Multi-stage collaborative surge protection circuit and protection method thereof

Abstract

The invention discloses a multi-stage collaborative surge protection circuit and a protection method thereof, and belongs to the technical field of circuit protection. The circuit comprises a differential mode-common mode MOV protection network, a surge depth discharge unit, an LC filtering delay module and a transient fine protection unit. The MOV network realizes preliminary interception of differential-mode and common-mode surges, the GDT and the current-limiting resistor deeply discharge residual high-energy surges, the LC module filters clutters and regulates and controls a response time sequence, and the TVSS inhibits residual transient overvoltage. According to the protection method, surge is coped with in a multi-stage cooperative mode according to the process of preliminary interception, deep discharge, fine suppression and cooperative reset. The invention solves the problems of single traditional protection level, non-cooperative differential mode and common mode protection and the like, adapts to complex surge scenes, improves the anti-surge reliability of the circuit, and can be used for power supply protection of equipment such as industrial control, communication base stations and the like.

Description

Technical Field

[0001] This invention belongs to the field of surge protector circuit protection technology, specifically a multi-level collaborative surge protection circuit and its application. Background Technology

[0002] In the operation of electronic power systems, surge overvoltages (such as lightning strikes and power grid fluctuations) are critical factors affecting equipment reliability and lifespan. Traditional surge protection solutions have significant drawbacks: The protection is limited in scope: most of them only focus on the protection of common mode overvoltage between "line and ground", and are insufficient in blocking differential mode overvoltage between "line and line". Differential mode overvoltage (such as voltage change between phase lines of the power grid) can easily directly damage precision power devices (such as IGBT modules).

[0003] Ignoring ground potential disturbances: Overvoltage discharge can easily cause a momentary rise in ground potential. Traditional solutions lack detailed cleaning of "residual transient overvoltage in the ground loop", which can lead to interference or even damage to voltage-sensitive analog circuits (such as sensors and signal conditioning modules).

[0004] Poor device synergy: Protection devices such as MOV (metal oxide varistor), GDT (gas discharge tube), and TVSS (transient voltage suppressor) are mostly simple parallel / series connections, failing to form a synergistic network of "graded energy discharge and precise timing coordination". When facing complex surges (such as mixed energy and superimposed fast and slow transient surges), problems such as single device overload failure and protection blind spots are likely to occur.

[0005] Therefore, there is an urgent need for a surge protection solution that covers multi-dimensional surges, strengthens ground loop protection, and optimizes device coordination to ensure the stable operation of electronic power systems in complex electromagnetic environments. Summary of the Invention

[0006] This invention aims to provide a multi-level collaborative surge protection circuit and its protection method, achieving dual-dimensional surge interception (differential mode + common mode), fine-grained ground loop protection, and energy classification and timing coordination of protection devices, thereby improving the circuit's protection capability and reliability against complex surges.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A multi-level coordinated surge protection circuit, characterized in that it includes: Differential-mode-common-mode MOV protection branch: includes a first MOV and a second MOV; the first MOV is connected in parallel between the first main line and the ground line, and the second MOV is connected in parallel between the second main line and the ground line, thus constructing a preliminary "line-to-ground" common-mode surge interception structure; Surge depth discharge unit: includes GDT and current limiting resistor; one end of the GDT is connected to the common node of the first main line and the first inductor, and the other end is connected to the first main line through the current limiting resistor; LC filter delay module: includes a first inductor, a second inductor, and a capacitor; the first inductor is connected in series with the first main circuit, the second inductor is connected in series with the second main circuit, and the capacitor is connected in parallel across the first inductor; Transient protection unit: includes a first TVSS and a second TVSS; the first TVSS is connected in parallel between the first main line and the ground line, and the second TVSS is connected in parallel between the second main line and the ground line.

[0008] The present invention further provides that the first MOV and the second MOV are used to intercept "line-to-ground" common mode overvoltage.

[0009] The present invention further includes a third MOV in the differential-common mode MOV protection branch extension; the third MOV is connected between the first main line and the second main line, and the third MOV is used to intercept line-to-line differential mode overvoltage; the transient protection unit also includes a third TVSS, which is connected in series between the first main line and the second main line.

[0010] The present invention further provides that the GDT is used to intercept high-energy surges that are not fully discharged by the MOV network, and the current-limiting resistor limits the conduction current of the GDT to avoid device overload.

[0011] The present invention further provides that the first inductor and the second inductor slow down the rise rate of the surge current, and together with the capacitor form an LC filter network to filter high-frequency noise from the surge and optimize the response timing of the protection device.

[0012] The present invention further provides that the first TVSS and the second TVSS suppress residual transient overvoltage of the main line, and the third TVSS strengthens the fine protection of the ground loop to counteract the ground potential disturbance caused by overvoltage discharge.

[0013] This invention also provides a multi-level collaborative surge protection method, characterized by comprising the following steps: Step 1: Preliminary interception of differential mode and common mode - Common mode surge triggers the first MOV and the second MOV to clamp and discharge, and differential mode surge triggers the third MOV to conduct and discharge, thus initially reducing the surge amplitude; Step 2: High-energy surge deep discharge - The residual high-energy surge triggers the GDT to break down and conduct, the current-limiting resistor limits the discharge current, and the GDT works in conjunction with the LC filter module to filter high-frequency noise and discharge the high-energy surge; Step 3: Fine transient suppression - The first TVSS and the second TVSS suppress residual transient overvoltages in the main line, and the extended third TVSS clears ground loop potential disturbances; Step 4: Device Co-reset - After the surge disappears, the MOV and GDT rely on their self-recovery characteristics, and the TVSS automatically returns to its initial state as the clamping voltage drops, and the circuit is ready for the next protection.

[0014] In a further embodiment of the present invention, in step 1, the third MOV prioritizes the response to line-to-line differential mode surges, fills the differential mode surge interception blind zone, and shortens the differential mode surge response time.

[0015] In a further embodiment of the present invention, in step 2, the GDT and the MOV protection branch form an "energy graded discharge" mechanism; the MOV prioritizes intercepting low- and medium-energy surges, while the GDT handles high-energy surges that the MOV has not processed, thus avoiding long-term overload of a single device.

[0016] The present invention further provides that the third TVSS is used to offset the abnormal rise in ground potential caused by surge discharge.

[0017] The beneficial effects of this invention are: Structural synergy: Through a multi-level structure of "MOV differential-common mode protection → GDT high-energy discharge → LC filter timing control → TVSS fine suppression", it covers the entire life cycle of surge protection and is suitable for complex power grid surge scenarios. Functional scalability: Supports MOV and TVSS network expansion, flexibly adapting to circuit requirements with different voltage levels and surge intensities.

[0018] The protection methods and circuit structure work together in a deep synergy, forming a closed-loop protection logic from surge interception, energy dissipation, residual suppression to device self-recovery, which significantly improves the circuit's surge resistance reliability and reduces the equipment damage rate. Attached Figure Description

[0019] Figure 1 This is the electrical schematic diagram of Embodiment 1 of the present invention.

[0020] Figure 2 This is the electrical schematic diagram of Embodiment 2 of the present invention.

[0021] Figure 3 This is a schematic diagram of the MOV structure used in Embodiments 1 and 2 of the present invention. Detailed Implementation

[0022] The embodiments of this application will be described in detail below, providing a clear and complete description of the technical solutions within this application. Obviously, the described embodiments are merely a portion of the embodiments of this application, and not all of them. The components of this application described and shown herein can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0023] Example 1

[0024] like Figure 1 As shown, the present invention provides a multi-level cooperative surge protection circuit, comprising: Differential-mode-common-mode MOV protection branch: includes a first MOV and a second MOV; the first MOV is connected in parallel between the first main line and the ground line, and the second MOV is connected in parallel between the second main line and the ground line, thus constructing a preliminary "line-to-ground" common-mode surge interception structure; Surge depth discharge unit: includes GDT and current limiting resistor; one end of the GDT is connected to the common node of the first main line and the first inductor, and the other end is connected to the first main line through the current limiting resistor; LC filter delay module: includes a first inductor, a second inductor, and a capacitor; the first inductor is connected in series with the first main circuit, the second inductor is connected in series with the second main circuit, and the capacitor is connected in parallel across the first inductor; Transient protection unit: includes a first TVSS and a second TVSS; the first TVSS is connected in parallel between the first main line and the ground line, and the second TVSS is connected in parallel between the second main line and the ground line.

[0025] The first and second MOVs are used to intercept line-to-ground common-mode overvoltage. The GDT (Gateway Filtering Device) is used to intercept high-energy surges that are not fully discharged by the MOV network. The current-limiting resistor limits the conduction current of the GDT to prevent device overload. The first and second inductors slow down the rise rate of the surge current and, together with the capacitor, form an LC filter network to filter high-frequency noise from the surge and optimize the response timing of the protection devices. The first and second TVSS (Transient Voltage Filtering System) suppress residual transient overvoltages in the main line. The entire circuit is housed in corresponding enclosures with an IP65 protection rating, effectively preventing dust and moisture intrusion and ensuring stable operation in harsh environments. The components are tightly connected via a PCB board, and the wiring design follows the low-impedance path principle, further improving circuit response speed and reliability. The overall structure is compact and easy to install, and it can be widely used in industrial automation, power systems, and communication equipment to provide comprehensive surge protection for critical equipment.

[0026] Example 2

[0027] like Figure 2 As shown, the present invention provides a multi-level cooperative surge protection circuit, comprising: Differential-mode-common-mode MOV protection branch: includes a first MOV and a second MOV; the first MOV is connected in parallel between the first main line and the ground line, and the second MOV is connected in parallel between the second main line and the ground line, thus constructing a preliminary "line-to-ground" common-mode surge interception structure; Surge depth discharge unit: includes GDT and current limiting resistor; one end of the GDT is connected to the common node of the first main line and the first inductor, and the other end is connected to the first main line through the current limiting resistor; LC filter delay module: includes a first inductor, a second inductor, and a capacitor; the first inductor is connected in series with the first main circuit, the second inductor is connected in series with the second main circuit, and the capacitor is connected in parallel across the first inductor; Transient protection unit: includes a first TVSS and a second TVSS; the first TVSS is connected in parallel between the first main line and the ground line, and the second TVSS is connected in parallel between the second main line and the ground line.

[0028] The first and second MOVs are used to intercept line-to-ground common-mode overvoltage. The GDT is used to intercept high-energy surges that are not fully discharged by the MOV network. The current-limiting resistor limits the conduction current of the GDT to prevent device overload. The first and second inductors slow down the rise rate of the surge current and, together with the capacitor, form an LC filter network to filter high-frequency noise from the surge and optimize the response timing of the protection device. The first and second TVSS suppress residual transient overvoltages in the main line.

[0029] The differential-mode-common-mode MOV protection branch extension also includes a third MOV; the third MOV is connected between the first main line and the second main line, and is used to intercept line-to-line differential-mode overvoltage; the transient protection unit also includes a third TVSS, which is connected in series between the first main line and the second main line, and the third TVSS strengthens the fine protection of the ground loop to offset the ground potential disturbance caused by overvoltage discharge. The GDT is used to intercept high-energy surges that are not fully discharged by the MOV network, and the current-limiting resistor limits the conduction current of the GDT to prevent device overload. The first inductor and the second inductor slow down the rise rate of the surge current, and together with the capacitor, form an LC filter network to filter high-frequency noise from the surge and optimize the response timing of the protection device. Example

[0030] This invention also provides a multi-level coordinated surge protection method, comprising the following steps: Step 1: Differential-common mode initial interception - Common mode surge triggers the first MOV and the second MOV to clamp and discharge, differential mode surge triggers the third MOV to conduct and discharge, initially reducing the surge amplitude; Step 2: High-energy surge deep discharge - The residual high-energy surge triggers the GDT to break down and conduct, the current-limiting resistor limits the discharge current, and the GDT works in conjunction with the LC filter module to filter high-frequency noise and discharge the high-energy surge; Step 3: Fine transient suppression - The first TVSS and the second TVSS suppress residual transient overvoltages in the main line, and the extended third TVSS clears ground loop potential disturbances; Step 4: Device Co-reset - After the surge disappears, the MOV and GDT rely on their self-recovery characteristics, and the TVSS automatically returns to its initial state as the clamping voltage drops, and the circuit is ready for the next protection.

[0031] In step 1, the third MOV prioritizes the response to line-to-line differential mode surges, filling the differential mode surge interception blind zone and shortening the differential mode surge response time.

[0032] The GDT and MOV protection branch form an "energy graded discharge" mechanism; the MOV prioritizes intercepting low- and medium-energy surges, while the GDT handles high-energy surges that the MOV does not process, thus avoiding long-term overload of a single device.

[0033] The third TVSS is used to offset the abnormal rise in ground potential caused by surge discharge.

[0034] This invention features excellent structural synergy: through a multi-level structure of "MOV differential-common mode protection → GDT high-energy discharge → LC filter timing control → TVSS fine suppression," it covers the entire lifecycle of surge protection and is adaptable to complex power grid surge scenarios. It also boasts functional scalability: supporting MOV and TVSS network expansion to flexibly adapt to circuit requirements with different voltage levels and surge intensities. The protection method and circuit structure are deeply synergistic, forming a closed-loop protection logic from surge interception, energy discharge, residual suppression to device self-recovery, significantly improving circuit surge resistance reliability and reducing equipment failure rates.

[0035] If certain terms are used in the specification and claims to refer to specific components, those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" as used throughout the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to." "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error.

[0036] It should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a product or system comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the product or system that includes that element.

[0037] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept by means of the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A multi-level cooperative surge protection circuit, characterized in that, include: Differential-mode-common-mode MOV protection branch: includes a first MOV and a second MOV; the first MOV is connected in parallel between the first main line and the ground line, and the second MOV is connected in parallel between the second main line and the ground line, thus constructing a preliminary "line-to-ground" common-mode surge interception structure; Surge depth discharge unit: includes GDT and current limiting resistor; one end of the GDT is connected to the common node of the first main line and the first inductor, and the other end is connected to the first main line through the current limiting resistor; LC filter delay module: includes a first inductor, a second inductor, and a capacitor; the first inductor is connected in series with the first main circuit, the second inductor is connected in series with the second main circuit, and the capacitor is connected in parallel across the first inductor; Transient protection unit: includes a first TVSS and a second TVSS; the first TVSS is connected in parallel between the first main line and the ground line, and the second TVSS is connected in parallel between the second main line and the ground line.

2. The multi-level cooperative surge protection circuit as described in claim 1, characterized in that, The first MOV and the second MOV are used to intercept "line-to-ground" common mode overvoltage.

3. The multi-level cooperative surge protection circuit as described in claim 2, characterized in that, The differential-common mode MOV protection branch extension also includes a third MOV; the third MOV is connected between the first main line and the second main line, and the third MOV is used to intercept "line-to-line" differential mode overvoltage; the transient protection unit also includes a third TVSS, which is connected in series between the first main line and the second main line.

4. The multi-level cooperative surge protection circuit as described in claim 3, characterized in that, The GDT is used to intercept high-energy surges that are not fully discharged by the MOV network, and the current-limiting resistor limits the conduction current of the GDT to prevent device overload.

5. A multi-level cooperative surge protection circuit as described in claim 4, characterized in that, The first inductor and the second inductor slow down the rise rate of the surge current, and together with the capacitor, they form an LC filter network to filter high-frequency noise from the surge and optimize the response timing of the protection device.

6. The multi-level cooperative surge protection circuit as described in claim 5, characterized in that: The first TVSS and the second TVSS suppress residual transient overvoltage in the main line, while the third TVSS strengthens the fine protection of the ground loop and counteracts the ground potential disturbance caused by overvoltage discharge.

7. A multi-level cooperative surge protection method based on the circuit described in any one of claims 3-6, characterized in that, The following steps are involved: Step 1: Preliminary interception of differential mode and common mode - Common mode surge triggers the first MOV and the second MOV to clamp and discharge, and differential mode surge triggers the third MOV to conduct and discharge, thus initially reducing the surge amplitude; Step 2: High-energy surge deep discharge - The residual high-energy surge triggers the GDT to break down and conduct, the current-limiting resistor limits the discharge current, and the GDT works in conjunction with the LC filter module to filter high-frequency noise and discharge the high-energy surge; Step 3: Fine transient suppression - The first TVSS and the second TVSS suppress residual transient overvoltages in the main line, and the extended third TVSS clears ground loop potential disturbances; Step 4: Device Co-reset - After the surge disappears, the MOV and GDT rely on their self-recovery characteristics, and the TVSS automatically returns to its initial state as the clamping voltage drops, and the circuit is ready for the next protection.

8. The multi-level coordinated surge protection method as described in claim 7, characterized in that, In step 1, the third MOV prioritizes the response to "line-to-line" differential mode surges, fills the differential mode surge interception blind zone, and shortens the differential mode surge response time.

9. The multi-level coordinated surge protection method as described in claim 7, characterized in that, In step 2, the GDT and MOV protection branch form an "energy graded discharge" mechanism; the MOV prioritizes intercepting low- and medium-energy surges, while the GDT handles high-energy surges that the MOV has not processed, thus avoiding long-term overload of a single device.

10. The multi-level coordinated surge protection method as described in claim 7, characterized in that, In step 3, the third TVSS is used to offset the abnormal rise in ground potential caused by surge discharge.

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