An automatic reclosing protection device with lightning stroke counting function

Abstract

The application discloses an automatic reclosing protection device with lightning stroke counting function, comprising an AC-DC power supply circuit, a ground detection circuit, a current sampling control circuit, a voltage sampling circuit, a digital display circuit, a lightning stroke current detection circuit, a signal acquisition and holding circuit, a single-chip microcomputer and a peripheral circuit. The application has the beneficial effects that it can intelligently identify and distinguish power frequency ground leakage current and lightning stroke current, record the number of lightning strokes, avoid the misoperation of the protection device caused by lightning stroke current or other lightning induction, and avoid the problem of power outage or power shortage of the user end; the automatic reclosing protection device with lightning stroke counting function can solve the hidden dangers left by traditional air switches, leakage protection devices and ordinary automatic reclosing protection devices.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit, in particular to an automatic reclosing protection device with lightning stroke counting function. BACKGROUND

[0002] In the current security monitoring system, in the front-end power distribution box, a certain installation has ordinary air switch or air switch with leakage protection, and some installation has ordinary automatic reclosing protection device. They can meet some needs of users to some extent, but also bring some new problems, such as: air switch with leakage protection solves the danger of electric shock caused by leakage, but brings trouble to outdoor user maintenance and management. Once tripped, someone must be sent to the scene to handle manually. In addition, the outdoor lightning environment is severe, and leakage protection and ordinary automatic reclosing protection device are also easy to malfunction due to lightning. Because leakage protection and ordinary automatic reclosing protection device cannot identify power frequency leakage and ground lightning, as long as there is current flowing to the ground, leakage protection and ordinary automatic reclosing protection device will be tripped, causing frequent malfunction in the scene application scene, which brings great trouble to user power consumption.

[0003] Therefore, the prior art has defects and needs to be improved. SUMMARY

[0004] The purpose of the present application is to overcome the defects of the prior art, and provide an automatic reclosing protection device with lightning stroke counting function, which can identify and distinguish power frequency ground leakage and ground lightning current.

[0005] The technical scheme of the present application is as follows: the present application provides an automatic reclosing protection device with lightning stroke counting function, which comprises: an AC-DC power supply circuit, a ground detection circuit, a current sampling control circuit, a voltage sampling circuit, a digital display circuit, a lightning current detection circuit, a signal acquisition and retention circuit, a single-chip microcomputer and peripheral circuit, the ground detection circuit is electrically connected with the AC-DC power supply circuit, the signal acquisition and retention circuit and the lightning current detection circuit are electrically connected with the current sampling control circuit, and the current sampling control circuit, the signal acquisition and retention circuit, the lightning current detection circuit, the voltage sampling circuit, the AC-DC power supply circuit and the digital display circuit are electrically connected with the single-chip microcomputer and peripheral circuit.

[0006] The current sampling control circuit is used for sampling current and controlling power supply loop through a relay, the lightning current detection circuit is used for judging whether it is lightning current according to the detection result of the current sampling control circuit, the signal collection and holding circuit is used for judging whether it is power frequency to ground leakage and amplifying and peak holding corresponding signals according to the detection result of the current sampling control circuit, and the single-chip microcomputer and peripheral circuit are used for data processing, controlling the relay work of the current sampling control circuit and counting lightning events.

[0007] Further, the current sampling control circuit comprises a collection coil T2 used for collecting signal current, an output terminal P9 used for outputting voltage signals of the collection coil T2 to the signal collection and holding circuit and the lightning current detection circuit, and a relay K1 used for controlling the power supply loop.

[0008] When the power supply line does not occur leakage and lightning, the in and out current of the zero line and the fire line of the power supply line is equal, the magnetic field generated by the collection coil T2 is equal in size and opposite in direction and is offset to each other, and the output terminal P9 has no voltage signal output.

[0009] When the power supply line occurs leakage, the in and out current of the zero line and the fire line of the power supply line is not equal, the magnetic field generated by the collection coil T2 cannot be offset to each other, the output terminal P9 has voltage output to the signal collection and holding circuit, the signal collection and holding circuit amplifies and peak holds signals and sends to the single-chip microcomputer and peripheral circuit for AD data processing, when the data exceeds the set value, the single-chip microcomputer and peripheral circuit output voltage signals to drive the relay K1 to cut off the power supply loop; and the output voltage generated by the output terminal P9 when leakage is not enough to drive the photoelectric coupler U1 of the lightning current detection circuit, which will not cause the single-chip microcomputer and peripheral circuit to count lightning.

[0010] When lightning occurs, lightning current flows into the ground through lightning protection devices MOV1 and MOV2, the in and out current of the zero line and the fire line of the power supply line is not equal, the magnetic field generated by the collection coil T2 cannot be offset to each other, and the output terminal P9 has voltage signal output. Since the output voltage signal is bypassed through the capacitor C27 of the signal collection and holding circuit, the voltage signal output by the output terminal P9 drives the photoelectric coupler U1 of the lightning current detection circuit to work, the lightning current detection circuit sends signals to the single-chip microcomputer and peripheral circuit, and the single-chip microcomputer and peripheral circuit count and process lightning events.

[0011] The beneficial effects of the present invention by adopting the above solution are as follows: it can intelligently identify and distinguish between power frequency leakage current to ground and lightning strike current to ground, and record the number of lightning strikes, which can avoid the protection device from malfunctioning due to lightning strike current to ground or other lightning induction, and avoid the problem of power outage at the user end; the automatic reclosing protection device with lightning strike counting can solve the backdoors and hidden dangers left by traditional air switches, leakage protection devices, and ordinary automatic reclosing protection devices. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the principle of the present invention.

[0013] Figure 2 This is a circuit diagram of the current sampling control circuit of the present invention.

[0014] Figure 3 This is a circuit diagram of the lightning current detection circuit of the present invention.

[0015] Figures 4a to 4c This is a schematic diagram of the signal acquisition and holding circuit of the present invention.

[0016] Figure 5a and Figure 5b This is a schematic diagram of the voltage sampling circuit of the present invention.

[0017] Figure 6 This is a schematic diagram of the digital display circuit of the present invention.

[0018] Figure 7a and Figure 7b This is a schematic diagram of the AC-DC power supply circuit of the present invention.

[0019] Figure 8 This is a schematic diagram of the grounding detection circuit of the present invention.

[0020] Figures 9a to 9d This is a schematic diagram of the microcontroller and peripheral circuits of the present invention. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0022] Please refer to the following: Figures 1 to 9dIn the embodiment, the application provides an automatic reclosing protection device with lightning stroke counting function, comprising an AC-DC power supply circuit, a grounding detection circuit, a current sampling control circuit, a voltage sampling circuit, a digital display circuit, a lightning stroke current detection circuit, a signal acquisition and holding circuit, a single-chip microcomputer and a peripheral circuit, wherein the grounding detection circuit is electrically connected with the AC-DC power supply circuit, the signal acquisition and holding circuit and the lightning stroke current detection circuit are electrically connected with the current sampling control circuit, and the current sampling control circuit, the signal acquisition and holding circuit, the lightning stroke current detection circuit, the voltage sampling circuit, the AC-DC power supply circuit and the digital display circuit are electrically connected with the single-chip microcomputer and the peripheral circuit.

[0023] The current sampling control circuit is used for sampling current and controlling power supply loop through a relay; the lightning stroke current detection circuit is used for judging whether it is lightning stroke current according to the detection result of the current sampling control circuit and sending corresponding signal to the single-chip microcomputer and the peripheral circuit; the signal acquisition and holding circuit is used for judging whether it is power frequency to ground leakage according to the detection result of the current sampling control circuit, amplifying and peak holding corresponding signal and then sending signal to the single-chip microcomputer and the peripheral circuit; the single-chip microcomputer and the peripheral circuit are used for data processing, controlling the relay of the current sampling control circuit to work and counting lightning stroke events and driving the digital display circuit to work; the AC-DC power supply circuit is used for providing power required by the automatic reclosing protection device to work; the grounding detection circuit is used for grounding detection; the voltage sampling circuit is used for voltage sampling and sending to the single-chip microcomputer and the peripheral circuit; and the digital display circuit comprises a digital tube used for displaying lightning stroke quantity.

[0024] Further, the current sampling control circuit comprises an acquisition coil T2 used for acquiring signal current, an output terminal P9 used for outputting voltage signal of the acquisition coil T2 to the signal acquisition and holding circuit and the lightning stroke current detection circuit, and a relay K1 used for controlling power supply loop.

[0025] When there is no leakage and lightning stroke in the power supply line, the in-and-out current of the zero line and the fire line of the power supply line is equal, the magnetic field generated by the acquisition coil T2 is equal in size and opposite in direction and is offset to each other, and the output terminal P9 has no voltage signal output.

[0026] When the power supply line is electrified, the input and output current of the zero line and the fire line of the power supply line is not equal, the magnetic field generated by the collection coil T2 cannot be offset, the output terminal P9 has voltage output to the signal collection and holding circuit, the signal collection and holding circuit amplifies and peak holds the signal, and sends to the single-chip microcomputer and peripheral circuit for AD data processing, when the data exceeds the set value, the single-chip microcomputer and peripheral circuit output voltage signal to drive the relay K1 to cut off the power supply circuit, so that the electric shock accident can be avoided; and the output voltage generated by the output terminal P9 when electrified is not enough to drive the photoelectric coupler U1 of the lightning current detection circuit, and the single-chip microcomputer and peripheral circuit will not count the lightning.

[0027] When lightning occurs, the lightning current flows into the ground through the lightning protection device MOV1 and the lightning protection device MOV2, the input and output current of the zero line and the fire line of the power supply line is not equal, the magnetic field generated by the collection coil T2 cannot be offset, the output terminal P9 has voltage signal output, because the frequency spectrum of the lightning current is much larger than the 50Hz power frequency current, therefore the voltage signal output by the output terminal P9 bypasses the capacitor C27 of the signal collection and holding circuit, and cannot be amplified and peak held, therefore the signal will not be sent to the single-chip microcomputer and peripheral circuit to control the relay K1 to work, so that the misoperation of the automatic reclosing protection device caused by the lightning current can be avoided; because the duration of the lightning current is short but the current amplitude is large, the minimum value is 1KA, which is much larger than the power frequency electrified current (30mA), therefore the voltage signal output by the output terminal P9 drives the photoelectric coupler U1 of the lightning current detection circuit to work, the lightning current detection circuit sends a signal to the single-chip microcomputer and peripheral circuit, the single-chip microcomputer and peripheral circuit count the lightning events and control the digital display circuit to display the number of lightning.

[0028] In summary, the beneficial effects of the present application are that the power frequency ground electrification and the ground lightning current can be intelligently identified and distinguished, and the number of lightning is recorded, the misoperation of the protection device caused by the ground lightning current or other lightning induction can be avoided, and the problem of power outage of the user end can be avoided; the automatic reclosing protection device with lightning counting can solve the hidden dangers left by the traditional air switch, leakage protection and ordinary automatic reclosing protection device.

[0029] The above is only a preferred embodiment of the present application, and is not used to limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An automatic reclosing protection device with lightning strike counting function, characterized in that, include: The system comprises an AC-DC power supply circuit, a grounding detection circuit, a current sampling control circuit, a voltage sampling circuit, a digital display circuit, a lightning current detection circuit, a signal acquisition and holding circuit, a microcontroller, and peripheral circuits. The grounding detection circuit is electrically connected to the AC-DC power supply circuit. The signal acquisition and holding circuit and the lightning current detection circuit are both electrically connected to the current sampling control circuit. The current sampling control circuit, signal acquisition and holding circuit, lightning current detection circuit, voltage sampling circuit, AC-DC power supply circuit, and digital display circuit are all electrically connected to the microcontroller and peripheral circuits. The current sampling control circuit is used to sample the current and control the power supply circuit via a relay. The lightning current detection circuit is used to... The current sampling control circuit determines whether the current is a lightning strike current based on its detection result. The signal acquisition and holding circuit determines whether the current is a power frequency to ground leakage current based on the detection result of the current sampling control circuit and amplifies and holds the corresponding signal peak. The microcontroller and peripheral circuits are used for data processing, controlling the relay operation of the current sampling control circuit, and counting lightning strike events. The current sampling control circuit includes a sampling coil T2 for acquiring the signal current, an output terminal P9 for outputting the voltage signal of the sampling coil T2, a relay K1 for controlling the power supply circuit, a lightning protection device MOV1, and a lightning protection device MOV2. When there is no leakage current and no lightning strike occurs in the power supply line, the neutral and live wires of the power supply line... When the output currents are equal, the magnetic fields generated by the acquisition coil T2 are of the same magnitude but opposite in direction and cancel each other out, resulting in no voltage signal output from the output terminal P9. However, when a leakage occurs in the power supply line, the currents entering and exiting the neutral and live wires are unequal, and the magnetic fields generated by the acquisition coil T2 cannot cancel each other out. A voltage is output from the output terminal P9 to the signal acquisition and holding circuit. The signal acquisition and holding circuit amplifies the signal and holds its peak value, then sends it to the microcontroller and peripheral circuits for AD data processing. When the data exceeds a set value, the microcontroller and peripheral circuits output a voltage signal to drive the relay K1 to cut off the power supply circuit. The output voltage generated by the output terminal P9 during leakage is insufficient to drive the relay. The optocoupler U1 in the lightning current detection circuit does not count lightning strikes. When a lightning strike occurs, the lightning current flows into the ground through the surge protection devices MOV1 and MOV2. The currents entering and exiting the neutral and live wires of the power supply line are not equal, and the magnetic fields generated by the acquisition coil T2 cannot cancel each other out. The output terminal P9 outputs a voltage signal. The voltage signal output from the output terminal P9 is bypassed by the capacitor C27 of the signal acquisition and holding circuit, and cannot be amplified or held at the peak value. The voltage signal output from the output terminal P9 drives the optocoupler U1 of the lightning current detection circuit to work. The lightning current detection circuit sends a signal to the microcontroller and peripheral circuits, and the microcontroller and peripheral circuits count the lightning strike events.

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