Residual current detection device for multi-pulse surge protection device

Abstract

The utility model discloses a residual current detection device for a multi-pulse surge protection device, and the device comprises a surge absorption circuit, a residual current monitoring circuit, and a single-chip microcomputer. A Hall current sensor of the residual current monitoring circuit measures a magnetic field generated by leakage current of a grounding wire in a non-contact mode and converts the magnetic field into a voltage signal which is sequentially output to the subtraction circuit and the amplification circuit, the amplification circuit amplifies the voltage signal and then inputs the voltage signal into the single-chip microcomputer, and the single-chip microcomputer carries out data analysis on the magnitude of residual current. The residual current can be detected without connecting the live wire and the ground wire of the surge protection device for power supply and sampling, thereby solving the problems that the detection circuit may fail or even the live wire of the line is directly conducted with the ground wire when the existing residual current detection equipment for the multi-pulse surge protection device is directly connected with the live wire and the ground wire of the surge protection device for power supply and sampling; and potential safety hazards are caused.

Description

TECHNICAL FIELD

[0001] The utility model relates to multi -pulse electric surge protector technical field especially, it relates to a kind of multi -pulse electric surge protector residual flow detection device. BACKGROUND

[0002] Multi-pulse surge protector, referred to as MSPD. The residual current (also referred to as residual current) of the multi-pulse surge protector refers to the current flowing through the PE terminal when the reference voltage (voltage effective value for MSPD testing) is applied when the multi-pulse surge protector is connected according to the manufacturer's instructions. The existing built-in residual current detection device directly connects the live wire and the ground wire of the surge protector for power supply and sampling. Once the lightning current is too large or exceeds the withstand capability of the zinc oxide resistor, it may cause detection circuit failure or even direct conduction of the line live wire to the ground wire, causing safety hazards. SUMMARY

[0003] The utility model provides a kind of multi-pulse electric surge protector residual flow detection device, for solving the technical problem that the residual current detection device of existing multi-pulse electric surge protector is directly connected for power supply and sampling by the live wire and the ground wire of electric surge protector, may cause detection circuit failure or even direct conduction of the line live wire to the ground wire, cause safety hazards.

[0004] Therefore, the utility model provides a kind of multi-pulse electric surge protector residual flow detection device, comprising: surge absorption circuit, residual flow monitoring circuit and single-chip microcomputer;

[0005] The lightning current is introduced into the ground wire by the surge absorption circuit.

[0006] The residual flow monitoring circuit includes a Hall current sensor, a subtraction circuit, and an amplification circuit. The magnetic core of the Hall current sensor is sleeved on the ground wire of the multi-pulse surge protector. The voltage output end of the Hall current sensor is connected with the same-phase input end of the subtraction circuit. The output end of the subtraction circuit is connected with the same-phase input end of the amplification circuit. The output end of the amplification circuit is connected with the input end of the single-chip microcomputer.

[0007] Optionally, the subtraction circuit includes a first operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, and a first capacitor.

[0008] One end of the first resistor is connected to the voltage output terminal of the Hall current sensor, and the other end of the first resistor is connected to the non-inverting input terminal of the first operational amplifier. One end of the second resistor is connected to the non-inverting input terminal of the first operational amplifier, and the other end of the second resistor is grounded. One end of the third resistor is connected to the reference voltage source, and the other end of the third resistor is connected to the inverting input terminal of the first operational amplifier. One end of the fourth resistor is connected to the inverting input terminal of the first operational amplifier, and the other end of the fourth resistor is connected to the output terminal of the first operational amplifier. One end of the first capacitor is connected to the inverting input terminal of the first operational amplifier, and the other end of the first capacitor is connected to the output terminal of the first operational amplifier.

[0009] Optionally, the amplifier circuit includes a second operational amplifier, a fifth resistor, a sixth resistor, a seventh resistor, and a second capacitor;

[0010] One end of the fifth resistor is connected to the output of the first operational amplifier, and the other end of the fifth resistor is connected to the non-inverting input of the second operational amplifier. One end of the sixth resistor is grounded, and the other end of the sixth resistor is connected to the inverting input of the second operational amplifier. One end of the seventh resistor is connected to the inverting input of the second operational amplifier, and the other end of the seventh resistor is connected to the output of the second operational amplifier. One end of the second capacitor is connected to the inverting input of the second operational amplifier, and the other end of the second capacitor is connected to the output of the second operational amplifier.

[0011] Optionally, it also includes a lightning current monitoring circuit;

[0012] The lightning current monitoring circuit includes a Rogowski coil and a signal integration circuit. The Rogowski coil is connected to the grounding wire of the multi-pulse surge protector, and the induced current output terminal of the Rogowski coil is connected to the input terminal of the signal integration circuit.

[0013] The signal integration circuit includes a first integration circuit, a second integration circuit, and a signal amplification circuit;

[0014] The first integrating circuit includes a third operational amplifier, an eighth resistor, a ninth resistor, and a third capacitor. One end of the eighth resistor is connected to the positive terminal of the induced current output terminal of the Rogowski coil, and the other end of the eighth resistor is connected to the inverting input terminal of the third operational amplifier. The non-inverting input terminal of the third operational amplifier is grounded and the negative terminal of the induced current output terminal of the Rogowski coil is connected to the ground. One end of the ninth resistor is connected to the inverting input terminal of the third operational amplifier, and the other end of the ninth resistor is connected to the output terminal of the third operational amplifier. One end of the third capacitor is connected to the inverting input terminal of the third operational amplifier, and the other end of the third capacitor is connected to the output terminal of the third operational amplifier.

[0015] The second integration circuit comprises a fourth operational amplifier, a tenth resistor, an eleventh resistor, a twelfth resistor and a fourth capacitor, one end of the tenth resistor is connected with the output end of the third operational amplifier, the other end of the tenth resistor is connected with the non-inverting input end of the fourth operational amplifier, one end of the eleventh resistor is grounded, the other end of the eleventh resistor is connected with the inverting input end of the fourth operational amplifier, one end of the twelfth resistor is connected with the inverting input end of the fourth operational amplifier, the other end of the twelfth resistor is connected with the output end of the fourth operational amplifier, one end of the fourth capacitor is connected with the inverting input end of the fourth operational amplifier, the other end of the fourth capacitor is connected with the output end of the fourth operational amplifier;

[0016] The signal amplification circuit comprises a fifth operational amplifier, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor and a fifth capacitor, one end of the thirteenth resistor is connected with the output end of the fourth operational amplifier, the other end of the thirteenth resistor is connected with the non-inverting input end of the fifth operational amplifier, one end of the fourteenth resistor is connected with the non-inverting input end of the fifth operational amplifier, the other end of the fourteenth resistor is connected with a reference voltage source, one end of the fifteenth resistor is grounded, the other end of the fifteenth resistor is connected with the inverting input end of the fifth operational amplifier, one end of the sixteenth resistor is connected with the inverting input end of the fifth operational amplifier, the other end of the sixteenth resistor is connected with the output end of the fifth operational amplifier, one end of the fifth capacitor is connected with the inverting input end of the fifth operational amplifier, the other end of the fifth capacitor is connected with the inverting input end of the fifth operational amplifier, and the output end of the fifth operational amplifier is connected with the input end of the single-chip microcomputer.

[0017] Optionally, the device further comprises a data storage module;

[0018] The input end of the data storage module is connected with the output end of the lightning current monitoring circuit.

[0019] The data storage module is used for storing lightning current waveform data collected at a rate of 1Mhz when the transient current flowing through the grounding wire of the multi-pulse surge protector exceeds 1kA, and the lightning current waveform data comprises lightning current waveform, pulse time, pulse number, pulse time interval, pulse amplitude and pulse steepness.

[0020] Optionally, the device further comprises a power module;

[0021] The power module comprises a Buck step-down circuit, and the step-down circuit is used for providing +5VDC power supply for the multi-pulse surge protector residual current detection device.

[0022] Optionally, the Buck step-down circuit comprises a step-down chip, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a diode, a voltage stabilizing tube and an inductor.

[0023] One end of the sixth capacitor is connected with the power supply VCC, and the other end of the sixth capacitor is grounded.

[0024] The VIN pin of the voltage reduction chip is connected with the power supply VCC, the GND pin is grounded, the EN pin is connected with one end of the seventeenth resistor, one end of the seventeenth resistor is connected with the VIN pin, the VIA pin is suspended, the IS pin is connected with one end of the eighteenth resistor, the other end of the eighteenth resistor is connected with the VS pin and one end of the inductor respectively, the VB pin is connected with one end of the eighth capacitor, the other end of the eighth capacitor is connected with the other end of the inductor, the other end of the inductor is connected with one end of the nineteenth resistor, the other end of the nineteenth resistor is grounded, one end of the ninth capacitor is connected with the other end of the inductor, the other end of the ninth capacitor is grounded, the common end of the inductor, the nineteenth resistor and the ninth capacitor is connected with the +5V power supply, the FB pin of the voltage reduction chip is connected with one end of the twentieth resistor and the twenty-first resistor respectively, the other end of the twentieth resistor is grounded, the other end of the twenty-first resistor is connected with the anode of the diode, the cathode of the diode is connected with the cathode of the voltage stabilizing tube, the anode of the voltage stabilizing tube is connected with the other end of the eighth capacitor, one end of the tenth capacitor is connected with one end of the twenty-first resistor, and the other end of the tenth capacitor is connected with the other end of the twenty-first resistor.

[0025] Optionally, the power module further comprises an LDO voltage reduction circuit, and the LDO voltage reduction circuit is used for providing a +3.3VDC power supply for the multi-pulse surge protector residual current detection device.

[0026] Optionally, the outer surfaces of the Hall current sensor and the lightning current monitoring circuit are covered with aluminum foil shielding layers, and the aluminum foil shielding layers are grounded through screws and guide rails.

[0027] Optionally, the outer surface of the aluminum foil shielding layer is covered with an insulation and heat insulation electronic adhesive layer.

[0028] It can be seen from the above technical solutions that the multi-pulse surge protector residual current detection device has the following advantages:

[0029] The multi-pulse surge protector residual current detection device provided by the utility model, including surge absorption circuit, residual current monitoring circuit and single-chip microcomputer, through the lightning current introduction ground wire of surge absorption circuit, through the Hall current sensor of residual current monitoring circuit non-contact measurement ground wire leakage current generated magnetic field and conversion voltage signal output to subtraction circuit and amplifier circuit in turn, the voltage signal is amplified and input to the single-chip microcomputer, and the size of residual current is analyzed through the single-chip microcomputer, and residual current can be detected without connecting the live wire and ground wire of surge protector for power supply and sampling, the technical problem that the live wire and ground wire of the existing multi-pulse surge protector residual current detection equipment are directly connected for power supply and sampling, which may cause detection circuit failure even line live wire direct conduction with ground wire, and cause safety hazards is solved.

[0030] Meanwhile, the multi-pulse surge protector residual current detection device provided by the utility model, the outer surface of the Hall current sensor and the lightning current monitoring circuit is covered with an aluminum foil shielding layer, the aluminum foil shielding layer is connected to the guide rail ground through screws, and the outer part of the aluminum foil shielding layer is covered with a heat insulation layer made of insulating heat insulation electronic glue, which can protect the multi-pulse surge protector residual current detection device from damage caused by lightning electromagnetic pulses and heat energy and the influence of data acquisition accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiment or the prior art description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and those skilled in the art can also obtain other related drawings according to these drawings without creating labor.

[0032] Figure 1 It is a structural schematic view of the multi-pulse surge protector residual current detection device provided in the embodiments of the utility model.

[0033] Figure 2 It is a circuit principle diagram of the surge absorption circuit provided in the embodiments of the utility model.

[0034] Figure 3 It is a circuit principle diagram of the switch circuit module provided in the embodiments of the utility model.

[0035] Figure 4 It is a subtraction circuit principle diagram in the residual current monitoring circuit provided in the embodiments of the utility model.

[0036] Figure 5 It is an amplifier circuit principle diagram in the residual current monitoring circuit provided in the embodiments of the utility model.

[0037] Figure 6The circuit principle diagram of the display screen is provided in the embodiment of the utility model.

[0038] Figure 7 The signal integration circuit principle diagram is provided in the embodiment of the utility model.

[0039] Figure 8 The data storage module circuit principle diagram is provided in the embodiment of the utility model.

[0040] Figure 9 The Buck voltage reduction circuit principle diagram is provided in the embodiment of the utility model.

[0041] Figure 10 The LDO voltage reduction circuit principle diagram is provided in the embodiment of the utility model.

[0042] Figure 11 The internal structure schematic diagram of the multi-pulse surge protector is provided in the embodiment of the utility model. DETAILED DESCRIPTION

[0043] In order to make the personnel in the art better understand the utility model scheme, the technical scheme in the embodiment of the utility model will be described clearly and completely below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiments are only a part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor fall within the scope of protection of the utility model.

[0044] For the convenience of understanding, please refer to Figure 1 The embodiment of the multi-pulse surge protector residual flow detection device is provided in the utility model, which comprises a surge absorption circuit, a residual flow monitoring circuit and a single-chip microcomputer. The surge absorption circuit is used for introducing lightning current into the ground wire. The residual flow monitoring circuit comprises a Hall current sensor, a subtraction circuit and an amplification circuit. The magnetic core of the Hall current sensor is sleeved on the ground wire of the multi-pulse surge protector. The voltage output end of the Hall current sensor is connected with the non-inverting input end of the subtraction circuit. The output end of the subtraction circuit is connected with the non-inverting input end of the amplification circuit. The output end of the amplification circuit is connected with the input end of the single-chip microcomputer.

[0045] It should be noted that the surge absorption circuit is used for introducing lightning current into the ground wire. The structure of the surge absorption circuit is as follows Figure 2As shown, including the first pulse dedicated fuse F1, the second pulse dedicated fuse F2, the third pulse dedicated fuse F3, the first thermal protection type varistor R31, the second thermal protection type varistor R32 and the third thermal protection type varistor R33, the first pulse dedicated fuse F1 and the first thermal protection type varistor R31 are connected in series to form the first surge absorption branch, the second pulse dedicated fuse F2 and the second thermal protection type varistor R32 are connected in series to form the second surge absorption branch, and the third pulse dedicated fuse F3 and the third thermal protection type varistor R33 are connected in series to form the third surge absorption branch. The three surge absorption branches are connected in parallel, the common end of the first thermal protection type varistor R31, the second thermal protection type varistor R32 and the third thermal protection type varistor R33 is connected to ground, and the common end of the first pulse dedicated fuse F1, the second pulse dedicated fuse F2 and the third pulse dedicated fuse F3 is connected to the AC power supply VAC. The magnetic core of the Hall current sensor is sleeved on the ground wire of the multi-pulse surge protector, and the flow of lightning current through the ground wire of the multi-pulse surge protector will cause the magnetic core of the Hall current sensor to change the magnetic field. When it is necessary to detect the leakage current of the multi-pulse surge protector, the single-chip microcomputer controls the Hall element of the Hall current sensor to work, and the Hall element of the Hall current sensor converts the detected magnetic field into a voltage signal, which is respectively passed through a subtraction circuit and an amplification circuit, and finally output to the ADC chip of the single-chip microcomputer for processing. A switch circuit module can be provided for triggering the single-chip microcomputer to detect the leakage current of the multi-pulse surge protector, such as Figure 3 As shown, one end of the switch SW1 is connected to the +3.3V power supply and one end of the filter capacitor CL, the other end of the filter capacitor CL is connected to ground, the other end of the switch SW1 is connected to the single-chip microcomputer through the IO18 pin of the single-chip microcomputer, and the other end of the switch SW1 is connected to one end of the grounding resistor RL, the other end of the grounding resistor RL is connected to ground. When the switch SW1 is pressed, the single-chip microcomputer receives a trigger signal, controls the Hall element of the Hall current sensor to work, and collects the leakage current of the multi-pulse surge protector. As Figure 4As shown, the subtraction circuit includes a first operational amplifier U1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and a first capacitor C1. R1=R2=R3=R4=100K, C1=100pF. One end of the first resistor R1 is connected with the voltage output end BIAS of the Hall current sensor, the other end of the first resistor R1 is connected with the non-inverting input end of the first operational amplifier U1, one end of the second resistor R2 is connected with the non-inverting input end of the first operational amplifier U1, the other end of the second resistor R2 is grounded, one end of the third resistor R3 is connected with the reference voltage source VREF, the other end of the third resistor R3 is connected with the inverting input end of the first operational amplifier U1, one end of the fourth resistor R4 is connected with the inverting input end of the first operational amplifier U1, the other end of the fourth resistor R4 is connected with the output end HGAIN of the first operational amplifier U1, one end of the first capacitor C1 is connected with the inverting input end of the first operational amplifier U1, the other end of the first capacitor C1 is connected with the output end HGAIN of the first operational amplifier U1. The subtraction circuit biases the voltage signal downward by 2.5V and inputs into the amplification circuit. As shown, Figure 5 As shown, the amplification circuit includes a second operational amplifier U2, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and a second capacitor C2. One end of the fifth resistor R5 is connected with the output end HGAIN of the first operational amplifier U1, the other end of the fifth resistor R5 is connected with the non-inverting input end of the second operational amplifier U2, one end of the sixth resistor R6 is grounded, the other end of the sixth resistor R6 is connected with the inverting input end of the second operational amplifier U2, one end of the seventh resistor R7 is connected with the inverting input end of the second operational amplifier U2, the other end of the seventh resistor R7 is connected with the output end of the second operational amplifier U2, one end of the second capacitor C2 is connected with the inverting input end of the second operational amplifier U2, the other end of the second capacitor C2 is connected with the output end of the second operational amplifier U2. R5=R6=10K, R7=100K, C2=100pF. The amplification circuit amplifies the voltage signal of the output end HGAIN of the first operational amplifier U1 by 100 times and inputs into the ADC chip in the single-chip microcomputer from the IO19 pin of the single-chip microcomputer for processing. When the single-chip microcomputer monitors that the leakage current flowing through the grounding wire of the multi-pulse surge protector exceeds 30mA, corresponding information is displayed in the display screen for prompting, and it is determined that the multi-pulse surge protector is unqualified. The single-chip microcomputer can control the display screen to display data through the SPI protocol. The display screen uses HS91L02W2C01 chip, and its circuit principle is as shown in Figure 6 As shown.

[0046] The multi-pulse surge protector residual current detection device provided by the utility model, through the lightning current absorption circuit, introduces the lightning current into the grounding wire, through the Hall current sensor of the residual current monitoring circuit, non-contact measures the magnetic field generated by the grounding wire leakage current and converts into voltage signals output to the subtraction circuit and the amplification circuit in turn, the amplification circuit inputs the voltage signals amplified into the single-chip microcomputer, through the single-chip microcomputer, analyzes the size of residual current, without connecting the live wire and the grounding wire of the surge protector for power supply and sampling, can detect the residual current, solves the technical problem that the existing multi-pulse surge protector residual current detection equipment directly connects the live wire and the grounding wire of the surge protector for power supply and sampling, may cause detection circuit failure even the live wire directly conducts with the grounding wire, causes the safety hidden trouble.

[0047] In one embodiment, the multi-pulse surge protector residual current detection device provided in the utility model further comprises a lightning current monitoring circuit. The lightning current monitoring circuit comprises a Rogowski coil and a signal integration circuit, the Rogowski coil is sleeved on the grounding wire of the multi-pulse surge protector, and the induced current output end of the Rogowski coil is connected with the input end of the signal integration circuit. The Rogowski coil is used as a current sensor, its high transient response can sensitively monitor the natural physical parameters of lightning current, and the current signal induced by the Rogowski coil is transmitted into the signal integration circuit for processing. As shown in Figure 7 , the signal integration circuit comprises a first integration circuit, a second integration circuit and a signal amplification circuit. The first integration circuit comprises a third operational amplifier U3, an eighth resistor R8, a ninth resistor R9 and a third capacitor C3. R8=1K, R9=200K, and C3=100nF. One end of the eighth resistor R8 is connected with the positive end of the induced current output end of the Rogowski coil (corresponding to the No. 2 pin of the pin H2 in Figure 7 ), the other end of the eighth resistor R8 is connected with the inverting input end of the third operational amplifier U3, and the noninverting input end of the third operational amplifier U3 is connected with the grounding wire and the negative end of the induced current output end of the Rogowski coil (corresponding to the No. 1 pin of the pin H2 in Figure 7The first pin of the pin H2 in the middle of the first resistor R1, the other end of the first resistor R1 is connected with the non-inverting input terminal of the first operational amplifier U1, the other end of the second resistor R2 is connected with the output terminal of the first operational amplifier U1, one end of the third resistor R3 is connected with the inverting input terminal of the second operational amplifier U2, the other end of the third resistor R3 is connected with the output terminal of the second operational amplifier U2, one end of the fourth resistor R4 is connected with the inverting input terminal of the third operational amplifier U3, the other end of the fourth resistor R4 is connected with the output terminal of the third operational amplifier U3, one end of the fifth resistor R5 is connected with the inverting input terminal of the fourth operational amplifier U4, the other end of the fifth resistor R5 is connected with the output terminal of the fourth operational amplifier U4, one end of the sixth resistor R6 is connected with the inverting input terminal of the fifth operational amplifier U5, the other end of the sixth resistor R6 is connected with the output terminal of the fifth operational amplifier U5, one end of the seventh resistor R7 is connected with the inverting input terminal of the sixth operational amplifier U6, the other end of the seventh resistor R7 is connected with the output terminal of the sixth operational amplifier U6, one end of the eighth resistor R8 is connected with the inverting input terminal of the seventh operational amplifier U7, the other end of the eighth resistor R8 is connected with the output terminal of the seventh operational amplifier U7, one end of the ninth resistor R9 is connected with the inverting input terminal of the third operational amplifier U3, the other end of the ninth resistor R9 is connected with the output terminal of the third operational amplifier U3, one end of the third capacitor C3 is connected with the inverting input terminal of the third operational amplifier U3, the other end of the third capacitor C3 is connected with the output terminal of the third operational amplifier U3. The transient current induced in the Rogowski coil is input into the first integration circuit to convert the current signal into a voltage signal, and then input into the second integration circuit. The second integration circuit includes the fourth operational amplifier U4, the tenth resistor R10, the eleventh resistor R11, the twelfth resistor R12 and the fourth capacitor C4. R10=10.2K, R12=11K, R13=150K, C4=100pF. One end of the tenth resistor R10 is connected with the output terminal of the third operational amplifier U3, the other end of the tenth resistor R10 is connected with the non-inverting input terminal of the fourth operational amplifier U4, one end of the eleventh resistor R11 is connected with the ground, the other end of the eleventh resistor R11 is connected with the inverting input terminal of the fourth operational amplifier U4, one end of the twelfth resistor R12 is connected with the inverting input terminal of the fourth operational amplifier U4, the other end of the twelfth resistor R12 is connected with the output terminal of the fourth operational amplifier R4, one end of the fourth capacitor C4 is connected with the inverting input terminal of the fourth operational amplifier U4, the other end of the fourth capacitor C4 is connected with the output terminal of the fourth operational amplifier U4. The signal amplification circuit includes the fifth operational amplifier U5, the thirteenth resistor R13, the fourteenth resistor R14, the fifteenth resistor R15, the sixteenth resistor R16 and the fifth capacitor C5. R14=R15=R16=R17=100K, C8=100pF. One end of the thirteenth resistor R13 is connected with the output terminal of the fourth operational amplifier U4, the other end of the thirteenth resistor R13 is connected with the non-inverting input terminal of the fifth operational amplifier U5, one end of the fourteenth resistor R14 is connected with the non-inverting input terminal of the fifth operational amplifier U5, the other end of the fourteenth resistor R14 is connected with the reference voltage source VREF, one end of the fifteenth resistor R15 is connected with the ground, the other end of the fifteenth resistor R15 is connected with the inverting input terminal of the fifth operational amplifier U5, one end of the sixteenth resistor R16 is connected with the inverting input terminal of the fifth operational amplifier R5, the other end of the sixteenth resistor R16 is connected with the output terminal of the fifth operational amplifier U5, one end of the fifth capacitor C5 is connected with the inverting input terminal of the fifth operational amplifier U5, the other end of the fifth capacitor C5 is connected with the inverting input terminal of the fifth operational amplifier U5, the output terminal of the fifth operational amplifier U5 is connected with the input terminal of the single-chip microcomputer. The signal amplification circuit controls the voltage at 0~3.3V and inputs into the ADC chip of the single-chip microcomputer through the IO6 pin of the single-chip microcomputer for processing.

[0048] In one embodiment, the multi-pulse surge protector residual current detection device provided in the utility model further comprises a data storage module. The input end of the data storage module is connected with the output end of the lightning current monitoring circuit. The data storage module is used for storing the lightning current waveform data collected at a rate of 1Mhz when the transient current flowing through the grounding wire of the multi-pulse surge protector exceeds 1kA, and the lightning current waveform data comprises lightning current waveform, pulse time, pulse number, pulse time interval, pulse amplitude and pulse steepness. The data storage module adopts a W25Q16JVSSIQ chip, and the circuit principle is as shown in Figure 8 .

[0049] In one embodiment, the multi-pulse surge protector residual current detection device provided in the utility model further comprises a power module, and the power module comprises a Buck step-down circuit. The step-down circuit is used for providing +5VDC power supply for the internal circuit of the multi-pulse surge protector residual current detection device. As shown in Figure 9 , the Buck step-down circuit comprises a step-down chip U6, a sixth capacitor C3, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10, a seventeenth resistor R17, an eighteenth resistor R18, a nineteenth resistor R19, a twentieth resistor R20, a twenty-first resistor R21, a diode D1, a voltage stabilizing tube D2 and an inductor L. One end of the sixth capacitor C6 is connected with a power supply VCC, and the other end of the sixth capacitor C6 is grounded. One end of the seventh capacitor C7 is connected with the power supply VCC, and the other end of the seventh capacitor C7 is grounded. The VIN pin of the step-down chip U6 is connected with the power supply VCC, the GND pin is grounded, the EN pin is connected with one end of the seventeenth resistor R17, one end of the seventeenth resistor R17 is connected with the VIN pin, the VIA pin is suspended, the IS pin is connected with one end of the eighteenth resistor R18, the other end of the eighteenth resistor R18 is respectively connected with the VS pin and one end of the inductor L, the VB pin is connected with one end of the eighth capacitor C8, the other end of the eighth capacitor C8 is connected with the other end of the inductor L, the other end of the inductor L is connected with one end of the nineteenth resistor R19, the other end of the nineteenth resistor R19 is grounded, one end of the ninth capacitor C9 is connected with the other end of the inductor L, the other end of the ninth capacitor C9 is grounded, the common end of the inductor L, the nineteenth resistor R19 and the ninth capacitor C9 is commonly connected with a +5V power supply, the FB pin of the step-down chip U6 is respectively connected with one end of the twentieth resistor R20 and one end of the twenty-first resistor R21, the other end of the twentieth resistor R20 is grounded, the other end of the twenty-first resistor R21 is connected with the anode of the diode D1, the cathode of the diode D1 is connected with the cathode of the voltage stabilizing tube D2, the anode of the voltage stabilizing tube D2 is connected with the other end of the eighth capacitor C8, one end of the tenth capacitor C10 is connected with one end of the twenty-first resistor R21, and the other end of the tenth capacitor C10 is connected with the other end of the twenty-first resistor R21. The step-down chip U6 adopts an EG1192L chip.

[0050] In one embodiment, the power module of the multi-pulse surge protector residual current detection device provided in the utility model further comprises an LDO voltage reduction circuit, which is used to provide +3.3VDC power supply for the multi-pulse surge protector residual current detection device. Figure 10 As shown in the principle of the LDO voltage reduction circuit, the LDO voltage reduction circuit comprises an LDO voltage reduction chip U7, a twenty-second resistor R22, a twenty-third resistor R23, a first electrolytic capacitor C11 and a second electrolytic capacitor C12. The LDO voltage reduction chip U7 adopts an AMS1117-3.3 chip. An ADJ pin of the LDO voltage reduction chip U7 is connected with one end of the twenty-second resistor R22, the other end of the twenty-second resistor R22 is grounded, a VOUT pin of the LDO voltage reduction chip U7 is connected with one end of the twenty-third resistor R23, the other end of the twenty-third resistor R23 is connected with one end of the twenty-second resistor R22, one end of the twenty-third resistor R23 is connected with a +3.3V power supply, a positive electrode of the first electrolytic capacitor C11 is connected with the VOUT pin of the LDO voltage reduction chip U7, a negative electrode of the first electrolytic capacitor C11 is grounded, a positive electrode of the second electrolytic capacitor C12 is connected with a VIN pin of the LDO voltage reduction chip U7, and a negative electrode of the second electrolytic capacitor C12 is grounded.

[0051] It should be noted that the multi-pulse surge protector residual current detection device provided in the utility model can be integrally arranged with the multi-pulse surge protector, and the multi-pulse surge protector residual current detection device is built-in the multi-pulse surge protector, directly collects the lightning pulse current parameters of the ground wire of the surge protector, and can solve the technical problem that the existing lightning current monitoring device needs to be additionally selected to be installed on the ground wire to collect lightning current. At the same time, the existing residual current detection is a high-voltage laboratory or uses a special instrument when leaving the factory, the multi-pulse surge protector residual current detection device can be integrally arranged with the multi-pulse surge protector, the residual current on the working line can be measured through the Hall sensor, and the residual current can be detected multiple times to judge the qualification of the surge protector when a large lightning current is experienced or in special circumstances.

[0052] In one embodiment, as shown in Figure 11 The outer surfaces of the Hall current sensor and the lightning current monitoring circuit are covered with an aluminum foil shielding layer, and the aluminum foil shielding layer is connected to the rail ground through a screw. The outer surface of the aluminum foil shielding layer is covered with a heat insulation layer made of insulating heat insulation electronic glue. The Rogowski coil and the Hall current sensor are sleeved on the ground wire of the MSPD, the Hall current sensor and the lightning current monitoring circuit are both covered with an aluminum foil shielding layer, the aluminum foil shielding layer is connected to the rail ground through an external screw, and then the outer surface of the aluminum foil shielding layer is covered with a heat insulation layer made of insulating heat insulation electronic glue, so as to avoid the influence of high heat generated by lightning current on the multi-pulse surge protector residual current detection device.

[0053] The terms "first", "second", and the like in the description of the utility model are used to distinguish similar objects, and do not have to be used to describe a particular order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the utility model described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0054] The above-described embodiments are merely used to illustrate the technical solutions of the utility model, rather than limit them; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the utility model.

Claims

1. A multi-pulse surge protector residual current detection device, characterized by, include: Surge absorption circuit, residual current monitoring circuit and microcontroller; Surge absorption circuits are used to divert lightning current into the grounding wire; The residual current monitoring circuit includes a Hall current sensor, a subtraction circuit, and an amplification circuit. The magnetic core of the Hall current sensor is fitted onto the grounding wire of the multi-pulse surge protector. The voltage output terminal of the Hall current sensor is connected to the non-inverting input terminal of the subtraction circuit. The output terminal of the subtraction circuit is connected to the non-inverting input terminal of the amplification circuit. The output terminal of the amplification circuit is connected to the input terminal of the microcontroller.

2. The multi-pulse surge protector residual current detection device according to claim 1, characterized by, The subtraction circuit includes a first operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, and a first capacitor; One end of the first resistor is connected to the voltage output terminal of the Hall current sensor, and the other end of the first resistor is connected to the non-inverting input terminal of the first operational amplifier. One end of the second resistor is connected to the non-inverting input terminal of the first operational amplifier, and the other end of the second resistor is grounded. One end of the third resistor is connected to the reference voltage source, and the other end of the third resistor is connected to the inverting input terminal of the first operational amplifier. One end of the fourth resistor is connected to the inverting input terminal of the first operational amplifier, and the other end of the fourth resistor is connected to the output terminal of the first operational amplifier. One end of the first capacitor is connected to the inverting input terminal of the first operational amplifier, and the other end of the first capacitor is connected to the output terminal of the first operational amplifier.

3. The multi-pulse surge protector residual current detection device according to claim 2, characterized in that, The amplifier circuit includes a second operational amplifier, a fifth resistor, a sixth resistor, a seventh resistor, and a second capacitor; One end of the fifth resistor is connected to the output of the first operational amplifier, and the other end of the fifth resistor is connected to the non-inverting input of the second operational amplifier. One end of the sixth resistor is grounded, and the other end of the sixth resistor is connected to the inverting input of the second operational amplifier. One end of the seventh resistor is connected to the inverting input of the second operational amplifier, and the other end of the seventh resistor is connected to the output of the second operational amplifier. One end of the second capacitor is connected to the inverting input of the second operational amplifier, and the other end of the second capacitor is connected to the output of the second operational amplifier.

4. The multi-pulse surge protector residual current detection device according to claim 1, characterized by, It also includes a lightning current monitoring circuit; The lightning current monitoring circuit includes a Rogowski coil and a signal integration circuit. The Rogowski coil is connected to the grounding wire of the multi-pulse surge protector, and the induced current output terminal of the Rogowski coil is connected to the input terminal of the signal integration circuit. The signal integration circuit includes a first integration circuit, a second integration circuit, and a signal amplification circuit; The first integrating circuit includes a third operational amplifier, an eighth resistor, a ninth resistor, and a third capacitor. One end of the eighth resistor is connected to the positive terminal of the induced current output terminal of the Rogowski coil, and the other end of the eighth resistor is connected to the inverting input terminal of the third operational amplifier. The non-inverting input terminal of the third operational amplifier is grounded and the negative terminal of the induced current output terminal of the Rogowski coil is connected to the ground. One end of the ninth resistor is connected to the inverting input terminal of the third operational amplifier, and the other end of the ninth resistor is connected to the output terminal of the third operational amplifier. One end of the third capacitor is connected to the inverting input terminal of the third operational amplifier, and the other end of the third capacitor is connected to the output terminal of the third operational amplifier. The second integration circuit comprises a fourth operational amplifier, a tenth resistor, an eleventh resistor, a twelfth resistor and a fourth capacitor, one end of the tenth resistor is connected with the output end of the third operational amplifier, the other end of the tenth resistor is connected with the non-inverting input end of the fourth operational amplifier, one end of the eleventh resistor is grounded, the other end of the eleventh resistor is connected with the inverting input end of the fourth operational amplifier, one end of the twelfth resistor is connected with the inverting input end of the fourth operational amplifier, the other end of the twelfth resistor is connected with the output end of the fourth operational amplifier, one end of the fourth capacitor is connected with the inverting input end of the fourth operational amplifier, the other end of the fourth capacitor is connected with the output end of the fourth operational amplifier; The signal amplification circuit comprises a fifth operational amplifier, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor and a fifth capacitor, one end of the thirteenth resistor is connected with the output end of the fourth operational amplifier, the other end of the thirteenth resistor is connected with the non-inverting input end of the fifth operational amplifier, one end of the fourteenth resistor is connected with the non-inverting input end of the fifth operational amplifier, the other end of the fourteenth resistor is connected with a reference voltage source, one end of the fifteenth resistor is grounded, the other end of the fifteenth resistor is connected with the inverting input end of the fifth operational amplifier, one end of the sixteenth resistor is connected with the inverting input end of the fifth operational amplifier, the other end of the sixteenth resistor is connected with the output end of the fifth operational amplifier, one end of the fifth capacitor is connected with the inverting input end of the fifth operational amplifier, the other end of the fifth capacitor is connected with the inverting input end of the fifth operational amplifier, and the output end of the fifth operational amplifier is connected with the input end of the single-chip microcomputer.

5. The multi-pulse surge protector residual current detection device according to claim 4, characterized in that, The data storage module is further included; The input end of the data storage module is connected with the output end of the lightning current monitoring circuit. The data storage module is used for storing lightning current waveform data collected at a rate of 1Mhz when the transient current flowing through the grounding wire of the multi-pulse surge protector exceeds 1kA, and the lightning current waveform data comprises lightning current waveform, pulse time, pulse number, pulse time interval, pulse amplitude and pulse steepness.

6. The multi-pulse surge protector residual current detection device according to claim 1, characterized by The power module is further included; The power module comprises a Buck step-down circuit, and the step-down circuit is used for providing +5VDC power supply for the residual current detection device of the multi-pulse surge protector.

7. The multi-pulse surge protector residual current detection device according to claim 6, characterized in that, The Buck step-down circuit comprises a step-down chip, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a diode, a voltage stabilizing tube and an inductor; One end of the sixth capacitor is connected with a power supply VCC, and the other end of the sixth capacitor is grounded. One end of the seventh capacitor is connected with the power supply VCC, and the other end of the seventh capacitor is grounded. The VIN pin of the voltage reduction chip is connected with the power supply VCC, the GND pin is grounded, the EN pin is connected with one end of the seventeenth resistor, one end of the seventeenth resistor is connected with the VIN pin, the VIA pin is suspended, the IS pin is connected with one end of the eighteenth resistor, the other end of the eighteenth resistor is connected with the VS pin and one end of the inductor respectively, the VB pin is connected with one end of the eighth capacitor, the other end of the eighth capacitor is connected with the other end of the inductor, the other end of the inductor is connected with one end of the nineteenth resistor, the other end of the nineteenth resistor is grounded, one end of the ninth capacitor is connected with the other end of the inductor, the other end of the ninth capacitor is grounded, the common end of the inductor, the nineteenth resistor and the ninth capacitor is connected with the +5V power supply, the FB pin of the voltage reduction chip is connected with one end of the twentieth resistor and the twenty-first resistor respectively, the other end of the twentieth resistor is grounded, the other end of the twenty-first resistor is connected with the anode of the diode, the cathode of the diode is connected with the cathode of the stabilizing tube, the anode of the stabilizing tube is connected with the other end of the eighth capacitor, one end of the tenth capacitor is connected with one end of the twenty-first resistor, the other end of the tenth capacitor is connected with the other end of the twenty-first resistor.

8. The multi-pulse surge protector residual current detection device according to claim 6, characterized by, The power module further comprises an LDO voltage reduction circuit, which is configured to provide a +3.3VDC power supply for the multi-pulse surge protector residual current detection device.

9. The multi-pulse surge protector residual current detection device according to claim 4, characterized by, The outer surfaces of the Hall current sensor and the lightning current monitoring circuit are covered with aluminum foil shielding layers, which are grounded through the guide rail by screws.

10. The multi-pulse surge protector residual current detection device according to claim 9, characterized in that, The outer surface of the aluminum foil shielding layer is covered with an insulating and heat-insulating electronic adhesive layer. The outer surface of the aluminum foil shielding layer is covered with an insulating and heat-insulating electronic adhesive layer.

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