An electromagnetic protection device for 380V three-phase AC power line

Abstract

The utility model discloses an electromagnetic protection device for a 380V three-phase AC power line, which belongs to the technical field of electromagnetic protection, and includes an aluminum alloy protective shell; a PCB board is arranged in the aluminum alloy protective shell, and a 380V three-phase AC power line protection circuit is integrated on the PCB board, and the 380V three-phase AC power line protection circuit includes a 380V three-phase AC power supply, a first-level circuit, a second-level circuit and a third-level circuit; the 380V three-phase AC power supply is respectively connected to the first-level circuit, the second-level circuit and the third-level circuit. The utility model adopts a gas discharge tube limiting combined with a filter circuit to complete the protection against electromagnetic pulses. Through the combined use of a second-order discharge device and a filter circuit, the respective advantages can be brought into play when protecting the system from overvoltage events of different frequencies and energy levels, and the problem that the power supply system in the prior art cannot work normally due to interference from external electromagnetic pulses is solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of electromagnetic protection, and specifically relates to an electromagnetic protection device for a 380V three-phase AC power line. Background Art

[0002] As the heart of electronic equipment and the entire electrical system, the importance of the power supply system is self-evident. It is responsible for providing stable and reliable power to various circuits and components to ensure the normal operation and performance of the equipment. Once the power supply system fails or becomes unstable, it will not only cause the performance of the equipment to deteriorate, but may even cause the entire system to be paralyzed, causing serious economic losses and safety hazards. In practical applications, the power supply system must also have the ability to cope with various complex environments and working conditions to ensure that reliable power can be provided to the equipment under various conditions. However, with the increase in various electrical equipment and the widespread application of wireless communications, more complex power systems have also brought about more complex electromagnetic environments. Therefore, the electromagnetic protection of the power supply system plays a vital role in ensuring the normal operation of the equipment, improving production efficiency, and maintaining the overall stability of the system. Various electromagnetic pulses in the environment may enter the power supply system through transmission line coupling, backdoor coupling, etc., which will not only affect the normal operation of the power supply system, but may also cause electrical breakdown and melting damage to the components of the later stage of the circuit.

[0003] When designing electromagnetic radiation protection for circuits, we first need to have a deep understanding of the generation mechanism and propagation characteristics of electromagnetic radiation to ensure the pertinence and effectiveness of the design. When designing, we need to pay attention to the layout and wiring of the circuit, and try to avoid loops and long-distance transmission of high-frequency signals to reduce the radiation source. At the same time, we need to select appropriate shielding materials and methods to effectively shield key components and areas and block the propagation path of radiation. In addition, we need to pay attention to grounding and filtering design to ensure the stability and anti-interference ability of the circuit. Throughout the design process, we also need to consider factors such as cost, feasibility, and compatibility to achieve a balance between electromagnetic radiation protection and circuit performance. Utility Model Content

[0004] The purpose of the utility model is to provide an electromagnetic protection device for a 380V three-phase AC power line in view of the above-mentioned deficiencies in the prior art, so as to solve the problem that the existing power supply system cannot work normally due to interference from external electromagnetic pulses.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] An electromagnetic protection device for a 380V three-phase AC power line comprises an aluminum alloy protective shell; a PCB board is arranged in the aluminum alloy protective shell, a 380V three-phase AC power line protection circuit is integrated on the PCB board, and the 380V three-phase AC power line protection circuit comprises a 380V three-phase AC power supply, a first-level circuit, a second-level circuit and a third-level circuit; the 380V three-phase AC power supply is connected to the first-level circuit, the second-level circuit and the third-level circuit respectively.

[0007] Furthermore, the first stage circuit, the second stage circuit and the third stage circuit are arranged in parallel.

[0008] Further, the first stage circuit includes a first varistor, a second varistor, a third varistor, a fourth varistor, a fifth varistor, a sixth varistor, a first gas discharge tube, a second gas discharge tube and a third gas discharge tube;

[0009] The first varistor is connected to both ends of the U phase of the 380V three-phase AC power supply and the V phase of the 380V three-phase AC power supply; the fourth varistor is connected in series with the first gas discharge tube and connected to both ends of the U phase of the 380V three-phase AC power supply and the V phase of the 380V three-phase AC power supply;

[0010] The second varistor is connected to both ends of the 380V three-phase AC power supply V phase and the 380V three-phase AC power supply W phase; the fifth varistor is connected in series with the second gas discharge tube and then connected to both ends of the 380V three-phase AC power supply V phase and the 380V three-phase AC power supply W phase;

[0011] The third varistor is connected to both ends of the 380V three-phase AC power supply U phase and the 380V three-phase AC power supply W phase; the fourth varistor is connected in series with the third gas discharge tube and connected to both ends of the 380V three-phase AC power supply U phase and the 380V three-phase AC power supply W phase.

[0012] Further, the second stage circuit includes a first differential mode capacitor, a second differential mode capacitor, a third differential mode capacitor and a fourth differential mode capacitor, a first common mode capacitor, a second common mode capacitor, a third common mode capacitor, a fourth common mode capacitor and a common mode inductor;

[0013] The first differential mode capacitor is connected to both ends of the U phase of the 380V three-phase AC power supply and the V phase of the 380V three-phase AC power supply; the second differential mode capacitor and the third differential mode capacitor are connected in series and connected to both ends of the V phase of the 380V three-phase AC power supply and the W phase of the 380V three-phase AC power supply; the fourth differential mode capacitor is connected to both ends of the U phase of the 380V three-phase AC power supply and the W phase of the 380V three-phase AC power supply;

[0014] The first common-mode capacitor is connected to both ends of the U phase of the 380V three-phase AC power supply and the W phase of the 380V three-phase AC power supply; the second common-mode capacitor and the third common-mode capacitor are connected in series and connected to both ends of the V phase of the 380V three-phase AC power supply and the W phase of the 380V three-phase AC power supply; the fourth common-mode capacitor is connected to both ends of the U phase of the 380V three-phase AC power supply and the V phase of the 380V three-phase AC power supply;

[0015] The common mode inductors are connected to a 380V three-phase AC power supply U phase, a 380V three-phase AC power supply V phase and a 380V three-phase AC power supply W phase respectively.

[0016] Further, the third-level circuit includes a seventh varistor, an eighth varistor, a ninth varistor, a tenth varistor, an eleventh varistor, a twelfth varistor, a fourth gas discharge tube, a fifth gas discharge tube and a sixth gas discharge tube;

[0017] The seventh varistor is connected to both ends of the U phase of the 380V three-phase AC power supply and the V phase of the 380V three-phase AC power supply; the tenth varistor is connected in series with the fourth gas discharge tube and connected to both ends of the U phase of the 380V three-phase AC power supply and the V phase of the 380V three-phase AC power supply;

[0018] The eighth varistor is connected to both ends of the 380V three-phase AC power supply V phase and the 380V three-phase AC power supply W phase; the eleventh varistor is connected in series with the fifth gas discharge tube and then connected to both ends of the 380V three-phase AC power supply V phase and the 380V three-phase AC power supply W phase;

[0019] The ninth varistor is connected to both ends of the U phase of the 380V three-phase AC power supply and the W phase of the 380V three-phase AC power supply; the twelfth varistor is connected in series with the sixth gas discharge tube and connected to both ends of the U phase of the 380V three-phase AC power supply and the W phase of the 380V three-phase AC power supply.

[0020] The electromagnetic protection device for a 380V three-phase AC power line provided by the utility model has the following beneficial effects:

[0021] 1. The utility model adopts a gas discharge tube limiter combined with a filter circuit to complete the protection against electromagnetic pulses. By combining the second-order discharge device with the filter circuit, their respective advantages can be brought into play when protecting the system from overvoltage events of different frequencies and energy levels, solving the problem in the related technology that the power supply system cannot work normally due to interference from external electromagnetic pulses.

[0022] 2. The limiting part of the utility model uses a second-order gas discharge tube for limiting. The gas discharge tube is an electronic component that can generate a large current in the gas breakdown area by applying voltage to it. Its working principle is based on the phenomenon that when the gas breaks down, the gas molecules are ionized to cause the current to flow. The gas discharge tube is usually made of glass tube or ceramic tube, and is filled with certain inert gases (such as argon and neon, etc.) and a small amount of impurity gas. When the voltage at both ends of the gas discharge tube is higher than its protection specification value, a short circuit will occur inside it and absorb the input overvoltage. This characteristic enables the gas discharge tube to play a role in high-voltage protection at the input end of the equipment. Since the inter-electrode insulation resistance of the discharge tube is large and the parasitic capacitance is small, it has a clear advantage in lightning protection for high-frequency signal lines.

[0023] 3. The combined use of the front and rear secondary gas discharge tubes and the filter circuit of the utility model can reduce the burden of a single discharge tube while improving the discharge capacity, which helps to extend the service life of the protection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The utility model discloses a 380V three-phase AC power line protection circuit.

[0025] Figure 2 The schematic diagram of the circuit board structure of the 380V three-phase AC power line protection circuit is shown in the figure.

[0026] Among them, 1. 380V three-phase AC power supply U phase; 2. 380V three-phase AC power supply V phase; 3. 380V three-phase AC power supply W phase; 4. 380V three-phase AC power supply ground wire; 5. first varistor; 6. second varistor; 7. third varistor; 8. fourth varistor; 9. fifth varistor; 10. sixth varistor; 11. seventh varistor; 12. eighth varistor; 13. ninth varistor; 14. tenth varistor; 15. eleventh varistor Resistance; 16, twelfth varistor; 17, first gas discharge tube; 18, second gas discharge tube; 19, third gas discharge tube; 20, fourth gas discharge tube; 21, fifth gas discharge tube; 22, sixth gas discharge tube; 23, common mode inductor; 24, first differential mode capacitor; 25, second differential mode capacitor; 26, third differential mode capacitor; 27, fourth differential mode capacitor; 28, first common mode capacitor; 29, second common mode capacitor; 30, third common mode capacitor; 31, fourth common mode capacitor. DETAILED DESCRIPTION

[0027] The specific implementation methods of the utility model are described below to facilitate technical personnel in this technical field to understand the utility model, but it should be clear that the utility model is not limited to the scope of the specific implementation methods. For ordinary technical personnel in this technical field, as long as various changes are within the spirit and scope of the utility model defined and determined by the attached claims, these changes are obvious, and all utility model creations using the concept of the utility model are protected.

[0028] Example 1

[0029] This embodiment provides an electromagnetic protection device for a 380V three-phase AC power line. Figure 1 and Figure 2 , which specifically include:

[0030] An aluminum alloy protective shell is provided with a PCB board inside the aluminum alloy protective shell. A 380V three-phase AC power line protection circuit is integrated on the PCB board. The 380V three-phase AC power line protection circuit includes a 380V three-phase AC power supply, a first-level circuit, a second-level circuit and a third-level circuit. The 380V three-phase AC power supply is connected to the first-level circuit, the second-level circuit and the third-level circuit respectively.

[0031] The aluminum alloy protective shell of this embodiment is not shown in the drawings, and this embodiment does not protect or limit the specific shape of the aluminum alloy protective shell.

[0032] As a preferred embodiment of this embodiment, the first-stage circuit, the second-stage circuit and the third-stage circuit are arranged in parallel, and the first-stage circuit and the third-stage circuit are arranged at the front end of the 380V three-phase AC power line protection circuit, and the second-stage circuit is arranged at the rear end of the 380V three-phase AC power line protection circuit;

[0033] The 380V three-phase AC power supply also includes a 380V three-phase AC power supply ground wire 4 .

[0034] Specifically, the first-stage circuit is a first-stage discharge circuit of this embodiment, which is used to clamp the overvoltage generated by the electromagnetic pulse and discharge the current passing therethrough;

[0035] It includes a first varistor 5, a second varistor 6, a third varistor 7, a fourth varistor 8, a fifth varistor 9, a sixth varistor 10, a first gas discharge tube 17, a second gas discharge tube 18 and a third gas discharge tube 19;

[0036] The first varistor 5 is connected to both ends of the 380V three-phase AC power supply U phase 1 and the 380V three-phase AC power supply V phase 2; the fourth varistor 8 is connected in series with the first gas discharge tube 17 and then connected to both ends of the 380V three-phase AC power supply U phase 1 and the 380V three-phase AC power supply V phase 2;

[0037] The second varistor 6 is connected to both ends of the 380V three-phase AC power supply V phase 2 and the 380V three-phase AC power supply W phase 3; the fifth varistor 9 is connected in series with the second gas discharge tube 18 and then connected to both ends of the 380V three-phase AC power supply V phase 2 and the 380V three-phase AC power supply W phase 3;

[0038] The third varistor 7 is connected to both ends of the 380V three-phase AC power supply U phase 1 and the 380V three-phase AC power supply W phase 3; the fourth varistor 8 is connected in series with the third gas discharge tube 19 and then connected to both ends of the 380V three-phase AC power supply U phase 1 and the 380V three-phase AC power supply W phase 3.

[0039] The second stage circuit is a filter circuit of this embodiment, which is used to suppress the common-mode and differential-mode electromagnetic interference with smaller amplitudes on the power line and the wide-spectrum electromagnetic interference in the microwave frequency band.

[0040] It includes a first differential mode capacitor 24, a second differential mode capacitor 25, a third differential mode capacitor 26 and a fourth differential mode capacitor 27, a first common mode capacitor 28, a second common mode capacitor 29, a third common mode capacitor 30, a fourth common mode capacitor 31 and a common mode inductor 23;

[0041] The first differential mode capacitor 24 is connected to both ends of the 380V three-phase AC power supply U phase 1 and the 380V three-phase AC power supply V phase 2; the second differential mode capacitor 25 and the third differential mode capacitor 26 are connected in series to both ends of the 380V three-phase AC power supply V phase 2 and the 380V three-phase AC power supply W phase 3; the fourth differential mode capacitor 27 is connected to both ends of the 380V three-phase AC power supply U phase 1 and the 380V three-phase AC power supply W phase 3;

[0042] The first common-mode capacitor 28 is connected to both ends of the 380V three-phase AC power supply U phase 1 and the 380V three-phase AC power supply W phase 3; the second common-mode capacitor 29 and the third common-mode capacitor 30 are connected in series to both ends of the 380V three-phase AC power supply V phase 2 and the 380V three-phase AC power supply W phase 3; the fourth common-mode capacitor 31 is connected to both ends of the 380V three-phase AC power supply U phase 1 and the 380V three-phase AC power supply V phase 2;

[0043] The common mode inductor 23 is connected to the 380V three-phase AC power source U phase 1, the 380V three-phase AC power source V phase 2 and the 380V three-phase AC power source W respectively.

[0044] The third-stage circuit is a three-stage discharge circuit of the present embodiment, which is used to discharge the residual strong electromagnetic pulse energy again through the transient discharge tube.

[0045] It includes a seventh varistor 11, an eighth varistor 12, a ninth varistor 13, a tenth varistor 14, an eleventh varistor 15, a twelfth varistor 16, a fourth gas discharge tube 20, a fifth gas discharge tube 21 and a sixth gas discharge tube 22;

[0046] The seventh varistor 11 is connected to both ends of the 380V three-phase AC power supply U phase 1 and the 380V three-phase AC power supply V phase 2; the tenth varistor 14 is connected in series with the fourth gas discharge tube 20 and then connected to both ends of the 380V three-phase AC power supply U phase 1 and the 380V three-phase AC power supply V phase 2;

[0047] The eighth varistor 12 is connected to both ends of the 380V three-phase AC power supply V phase 2 and the 380V three-phase AC power supply W phase 3; the eleventh varistor 15 is connected in series with the fifth gas discharge tube 21 and then connected to both ends of the 380V three-phase AC power supply V phase 2 and the 380V three-phase AC power supply W phase 3;

[0048] The ninth varistor 13 is connected to both ends of the 380V three-phase AC power supply U phase 1 and the 380V three-phase AC power supply W phase 3; the twelfth varistor 16 is connected in series with the sixth gas discharge tube 22 and then connected to both ends of the 380V three-phase AC power supply U phase 1 and the 380V three-phase AC power supply W phase 3.

[0049] As a preferred embodiment of this embodiment, the 380V three-phase AC power line protection circuit has a rated voltage of 380V, a withstand voltage of 800V, a rated current of less than 20A, an operating frequency of 50Hz, and a common mode inductor 23 and a parallel bypass capacitor are used to construct a low-pass filter response. In the discharge network design, the gas discharge tube is used as a discharge to ensure that the voltage is clamped below 800V to meet the withstand voltage value. At the same time, LC filtering is used to obtain a low-pass filtering effect to ensure that the signal works normally while suppressing high-frequency pulses.

[0050] The protection component uses GDT as the primary and secondary discharge. The GDT uses 2RM800L-8 gas discharge tube to suppress narrow spectrum high voltage pulses. The maximum pulse breakdown voltage of the GDT reaches 1000V, which can effectively clamp.

[0051] The resistance values ​​of the first varistor 5 , the second varistor 6 , the third varistor 7 , the fourth varistor 8 , the fifth varistor 9 , the sixth varistor 10 , the seventh varistor 11 , the eighth varistor 12 , the ninth varistor 13 , the tenth varistor 14 , the eleventh varistor 15 , and the twelfth varistor 16 are preferably 911K.

[0052] The capacitance of the first differential mode capacitor 24, the second differential mode capacitor 25, the third differential mode capacitor 26, and the fourth differential mode capacitor 27 is 2.2uf.

[0053] The capacitance of the first common mode capacitor 28, the second common mode capacitor 29, the third common mode capacitor 30, and the fourth common mode capacitor 31 is 1uf;

[0054] The common mode inductor 23 is 0.75 / 1.15 mH.

[0055] During specific operation, the input pulse of this embodiment first causes the gas discharge tube to discharge. After the discharge pulse is filtered by the filter circuit, the high-frequency component in the wide-band electromagnetic pulse is suppressed. After the input pulse is protected by the protection component, the electromagnetic pulse is filtered and limited at the same time to achieve the protection effect on the subsequent circuit.

[0056] Although the specific implementation of the utility model is described in detail in conjunction with the drawings, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. An electromagnetic protection device for a 380V three-phase AC power line, characterized in that: It includes an aluminum alloy protective shell; a PCB board is arranged in the aluminum alloy protective shell, and a 380V three-phase AC power line protection circuit is integrated on the PCB board. The 380V three-phase AC power line protection circuit includes a 380V three-phase AC power supply, a first-level circuit, a second-level circuit and a third-level circuit; the 380V three-phase AC power supply is connected to the first-level circuit, the second-level circuit and the third-level circuit respectively.

2. The electromagnetic protection device for a 380V three-phase AC power line according to claim 1, characterized in that: The first-stage circuit, the second-stage circuit and the third-stage circuit are arranged in parallel.

3. The electromagnetic protection device for a 380V three-phase AC power line according to claim 1, characterized in that: The first stage circuit includes a first varistor, a second varistor, a third varistor, a fourth varistor, a fifth varistor, a sixth varistor, a first gas discharge tube, a second gas discharge tube and a third gas discharge tube; The first varistor is connected to both ends of the U phase of the 380V three-phase AC power supply and the V phase of the 380V three-phase AC power supply; the fourth varistor is connected in series with the first gas discharge tube and connected to both ends of the U phase of the 380V three-phase AC power supply and the V phase of the 380V three-phase AC power supply; The second varistor is connected to both ends of the V phase of the 380V three-phase AC power supply and the W phase of the 380V three-phase AC power supply; the fifth varistor is connected in series with the second gas discharge tube and connected to both ends of the V phase of the 380V three-phase AC power supply and the W phase of the 380V three-phase AC power supply; The third varistor is connected to both ends of the U phase of the 380V three-phase AC power supply and the W phase of the 380V three-phase AC power supply; the fourth varistor is connected in series with the third gas discharge tube and then connected to both ends of the U phase of the 380V three-phase AC power supply and the W phase of the 380V three-phase AC power supply.

4. The electromagnetic protection device for a 380V three-phase AC power line according to claim 1, characterized in that: The second stage circuit includes a first differential mode capacitor, a second differential mode capacitor, a third differential mode capacitor and a fourth differential mode capacitor, a first common mode capacitor, a second common mode capacitor, a third common mode capacitor, a fourth common mode capacitor and a common mode inductor; The first differential mode capacitor is connected to both ends of the U phase of the 380V three-phase AC power supply and the V phase of the 380V three-phase AC power supply; the second differential mode capacitor and the third differential mode capacitor are connected in series and connected to both ends of the V phase of the 380V three-phase AC power supply and the W phase of the 380V three-phase AC power supply; the fourth differential mode capacitor is connected to both ends of the U phase of the 380V three-phase AC power supply and the W phase of the 380V three-phase AC power supply; The first common-mode capacitor is connected to both ends of the U phase of the 380V three-phase AC power supply and the W phase of the 380V three-phase AC power supply; the second common-mode capacitor and the third common-mode capacitor are connected in series to both ends of the V phase of the 380V three-phase AC power supply and the W phase of the 380V three-phase AC power supply; the fourth common-mode capacitor is connected to both ends of the U phase of the 380V three-phase AC power supply and the V phase of the 380V three-phase AC power supply; The common mode inductor is connected to the 380V three-phase AC power supply U phase, the 380V three-phase AC power supply V phase and the 380V three-phase AC power supply W respectively.

5. The electromagnetic protection device for a 380V three-phase AC power line according to claim 1, characterized in that: The third-level circuit includes a seventh varistor, an eighth varistor, a ninth varistor, a tenth varistor, an eleventh varistor, a twelfth varistor, a fourth gas discharge tube, a fifth gas discharge tube and a sixth gas discharge tube; The seventh varistor is connected to both ends of the U phase of the 380V three-phase AC power supply and the V phase of the 380V three-phase AC power supply; the tenth varistor is connected in series with the fourth gas discharge tube and connected to both ends of the U phase of the 380V three-phase AC power supply and the V phase of the 380V three-phase AC power supply; The eighth varistor is connected to both ends of the 380V three-phase AC power supply V phase and the 380V three-phase AC power supply W phase; the eleventh varistor is connected in series with the fifth gas discharge tube and then connected to both ends of the 380V three-phase AC power supply V phase and the 380V three-phase AC power supply W phase; The ninth varistor is connected to both ends of the U phase of the 380V three-phase AC power supply and the W phase of the 380V three-phase AC power supply; the twelfth varistor is connected in series with the sixth gas discharge tube and connected to both ends of the U phase of the 380V three-phase AC power supply and the W phase of the 380V three-phase AC power supply.

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