New leakage current sensor for photovoltaic systems

Abstract

The present application discloses a novel leakage current sensor for photovoltaic systems, which includes a housing, a winding assembly, a magnetic probe assembly, a magnetic core assembly and an electromagnetic shielding member. The winding assembly is arranged in the housing. The winding assembly includes a coil base and a spiral coil. The coil base has a through hole and a spiral slot hole located in the through hole in the axial direction. The spiral coil is arranged in the spiral slot hole. The magnetic probe assembly is arranged in the through hole. The magnetic probe assembly has an amorphous material body with low saturation magnetic flux and a MEMS coil. The MEMS coil is etched in the amorphous material body. The magnetic core assembly is arranged in the housing. The magnetic core assembly has a first side and a second side opposite to each other. The first side has a mounting groove. Part of the first side and the mounting groove are located in the through hole, and the magnetic probe assembly is located in the mounting groove. The present application can greatly improve the winding efficiency of the winding assembly and the magnetic probe assembly, reduce the structure of the leakage current sensor, facilitate assembly, and meet the requirements of energy-saving and emission-reduction production.

Description

Technical Field

[0001] The present application relates to a photovoltaic inverter, and in particular to a novel leakage current sensor applied to a photovoltaic system. Background Art

[0002] Photovoltaic inverter is a very important device in photovoltaic system. Its main function is to convert the direct current generated by photovoltaic modules into alternating current. In addition, photovoltaic inverter also undertakes important functions such as detecting the operating status of modules, power grids, cables, communicating with the outside world, and system safety management. According to Article 7.10.2 of NB / T32004-2013 "Technical Specifications for Photovoltaic Power Generation Grid-connected Inverters", photovoltaic inverters should provide leakage current detection in any case where the AC circuit breaker is closed when the photovoltaic inverter is connected to the AC power grid. Leakage current detection should be able to detect the total (including DC and AC parts) effective value current and continuous residual current. If the continuous residual current exceeds the following limit, the photovoltaic inverter should be disconnected within 0.3s and send a fault signal, where: 1) For inverters with a rated output less than or equal to 30KVA, 300mA; 2) For inverters with a rated output greater than 30KVA, 10mA / KVA.

[0003] Due to the two characteristics of the current leakage current in photovoltaic systems: 1. The components are complex, with both DC and AC parts; 2. The current value is very small, usually at the milliampere level, which requires extremely high accuracy and requires a dedicated current sensor. The photovoltaic standard of the Ministry of Energy stipulates that Type B must be used for the detection of photovoltaic leakage current, that is, a leakage current sensor that can measure both AC and DC leakage current. Please refer to Figure 1 , which is an exploded view of a current leakage current sensor; as shown in the figure, the current leakage current sensor generally consists of an upper shell 10, a lower shell 20, and a magnetic probe assembly 30, a winding assembly 40, a magnetic core assembly 50, and a shielding assembly 60 located between the upper shell 10 and the lower shell 20. In the process of implementing this application, the applicant found that the current structure of the leakage current sensor has at least the following technical problems:

[0004] 1. The magnetic probe assembly 30 has a complex structure, is inconvenient to assemble, and has poor accuracy and consistency;

[0005] 2. The winding of the winding assembly 40 is time-consuming and labor-intensive, which is not conducive to energy-saving production, and the winding flatness of the coil is poor, and the inductance is unstable;

[0006] 3. The magnetic core assembly 50 is a single-piece assembly, and the single-piece magnetic core needs to be assembled 12 times. The assembly process is complicated and is not conducive to mass production;

[0007] 4. The shielding assembly 60 is inconvenient to assemble, which wastes labor and materials, and requires a customized mold to prepare the shielding assembly.

[0008] In summary, the current leakage current sensor has problems such as complex structure, inconvenient assembly, poor accuracy and consistency, which do not meet the current energy-saving production requirements. Therefore, a new leakage current sensor is urgently needed to simplify the structure of the leakage current sensor, reduce its production and assembly requirements, and make it meet the requirements of energy-saving and emission-reduction production. Summary of the invention

[0009] In order to solve the above technical problems, the embodiment of the present application provides a new leakage current sensor applied to a photovoltaic system. The specific technical solution is as follows:

[0010] A new leakage current sensor for photovoltaic system is provided, which includes a shell, a winding assembly, a magnetic probe assembly, a magnetic core assembly and an electromagnetic shielding component. The winding assembly is arranged in the shell. The winding assembly includes a coil base and a spiral coil. The coil base has a through hole and a spiral groove hole located in the through hole in the axial direction. The spiral coil is arranged in the spiral groove hole. The magnetic probe assembly is arranged in the through hole. The magnetic probe assembly has an amorphous material body with low saturation magnetic flux and a MEMS coil. The MEMS coil is etched in the amorphous material body. The magnetic core assembly is arranged in the shell. The magnetic core assembly has a first side and a second side opposite to each other. The first side has a mounting groove. Part of the first side and the mounting groove are located in the through hole, and the magnetic probe assembly is located in the mounting groove. The second side is located outside the through hole. The electromagnetic shielding component is arranged on the inner wall of the shell.

[0011] In one embodiment, the housing includes an upper housing and a lower housing, the upper housing covers the lower housing, and the winding assembly, the magnetic probe assembly and the magnetic core assembly are located between the upper housing and the lower housing.

[0012] In one embodiment, the coil base includes an upper base and a lower base, a first through groove is opened on the side adjacent to the upper base and a second through groove is opened on the side adjacent to the lower base. The first through groove and the second through groove are connected to form a through hole, and the spiral groove hole is located between the first through groove and the second through groove.

[0013] In one embodiment, the material of the upper substrate is a silicon wafer, and a first through groove and a spiral groove hole are opened on one side of the upper substrate through a photolithography process. The material of the lower substrate is a silicon wafer, and a second through groove and a spiral groove hole are opened on the lower substrate through a photolithography process. The material of the spiral coil is liquid alloy, and the liquid alloy is filled into the spiral groove holes of the first through groove and the second through groove through a micro-casting forming process to form a liquid alloy spiral coil.

[0014] In one embodiment, the liquid alloy spiral coil is a single-layer structure or a double-layer serial structure.

[0015] In one embodiment, the material of the amorphous material body is a cobalt-based amorphous alloy.

[0016] In one embodiment, the magnetic core component includes a plurality of first magnetic chips and a plurality of second magnetic chips, the plurality of first magnetic chips are stacked together to form a first magnetic chip group, one side of the first magnetic chip group has a first notch, and the other side has a plurality of first slots, the plurality of first slots are formed by stacking first magnetic chips of different lengths, a plurality of second magnetic chips are stacked together to form a second magnetic chip group, one side of the second magnetic chip group has a second notch, and the other side has a plurality of second slots, the plurality of second slots are formed by stacking second magnetic chips of different lengths, the first magnetic chip group is docked with the second magnetic chip group, the first notch is docked with the second notch to form an installation groove, and the first slot and the second slot are inserted into each other.

[0017] In one embodiment, the electromagnetic shielding element uses an iron-based nanocrystalline magnetic shielding sheet.

[0018] In one embodiment, it further includes: pins and a PCB board, the pins are connected to the PCB board, and the PCB board is electrically connected to the winding assembly and the magnetic probe assembly.

[0019] In one of the embodiments, an integral conversion circuit is provided on the PCB board, and the integral conversion circuit is used to convert the PWM signal output by the magnetic probe assembly into a voltage signal, and amplify it to convert it into an output current and output it to the winding assembly, and in the zero magnetic flux state, the formula I=Iout*N is satisfied, wherein I is the input current, N is the number of turns of the winding assembly, and Iout is the output current after the voltage signal is amplified.

[0020] In the embodiment of the present application, by setting the spiral coil in the spiral slot of the axial through hole of the coil substrate and etching the MEMS coil in the amorphous material body, the winding efficiency of the winding assembly and the magnetic probe assembly can be greatly improved, the structure of the leakage current sensor can be reduced, and the assembly is convenient, which meets the requirements of energy-saving and emission-reduction production. At the same time, the spiral coil and MEMS coil of the present application can be prepared by filling liquid alloy to further solve the problem of winding flatness. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0022] Figure 1 This is an exploded view of the current leakage current sensor;

[0023] Figure 2 is a three-dimensional diagram of a novel leakage current sensor applied to a photovoltaic system of the present application;

[0024] Figure 3 is a three-dimensional diagram of the novel leakage current sensor applied to the photovoltaic system of the present application without the upper shell;

[0025] Figure 4 is a partially exploded view of a novel leakage current sensor for use in a photovoltaic system of the present application;

[0026] Figure 5 is an exploded view of a novel leakage current sensor for use in a photovoltaic system of the present application;

[0027] Figure 6 is a perspective view of a winding assembly of the present application;

[0028] Figure 7 is a perspective view of a magnetic probe assembly of the present application;

[0029] Figure 8 is a circuit topology diagram of a novel leakage current sensor applied to a photovoltaic system of the present application;

[0030] Fig. 9 It is a three-dimensional diagram of the current winding assembly;

[0031] Fig.10 This is a partial exploded view of the current winding assembly;

[0032] Fig.11 It is a three-dimensional picture of the current magnetic probe assembly;

[0033] Fig.12 This is a partial exploded view of the current magnetic probe assembly;

[0034] Fig.13 is a three-dimensional diagram of the magnetic core assembly of the present application;

[0035] Fig.14 is a three-dimensional diagram of the first magnetic chip set of the present application;

[0036] Fig.15 It is an assembly state diagram of the magnetic core assembly, the winding assembly and the magnetic probe assembly of the present application;

[0037] Fig.16 It is a side view of the assembly of the magnetic core component, the winding component and the magnetic probe component of the present application;

[0038] Fig.17 This is a three-dimensional picture of the current magnetic core assembly;

[0039] Fig.18 This is a three-dimensional picture of the current magnetic chip;

[0040] Fig.19 This is an exploded view of the current shield assembly;

[0041] Fig. 20 It is a three-dimensional diagram of the iron-based nanocrystalline magnetic shielding sheet of the present application. DETAILED DESCRIPTION

[0042] The embodiments of the present application will be described below with reference to the accompanying drawings. In these drawings, the same reference numerals represent the same or similar components or method flows.

[0043] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0044] See also Figures 2 to 7 , Figure 2 is a three-dimensional diagram of a novel leakage current sensor applied to a photovoltaic system of the present application, Figure 3 This is a three-dimensional image without the upper shell. Figure 4 It is a partial exploded diagram. Figure 5 It is an exploded diagram. Figure 6 is a perspective view of the winding assembly and Figure 7: is a perspective view of a magnetic probe assembly; as shown in the figure, the novel leakage current sensor 100 applied to a photovoltaic system in this embodiment is mainly suitable for leakage current detection of a photovoltaic system. In this embodiment, it includes a housing 1, a winding assembly 2, a magnetic probe assembly 3, a magnetic core assembly 4 and an electromagnetic shielding member 5. The winding assembly 2 is arranged in the housing 1. The winding assembly 2 includes a coil matrix 21 and a spiral coil 22, and the coil matrix 21 has a through hole 211 and a spiral slot hole (not shown in the figure) in the axial direction of the through hole 211. The spiral coil 22 is arranged in the spiral slot hole. The spiral coil 22 can be prepared by filling the spiral slot hole with liquid alloy. The magnetic probe assembly 3 is arranged in the through hole 211. The magnetic probe assembly 3 has an amorphous material body 31 with a low saturation magnetic flux and a MEMS coil 32. The MEMS coil 32 is etched in the amorphous material body 31. The magnetic core assembly 4 is arranged in the housing 1. The magnetic core assembly 4 has a first side 41 and a second side 42 opposite to each other. The first side 41 has a mounting groove 411. Part of the first side 41 and the mounting groove 411 are located in the through hole 211, and the magnetic probe assembly 3 is located in the mounting groove 411. The second side 42 is located outside the through hole 211. The electromagnetic shielding member 5 is arranged in a close fit to the inner wall of the shell 1. The new leakage current sensor 100 of this embodiment arranges the spiral coil 22 in the spiral groove hole of the axial through hole 211 of the coil base 21, and etches the MEMS coil 32 in the amorphous material body 31, which can greatly improve the winding efficiency of the winding assembly 2 and the magnetic probe assembly 3, reduce the structure of the leakage current sensor, and facilitate assembly, which meets the requirements of energy-saving and emission-reduction production. At the same time, the spiral coil 22 and the MEMS coil 32 of this embodiment can be prepared by filling liquid alloy to further solve the problem of winding flatness.

[0045] See also Figures 2 to 5 As shown, in this embodiment, the novel leakage current sensor 100 applied to the photovoltaic system further includes a pin 6 and a PCB board 7. Pin 6 is connected to the PCB board 7. Pin 6 is used to connect an external device, and pin 6 includes but is not limited to a 2PIN connector 61 and a 4PIN connector 62. PCB board 7 is electrically connected to the winding assembly 2 and the magnetic probe assembly 3. Please refer to Figure 8, which is the circuit topology diagram of the novel leakage current sensor applied to the photovoltaic system of the present application; as shown in the figure, an integral conversion circuit 71 is arranged on the PCB board 7. The magnetic probe component 3 is an amorphous material body 31 with low saturation magnetic flux. The magnetic probe senses and outputs a PWM signal to the PCB board 7. The integral conversion circuit 71 converts the PWM signal output by the magnetic probe component 3 into a voltage signal, and amplifies it into an output current (Iout) and outputs it to the winding component 2, generating a magnetic field Hm (t) to compensate the magnetic field H0 (t) generated by the primary measurement input current I, so that the magnetic probe works in a zero magnetic field state, that is, H0 (t) = Hm (t). In the zero magnetic flux state, the winding component 2 (compensation coil, the number of turns is N) satisfies I = Iout * N in the zero magnetic flux state, and the compensation current is converted into a voltage signal through the sampling resistor Rm, and then the required voltage signal Vout is obtained through the operational amplifier, Vout = I / N * Rm * A, where A is the amplifier gain.

[0046] The following is a further detailed description of the novel leakage current sensor 100 applied to the photovoltaic system according to the present embodiment: Figure 2 and Figure 5 As shown, the housing 1 includes an upper housing 11 and a lower housing 12. The upper housing 11 covers the lower housing 12. The lower housing 12 has a hollow cylinder 121 inside, and can be formed by injection molding, 3D printing and other molding methods. The upper housing 11 has a circular hole 111 corresponding to the hollow cylinder 121. The winding assembly 2, the magnetic probe assembly 3 and the magnetic core assembly 4 are located between the upper housing 11 and the lower housing 12. The winding assembly 2, the magnetic probe assembly 3, the magnetic core assembly 4 and the PCB board 7 are fixed in the housing 1 by the mutual cooperation between the upper housing 11 and the lower housing 12. The upper housing 11 and the lower housing 12 can also be detachably connected by means of buckles, pins, threads and the like.

[0047] See also Figure 5 and Figure 6As shown, the coil substrate 21 includes an upper substrate 212 and a lower substrate 213. A first through groove 2121 is provided on one side of the upper substrate 212 and the lower substrate 213. The material of the upper substrate 212 uses a silicon wafer, and a first through groove 2121 and a spiral groove hole are provided on one side of the upper substrate 212 by a photolithography process. A second through groove 2131 is provided on one side of the lower substrate 213 and the upper substrate 212. The material of the lower substrate 213 uses a silicon wafer, and a second through groove 2131 and a spiral groove hole are provided on the lower substrate 213 by a photolithography process. The upper substrate 212 and the lower substrate 213 can be made into a whole by a chip packaging process, and the first through groove 2121 and the second through groove 2131 are connected to form a through hole 211, and the spiral groove hole is located at the first through groove 2121 and the second through groove 2131. The material of the spiral coil 22 is liquid alloy, and the liquid alloy is filled into the spiral groove holes of the first through groove 2121 and the second through groove 2131 through a micro casting process to form a liquid alloy spiral coil. The liquid alloy spiral coil can adopt a single-layer structure with 1000 turns. The liquid alloy spiral coil can also adopt a double-layer series structure with 500 turns per layer.

[0048] As mentioned above, please refer to Fig. 9 and Fig.10 , which is a stereoscopic diagram and a partially exploded diagram of the current winding assembly; as shown in the figure, the current winding assembly 40 needs to wind the wire 402 on the winding skeleton 401, and in the later stage, it is also necessary to press the pin 403 on the winding skeleton 401, and the assembly process of the winding assembly 40 is relatively complicated. Compared with the current preparation process of the winding assembly 40, the winding assembly 2 of this embodiment does not require cumbersome processes such as winding, and the upper substrate 212 and the lower substrate 213 of this embodiment can be directly made into a whole through the chip packaging process, thereby reducing labor intensity and improving production efficiency. At the same time, since the winding 402 of the current winding assembly 40 is manually wound, the flatness of the winding 402 of the current winding assembly 40 is poor, resulting in poor consistency of parameters such as inductance. The spiral coil 22 of the winding assembly 2 of the present embodiment is prepared by filling liquid alloy into the spiral groove hole of the coil base 21. The structure of the spiral coil 22 is flatter, and the resistance of the spiral coil 22 can be adjusted according to the composition of the liquid alloy. The spiral coil 22 is more designable and the consistency of parameters such as inductance is better.

[0049] See also Fig.11 and Fig.12, which is a three-dimensional diagram and a partially exploded diagram of the current magnetic probe assembly; as shown in the figure, when the current magnetic probe assembly 30 is assembled, the magnetic probe skeleton 301 is injection molded, the pin 302 is pressed into the magnetic probe skeleton 301 using a tool, and then the cobalt-based amorphous strip 303 is bonded to the magnetic core slot 3011 of the magnetic probe skeleton 301 using solid glue, and the cobalt-based amorphous strip 303 is wrapped and fixed with a high-temperature tape 304, and finally the coil 305 is wound on the magnetic probe skeleton 301. Therefore, the current magnetic probe assembly 30 has a complicated assembly process, and the pin head is easily broken when the pin 302 is pressed in, and the magnetic probe assembly 30 needs to be sent to an external supplier to wind the coil 305, and the flatness of the coil 305 is difficult to control, resulting in poor consistency of other related parameters such as inductance. Please refer to Figure 5 and Figure 7 As shown, the material of the amorphous material body 31 of this embodiment is a cobalt-based amorphous alloy, and there is no need to perform cumbersome processes such as pressing the pin 302, bonding the cobalt-based amorphous strip 303, and bundling with the high-temperature tape 304. On the one hand, it can simplify the process and improve production efficiency, and on the other hand, it can also avoid the pin head from breaking when pressing the pin 302. At the same time, the MEMS coil 32 of the magnetic probe assembly 3 of this embodiment is manufactured by micro-electromechanical casting technology, which is mainly divided into two steps in terms of process: coil mold etching and liquid coil metal filling. The liquid alloy coil is flatter and the consistency of parameters such as inductance is better. The cobalt-based amorphous alloy of this embodiment has an inductance of more than 30% higher than that of the current cobalt-based amorphous strip 303 under the conditions of 1kHz and 1A / m, which greatly improves the sensitivity of the magnetic probe assembly 30. The cobalt-based amorphous alloy of this embodiment can also significantly reduce the coercive force of the cobalt-based amorphous alloy through longitudinal magnetic field heat treatment, from 0.95 A / m of the original cobalt-based amorphous alloy to 0.5 A / m, thereby reducing the saturation excitation current of the magnetic probe. Under the same number of coil turns, the saturation excitation current is reduced from 22 mA of the original magnetic probe to 15 mA.

[0050] See also Fig.13 and Fig.14 Also see Figure 5 , Fig.13 is a three-dimensional diagram of the magnetic core assembly of the present application and Fig.144 is a three-dimensional diagram of the first magnetic core group; as shown in the figure, the magnetic core assembly 4 includes a plurality of first magnetic core pieces 43 and a plurality of second magnetic core pieces 44. The plurality of first magnetic core pieces 43 are stacked together to form a first magnetic core group 45. The first magnetic core group 45 has a first notch 451 on one side and a plurality of first slots 452 on the other side. The plurality of first slots 452 are formed by stacking first magnetic core pieces 43 of different lengths. Specifically, a short first magnetic core piece 43 is stacked between two long first magnetic core pieces 43 to form a first slot 452. The plurality of second magnetic core pieces 44 are stacked together to form a second magnetic core group 46. The second magnetic core group 46 has a second notch 461 on one side and a plurality of second slots 462 on the other side. The plurality of second slots 462 are formed by stacking second magnetic core pieces 44 of different lengths. Specifically, a short second magnetic core piece 44 is stacked between two long second magnetic core pieces 44 to form a second slot 462. The first magnetic core group 45 is butted against the second magnetic core group 46. The first slot 451 and the second slot 461 are connected to form the installation slot 411. The first slot 452 and the second slot 462 are inserted into each other. Here, the insertion means that the long second magnetic core 44 is inserted between the two long first magnetic cores 43 and abuts against the short first magnetic core 43, and the long first magnetic core 43 is inserted between the two long second magnetic cores 44 and abuts against the short second magnetic core 44. Please refer to Fig.15 and Fig.16 , Fig.15 The assembly state diagram of the magnetic core component, the winding component and the magnetic probe component of the present application is shown in FIG. Fig.16 It is a side view of the assembly of the magnetic core component, the winding component and the magnetic probe component; as shown in the figure, the magnetic core component 4 of this embodiment is divided into a first magnetic chip group 45 and a second magnetic chip group 46, and the first magnetic chip group 45 and the second magnetic chip group 46 can be assembled by plugging. Fig.17 and Fig.18 , Fig.17 This is a three-dimensional diagram of the current magnetic core assembly and Fig.18 is a three-dimensional diagram of a current magnetic core; as shown in the figure, the current magnetic core assembly 50 requires multiple magnetic cores 501 to be inserted and stacked one by one, usually 12 times, and to prevent the wrong number of magnetic cores 501 from being assembled, the number of magnetic cores 501 needs to be confirmed multiple times after assembly. Therefore, the magnetic core assembly 4 of this embodiment saves time and effort compared to the current magnetic core assembly 50, and is easy to control the number of magnetic cores 501.

[0051] See also Fig.19, which is an exploded view of the current shielding assembly; as shown in the figure, the current shielding assembly 60 is usually composed of a bent shielding sheet 601, a shielding sheet 602, a shielding frame 603 and a shielding ring 604. There are too many parts and components, which are difficult to manage, and the assembly is complicated, time-consuming and labor-intensive. In addition, the components of the current shielding assembly 60 require multiple sets of molds to cooperate with the processing of the shielding set, which increases the cost. Please refer to Fig. 20 , which is a three-dimensional diagram of the iron-based nanocrystalline magnetic shielding sheet of the present application; as shown in the figure, the electromagnetic shielding member 5 of this embodiment uses an iron-based nanocrystalline magnetic shielding sheet, which can not only reduce the number of parts and components, reduce the difficulty of the assembly process, but also does not require mold opening, greatly reducing costs. At the same time, since the thickness of the shielding sheet 602 of the current shielding assembly 60 is usually 0.35 mm, and the thickness of the shielding ring 604 is usually 0.23 mm, and the thickness of the iron-based nanocrystalline magnetic shielding sheet of this embodiment is only 50 μm, the overall weight of the electromagnetic shielding member 5 and the sensor can be greatly reduced. At the same time, the nanocrystalline magnetic shielding sheet of this embodiment adopts a single-layer iron-based nanocrystalline thin strip with a thickness of only 12 μm and an operating frequency of 500 kHz, which is much better than the silicon steel (the material of the various components of the current shielding assembly 60) <10 kHz operating frequency. At the same time, the effective magnetic permeability under 200 kHz conditions is more than 40,000, and the shielding effect is greatly improved compared with the original solution. In addition, the iron-based nanocrystalline magnetic shielding sheet of this embodiment also has the advantages of being closely fitted to the inner wall of the housing 1 and having good adhesion.

[0052] In summary, the present application provides a new type of leakage current sensor for photovoltaic systems. By setting the spiral coil in the spiral groove hole of the axial through hole of the coil substrate and etching the MEMS coil in the amorphous material body, the winding efficiency of the winding assembly and the magnetic probe assembly can be greatly improved, the structure of the leakage current sensor can be reduced, and it is easy to assemble, which meets the requirements of energy-saving and emission-reduction production. At the same time, the spiral coil and MEMS coil of the present application can be prepared by filling liquid alloy, which further solves the problem of winding flatness. At the same time, the resistance of the spiral coil can be adjusted according to the composition of the liquid alloy. The spiral coil has high designability and better consistency of parameters such as inductance. The present application divides the magnetic core assembly into a first magnetic chip group and a second magnetic chip group. The first magnetic chip group and the second magnetic chip group can be assembled by plugging. Compared with the current magnetic core assembly, it saves time and effort, and is easy to control the number of magnetic chips. At the same time, the present application replaces the current complex shielding assembly structure with an iron-based nanocrystalline magnetic shielding sheet, which can not only reduce the number of parts and components, reduce the difficulty of the assembly process, but also does not require mold opening, greatly reducing costs.

[0053] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0054] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A new leakage current sensor applied to photovoltaic system, characterized in that: include: case; A winding assembly is arranged in the shell, the winding assembly includes a coil base and a spiral coil, the coil base has a through hole and a spiral slot hole located in the through hole in the axial direction, the spiral coil is arranged in the spiral slot hole, the coil base includes an upper base and a lower base, a first through slot is provided on a side of the upper base adjacent to the lower base, a second through slot is provided on a side of the lower base adjacent to the upper base, the first through slot and the second through slot are connected to form the through hole, the spiral slot hole is located between the first through slot and the second through slot, the material of the upper base is a silicon wafer, and the first through slot and the spiral slot hole are provided on one side of the upper base by a photolithography process, the material of the lower base is a silicon wafer, and the second through slot and the spiral slot hole are provided on the lower base by a photolithography process, the material of the spiral coil is a liquid alloy, and the liquid alloy is filled in the spiral slot holes of the first through slot and the second through slot by a micro casting forming process to form a liquid alloy spiral coil; A magnetic probe assembly is arranged in the through hole, wherein the magnetic probe assembly comprises an amorphous material body with low saturation magnetic flux and a MEMS coil, wherein the MEMS coil is etched in the amorphous material body, and the material of the amorphous material body is a cobalt-based amorphous alloy; A magnetic core component is disposed in the housing, the magnetic core component has a first side and a second side opposite to each other, the first side has a mounting groove, a portion of the first side and the mounting groove are located in the through hole, the magnetic probe component is located in the mounting groove, and the second side is located outside the through hole; The electromagnetic shielding component is arranged on the inner wall of the shell.

2. The novel leakage current sensor according to claim 1 is characterized in that: The shell comprises an upper shell and a lower shell, wherein the upper shell covers the lower shell, and the winding assembly, the magnetic probe assembly and the magnetic core assembly are located between the upper shell and the lower shell.

3. The novel leakage current sensor according to claim 1 is characterized in that: The liquid alloy spiral coil is a single-layer structure or a double-layer serial structure.

4. The novel leakage current sensor according to claim 1 is characterized in that: The magnetic core component includes a plurality of first magnetic chips and a plurality of second magnetic chips, wherein the plurality of first magnetic chips are stacked together to form a first magnetic chip group, wherein the first magnetic chip group has a first notch on one side and a plurality of first slots on the other side, wherein the plurality of first slots are formed by stacking first magnetic chips of different lengths, and the plurality of second magnetic chips are stacked together to form a second magnetic chip group, wherein the second magnetic chip group has a second notch on one side and a plurality of second slots on the other side, wherein the plurality of second slots are formed by stacking second magnetic chips of different lengths, wherein the first magnetic chip group is docked with the second magnetic chip group, wherein the first notch is docked with the second notch to form the mounting groove, and the first slot is inserted into the second slot.

5. The novel leakage current sensor according to claim 1 is characterized in that: The electromagnetic shielding component uses an iron-based nanocrystalline magnetic shielding sheet.

6. The novel leakage current sensor according to claim 1 is characterized in that: It further includes: pins and a PCB board, the pins are connected to the PCB board, and the PCB board is electrically connected to the winding assembly and the magnetic probe assembly.

7. The novel leakage current sensor according to claim 6 is characterized in that: An integral conversion circuit is provided on the PCB board, and the integral conversion circuit is used to convert the PWM signal output by the magnetic probe assembly into a voltage signal, and convert it into an output current after amplification and output it to the winding assembly, and in the zero magnetic flux state, the formula I=Iout*N is satisfied, wherein I is the input current, N is the number of turns of the winding assembly, and Iout is the output current after the voltage signal is amplified.

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