to the signal generator at a specified time;

[0069] Step S02: A high-frequency broadband power amplifier amplifies and outputs an original waveform for detection, which is then tested by the current transformer to be tested;

[0070] Step S03: The acquisition card collects the detection data and uploads it to the broadband signal detection system to generate the output waveform after detection;

[0071] Step S04: The similarity between the original waveform and the output waveform is calculated by Pearson's waveform similarity comparison algorithm, and the performance of the current transformer to be tested is evaluated by the similarity to obtain excellent products, good products, qualified products and defective products.

[0072] The surge generator can output a large current signal, but the frequency band is small and does not meet the requirements for broadband testing; while the signal generator can output a high-frequency signal, but the output signal amplitude is small and cannot be detected by the current transformer. The current test environment is difficult to meet the testing requirements of the traveling wave type primary and secondary fusion switch. The performance detection method of this application can simulate the output of any actual waveform on site, and then provide sensor performance testing to control the factory performance of the switch.

[0073] Embodiment 8, this embodiment is a further improvement on the basis of embodiment 7, and its details are as follows:

[0074] The specific steps of step S02 are:

[0075] The balun is used to convert the signal from the balanced transmission mode of the coaxial cable to the unbalanced transmission mode, or from the unbalanced transmission mode to the balanced transmission mode, so as to realize the transmission of the signal between different circuits. It can solve the broadband matching problem that the centralized component matching cannot meet the requirements, so that the power amplifier can obtain a larger output power and gain in the whole frequency band.

[0076] Select appropriate driver-stage power amplifier tubes and final-stage power amplifier tubes, directly read the attenuation value of the network under test through a fixed attenuator, improve impedance matching, and buffer impedance changes;

[0077] The 1:1 balun is used for power distribution and power synthesis, and the 1:K balun and capacitors and inductors together form a broadband matching network, ultimately achieving K times amplification of the input signal.

[0078] Embodiment 9: This embodiment is a further improvement on the basis of embodiment 7, and its details are as follows:

[0079] The calculation formula of the Pearson waveform similarity comparison algorithm in step S04 is as follows:

[0080]

[0081] Among them, ρ is the Pearson correlation coefficient, X and Y represent the output waveform data set and the original waveform data set respectively. They represent the average value of the output waveform sampling points and the average value of the original waveform sampling points respectively. ρ is used to measure the similarity between two variables. The closer the value is to 1, the greater the correlation between the two variables. The closer the value is to 0, the smaller the correlation between the two variables.

[0082] Embodiment 10: This embodiment is a further improvement on the basis of embodiment 9, and its details are as follows:

[0083] The judgment criteria for performance evaluation are specifically defined as:

[0084] f x上升 ≥97%, f x下降 ≥96%, f x整体 ≥96%, which is a superior product;

[0085] f x上升 ≥94%, f x下降 ≥93%, f x整体 ≥93%, which means good product;

[0086] f x上升 ≥85%, f x下降 ≥85%, fx 整体 ≥85%, that is, qualified products;

[0087] f x上升 <85%,f x下降 <85%,f x整体 <85%, it is a defective product;

[0088] Among them, f x上升 Indicates the similarity of the rising edge of the sensor test, f x下降 Indicates the similarity of the falling edge of the sensor test, f x整体 It indicates the overall similarity of sensor testing, where qualified products need to analyze the causes of errors and make improvements, while defective products are eliminated.

[0089] The present invention selects the waveform rising edge, waveform falling edge and waveform overall similarity for performance evaluation and analysis, such as Figure 8As shown in the figure, the rising edge period of the waveform is from the start of recording to the moment when the waveform drops to the 3 / 4 peak of the first wave, which mainly reflects the high-frequency characteristics of the sensor (≥100kHz); the falling edge period is the remaining period of the waveform except the rising edge, which mainly reflects the low-frequency characteristics of the sensor (≤10kHz).

[0090] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A broadband electromagnetic current transformer suitable for 10kV distribution network intelligent integrated switch, characterized in that: It comprises a primary-side current transformer (1) and a secondary-side current transformer (2); The primary-side current transformer (1) comprises a shielding shell (11), a lead wire (12) and a magnetic core (13) arranged in the shielding shell (11); the magnetic core (13) comprises a frame (131), a metal ring belt (132) and an enameled wire (133), and the metal ring belt (132) is embedded in the frame (131); an annular groove (111) is provided in the shielding shell (11), and an annular cut gap (112) communicating with the annular groove (111) is provided on the inner circumferential wall of the shielding shell (11); one end of the enameled wire (133) is wound along the circumference direction of the frame (131) and then looped back in a direction opposite to the direction of the coil; the positive and negative electrodes of the lead wire (12) are respectively connected to the two ends of the enameled wire (133), and one end of the neutral wire of the lead wire (12) is connected to the inner circle of the shielding shell (11); The secondary-side current transformer (2) comprises a first reference layer (21), a second signal layer (22), a third signal layer (23) and a fourth reference layer (24) which are stacked in sequence; One end winding of the primary side current transformer (1) is coupled to the power distribution line, and the other end winding forms a loop with one end winding of the secondary side current transformer (2), and the other end winding of the secondary side current transformer (2) is connected to the source resistor R s Series connection.

2. A broadband electromagnetic current transformer suitable for 10kV distribution network intelligent integrated switch according to claim 1, characterized in that: The cross section of the frame (131) is square.

3. A broadband electromagnetic current transformer suitable for 10kV distribution network intelligent fusion switch set according to claim 2, characterized in that: The ratio of the inner and outer radii of the skeleton (131) is 1:1.2-1.

3.

4. A broadband electromagnetic current transformer suitable for 10kV distribution network intelligent fusion switch set according to claim 1, characterized in that: The material of the magnetic core (13) is Permalloy.

5. The broadband electromagnetic current transformer suitable for 10kV distribution network intelligent integrated switch according to claim 1, characterized in that: The first reference layer (21), the fourth reference layer (24), the second signal layer (22) and the third signal layer (23) are arranged in alignment with the via holes.

6. A broadband electromagnetic current transformer suitable for 10kV distribution network intelligent integrated switch according to claim 1, characterized in that: The lead-out wire (12) is a shielded twisted pair wire.

7. A performance detection method for a broadband electromagnetic current transformer applicable to a 10kV distribution network intelligent integrated switch, characterized in that: Used to detect the current transformer according to any one of claims 1 to 6, comprising the following steps: Step S01: outputting an arbitrary waveform to a signal generator; Step S02: A high-frequency broadband power amplifier amplifies and outputs an original waveform for detection, which is then tested by the current transformer to be tested; Step S03: The acquisition card collects the detection data and uploads it to the broadband signal detection system to generate the output waveform after detection; Step S04: The similarity between the original waveform and the output waveform is calculated by Pearson's waveform similarity comparison algorithm, and the performance of the current transformer to be tested is evaluated by the similarity to obtain excellent products, good products, qualified products and defective products.

8. The performance detection method of a wide-band electromagnetic current transformer applicable to a 10kV distribution network intelligent integrated switch according to claim 7, characterized in that: The specific steps of step S02 are: Select appropriate driver-stage power amplifier tubes and final-stage power amplifier tubes, directly read the attenuation value of the network under test through a fixed attenuator, improve impedance matching, and buffer impedance changes; The 1:1 balun is used for power distribution and power synthesis, and the 1:K balun and capacitors and inductors together form a broadband matching network.

9. The performance detection method of a wide-band electromagnetic current transformer applicable to a 10kV distribution network intelligent integrated switch according to claim 7, characterized in that: The Pearson's waveform similarity comparison algorithm in step S04 is calculated by the following formula: Among them, ρ is the Pearson correlation coefficient, X and Y represent the output waveform data set and the original waveform data set respectively. They represent the average value of the output waveform sampling points and the average value of the original waveform sampling points respectively. ρ is used to measure the similarity between two variables. The closer the value is to 1, the greater the correlation between the two variables. The closer the value is to 0, the smaller the correlation between the two variables.

10. The performance detection method of a wide-band electromagnetic current transformer applicable to a 10kV distribution network intelligent integrated switch according to claim 9, characterized in that: The judgment criteria for the performance evaluation are specifically defined as: f x上升 ≥97%, f x下降 ≥96%, f x整体 ≥96%, which is a superior product; f x上升 ≥94%, f x下降 ≥93%, f x整体 ≥93%, which means good product; f x上升 ≥85%, f x下降 ≥85%, f x整体 ≥85%, that is, qualified products; f x上升 <85%,f x下降 <85%,f x整体 <85%, it is a defective product; Among them, f x上升 Indicates the similarity of the rising edge of the sensor test, f x下降 Indicates the similarity of the falling edge of the sensor test, f x整体 It indicates the overall similarity of sensor testing, where qualified products need to analyze the causes of errors and make improvements, while defective products are eliminated.

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