A large current measuring device and method based on lorentz force sensing

Abstract

The application discloses a large-current measuring device based on Lorentz force sensing, comprising a mechanical fixing mechanism, a current-carrying conductor mechanism fixed on one side of the mechanical fixing mechanism, the current-carrying conductor mechanism being used for connecting a current source to be measured and conducting a current to be measured, a magnetic field generating mechanism used for generating a magnetic field space with clear internal magnetic field space-time characteristics, the other side of the current-carrying conductor mechanism being arranged on the magnetic field generating mechanism and being arranged in the magnetic field space and generating Lorentz force under the action of the internal magnetic field of the magnetic field space, and a mechanical signal sensing mechanism arranged on the current-carrying conductor mechanism and used for sensing and measuring the Lorentz force borne by the current-carrying conductor mechanism, so as to inversely calculate the current value of the current to be measured. The device has the advantages of flexible adjustable calibration measurement range, linear controllable measurement uncertainty and wide applicability of measurement waveforms. The application further discloses a large-current measuring method based on Lorentz force sensing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of current measurement, more particularly, to a large current measurement device and method based on Lorentz force sensing. BACKGROUND

[0002] Large current measurement technology of kiloampere level and above is widely used in power systems, industrial production and scientific research, and has important scientific research significance and engineering practical value. In recent years, the voltage level and capacity of China's new power system have been greatly improved, and the devices and technologies in the field of national defense and military industry have developed rapidly, which puts forward higher requirements for the calibration range, accuracy and waveform applicability of large current measurement. Existing large current measurement technologies include:

[0003] (1) Current shunt technology based on Ohm's law, which measures the voltage drop across the resistor to inversely calculate the size of the measured current. This technology mainly applies shunt current transformer, disc shunt current transformer, coaxial shunt current transformer, and squirrel cage shunt current transformer. This technology mainly has the problems of limited maximum bandwidth caused by difficulty in suppressing parasitic inductance, and limited measurement range caused by difficulty in suppressing resistance body heating.

[0004] (2) Magnetic closed loop current transformer technology based on electromagnetic induction law, which measures the current of the secondary winding of the magnetic closed loop transformer to inversely calculate the size of the measured current of the primary winding. This technology mainly applies electronic compensation type current transformer, DBI type current transformer, and zero flux current transformer. This technology is only suitable for direct current and power frequency current measurement, and has the problems of significant magnetic leakage and core magnetic saturation when measuring current above 50 kA.

[0005] (3) Magnetic open loop current sensing technology based on Biot-Savart law, which measures the magnetic field near the bus to inversely calculate the size of the measured current. This technology mainly applies current measurement instrument based on magnetic sensing chip, Rogowski coil, and full current fiber-optic current transformer. This technology mainly has the problems of large stray electromagnetic field interference and high geometric position sensitivity, and the optical element also has the problem of low long-term reliability.

[0006] Therefore, the current large current measurement technology cannot meet the requirements of large current measurement range and high measurement accuracy, and some devices also have the problems of limited waveform applicability and low long-term reliability. This seriously hinders the scientific and technological development in the field of large current, and new large current measurement and sensing technology needs to be developed to meet the needs of national economic development and scientific and technological progress. SUMMARY

[0007] Therefore, the purpose of the present application is to provide a large current measurement device and method based on Lorentz force sensing, which aims to solve the problems in the prior art.

[0008] According to a first aspect of the present invention, a high-current measuring device based on Lorentz force sensing is provided, characterized in that it comprises:

[0009] Mechanical fixing mechanism;

[0010] A current-carrying conductor mechanism, one side of which is fixed to the mechanical fixing mechanism, is used to connect the current source to be measured and conduct the current to be measured.

[0011] A magnetic field generating mechanism is used to generate a magnetic field space with well-defined spatiotemporal characteristics of the internal magnetic field. The other side of the current-carrying conductor mechanism is disposed on the magnetic field generating mechanism and placed within the magnetic field space, and generates a Lorentz force under the action of the internal magnetic field of the magnetic field space.

[0012] A mechanical signal sensing mechanism is disposed on the current-carrying conductor mechanism to sense and measure the Lorentz force on the current-carrying conductor mechanism, thereby retrieving the current value of the current to be measured.

[0013] Preferably, the magnetic field generating mechanism includes:

[0014] Magnetic permeable unit;

[0015] The first magnetic pole unit and the second magnetic pole unit are arranged opposite each other within the magnetically conductive unit at a predetermined distance from each other, forming the two poles of the magnetic field.

[0016] Preferably, the first magnetic pole unit and the second magnetic pole unit each comprise:

[0017] The main magnet has its first surface disposed on the magnetically conductive unit;

[0018] A magnetic field configuration controller is used to regulate the spatial characteristics of a magnetic field space. It includes a shimming plate, a pole shoe, and a shimming sheet. The shimming plate is disposed on the second surface of the main magnet, the pole shoe is disposed on the shimming plate, the main magnet, the shimming plate, and the pole shoe form a stacked structure, and the shimming sheet is disposed on the shimming plate and surrounds the pole shoe.

[0019] A magnetic field stabilizer, used to ensure the stability of the temporal characteristics of the magnetic field space, includes a supplementary magnet and a connector. The supplementary magnet is wound around the outer periphery of the main magnet and connected to the magnetic conductive unit via the connector.

[0020] Preferably, the shimming plate is a cuboid or a cylinder, and there are multiple such plates;

[0021] The uniformity of the internal magnetic field can be adjusted by changing the number and position of the shimming plates.

[0022] Preferably, the magnetically conductive unit includes an end face yoke pair and a plurality of support yokes, wherein the end face yoke pair includes an upper end face yoke and a lower end face yoke that are parallel to each other and spaced apart by a preset distance.

[0023] The end face yoke pair has multiple connecting ends, and the multiple support yokes are detachably connected to the corresponding connecting ends, thereby forming a magnetic circuit between the end face yoke pair and the multiple support yokes.

[0024] Preferably, at least one of the support yokes is connected to a corresponding connection end, and the strength of the internal magnetic field can be adjusted by regulating the number of connections of the support yokes.

[0025] Preferably, the current-carrying conductor mechanism includes a current-carrying conductor lead segment, a current-carrying conductor transition segment, and a current-carrying conductor test segment;

[0026] Two current-carrying conductor lead segments are arranged parallel to each other at a predetermined distance. Each current-carrying conductor lead segment is vertically connected to a current-carrying conductor transition segment. The current-carrying conductor lead segment and the corresponding current-carrying conductor transition segment form an L-shaped structure. The two current-carrying conductor transition segments are connected through the current-carrying conductor test segment.

[0027] The current-carrying conductor transition section is used to achieve a soft mechanical connection with the current-carrying conductor test section. Its width is smaller than that of the current-carrying conductor lead section and the current-carrying conductor test section. The current-carrying conductor test section is a plate-shaped structure with a preset width.

[0028] Preferably, the current-carrying conductor test segment is fixed to the mechanical fixing mechanism by the test segment reinforcement layer, and the mechanical signal sensing mechanism is sandwiched between the current-carrying conductor test segment and the test segment reinforcement layer. The mechanical signal sensing mechanism is used to sense and measure the Lorentz force on the current-carrying conductor test segment.

[0029] According to a second aspect of the present invention, a method for measuring large current based on Lorentz force sensing is provided, characterized in that it includes:

[0030] A magnetic field space with clearly defined spatiotemporal characteristics that generates an internal magnetic field.

[0031] The current to be measured is conducted to the magnetic field space, and a Lorentz force is generated under the action of the internal magnetic field of the magnetic field space.

[0032] The Lorentz force is sensed and measured to deduce the current value of the current to be measured.

[0033] Preferably, the current value of the current to be measured is obtained by the following formula:

[0034]

[0035] in, The Lorentz force experienced by a current-carrying conductor mechanism carrying the current to be measured within a magnetic field space;

[0036] B is the magnetic field strength of the internal magnetic field, and its value is known and fixed.

[0037] L is the length of the current-carrying conductor test section of the current-carrying conductor mechanism carrying the current to be measured, and is known to be fixed;

[0038] S is the effective area of ​​the mechanical signal sensing mechanism, which is known to be fixed.

[0039] For the sensing items of the mechanical signal sensing mechanism;

[0040] I represents the current to be measured, and represents the term to be measured.

[0041] The large current measurement device and method based on Lorentz force sensing in this application have the following advantages compared with the prior art:

[0042] 1. Flexible and Adjustable Calibration Measurement Range: The calibration current measurement range of the device and method of the present invention can be adjusted by changing the spatiotemporal characteristics of the magnetic field inside the magnetic field space or by changing the effective area of ​​the mechanical signal sensing mechanism. Taking the change of the spatiotemporal characteristics of the magnetic field inside the magnetic field space as an example, the product of the peak value of the measured current and the peak value of the magnetic field is kept within a small range, that is, within a preset amplitude (the Lorentz force is positively correlated with the peak value of the current and the peak value of the magnetic field. If the current increases, the magnetic field strength should be appropriately reduced. At this time, a preset number of support yokes can be removed and the number and position of the shimming plates can be adjusted to achieve the product changing within a small range. When the current decreases, the reverse reasoning is used, which will not be elaborated here). That is, the Lorentz force on the current-carrying conductor mechanism is kept within a small range, so that the measurement uncertainty of the device can be completely decoupled from the peak value of the measured current. Therefore, the device and method of the present invention can flexibly adjust the calibration current measurement range while ensuring measurement accuracy.

[0043] 2. Linear and Controllable Measurement Uncertainty: The measurement uncertainty of the device and method of the present invention includes the spatiotemporal characteristic uncertainty of the magnetic field within the magnetic field space, the spatial uncertainty of the direction of the measured current, and the measurement uncertainty of the mechanical signal, which are unrelated to the conductor temperature and current density distribution. Specifically, the spatiotemporal characteristic uncertainty of the magnetic field is only related to the structure of the magnetic field generating mechanism and is a fixed value; the spatial uncertainty of the direction of the measured current is only related to the spatial position of the current-carrying conductor device and is a fixed value; the measurement uncertainty of the mechanical signal is only related to the mechanical signal sensing mechanism and is affected by the signal amplitude. By changing the magnitude of the spatial magnetic field, it can be controlled to a fixed value or within a linearly related range. Therefore, the uncertainty involved in the device and method of the present invention is linearly controllable, ensuring high accuracy in current measurement.

[0044] 3. Wide applicability of measurement waveforms: The device and method of the present invention are based on Ampere's law of force, which converts the measured object from a current signal into a mechanical signal; since the mechanical sensor is small in size, steady-state and transient mechanical sensors can be simultaneously embedded in the mechanical signal sensing mechanism, so that the device has the ability to measure both steady-state and transient currents at the same time; therefore, the method and device of the present invention can use the same equipment to simultaneously meet the high-precision measurement requirements of DC, power frequency and transient current, and the measurement waveforms are widely applicable. Attached Figure Description

[0045] The above and other objects, features and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings.

[0046] Figures 1-3 Schematic diagrams of a high-current measurement device based on Lorentz force sensing according to an embodiment of the present invention are shown from different perspectives.

[0047] Figure 4 A schematic diagram of the mechanical fixing mechanism according to an embodiment of the present invention is shown.

[0048] Figure 5 A schematic diagram of the connecting flange according to an embodiment of the present invention is shown.

[0049] Figure 6 A schematic diagram of the structure of a current-carrying conductor mechanism according to an embodiment of the present invention is shown.

[0050] Figure 7 A schematic diagram of the connection structure of the mechanical fixing mechanism and the current-carrying conductor mechanism according to an embodiment of the present invention is shown.

[0051] Figure 8 A schematic diagram illustrating the principle of an embodiment of the present invention is shown.

[0052] Figure 9 A schematic diagram of a magnetic field generating mechanism according to an embodiment of the present invention is shown.

[0053] Figure 10 A cross-sectional structural schematic diagram of a magnetic field generating mechanism according to an embodiment of the present invention is shown.

[0054] Figures 11-12 Schematic diagrams of the permanent magnet positioning flange according to embodiments of the present invention are shown from different perspectives.

[0055] In the diagram: Mechanical fixing mechanism 1, inertial constraint component 11, connecting unit 12, connecting flange 121, connecting panel 122, connecting flange 121, flange disc 124, beam 123, current-carrying conductor mechanism 2, current-carrying conductor lead segment 21, current-carrying conductor transition segment 22, current-carrying conductor test segment 23, magnetic field generating mechanism 3, main magnet 31, shimming plate 321, pole shoe 322, supplementary magnet 33, upper end face yoke 3411, lower end face yoke 3412, support yoke 342, yoke connector 343, balancing flange 344, permanent magnet positioning flange 345, mechanical signal sensing mechanism 4, lead segment reinforcement layer 51, lead segment clamping flange 52, test segment clamping flange 61, test segment reinforcement layer 62. Detailed Implementation

[0056] Various embodiments of the invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by the same or similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale.

[0057] like Figures 1 to 3 As shown, this invention provides a high-current measurement device based on Lorentz force sensing, comprising a mechanical fixing mechanism 1, a current-carrying conductor mechanism 2, a magnetic field generating mechanism 3, and a mechanical signal sensing mechanism 4. The current-carrying conductor mechanism 2 is fixed on one side of the mechanical fixing mechanism 1 and is used to connect to the current source to be measured and conduct the current to be measured. The magnetic field generating mechanism 3 is used to generate a magnetic field space with clearly defined spatiotemporal characteristics. The other side of the current-carrying conductor mechanism 2 is disposed on the magnetic field generating mechanism 3, placed within the magnetic field space, and generates a Lorentz force under the action of the internal magnetic field of the magnetic field space. The mechanical signal sensing mechanism 4 is disposed on the current-carrying conductor mechanism 2 and is used to sense and measure the Lorentz force acting on the current-carrying conductor mechanism 2, thereby retrieving the current value of the current to be measured.

[0058] refer to Figure 4 The mechanical fixing mechanism 1 includes an inertial constraint member 11 and a connecting unit 12. There are two inertial constraint members 11, which are set at a preset distance from each other. The connecting unit 12 includes a connecting flange 121, a connecting panel 122 and a beam 123. The connecting panel 122 is connected to the inertial constraint member 11 through the connecting flange 121, and the beam 123 is connected to the connecting panel 122.

[0059] Specifically, four connecting panels 122 are provided, with each inertial constraint member 11 corresponding to a connecting panel 122. Each connecting panel 122 is connected to the inertial constraint member 11 via a connecting flange 121 and a flange disc 124. The beam body 123 includes interconnected crossbeams and longitudinal beams. The longitudinal beams are bolted to the connecting panels 122, and the crossbeams are bolted to the longitudinal beams. In this embodiment, the beam body 123, connecting flanges 121, flange discs 124, and connecting panels 122 are all made of A70 stainless steel, and each inertial constraint member 11 weighs 0.5 tons.

[0060] In this embodiment, the mechanical fixing mechanism has a good overall elastic modulus. Preferably, the overall elastic modulus of the mechanical fixing mechanism is greater than 20 GPa.

[0061] refer to Figure 6 The current-carrying conductor mechanism 2 includes a current-carrying conductor lead segment 21, a current-carrying conductor transition segment 22, and a current-carrying conductor test segment 23. Two current-carrying conductor lead segments 21 are arranged parallel to each other at a predetermined distance. Each current-carrying conductor lead segment 21 is vertically connected to a current-carrying conductor transition segment 22, forming an L-shaped structure. The two current-carrying conductor transition segments 22 are connected via the current-carrying conductor test segment 23. The current-carrying conductor transition segment 22 is used to achieve a soft mechanical connection with the current-carrying conductor test segment 23, and its width is smaller than the widths of the current-carrying conductor lead segment 21 and the current-carrying conductor test segment 23. The current-carrying conductor test segment 23 is a plate-shaped structure with a predetermined width.

[0062] The current-carrying conductor test segment 23 is fixed to the mechanical fixing mechanism 1 by the test segment reinforcement layer 62. The mechanical signal sensing mechanism 4 is sandwiched between the current-carrying conductor test segment 23 and the test segment reinforcement layer 62. The mechanical signal sensing mechanism 4 is used to sense and measure the Lorentz force experienced by the current-carrying conductor test segment 23. In this embodiment, as... Figure 8 As shown by the dashed lines within the transparent portion, the mechanical signal sensing mechanism 4 is a mechanical sensor matrix.

[0063] like Figure 6 As shown, specifically, the current-carrying conductor lead segment 21 of the current-carrying conductor mechanism 2 is perpendicularly arranged to the current-carrying conductor transition segment 22. The current-carrying conductor transition segment 22 includes connectors at both ends and a flexible connecting part in the middle. The connectors at both ends are plate-like structures, and the flexible connecting part in the middle is a filament with a small cross-section, used to achieve a soft mechanical connection and a strong electrical connection with the current-carrying conductor test segment 23. The current-carrying conductor test segment 23 is perpendicularly arranged to the current-carrying conductor transition segment 22. This structural design of the current-carrying conductor mechanism 2 makes the current-carrying conductor test segment 23 more sensitive to the Lorentz force. In this embodiment, each segment of the current-carrying conductor mechanism 2 is a copper-based conductor.

[0064] The current-carrying conductor mechanism 2 can conduct a large current with a peak value greater than 0.1 kA, provided that the temperature rise of the mechanism is less than 300 K. Preferably, the current-carrying conductor mechanism can continuously conduct a large DC current, a large power frequency current, or a wide-frequency current with a peak value greater than 0.1 kA for a period of not less than 1 s, or conduct a large impulse current with a peak value greater than 1 kA at least once within a period of not less than 1 s, provided that the temperature rise of the mechanism is less than 300 K. The conductor length of the current-carrying conductor mechanism 2 placed in the magnetic field space is not less than 1 mm, and the direction of current conduction by the current-carrying conductor mechanism 2 in the magnetic field space is not parallel to the direction of the magnetic field.

[0065] The current-carrying conductor structure is composed of multiple segments of conductors with different conductivity. Preferably, the conductivity of the conductors is 10%-120% according to the international standard for annealed copper.

[0066] The mechanical fixing mechanism 1 is connected to the current-carrying conductor mechanism 2 and the mechanical signal sensing mechanism 4, which can make the overall and local deformation of the high current measuring device based on Lorentz force sensing less than 20 mm.

[0067] like Figure 7 As shown in the figure, only the crossbeam and longitudinal beam of the mechanical fixing mechanism 1 are shown. The current-carrying conductor mechanism 2 and the mechanical fixing mechanism 1 are fixed together by a reinforcing layer through a clamping flange. After the current-carrying conductor lead segment 21 is tightly attached to the longitudinal beam by the lead segment clamping flange 52, HS ZYLON fiber is wound along the Z-axis in the XY plane and coated with epoxy resin Stycast W19 / Cat11 to form the lead segment reinforcing layer 51, thereby achieving segmented fixing of the current-carrying conductor lead segment 21. In this embodiment, there are two segments. After the current-carrying conductor test segment 23 is tightly attached to the crossbeam by the test segment clamping flange 61, HS ZYLON fiber is wound along the X-axis in the YZ plane and coated with epoxy resin Stycast W19 / Cat11 to form the test segment reinforcing layer 62, thereby achieving fixing of the current-carrying conductor test segment 23. The mechanical sensor matrix, constituting the mechanical signal sensing mechanism 4 (not shown in the figure), is located between the outer surface of the current-carrying conductor test section 23 in the positive Y-axis direction and the inner surface of the test section reinforcement layer 62.

[0068] The portion of the mechanical fixing mechanism 1 that contacts the current-carrying conductor mechanism 2 has good electrical insulation properties. Preferably, the conductivity of the portion of the mechanical fixing mechanism that contacts the current-carrying conductor mechanism is less than 10. 7 S / m.

[0069] The mechanical signal sensing mechanism 4 can realize stress or strain measurement at one or more points of the current-carrying conductor mechanism 2. Preferably, the mechanical signal sensing mechanism 4 is a sensing matrix composed of pressure sensors, and the matrix size is from 1×1 to 100×100.

[0070] In this embodiment, since the mechanical signal sensing mechanism 4 is small in size, both steady-state and transient mechanical sensors are embedded in the mechanical signal sensing mechanism 4, enabling the device to measure both steady-state and transient currents simultaneously.

[0071] refer to Figures 9-10 The magnetic field generating mechanism 3 includes: a magnetically conductive unit; a first magnetic pole unit and a second magnetic pole unit, which are disposed opposite each other within the magnetically conductive unit at a predetermined distance to form the two poles of a magnetic field. In this embodiment, the second magnetic pole unit is located at a predetermined distance from the first magnetic pole unit, and the two are coaxially arranged to form a uniform magnetic field space.

[0072] The first magnetic pole unit and the second magnetic pole unit each include: a main magnet 31, the first surface of which is disposed on the magnetically conductive unit; a magnetic field configuration regulator for regulating the spatial characteristics of the magnetic field space, including a shimming plate 321, a pole shoe 322, and a shimming plate, wherein the shimming plate 321 is disposed on the second surface of the main magnet 31, the pole shoe 322 is disposed on the shimming plate 321, the main magnet 31, the shimming plate 321, and the pole shoe 322 form a stacked structure, and the shimming plate is disposed on the shimming plate 321 and surrounds the pole shoe 322; and a magnetic field stabilizer for ensuring the stability of the temporal characteristics of the magnetic field space, including a supplementary magnet 33 and a connector, wherein the supplementary magnet 33 is wound around the outer periphery of the main magnet 31 and connected to the magnetically conductive unit via the connector.

[0073] In this embodiment, the main magnet 31 is a samarium cobalt permanent magnet, and the pole piece 322 has a ring structure. The main magnet 31, the shimming plate 321, the pole piece 322, and the shimming plates are all made of magnetic materials. The shimming plate 321 is adsorbed onto the main magnet 31, the pole piece 322 is adsorbed onto the shimming plate 321, and multiple shimming plates are adsorbed onto the side of the shimming plate 321 away from the main magnet 31 and located circumferentially inside the ring structure of the pole piece 322. The shimming plates are cuboids or cylinders, and there are multiple of them. By adjusting the number and position of the shimming plates, the uniformity of the internal magnetic field can be adjusted, thereby achieving fine-tuning of the magnetic field strength. Depending on the magnitude of the current to be measured, the adjustment of the number and position of the shimming plates is coordinated with the adjustment of the number of the support yoke 342, thereby collaboratively adjusting the magnetic field strength in the magnetic field space.

[0074] The magnetically conductive unit includes an end face yoke pair and multiple support yokes 342. The end face yoke pair includes an upper end face yoke 3411 and a lower end face yoke 3412 that are parallel to each other and spaced apart by a preset distance. The end face yoke pair has multiple connecting ends, and the multiple support yokes 342 are detachably connected to the corresponding connecting ends via yoke connectors 343, thereby forming a magnetically conductive circuit between the end face yoke pair and the multiple support yokes 342.

[0075] At least one of the bracket yokes 342 is connected to a corresponding connection end. By adjusting the number of bracket yokes 342 connected, the strength of the internal magnetic field can be adjusted.

[0076] In this embodiment, the main magnet 31 is a samarium cobalt permanent magnet main magnet 31, which generates a fixed magnetic field and is composed of multiple permanent magnet blocks. The main magnet 31 will demagnetize after long-term operation, and the supplementary magnet 33 will replenish the magnetism. The end face yoke and the support yoke 342 are both made of Q235 material, and the two are connected by eight yoke connectors 343 to form the magnetic conduction circuit of this embodiment; the field homogenizing plate 321 and pole shoe 322, which are made of industrial pure iron, and the samarium cobalt field homogenizing plate (not shown in the figure, placed on the surface of the field homogenizing plate 321 facing another magnetic pole unit) constitute the magnetic field configuration regulator of this embodiment, which improves the magnetic field uniformity of the magnetic field space; the supplementary magnet 33 is fixed to the end face yoke by sixteen bolts and serves as the magnetic field stabilizer of this embodiment; and the balancing flange 344.

[0077] The magnetic circuit is designed to reduce magnetic reluctance and enhance magnetic field strength. The shimming plate 321 is used to mitigate the impact of uneven surfaces on the multiple permanent magnet blocks of the main magnet 31. The pole shoe 322 is used to reduce edge effects on the main magnet 31. Samarium cobalt shimming plates are located on the lower surface of the pole shoe 322, in an inner groove (not shown in the figure), and in contact with the surface. The shimming plates are small cuboids or cylinders located inside the pole shoe 322 and adhered to its lower surface. The number and distribution of the shimming plates need to be determined based on the actual processing of the magnetic field generating mechanism 3.

[0078] The magnetic field generating mechanism 3 also includes a balancing flange 344 and a permanent magnet positioning flange 345. The balancing flange 344 is located at the bottom of the magnetic conductive unit and is used to match the Z-axis position of the magnetic field generating mechanism 3 and the mechanical positioning mechanism. The permanent magnet positioning flange 345 is located at the top of the lower first magnetic pole unit. The bottom surface of the permanent magnet positioning flange 345 has a fixing groove and the top surface has a positioning groove. The permanent magnet positioning flange 345 is fixed to the top of the first magnetic pole unit through its fixing groove. Specifically, the permanent magnet positioning flange 345 is nested on the pole shoe 322 of the lower first magnetic pole unit through its fixing groove. The positioning groove is a groove-shaped structure with a notch on one side. The end of the test section reinforcement layer 62 that is away from the beam 123 is tightly fitted into the positioning groove, thereby realizing the positioning of the test section reinforcement layer 62.

[0079] In this embodiment, the magnetic field generating mechanism 3 can generate a volume of not less than 9 A magnetic field space with an internal magnetic field peak greater than 1 mT. Preferably, the magnetic field generating mechanism can generate a volume of not less than 9 mT. The magnetic field has a peak value greater than 1 mT and a spatial uniformity better than 5000 ppm. More preferably, the magnetic field generating mechanism 3 can generate a magnetic field space with a volume of not less than 9... The magnetic field space has an internal magnetic field peak value greater than 1 mT, an internal magnetic field spatial uniformity better than 5000 ppm, and an internal magnetic field temporal uniformity better than 1000 ppm.

[0080] The high-current measurement device based on Lorentz force sensing in this embodiment can be used with reference to the following steps:

[0081] 1. First, adjust the spatiotemporal characteristics of the magnetic field generating mechanism 3 as needed, specifically the current to be measured. Specifically, remove the corresponding iron yoke connector 343 and remove the preset number of support iron yokes 342. This will allow the magnetic field strength in the magnetic field space to be adjusted by 1 to 3 times, thereby adjusting the time characteristics of the internal magnetic field of the magnetic field space. Adjusting the number and position of the shimming plates will allow the spatial characteristics of the internal magnetic field of the magnetic field space to be adjusted.

[0082] 2. Connect the current-carrying conductor lead segment 21 of the current-carrying conductor mechanism 2 to the current source to be measured, and connect the mechanical signal sensing mechanism 4 to the processor;

[0083] 3. When the current source to be measured is turned on, the processor receives the sensing term σ from the mechanical signal sensing mechanism 4 and calculates the current value to be measured according to the following formula.

[0084] This invention also discloses a method for measuring large currents based on Lorentz force sensing, which includes:

[0085] S1) Generates a magnetic field space with clearly defined spatiotemporal characteristics of its internal magnetic field;

[0086] S2) The current to be measured is conducted to the magnetic field space, and Lorentz force is generated under the action of the internal magnetic field of the magnetic field space;

[0087] S3) Sensing and measuring the Lorentz force, thereby retrieving the current value of the current to be measured.

[0088] Referring to the diagram, the current value to be measured can be derived using the following formula:

[0089]

[0090] in, The Lorentz force experienced by the current-carrying conductor mechanism 2, which carries the current to be measured, within the magnetic field space;

[0091] B is the magnetic field strength of the internal magnetic field, and its value is known and fixed.

[0092] L is the length of the current-carrying conductor test section of the current-carrying conductor mechanism carrying the current to be measured, and is known to be fixed;

[0093] S is the effective area of ​​the mechanical signal sensing mechanism, which is known to be fixed.

[0094] For the sensing items of the mechanical signal sensing mechanism;

[0095] I represents the current to be measured, and represents the term to be measured.

[0096] It should be noted that once the magnetic field strength is adjusted, the value of the internal magnetic field strength B is known and fixed.

[0097] The technical solution in this application differs from the prior art mainly in the following ways:

[0098] 1. Different Current Inversion Methods: The technical solution proposed in this invention is based on Ampere's law, inverting the large current to be measured by measuring the Lorentz force acting on the current-carrying conductor mechanism 2; while existing technologies are based on Ohm's law, the law of electromagnetic induction, and the Biot-Savart law, performing current inversion through the voltage or magnetic field generated by the current to be measured. Therefore, the current inversion methods of existing technologies are significantly different from this solution;

[0099] 2. Different mechanisms for determining the calibration measurement range: In the technical solution proposed in this invention, the calibration measurement range depends not only on the mechanical structure of the device itself and the peak value of the current to be measured, but also on the spatiotemporal characteristics of the magnetic field within the magnetic field space; while the measurement range of existing sensing mechanisms depends only on the mechanical structure of the device itself and the peak value of the current to be measured. Therefore, the mechanism for determining the calibration measurement range of existing technologies differs significantly from that of this solution.

[0100] 3. Different synthesis mechanisms for measurement uncertainties: In the technical solution proposed in this invention, the measurement uncertainty includes the spatiotemporal characteristic uncertainty of the magnetic field inside the magnetic field space, the spatial uncertainty of the direction of the current to be measured, and the measurement uncertainty of the sensing mechanism; while the measurement uncertainty of the prior art, in addition to the above, also includes temperature uncertainty caused by conductor thermal effect, current density distribution uncertainty caused by eddy current effect, etc.; at the same time, the magnetic field of the prior art is only generated by the current to be measured, while the proposed solution is also generated by the magnetic field generating mechanism 3, and the nature of the source of the spatiotemporal characteristic uncertainty of the magnetic field is also completely different; therefore, the measurement uncertainty synthesis mechanism of the prior art is significantly different from that of this solution.

[0101] The large current measurement device and method based on Lorentz force sensing in this application have the following advantages compared with the prior art:

[0102] 1. Flexible and Adjustable Calibration Measurement Range: The calibration current measurement range of the device and method of the present invention can be adjusted by changing the spatiotemporal characteristics of the magnetic field inside the magnetic field space; keeping the product of the peak value of the measured current and the peak value of the magnetic field within a small interval, i.e., within a preset amplitude (Lorentz force is positively correlated with the peak value of the current and the peak value of the magnetic field. If the current increases, the magnetic field strength should be appropriately reduced. At this time, a preset number of support yokes 342 can be removed and the number and position of the shimming plates can be adjusted to achieve the product changing within a small interval. When the current decreases, the reverse reasoning is used, which will not be elaborated here). That is, keeping the Lorentz force on the current-carrying conductor mechanism 2 changing within a small interval, the measurement uncertainty of the device can be completely decoupled from the peak value of the measured current. Therefore, the device and method of the present invention can flexibly adjust the calibration current measurement range while ensuring measurement accuracy.

[0103] 2. Linear and Controllable Measurement Uncertainty: The measurement uncertainty of the device and method of the present invention includes the spatiotemporal characteristic uncertainty of the magnetic field inside the magnetic field space, the spatial uncertainty of the direction of the current to be measured, and the measurement uncertainty of the mechanical signal, which are unrelated to the conductor temperature and current density distribution. Among them, the spatiotemporal characteristic uncertainty of the magnetic field is only related to the structure of the magnetic field generating mechanism 3 and is a fixed value; the spatial uncertainty of the direction of the current to be measured is only related to the spatial position of the current-carrying conductor device and is a fixed value; the measurement uncertainty of the mechanical signal is only related to the mechanical signal sensing mechanism 4 and is affected by the signal amplitude. By changing the magnitude of the spatial magnetic field, it can be controlled to a fixed value or within a linear range related to the amplitude. Therefore, the uncertainty involved in the device and method of the present invention is linearly controllable, which can ensure high accuracy measurement of current.

[0104] 3. Wide applicability of measurement waveforms: The device and method of the present invention are based on Ampere's law of force, which converts the measured object from a current signal into a mechanical signal; and since the mechanical sensor is small in size, steady-state and transient mechanical sensors can be simultaneously embedded in the mechanical signal sensing mechanism 4, so that the device has the ability to measure both steady-state and transient currents at the same time; therefore, the method and device of the present invention can use the same equipment to simultaneously meet the high-precision measurement requirements of DC, power frequency and transient current, and the measurement waveforms are widely applicable.

[0105] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0106] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A large current flow measuring device based on Lorentz force sensing, characterized by, The application relates to a current sensor, which comprises the following parts: a mechanical fixing mechanism; a current-carrying conductor mechanism, which is fixed on one side of the mechanical fixing mechanism and is used for connecting a current source to be measured and conducting a current to be measured; the current-carrying conductor mechanism comprises a current-carrying conductor lead segment, a current-carrying conductor transition segment and a current-carrying conductor test segment; two current-carrying conductor lead segments are arranged in parallel at a preset distance apart from each other, and the current-carrying conductor transition segment is vertically connected to each current-carrying conductor lead segment; the current-carrying conductor lead segment and the corresponding current-carrying conductor transition segment form an L-shaped structure, and the two current-carrying conductor transition segments are connected through the current-carrying conductor test segment; the current-carrying conductor transition segment is used for realizing a soft mechanical connection with the current-carrying conductor test segment, and the width of the current-carrying conductor transition segment is smaller than the width of the current-carrying conductor lead segment and the current-carrying conductor test segment; the current-carrying conductor test segment is a plate-shaped structure with a preset width; a magnetic field generating mechanism is used for generating a magnetic field space with clear internal magnetic field space characteristics; the other side of the current-carrying conductor mechanism is arranged on the magnetic field generating mechanism and is placed in the magnetic field space and generates Lorentz force under the action of the internal magnetic field of the magnetic field space; a mechanical signal sensing mechanism is arranged on the current-carrying conductor mechanism and is used for sensing and measuring the Lorentz force borne by the current-carrying conductor mechanism, so as to inversely calculate the current value of the current to be measured; the current-carrying conductor test segment is fixed to the mechanical fixing mechanism through a test segment reinforcing layer; the mechanical signal sensing mechanism is arranged between the current-carrying conductor test segment and the test segment reinforcing layer and is used for sensing and measuring the Lorentz force borne by the current-carrying conductor test segment; the mechanical fixing mechanism comprises a cross beam and a longitudinal beam; the current-carrying conductor mechanism and the mechanical fixing mechanism are fixed through a reinforcing layer; the current-carrying conductor lead segment is tightly attached to the longitudinal beam through a lead segment clamping flange, is wound with fibers and is coated with epoxy resin to form a lead segment reinforcing layer, thereby realizing the segmented fixing of the current-carrying conductor lead segment; the current-carrying conductor test segment is tightly attached to the cross beam through a test segment clamping flange, is wound with fibers and is coated with epoxy resin to form a test segment reinforcing layer, thereby realizing the fixing of the current-carrying conductor test segment; the magnetic field generating mechanism comprises a permanent magnet positioning flange; a positioning groove is arranged on the top surface of the permanent magnet positioning flange; the positioning groove is a groove-shaped structure with a notch on one side; one end of the test segment reinforcing layer, which is away from the beam body, is tightly attached to the positioning groove, thereby realizing the positioning of the test segment reinforcing layer.

2. The large current sensing device based on Lorentz force sensing according to claim 1, characterized in that, The magnetic field generating mechanism comprises: a magnetic conductive unit; a first magnetic pole unit and a second magnetic pole unit, which are oppositely arranged in the magnetic conductive unit at a preset distance apart from each other and form two poles of a magnetic field.

3. The large current sensing device based on Lorentz force sensing according to claim 2, characterized in that, The first magnetic pole unit and the second magnetic pole unit respectively comprise: a main magnet, whose first surface is arranged on the magnetic conductive unit; a magnetic field configuration regulator, which is used for regulating the space characteristics of a magnetic field space and comprises a shimming plate, a pole shoe and a shimming sheet; the shimming plate is arranged on the second surface of the main magnet; the pole shoe is arranged on the shimming plate; the main magnet, the shimming plate and the pole shoe form a laminated structure; and the shimming sheet is arranged on the shimming plate and is arranged around the pole shoe. The magnetic field stabilizer for ensuring the time characteristic stability of the magnetic field space comprises a supplementary magnet and a connecting member, the supplementary magnet is arranged around the outer periphery of the main magnet and is connected to the magnetic conducting unit through the connecting member.

4. The large current sensing device based on Lorentz force sensing according to claim 3, characterized in that, The field uniformity pieces are cuboids or cylinders, and the number of the field uniformity pieces is multiple; The uniformity of the internal magnetic field can be adjusted by adjusting the number and position of the field uniformity pieces.

5. The large current sensing device based on Lorentz force sensing according to claim 2, characterized in that, The magnetic conducting unit comprises an end face yoke pair and a plurality of support yokes, the end face yoke pair comprises an upper end face yoke and a lower end face yoke which are parallel to each other and are arranged at a preset distance apart; The end face yoke pair has a plurality of connecting end heads, and the plurality of support yokes are respectively detachably connected to the corresponding connecting end heads, so that the magnetic conducting loop is formed between the end face yoke pair and the plurality of support yokes.

6. The large current sensing device based on Lorentz force sensing according to claim 5, characterized in that, At least one of the support yokes is connected to the corresponding connecting end head, and the intensity of the internal magnetic field can be adjusted by adjusting the number of the support yokes connected to the corresponding connecting end head.

7. A method of measuring a large current flow based on Lorentz force perception, using the device for measuring a large current flow based on Lorentz force perception according to any one of claims 1-6, characterized in that, The magnetic field space with clear time and space characteristics of the internal magnetic field is generated; The current to be measured is conducted to the magnetic field space, and the Lorentz force is generated under the action of the internal magnetic field of the magnetic field space; The Lorentz force is sensed and measured, so as to inverse the current value of the current to be measured.

8. The large current measurement method based on the sensing of the Lorentz force according to claim 7, wherein the current value of the current to be measured is inverted by the following formula: B is the magnetic field intensity of the internal magnetic field, which is fixed and known; wherein the Lorentz force experienced by a current-carrying conductor mechanism in the magnetic field space for a through-flow of a current to be measured; L is the length of the current-carrying conductor test section of the current-carrying conductor mechanism through which the current to be measured flows, which is fixed and known; S is the effective area of the mechanical signal sensing mechanism, which is fixed and known; I is the current to be measured, which is the item to be measured. a sensing item for a mechanical signal sensing mechanism; ​

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