A sensor capable of simultaneously detecting direct current and arc current

Abstract

The present application discloses a sensor capable of simultaneously detecting direct current and arc current, comprising: a shell, comprising an inner wall and an outer wall, a gap being arranged between the inner wall and the outer wall; a magnetic core, being located in the gap, and having an open-loop gap of a preset size on a preset side wall; a PCB board, comprising a first part and a second part, the second part being connected to the first part, the second part being embedded between the two side walls of the gap, the first part being located outside the magnetic core and abutting against the side where the gap is located; a direct current detection chip, being attached to the first surface of the second part; an arc current detection chip, being attached to the second surface of the second part; a signal processing module, being respectively connected to the direct current detection chip and the arc current detection chip, and processing and outputting the detected direct current signal and arc current signal; the present solution can simultaneously detect direct current and arc current, and has a small volume, which is conducive to on-board installation.

Description

Technical Field

[0001] The present application relates to the field of string current and arc current detection equipment, and specifically to a sensor that can simultaneously detect 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 being unfavorable for on-board 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.

[0007] Application Contents

[0008] Therefore, in order to solve the technical problem that the existing technical solutions lack a detection device with a small size that can simultaneously detect arc current and DC current, the present application provides a sensor that can simultaneously detect DC and arc current.

[0009] According to an embodiment of the present application, a sensor capable of simultaneously detecting direct current and arc current is provided, comprising:

[0010] The outer shell comprises an inner wall and an outer wall, and a gap is arranged between the inner wall and the outer wall;

[0011] A magnetic core is located in the gap and has a gap of a preset size in an open loop design on a preset side wall;

[0012] A PCB board, comprising a first part and a second part, wherein the second part is connected to the first part and embedded between two side walls of the gap, and the first part is located outside the magnetic core and abuts against the side surface where the gap is located;

[0013] a direct current detection chip, attached to the first surface of the second portion, for detecting direct current;

[0014] An arc current detection chip, attached to the second surface of the second part, for detecting the arc current;

[0015] A signal processing module, connected to the DC current detection chip and the arc current detection chip, respectively, to process and output the detected DC current signal and arc current signal;

[0016] The second surface is opposite to the first surface.

[0017] Preferably, the side wall of the gap is provided with a first flange protruding outward, and a first recess matching the first flange is provided at a corresponding position of the first part of the PCB board, so that the first part of the PCB board is tightly fitted with the preset side wall through the matching of the first flange and the first recess.

[0018] Preferably, a fixing piece is provided on the inner wall on the side close to the gap of the magnetic core.

[0019] The fixing member abuts against the preset side edges of the two side walls of the gap to fix the magnetic core.

[0020] 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 gap.

[0021] Preferably, the DC current detection chip and the arc current detection chip are both full-bridge chips.

[0022] Preferably, in the processing module, the circuit structure of the processing unit corresponding to the DC current detection chip includes:

[0023] A first magnetic sensor chip consisting of a first resistor, a second resistor, a third resistor and a fourth resistor;

[0024] A first filtering module, including a fifth resistor and a sixth resistor, for filtering an alternating current;

[0025] A first operational amplifier includes a first connection terminal, a second connection terminal, a third connection terminal, a fourth connection terminal and a ground terminal, the third connection terminal is connected to a fifth resistor, the second connection terminal is connected to a sixth resistor, a second capacitor and a seventh resistor connected in parallel are provided at the first connection terminal and the second connection terminal, an eighth resistor and a first capacitor connected in parallel are provided between the fifth resistor and the third connection terminal, and the fourth connection terminal is an output terminal;

[0026] The first resistor and the second resistor are connected in series to form a first resistor group, the third resistor and the fourth resistor are connected in series to form a second resistor group, and the first resistor group and the second resistor group are connected in parallel to form the first magnetic sensor chip; and

[0027] The capacitance value of the first capacitor is the same as the capacitance value of the second capacitor, and the resistance value of the seventh resistor is the same as the resistance value of the eighth resistor.

[0028] Preferably,

[0029] The low-pass frequencies of the first capacitor and the second capacitor are both f1=1 / (2*PI*C1*R7);

[0030] Wherein, C1 is the capacitance value of the first capacitor C1, R7 is the resistance value of the seventh resistor MR1, and PI is the value of pi.

[0031] Preferably, the sensitivity of the first magnetic sensor chip is 0.1mV / V / Gs-0.5mV / V / Gs.

[0032] Preferably, the output voltage V of the DC current detection chip is out1 for:

[0033] V out1 =β1*I1*Sen1*M1+Vref1;

[0034] Wherein, β1 is the amplification factor of the first magnetic sensor chip, I1 is the primary current, Sen1 is the sensitivity of the first magnetic sensor chip, M1 is the magnetic field generated by each 1A DC current, and Vref1 is the bias voltage of the first magnetic sensor chip.

[0035] Preferably, in the processing module, the circuit structure of the processing unit corresponding to the arc current detection chip includes:

[0036] a second magnetic sensor chip consisting of a ninth resistor, a tenth resistor, an eleventh resistor and a twelfth resistor;

[0037] A second filtering module, including a thirteenth resistor, a fourteenth resistor, a fifth capacitor and a sixth capacitor, for filtering a DC current;

[0038] A second operational amplifier includes a first connection terminal, a second connection terminal, a third connection terminal, a fourth connection terminal and a ground terminal, the third connection terminal is connected to a thirteenth resistor, the second connection terminal is connected to a fourteenth resistor, a fourth capacitor and a fifteenth resistor connected in parallel are provided at the first connection terminal and the second connection terminal, a sixteenth resistor and a third capacitor connected in parallel are provided between the thirteenth resistor and the third connection terminal, and the fourth connection terminal is an output terminal;

[0039] The ninth resistor and the tenth resistor are connected in series to form a third resistor group, the eleventh resistor and the twelfth resistor are connected in series to form a fourth resistor group, and the third resistor group and the fourth resistor group are connected in parallel to form the second magnetic sensor chip; and

[0040] The resistance value of the thirteenth resistor is the same as the resistance value of the fourteenth resistor, and the resistance value of the fifteenth resistor is the same as the resistance value of the sixteenth resistor.

[0041] Preferably, the frequencies of the third capacitor and the fourth capacitor are both: f2=1 / (2*PI*C5*R 13 );

[0042] Where C5 is the capacitance value of the fifth capacitor, R 13 is the resistance value of the thirteenth resistor.

[0043] Preferably, the sensitivity of the second magnetic sensor chip is 2mV / V / Gs-5mV / V / Gs.

[0044] Preferably, the output voltage V of the arc current detection chip is out2 for:

[0045] V out2 =β2*I2*Sen2*M2+Vref2;

[0046] Among them, β2 is the amplification factor of the second magnetic sensor chip, I2 is the primary current, Sen2 is the sensitivity of the first magnetic sensor chip, M2 is the magnetic field generated by each 1A DC current, and Vref2 is the bias voltage of the second magnetic sensor chip.

[0047] Preferably, the sensor capable of simultaneously detecting direct current and arc current further comprises:

[0048] The fixing component comprises a bottom plate and fixing pins fixed on one surface of the bottom plate, and is connected with one surface of the first part of the PCB board through the other surface of the bottom plate.

[0049] This application can achieve the following technical effects:

[0050] 1. The core is designed as an open loop with a preset gap, which improves the saturation of the core, so that the arc current sensing device can still sense the AC arc current when it senses a large DC current, effectively ensuring that the arc current sensing device has a high sensing capability.

[0051] 2. The sensor that can simultaneously detect DC current and arc current provided by this solution overcomes the defect that there is no device that can simultaneously detect DC current and arc current 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 relative 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.

[0052] 3. The core has low requirements on materials and uses ferrite, which is inexpensive, ensuring lower costs and improving convenience for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the specific implementation methods of the present application 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 application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0054] Figure 1 It is a schematic diagram of the mechanism of the mutual inductor in the prior art solution;

[0055] Figure 2a It is a schematic diagram of a DC current detection device in the prior art solution;

[0056] Figure 2b It is an internal circuit diagram of a DC current detection device in the prior art solution;

[0057] Figure 3 , Figure 4 All of them are schematic diagrams of sensors capable of simultaneously detecting direct current and arc current provided in embodiments of the present application;

[0058] Figure 5 A circuit diagram corresponding to a DC current detection chip in a sensor capable of simultaneously detecting DC current and arc current provided in an embodiment of the present application;

[0059] Figure 6 A graph showing the relationship between the output voltage of the DC current detection chip provided in an embodiment of the present application and the induced magnetic field;

[0060] Figure 7A circuit diagram corresponding to an arc current detection chip in a sensor capable of simultaneously detecting direct current and arc current provided in an embodiment of the present application;

[0061] Figure 8 A graph showing the relationship between the output voltage of the arc current detection chip provided in an embodiment of the present application and the induced magnetic field;

[0062] Figure 9a A diagram showing the relationship between the output voltage of the first magnetic sensor chip and the detected DC current in a specific embodiment of the present application;

[0063] Figure 9b A graph showing the relationship between the output voltage of the second magnetic sensor chip and the detected arc current in a specific embodiment of the present application;

[0064] Fig.10 A relationship diagram between the bandwidth and frequency of a sensor capable of simultaneously detecting DC current and arc current provided in an embodiment of the present application. DETAILED DESCRIPTION

[0065] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0066] 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.

[0067] In the description of this application, 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 this application can be understood according to specific circumstances.

[0068] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0069] Example 1

[0070] The present application embodiment provides a sensor that can detect DC current and arc current at the same time. Figure 3 and Figure 4 As shown, it includes a housing 31, a magnetic core 32, a PCB board 33, a DC current detection chip 34, an arc current detection chip 35 and a signal processing module.

[0071] The housing 31 includes an inner wall 311 and an outer wall 312, and a gap is provided between the inner wall 311 and the outer wall 312; the gap is used to accommodate the magnetic core;

[0072] The magnetic core 32 is located in the gap, and a gap 321 of a preset size is designed in an open loop on a preset side wall of the magnetic core;

[0073] The PCB board 33 includes a first part 331 and a second part 332. The second part 332 is connected to the first part 331. The second part 332 is embedded between the two side walls of the gap 321. The first part 331 is located outside the magnetic core 32 and abuts against the side where the gap 321 is located; the two side edges of the second part respectively abut against the two side walls of the gap.

[0074] A direct current detection chip 34, attached to the first surface of the second portion 332, for detecting direct current;

[0075] An arc current detection chip 35, attached to the second surface of the second portion 332, for detecting the arc current;

[0076] The signal processing module is connected to the DC current detection chip 34 and the arc current detection chip 35 respectively, and processes and outputs the detected DC current signal and arc current signal. It is pointed out here that the DC current detection chip 34 and the arc current detection chip 35 can both adopt SMT technology and be soldered on the PCB board through solder paste, and the signal processing module can be set on the PCB board, or the processing unit corresponding to the DC current detection chip 34 can be set on the DC detection chip, and the processing unit corresponding to the arc current detection chip 35 can be set on the arc current detection chip.

[0077] The second surface is opposite to the first surface.

[0078] In an embodiment of the utility model, the specific size of the preset gap of the open-loop design on the preset side wall is positively correlated with the DC saturation current of the magnetic core. That is, if the DC saturation current of the magnetic core is required to be larger, the size of the open-loop design gap should be correspondingly made larger. In this way, it is ensured that the magnetic core still has the ability to induce AC arc current when inducing a larger DC current.

[0079] In an embodiment of the present application, an open-loop design with a gap of a preset size is provided on a preset side wall of the magnetic core. Compared with a closed-loop design in a conventional solution, the technical solution of an open-loop design with a gap of a preset size improves the saturation of the magnetic core, thereby making it less likely that the sensor will saturate even in the presence of direct current, and the detected arc current can be effectively output.

[0080] The magnetic core in the embodiment of the present application can be made of ferrite material. Compared with the technical solution of using nano-magnetic rings with a larger saturation field to increase the saturation field of the magnetic core, this solution has low requirements on materials, low price, and is easy to mass produce. More importantly, the volume of the magnetic core made of ferrite material with a gap of preset size is much smaller than that of the closed magnetic core made of nano-material under the same saturation field. Therefore, the smaller volume of the sensor can be effectively guaranteed, which greatly facilitates on-board installation.

[0081] In the embodiment of the present application, there is no specific restriction on the material of the shell, and it can be modified and manufactured according to actual needs.

[0082] In the embodiment of the present application, the DC current detection chip 34 and the arc current detection chip 35 are attached to the opposite surfaces of the second part located in the gap, so that the sensor can detect DC current and arc current at the same time, effectively ensuring that the sensor provided by the present solution is small in size and provides convenient conditions for on-board installation.

[0083] In an embodiment of the present application, a first flange protruding outward is provided on the side wall of the gap, and a first recess matching the first flange is provided at a corresponding position of the first part of the PCB board. The first flange matches the first recess so that the first part of the PCB board fits tightly with the preset side wall.

[0084] In the embodiment of the present application, a fixing piece is provided on the inner wall on the side close to the gap of the magnetic core.

[0085] The fixing member abuts against the preset side edges of the two side walls of the gap to fix the magnetic core.

[0086] In the embodiment of the present application, 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 on both sides of the gap.

[0087] In the embodiment of the present application, the DC current detection chip and the arc current detection chip are both full-bridge chips.

[0088] Further, see Figure 5 As shown, the circuit structure of the processing unit corresponding to the DC current detection chip includes:

[0089] A first magnetic sensor chip 41 composed of a first resistor MR1, a second resistor MR2, a third resistor MR3 and a fourth resistor MR4; the first magnetic sensor chip 41 can be welded on a PCB board; a first filter module 42, including a fifth resistor MR5 and a sixth resistor MR6, for filtering AC current;

[0090] The first operational amplifier 43 includes a first connection terminal P1, a second connection terminal P2, a third connection terminal P3, a fourth connection terminal P4 and a ground terminal, the third connection terminal P3 is connected to the fifth resistor MR5, the second connection terminal P2 is connected to the sixth resistor MR6, a second capacitor C2 and a seventh resistor MR7 connected in parallel are provided between the first connection terminal P1 and the second connection terminal P2, an eighth resistor MR8 and a first capacitor C1 connected in parallel are provided between the fifth resistor MR5 and the third connection terminal P3, and the fourth connection terminal P4 is an output terminal; the first connection terminal P1, the second connection terminal P2, the third connection terminal P3, and the fourth connection terminal P4 of the first operational amplifier 43 can be welded on a PCB board, or can be integrated inside the first magnetic sensor chip, and can be set according to actual needs.

[0091] The first resistor MR1 and the second resistor MR2 are connected in series to form a first resistor group, the third resistor MR3 and the fourth resistor MR4 are connected in series to form a second resistor group, and the first resistor group and the second resistor group are connected in parallel to form the first magnetic sensor chip 41; and

[0092] The capacitance value C1 of the first capacitor is the same as the capacitance value of the second capacitor C2 , and the resistance value of the seventh resistor MR7 is the same as the resistance value of the eighth resistor MR8 .

[0093] In the embodiment of the present application, the first capacitor C1 and the second capacitor C2 are both low-pass filter capacitors.

[0094] Here, a specific example is given to illustrate the working process of the DC current detection chip:

[0095] The primary current line passes through the aperture of the magnetic core 32, and generates a magnetic field M in the preset size gap of the open-loop design on the magnetic core 32. The magnetic core is made of ferrite material. The DC current detection chip can sense the magnetic field M according to the principle of magnetic induction. Since the DC current detection chip is an MR bridge (full bridge) magnetic sensor chip, the resistance value of the DC current detection chip changes according to the changes in the sensed magnetic field, and thus the output voltage of the DC current detection chip changes. Specifically, the relationship between the output voltage of the DC current detection chip and the change in the sensed magnetic field can be found in Figure 6 As shown. Figure 6 In the figure, the horizontal axis is the magnetic field strength sensed by the DC current detection chip, and the vertical axis is the output voltage of the DC current detection chip. It can be seen from the figure that when the magnetic field sensed by the DC current detection chip reaches 200Gs, the output voltage of the DC current detection chip can reach 48mV.

[0096] Furthermore,

[0097] The low-pass frequencies of the first capacitor C1 and the second capacitor C2 are both f1=1 / (2*PI*C1*L7);

[0098] Wherein, C1 is the capacitance value of the first capacitor C1, L7 is the resistance value of the seventh resistor MR7, and PI is the value of pi.

[0099] In the embodiment of the present application, the sensitivity range of the first magnetic sensor chip composed of the first resistor MR1, the second resistor MR2, the third resistor MR3 and the fourth resistor MR4 can be 0.1mV / V / Gs-0.5mV / V / Gs, such as 0.1mV / V / Gs, 0.2mV / V / Gs, 0.3mV / V / Gs, 0.4mV / V / Gs or 0.5mV / V / Gs. The gain β1 of the first magnetic sensor chip is the resistance ratio of the seventh resistor MR7 to the sixth resistor MR6. As a specific embodiment, the magnetic field generated by the primary current corresponds to 5Gs / A. At the same time, the output voltage V of the DC current detection chip out1 for:

[0100] V out1 =β1*I1*Sen1*M1+Vref1;

[0101] Wherein, β1 is the amplification factor of the first magnetic sensor chip, I1 is the primary current, Sen1 is the sensitivity of the first magnetic sensor chip, M1 is the magnetic field generated by each 1A DC current, and Vref1 is the bias voltage of the first magnetic sensor chip.

[0102] In the examples of this application, see Figure 7 As shown, the circuit structure of the processing unit corresponding to the arc current detection chip includes:

[0103] A second magnetic sensor chip 61 composed of a ninth resistor MR9, a tenth resistor MR10, an eleventh resistor MR11 and a twelfth resistor MR12; the second magnetic sensor chip 61 can be welded on the PCB board;

[0104] The second filtering module 62 includes a thirteenth resistor MR13, a fourteenth resistor MR14, a fifth capacitor C5 and a sixth capacitor C6, and is used to filter the DC current;

[0105] The second operational amplifier 63 includes a fifth connection terminal P5, a second connection terminal P6, a third connection terminal P7, a fourth connection terminal P8 and a ground terminal. The third connection terminal P7 is connected to the thirteenth resistor MR13, the second connection terminal P6 is connected to the fourteenth resistor MR14, a fourth capacitor C4 and a fifteenth resistor MR15 connected in parallel are provided between the fifth connection terminal P5 and the second connection terminal P6, a sixteenth resistor MR16 and a third capacitor C3 connected in parallel are provided between the thirteenth resistor MR13 and the third connection terminal P7, and the fourth connection terminal L8 is an output terminal; the fifth connection terminal P5, the second connection terminal P6, the third connection terminal P7, the fourth connection terminal P8 and the fifth connection terminal P5 of the second operational amplifier 63 can be welded on a PCB board, or can be integrated inside the second magnetic sensor chip 61, and can be set according to actual needs.

[0106] The ninth resistor MR8 and the tenth resistor MR10 are connected in series to form a third resistor group, the eleventh resistor MR11 and the twelfth resistor MR12 are connected in series to form a fourth resistor group, and the third resistor group and the fourth resistor group are connected in parallel to form the second magnetic sensor chip 61; and

[0107] The resistance value of the thirteenth resistor MR13 is the same as the resistance value of the fourteenth resistor MR14 , and the resistance value of the fifteenth resistor MR15 is the same as the resistance value of the sixteenth resistor MR16 .

[0108] Furthermore, the fifth capacitor C5 and the sixth capacitor C6 are high-pass capacitors, and the high-pass frequencies are both:

[0109] f3=1 / (2*PI*C5*L 13 ),

[0110] The frequencies of the third capacitor C3 and the fourth capacitor C4 are both:

[0111] f2=1 / (2*PI*C2*L 15 );

[0112] Among them, C5 is the capacitance value of the fifth capacitor C5, MR13 is the resistance value of the thirteenth resistor, the capacitance value of the third capacitor C3 is the same as the capacitance value of the fourth capacitor C4, and the capacitance value of the fifth capacitor C5 is the same as the capacitance value of the sixth capacitor C6.

[0113] At the same time, the sensitivity of the second magnetic sensor chip 61 is 2mV / V / Gs-5mV / V / Gs, such as 2mV / V / Gs, 3mV / V / Gs, 4mV / V / Gs or 5mV / V / Gs. The gain β of the second magnetic sensor chip 61 is the ratio of the resistance value of the fifteenth resistor to the resistance value of the fourteenth resistor. Since the current signal is small, only mA-level current is useful, so a sensor chip with higher sensitivity is required, and the second magnetic sensor chip cannot be saturated due to too large a DC component. The signal sensed by the arc detection chip needs to be processed by the circuit to filter out the DC signal, and only the arc signal is amplified and processed to the back-end detection circuit.

[0114] Arc current detection chip, as the magnetic field changes, the induced voltage signal also changes. Specifically, the relationship between the induced voltage signal and the magnetic field change is shown in Figure 8 As shown. Figure 8 In the figure, the horizontal axis represents the induced magnetic field strength, and the vertical axis represents the output voltage of the arc current detection chip. It can be seen from the figure that when the magnetic field induced by the arc current detection chip reaches 200Gs, the output voltage of the arc current detection chip can reach 200mV.

[0115] Specifically, in the embodiment of the present application, the arc current detection chip operates in a DC signal range of about 100Gs, such as 80Gs-110Gs. When the arc signal is superimposed on the DC component, the arc signal varies around 100Gs.

[0116] In the embodiment of the present application, the output voltage V out2 for:

[0117] V out2 =β2*I2*Sen2*M2+Vref2;

[0118] Wherein, β2 is the amplification factor of the second magnetic sensor chip, I2 is the primary current, Sen2 is the sensitivity of the second magnetic sensor chip, M2 is the magnetic field generated by each 1A DC current, and Vref2 is the bias voltage of the second magnetic sensor chip. In this embodiment, I2 and I1 are both primary currents, that is, the current in the wire passing through the first magnetic core and the second magnetic core.

[0119] As follows, a specific embodiment is given to illustrate:

[0120] A voltage of 0.8V-1.2V, such as 1V, is provided to the arc current detection chip, and then in this application scenario, a magnetic field of ±200Gs is applied to detect the output of the arc current detection chip.

[0121] In an embodiment of the present application, the sensor capable of simultaneously detecting direct current and arc current further includes:

[0122] The fixing assembly 38 includes a bottom plate 381 and a plurality of fixing pins 382 fixed on one surface of the bottom plate, and is connected to one surface of the first part of the PCB board through the other surface of the bottom plate 381.

[0123] A specific embodiment of detecting DC current and arc current by using the sensor capable of simultaneously detecting DC current and arc current provided by the embodiment of the present application is listed below:

[0124] Set the inverter current between 5kHz and 100kHz to simulate the primary arc current. Add 10mA 10K Hz AC current to the primary on the basis of 10A DC current to detect the output of the DC current detection chip. For details, see Figure 9a As shown. Figure 9a In the figure, the horizontal axis represents the DC current value, and the vertical axis represents the output of the first magnetic sensor chip of the DC current detection chip provided in the embodiment of the present application. It can be seen from the figure that when the DC current value is 25A, the output voltage of the first magnetic sensor chip is 4.5V. It is pointed out that the output voltage includes the bias voltage of the first magnetic sensor chip. If the bias voltage of the second magnetic sensor chip is 2.5V, the actual output voltage of the first magnetic sensor chip is 2V. It is pointed out that the bias voltage can be set according to actual needs, and there is no specific restriction on the value thereof.

[0125] See also Figure 9b As shown in FIG. 1 , the relationship between the arc current detected by the second magnetic sensor chip of the arc current detection chip and the output voltage is shown in FIG. Figure 9b In the figure, the horizontal axis represents the arc current detected by the second magnetic sensor chip, and the vertical axis represents the output voltage of the second magnetic sensor chip. It can be seen from the figure that when the arc current detected by the second magnetic sensor chip is 100mA, its output voltage is 4.5V.

[0126] It is pointed out here that the embodiment of the present application selects a frequency range including the arc circuit frequency, such as a frequency of 5KHz to 100KHz. Based on the fact that within this range, the output of the sensor that can simultaneously detect the DC current and the arc current is relatively flat, and the output voltage does not change with the change of the frequency. For details, see Fig.10 shown.

[0127] The sensor provided in the embodiment of the present application that can simultaneously detect DC current and arc current can be fixed by a fixing component 38 to prevent the signal processing module and other modules from being damaged due to rotation or shaking.

[0128] 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 created by this application.

Claims

1. A sensor capable of simultaneously detecting direct current and arc current, characterized in that: include: The outer shell comprises an inner wall and an outer wall, and a gap is arranged between the inner wall and the outer wall; A magnetic core is located in the gap and has a gap of a preset size in an open loop design on a preset side wall; A PCB board, comprising a first part and a second part, wherein the second part is connected to the first part and embedded between two side walls of the gap, and the first part is located outside the magnetic core and abuts against the side surface where the gap is located; a direct current detection chip, attached to the first surface of the second portion, for detecting direct current; An arc current detection chip, attached to the second surface of the second part, for detecting the arc current; A signal processing module, connected to the DC current detection chip and the arc current detection chip, respectively, to process and output the detected DC current signal and arc current signal; wherein the second surface is opposite to the first surface; In the processing module, the circuit structure of the processing unit corresponding to the DC current detection chip includes: A first magnetic sensor chip consisting of a first resistor, a second resistor, a third resistor and a fourth resistor; A first filtering module, including a fifth resistor and a sixth resistor, for filtering an alternating current; A first operational amplifier includes a first connection terminal, a second connection terminal, a third connection terminal, a fourth connection terminal and a ground terminal, the third connection terminal is connected to a fifth resistor, the second connection terminal is connected to a sixth resistor, a second capacitor and a seventh resistor connected in parallel are provided at the first connection terminal and the second connection terminal, an eighth resistor and a first capacitor connected in parallel are provided between the fifth resistor and the third connection terminal, and the fourth connection terminal is an output terminal; Or, in the processing module, the circuit structure of the processing unit corresponding to the arc current detection chip includes: a second magnetic sensor chip consisting of a ninth resistor, a tenth resistor, an eleventh resistor and a twelfth resistor; A second filtering module, including a thirteenth resistor, a fourteenth resistor, a fifth capacitor and a sixth capacitor, for filtering a DC current; The second operational amplifier includes a first connection terminal, a second connection terminal, a third connection terminal, a fourth connection terminal and a ground terminal, the third connection terminal is connected to the thirteenth resistor, the second connection terminal is connected to the fourteenth resistor, a fourth capacitor and a fifteenth resistor connected in parallel are provided at the first connection terminal and the second connection terminal, a sixteenth resistor and a third capacitor connected in parallel are provided between the thirteenth resistor and the third connection terminal, and the fourth connection terminal is an output terminal.

2. The sensor capable of simultaneously detecting direct current and arc current according to claim 1, characterized in that: The side wall of the gap is provided with a first flange protruding outward, and a first recess matching the first flange is provided at a corresponding position of the first part of the PCB board. The first flange matches the first recess so that the first part of the PCB board is tightly fitted with the preset side wall.

3. The sensor capable of simultaneously detecting direct current and arc current according to claim 1, characterized in that: A fixing piece is arranged on one side of the inner wall close to the gap of the magnetic core. The fixing member abuts against the preset side edges of the two side walls of the gap to fix the magnetic core.

4. The sensor capable of simultaneously detecting direct current and arc current according to claim 3, 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 on both sides of the gap.

5. The sensor capable of simultaneously detecting direct current and arc current according to claim 1, characterized in that: The DC current detection chip and the arc current detection chip are both full-bridge chips.

6. The sensor capable of simultaneously detecting direct current and arc current according to claim 5, characterized in that: The first resistor and the second resistor are connected in series to form a first resistor group, the third resistor and the fourth resistor are connected in series to form a second resistor group, and the first resistor group and the second resistor group are connected in parallel to form the first magnetic sensor chip; and The capacitance value of the first capacitor is the same as the capacitance value of the second capacitor, and the resistance value of the seventh resistor is the same as the resistance value of the eighth resistor.

7. The sensor capable of simultaneously detecting direct current and arc current according to claim 6, characterized in that: The low-pass frequencies of the first capacitor and the second capacitor are both f1=1 / (2*PI*C1*L7); Wherein, C1 is the capacitance value of the first capacitor, L7 is the resistance value of the seventh resistor, and PI is the value of pi.

8. The sensor capable of simultaneously detecting direct current and arc current according to claim 1, characterized in that: The sensitivity of the first magnetic sensor chip is 0.1mV / V / Gs-0.5mV / V / Gs.

9. The sensor capable of simultaneously detecting direct current and arc current according to claim 1, characterized in that: The output voltage V of the DC current detection chip out1 for: In out1 =β1*I1*Sen1*M1+Vref1; Wherein, β1 is the amplification factor of the first magnetic sensor chip, I1 is the primary current, Sen1 is the sensitivity of the first magnetic sensor chip, M1 is the magnetic field generated by each 1A DC current, and Vref1 is the bias voltage of the first magnetic sensor chip.

10. The sensor capable of simultaneously detecting direct current and arc current according to claim 5, characterized in that: The ninth resistor and the tenth resistor are connected in series to form a third resistor group, the eleventh resistor and the twelfth resistor are connected in series to form a fourth resistor group, and the third resistor group and the fourth resistor group are connected in parallel to form the second magnetic sensor chip; and The resistance value of the thirteenth resistor is the same as the resistance value of the fourteenth resistor, and the resistance value of the fifteenth resistor is the same as the resistance value of the sixteenth resistor.

11. The sensor capable of simultaneously detecting direct current and arc current according to claim 10, characterized in that: The frequencies of the third capacitor and the fourth capacitor are both: f2=1 / (2*PI*C5*L 13 ); Wherein, C5 is the capacitance value of the fifth capacitor, L 13 is the resistance value of the thirteenth resistor.

12. The sensor capable of simultaneously detecting direct current and arc current according to claim 10, characterized in that: The sensitivity of the second magnetic sensor chip is 2mV / V / Gs-5mV / V / Gs.

13. The sensor capable of simultaneously detecting direct current and arc current according to claim 6, characterized in that: The output voltage V of the arc current detection chip out2 for: <h2 style=";text-align:left;direction:ltr">V<h2 style=";text-align:left;direction:ltr"> out2 <h2 style=";text-align:left;direction:ltr"> (β2*I2*Sen2*M2+Vref2) Among them, β2 is the amplification factor of the first magnetic sensor chip, I2 is the primary current, Sen2 is the sensitivity of the first magnetic sensor chip, M2 is the magnetic field generated by each 1A DC current, and Vref2 is the bias voltage of the second magnetic sensor chip.

14. The sensor capable of simultaneously detecting direct current and arc current according to any one of claims 1 to 13, characterized in that: Also includes: The fixing component comprises a bottom plate and fixing pins fixed on one surface of the bottom plate, and is connected with one surface of the first part of the PCB board through the other surface of the bottom plate.

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