Current transformer high-voltage side structure based on quantum precision magnetic measurement

Abstract

The utility model provides a high-voltage side structure of a current transformer based on quantum precision magnetic measurement. The high-voltage side structure of the current transformer comprises a shell; the primary winding is arranged in the shell, the two ends of the primary winding extend out of the shell, and the primary winding is sleeved with an iron core; the secondary winding is wound on the iron core; and the nitrogen vacancy color center magnetic sensing head is arranged at the opening groove. According to the utility model, primary magnetic flux is generated on the iron core through the primary winding; a secondary winding on the iron core is connected to the iron core to generate secondary magnetic flux opposite to the primary magnetic flux in direction; the size of the magnetic field of the combined magnetic flux of the primary magnetic flux and the secondary magnetic flux at the opening groove is detected through the nitrogen vacancy color center magnetic sensing head, the current of the secondary loop is controlled, the magnetic field of the combined magnetic flux of the primary magnetic flux and the secondary magnetic flux at the opening groove is zero, and then the magnetic field of the combined magnetic flux of the primary magnetic flux and the secondary magnetic flux at the opening groove is calculated based on the current of the secondary loop in the state. And obtaining the size of the primary loop current according to the calculated transformation ratio.

Description

Technical Field

[0001] The utility model relates to the technical field of current transformers, and more specifically, to a high-voltage side structure of a current transformer based on quantum precision magnetic measurement. Background Art

[0002] Due to limitations such as narrow measurement bandwidth, small dynamic range, and analog output, traditional electromagnetic transformers are difficult to meet the development requirements of smart grids. As the voltage level continues to increase, the insulation and structure of transformers become more complex. Correspondingly, their volume and weight also increase significantly, directly increasing the difficulties for workers in transportation, installation, commissioning, and maintenance. The production and use costs also increase geometrically with the increase in voltage level. Electronic transformers have the advantages of simple insulation structure, no magnetic saturation and ferromagnetic resonance, large transient response range, light weight, small volume, and digital output signal, and can adapt to the development direction of smart grids. They have been increasingly applied to various automated substations. Applying electronic current transformers to electrical complete equipment has comprehensively improved the intelligence level of products and greatly accelerated the pace of intelligent construction. However, during the pilot stage of smart substations of the State Grid Corporation, electronic current transformers have problems such as anti-interference problems of electronic devices and optical devices, temperature problems, and integration drift. The accuracy and stability problems have become the biggest bottlenecks and obstacles for the normal use of electronic current transformers in the power grid. Summary of the Invention

[0003] In view of this, the utility model proposes a high-voltage side structure of a current transformer based on quantum precision magnetic measurement, aiming to solve the problems of low accuracy and stability of existing electronic current transformers caused by anti-interference problems, temperature problems, integration drift, etc.

[0004] The present utility model proposes a high-voltage side structure of a current transformer based on quantum precise magnetic measurement. The high-voltage side structure of the current transformer includes: a housing; a primary winding disposed inside the housing, and both ends of the primary winding extend outside the housing. A iron core is sleeved outside the primary winding. The primary winding is used to connect an external wire so that the primary winding and the external wire form a primary current loop and generate a primary magnetic flux on the iron core; a secondary winding wound around the iron core, which is used to connect a secondary power supply and form a secondary current loop to generate a secondary magnetic flux with a direction opposite to that of the primary magnetic flux on the iron core; a nitrogen-vacancy color center magnetic sensor head. An opening groove is provided on the iron core, and the nitrogen-vacancy color center magnetic sensor head is disposed at the opening groove for detecting, based on quantum precise magnetic measurement, the magnetic field magnitude of the combined magnetic flux of the primary magnetic flux and the secondary magnetic flux at the opening groove as a magnetic field measurement signal, and adjusting the secondary circuit current based on the magnetic field measurement signal until the magnetic field magnitude of the combined magnetic flux at the opening groove is zero, and then determining the primary circuit current based on the secondary circuit current.

[0005] Further, in the high-voltage side structure of the current transformer based on quantum precise magnetic measurement, the primary winding is a conductor rod that penetrates through the housing, and both ends of the conductor rod extend outside the housing.

[0006] Further, in the high-voltage side structure of the current transformer based on quantum precise magnetic measurement, left and right conductor clamps are respectively provided at both ends of the conductor rod for connecting external wires.

[0007] Further, in the high-voltage side structure of the current transformer based on quantum precise magnetic measurement, a base is provided below the housing, and an insulating support is provided between the housing and the base for insulating the housing and the base; an outlet box is provided on the base for leading out the leads inside the housing and connecting to the low-voltage side structure to realize the connection between the secondary winding and the nitrogen-vacancy color center magnetic sensor head inside the housing and the low-voltage side structure.

[0008] Further, in the high-voltage side structure of the current transformer based on quantum precise magnetic measurement, the nitrogen-vacancy color center magnetic sensor head is connected with a lead-out wire, and the lead-out wire and the secondary winding are led out from inside the housing for connecting to the low-voltage side structure.

[0009] Further, in the high-voltage side structure of the current transformer based on quantum precise magnetic measurement, the lead-out wire includes: a coaxial cable and a multimode optical fiber; wherein, the coaxial cable is used to connect the microwave module of the low-voltage side structure to transmit microwaves to the nitrogen-vacancy color center magnetic sensor head; the multimode optical fiber is used to connect the optical module and the readout module of the low-voltage side structure to transmit 532nm laser to the nitrogen-vacancy color center magnetic sensor head and transmit the fluorescence radiation to the readout module to obtain the magnetic field measurement signal.

[0010] Furthermore, in the high-voltage side structure of the current transformer based on quantum precise magnetic measurement, a lead sleeve is provided outside the lead wire and the part of the secondary winding led out of the housing. The lead sleeve is formed by casting with epoxy resin, and the lead sleeve, the lead wire, and the secondary winding are cast into an integral structure.

[0011] Furthermore, in the high-voltage side structure of the current transformer based on quantum precise magnetic measurement, a magnetic field shielding layer is wrapped around the outside of the secondary winding to shield the interference of the external magnetic field.

[0012] Furthermore, in the high-voltage side structure of the current transformer based on quantum precise magnetic measurement, an insulating layer is provided between the iron core and the secondary winding and between the secondary winding and the magnetic field shielding layer; the insulating layer is an oil-paper structure.

[0013] Furthermore, in the high-voltage side structure of the current transformer based on quantum precise magnetic measurement, an electric field shielding layer is wrapped around the outside of the magnetic field shielding layer for equipotential shielding; the electric field shielding layer is a copper foil structure.

[0014] The high-voltage side structure of the current transformer based on quantum precise magnetic measurement provided by the present utility model forms a primary current loop by connecting an external wire through a primary winding inside the housing, generating a primary magnetic flux on the iron core; forms a secondary current loop by connecting a secondary power supply through a secondary winding on the iron core to generate a secondary magnetic flux opposite to the direction of the primary magnetic flux on the iron core; detects the magnetic field magnitude of the combined magnetic flux of the primary magnetic flux and the secondary magnetic flux at the opening groove through a nitrogen-vacancy color center magnetic sensor head based on quantum precise magnetic measurement, and controls and adjusts the secondary loop current on the secondary current loop based on the detected magnetic field magnitude, so that the secondary magnetic flux generated by the secondary loop current is equal to the primary magnetic flux, making the magnetic field of the combined magnetic flux of the primary magnetic flux and the secondary magnetic flux zero at the opening groove, and then based on the secondary loop current in this state, obtains the magnitude of the primary loop current according to the calculated transformation ratio; in the present utility model, the diamond nitrogen-vacancy color center magnetic measurement technology is applied to the current transformer, adopting a zero-flux structure in which the secondary winding and the primary winding generate opposite magnetomotive forces in the iron core, and judging whether the ampere-turns of the primary and secondary currents are strictly equal and controlling the magnitude of the secondary loop current by measuring the magnetic field in the iron core through the nitrogen-vacancy color center to obtain the magnitude of the primary loop current with high precision; that is to say, in the traditional zero-flux current transformer structure, a diamond nitrogen-vacancy color center quantum magnetic sensing device is added, greatly improving the detection sensitivity and accuracy of the balanced zero flux, further improving the accuracy of the strict equality of the primary and secondary side currents, thereby improving the measurement accuracy and accuracy of the current transformer, and solving the problems of low accuracy and stability of the existing electronic current transformer due to anti-interference problems, temperature problems, integral drift, etc. At the same time, in principle, the diamond nitrogen-vacancy color center can decouple the magnetic field measurement signal and the temperature measurement signal, thus avoiding the influence of temperature on the magnetic field measurement, that is, also avoiding the influence of temperature on the current measurement, and further improving the temperature stability of the current transformer. Brief Description of the Drawings

[0015] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present utility model. And throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0016] Figure 1 It is a three-dimensional structure schematic diagram of the high-voltage side structure of the current transformer based on quantum precise magnetic measurement provided by an embodiment of the present utility model;

[0017] Figure 2 It is a sectional view of the high-voltage side structure of the current transformer based on quantum precise magnetic measurement provided by an embodiment of the present utility model;

[0018] Figure 3Schematic diagram of the internal structure of the housing in the high-voltage side structure of the current transformer based on quantum precision magnetic measurement provided by the embodiments of the present invention;

[0019] Figure 4 Secondary sectional view of the high-voltage side structure of the current transformer based on quantum precision magnetic measurement provided by the embodiments of the present invention at the primary winding and the secondary winding;

[0020] Figure 5 Secondary sectional view of the internal structure of the housing in the high-voltage side structure of the current transformer based on quantum precision magnetic measurement provided by the embodiments of the present invention;

[0021] Figure 6 For Figure 5 Partial enlarged view at location A in

[0022] Figure 7 For Figure 5 Partial enlarged view at location B in

[0023] Figure 8 Parameter diagram of the fluorescence intensity and microwave frequency characteristic curve of the nitrogen-vacancy color center under the action of an external magnetic field;

[0024] Figure 9 Block diagram of the external system of the high-voltage side structure of the current transformer based on quantum precision magnetic measurement, i.e., the corresponding low-voltage side structure;

[0025] Explanation of reference numerals:

[0026] 100 - High-voltage side structure of the current transformer, 1 - Base, 101 - Outlet box, 2 - Outer shell, 21 - Main housing, 22 - Upper housing, 23 - Left cover plate, 24 - Right cover plate, 3 - Primary winding, 31 - Left conductor clamp, 32 - Right conductor clamp, 4 - Iron core, 5 - Secondary winding, 6 - Nitrogen-vacancy color center magnetic sensor head, 61 - Lead wire, 611 - Coaxial cable, 612 - Multimode optical fiber, 7 - Insulating support, 8 - Magnetic field shielding layer, 9 - Insulating layer, 10 - Casting body, 11 - Electric field shielding layer, 12 - Lead sleeve, 200 - Low-voltage side structure, 210 - Secondary power supply module, 220 - Microwave module, 230 - Optical module, 240 - Readout module. Detailed implementation manners

[0027] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be completely conveyed to those skilled in the art. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0028] In recent years, quantum precision measurement technology has utilized quantum control technology to break through many limitations of traditional measurement technology, improving the sensitivity by 2 to 3 orders of magnitude. It can effectively solve the problems of low accuracy and poor stability of existing current transformers and is the development direction of future current sensing technology.

[0029] The quantum sensing system based on diamond nitrogen-vacancy color centers has the advantages of small volume and long coherence time. Excitation and detection do not require harsh material conditions and can be carried out at room temperature, having great advantages in terms of practicality. Magnetic measurement based on diamond nitrogen-vacancy color centers has achieved a detection sensitivity of 0.9 pT·Hz -1 / 2 , which is much higher than traditional magnetic measurement methods. Moreover, in terms of the detection principle, the electron spin of the nitrogen-vacancy color center can be decoupled and coherent with the magnetic field and temperature, solving the problem of measurement temperature drift in principle. Combining the diamond nitrogen-vacancy color center magnetic measurement technology with traditional high-voltage transformer electrical engineering technology to develop a new type of quantum current transformer, thereby improving the stability and accuracy of the current transformer and providing more stable and accurate basic data for the power system.

[0030] In this embodiment, the current transformer includes a high-voltage side structure and a low-voltage side structure.

[0031] See Figures 1 to 7 , which is the preferred structure of the high-voltage side structure of the current transformer based on quantum precision magnetic measurement provided by the embodiment of the present invention. As shown in the figure, the high-voltage side structure 100 of the current transformer includes: a base 1, a housing 2, a primary winding 3, an iron core 4, a secondary winding 5, a nitrogen-vacancy color center magnetic sensor head 6, and an insulating support 7; where

[0032] The base 1 serves a supporting role; the outer shell 2 is arranged above the base 1, and the outer shell 2 and the base 1 are connected by an insulating pillar 7 to meet the requirements of voltage insulation. Specifically, the base 1 can be made of aluminum alloy, can be supported on the ground or the working surface, and serves as the support for the high-voltage side structure of the current transformer. In this embodiment, an outlet box 101 can be provided on the base 1, which is used to lead out the leads in the outer shell 2 and connect to the low-voltage side structure, so as to realize the connection between the secondary winding 5 and the nitrogen-vacancy color center magnetic sensor head 6 in the outer shell 2 and the low-voltage side structure, and then facilitate the adjustment of the secondary winding 5 based on the magnetic field measurement signal detected by the nitrogen-vacancy color center magnetic sensor head 6, so as to determine the primary circuit current. Among them, the outlet box 101 can be made of aluminum alloy, and the outlet box 101 and the base 1 can be integrally connected by welding. The outer shell 2 is arranged above the base 1, and an insulating pillar 7 is arranged between the outer shell 2 and the base 1. The insulating pillar 7 can be made of ceramic, and the upper and lower ends are respectively fixedly connected to the outer shell 2 and the base 1 by bolts, which is used to realize the insulation between the outer shell 2 and the base 1.

[0033] The primary winding 3 is arranged inside the outer shell 2, and both ends of the primary winding 3 extend to the outside of the outer shell 2. An iron core 4 is sleeved outside the primary winding 3. The primary winding 3 is used to connect to an external wire, so that the primary winding 3 and the external wire form a primary current loop and generate a primary magnetic flux on the iron core 4. Specifically, the primary winding 3 can be a conductor rod, which passes through the outer shell 2, and both ends of the conductor rod extend to the outside of the outer shell 2 to connect to the external wire, so that the primary winding 3 and the external wire are connected in series to form a primary current loop, and the primary winding 3 can also generate a primary magnetic flux on the iron core 4 sleeved outside the primary winding 3. Of course, the primary winding 3 can also be of other structures, such as a wire wound around a support rod as the primary winding 3. The structure of the primary winding 3 is not limited in this embodiment. Among them, the primary winding 3 is a conductor rod, with a simple structure and a turn number of 1 turn, which is convenient for installation and subsequent calculation of the secondary circuit current; the conductor rod can be made of C1100 brand pure copper and is connected to the outer shell 2 by bolts to realize the fixation of the conductor rod. Both ends of the conductor rod (such as Figure 1 the left and right ends shown) are respectively provided with a left conductor clamp 31 and a right conductor clamp 32, which are used to connect to the external wire; among them, the left conductor clamp 31 and the right conductor clamp 32 are fixedly pressed on the conductor rod by bolts, which are used to connect to the external wire to form a primary side current loop and generate a primary magnetic flux on the iron core 4. In this embodiment, the outer shell 2, the primary winding 3, that is, the conductor rod, the left conductor clamp 31 and the right conductor clamp 32 can be at the same potential of the primary high voltage. As Figure 4As shown, the iron core 4 is of an annular structure and is sleeved on the conductor rod, facilitating the disassembly and assembly between the two. In this embodiment, an opening groove is provided on the iron core 4, that is, a groove gap is formed as a slit, where the nitrogen-vacancy color center magnetic sensor head 6 can be placed, and the lead wire 61 on the nitrogen-vacancy color center magnetic sensor head 6 can be led out; in particular, the opening groove can be arranged downward to facilitate the downward leading out of the lead wire 61 of the nitrogen-vacancy color center magnetic sensor head 6.

[0034] The secondary winding 5 is wound around the iron core 4, used to connect to the secondary power supply and form a secondary current loop to generate a secondary magnetic flux on the iron core 4 in a direction opposite to the primary magnetic flux direction. Specifically, outside the iron core 4, that is, the copper wire secondary winding 5 is wound around the entire outer surface of the iron core 4 and evenly wound along its length direction for the conduction of the secondary circuit current to generate a secondary magnetic flux on the iron core 4 in a direction opposite to the primary magnetic flux direction.

[0035] The nitrogen-vacancy color center magnetic sensor head 6 is arranged at the opening groove, used to detect the magnetic field magnitude of the combined magnetic flux of the primary magnetic flux and the secondary magnetic flux at the opening groove based on quantum precise magnetic measurement as a magnetic field measurement signal, so as to adjust the secondary circuit current based on the magnetic field measurement signal until the magnetic field magnitude of the combined magnetic flux at the opening groove is zero, and then determine the primary circuit current based on the secondary circuit current. Specifically, the nitrogen-vacancy color center magnetic sensor head 6 is connected with a lead wire 61. The nitrogen-vacancy color center magnetic sensor head 6 is used to detect the magnetic field magnitude of the combined magnetic flux of the primary magnetic flux and the secondary magnetic flux, that is, the subtracted magnetic flux, at the slit as a magnetic field measurement signal, and transmit the magnetic field measurement signal to the outside of the high-voltage side structure of the mutual inductor through the lead wire 61, for example, it can be transmitted to the low-voltage side structure of the mutual inductor, so as to adjust the secondary circuit current of the secondary winding 5 based on the magnetic field measurement signal to make the magnetic field detected by the nitrogen-vacancy color center magnetic sensor head 6 zero, and then the primary circuit current can be calculated according to the secondary circuit current. In this embodiment, the lead wire 61 and the secondary winding 5 can be led out from the housing 2, pass through the insulating post 7 and the base 1, and be led out from the base 1, used to connect the low-voltage side structure to transmit microwave and laser to the nitrogen-vacancy color center magnetic sensor head 6 through the lead wire 61, and the magnetic field measurement signal obtained by the nitrogen-vacancy color center magnetic sensor head 6 can also be transmitted to the low-voltage side structure through the lead wire 61, so as to adjust the secondary circuit current on the secondary winding 5 based on the magnetic field measurement signal.

[0036] In this embodiment, to prevent components such as the secondary winding 5 from being interfered by external magnetic fields, resulting in inaccurate magnetic field measurement signals obtained by the nitrogen-vacancy color center magnetic sensor head 6, preferably, a magnetic field shielding layer 8 is wrapped around the outside of the secondary winding 5 to shield the interference of external magnetic fields. Specifically, the magnetic field shielding layer 8 can be wrapped around the secondary winding 5, and the magnetic field shielding layer 8 can be a permalloy magnetic field shielding layer 8, which is used to shield external magnetic field interference, thereby further improving the measurement accuracy of the current transformer. Insulation layers 9 are provided between the iron core 4 and the secondary winding 5, and between the secondary winding 5 and the magnetic field shielding layer 8. The insulation layer 9 has an oil-paper structure, that is, oil-paper insulation is adopted. In this embodiment, the iron core 4, the secondary winding 5, the magnetic field shielding layer 8, and the insulation layer 9 can be cast into an integral structure through a casting body 10. Among them, the casting body 10 can be epoxy resin, that is, the iron core 4, the secondary winding 5, the magnetic field shielding layer 8, and the insulation layer 9 can be integrally formed by epoxy resin casting. To further improve the detection accuracy of the nitrogen-vacancy color center magnetic sensor head 6, preferably, an electric field shielding layer 11 is wrapped around the outside of the magnetic field shielding layer 8 for equipotential shielding. The electric field shielding layer 11 can be a copper foil structure, that is, a copper foil electric field shielding layer 11.

[0037] In this embodiment, a lead sleeve 12 is provided outside the lead wire 61 of the nitrogen-vacancy color center magnetic sensor head 6 and the part of the secondary winding 5 led out of the housing 2. The lead sleeve 12 is formed by epoxy resin casting, and the lead sleeve 12, the lead wire 61, and the secondary winding 5 are cast into an integral structure. Specifically, the lead sleeve 12 has a hollow structure, and the inside is used for wiring and insulation of the secondary winding 5 and the lead wire 61 of the nitrogen-vacancy color center magnetic sensor head 6. The lead sleeve 12 is formed by pouring epoxy resin through a mold and is cast into an integral body with the magnetic field shielding layer 8, the secondary winding 5, and the iron core 4. A copper foil electric field shielding layer 11 is wrapped around the epoxy casting of the magnetic field shielding layer 8 for equipotential shielding. The overall structure including the electric field shielding layer 11, the magnetic field shielding layer 8, the secondary winding 5, and the iron core 4 is fixed on the base 1 through the lead sleeve 12. Among them, the electric field shielding layer 11, the lead sleeve 12, the base 1, and the outlet box 101 are at ground potential. In this embodiment, the inside of the current transformer is filled with SF6 gas for insulation between the primary high voltage and the ground potential.

[0038] In this embodiment, the lead wire 61 of the nitrogen-vacancy color center magnetic sensor head 6 includes a coaxial cable 611 and a multimode optical fiber 612. Among them, the coaxial cable 611 is used to connect the microwave module 220 on the low-voltage side structure to transmit microwaves to the nitrogen-vacancy color center magnetic sensor head 6. The multimode optical fiber 612 is used to connect the optical module 230 and the readout module 240 on the low-voltage side structure to transmit 532 nm laser to the nitrogen-vacancy color center magnetic sensor head 6 and transmit the fluorescence radiation to the readout module 240 to obtain the magnetic field measurement signal.

[0039] Specifically, the nitrogen-vacancy color center magnetic sensor head 6 leads out a multimode optical fiber 612 and a coaxial cable 611, and is led out through the inside of the lead sleeve 12 to be respectively connected to the external low-voltage side structure. Furthermore, it is connected to the microwave module 220 of the low-voltage side structure through the coaxial cable 611 to transmit microwaves to the nitrogen-vacancy color center magnetic sensor head 6, and is connected to the optical module 230 and the readout module 240 of the low-voltage side structure through the multimode optical fiber 612 to transmit 532 nm laser to the nitrogen-vacancy color center magnetic sensor head 6. The nitrogen-vacancy color center magnetic sensor head 6 can radiate fluorescence under the action of 532 nm laser and microwaves, and the fluorescence radiated through the multimode optical fiber 612 is transmitted to the readout module 240, so as to obtain the magnetic field magnitude through the readout module 240 based on the fluorescence intensity of the radiation.

[0040] In this embodiment, the nitrogen-vacancy color center magnetic sensor head 6 can be a diamond nitrogen-vacancy color center. The diamond nitrogen-vacancy color center is a special point defect structure in diamond, and its structure is that a nitrogen atom replaces a carbon atom and there is a hole at a neighboring position. The nitrogen-vacancy color center has a special energy level structure. Under the action of 532 nm laser and microwaves with a specific frequency, it will radiate fluorescence with a wavelength of 637 nm to 800 nm. Without the action of an external magnetic field, the characteristic curve of its fluorescence intensity and microwave frequency is as Figure 8 shown by curve (a) in the figure. There is a resonance peak when the microwave frequency is 2.87 GHz. Under the action of an external magnetic field, the characteristic curve of the fluorescence intensity and microwave frequency is as Figure 8 shown by curve (b) in the figure. A single resonance peak splits into two resonance peaks, and the frequency difference Δf of its resonance peaks has a linear relationship of Δf = 2γB with the magnitude of the external magnetic field, where γ = 2.8 MHz / Gs. Therefore, the magnitude of the magnetic field can be detected according to the fluorescence intensity.

[0041] Continue to refer to Figures 1 to 2 , the housing 2 can include: a main housing 21 and an upper housing 22; wherein, the upper housing 22 covers the upper opening end of the upper housing 22 so that a sealed cavity is formed between the main housing 21 and the upper housing 22, so that structures such as the primary winding 3 and the secondary winding 5 can be placed in this sealed cavity, and a primary magnetic flux and a secondary magnetic flux can be generated in this sealed cavity to detect the magnetic field magnitude of the combined magnetic flux of the primary magnetic flux and the secondary magnetic flux at the opening groove. Among them, SF6 gas can be filled in this sealed cavity. In this embodiment, the main housing 21 can be provided with a detachable left cover plate 23 and a right cover plate 24 to facilitate the installation and fixation of the primary magnetic flux. Among them, the upper housing 22, the main housing 21, the left cover plate 23, and the right cover plate 24 are aluminum alloy die-castings and are fixed by bolts. The primary magnetic flux, that is, the primary conductor rod, can be fixed to the left cover plate 23 and the right cover plate 24 by bolts.

[0042] In this embodiment, the upper housing 22, the main housing 21, the primary conductor, the left cover plate 23, the right cover plate 24, the left conductor clamp 31, and the right conductor clamp 32 are at the same potential of the primary high voltage.

[0043] See Figure 9 , which is a structural block diagram of an external system corresponding to the high-voltage side structure of a current transformer based on quantum precision magnetic measurement, i.e., the structure of the corresponding low-voltage side. As shown in the figure, the low-voltage side structure 200 may include: a secondary power supply module 210 for connecting to the secondary winding 5, a microwave module 220 for transmitting microwaves to the nitrogen-vacancy color center magnetic sensor head 6, an optical module 230 for transmitting 532-nm laser light to the nitrogen-vacancy color center magnetic sensor head 6, and a readout module 240 for reading the radiation fluorescence emitted by the nitrogen-vacancy color center magnetic sensor head 6. The readout module 240 is used to obtain the magnitude of the magnetic field, i.e., the magnetic field measurement signal, based on the radiation fluorescence intensity of the radiation fluorescence, to determine whether the primary magnetic flux and the secondary magnetic flux are strictly equal according to the magnetic field measurement signal, and output a signal to control and adjust the secondary circuit current generated by the secondary power supply until the primary magnetic flux and the secondary magnetic flux are equal, i.e., the magnetic field measurement signal is zero. Furthermore, when the magnetic field measurement signal is zero, the magnitude of the primary circuit current is obtained by calculating the turns ratio based on the secondary circuit current.

[0044] Specifically, the secondary power supply module 210 is connected in series with the secondary winding 5 so that the secondary power supply module 210 and the secondary winding 5 form a secondary current loop, generate a secondary circuit current, and generate a secondary magnetic flux in the iron core 4 to cancel the primary magnetic flux generated by the primary circuit current in the iron core 4, for regulating and controlling the secondary circuit current. The microwave module 220 is connected to the nitrogen-vacancy color center magnetic sensor head 6 and can transmit microwaves to the nitrogen-vacancy color center magnetic sensor head 6 through a coaxial cable 611. The optical module 230 is connected to the nitrogen-vacancy color center magnetic sensor head 6 and can transmit 532-nm laser light to the nitrogen-vacancy color center magnetic sensor head 6 through a multimode optical fiber 612. The readout module 240 is connected to the nitrogen-vacancy color center magnetic sensor head 6 and can transmit the radiation fluorescence to the readout module 240 through the multimode optical fiber 612, obtain the radiation fluorescence emitted by the nitrogen-vacancy color center magnetic sensor head, and determine the magnitude of the magnetic field at the opening groove of the combined magnetic flux of the primary magnetic flux and the secondary magnetic flux based on the intensity of the radiation fluorescence, i.e., obtain the magnetic field measurement signal. Determine whether the primary magnetic flux and the secondary magnetic flux are strictly equal according to the magnetic field measurement signal, and output a signal to control the secondary circuit current generated by the secondary power supply so that the primary magnetic flux and the secondary magnetic flux are completely canceled, i.e., the primary magnetic flux and the secondary magnetic flux are equal, that is, the magnetic field measurement signal is zero. Furthermore, based on the secondary circuit current when the magnetic field measurement signal is zero, the magnitude of the primary circuit current is obtained by calculating the turns ratio. Among them, the calculated turns ratio is the turns ratio of the primary winding and the secondary winding. In this embodiment, the number of turns of the primary winding is 1 turn, then the calculated turns ratio is equal to the number of turns of the secondary winding, and the primary circuit current is equal to the product of the secondary circuit current and the calculated turns ratio.

[0045] In summary, for the high-voltage side structure of the current transformer based on quantum precision magnetic measurement provided in this embodiment, the primary current loop is formed by connecting the external wire through the primary winding 3 inside the housing 2 to generate a primary magnetic flux on the iron core 4; the secondary current loop is formed by connecting the secondary power supply through the secondary winding 5 on the iron core 4 to generate a secondary magnetic flux on the iron core 4 in the opposite direction to the primary magnetic flux; the nitrogen-vacancy color center magnetic sensor head 6 is used to detect the magnetic field magnitude at the opening groove of the combined magnetic flux of the primary magnetic flux and the secondary magnetic flux based on quantum precision magnetic measurement, and based on the detected magnetic field magnitude, the secondary loop current on the secondary current loop is controlled and adjusted so that the secondary magnetic flux generated by the secondary loop current is equal to the primary magnetic flux, making the magnetic field of the combined magnetic flux of the primary magnetic flux and the secondary magnetic flux zero at the opening groove, and then based on the secondary loop current in this state, the magnitude of the primary loop current is obtained according to the calculated transformation ratio; in this embodiment, the diamond nitrogen-vacancy color center magnetic measurement technology is applied to the current transformer, and a zero-flux structure with opposite magnetomotive forces generated by the secondary winding 5 and the primary winding 3 in the iron core 4 is adopted. The magnetic field in the iron core 4 is measured by the nitrogen-vacancy color center to determine whether the ampere-turns of the primary and secondary currents are strictly equal and to control the magnitude of the secondary loop current, so as to obtain the magnitude of the primary loop current with high precision; that is to say, in the traditional zero-flux current transformer structure, a diamond nitrogen-vacancy color center quantum magnetic sensing device is added to greatly improve the balance zero-flux detection sensitivity and accuracy, and further improve the accuracy of the strict equality of the primary and secondary side currents, thereby improving the measurement accuracy and accuracy of the current transformer, and solving the problems of low accuracy and stability of the existing electronic current transformer due to anti-interference problems, temperature problems, integral drift, etc. At the same time, in principle, the diamond nitrogen-vacancy color center can decouple the magnetic field measurement signal and the temperature measurement signal, thus avoiding the influence of temperature on the magnetic field measurement, that is, also avoiding the influence of temperature on the current measurement, and further improving the temperature stability of the current transformer.

[0046] It should be noted that in the description of the present invention, the terms indicating the direction or position relationship such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the direction or position relationship shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0047] In addition, it should be noted that in the description of the present utility model, unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a direct connection, or an indirect connection through an intermediate medium, and it may be the communication inside two components. For those skilled in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0048] Obviously, those skilled in the art can make various modifications and variations to the present utility model without departing from the spirit and scope of the present utility model. Thus, if these modifications and variations of the present utility model fall within the scope of the claims of the present utility model and their equivalent technologies, the present utility model also intends to include these modifications and variations.

Claims

1. A current transformer high voltage side structure based on quantum precision magnetic measurement, characterized in that: include: shell; A primary winding is arranged inside the shell, and both ends of the primary winding extend to the outside of the shell, an iron core is sleeved outside the primary winding, and the primary winding is used to connect an external wire so that the primary winding and the external wire form a primary current loop and generate a primary magnetic flux on the iron core; A secondary winding, wrapped around the iron core, is used to connect a secondary power supply and form a secondary current loop to generate a secondary magnetic flux on the iron core in a direction opposite to the primary magnetic flux; A nitrogen vacancy color center magnetic sensor head, wherein an open groove is provided on the iron core, and the nitrogen vacancy color center magnetic sensor head is arranged at the open groove, and is used to detect the magnetic field size of the combined magnetic flux of the primary magnetic flux and the secondary magnetic flux at the open groove based on quantum precision magnetic measurement, as a magnetic field measurement signal, so as to adjust the secondary loop current based on the magnetic field measurement signal until the magnetic field size of the combined magnetic flux at the open groove is zero, and then determine the primary loop current based on the secondary loop current.

2. The current transformer high voltage side structure based on quantum precision magnetic measurement according to claim 1 is characterized in that: The primary winding is a conductor rod which passes through the housing, and both ends of the conductor rod extend to the outside of the housing.

3. The current transformer high voltage side structure based on quantum precision magnetic measurement according to claim 2 is characterized in that: The two ends of the conductor rod are respectively provided with a left conductor clamp and a right conductor clamp for connecting external wires.

4. The high-voltage side structure of a current transformer based on quantum precision magnetic measurement according to any one of claims 1 to 3, characterized in that: A base is provided below the shell, and an insulating support is provided between the shell and the base to achieve insulation between the shell and the base; The base is provided with an outlet box for leading out the leads in the shell and connecting the low-voltage side structure, so as to realize the connection between the secondary winding in the shell, the nitrogen vacancy color center magnetic sensor head and the low-voltage side structure.

5. The current transformer high voltage side structure based on quantum precision magnetic measurement according to any one of claims 1 to 3, characterized in that: The nitrogen vacancy color center magnetic sensor head is connected with a lead wire, and the lead wire and the secondary winding are led out from the shell for connecting to the low-voltage side structure.

6. The current transformer high voltage side structure based on quantum precision magnetic measurement according to claim 5 is characterized in that: The lead-out wires include: coaxial cables and multimode optical fibers; wherein, The coaxial cable is used to connect the microwave module of the low-voltage side structure to transmit microwaves to the nitrogen vacancy color center magnetic sensor head; The multimode optical fiber is used to connect the optical module and the readout module of the low-voltage side structure to transmit 532nm laser to the nitrogen vacancy color center magnetic sensor head, and transmit the radiated fluorescence to the readout module to obtain the magnetic field measurement signal.

7. The current transformer high voltage side structure based on quantum precision magnetic measurement according to claim 5, characterized in that: The lead wire and the secondary winding are led out to the outer part of the shell and a lead wire sleeve is provided on the outside. The lead wire sleeve is molded by epoxy resin casting, and the lead wire sleeve, the lead wire and the secondary winding are cast into an integrated structure.

8. The current transformer high voltage side structure based on quantum precision magnetic measurement according to any one of claims 1 to 3, characterized in that: The secondary winding is wrapped with a magnetic field shielding layer outside to shield interference from external magnetic fields.

9. The current transformer high voltage side structure based on quantum precision magnetic measurement according to any one of claims 1 to 3, characterized in that: An insulating layer is provided between the iron core and the secondary winding, and between the secondary winding and the magnetic field shielding layer; The insulating layer is of oil-paper structure.

10. The high-voltage side structure of a current transformer based on quantum precision magnetic measurement according to any one of claims 1 to 3, characterized in that: The outside of the magnetic field shielding layer is surrounded by an electric field shielding layer for equipotential shielding; The electric field shielding layer is a copper foil structure.

Images