A circuit for reducing lightning surge current

Abstract

The present invention discloses a circuit for reducing lightning surge current, comprising a common mode filter module, a bridge rectifier DB1 connected to the common mode filter module, and a capacitor CE1, wherein the bridge rectifier DB1 is connected in parallel with the capacitor CE1 and then connected to a load, the common mode filter module comprises a common mode filter L1, and a coil arranged on the common mode filter, a varistor RV1 is connected between the common mode filter L1 and the alternating current, and the varistor RV1 is connected to the coil, and the present invention significantly reduces the lightning surge current of the entire circuit by adding a coil on the common mode filter and then connecting the varistor, and adding the coil and the varistor not only has low cost, but also effectively reduces the lightning surge current stress, avoids damage to the entire circuit, and increases the lightning surge resistance of electrical equipment.

Description

Technical Field

[0001] The invention relates to a circuit for reducing lightning surge current, and is applicable to the technical field of lightning circuits. Background Art

[0002] With the rise of various types of electrical equipment and the large-scale use of electricity, the switching transients and natural lightning transients of the power system at the AC input end will generate a strong interference voltage. If the front-stage surge lightning circuit is not properly protected, it will cause damage and failure of the electrical equipment. The corresponding lightning surge circuit is becoming more and more important. The existing lightning protection circuit often uses hard clamping to directly absorb the voltage of the lightning strike. The current stress that needs to be borne is very large, which is easy to cause damage to the lightning protection circuit. Summary of the invention

[0003] An object of the present invention is to provide a circuit for reducing lightning surge current.

[0004] The technical solution for achieving the purpose of the present invention is: a circuit for reducing lightning surge current, including a common-mode filtering module, a bridge rectifier DB1 connected to the common-mode filtering module, and a capacitor CE1, the bridge rectifier DB1 and the capacitor CE1 are connected in parallel and then connected to the load, the common-mode filtering module includes a common-mode filter L1, and a coil arranged on the common-mode filter, a varistor RV1 is connected between the common-mode filter L1 and the alternating current, and the varistor RV1 is connected to the coil.

[0005] Furthermore, one end of the varistor RV1 is connected between the common mode filter L1 and the live wire, and the other end of the varistor RV1 is connected to the coil and then connected to the neutral wire of the alternating current.

[0006] Furthermore, the common mode filter L1 is connected to the live wire of the alternating current, and the connection point between the common mode filter L1 and the bridge rectifier DB1 is connected to the varistor RV1 and the coil in sequence, and then connected to the neutral wire of the alternating current.

[0007] Furthermore, a resistor FR1 is included, one end of the resistor FR1 is connected to the live wire of the alternating current, and the other end of the resistor FR1 is connected to the common mode filter.

[0008] Furthermore, the varistor RV1 is a conventional varistor, model 14D471.

[0009] Furthermore, the model of the bridge rectifier DB1 is GBL410.

[0010] Furthermore, the common mode filter L1 is a UU10.5 magnetic core.

[0011] Compared with the prior art, the present invention has the following significant advantages: by adding a coil on the common mode filter and then connecting a varistor, the lightning surge current of the entire circuit is greatly reduced. Adding the coil and the varistor not only has low cost, but also effectively reduces the lightning surge current stress, avoids damage to the entire circuit, and increases the lightning surge resistance of electrical equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments of the present invention or the description of the prior art. Obviously, the drawings in the following description are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0013] Figure 1 is a schematic diagram of the circuit structure of embodiment 1 of the present invention;

[0014] Figure 2 It is a schematic diagram of the circuit structure of Example 2 of the present invention. DETAILED DESCRIPTION

[0015] Example 1

[0016] Combination Figure 1 A circuit for reducing lightning surge current includes a resistor FR1, a varistor RV1, a common-mode filter module, a bridge rectifier, and a capacitor CE1. The common-mode filter module includes a common-mode filter L1 and a coil arranged on the common-mode filter. One end of the resistor FR1 is connected to the live wire of the alternating current, the other end of the resistor FR1 is connected to the common-mode filter, and one end of the varistor RV1 is connected between the resistor FR1 and the common-mode filter. The other end of the varistor RV1 is connected to the 5th and 6th feet of the coil and then connected to the neutral line of the alternating current. The output end of the common-mode filter L1 is connected to the bridge rectifier and the capacitor CE1. The bridge rectifier and the capacitor CE1 are connected in parallel and then connected to the load. The varistor RV1 is a conventional varistor with a model of 14D471, the bridge rectifier DB1 has a model of GBL410, and the common-mode filter L1 is a UU10.5 magnetic core.

[0017] Example 2

[0018] Combination Figure 2A circuit for reducing lightning surge current includes a resistor FR1, a varistor RV1, a common-mode filter module, a bridge rectifier, and a capacitor CE1. The common-mode filter module includes a common-mode filter L1 and a coil arranged on the common-mode filter. One end of the resistor FR1 is connected to the live wire of the alternating current, and the other end of the resistor FR1 is connected to the common-mode filter. Pin 4 of the common-mode filter is connected to one end of the varistor RV1 and then connected to the bridge rectifier and the capacitor CE1. The bridge rectifier and the capacitor CE1 are connected in parallel and then connected to the load. The other end of the varistor RV1 is connected to pins 5 and 6 of the coil and then connected to the neutral wire of the alternating current. The varistor RV1 is a conventional varistor with a model of 14D471, the bridge rectifier DB1 has a model of GBL410, and the common-mode filter L1 is a UU10.5 magnetic core.

[0019] Working principle: when 220V is normally input between ACL and ACN, the varistor RV1 is not triggered, the 5th and 6th pins of the coil are vacant, and the current is directly loaded onto the common mode filter after passing through the resistor FR1. Then the current passes through the 1st and 4th pins of the common mode filter, and after being filtered by the bridge rectifier DB1 and the capacitor CE1, it provides power to the load RL1. After the load, it flows back from the 3rd pin to the 2nd pin, and the magnetic fields generated by the current cancel each other out.

[0020] When 2KV lightning is injected between ACL and ACN, the high voltage breaks down the varistor RV1, and a large amount of current will flow through pins 5 and 6 of the coil. The magnetic balance generated by the common-mode filter (common-mode inductor) is broken, and it becomes a differential-mode filter (common-mode inductor). At this time, the differential-mode filter will hinder the sudden current of lightning strikes and reduce the current passing through. Part of the current passes through pins 1 and 4 of the common-mode filter, the bridge rectifier, and capacitor CE1 for filtering to provide power to the load RL1, and then flows back from pin 3 to pin 2 after the load. The magnetic fields generated by the current cancel each other out. At this time, the current flowing through the test bridge rectifier DB1 is 68.8A (when the varistor RV1 and the coil are not set, the current flowing through the test bridge rectifier DB1 is 280A), and the surge current is significantly reduced.

[0021] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A circuit for reducing lightning surge current, comprising a common mode filter module, a bridge rectifier DB1 connected to the common mode filter module, and a capacitor CE1, wherein the bridge rectifier DB1 and the capacitor CE1 are connected in parallel and then connected to a load, characterized in that: The common mode filter module includes a common mode filter L1 and a coil arranged on the common mode filter, a varistor RV1 is connected between the common mode filter L1 and the alternating current, and the varistor RV1 is connected to the coil; One end of the varistor RV1 is connected between the common mode filter L1 and the live wire, and the other end of the varistor RV1 is connected to the coil and then connected to the neutral wire of the AC power; The common mode filter L1 is connected to the live wire of the AC power, and the connection point between the common mode filter L1 and the bridge rectifier DB1 is connected to the varistor RV1 and the coil in sequence, and then connected to the neutral wire of the AC power; It also includes a resistor FR1, one end of which is connected to the live wire of the alternating current, and the other end of the resistor FR1 is connected to the common mode filter.

2. A circuit for reducing lightning surge current according to claim 1, characterized in that: The varistor RV1 is a conventional varistor, model 14D471.

3. A circuit for reducing lightning surge current according to claim 1, characterized in that: The model of the bridge rectifier DB1 is GBL410.

4. A circuit for reducing lightning surge current according to claim 1, characterized in that: The common mode filter L1 is a UU10.5 magnetic core.

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