Device structure, sensor and processing system with DC and arc current detection

Abstract

The present invention discloses a device structure, sensor and system with direct current and arc current detection, the device structure comprises: a conductor; a first magnetic core, a first gap of a preset size is designed in an open loop on a preset side wall, and the conductor is wound around its surface to detect the arc current; a second magnetic core is stacked with the first magnetic core, and a second gap is designed in an open loop on a side wall stacked with the preset side wall, and the second gap is at least partially connected with the first gap; a PCB board comprises a first part and a second part, the second part is clamped in the two side walls of the second gap, and the first part is in contact with the outer surface of the side wall where the second gap is located; a current detection chip is located on the upper surface or the lower surface of the second part, and is used to detect direct current; a signal processing module is connected to the first magnetic core and the current detection chip, and is used to process and output the detected arc current and direct current; the surface of the conductor is insulated from the outer surface of the first magnetic core. This scheme can realize direct current and arc current detection at the same time.

Description

Technical Field

[0001] The present invention relates to the field of string current and arc current detection equipment, and in particular to a device structure, a sensor and a processing system capable of detecting direct current and arc current. Background Art

[0002] When photovoltaic inverter panels are used outdoors for a long time, the cables may age and the contact may be poor, which may cause arcs in normal use. In severe cases, high temperature fires may occur, which poses a great safety hazard. Arc detection can timely discover and eliminate safety hazards, effectively avoiding the occurrence of the above safety hazards. Therefore, arc detection of photovoltaic inverter panels has become a mainstream trend. In addition to detecting arc current, DC signal detection is also essential.

[0003] The detection principle of the arc detection device in the prior art solution is similar to the application of mutual inductor, see Figure 1 As shown, the larger current on the primary side of the transformer is converted into a smaller current on the secondary side based on the principle of electromagnetic induction, and the current sensed by the secondary winding is sampled to the signal processing module through a series resistor, and the signal processing module restores the original current through the rated mutual inductance ratio of the transformer. Among them, the mutual inductance ratio of the transformer is the ratio of the rated current of the primary winding N1 on the primary side to the secondary winding N2 on the secondary side, or it can be approximately expressed as the ratio of the number of turns of the primary winding coil on the primary side to the secondary winding coil on the secondary side, and the secondary side adopts a closed magnetic ring setting.

[0004] The device diagram of the detection device used in the DC current detection part is shown in 2a, and the circuit diagram is shown in Figure 2b As shown, the primary current passes through the magnetic ring, and the magnetic ring generates a magnetic field according to electromagnetic induction. The sensor chip in the gap of the magnetic ring converts the induced magnetic field into a voltage signal output for subsequent detection.

[0005] In the prior art, the device for detecting direct current and the device for detecting arc current are independent devices, which results in a technical problem of large volume and inconvenience for board-mounted installation.

[0006] Therefore, the existing technical solutions lack a detection device that is small in size and can simultaneously detect arc current and DC current. Summary of the invention

[0007] Therefore, in order to solve the technical problem that the existing technical solutions lack a detection device with a small size that can simultaneously realize arc current detection and DC current detection, the present invention provides a device structure, sensor and processing system with DC and arc current detection.

[0008] In a first aspect, a device structure with DC and arc current detection is provided according to an embodiment of the present invention, comprising:

[0009] wire;

[0010] The first magnetic core is open-loop designed with a first gap of a preset size on a preset side wall, and the wire is wound on the surface of the first magnetic core for detecting the arc current;

[0011] A second magnetic core is stacked with the first magnetic core, and a second gap is designed in an open loop on the side wall stacked with the preset side wall, and the second gap is at least partially connected with the first gap;

[0012] A PCB board, comprising a first part and a second part, wherein the second part is clamped in two side walls of the second slit, and the first part abuts against an outer surface of the side wall where the second slit is located;

[0013] A current detection chip, located on the upper surface or the lower surface of the second part, for detecting a direct current;

[0014] The signal processing module includes a first processing unit and a second processing unit, wherein the first processing unit is connected to the first magnetic core and is used to process and output the arc current detected by the first magnetic core; the second processing unit is connected to the current detection chip and is used to process and output the DC current detected by the current detection chip;

[0015] A surface of the conductive wire is insulated from an outer surface of the first magnetic core.

[0016] Preferably,

[0017] The surface of the conductive wire is insulated from the outer surface of the first magnetic core, comprising:

[0018] The surface of the wire is subjected to insulation treatment; and / or

[0019] The outer surface of the first magnetic core is subjected to insulation treatment.

[0020] Preferably,

[0021] The insulation treatment is a varnish dipping process.

[0022] Preferably, the distance between the current detection chip and the bottom of the second gap is H / 3-2H / 3;

[0023] Wherein, H is the height of the second gap.

[0024] Preferably, it also includes:

[0025] A fixing assembly, comprising a bottom plate and a fixing pin group fixed on one surface of the bottom plate, connected to a surface of the first part of the PCB board through another surface of the bottom plate;

[0026] Wherein, two ends of the wire are respectively connected to one of the fixing pins.

[0027] Preferably, the two ends of the wire are respectively connected to one of the fixing pins by welding.

[0028] In a second aspect, an embodiment of the present invention provides a sensor including a device structure with DC and arc current detection as described in any one of the above items, further comprising:

[0029] The shell comprises an inner wall and an outer wall, and a gap is arranged between the inner wall and the outer wall to accommodate the first magnetic core wound with the wire.

[0030] Preferably, a fixing piece is provided on the inner wall on one side close to the first gap or the second gap.

[0031] The fixing member abuts against preset side walls on both sides of the first gap or the second gap, and is used to fix the first magnetic core or the second magnetic core.

[0032] Preferably, the fixing member comprises a first fixing plate and a second fixing plate, and the first fixing plate and the second fixing plate are respectively in contact with side walls on both sides of the first slit or the second slit.

[0033] In a third aspect, according to an embodiment of the present invention, there is provided a processing system having direct current detection and arc current detection functions, comprising any of the above device structures, and further comprising:

[0034] A first ADC signal acquisition module is connected to the first processing unit corresponding to the first magnetic core and is used to acquire the arc current signal processed by the first processing unit;

[0035] A second ADC signal acquisition module is connected to the second processing unit corresponding to the current detection chip and is used to acquire the DC current signal processed by the second processing unit;

[0036] A first judgment module, connected to the first ADC signal acquisition module, is used to judge whether the arc current collected by the first ADC signal acquisition module meets a first preset condition;

[0037] A second judgment module, connected to the second ADC signal acquisition module, is used to judge whether the DC current collected by the second ADC signal acquisition module meets a second preset condition;

[0038] A first warning module, connected to the first judgment module, is used to issue a first warning message if the arc current collected by the first ADC signal collection module meets a first preset condition;

[0039] The second warning module and the second judgment module are used to issue a second warning message if the direct current collected by the second ADC signal collection module meets the second preset condition.

[0040] The present invention can achieve the following technical effects:

[0041] 1. The device structure, sensor and system with DC and arc current detection provided by this solution overcome the defect that there is no device that can detect DC current and arc current at the same time in the prior art solution; and in this solution, the DC current detection chip and the arc current detection chip are respectively attached to the opposite surfaces of the second part of the PCB board, so that the sensor with both DC current detection capabilities and arc current detection capabilities is smaller in size and convenient for on-board installation.

[0042] 2. The core has low material requirements and uses ferrite, which is inexpensive, ensuring lower costs and improving convenience for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 It is a structural schematic diagram of a mutual inductor in the prior art solution;

[0045] Figure 2a It is a schematic diagram of a DC current detection device in the prior art solution;

[0046] Figure 2b It is an internal circuit diagram of a DC current detection device in the prior art solution;

[0047] Figure 3 , Figure 4 They are schematic diagrams of device structures with direct current and arc current detection provided by embodiments of the present invention;

[0048] Figure 5 A diagram showing the relationship between the DC current detected by the current detection chip and the output voltage of the device structure in a specific embodiment of the present invention;

[0049] Figure 6 A schematic diagram of a sensor with DC and arc current detection provided by an embodiment of the present invention;

[0050] Figure 7A module diagram of a system with DC and arc current detection provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0051] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] In the description of the present invention, 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 invention 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 invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0053] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can also be the internal connection of two components, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0055] Example 1

[0056] In order to solve the technical problem that the prior art lacks a detection device with a small volume and capable of simultaneously realizing DC and arc current detection, the embodiment of the present invention provides a device structure with DC and arc current detection, see Figure 3 As shown, including:

[0057] Wire 31;

[0058] The first magnetic core 32 is designed with a first gap of a preset size in an open loop on a preset side wall, and the wire is wound on its surface for detecting the arc current;

[0059] A second magnetic core 33 is stacked with the first magnetic core, and has a second gap designed in an open loop on the side wall stacked with the preset side wall, and the second gap is at least partially connected with the first gap;

[0060] The PCB board 34 includes a first portion 341 and a second portion 342, wherein the second portion 342 is clamped in two side walls of the second slit, and the first portion abuts against an outer surface of the side wall where the second slit is located;

[0061] A current detection chip 35, located on the upper surface or the lower surface of the second part, for detecting a direct current;

[0062] The signal processing module includes a first processing unit and a second processing unit, wherein the first processing unit is connected to the first magnetic core and is used to process and output the arc current signal detected by the first magnetic core, and the second processing unit is connected to the current detection chip and is used to process and output the DC current detected by the current detection chip;

[0063] A surface of the conductive wire is insulated from an outer surface of the first magnetic core.

[0064] In an embodiment of the present invention, the current detection chip and the first magnetic core can be soldered on the PCB board through solder paste using the SMT process, and the first processing unit can be located on the current detection chip or on the PCB board. Similarly, the second processing unit can be located on the PCB board or on the first magnetic core.

[0065] In the embodiment of the present invention, the surface of the wire 31 is insulated from the surface of the first magnetic core 32 to avoid short circuit due to the circuit conduction between the surface of the wire 31 and the surface of the first magnetic core 32 during the wire power-on process, thereby effectively ensuring personal and property safety.

[0066] In the embodiment of the present invention, the sizes of the first gap and the second gap can be set according to actual needs. The size of the first gap is set according to the range of arc current to be sensed, and the size of the second gap is set according to the range of DC current to be detected. That is, the size of the second gap can be set to be the same as the size of the first gap, or the sizes of the two can be set to be different, and there is no necessary size relationship between the two.

[0067] In the device structure provided in the embodiment of the present invention, during operation, the wire wound around the first magnetic core is preferably connected to the PCB board by welding to complete arc current detection.

[0068] The device structure provided by the embodiment of the present invention has at least the following beneficial effects:

[0069] 1. The device structure, sensor and system with DC and arc current detection provided by this solution overcome the defect that there is no device that can detect DC current and arc current at the same time in the prior art solution; and in this solution, the DC current detection chip and the arc current detection chip are respectively attached to the opposite surfaces of the second part of the PCB board, so that the sensor with both DC current detection capabilities and arc current detection capabilities is smaller in size and convenient for on-board installation.

[0070] 2. The core has low material requirements and uses ferrite, which is inexpensive, ensuring lower costs and improving convenience for mass production.

[0071] In the embodiment of the present invention, the surface of the conductive wire 31 is insulated from the outer surface of the first magnetic core 32, including:

[0072] The surface of the wire 31 is subjected to insulation treatment; and / or

[0073] The outer surface of the first magnetic core 32 is insulated.

[0074] In the embodiment of the present invention, in order to ensure that the surface of the wire 31 is insulated from the outer surface of the first magnetic core 32, at least one of the surface of the wire 31 and the outer surface of the first magnetic core 32 is insulated. To be on the safe side, both of them can be insulated, thereby effectively avoiding the occurrence of a short circuit caused by the electrical connection between the two when the wire is turned on.

[0075] Furthermore, in an embodiment of the present invention, the insulation treatment may be a paint dipping process, that is, the surface of the wire 31 or the outer surface of the first magnetic core 32 is subjected to a paint dipping (spray painting) treatment, so that an insulating layer is attached to the surface of the wire 31 or the outer surface of the first magnetic core 32.

[0076] In the embodiment of the present invention, the distance between the current detection chip 35 and the bottom of the second gap is H / 3-2H / 3, wherein H is the height of the second gap.

[0077] In the embodiment of the present invention, the current detection chip 35 is located in the middle of the vertical plane of the second gap, such as being located at a distance between H / 3 and 2H / 3 from the bottom, such as being at a distance of H / 3, H / 2 or 2H / 3 from the bottom of the second gap.

[0078] The device structure provided in the embodiment of the present invention may further include:

[0079] The fixing assembly 36 includes a bottom plate 361 and a fixing pin group 362 fixed on one surface of the bottom plate 361, and the other surface of the bottom plate 361 is connected to one surface of the first part 341 of the PCB board;

[0080] Wherein, two ends of the wire 31 are respectively connected to one of the fixing pins.

[0081] In an embodiment of the present invention, both ends of the wire are respectively connected to one of the fixed pins, and in an embodiment of the present invention, the fixed pin can also be used as an output signal pin. As shown in the figure, the fixed pin 3621 can be used as the positive output terminal of the first magnetic core (arcing current detection magnetic core); the fixed pin 3622 can be used as the external power supply access terminal of the device structure provided by the present invention; the fixed pin 3623 can also be used as the grounding terminal of the device structure provided by the present invention; the fixed pin 3624 can also be used as the output terminal of the device structure; the fixed pin 3625 can also be used as the negative output terminal of the first magnetic core (arcing current detection magnetic core).

[0082] Furthermore, in an embodiment of the present invention, the two ends of the wire are respectively connected to one of the fixing pins by welding.

[0083] The first magnetic core and the second magnetic core in the embodiment of the present invention can be made of ferrite material, which has low material requirements and effectively avoids the problem of large volume caused by using nano materials in the existing technical solutions. Ferrite material is low in price, which provides favorable conditions for mass production.

[0084] In the embodiment of the present invention, the apertures of the first magnetic core and the second magnetic core are preferably rectangular, and preferably, the apertures of the two are of the same shape and size.

[0085] In an embodiment of the present invention, when the test wire (primary current line) passes through the apertures of the first magnetic core and the second magnetic core and is turned on, the current detection chip senses the current of the test wire and converts it into a magnetic field. The current detection chip located in the second gap senses the primary current to generate a magnetic field, which is then converted into a voltage signal output through a conditioning circuit. It is converted into a primary current signal through proportional transformation. The AC signal is filtered out by a filtering circuit, so the DC detection part of the device structure will not sense the high-frequency arcing signal, thereby outputting a DC component. The first magnetic core senses the high-frequency arcing signal through the magnetic ring, and the DC signal will not be captured by the first magnetic core.

[0086] As follows, a specific embodiment is given to illustrate:

[0087] By using the device structure with DC and arc current detection provided by the embodiment of the present invention, the primary arc current can be simulated between the current frequency of 5kHz and 100kHz, such as adding 10mA 10kHz AC current to the induced 10A DC current (primary current), thereby detecting the arc current signal detected by the first magnetic core and the DC current signal detected by the DC detection chip; for example, the output of the DC detection chip and the output of the device structure can be detected, see Figure 5 As shown, in Figure 5In the figure, the horizontal axis is the DC current detected by the current detection chip, and the vertical axis is the output of the device structure with DC and arc current detection. It can be seen that the DC current corresponding to the device structure outputting 4.5V is 25A. Since the device structure has a bias voltage, if the bias voltage of the device structure is 2.5V, the output voltage of the device structure corresponding to the DC current of 25A is 2V.

[0088] Example 2

[0089] The embodiment of the present invention further provides a sensor with DC and arc current detection, including the device structure with DC and arc current detection in the previous embodiment, see Figure 6 As shown, it also includes:

[0090] The housing 37 includes an inner wall 371 and an outer wall 372 , and a gap is provided between the inner wall 371 and the outer wall 372 to accommodate the first magnetic core wound with the wire.

[0091] In an embodiment of the present invention, a first magnetic core wound with a wire is placed between the inner wall and the outer wall of the shell to form a sensor with DC and arc current detection. The sensor can be fixed by a fixing member where DC and arc current detection are required.

[0092] In an embodiment of the present invention, a fixing member is provided on the inner wall near the first gap or the second gap.

[0093] The fixing member abuts against preset side walls on both sides of the first gap or the second gap, and is used to fix the first magnetic core or the second magnetic core.

[0094] Further, in an embodiment of the present invention, the fixing member includes a first fixing plate and a second fixing plate, and the first fixing plate and the second fixing plate are respectively abutted against side walls on both sides of the first slit or the second slit.

[0095] It is pointed out here that the contents disclosed in the previous embodiment regarding the device structure with DC and arc current detection are also applicable in the embodiment of the present invention, and will not be described here in order to avoid repetition.

[0096] The sensor with direct current and arc current detection provided by the embodiment of the present invention

[0097] 1. The sensor with DC and arc current detection provided by this solution overcomes the defect that there is no device that can detect DC current and arc current at the same time in the prior art solution; and in this solution, the DC current detection chip and the arc current detection chip are respectively attached to the opposite surfaces of the second part of the PCB board, so that the sensor with both DC current detection capabilities and arc current detection capabilities is smaller in size and convenient for on-board installation.

[0098] 2. The first magnetic core and the second magnetic core do not have high requirements on materials, and ferrite is used, which is low in price, ensuring low costs and improving convenient conditions for mass production.

[0099] Example 3

[0100] The embodiment of the present invention also provides a system with DC current detection and arc current detection functions, see Figure 7 As shown, the device structure 70 with DC and arc current detection in the above embodiment also includes:

[0101] A first ADC signal acquisition module 71, connected to the first processing unit corresponding to the first magnetic core, and used to acquire the arc current signal processed by the first processing unit;

[0102] A second ADC signal acquisition module 72, connected to the second processing unit corresponding to the current detection chip, for acquiring the DC current signal processed by the second processing unit;

[0103] A first judgment module 73, connected to the first ADC signal acquisition module, is used to judge whether the arc current collected by the first ADC signal acquisition module meets a first preset condition;

[0104] A second judgment module 74, connected to the second ADC signal acquisition module, is used to judge whether the DC current collected by the second ADC signal acquisition module meets the second preset condition;

[0105] The first warning module 75 is connected to the first judgment module 83 and is used to issue a first warning message if the arc current collected by the first ADC signal collection module meets the first preset condition;

[0106] The second warning module 76 and the second judgment module 84 are configured to issue a second warning message if the DC current collected by the second ADC signal collection module meets a second preset condition.

[0107] The system with DC and arc current detection functions provided by the embodiment of the present invention can determine whether the corresponding preset conditions for issuing warning information are met based on the DC signal and arc current signal detected by the device structure with DC and arc current detection provided by the above embodiment. If met, the first warning information is issued for the arc current signal that meets the first preset condition, and / or the second warning information is issued for the DC signal that meets the second preset condition. The DC current and the arc current can be detected at the same time. The defect that there is no device that can detect the DC current and the arc current at the same time in the prior art solution is effectively overcome.

[0108] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A device with DC and arc current detection, characterized in that: include: wire; The first magnetic core is open-loop designed with a first gap of a preset size on a preset side wall, and the wire is wound on the surface of the first magnetic core for detecting the arc current; A second magnetic core is stacked with the first magnetic core, and a second gap is designed in an open loop on the side wall stacked with the preset side wall, and the second gap is at least partially connected with the first gap; A PCB board, comprising a first part and a second part, wherein the second part is clamped in two side walls of the second slit, and the first part abuts against an outer surface of the side wall where the second slit is located; A current detection chip, located on the upper surface or the lower surface of the second part, for detecting a direct current; The signal processing module includes a first processing unit and a second processing unit, wherein the first processing unit is connected to the first magnetic core and is used to process and output the arc current detected by the first magnetic core; the second processing unit is connected to the current detection chip and is used to process and output the DC current detected by the current detection chip; A surface of the conductive wire is insulated from an outer surface of the first magnetic core.

2. The device according to claim 1, characterized in that The surface of the conductive wire is insulated from the outer surface of the first magnetic core, comprising: The surface of the wire is subjected to insulation treatment; and / or The outer surface of the first magnetic core is subjected to insulation treatment.

3. The device according to claim 2, characterized in that The insulation treatment is a varnish dipping process.

4. The device according to claim 1, characterized in that The distance between the current detection chip and the bottom of the second gap is H / 3-2H / 3; Wherein, H is the height of the second gap.

5. The device according to claim 1, characterized in that Also includes: A fixing assembly, comprising a bottom plate and a fixing pin group fixed on one surface of the bottom plate, wherein the other surface of the bottom plate is connected to a surface of the first part of the PCB board; Wherein, two ends of the wire are respectively connected to one of the fixing pins.

6. The device according to claim 5, characterized in that The two ends of the wire are respectively connected to one of the fixing pins by welding.

7. A sensor comprising a device structure having direct current and arc current detection as claimed in any one of claims 1 to 6, characterized in that: Also includes: The shell comprises an inner wall and an outer wall, and a gap is arranged between the inner wall and the outer wall to accommodate the first magnetic core wound with the wire.

8. The sensor according to claim 7, characterized in that A fixing piece is provided on the inner wall near the first gap or the second gap. The fixing member abuts against preset side walls on both sides of the first gap or the second gap, and is used to fix the first magnetic core or the second magnetic core.

9. The sensor according to claim 8, characterized in that The fixing member includes a first fixing plate and a second fixing plate, and the first fixing plate and the second fixing plate are respectively in contact with the side walls at both sides of the first gap or the second gap.

10. A system with DC current detection and arc current detection functions, characterized in that: The device structure according to any one of claims 1 to 8 further comprises: A first ADC signal acquisition module is connected to the first processing unit corresponding to the first magnetic core and is used to acquire the arc current signal processed by the first processing unit; A second ADC signal acquisition module, connected to the second processing unit corresponding to the current detection chip, and used to acquire the DC current signal processed by the second processing unit; A first judgment module, connected to the first ADC signal acquisition module, is used to judge whether the arc current collected by the first ADC signal acquisition module meets a first preset condition; A second judgment module, connected to the second ADC signal acquisition module, is used to judge whether the DC current collected by the second ADC signal acquisition module meets a second preset condition; A first warning module, connected to the first judgment module, is used to issue a first warning message if the arc current collected by the first ADC signal collection module meets a first preset condition; A second warning module, connected to the second judgment module, is used to issue a second warning message if the DC current collected by the second ADC signal collection module meets a second preset condition; The processing module includes a first processing unit and a second processing unit.

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