A gas discharge tube life detection device and method

Abstract

The present invention provides a gas discharge tube life detection device and method, including: a light collection circuit, a control circuit; the light collection circuit is connected to the control circuit; the light collection circuit is used to collect the light intensity signal emitted when the gas discharge tube is struck by lightning, and convert it into an electrical signal that can be collected by the control circuit; the control circuit is used to process the electrical signal generated by the light collection circuit, and then obtain the number of lightning strikes and the value of the lightning current of the gas discharge tube. The present invention uses the characteristic that the gas discharge tube will generate arc light / glow when passing through the lightning current, collects the light intensity of the gas discharge tube when it is struck by lightning through a photosensitive diode, and counts the number of lightning strikes on the discharge tube, the current size of the lightning strike, and other information to indirectly determine the life of the gas discharge tube.

Description

Technical Field

[0001] The present invention relates to the technical field of lightning protection, and in particular to a gas discharge tube life detection device and method. Background Art

[0002] In the lightning protection industry, commonly used lightning protection components are varistors and gas discharge tubes. Varistors are voltage-limiting devices. When lightning current passes through them, they generate heat. The change in their own temperature can be used to determine whether lightning current is flowing, and then determine their lifespan, or the thermal release device can indicate. However, gas discharge tubes are switch-type devices with only two states: disconnected and on. When lightning current flows through them, the heat generated is very low. Therefore, it is basically not feasible to detect them in a similar way to varistor heating. Gas discharge tubes are the most commonly used signal lightning protection products, so it is particularly important to detect whether gas discharge tubes have failed.

[0003] The inside of the gas discharge tube is filled with inert gas with stable electrical properties, and is connected to the circuit that needs to be protected. When a certain voltage is applied to both ends of the discharge tube, the inert gas inside the discharge tube begins to be freed under the influence of the electric field. When the voltage exceeds the insulation strength of the gas, the gap between the discharge tube electrodes is broken down by discharge, and the discharge tube changes from the original open circuit state to a short circuit state, thereby discharging large currents and limiting voltages, thereby protecting the back-end equipment.

[0004] Based on the electrical characteristics of gas discharge tubes, in existing technologies, the performance test of gas discharge tubes is basically carried out using a lightning protection component tester. However, due to the limitations of size and cost, the lightning protection component tester cannot achieve real-time detection of gas discharge tubes in actual application circuits, that is, real-time monitoring on the circuit. Summary of the invention

[0005] In view of the defects in the prior art, the purpose of the present invention is to provide a gas discharge tube life detection device and method. The technical solution of the present invention is as follows:

[0006] A gas discharge tube life detection device comprises: a light collection circuit and a control circuit; the light collection circuit is connected to the control circuit; wherein:

[0007] A light collection circuit is used to collect the light intensity signal emitted by the gas discharge tube when it is struck by lightning, and convert it into an electrical signal that can be collected by the control circuit;

[0008] The control circuit is used to process the electrical signal generated by the light collection circuit, so as to obtain the number of lightning strikes and the lightning current value of the gas discharge tube.

[0009] Optionally, the light collection circuit includes: a photosensitive diode D1, a first resistor R1, a second resistor R2, a transistor Q1, and a third resistor R3; wherein:

[0010] The anode of D1 is connected to the first end of R2 and the base of Q1 respectively; the cathode of D1 is connected to the second end of R1 and the control circuit respectively; the collector of Q1 is connected to the second end of R3 and the control circuit; the emitter of Q1 is grounded; the first end of R1 is connected to the first power supply; the second end of R2 is grounded; the first end of R3 is connected to the second power supply.

[0011] Optionally, the control circuit includes: a signal amplification subcircuit and a single chip microcomputer; wherein:

[0012] The cathode of the photodiode D1 is connected to the signal amplification subcircuit; the signal amplification subcircuit is connected to the AD port of the single-chip microcomputer; the collector of the transistor Q1 is connected to the I / O port of the single-chip microcomputer;

[0013] The signal amplification subcircuit obtains the voltage analog signal of the photodiode D1 and amplifies it, and then provides it to the single chip microcomputer for AD acquisition;

[0014] The single-chip microcomputer calculates the number of lightning strikes on the gas discharge tube through the signal input of the I / O port; the single-chip microcomputer collects the voltage value change of the gas discharge tube when it is struck by lightning through the signal input of the AD port, and then determines the size of the lightning current; and the single-chip microcomputer determines the degree of degradation of the gas discharge tube by counting the number of lightning strikes on the gas discharge tube and the size of the lightning current flowing through.

[0015] Optionally, the signal amplification subcircuit further includes:

[0016] A fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first operational amplifier AMP1, and a second operational amplifier AMP2; wherein:

[0017] The first end of R4 is connected to the second end of R1; the second end of R4 is respectively connected to the negative input end of AMP1 and the first end of R6; the first end of R5 is connected to the positive input end of AMP1, and the second end of R5 is grounded; the second end of R6 is respectively connected to the output end of AMP1 and the negative input end of AMP2; the positive input end of AMP2 is respectively connected to the output end of AMP2 and the first end of R7; the second end of R7 is respectively connected to the AD port of the microcontroller and the first end of R8; the second end of R8 is grounded.

[0018] Optionally, the device further comprises: a display unit connected to the control circuit; the display unit is used to display the number of lightning strikes, lightning strike time, lightning strike current value, and degradation degree of the gas discharge tube.

[0019] Optionally, the display unit includes: a PC; and the single chip microcomputer is connected to the PC.

[0020] A gas discharge tube life detection method, applied to the above-mentioned device, comprises the following steps:

[0021] Sl: The gas generator tube is struck by lightning;

[0022] S2: D1 is turned on, Q1 is turned on, and two signals are generated, which are sent to the AD port and I / O port of the microcontroller respectively;

[0023] S3: The microcontroller calculates the number of lightning strikes through the I / O port input;

[0024] S4: The single-chip microcomputer collects the voltage value change of the gas discharge tube when it is struck by lightning through the signal input of the AD port, and then determines the magnitude of the lightning current; and the single-chip microcomputer determines the degree of deterioration of the gas discharge tube by counting the number of times the gas discharge tube is struck by lightning and the magnitude of the lightning current flowing through;

[0025] S5: The single chip microcomputer sends the information of the number of lightning strikes, lightning current, lightning strike time, and the degree of degradation of the gas discharge tube to the PC for display.

[0026] Optionally, before step S4, the following steps are also included:

[0027] The relationship between the voltage value of the gas discharge tube when it is struck by lightning and the value of the lightning current is obtained in advance.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention uses the characteristic that a gas discharge tube will generate arc light / glow when a lightning current passes through it, collects the light intensity of the gas discharge tube when it is struck by lightning through a photosensitive diode, counts the number of times the discharge tube is struck by lightning, the current size of the lightning strike and other information, and indirectly determines the life of the gas discharge tube, thereby realizing real-time detection of the gas discharge tube in an actual application circuit; and the present invention also has the advantages of high detection accuracy, simple structure, low cost and easy implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0031] Figure 1 It is a structural schematic diagram of a gas discharge tube life detection device according to a specific embodiment of the present invention;

[0032] Figure 2 is a circuit diagram of a signal amplification subcircuit according to a specific embodiment of the present invention;

[0033] Figure 3 It is a connection diagram of a display unit according to a specific embodiment of the present invention. DETAILED DESCRIPTION

[0034] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0035] See Figure 1- Figure 3 , This embodiment discloses a gas discharge tube life detection device, including: a light collection circuit, a control circuit, and a display unit; the light collection circuit, the control circuit, and the display unit are connected in sequence;

[0036] in:

[0037] A light collection circuit is used to collect the light intensity signal emitted by the gas discharge tube when it is struck by lightning, and convert it into an electrical signal that can be collected by the control circuit;

[0038] The control circuit is used to process the electrical signal generated by the light collection circuit, so as to obtain the number of lightning strikes and the lightning current value of the gas discharge tube.

[0039] The display unit is used to display the number of lightning strikes, lightning strike time, lightning strike current, and the degree of deterioration of the gas discharge tube.

[0040] It should be noted that one of the important phenomena of gas discharge is glow / arc discharge. This embodiment utilizes the characteristic that when the gas inside the gas discharge tube is struck by lightning, it breaks down and discharges, causing glow / arc discharge. By collecting the light intensity of the glow / arc discharge (i.e., the light intensity signal), it is determined whether a lightning strike occurs and the size of the lightning current.

[0041] The gas discharge tube is arranged at two ends X1 and X2 of the circuit to be protected to form a discharge tube protection circuit.

[0042] The light collection circuit includes: a photosensitive diode D1, a first resistor R1, a second resistor R2, a transistor Q1, and a third resistor R3; R1 is a current limiting resistor, R2 is a voltage dividing resistor, and R3 is a pull-up resistor. In this embodiment, the distance between the photosensitive diode and the gas discharge tube is 3 mm. This is only an example, and the present invention does not limit the distance.

[0043] in:

[0044] The anode of D1 is connected to the first end of R2 and the base of Q1 respectively; the cathode of D1 is connected to the second end of R1 and the control circuit respectively; the collector of Q1 is connected to the second end of R3 and the control circuit; the emitter of Q1 is grounded; the first end of R1 is connected to the first power supply; the second end of R2 is grounded; the first end of R3 is connected to the second power supply. In this embodiment, the first power supply is 5V and the second power supply is 3.3V. This is just an example, and the present invention does not limit the values ​​of the first power supply and the second power supply.

[0045] When there is no lightning current impact, the gas discharge tube in the discharge tube protection circuit does not break down, the photosensitive diode D1 does not detect the light source, D1 is cut off, the transistor Q1 is also cut off, and the collector (C pole) of the transistor Q1 outputs a high level due to the existence of the R3 pull-up resistor; when there is a lightning current impact, the gas discharge tube in the discharge tube protection circuit is broken down, and the breakdown process produces a glow arc phenomenon. After the photosensitive diode detects the light, the diode D1 is turned on, R1, D1, and R2 are voltage-divided, the base and emitter (BE pole) of the transistor Q1 are forward-conducted, and the collector outputs a low level.

[0046] The control circuit includes: a signal amplification subcircuit and a single-chip microcomputer; in this embodiment, the single-chip microcomputer model is STM32F103C8T6. This is only an example, and the present invention does not limit the model of the single-chip microcomputer.

[0047] in:

[0048] The cathode of the photodiode D1 is connected to the signal amplification subcircuit; the signal amplification subcircuit is connected to the AD port of the single-chip microcomputer; the collector of the transistor Q1 is connected to the I / O port of the single-chip microcomputer;

[0049] The signal amplification subcircuit obtains the voltage analog signal of the photodiode D1 and amplifies it, and then provides it to the single chip microcomputer for AD acquisition;

[0050] The single-chip microcomputer calculates the number of lightning strikes on the gas discharge tube through the signal input of the I / O port; the single-chip microcomputer collects the voltage value change of the gas discharge tube when it is struck by lightning through the signal input of the AD port, and then determines the size of the lightning current; and the single-chip microcomputer determines the degree of degradation of the gas discharge tube by counting the number of lightning strikes on the gas discharge tube and the size of the lightning current flowing through.

[0051] In the light collection circuit, there are two signals sent to the control circuit. One of them is the logic high and low level (defined as DI here) output by the collector (C pole) of the transistor Ql, which is directly sent to the I / O port of the microcontroller; the other is the voltage analog signal of the photodiode D1. The analog signal needs to be processed to obtain the voltage signal (defined as AI here) and then sent to the AD port of the microcontroller.

[0052] Since the impact time of lightning current in the line is extremely short, the logic level detection of the single-chip microcomputer adopts the interrupt detection method, which saves the hardware resources of the single-chip microcomputer on the one hand and improves the detection speed on the other hand. For the acquisition of analog voltage, the DMA method is adopted, and the threshold level is set. Once the voltage exceeds the threshold voltage, the single-chip microcomputer reads the result of AD conversion from the memory and determines the voltage value. In this way, DI is used to detect whether a lightning strike has occurred, and AI is used to determine the size of the lightning current. It should be noted that setting the threshold level is only an optional processing method, the purpose of which is to reduce the resource consumption of the single-chip microcomputer. In other embodiments, the threshold value may not be set, and the full acquisition method may be adopted. Therefore, the present invention does not limit the specific working method of the single-chip microcomputer.

[0053] Among them, Figure 2 , the signal amplification subcircuit further comprises:

[0054] A fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first operational amplifier AMP1, and a second operational amplifier AMP2; wherein:

[0055] The first end of R4 is connected to the second end of R1; the second end of R4 is respectively connected to the negative input end of AMP1 and the first end of R6; the first end of R5 is connected to the positive input end of AMP1, and the second end of R5 is grounded; the second end of R6 is respectively connected to the output end of AMP1 and the negative input end of AMP2; the positive input end of AMP2 is respectively connected to the output end of AMP2 and the first end of R7; the second end of R7 is respectively connected to the AD port of the microcontroller and the first end of R8; the second end of R8 is grounded.

[0056] In the signal processing circuit, Ui is the cathode voltage value of the photodiode, which is amplified in two stages. In the first stage, the operational amplifier AMP1, resistors R4, R5, and R6 form a reverse proportional operational amplifier circuit, and the second stage operational amplifier forms a voltage follower to achieve an isolation effect. Since the reference voltage of the microcontroller is 3.3V, the output Uo of the operational amplifier is divided by two resistors R7 and R8, and then sent to the AD port of the microcontroller.

[0057] like Figure 3 , wherein the display unit includes: a PC; the single-chip microcomputer is connected to the PC. In specific implementation, the two are not directly connected, but connected in the following way: the single-chip microcomputer is connected to a 485-to-Ethernet device via RS485, the 485-to-Ethernet device is connected to a switch via a network cable, and the switch is connected to the PC via a network cable. The switch is a commonly used network switch. The PC is installed with iCore Manage management software. Wherein, SPD is a surge protector.

[0058] The design idea of ​​this embodiment is based on the research and demonstration of the glow arc discharge tube based on the Townsend theory. The theory verifies that different gap media have different critical breakdown electric field strengths Ec. When the electric field E in the gap is lower than Ec, the gap will not break down. In the Townsend discriminant, the ionization coefficient α increases with the increase of the external electric field strength E, and the ionization effect of the electrons is also enhanced. Based on this idea, when the gas discharge tube is impacted by lightning currents of different sizes, different light intensities will be generated, and the intensity of the light will increase with the increase of the lightning current, and a certain relationship will be satisfied. It can be considered that the voltage value of the gas discharge tube when it is impacted by lightning and the value of the lightning current satisfy a certain relationship.

[0059] The relationship between the voltage value of the gas discharge tube when it is struck by lightning and the value of the lightning current can be obtained in advance. The method of obtaining the relationship can be to conduct a large number of tests, and find out the experimental regularity between the light intensity emitted by the gas discharge tube when it is struck and the magnitude of the lightning current by statistical methods, so as to obtain the relationship between the voltage value of the gas discharge tube when it is struck by lightning and the value of the lightning current. In other embodiments, the relationship between the two can also be obtained by other methods, which are not limited by the present invention.

[0060] The single chip microcomputer can calculate the corresponding lightning current value through the voltage value according to the above relationship. The larger the voltage value, the greater the light intensity, and the more serious the lightning strike.

[0061] The control circuit sends the collected lightning strike information (whether there is lightning strike, the size of lightning strike current) to the 485 to Ethernet device through the R485 interface, and then uploads it to the PC through the switch. The number of lightning strikes during the operation of the equipment, the time of the lightning strike, the size of the lightning strike current, and the degree of degradation of the gas discharge tube are displayed on the PC screen.

[0062] This embodiment also discloses a gas discharge tube life detection method, which is applied to the above-mentioned device and includes the following steps:

[0063] S1: The gas generator tube is struck by lightning;

[0064] S2: D1 is turned on, Q1 is turned on; two signals are generated, which are input from the AD port and I / O port of the microcontroller respectively;

[0065] S3: The microcontroller calculates the number of lightning strikes through the I / O port input;

[0066] S4: The single-chip microcomputer collects the voltage value change of the gas discharge tube when it is struck by lightning through the signal input of the AD port, and then determines the magnitude of the lightning current; and the single-chip microcomputer determines the degree of deterioration of the gas discharge tube by counting the number of times the gas discharge tube is struck by lightning and the magnitude of the lightning current flowing through;

[0067] S5: The single chip microcomputer sends the information of the number of lightning strikes, lightning current, lightning strike time, and the degree of degradation of the gas discharge tube to the PC for display.

[0068] Before step S4, the method further includes the following steps:

[0069] The relationship between the voltage value of the gas discharge tube when it is struck by lightning and the value of the lightning current is obtained in advance.

[0070] This embodiment collects arc light when the gas discharge tube is struck by lightning during operation, and performs statistics on the number of lightning strikes / lightning current, so as to indirectly determine the performance of the discharge tube. When the number of lightning strikes exceeds a certain value (defined in the technical specification of the discharge tube), it is considered that the performance of the discharge tube has deteriorated, and the user is prompted through the PC to replace it, so as to ensure that the back-end equipment is well protected.

[0071] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A gas discharge tube life detection device, characterized in that: include: A light collection circuit, a control circuit and a display unit; the light collection circuit and the display unit are connected to the control circuit respectively; wherein: The light collection circuit is used to collect the light intensity signal emitted by the gas discharge tube when it is struck by lightning, and convert it into an electrical signal that can be collected by the control circuit; The light collection circuit includes: a photosensitive diode D1, a first resistor R1, a second resistor R2, a transistor Q1, and a third resistor R3; wherein: The anode of D1 is connected to the first end of R2 and the base of Q1 respectively; the cathode of D1 is connected to the second end of R1 and the control circuit respectively; the collector of Q1 is connected to the second end of R3 and the control circuit; the emitter of Q1 is grounded; the first end of R1 is connected to the first power supply; the second end of R2 is grounded; the first end of R3 is connected to the second power supply; The control circuit is used to process the electrical signal generated by the light collection circuit, thereby obtaining the number of lightning strikes and the lightning current value of the gas discharge tube; The control circuit comprises: a signal amplification subcircuit and a single chip microcomputer; wherein: The cathode of the photodiode D1 is connected to the signal amplification subcircuit; the signal amplification subcircuit is connected to the AD port of the single-chip microcomputer; the collector of the transistor Q1 is connected to the I / O port of the single-chip microcomputer; The signal amplification subcircuit obtains the voltage analog signal of the photodiode D1 and amplifies it, and then provides it to the single-chip microcomputer for AD acquisition; the single-chip microcomputer calculates the number of lightning strikes on the gas discharge tube through the signal input of the I / O port; the single-chip microcomputer collects the voltage value change of the gas discharge tube when it is struck by lightning through the signal input of the AD port, and then determines the size of the lightning current; and the single-chip microcomputer determines the degree of degradation of the gas discharge tube by counting the number of lightning strikes on the gas discharge tube and the size of the lightning current flowing through it; The signal amplification subcircuit further comprises: A fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first operational amplifier AMP1, and a second operational amplifier AMP2; wherein: The first end of R4 is connected to the second end of R1; the second end of R4 is respectively connected to the negative input end of AMP1 and the first end of R6; the first end of R5 is connected to the positive input end of AMP1, and the second end of R5 is grounded; the second end of R6 is respectively connected to the output end of AMP1 and the negative input end of AMP2; the positive input end of AMP2 is respectively connected to the output end of AMP2 and the first end of R7; the second end of R7 is respectively connected to the AD port of the single-chip computer and the first end of R8; the second end of R8 is grounded; The display unit is used to display the number of lightning strikes, the lightning strike time, the lightning strike current value, and the degree of deterioration of the gas discharge tube.

2. The device according to claim 1, characterized in that The display unit comprises: a PC; the single chip microcomputer is connected to the PC.

3. A method for detecting the life of a gas discharge tube, characterized in that: The device according to any one of claims 1 to 2 comprises the following steps: S1: The gas generator tube is struck by lightning; S2: D1 is turned on, Q1 is turned on, and two signals are generated, which are sent to the AD port and I / O port of the microcontroller respectively; S3: The microcontroller calculates the number of lightning strikes through the I / O port input; S4: The single-chip microcomputer collects the voltage value change of the gas discharge tube when it is struck by lightning through the signal input of the AD port, and then determines the magnitude of the lightning current; and the single-chip microcomputer determines the degree of deterioration of the gas discharge tube by counting the number of times the gas discharge tube is struck by lightning and the magnitude of the lightning current flowing through; S5: The single chip microcomputer sends the information of the number of lightning strikes, lightning current, lightning strike time, and the degree of degradation of the gas discharge tube to the PC for display.

4. The method according to claim 3, characterized in that Before step S4, the method further includes the following steps: The relationship between the voltage value of the gas discharge tube when it is struck by lightning and the value of the lightning current is obtained in advance.

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