High-voltage-resistant low-trigger surge protection circuit and surge protector

Abstract

The application discloses a high-voltage-resistance low-trigger surge protection circuit and a surge protector, and relates to the technical field of surge protection circuits. The surge protection circuit comprises an input end, an output end, a protection main discharge module connected between the output end and the input end, a third-grade protection module connected to the input end, a second-grade protection module connected to the third-grade protection module, a first-grade protection module connected between the second-grade protection module and the output end, wherein the surge breakdown voltage of the second-grade protection module is the surge trigger voltage of the first-grade protection module, a shunt voltage-resistance module having one end connected to the input end and the other end connected to the output end, and a trigger module having one end connected to the input end and the other end connected between the second-grade protection module and the third-grade protection module. The second-grade protection module and the first-grade protection module are used to improve the power-frequency resistance voltage, and the surge breakdown voltage of the second-grade protection module is the surge trigger voltage of the first-grade protection module, so that the surge trigger voltage of the overall surge protection circuit is reduced through segmented triggering.

Description

Technical Field

[0001] The present invention relates to the technical field of surge protectors, and in particular to a high-voltage-withstand-low-trigger surge protection circuit and a surge protector. Background Art

[0002] A surge protector, also known as a lightning arrester, is an electronic device that provides safety protection for various surge protectors, instruments, and communication lines. When a sudden spike in current or voltage occurs in an electrical circuit or communication line due to external interference, the surge protector quickly conducts and diverts the current, preventing damage to other equipment in the circuit.

[0003] Lightning arresters mainly use a combination circuit of ceramic gas discharge tubes and varistors. In order to improve the power frequency withstand voltage and the insulation level of the equipment, traditional lightning arresters mainly use varistors and discharge tubes with higher discharge voltages. When the lightning impulse current flows through the varistors and discharge tubes with higher discharge voltages, the residual voltage of the lightning arrester will increase. When the residual voltage of the lightning arrester is too high, it will affect the normal operation of the equipment. To solve this problem, the traditional method is to use a lightning arrester with a large current capacity, good tolerance level, and high residual voltage for discharge at the front end, and a lightning arrester with a small current capacity, poor tolerance level, and low residual voltage at the back end. However, multiple lightning arresters need to be combined to achieve good results. And using multiple lightning arresters in combination will cause problems such as complex installation, high cost, and low efficiency. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a high-voltage, low-trigger surge protection circuit that can be triggered in stages to reduce the surge trigger voltage and improve the power frequency withstand voltage of the surge protection circuit. This circuit also requires fewer lightning arresters, saving costs.

[0005] The present invention application also discloses a surge protector.

[0006] In a first aspect, an embodiment of the present invention provides a high-voltage and low-trigger surge protection circuit, comprising:

[0007] Input terminal;

[0008] Output terminal;

[0009] A protective main leakage module, electrically connected between the output end and the input end;

[0010] The protection main leakage module includes:

[0011] A third-level protection module, electrically connected to the input end;

[0012] A second-level protection module, electrically connected to the third-level protection module;

[0013] A first-level protection module is electrically connected between the second-level protection module and the output end, and a surge breakdown voltage of the second-level protection module is a surge trigger voltage of the first-level protection module;

[0014] A shunt voltage-resistant module, one end of which is connected to the input end and the other end is connected to the output end, and the shunt voltage-resistant module is used to shunt when inputting a power frequency voltage to protect the protective main leakage module from flash collapse within the power frequency voltage range;

[0015] A trigger module has one end electrically connected to the input end and the other end connected between the second-level protection module and the third-level protection module.

[0016] The high-voltage-withstand and low-trigger surge protection circuit of the embodiment of the present invention has at least the following beneficial effects: when the input end is connected to the power frequency voltage, the second-level protection module and the first-level protection module are in a closed state, and the current is shunted through the shunt voltage-withstand module. When the connected voltage exceeds the power frequency voltage, the first-level protection module is turned on and then the second-level protection module is turned on. By setting the second-level protection module, the first-level protection module and the shunt voltage-withstand module, the power frequency withstand voltage of the surge protection circuit can be improved, and there is no need for multiple lightning arresters, which saves costs.

[0017] According to some other embodiments of the present invention, the high-voltage and low-trigger surge protection circuit, the shunt voltage module includes: a first resistor, a second resistor and a transient suppression diode;

[0018] One end of the transient suppression diode is connected between the second-stage protection module and the first-stage protection module, and the other end is connected to one end of the first resistor, and the other end of the first resistor is connected to the output end;

[0019] One end of the second resistor is connected between the input end and the transient suppression diode, and the other end is connected between the second-stage protection module and the input end.

[0020] According to some other embodiments of the high-voltage and low-trigger surge protection circuit of the present invention, the trigger module includes a trigger capacitor, one end of the trigger capacitor is connected to the input end and the other end is connected between the second resistor and the first-level protection module. When a surge occurs, the trigger capacitor outputs a trigger current to the first-level protection module.

[0021] According to some other embodiments of the high-voltage-withstand, low-trigger surge protection circuit of the present invention, one end of the first varistor is connected to the input end, and the other end is connected between the second resistor and the second-level protection module, and the first varistor is used to increase the power frequency voltage.

[0022] According to some other embodiments of the high-voltage-withstand-low-trigger surge protection circuit of the present invention, a plurality of the main protection leakage modules are provided, and the plurality of the main protection leakage modules are connected in parallel.

[0023] According to some other embodiments of the high-voltage-withstand-low-trigger surge protection circuit of the present invention, a protection module is provided between the protection main leakage modules, and the protection module is electrically connected between any two adjacent protection main leakage modules.

[0024] According to some other embodiments of the high withstand voltage and low trigger surge protection circuit of the present invention, the first-level protection module is a second discharge tube, and the second-level protection module is a first discharge tube.

[0025] In a second aspect, an embodiment of the present invention provides a surge protector comprising the high-voltage-withstand-low-trigger surge protection circuit as described in the first aspect.

[0026] The surge protector of the embodiment of the present invention has at least the following beneficial effects: by providing the high-voltage, low-trigger surge protection circuit of the first aspect, the power frequency withstand voltage of the high-voltage, low-trigger surge protection circuit can be improved.

[0027] Other features and advantages of the present application will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present application. The purposes and other advantages of the present application can be achieved and obtained through the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a module block diagram of a specific embodiment of a high-voltage, low-trigger surge protection circuit in an embodiment of the present invention;

[0029] Figure 2 This is a module block diagram of another specific embodiment of a high withstand voltage and low trigger surge protection circuit in an embodiment of the present invention;

[0030] Figure 3 This is a circuit schematic diagram of a specific embodiment of a high-voltage, low-trigger surge protection circuit in an embodiment of the present invention.

[0031] Reference numerals: 100, input end; 200, output end; 300, main leakage protection module; 310, first-level protection module; 320, second-level protection module; 330, shunt pressure-resistant module; 340, trigger module; 350, third-level protection module; 400, protection module. DETAILED DESCRIPTION

[0032] The concept and technical effects of the present application will be described clearly and completely in combination with the embodiments, so as to fully understand the purposes, features and effects of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments, and other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative labor are within the protection scope of the present application.

[0033] In the description of the present application, if the orientation description such as "upper", "lower", "front", "back", "left", "right" and the like is referred to, the orientation or position relationship indicated by the orientation or position relationship shown in the drawings is only for the convenience of describing the present application and simplifying the description, and is not intended to indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. If a feature is referred to as "provided", "fixed", "connected", "mounted" on another feature, it can be directly provided, fixed, connected or mounted on the other feature, or indirectly provided, fixed, connected or mounted on the other feature.

[0034] In the description of the embodiments of the present application, if "several" is referred to, it means more than one, if "multiple" is referred to, it means more than two, and if "greater than", "less than", "exceeding" is referred to, it should be understood as not including the number itself, if "and above", "and below", "and within" are referred to, it should be understood as including the number itself. If "first", "second" are referred to, it should be understood as being used to distinguish technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.

[0035] The surge protection circuit is also called a lightning protector to prevent the normal operation from being affected by the instantaneous high-voltage impact. Therefore, the general surge protector is generally provided with a surge protection circuit. However, the current surge protection circuit is single-section protection, and the voltage range is low. Therefore, the existing surge protection circuit cannot play a surge suppression role in a higher surge voltage range, thereby causing serious damage to the surge protector.

[0036] Based on this, the present application discloses a high-voltage low-trigger surge protection circuit and a surge protector. The high-voltage low-trigger surge protection circuit improves the power frequency withstand voltage range, and the segmented triggering reduces the surge trigger voltage. Therefore, only one surge protection circuit is needed to realize higher power frequency voltage resistance, and multiple lightning protectors are not needed, thereby saving costs.

[0037] In the first aspect, with reference to Figure 1The present invention discloses a high-voltage, low-trigger surge protection circuit, comprising an input terminal 100, an output terminal 200, and a main protection leakage module 300. The main protection leakage module 300 is connected between the input terminal 100 and the output terminal 200. The main protection leakage module 300 includes a first-stage protection module 310, a second-stage protection module 320, a shunt voltage module 330, a trigger module 340, and a third-stage protection module 350. The third-stage protection module 350 is electrically connected to the input terminal 100. One end of the second-stage protection module 320 is connected to the third-stage protection module 350, and the other end is connected to one end of the first-stage protection module 310. The other end of the first-stage protection module 310 is connected to the output terminal 200. One end of the shunt voltage module 330 is connected to the input terminal 100, and the other end is connected to the output terminal 200. The shunt voltage-resistant module 330 is used to perform shunt when the industrial frequency voltage is input, so that the second-level protection module 320 and the first-level protection module 310 are in a closed state, so that the surge protection circuit can instruct to perform a shunt, so that the surge protector connected with high withstand voltage and low trigger will not flash over within a certain industrial frequency voltage range. One end of the trigger module 340 is electrically connected to the input end 100, and the other end is connected between the third-level protection module 350 and the second-level protection module 320.

[0038] The input terminal 100 can be a live or neutral wire, the output terminal 200 is a ground wire, and the surge breakdown voltage of the second-stage protection module 320 is equal to the surge trigger voltage of the first-stage protection module 310. When the input surge voltage is greater than the surge breakdown voltage of the first-stage protection module 310, because the surge voltage rises faster than the power frequency voltage, the trigger module 340 generates a capacitive current and provides it to the first-stage protection module 310. When subjected to the surge voltage, the shunt voltage module 330 acts as a decoupling module, and the first-stage protection module 310 is triggered first. After the first-stage protection module 310 is turned on, the impedance of the first-stage protection module 310 decreases, and the voltage across the second-stage protection module 320 increases, thereby breaking down the second-stage protection module 320, causing the entire protection circuit to conduct and forming a discharge channel, thereby protecting the electrical equipment equipped with the surge protection device. Therefore, by triggering the first-stage protection module 310 and the second-stage protection module 320 in stages, the surge breakdown voltage of the entire circuit is reduced, thereby reducing the residual voltage of the surge protection circuit. The shunt and withstand voltage module 330 facilitates shunting during the voltage rise period. While the second-stage protection module 320 and the first-stage protection module 310 are in the off state, the electrical equipment equipped with the surge protection circuit can operate normally with the power frequency voltage. When a surge voltage is applied, the second-stage protection module 320 and the first-stage protection module 310 are in conduction, protecting the electrical equipment.

[0039] Specifically, the first-stage protection module 310 is the second gas discharge tube GDT2, and the second-stage protection module 320 is the first gas discharge tube GDT1. When the input terminal 100 is connected to a power frequency voltage, the first gas discharge tube GDT1 and the second gas discharge tube GDT2 cannot obtain sufficient conduction current in a certain voltage range, so that the first gas discharge tube GDT1 and the second gas discharge tube GDT2 are in an off state. When the input terminal 100 is connected to a surge voltage, the second gas discharge tube GDT2 is turned on, the impedance is reduced, and the voltage across the first gas discharge tube GDT1 is increased to form a conduction condition. Therefore, the first gas discharge tube GDT1 and the second gas discharge tube GDT2 are triggered in sections to reduce the surge breakdown voltage.

[0040] Referring to Figure 1 and Figure 3 In some embodiments, the shunt voltage-resistant module 330 includes a first resistor R1, a second resistor R2, and a transient suppression diode DW1. One end of the transient suppression diode DW1 is connected between the second-stage protection module 320 and the first-stage protection module 310, and the other end of the transient suppression diode DW1 is connected to one end of the first resistor R1. The other end of the first resistor R1 is connected to the output terminal 200. One end of the second resistor R2 is connected between the input terminal 100 and the transient suppression diode DW1, and the other end of the second resistor R2 is connected between the second-stage protection module 320 and the input terminal 100.

[0041] Specifically, one end of the transient suppression diode DW1 is connected between the first gas discharge tube GDT1 and the second gas discharge tube GDT2, the other end of the transient suppression diode DW1 is connected to one end of the first resistor R1, and the other end of the first resistor R1 is connected to the output terminal 200. One end of the second resistor R2 is connected to a live wire or a neutral wire, and the other end of the second resistor R2 is connected between the first gas discharge tube GDT1 and the live wire or between the first gas discharge tube GDT1 and the ground wire. When the power frequency voltage rises slowly, the decoupling effect of the first resistor R1 is not obvious, the transient suppression diode DW1 is broken down, and the current is output to the ground wire through the second resistor R2, the transient suppression diode DW1, and the first resistor R1. When a surge occurs in the live wire or the neutral wire, the voltage rises steeply, the transient suppression diode DW1 is decoupled due to the first resistor R1, and the response time is long, so that the second gas discharge tube GDT2 is turned on. After the second gas discharge tube GDT2 is turned on, the resistance value decreases, the voltage across the first gas discharge tube GDT1 rises to break down, and the entire discharge channel is formed, thereby forming a short circuit to prevent high voltage from damaging the electrical equipment. Moreover, the first gas discharge tube GDT1 is turned on only after the second gas discharge tube GDT2 is turned on, which realizes segmented conduction and improves the range of the withstand voltage to facilitate the configuration of high-voltage electrical equipment.

[0042] In some embodiments, the trigger module 340 includes: a trigger capacitor C1, one end of the trigger capacitor C1 is connected to the input terminal 100 and the other end is connected between the second resistor R2 and the first-level protection module 310. When a surge occurs, the trigger capacitor C1 outputs a trigger current to the first-level protection module 310.

[0043] Specifically, one end of the trigger capacitor C1 is connected to the live or neutral line, and the other end is connected to a second resistor R2 and a transient suppressor diode DW1. When a surge voltage is applied to the input terminal 100, and the surge voltage exceeds the trigger voltage of the first-stage protection module 310, the surge voltage rises faster than the power frequency power supply, causing the trigger capacitor C1 to generate a capacitive current that is supplied to the second discharge tube GDT2. The first resistor R1 acts as a decoupling device when the surge voltage is applied. The decoupling effect of the first resistor R1 increases the response time of the transient suppressor diode D1. At this time, the second discharge tube GDT2 is triggered first. After the second discharge tube GDT2 turns on, its impedance decreases, and the voltage across the first discharge tube GDT1 increases, creating a conduction condition and triggering the first discharge tube. The second discharge tube GDT2 and the first discharge tube GDT1 are triggered in stages, thereby reducing the surge breakdown voltage of the entire circuit module and the residual voltage of the protection circuit module. Therefore, providing the trigger capacitor C1 can promote the second discharge tube GDT2 to be turned on, so that the entire surge protection circuit is turned on at high voltage to protect the electrical equipment.

[0044] In some embodiments, the third-level protection module 350 includes: a first varistor MOV1, one end of the first varistor MOV1 is connected to the input terminal 100, and the other end is connected between the second resistor R2 and the second-level protection module 320. The first varistor MOV1 is used to improve the power frequency withstand voltage.

[0045] The first varistor MOV1 serves as the common-mode main leakage channel, disconnecting the freewheeling protection module 300. Therefore, when a surge occurs on the live or neutral line, the resistance across the first varistor MOV1 decreases sharply, and the voltage across the second discharge tube GDT2 rises until the second discharge tube GDT2 turns on, and then the voltage across the first discharge tube GDT1 rises. When the input voltage reaches the trigger voltage of the first discharge tube GDT1, the first discharge tube GDT1 turns on. The first discharge tube GDT1 breaks down, followed by the second discharge tube GDT2, thereby increasing the power frequency withstand voltage of the surge protection circuit. In this embodiment, by providing the first and second discharge tubes GDT1 and GDT2, the power frequency withstand voltage can be increased to within the range of 1700 to 2000V. The first varistor MOV1 also serves as a third level of protection for the entire surge protection circuit, further enhancing its protective effectiveness. When the input terminal 100 is connected to the power frequency voltage, the first varistor MOV1 is superimposed, and the withstand voltage level of the first varistor MOV1 is equal to the sum of the power frequency withstand voltages of each level of protection, so as to increase the power frequency voltage.

[0046] In some embodiments, a plurality of protective main leakage modules 300 are provided, corresponding to a plurality of input terminals 100. Each protective main leakage module 300 is connected to an input terminal 100 at one end and to an output terminal 200 at the other end. Specifically, each protective main leakage module 300 is connected to an input terminal 100 at one end and to a ground wire at the other end, thereby providing protection for the input terminals 100 of different electrical devices.

[0047] By providing a plurality of protective main leakage modules 300 , the segmented triggered protection can be continuously extended to achieve multi-level protection.

[0048] Reference Figure 1 and Figure 2 In this embodiment, two protective main leakage modules 300 are provided, defined as a first protective main leakage module and a second protective main leakage module. The first protective main leakage module has one end connected to the live wire and the other to the ground wire; the second protective main leakage module has one end connected to the neutral wire and the other to the ground wire. By providing two protective main leakage modules 300, corresponding circuits can be protected.

[0049] In some embodiments, when several protective main leakage flow modules 300 are provided, a protective module 400 is electrically connected between two adjacent protective main leakage flow modules 300. The protective module 400 serves as a differential mode main leakage flow channel for the two adjacent protective main leakage flow modules 300 to prevent the direct formation of a loop when the two adjacent protective main leakage flow modules 300 are both turned on, thereby causing damage to the electrical equipment. Therefore, the provision of the protective module 400 can protect the electrical equipment adjacent to the protective main leakage flow module 300.

[0050] The protection module 400 is a second voltage-dependent resistor MOV2. The second voltage-dependent resistor MOV2 is arranged between two adjacent protection main discharge modules 300 to protect the input end 100 of the two adjacent protection main discharge modules 300. For example, the first protection main discharge module is connected to a live wire, and the second protection main discharge module is connected to a zero wire. The second voltage-dependent resistor MOV2 is arranged between the live wire and the zero wire to prevent short circuit of the live wire and the zero wire.

[0051] Reference will be made to the drawings Figures 1 to 3 A high-voltage surge protection circuit according to an embodiment of the present application is described in detail with reference to a specific embodiment. It should be understood that the following description is only exemplary and is not a specific limitation of the application.

[0052] When the voltage of the live wire or the zero wire rises slightly, the decoupling effect of the first resistor R1 is not obvious, the transient suppression diode DW1 is broken down, the current passes through the capacitive current of the trigger capacitor C1 and the first voltage-dependent resistor MOV1, and then passes through the second resistor R2, the transient suppression diode DW1, the first resistor R1, and is output to the ground wire to form a loop shunt, so that the circuit voltage is within a certain range and the main discharge channel cannot reach the breakdown current. When the voltage of the live wire or the zero wire rises to the surge voltage, the transient suppression diode DW1 is decoupled by the first resistor R1, and the response time is slow. The second discharge tube GDT2 is turned on because the capacitive current of the trigger capacitor C1 reaches the conduction condition. After the second discharge tube GDT2 is turned on, the resistance value decreases. The first voltage-dependent resistor MOV1 and the first discharge tube GDT1 are broken down to form the entire discharge channel.

[0053] In summary, the first discharge tube GDT1 and the second discharge tube GDT2 are arranged to realize segmented triggering, so as to reduce the triggering voltage and improve the power frequency withstand voltage range of the surge protection circuit, thereby facilitating protection configuration of some electrical equipment with high withstand voltage requirements.

[0054] In a second aspect, the embodiment of the present application further discloses a surge protector, which comprises the high-voltage surge protection circuit with low triggering according to the first aspect.

[0055] The specific circuit structure and circuit principle of the high-voltage surge protection circuit with low triggering are the same as those of the high-voltage surge protection circuit with low triggering according to the first aspect.

[0056] The embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited to the above-described embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the purpose of the present application. In addition, the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

Claims

1. A high-voltage, low-trigger surge protection circuit, characterized in that: include: Input terminal; Output terminal; A protective main leakage module, electrically connected between the output end and the input end; The protection main leakage module includes: A third-level protection module, electrically connected to the input end; A second-level protection module, electrically connected to the third-level protection module; A first-level protection module is electrically connected between the second-level protection module and the output end, and a surge breakdown voltage of the second-level protection module is a surge trigger voltage of the first-level protection module; A shunt voltage-resistant module, one end of which is connected to the input end and the other end is connected to the output end, and the shunt voltage-resistant module is used to shunt when inputting a power frequency voltage to protect the protective main leakage module from flash collapse within the power frequency voltage range; a trigger module, one end of which is electrically connected to the input end, and the other end of which is connected between the second-level protection module and the third-level protection module; The shunt voltage-resistant module includes: a first resistor, a second resistor and a transient suppression diode; One end of the transient suppression diode is connected between the second-stage protection module and the first-stage protection module, and the other end is connected to one end of the first resistor, and the other end of the first resistor is connected to the output end; One end of the second resistor is connected between the input end and the transient suppression diode, and the other end is connected between the second-stage protection module and the input end.

2. The high withstand voltage and low trigger surge protection circuit according to claim 1, characterized in that: The trigger module includes a trigger capacitor, one end of which is connected to the input end and the other end is connected between the second resistor and the first-level protection module. When a surge occurs, the trigger capacitor outputs a trigger current to the first-level protection module.

3. The high withstand voltage and low trigger surge protection circuit according to claim 2, characterized in that: The third-level protection module includes: a first varistor; One end of the first varistor is connected to the input end, and the other end is connected between the second resistor and the second-level protection module. The first varistor is used to increase the power frequency voltage.

4. The high withstand voltage and low trigger surge protection circuit according to any one of claims 1 to 3, characterized in that: A plurality of the main leakage protection modules are provided, and the plurality of the main leakage protection modules are connected in parallel.

5. The high withstand voltage and low trigger surge protection circuit according to claim 4, characterized in that: A protection module is provided between the protection main leakage flow modules, and the protection module is electrically connected between any two adjacent protection main leakage flow modules.

6. The high withstand voltage and low trigger surge protection circuit according to claim 1, characterized in that: The first-level protection module is a second discharge tube, and the second-level protection module is a first discharge tube.

7. A surge protector, characterized in that: The invention comprises a surge protection circuit with high withstand voltage and low triggering as claimed in any one of claims 1 to 6.

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