Hundred kA impulse large current sensing device based on multi-composite magnetic core material

Abstract

The present invention belongs to the technical field of electrical measurement, and specifically discloses a hundred kA impulse large current sensing device based on multi-composite magnetic core materials. The device includes: a multi-composite magnetic core skeleton, a current winding coil, a parallel resistor, and a shielding housing; the multi-composite magnetic core skeleton is composed of at least two magnetic materials, the multi-turn current winding coil is distributed on the multi-composite magnetic core skeleton, and both ends of the parallel resistor are respectively connected to both ends of the current winding coil; the shielding housing is located outside the composite magnetic core skeleton; the current conductor to be measured axially penetrates the composite magnetic core skeleton, and the measurement output end of the current winding coil is connected to the output circuit. The present invention solves the technical problem that the existing impulse large current sensing device cannot meet the technical requirements of high-amplitude and high-accuracy impulse large current measurement.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrical measurement, and particularly relates to a megakiloampere impulse large current sensing device based on a multi-composite magnetic core material. Background Art

[0002] The high-amplitude impulse current measurement technology is the basic support technology for performance evaluation such as the current tolerance of lightning protection equipment and surge protectors, impulse grounding resistance measurement, distributed traveling wave fault location, lightning strike fault analysis and other scenarios. Therefore, the measurement accuracy of impulse large current directly affects the validity of evaluation data and results.

[0003] Impulse large current has characteristics such as high amplitude, short duration, and wide frequency coverage range. During the measurement process, it is accompanied by transient electro-magnetic-thermal-force coupling joint impact. With the continuous development of power system transmission technology, the amplitude of impulse current has been continuously increasing, and it has now reached up to 200 kA. The current amplitude of traditional impulse current dividers is difficult to exceed megakiloamperes. With the further increase of the impulse large current amplitude, the existing measurement devices are difficult to meet the requirements of domestic industry value calibration in terms of measurement amplitude range, waveform parameter types, performance calibration methods, etc. The theoretical system of traditional traceability methods is not perfect, and the measurement uncertainty is difficult to further reduce. Rogowski coils are easily affected by external factors such as eccentricity, and it is difficult to improve the measurement accuracy. Electromagnetic current sensors are extremely easy to saturate under the action of large current, and their high-frequency characteristics are limited.

[0004] Typical waveforms of impulse current are as Figure 1 shown, and its waveform characteristic parameters include three parameters: current peak value, front time T1, and tail time T2. The time parameters (T1 / T2) of typical impulse current waveforms to be measured are (1 / 20) μs, (4 / 10) μs, (8 / 20) μs, (10 / 350) μs, the rise time is several μs, the fall time is dozens of μs to hundreds of μs, and the waveform frequency content ranges from 0 Hz to several MHz, which puts extremely high requirements on the response characteristics and bandwidth of the measurement device.

[0005] The impulse current measurement device is a key measurement device for electrical equipment to conduct impulse current withstand tests. Its measurement accuracy directly affects the safety and economy of power equipment. An effective method to ensure the accuracy and consistency of quantity values is quantity value traceability, which makes the measurement results traceable to national standards or international standards through an uninterrupted chain with specified uncertainties. In recent years, with the continuous development of metrology technology and the continuous improvement of quality management systems, and the increasing export volume of China's measurement equipment, enterprises and research institutes have paid more attention to the quantity value traceability of the peak value and time parameters of impulse current measurement equipment, and need to continuously improve the technical capabilities and levels of China's impulse current standard measurement devices.

[0006] The standard impulse current measuring device is a key equipment in the traceability of impulse current values. As a reference standard, it transmits the standard values to impulse current measuring devices at all levels, continuously improving the measuring amplitude of the standard impulse current and the measuring accuracy of impulse current waveform parameters. Improving the measuring accuracy of impulse current waveform parameters is the direction of high-voltage and large-current metrology work.

[0007] The impulse current shunt is the earliest and most direct measurement method. Its measurement principle is based on Ohm's law. The impulse current shunt is essentially a measuring resistor. The current to be measured flows through the measuring resistor, generating a voltage across the measuring resistor. The waveform parameters of the current to be measured are obtained by using the voltage value to calculate the resistance value. The impulse current shunt generally adopts a coaxial structure, which has stable resistance, compact structure, small stray inductance, and excellent high-frequency response characteristics, and is commonly used for measuring impulse currents in the range of hundreds of kA. Due to the limitation of its measurement principle, the shunt needs to be connected in series to the current loop to be measured. When the current loop to be measured is compact and the installation position is limited, this measurement device cannot be used. When the amplitude of the current to be measured exceeds the range of hundreds of kA, the shunt heats up severely and cannot dissipate heat effectively, resulting in a change in resistance value and affecting the measurement accuracy. When the impulse current shunt measures a steep pulse impulse current, the skin effect under high-frequency signals may occur, resulting in low utilization rate of the resistor body and a change in resistance value; when measuring the impulse current waveform with a wide pulse width, due to the accumulation of thermal effects, its measured amplitude will be further reduced, unable to meet the increasing demand for impulse current measurement.

[0008] Using a magnetic core Rogowski coil as the impulse current standard, the magnetic core coil is wound with a single coil winding structure. When the amplitude and pulse width of the current to be measured increase, magnetic saturation is likely to occur. When using a single coil winding structure, it is impossible to simultaneously meet the requirements of output sensitivity, upper limit frequency, and response time, and it is difficult to measure impulse currents above hundreds of kA; due to the limitation of the magnetic core frequency band characteristics, it is difficult to respond to current waveforms with ultra-high frequency components.

[0009] Using a hollow Rogowski coil to measure the impulse large current waveform, since there is no magnetic core introduced, theoretically, it can measure impulse large current waveforms from hundreds of kA to several MA. The hollow winding coil is externally connected to a passive integration or active integration circuit to achieve the measurement of impulse large current. However, when the external integration circuit of the hollow Rogowski coil is a passive integration, its low-frequency characteristics are limited; when externally connected to an active integration, due to the introduction of the power supply loop, the current coil is extremely susceptible to interference from the spatial electric and magnetic fields, and it is difficult to improve the measurement accuracy, so it cannot be used as a standard measurement device for impulse current.

[0010] The most important parameters of the impulse large current waveform are the peak value, front time, and tail time. Existing various impulse large current measuring and sensing devices cannot accurately measure impulse large current waveforms above hundreds of kA, and there are problems such as poor response characteristics, inability to accurately reproduce the impulse large current waveform, inability to obtain the peak value and time characteristic parameters of the impulse current waveform, and inability to accurately obtain the standard value of the impulse large current. Summary of the Invention

[0011] The object of the present invention is to provide a hundred kA impulse large current sensing device based on multi-composite magnetic core materials, so as to solve the technical problem that the existing impulse large current sensing devices cannot meet the technical requirements of high-amplitude and high-accuracy impulse large current measurement.

[0012] To achieve the above object, the present invention adopts the following technical solutions:

[0013] A hundred kA impulse large current sensing device based on multi-composite magnetic core materials, comprising: a multi-composite magnetic core skeleton, a current winding coil, a parallel resistor and a shielding housing; the above multi-composite magnetic core skeleton is composed of at least two magnetic materials in combination, the multi-turn current winding coil is distributed on the above multi-composite magnetic core skeleton, and both ends of the above parallel resistor are respectively connected to both ends of the above current winding coil; the above shielding housing is located outside the above composite magnetic core skeleton; the current conductor to be measured axially penetrates the above composite magnetic core skeleton, and the measurement output end of the above current winding coil is connected to the output circuit.

[0014] A design method for a hundred kA impulse large current sensing device based on multi-composite magnetic core materials, comprising: calculating the ampere-second number of the current waveform to be measured according to the waveform parameters of the current waveform to be measured; calculating the bandwidth requirement according to the frequency content of the current waveform to be measured; determining the proportion and superposition method of each material in the multi-composite magnetic core materials according to the bandwidth requirement; determining the size of the composite magnetic core skeleton based on the ampere-second number of the current waveform to be measured and the composite magnetic core materials; conducting a magnetic saturation characteristic test on the magnetic core materials to obtain the B-H curve data of the magnetic core materials; taking the sensitivity, upper cut-off frequency, lower cut-off frequency, winding resistance and heat generation of the current sensor as constraint conditions to determine the winding wire diameter, number of turns and number of segmented groups of the current winding coil; calculating the grouped induced voltage, inter-turn capacitance, equivalent inductance and capacitance to ground of the current winding coil, and conducting a rationality verification; in the case where the rationality verification is passed, determining the reliable working range of the pulse current coil according to the parameters of the sensing device.

[0015] A computer-readable storage medium, in which a computer program is stored, wherein the computer program is set to execute the above design method for a hundred kA impulse large current sensing device based on multi-composite magnetic core materials when running.

[0016] An electronic device, comprising a memory and a processor, wherein a computer program is stored in the above memory, and the above processor is set to execute the above design method for a hundred kA impulse large current sensing device based on multi-composite magnetic core materials through the computer program.

[0017] In the present invention, a multi-composite magnetic core framework is composed of at least two magnetic materials. A multi-turn current winding coil is distributed on the multi-composite magnetic core framework, and both ends of a parallel resistor are respectively connected to both ends of the current winding coil. A shielding shell is located outside the composite magnetic core framework. A current conductor to be measured axially penetrates the composite magnetic core framework, and the measurement output end of the current winding coil is connected to an output circuit. Based on the multi-composite magnetic core material as the winding framework of the current coil, with a multi-segment winding structure configuration, while ensuring the sensitivity of the sensing device, the response characteristics of the measurement device are optimized, the measured current amplitude and frequency band width are expanded, the measurement amplitude and bandwidth of the electromagnetic impulse current measurement device are greatly increased, the measurement uncertainty of the impulse current peak value and time parameters is reduced, the overall measurement technology level of large impulse currents is improved, and the technical problem that the existing large impulse current sensing devices cannot meet the technical requirements of high-amplitude and high-accuracy large impulse current measurement is solved. It can be widely used as a standard measurement device for impulse currents in impulse current equipment manufacturers, national high-voltage metrology stations, provincial-level electric power research institutes, meteorological research institutes, and other impulse current detection and calibration laboratories, greatly improving the overall technical level of impulse current equipment in our country. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of a typical impulse current waveform;

[0019] Figure 2 is a schematic structural diagram of a multi-kA impulse current sensing device based on multi-composite magnetic core material in an embodiment of the present invention;

[0020] Figure 3 is a schematic cross-sectional diagram of the multi-composite magnetic core framework in an embodiment of the present invention;

[0021] Figure 4 is a schematic diagram of the winding method of the current winding coil on the multi-composite magnetic core framework in an embodiment of the present invention;

[0022] Figure 5 is a schematic diagram of the measurement principle of the magnetic core current coil in an embodiment of the present invention;

[0023] Figure 6 is a schematic flow diagram of a design method of a multi-kA impulse current sensing device based on multi-composite magnetic core material in an embodiment of the present invention;

[0024] Figure 7 is a schematic flow diagram of a design method of a multi-kA impulse current sensing device based on multi-composite magnetic core material in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. According to the following description and the claims, the advantages and features of the present invention will be more clearly understood. It should be noted that the accompanying drawings are all in very simplified forms and use non-precise scales, only for the purpose of facilitating and clearly assisting in explaining the objectives of the embodiments of the present invention.

[0026] It should be noted that, in order to clearly illustrate the content of the present invention, the present invention specifically gives multiple embodiments to further explain different implementation manners of the present invention. Among them, the multiple embodiments are listed rather than exhaustive. In addition, for the sake of simplicity of description, the content already mentioned in the previous embodiments is often omitted in the subsequent embodiments. Therefore, the content not mentioned in the subsequent embodiments can be correspondingly referred to the previous embodiments.

[0027] Embodiment 1

[0028] A megakiloampere impulse large current sensing device based on a multi-composite magnetic core material, as Figure 2 shown, the device includes: a multi-composite magnetic core skeleton, a current winding coil, a parallel resistor, and a shielding housing; the multi-composite magnetic core skeleton is composed of at least two magnetic materials in combination, the multi-turn current winding coil is distributed on the multi-composite magnetic core skeleton, and both ends of the parallel resistor are respectively connected to both ends of the current winding coil; the shielding housing is located outside the composite magnetic core skeleton; the current conductor to be measured axially penetrates the composite magnetic core skeleton, and the measurement output end of the current winding coil is connected to the output circuit.

[0029] As an optional implementation manner, the current winding coil is distributed on the multi-composite magnetic core skeleton in a segmented form with multiple turns in a group, and multiple groups of current winding coils are connected in series.

[0030] As an optional implementation manner, a parallel resistor is connected in parallel to both ends of each group of current winding coils.

[0031] Based on the multi-composite magnetic core material as the winding skeleton of the current coil, adopting a multi-segmented winding structure configuration, while ensuring the sensitivity of the sensing device, the response characteristics of the measuring device are optimized, and the measured current amplitude and frequency band width are expanded.

[0032] As an optional implementation manner, the multi-composite magnetic core skeleton is composed of magnetic laminations of at least two materials in combination, and each material is evenly and symmetrically distributed.

[0033] As an optional implementation manner, the thickness of each layer of magnetic lamination does not exceed 10 μm, and each layer of magnetic lamination is annular.

[0034] Optionally, the magnetic laminations of each material are axially symmetrically distributed on the multi-composite magnetic core skeleton.

[0035] As an optional embodiment, the shielding shell includes a low-frequency band magnetic shielding shell, a high-frequency band magnetic shielding shell and an electric shielding shell. The low-frequency band magnetic shielding shell is used to shield low-frequency magnetic field interference signals within 1 MHz, and the high-frequency band magnetic shielding shell is used to shield high-frequency magnetic field interference signals above 1 MHz.

[0036] As an optional implementation, the high-frequency band magnetic shielding shell is located between the low-frequency band magnetic shielding shell and the electric shielding shell, and the electric shielding shell is located at the outermost layer.

[0037] As an optional implementation, the multi-composite magnetic core skeleton is wrapped with an insulating layer, and the outer layer of the winding current coil is wrapped with an insulating layer.

[0038] As an optional implementation, the magnetic material of the multi-composite magnetic core skeleton includes: ferrite, microcrystalline alloy, and Permalloy.

[0039] The core material of the multi-composite magnetic core skeleton is not limited to the composite composition of multiple laminated magnetic core materials such as ferrite, microcrystalline alloy, and Permalloy. Compared with a single magnetic core material, the composite magnetic core material has the advantages of wider frequency band characteristics and larger magnetic saturation range. In order to ensure the uniformity of the magnetic field strength in the magnetic core material, a variety of different composite magnetic core laminate materials are evenly and symmetrically distributed, and each layer of magnetic laminate material is annular with a thickness of no more than 10μm. The cross-section of the multi-composite magnetic core material is not limited to Figure 3 As shown. According to the actual needs of the current waveform to be measured, a variety of thin-film core materials are laminated and crimped into a ring-shaped composite core material of the required size, and its bandwidth can cover 0.1Hz~10MHz, ensuring full-band accurate measurement of exponential and rectangular impulse current waveforms.

[0040] The impact high current measurement is carried out by connecting multiple winding coils in series, which is not limited to Figure 4 As shown in the figure, the winding method of two consecutive groups is given, taking 6 turns per winding group as an example. A parallel resistor is connected to both ends of each winding coil. The multi-winding impact current sensor is equivalent to multiple parallel single-winding current coils. Its bandwidth is determined by the bandwidth of a single winding. Under the impact of large current, multiple balanced windings respond synchronously. Since the number of turns in a single winding is reduced, the response speed of the coil is effectively improved. Under the condition of the same core material, size, and shielding layer spacing, the capacitance of the multi-segment winding current sensor is m times smaller than that of the single-winding coil. The reduction in capacitance is conducive to increasing the upper cut-off frequency fH and the response speed.

[0041] To ensure good magnetic shielding performance of the current coil, a frequency-band segmented magnetic shielding housing is provided on the housing of the magnetic core winding coil, with the low-layer shielding layer on the inside and the high-frequency magnetic shielding layer on the outside. Among them, the high-frequency magnetic shielding housing is mainly used to shield high-frequency magnetic field interference signals above 1 MHz, and the low-frequency magnetic shielding housing is mainly used to shield low-frequency magnetic field interference signals within 1 MHz, achieving a good shielding effect in the full frequency band range of 0 Hz to MHz. At the same time, an electrical shielding housing is provided outside the low-frequency magnetic shielding housing to achieve a good electromagnetic shielding effect.

[0042] The measurement principle of the magnetic core current coil is not limited to as Figure 5 shown, the current to be measured passes through the magnetic core skeleton wound with a coil. When the current to be measured I(t) generates a magnetic field in space, when the current to be measured changes, a voltage U = Mdi / dt proportional to the current change rate will be induced at both ends of the coil wound on the magnetic core coil. M is the induction coefficient of the current coil, which is related to the size of the coil winding skeleton and the relative magnetic permeability (determined by the magnetic core material). Integrate the induced voltage of the current coil to obtain a voltage value proportional to the value of the current to be measured, and obtain the proportional coefficient of this current measurement device by comparing with a standard current measurement device.

[0043] In the embodiment of the present application, a non-contact magnetic core coil is used to measure large impulse currents, effectively avoiding heating caused by directly connecting to a large current circuit and realizing the possibility of measuring large currents of hundreds of kA; optimizing the existing magnetic core materials, stacking magnetic core materials with various different characteristics to achieve the superimposition of the advantages of multiple magnetic core materials, and ensuring the broadband response characteristics, high saturation magnetic field range value, and high relative magnetic permeability of the composite magnetic core material. Aiming at the problems of excessive turns of the magnetic core coil for hundreds of kA impulse large currents, oscillation and poor response characteristics caused by internal stray inductance and stray capacitance, the multi-winding coil is grouped. When measuring the impulse current waveform, multiple segmented windings respond simultaneously to reduce the response time; at the same time, distributed damping is performed on the multiple segmented windings to reduce the oscillation amplitude of the response waveform and reduce the measurement error, and finally achieve accurate measurement of the impulse large current waveform and parameters.

[0044] The hundreds of kA impulse large current sensing device based on multi-composite magnetic core materials specifically includes a composite magnetic core skeleton, an insulating layer wrapped around the magnetic core skeleton, a multi-turn current winding coil with multiple groups on the magnetic core skeleton, a parallel damping resistor at both ends of the multi-winding measurement coil, a measurement output end of the winding current coil, an outer insulating layer of the winding current coil, a low-frequency magnetic shielding housing, a high-frequency magnetic shielding housing, and an electrical shielding housing.

[0045] The winding skeleton of the current sensor adopts multi-composite magnetic core material. Different from the traditional single magnetic core material, the multi-composite magnetic core material is based on a composite composition of various laminated magnetic core materials such as ferrite, microcrystalline alloy, and Permalloy. Compared with the single magnetic core material, while ensuring a higher relative magnetic permeability, the composite magnetic core material has the advantages of wider frequency band characteristics and larger magnetic saturation range.

[0046] In order to ensure the uniformity of the magnetic field strength in the composite magnetic core material, various types of magnetic core lamination materials are evenly and symmetrically distributed and then crimped. The shape of the magnetic core material can be selected according to the size and shape requirements of the winding skeleton of the actual current sensor (it can be a circular ring or a hollow rectangle). The shape of the magnetic core can be a fixed structural core with a rigid structure or an open and closed structural core with a double C structure.

[0047] The area of the multi-layer composite core lamination material is exactly the same. To ensure the uniform penetration of the magnetic field in the core material, the thickness of the single-layer core material does not exceed 10μm. According to the needs of the actual current waveform to be measured, multiple (two or more) thin-film core materials are laminated and crimped into composite core materials of the required size and shape. Its bandwidth can cover 0.1Hz~10MHz, and its relative permeability can be flexibly adjusted from hundreds to hundreds of thousands, which not only ensures the effective acquisition of low-frequency current signals, but also ensures the accurate measurement of high-frequency signals and ensures the full-band accurate measurement of exponential and rectangular impulse current waveforms.

[0048] The magnetic permeability and structural parameters of the magnetic core material of the current sensor are calculated based on a comprehensive evaluation of the sensitivity coefficient of the current sensor, the number of winding turns and other parameters. The type of multi-composite material, the distribution of the laminations and the proportion of the number of layers of different core materials are further determined based on the determined magnetic permeability.

[0049] Different from the single winding winding method used in traditional electromagnetic impulse current transformers, the sensor proposed in this patent uses multiple segmented windings connected in series to measure large impulse currents. After the windings are segmented, the number of turns of a single-segment coil winding is less. After adopting a multi-winding design, when the core material, size, and shielding layer spacing are the same, the capacitance of the multi-segmented winding current sensor is m times smaller than that of a single winding coil. The reduction in capacitance is conducive to increasing the upper cutoff frequency. f H and response speed.

[0050] In terms of physical structure, the multiple segmented windings of the current sensor are connected in series. In terms of response characteristics, when the current to be measured is applied to the sensor, the multi-winding impact current sensor is equivalent to multiple parallel single-winding current coils responding synchronously. Its bandwidth is determined by the bandwidth of a single winding. Under the action of large impact current, multiple balanced windings respond synchronously. Since the number of turns is reduced, the response speed is effectively improved.

[0051] The segmented form of multiple windings in the sensor can adopt either a uniform segmentation method or a non-uniform segmentation method. When the voltage drop across the coil winding is extremely uneven at the moment when the current waveform to be measured is applied, the non-uniform segmentation method can optimize the uniformity of the voltage distribution on the winding coil, further improving the insulation performance of the current sensor. The winding segmentation method of the current sensor is comprehensively determined by the rise time of the waveform to be measured and the proportion of current content in each frequency band.

[0052] To further optimize the response characteristics of the current sensor, resistors are connected in parallel at both ends of each segmented winding. The resistance value of this parallel resistor is comprehensively determined by the number of coil turns, the sensitivity of the sensor, and the sensor bandwidth. The power of this resistor is determined by the voltage across the resistor and the loop current. This parallel resistor can not only act as a damping resistor to damp the oscillation caused by the self-inductance and parasitic capacitance of the coil, but also act as an integrating resistor.

[0053] To ensure good electromagnetic shielding performance of the sensor, a frequency-band segmented magnetic shielding housing is arranged outside the insulating layer of the magnetic core winding coil of the current sensor. The low-frequency shielding layer is on the inside and the high-frequency magnetic shielding layer is on the outside. The high-frequency magnetic shielding housing is mainly used to shield high-frequency magnetic field interference signals above 1 MHz, and the low-frequency magnetic shielding housing is mainly used to shield low-frequency magnetic field interference signals within 1 MHz, achieving a good shielding effect in the full frequency band range of 0 Hz to MHz. At the same time, an electric shielding housing is arranged outside the low-frequency magnetic shielding housing, finally achieving a good electromagnetic shielding effect.

[0054] In the embodiment of the present application, the current measurement amplitude, pulse width, and waveform frequency band range of the impulse current sensor are greatly improved; by adopting the method of composite superposition of multiple different magnetic core materials, the frequency band measurement range of the magnetic core material is effectively expanded, and its magnetic saturation range is greatly increased; the types and proportions of the constituent materials of the multi-composite magnetic core material can be flexibly determined according to the ampere-second number and frequency band range of the current waveform to be measured, and it is applicable to a wide range of measured current waveforms; through the structure of multi-winding segmentation, the single multi-turn winding is reconstructed into a multi-segment and few-turn winding, and the multi-segment windings respond to the same current to be measured synchronously, effectively improving the response speed and the upper cut-off frequency of the sensor; multiple resistors are connected in parallel at both ends of the multi-windings. This resistor can not only act as an integrating resistor, but also act as a distributed damping resistor, effectively suppressing the oscillation amplitude caused by the equivalent inductance and capacitance parameters in the coil when the current coil is affected by the impulse current; by adopting the combined shielding form of high- and low-frequency segmented magnetic shielding housings and electric shielding housings, a high shielding efficiency in the full frequency band range is achieved, effectively improving the shielding efficiency of the sensor and the measurement accuracy of the sensor. In summary, the 100 kA impulse large current sensing device based on multi-composite magnetic core materials is not only applicable to the measurement of impulse current waveforms, but also applicable to the design of steep current pulse sensors with shorter pulse widths and current measurement sensors with longer pulse widths, and has universality.

[0055] Example 2

[0056] A design method for a megakiloampere impulse large current sensing device based on multi-composite magnetic core materials, used to obtain the above-mentioned megakiloampere impulse large current sensing device based on multi-composite magnetic core materials, not limited to as Figure 6 shown, including:

[0057] S602, calculating the ampere-seconds of the measured current waveform according to the parameters of the measured current waveform;

[0058] S604, calculating the bandwidth requirement according to the frequency content of the measured current waveform;

[0059] S606, determining the proportion and superposition method of each material in the multi-composite magnetic core material according to the bandwidth requirement;

[0060] S608, determining the size of the composite magnetic core skeleton based on the ampere-seconds of the measured current waveform and the composite magnetic core material;

[0061] S610, conducting a magnetic saturation characteristic test on the magnetic core material to obtain the B-H curve data of the magnetic core material;

[0062] S612, determining the winding wire diameter, number of turns and number of segmented groups of the current winding coil with the sensitivity, upper cut-off frequency, lower cut-off frequency, winding resistance and heat generation of the current sensor as constraints;

[0063] S614, calculating the grouped induced voltage, inter-turn capacitance, equivalent inductance and capacitance to ground of the current winding coil, and conducting a rationality verification;

[0064] S616, when the rationality verification passes, determining the reliable operating range of the pulse current coil according to the parameters of the sensing device.

[0065] The design method for a megakiloampere impulse large current sensing device based on multi-composite magnetic core materials is not limited to determining the parameters of each part of the megakiloampere impulse large current sensing device based on multi-composite magnetic core materials, and the specific steps are not limited to as Figure 7 shown:

[0066] Determine the amplitude and parameters of the measured current waveform, and then determine the ampere-seconds of the measured current waveform and determine the upper and lower limits of the measured current waveform frequency; calculate the ampere-seconds of the measured current waveform according to the parameters of the measured current waveform. Ampere-seconds is an important indicator to measure the measurement ability of the pulse coil, indicating the product of the maximum measurement current that the coil can withstand and the pulse width.

[0067] Determine the proportion and superposition method of the composite magnetic core material; determine the proportion and superposition method of different magnetic core materials in the multi-composite magnetic core material according to the bandwidth requirement.

[0068] Determine the inner and outer diameters and height parameters of the composite magnetic core material; Based on the ampere-seconds of the current waveform to be measured and the determined composite magnetic core material, determine the inner and outer diameter dimensions and height of the magnetic core material.

[0069] Determine the B-H parameter curve of the wound magnetic core; Conduct a magnetic saturation characteristic test on the magnetic core material to obtain the B-H curve data of the magnetic core material.

[0070] Determine the winding cross-sectional dimensions, number of turns, and number of winding segments; Take the sensitivity, upper cut-off frequency, lower cut-off frequency, winding resistance, and heat generation of the current sensor as constraint conditions to preliminarily determine the wire diameter, number of turns, and number of winding segments.

[0071] Determine the shielding layer thickness parameter between the winding coil and the outer shell; Based on the insulation requirements and the requirements for the ground capacitance parameter, determine the shielding layer thickness parameter between the winding coil and the outer shell.

[0072] Determine the sensor transfer function, and determine the sensor transfer function based on the shielding layer thickness parameter between the winding coil and the outer shell and the winding cross-sectional dimensions, number of turns, and number of winding segments.

[0073] Calculate the exciting current value according to the sensor transfer function and determine whether it is saturated, and calculate parameters such as the capacitance, resistance, and inductance of the sensor winding to check whether the bandwidth meets the design requirements.

[0074] According to the design results, further check parameters such as the induced voltage of the coil winding, inter-turn capacitance, equivalent inductance, and ground capacitance to ensure the rationality of the design scheme. Determine the reliable operating range of the pulsed current coil according to the final parameter results of the design.

[0075] Example 3

[0076] Another aspect of the embodiments of the present invention also provides an electronic device for implementing the design method of the above-mentioned mega-kA impact large current sensing device based on multiple composite magnetic core materials. This electronic device is not limited to being a terminal device or a server in the system. The electronic device is not limited to including a memory and a processor. The memory stores a computer program, and the processor is configured to execute the steps in any one of the above method embodiments through the computer program.

[0077] Example 4

[0078] Another aspect of the embodiments of the present invention provides a computer program product or a computer program. The computer program product or the computer program includes computer instructions, and the computer instructions are stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the methods provided in various alternative embodiments of the above-mentioned design method of the mega-ampere impulse current sensing device based on a multi-composite magnetic core material. Among them, the computer program is configured to execute the steps in any one of the above method embodiments when running.

Claims

1. A hundred kA impulse large current sensing device based on a multi-composite magnetic core material, characterized in that, Comprising: A multi-composite magnetic core skeleton, a current winding coil, a parallel resistor, and a shielding housing; The multi-composite magnetic core skeleton is composed of at least two magnetic materials compounded. The current winding coil is distributed on the multi-composite magnetic core skeleton. Two ends of the parallel resistor are respectively connected to two ends of the current winding coil; The shielding housing is located outside the composite magnetic core skeleton; The current conductor to be measured axially penetrates the multi-composite magnetic core skeleton, and the measurement output end of the current winding coil is connected to an output circuit; The current winding coil is distributed on the multi-composite magnetic core skeleton in a segmented form with multiple turns in a group, and multiple groups of current winding coils are connected in series; A parallel resistor is connected in parallel at both ends of each group of current winding coils; The multi-composite magnetic core skeleton is composed of magnetic laminations of at least two materials pressed and compounded. The magnetic laminations of different materials have the same area and the thickness of each layer of magnetic lamination does not exceed 10 μm. The magnetic laminations of each material are uniformly symmetrically distributed axially on the multi-composite magnetic core skeleton; The shielding housing includes a low-frequency magnetic shielding housing, a high-frequency magnetic shielding housing, and an electrical shielding housing. The low-frequency magnetic shielding housing is used to shield low-frequency magnetic field interference signals within 1 MHz, and the high-frequency magnetic shielding housing is used to shield high-frequency magnetic field interference signals above 1 MHz.

2. The mega-kA impulse large current sensing device based on a multi-composite magnetic core material according to claim 1, characterized in that, The magnetic materials of the multi-composite magnetic core skeleton include: ferrite, microcrystalline alloy, permalloy.

3. The megakiloampere impulse high current sensing device based on a multi-composite magnetic core material according to claim 1, wherein Each layer of magnetic lamination is annular.

4. The large current sensing device with a hundred kA impact current based on a multi-composite magnetic core material as claimed in claim 1, wherein The high-frequency magnetic shielding housing is located between the low-frequency magnetic shielding housing and the electrical shielding housing, and the electrical shielding housing is located on the outermost layer.

5. The hundred kA impulse large current sensing device based on a multi-composite magnetic core material as claimed in claim 1, wherein The outer layer of the multi-composite magnetic core skeleton is wrapped with an insulating layer, and the outer layer of the current winding coil is wrapped with an insulating layer.

6. A design method for a megakiloampere impulse high current sensing device of a multi-composite magnetic core material, which is used to obtain the megakiloampere impulse high current sensing device based on the multi-composite magnetic core material according to any one of claims 1 to 5, characterized in that, Comprising: Calculating the ampere-second number of the current waveform to be measured according to the waveform parameters of the current to be measured; Calculating the bandwidth requirement according to the frequency content of the current waveform to be measured; Determining the proportion and stacking method of each material in the multi-composite magnetic core material according to the bandwidth requirement; Determining the size of the multi-composite magnetic core skeleton based on the ampere-second number of the current waveform to be measured and the multi-composite magnetic core material; Conducting a magnetic saturation characteristic test on the magnetic core material to obtain B-H curve data of the magnetic core material; Taking the sensitivity, upper cut-off frequency, lower cut-off frequency, winding resistance, and heat generation of the current sensing device as constraint conditions to determine the winding wire diameter, number of turns, and number of segmented groups of the current winding coil; Calculating the grouped induced voltage, inter-turn capacitance, equivalent inductance, and capacitance to ground of the current winding coil, and conducting a rationality verification; When the rationality verification is passed, determining the reliable working range of the pulse current coil according to the parameters of the current sensing device.

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