Grounding-free anti-surge anti-interference protector for electric power station area metering information acquisition system

Abstract

The utility model relates to the technical field of electric power station area metering acquisition, in particular to a non-grounding anti-surge anti-interference protector for an electric power station area metering information acquisition system, which consists of a power supply channel surge and interference protection circuit, an acquisition signal channel surge and interference protection circuit, a high-capacity surge energy storage pool circuit and a lightning stroke surge monitoring circuit. The lightning protection device is used for protecting the information acquisition equipment from being damaged by lightning surge or interference introduced from the field.

Description

Technical Field

[0001] The utility model relates to the technical field of power substation metering and collection, and specifically relates to a groundless surge and interference-proof protector for a power substation metering information collection system. Background Art

[0002] With the widespread application of modern smart grid automatic meter reading technology, a large number of power metering information collection equipment have been installed on-site in the power user areas of various industries. The collection equipment is installed in a harsh environment and has a wide distribution area. Most of its power supply and metering signals are transmitted via overhead lines, which are easily introduced by surges and interference such as lightning induction, operational overvoltage, and high current power load startup. The collection equipment has a low impact voltage resistance level and poor protection against surges and interference. Once surges and interference are introduced by the line, they are easily damaged, resulting in communication interruption and equipment failure, causing huge economic losses to equipment and metering.

[0003] The widespread application of the metering information collection system in power substations has brought great convenience to people's production and life, and saved a lot of labor and management costs for power management departments. However, with the widespread application of the metering information collection system, incidents of damage to the collection system and meters due to lightning surges and interference have occurred from time to time, which has become an important factor affecting the safe operation of the metering information collection system in power substations. Therefore, in order to ensure the safe and reliable operation of the metering information collection system in power substations and reduce unnecessary economic losses, it is necessary to take protective measures such as surge protection and interference protection for the metering information collection system.

[0004] At present, the traditional surge protection methods of the power substation metering information collection system are mainly the following:

[0005] 1: Simply install a signal lightning arrester at the signal port of the information collection equipment. The technical features of the signal lightning arrester are as follows:

[0006] The signal lightning arrester is mainly composed of TVS, which uses common mode protection or differential mode protection, or a combination of common and differential mode protection to protect the line from overvoltage. The advantage of TVS is that it has a fast response time (≤1ns), and the disadvantage is that the lightning surge current capacity is small (1-3kA@8 / 20us). For the relatively large lightning surges and interference introduced by overhead lines, the surge protection effect is poor and the anti-interference ability is poor. When a slightly larger lightning induced surge or interference occurs, it is very easy to cause a breakdown short circuit, which cannot effectively protect the metering information acquisition system equipment and affect the operation of the equipment. This type of signal lightning arrester also needs to be connected to the lightning protection grounding network that meets the grounding resistance requirements with a grounding wire to form the function of surge overvoltage protection. If the grounding wire is not connected, it will not have surge protection capability or the surge protection capability will be very weak.

[0007] 2. Install a power surge protector at the power port of the information collection device. The technical features of the power surge protector are as follows:

[0008] Two varistors are used inside the power supply lightning arrester to connect between the L and N terminals of the power supply and the ground, and common mode protection is used for the power interface to achieve surge protection. The advantage is that the structure is simple and easy to install, and the disadvantage is that there is only common mode protection, no differential mode protection; there is leakage current between the varistor and the ground, and the leakage current will increase over time, which poses an unsafe hazard to the use of the power supply system; the lightning impulse residual voltage is high (Up: 1.5kV), the lightning impulse current capacity is small (Imax: 20kA@8 / 20us), and it cannot effectively protect against various surge and clutter interference introduced by the power supply line, which poses a great hazard to the stability of the power supply system operation. This type of power supply lightning arrester also needs to be connected to a lightning protection grounding network that meets the grounding resistance requirements with a grounding wire to form the function of surge overvoltage protection. If there is no grounding wire, it will not have surge protection capability or the surge protection capability will be very weak.

[0009] 3. Install a two-in-one lightning arrester for power and signal at the power and signal ports of the information collection equipment. The technical characteristics of this lightning arrester are just a simple combination of the functions of the two lightning arresters mentioned in the first and second parts. It still has the disadvantages of poor surge protection, poor anti-interference ability, leakage current to the ground, and the need to use a grounding wire to connect to the lightning protection grounding network. If the grounding wire is not used, it will not have surge protection or the surge protection ability will be very weak.

[0010] 4. Install a ground-free power signal two-in-one lightning arrester at the power and signal ports of the information collection equipment. The technical feature of this lightning arrester is that it can achieve surge protection function without using a ground wire to connect to the lightning protection grounding network. Although it claims that it can do without a ground wire, its power line lightning impulse current capacity is small (Imax: 20kA@8 / 20us), lightning impulse residual voltage is high (Up: 1.5kV), signal line lightning impulse current capacity is small (Imax: 5kA@8 / 20us), lightning impulse residual voltage is high (Up: 280V), power and signal common mode surge absorption capacitor capacity is small (22uF / 400V), and surge absorption energy is limited. For strong surges or strong interference introduced through overhead lines, it cannot effectively protect the metering information collection system equipment, and there are still shortcomings such as poor surge protection capability and poor anti-interference capability.

[0011] The important common disadvantages of the surge protection methods of the above-mentioned power substation metering information collection system are: the surge protection effect of the lightning arrester is poor, the anti-interference ability is poor; there is leakage current to the ground; the lightning impulse current capacity is small; the lightning impulse residual pressure is high; the shell is made of plastic material and has no protection effect on interference signals. Signal lightning arresters, power lightning arresters and power signal two-in-one lightning arresters must be connected to the lightning protection grounding network that meets the grounding resistance requirements through the grounding wire to have the ability to protect against surge overvoltage and other disadvantages. For widely distributed information collection equipment and collection points where grounding conditions do not allow, if a lightning protection grounding network that meets the grounding resistance requirements is added, the implementation cost of the lightning protection grounding will be much higher than the cost of the protected equipment, and it will lose the value of large-scale promotion and use. The above-mentioned lightning arrester only has a simple surge protection function and does not have a lightning surge monitoring function. It is impossible to understand the use status of the lightning arrester in the power management room and implement remote monitoring. Utility Model Content

[0012] In view of the shortcomings of the prior art, the purpose of the utility model is to provide a groundless surge and anti-interference protector for an electric power substation metering information collection system, which can simultaneously protect the power port and the collection signal port of the information collection equipment. It is equipped with three-level surge overvoltage protection, two-level anti-interference harmonic filtering network circuit, large-capacity surge energy storage pool circuit, and a groundless surge and anti-interference protector with lightning surge monitoring function, which is used to protect the information collection equipment from damage caused by lightning surges or interference introduced from the site.

[0013] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a groundless surge and interference protector for an electric power substation metering information collection system, comprising a power supply channel surge and interference protection circuit, an acquisition signal channel surge and interference protection circuit, a large-capacity surge energy storage pool circuit, and a lightning surge monitoring circuit.

[0014] The power channel surge and interference protection circuit is provided with a power input terminal for connecting to a power source and a power output terminal connected to an information collector device;

[0015] The acquisition signal channel surge and interference protection circuit is provided with a signal input terminal for connecting to a signal and a signal output terminal connected to an information collector device;

[0016] The power channel surge and interference protection circuit includes a common differential mode power protection circuit composed of a three-stage varistor arranged between the power input terminal and the power output terminal, a common differential mode anti-interference harmonic filter network circuit composed of a two-stage inductor and capacitor, and a power startup overcurrent buffer circuit;

[0017] Two anti-interference harmonic filter network circuits are respectively matched and arranged between two adjacent power protection circuits, and an overcurrent buffer circuit is arranged between the power protection circuit at the end and the power output terminal;

[0018] The acquisition signal channel surge and interference protection circuit includes a three-level signal protection circuit and a surge energy matching circuit arranged between the signal input end and the signal output end, and the surge energy matching circuit is matched and arranged between the two-level signal protection circuits at the front end;

[0019] The large-capacity surge energy storage tank circuit is connected in series between the common-mode protection common end of the common-differential-mode power protection circuit composed of three-level varistors and the common-mode protection common end of the three-level signal protection circuit;

[0020] The collection end of the lightning surge monitoring circuit is respectively connected to the corresponding collection points on the power channel surge and interference protection circuit and the collection signal channel surge and interference protection circuit, and the output end of the lightning surge monitoring circuit is connected to the signal output end.

[0021] In some of the embodiments, the common differential mode power supply protection circuit composed of three-level varistors includes a first-level power supply protection circuit, a second-level power supply protection circuit and a third-level power supply protection circuit.

[0022] The common differential mode anti-interference harmonic filter network circuit composed of two-stage inductance and capacitance includes a first-stage harmonic filter network circuit and a second-stage harmonic filter network circuit.

[0023] The power input terminal, the first-level power protection circuit, the first-level harmonic filter network circuit, the second-level power protection circuit, the second-level harmonic filter network circuit, the third-level power protection circuit, the power startup overcurrent buffer circuit and the power output terminal are connected in sequence.

[0024] In some embodiments, a temperature protection circuit is connected in series in the first-level protection circuit of the power supply.

[0025] In some of the embodiments, the three-level signal protection circuit includes a first-level signal protection circuit, a second-level signal protection circuit and a third-level signal protection circuit.

[0026] The signal input terminal, the first-level signal protection circuit, the surge energy coordination circuit, the second-level signal protection circuit, the third-level signal protection circuit and the signal output terminal are connected in sequence.

[0027] In some embodiments, the first-level signal protection circuit is composed of a common-mode and differential-mode protection circuit consisting of a discharge tube; the second-level signal protection circuit is composed of a common-mode and differential-mode protection circuit consisting of a TVS tube; and the third-level signal protection circuit is composed of a common-mode and differential-mode protection circuit consisting of a discharge tube.

[0028] In some embodiments, the large-capacity surge energy storage tank circuit includes two groups of surge energy storage tank circuits, one group of surge energy storage tank circuits is connected to the common mode protection common end of the power supply channel surge and interference protection circuit, and the other group of surge energy storage tank circuits is connected to the common mode protection common end of the acquisition signal channel surge and interference protection circuit, and the common end of the two groups of surge energy storage tank circuits is connected in series to the virtual ground end.

[0029] In some of the embodiments, the lightning surge monitoring circuit is provided with a power supply circuit, a surge data acquisition circuit, a data processing and storage circuit, and a data transmission circuit;

[0030] The power supply circuit is connected to the power output terminal and supplies power to the surge data acquisition circuit, the data processing and storage circuit, and the data transmission circuit;

[0031] The surge data acquisition circuit acquires the status and surge data of the power supply channel and the signal channel, and is connected to the data processing and storage circuit;

[0032] The data processing and storage circuit processes and stores the collected power channel and signal channel states and surge data, and is connected to the data transmission circuit;

[0033] The data transmission circuit is connected to the signal output terminal.

[0034] In some of the embodiments, the power supply circuit includes a micro AC-DC isolation module, the input end of the micro AC-DC isolation module is connected to the output end of the power supply, and the output end of the micro AC-DC isolation module supplies power to each module of the lightning surge monitoring circuit.

[0035] In some of the embodiments, a power supply / degradation indication circuit is also provided on the first-level power supply protection circuit.

[0036] Compared with the prior art, the beneficial effects of the utility model are: it can simultaneously protect the power port and the acquisition signal port of the information acquisition equipment, and is equipped with three-level surge overvoltage protection, two-level anti-interference harmonic filtering network, large-capacity surge energy storage pool circuit, and groundless surge and anti-interference protector with lightning surge monitoring function, which is used to protect the information acquisition equipment from damage caused by lightning surges or interference introduced from the site.

[0037] Details of one or more embodiments of the present application are presented in the following drawings and descriptions to make other features, purposes and advantages of the present application more concise and understandable. The present application is fully described and understood through the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of module connection of the utility model;

[0039] Figure 2 This is a circuit schematic diagram of the utility model.

[0040] In the figure: 1. Power channel surge and interference protection circuit; 2. Power input terminal; 3. Power first-level protection circuit; 4. First-level harmonic filter network circuit; 5. Power second-level protection circuit; 6. Second-level harmonic filter network circuit; 7. Power third-level protection circuit; 8. Power startup overcurrent buffer circuit; 9. Power output terminal; 10. Lightning surge monitoring circuit; 11. Acquisition signal channel surge and interference protection circuit; 12. Signal input terminal; 13. Signal first-level protection circuit; 14. Surge energy coordination circuit; 15. Signal second-level protection circuit; 16. Signal third-level protection circuit; 17. Signal output terminal; 18. Power / degradation indication circuit; 19. Surge energy storage tank circuit;

[0041] M1-M13: varistor; T1-T3: temperature fuse; L1-L2: common mode filter coil; L3-L4: current sensor coil; RD1: NTC resistor; R1-R4: ordinary resistor; R5-R6: power winding resistor; DB1: rectifier bridge; D1-D2, rectifier diode; D3-D8: fast diode; D9: TVS transient diode; G1-G3: gas discharge tube; C1, C2, C4, C5: common mode capacitor; C3, C6: differential mode capacitor; C7-C9: electrolytic capacitor. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0043] The utility model aims to solve the problem of the on-site surge interference protection effect of the existing power station area metering information collection system, especially the metering information collection equipment. Embodiment 1

[0044] See also Figure 1-2The utility model provides a technical solution: a groundless surge and interference protection device for the metering information collection system of an electric power substation, including a power channel surge and interference protection circuit, a collection signal channel surge and interference protection circuit, a large-capacity surge energy storage pool circuit, and a lightning surge monitoring circuit. It adopts a closed metal rail mounting housing, and is internally encapsulated with epoxy resin. The protection level reaches IP65, which enhances the insulation, moisture-proof and anti-interference performance of the product, and is easy to install and has reliable performance. The power channel surge and interference protection circuit and the collection signal channel surge and interference protection circuit are combined into an integrated type, and pre-wiring is led out from both ends to connect the power end and signal end of the collection device / metering device, which is convenient for product installation;

[0045] The power channel surge and interference protection circuit is provided with a power input terminal for connecting to a power source and a power output terminal connected to an information collector device;

[0046] The acquisition signal channel surge and interference protection circuit is provided with a signal input terminal for connecting to a signal and a signal output terminal connected to an information collector device;

[0047] The power channel surge and interference protection circuit includes a common differential mode power protection circuit composed of a three-stage varistor arranged between the power input terminal and the power output terminal, a common differential mode anti-interference harmonic filter network circuit composed of a two-stage inductor and capacitor, and a power startup overcurrent buffer circuit;

[0048] Two anti-interference harmonic filter network circuits are respectively matched and arranged between two adjacent power protection circuits, and an overcurrent buffer circuit is arranged between the power protection circuit at the end and the power output terminal;

[0049] The acquisition signal channel surge and interference protection circuit includes a three-level signal protection circuit and a surge energy matching circuit arranged between the signal input end and the signal output end, and the surge energy matching circuit is matched and arranged between the two-level signal protection circuits at the front end;

[0050] The large-capacity surge energy storage tank circuit is connected in series between the common-mode protection common end of the common-differential-mode power protection circuit composed of three-level varistors and the common-mode protection common end of the three-level signal protection circuit;

[0051] The collection end of the lightning surge monitoring circuit is respectively connected to the corresponding collection points on the power channel surge and interference protection circuit and the collection signal channel surge and interference protection circuit, and the output end of the lightning surge monitoring circuit is connected to the signal output end.

[0052] Through the combined protection and surge energy discharge, storage and absorption of the surge protection and interference protection circuit functions of the power supply channel surge and interference protection circuit and the acquisition signal channel surge and interference protection circuit, the common-mode and differential-mode surges and interference of the power supply interface and signal interface of the metering information acquisition equipment can be effectively protected and the surge energy can be discharged, stored and absorbed.

[0053] In the power channel surge and interference protection circuit, a common-mode / differential-mode surge protection circuit composed of three-level varistors is adopted to ensure the energy coordination between the third-level circuit, the second-level circuit and the first-level circuit of the power channel protection circuit, thereby effectively realizing the protection against surge interference of the power interface of the metering information acquisition equipment. Embodiment 2

[0054] The common differential mode power supply protection circuit composed of the three-level varistor includes a first-level power supply protection circuit, a second-level power supply protection circuit and a third-level power supply protection circuit;

[0055] The common differential mode anti-interference harmonic filter network circuit composed of two-stage inductance and capacitance includes a first-stage harmonic filter network circuit and a second-stage harmonic filter network circuit;

[0056] The power input terminal, the first-level power protection circuit, the first-level harmonic filter network circuit, the second-level power protection circuit, the second-level harmonic filter network circuit, the third-level power protection circuit, the power startup overcurrent buffer circuit and the power output terminal are connected in sequence;

[0057] A temperature protection circuit is connected in series in the first-level power protection circuit, and a power supply / deterioration indication circuit is also arranged on the first-level power protection circuit.

[0058] When the temperature of the varistor rises to the protection temperature due to the surge, the temperature protection circuit operates to cut off the faulty varistor channel to prevent the fault from further expanding. At the same time, the green LED of the power supply / deterioration indication circuit goes out, indicating that the circuit is faulty.

[0059] A common-mode and differential-mode anti-interference harmonic filter network circuit composed of two-stage inductors and capacitors is adopted. Through the cooperation of the first-stage harmonic filter circuit and the second-stage harmonic filter circuit, the strongest harmonic interference such as the 3rd, 5th, and 7th odd harmonics and the 2nd, 4th, and 6th even harmonics in the high-order harmonics on the power supply line are effectively filtered out, thereby improving the anti-interference ability of the power supply interface of the metering information acquisition equipment.

[0060] A power startup overcurrent buffer circuit is used. In order to avoid the surge current generated by the electronic equipment at the moment of startup, a power type NTC resistor is connected in series in the power channel to effectively suppress the surge current at startup. After the surge current suppression function is completed, the resistance value of the power type NTC resistor will drop to a very small level through the continuous action of its current. The power consumed can be ignored and will not affect the normal working current, achieving the effect of suppressing the surge when the power is turned on, and preventing the impact of the overcurrent at the moment of power startup on the metering information collection equipment. Embodiment 3

[0061] The three-level signal protection circuit includes a first-level signal protection circuit, a second-level signal protection circuit and a third-level signal protection circuit;

[0062] The signal input terminal, the first-level signal protection circuit, the surge energy coordination circuit, the second-level signal protection circuit, the third-level signal protection circuit and the signal output terminal are connected in sequence;

[0063] The first-level signal protection circuit is composed of a discharge tube to form a common mode and differential mode protection circuit; the second-level signal protection circuit is composed of a TVS tube to form a common mode and differential mode protection circuit; the third-level signal protection circuit is composed of a discharge tube to form a common mode and differential mode protection circuit;

[0064] A common-mode and differential-mode signal protection circuit consisting of two-stage discharge tubes is used, one stage is set at the input end, and the other stage is set at the output end. The input end protection circuit consists of a three-pole gas discharge tube and a two-pole gas discharge tube, which realizes the common-mode and differential-mode surge protection of the input end of the signal channel. The output end protection circuit consists of a three-pole gas discharge tube or a three-pole gas discharge tube and a two-pole gas discharge tube, which realizes the reverse common-mode and differential-mode protection of the overvoltage impact of the circuit itself from the surge at the output end of the signal channel, thereby improving the working reliability and service life of the protection circuit. In the acquisition signal channel surge and interference protection circuit, a common-mode and differential-mode protection circuit composed of a second-stage TVS tube is also used.

[0065] A surge energy coordination circuit is connected in series between the first-stage discharge tube protection circuit of the input signal and the second-stage TVS tube protection circuit of the signal. The circuit uses a power winding resistor element to coordinate the lightning surge energy between the input discharge tube protection circuit and the TVS tube protection circuit. When a surge overvoltage is introduced, the TVS tube protection circuit starts first because the TVS tube has a fast response time and the discharge tube starts slowly. Under the action of the surge current, a current voltage division is generated on the power winding resistor element, and this voltage is added to the clamping voltage after the TVS tube protection circuit is started. When the added voltage reaches the starting voltage of the input discharge tube protection circuit, the input discharge tube protection circuit starts quickly to discharge the lightning surge overvoltage in time. Embodiment 4

[0066] The large-capacity surge energy storage pool circuit includes two groups of surge energy storage pool circuits, one group of surge energy storage pool circuits is connected to the common mode protection common end of the power supply channel surge and interference protection circuit, and the other group of surge energy storage pool circuits is connected to the common mode protection common end of the acquisition signal channel surge and interference protection circuit. The common end of the two groups of surge energy storage pool circuits is connected in series to the virtual ground end.

[0067] The surge energy storage pool circuit uses two sets of large-capacity capacitor-resistor storage absorption circuits in series. Each set of storage absorption circuits consists of a large-capacity capacitor (2200uF / 400V) and a discharge resistor in parallel, and then an absorption protection diode is connected in reverse parallel with the capacitor. The positive pole of each storage absorption circuit is connected to the common end of the power channel surge and interference protection circuit and the acquisition signal channel surge and interference protection circuit respectively. The common end (negative pole) of the two storage absorption circuits in series is connected to the common virtual ground end. A surge discharge varistor is also connected in parallel between the positive poles of the two storage absorption circuits. When a common-mode lightning overvoltage surge or interference occurs, the large-capacity storage absorption circuit, the absorption protection diode, and the surge discharge varistor work together to achieve the effect of storing, suppressing discharge and absorbing surge energy or suppressing interference without the need for a ground wire. Embodiment 5

[0068] The lightning surge monitoring circuit is provided with a power supply circuit, a surge data acquisition circuit, a data processing and storage circuit, and a data transmission circuit;

[0069] The power supply circuit is connected to the power output terminal and supplies power to the surge data acquisition circuit, the data processing and storage circuit, and the data transmission circuit;

[0070] The surge data acquisition circuit acquires the status and surge data of the power supply channel and the signal channel, and is connected to the data processing and storage circuit;

[0071] The data processing and storage circuit processes and stores the collected power channel and signal channel states and surge data, and is connected to the data transmission circuit;

[0072] The data transmission circuit is connected to the signal output terminal;

[0073] The power supply circuit includes a micro AC-DC isolation module, the input end of the micro AC-DC isolation module is connected to the power output end, and the output end of the micro AC-DC isolation module supplies power to each module of the lightning surge monitoring circuit.

[0074] To prevent the impact of surge on the circuit, the power supply circuit takes power from the output interface of the surge and interference protection circuit of the power channel, and supplies power to the lightning surge monitoring circuit through a micro AC-DC isolation module. The surge data acquisition circuit acquires the surge data and temperature protection circuit status in the power channel, and acquires the TVS tube status and surge data in the signal channel; the power channel surge data and signal channel surge data are acquired by two current sensor coils, the current sensor coil of the power channel is connected to the differential mode surge protection varistor, and the current sensor coil of the signal channel is connected to one of the two signal lines; the power channel temperature protection circuit status acquisition is completed by connecting to the back end of the power supply / deterioration indication circuit after optical coupling isolation, and the TVS tube status acquisition of the signal channel is completed by the temperature fuse that is integrated with the TVS tube and isolated. When the temperature protection circuit status of the power channel changes, the optical coupling outputs a switch signal to the acquisition circuit. When the temperature fuse configured with the TVS tube of the signal channel changes its state, the temperature fuse changes from short circuit to open circuit, and outputs an open circuit signal to the acquisition circuit. The data processing and storage circuit processes and stores the collected power channel, signal channel status and surge data; uses high-speed operational amplifiers and A / D conversion circuits to send the collected power channel, signal channel status and surge data to the CPU, which processes and stores or displays them; it can be displayed by LED / digital tube, LCD screen, or not displayed but displayed by the management room. The data transmission circuit transmits the power channel, signal channel status and surge data; uses a dedicated RS-485 chip and connects to the back end of the signal channel line after optical coupling isolation, sets the appropriate communication address and related parameters, and transmits data with the power management room to achieve remote monitoring of lightning surges, reduce maintenance costs, and provide data support for later lightning disaster analysis. Embodiment 6

[0075] Based on the technical solutions of Embodiments 1 to 5, in practical applications, Figure 2 The circuit shown is composed of:

[0076] The common differential mode power supply protection circuit composed of the three-level varistor includes a first-level power supply protection circuit, a second-level power supply protection circuit and a third-level power supply protection circuit;

[0077] The first-level protection circuit of the power supply includes varistor 1 M1, varistor 2 M2, varistor 3 M3, varistor 4 M4, varistor 5 M5, varistor 6 M6, temperature fuse 1 T1, and temperature fuse 2 T2. Among them, varistor 1 and varistor 3, varistor 2 and varistor 4, temperature fuse 1 and varistor 6, varistor 5 and temperature fuse 2 are connected in series with each other, and are simultaneously connected to the two ports of the power input end, and are simultaneously connected to the two ports of the input end of the anti-interference harmonic filter network circuit of the front end. The middle lead of the series connection of varistor 1 and varistor 3 and varistor 2 and varistor 4 is connected to the common end of the common mode protection of the three-level power supply protection circuit;

[0078] The second-level protection circuit of the power supply includes a varistor seven M7, a varistor eight M8, and a varistor nine M9, wherein the varistor seven and the varistor eight are connected in series with each other and connected to the two ports of the output end of the anti-interference harmonic filter network circuit at the front end, and are connected to the two ports of the input end of the anti-interference harmonic filter network circuit at the back end, and the two ends of the varistor nine are connected to the two ports of the output end of the anti-interference harmonic filter network circuit at the front end, and are connected to the two ports of the input end of the anti-interference harmonic filter network circuit at the back end, and the middle lead of the series connection of the varistor seven and the varistor eight is connected to the common end of the common mode protection of the three-level power supply protection circuit;

[0079] The third-level protection circuit of the power supply includes a varistor ten M10, a varistor eleven M11, and a varistor twelve M12, wherein the varistor ten and the varistor eleven are connected in series with each other and connected to the two ports of the output end of the anti-interference harmonic filter network circuit at the front end, and are also connected to the power supply startup overcurrent buffer circuit, the two ends of the varistor twelve are connected to the two ports of the output end of the anti-interference harmonic filter network circuit at the front end, and are also connected to the power supply startup overcurrent buffer circuit, and the middle lead of the varistor ten and the varistor eleven connected in series is connected to the common mode protection common end of the three-level power supply protection circuit.

[0080] The common differential mode anti-interference harmonic filter network circuit composed of two-stage inductance and capacitance includes a first-stage harmonic filter network circuit and a second-stage harmonic filter network circuit;

[0081] The first-stage harmonic filter network circuit includes a common-mode filter coil L1, a common-mode capacitor C1, a common-mode capacitor C2, and a differential-mode capacitor C3. The common-mode capacitors L1 and C2 are connected in series with each other and connected to the output end of the common-mode filter coil L1. Both ends of the differential-mode capacitor L1 are connected to the output end of the common-mode filter coil L1. The input end of the common-mode filter coil L1 is connected to the input end of the power supply. The middle lead of the common-mode capacitor L1 and the common-mode capacitor L2 connected in series is connected to the common-mode protection common end of the three-stage power supply protection circuit.

[0082] The second-stage harmonic filter network circuit includes a common-mode filter coil 2 L2, a common-mode capacitor 3 C4, a common-mode capacitor 4 C5, and a differential-mode capacitor 2 C6. The common-mode capacitor 3 and the common-mode capacitor 4 are connected in series with each other and are connected to the output end of the common-mode filter coil 2. Both ends of the differential-mode capacitor 2 are connected to the output end of the common-mode filter coil 2. The input end of the common-mode filter coil 2 is connected to the output end of the common-mode filter coil 1. The middle lead of the common-mode capacitor 3 and the common-mode capacitor 4 connected in series is connected to the common-mode protection common end of the three-stage power supply protection circuit.

[0083] The power startup overcurrent buffer circuit is an NTC resistor, and the NTC resistor is connected in series between the third-level protection circuit of the power supply and the power output terminal.

[0084] The three-level signal protection circuit includes a first-level signal protection circuit, a second-level signal protection circuit and a third-level signal protection circuit.

[0085] The first-level signal protection circuit includes a gas discharge tube G1 and a gas discharge tube G2. The gas discharge tube G1 and the gas discharge tube G2 are connected in parallel to the signal input terminal. The gas discharge tube G1 is a three-level gas discharge tube, and the gas discharge tube G2 is a two-level gas discharge tube. The middle lead of the gas discharge tube G1 is connected to the common mode protection common terminal of the three-level signal protection circuit.

[0086] The second-level signal protection circuit includes a rectifier bridge circuit (D3-D6) composed of four fast diodes, as well as fast diode 1 D7, fast diode 2 D8, TVS transient diode D9, and temperature fuse T3. The input end of the rectifier bridge circuit (D3-D6) composed of four fast diodes is connected to the output end of the surge energy coordination circuit, and the two ends of its output end are respectively connected in series with fast diode 1 D7 and fast diode 2 D8, and then connected to the common end of the common mode protection of the three-level signal protection circuit. The TVS transient diode D9 is connected in series between the two ends of the output end of the rectifier bridge circuit (D3-D6) composed of four fast diodes. The temperature fuse T3 is set at the TVS transient diode D9 and connected to the collection end of the lightning surge monitoring circuit;

[0087] The third-level signal protection circuit is a gas discharge tube G3, which is a three-level gas discharge tube. Both ends of the gas discharge tube are respectively connected to the output end of the surge energy coordination circuit, and the middle lead of the gas discharge tube is connected to the common mode protection common end of the three-level signal protection circuit.

[0088] The surge energy coordination circuit comprises a power winding resistor R5 and a power winding resistor R6, wherein one end of the power winding resistor R5 is connected to one end of the signal input end, and the other end of the power winding resistor R6 is connected to one input end of a rectifier bridge circuit (D3-D6) formed by four fast diodes; one end of the power winding resistor R6 is connected to the other end of the signal input end, and the other end of the power winding resistor R6 is connected to the other input end of the rectifier bridge circuit (D3-D6) formed by four fast diodes;

[0089] The large-capacity surge energy storage tank circuit includes two groups of surge energy storage tank circuits with the same circuit structure. One group of surge energy storage tank circuits includes a rectifier diode D1, a common resistor R3, and an electrolytic capacitor C8. After the rectifier diode D1, the common resistor R3, and the electrolytic capacitor C8 are connected in parallel, one end thereof is connected to the common mode protection common end of the power supply channel surge and interference protection circuit; the other group of surge energy storage tank circuits includes a rectifier diode D2, a common resistor R4, and an electrolytic capacitor C9. After the rectifier diode D2, the common resistor R4, and the electrolytic capacitor C9 are connected in parallel, one end thereof is connected to the common mode protection common end of the acquisition signal channel surge and interference protection circuit, and the common end of the two surge energy storage tank circuits connected in series is connected to the virtual ground end;

[0090] The power supply / deterioration indication circuit includes a rectifier bridge DB1, a common resistor R1 and an LED lamp. The input end of the rectifier bridge DB1 is connected to the connection point between the temperature fuse 1 and the varistor 6, and the varistor 5 and the temperature fuse 2, and the output end of the rectifier bridge DB1 is connected in series with the common resistor R1 and then connected to the LED lamp;

[0091] The lightning surge monitoring circuit includes a power supply circuit, a surge data acquisition circuit, a data processing and storage circuit, and a data transmission circuit.

[0092] The power supply circuit includes a micro AC-DC isolated power supply module, a ±12V power boost and voltage regulator module, and a 3.3V voltage regulator. The input end of the micro AC-DC isolated power supply module is connected to the power output end, and the output end rectifies and steps down to output a 5V power supply. The ±12V power boost and voltage regulator module is connected to the output end of the micro AC-DC isolated power supply module and outputs a ±12V power supply for the acquisition module. The 3.3V voltage regulator is connected to the output end of the micro AC-DC isolated power supply module and outputs a 3.3V power supply for the data processing module and the data transmission module.

[0093] The surge data acquisition circuit includes a current sensor coil 1 L3, a current sensor coil 2 L4, an optocoupler isolation module, an operational comparator module circuit 1, and an operational comparator module circuit 2. The current sensor coil 1 L3 is arranged in the first-level protection circuit of the power supply, and a wire is connected in series between the varistor 4 and the varistor 6 of the first-level protection circuit of the power supply, and the wire passes through the current sensor coil 1 L3, and the two ends of the current sensor coil 1 L3 are connected to the input end of the operational comparator module circuit 1; the end of the power winding resistor 1 R5 passes through the current sensor coil 2 L4 through a wire and is connected to an input end of the rectifier bridge circuit (D3-D6), and the two ends of the current sensor coil 2 L4 are connected to the input end of the operational comparator module circuit 2, and the input end of the optocoupler isolation module is connected to the two ends of the LED lamp, and at the same time, an electrolytic capacitor C7 is connected in parallel to the two ends of the input end of the optocoupler isolation module, and a common resistor R2 is connected in series;

[0094] The output end of the operational comparator module circuit 1, the output end of the operational comparator module circuit 2 and the output end of the optical coupling isolation module are respectively connected to the input end of the data processing and storage circuit;

[0095] The operational comparator module circuit 1 and the operational comparator module circuit 2 are designed with the same circuit structure, and the connection mode of the components is the acquisition end, the precision operational amplifier, the high-speed operational amplifier, the voltage comparator, the voltage follower, and the input end of the data processing and storage circuit in sequence;

[0096] The data processing and storage circuit includes a data processing chip and a display screen. The input end of the data processing chip is connected to the output end of each acquisition module, and the display screen is connected to the signal end of the data processing module.

[0097] The data transmission circuit is a 485 communication module with optical coupler isolation. The input end of the 485 communication module with optical coupler isolation is connected to the signal output end of the data processing chip, and the output end of the 485 communication module with optical coupler isolation is connected to the signal output end.

[0098] Through the technical solution of this application, the combination of the power channel surge and interference protection circuit, the acquisition signal channel surge and interference protection circuit, the large-capacity surge energy storage pool circuit and the lightning surge monitoring circuit functions completes surge interference protection and surge energy discharge, storage and absorption, and realizes effective protection and surge energy discharge, storage and absorption of the common-mode and differential-mode surges and interference of the power interface and signal interface of the metering information acquisition equipment. And through the lightning surge monitoring circuit, the use status and surge data of the surge protection and anti-interference protector are collected, processed, stored and transmitted, realizing remote monitoring of lightning surges, reducing maintenance costs, and providing data support for later lightning disaster analysis. It is realized that the surge protection and anti-interference protector does not need to be connected to the lightning protection grounding network that meets the grounding resistance requirements with a grounding wire to reliably protect against interference from lightning-induced surges and discharge, store and absorb surge energy. It effectively solves the problems of the traditional surge protection mode of the existing power substation metering information collection system, such as poor surge protection effect and poor anti-interference ability; leakage current to the ground; small lightning impulse current capacity; high lightning impulse residual pressure; small power and signal common mode surge absorption capacitor capacity, limited surge absorption energy; plastic shell with no protection effect on interference signals; no lightning surge monitoring function, unable to understand the use status of the lightning arrester in the power management room, and implement remote monitoring. It can effectively prevent the damage to the metering information collection equipment caused by instantaneous common mode, differential mode overvoltage and overcurrent and interference caused by lightning induced surge overvoltage, operation overvoltage, lightning induced capacitive coupling, lightning induced inductive coupling, and high-order harmonic interference caused by the startup of large current power loads. The lightning induced surge protection capability of the utility model product enables the power interface of the metering information acquisition equipment to withstand a lightning induced surge overcurrent impact of up to 30000A@8 / 20μs, and the impact residual voltage is as low as 1.0kV; the signal interface can withstand a lightning induced surge overvoltage impact of up to 15000V@1.2 / 50μs, and the impact residual voltage is as low as 30V; the power interface can protect the strongest harmonic interference such as the 3rd, 5th, and 7th odd harmonics and the 2nd, 4th, and 6th even harmonics in the high-order harmonics on the power supply line; there is no ground leakage current; the power supply and signal common mode surge absorption capacitor has a large capacity (2200uF / 400V), and the surge absorption energy is large. It greatly improves the lightning induced surge resistance and anti-interference ability of the metering information acquisition equipment, reduces the damage rate of the metering information acquisition equipment, reduces the operation and maintenance costs of the power supply management unit, and produces good social and economic benefits. It has the advantages of simple structure, reliable performance, remote monitoring, convenient maintenance, and good lightning induced surge protection and anti-interference effects.

[0099] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

[0100] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A groundless surge and interference protection device for a power station area metering information collection system, characterized in that: Including power channel surge and interference protection circuit, acquisition signal channel surge and interference protection circuit, large-capacity surge energy storage pool circuit, lightning surge monitoring circuit, The power channel surge and interference protection circuit is provided with a power input terminal for connecting to a power source and a power output terminal connected to an information collector device; The acquisition signal channel surge and interference protection circuit is provided with a signal input terminal for connecting to a signal and a signal output terminal connected to an information collector device; The power channel surge and interference protection circuit includes a common differential mode power protection circuit composed of a three-stage varistor arranged between the power input terminal and the power output terminal, a common differential mode anti-interference harmonic filter network circuit composed of a two-stage inductor and capacitor, and a power startup overcurrent buffer circuit; Two anti-interference harmonic filter network circuits are respectively matched and arranged between two adjacent power protection circuits, and an overcurrent buffer circuit is arranged between the power protection circuit at the end and the power output terminal; The acquisition signal channel surge and interference protection circuit includes a three-level signal protection circuit and a surge energy matching circuit arranged between the signal input end and the signal output end, and the surge energy matching circuit is matched and arranged between the two-level signal protection circuits at the front end; The large-capacity surge energy storage tank circuit is connected in series between the common-mode protection common end of the common-differential-mode power protection circuit composed of three-level varistors and the common-mode protection common end of the three-level signal protection circuit; The collection end of the lightning surge monitoring circuit is respectively connected to the corresponding collection points on the power channel surge and interference protection circuit and the collection signal channel surge and interference protection circuit, and the output end of the lightning surge monitoring circuit is connected to the signal output end.

2. According to claim 1, a groundless surge protection device for a power substation metering information collection system, characterized in that: The common differential mode power supply protection circuit composed of three-level varistors includes a first-level power supply protection circuit, a second-level power supply protection circuit and a third-level power supply protection circuit. The common differential mode anti-interference harmonic filter network circuit composed of two-stage inductance and capacitance includes a first-stage harmonic filter network circuit and a second-stage harmonic filter network circuit. The power input terminal, the first-level power protection circuit, the first-level harmonic filter network circuit, the second-level power protection circuit, the second-level harmonic filter network circuit, the third-level power protection circuit, the power startup overcurrent buffer circuit and the power output terminal are connected in sequence.

3. According to claim 2, a groundless surge protection device for an electric power area metering information collection system is characterized in that: A temperature protection circuit is connected in series in the first-level protection circuit of the power supply.

4. According to claim 1, a groundless surge protection device for a power substation metering information collection system, characterized in that: The three-level signal protection circuit includes a first-level signal protection circuit, a second-level signal protection circuit and a third-level signal protection circuit; The signal input terminal, the first-level signal protection circuit, the surge energy coordination circuit, the second-level signal protection circuit, the third-level signal protection circuit and the signal output terminal are connected in sequence.

5. According to claim 4, a groundless surge protection device for a power substation metering information collection system, characterized in that: The first-level signal protection circuit is composed of discharge tubes to form common-mode and differential-mode protection circuits; the second-level signal protection circuit is composed of TVS tubes to form common-mode and differential-mode protection circuits; and the third-level signal protection circuit is composed of discharge tubes to form common-mode and differential-mode protection circuits.

6. According to claim 1, a groundless surge protection device for a power substation metering information collection system, characterized in that: The large-capacity surge energy storage pool circuit includes two groups of surge energy storage pool circuits, one group of surge energy storage pool circuits is connected to the common mode protection common end of the power supply channel surge and interference protection circuit, and the other group of surge energy storage pool circuits is connected to the common mode protection common end of the acquisition signal channel surge and interference protection circuit. The common end of the two groups of surge energy storage pool circuits is connected in series to the virtual ground end.

7. According to claim 1, a groundless surge protection device for an electric power area metering information collection system, characterized in that: The lightning surge monitoring circuit is provided with a power supply circuit, a surge data acquisition circuit, a data processing and storage circuit, and a data transmission circuit; The power supply circuit is connected to the power output terminal and supplies power to the surge data acquisition circuit, the data processing and storage circuit, and the data transmission circuit; The surge data acquisition circuit acquires the status and surge data of the power supply channel and the signal channel, and is connected to the data processing and storage circuit; The data processing and storage circuit processes and stores the collected power channel and signal channel states and surge data, and is connected to the data transmission circuit; The data transmission circuit is connected to the signal output terminal.

8. The groundless surge and interference protection device for the electric power area metering information collection system according to claim 7 is characterized in that: The power supply circuit includes a micro AC-DC isolation module, the input end of the micro AC-DC isolation module is connected to the power output end, and the output end of the micro AC-DC isolation module supplies power to each module of the lightning surge monitoring circuit.

9. The groundless surge and interference protection device for the electric power substation area metering information collection system according to claim 2 or 3, characterized in that: The first-level power protection circuit is also provided with a power supply / deterioration indication circuit.

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