Surge protection device with temporary overvoltage protection function

Abstract

The utility model relates to the technical field of electrical protection devices, in particular to a surge protection device with a temporary overvoltage protection function, which comprises a piezoresistor assembly, an inductor and a switch assembly, the piezoresistor assembly is connected with the switch assembly in parallel, and two ends of the inductor are respectively connected with the piezoresistor assembly and the switch assembly. The switch assembly comprises a conduction switch, a combination switch, a resistor R1 and a capacitor, the conduction switch is in linkage connection with the combination switch, the conduction switch is connected with the capacitor in series, the resistor R1 is connected with the combination switch and the inductor in series, and one end, away from the conduction switch, of the capacitor is connected with the combination switch and the piezoresistor assembly; when the conduction switch is closed and the capacitor is fully charged, the combination switch is conducted. By means of the arrangement, the surge protection device can be prevented from being damaged by impact when overvoltage occurs; when surge voltage occurs, the surge protection device can effectively discharge the surge voltage, and the safety of electric equipment is protected.

Description

Technical Field

[0001] The utility model relates to the technical field of electrical protection devices, in particular to a surge protector with a temporary overvoltage protection function. Background Art

[0002] A surge protection device (SPD), also known as a lightning arrester, is an electronic device that provides safety protection for various electronic equipment, instruments, and communication lines. When a sudden spike in current or voltage is generated in an electrical circuit or communication line due to external interference, the surge protector can conduct and shunt the current in a very short time, thereby preventing the surge from damaging other equipment in the circuit. An SPD is an indispensable device for lightning protection of electronic equipment. Its function is to limit the instantaneous overvoltage that penetrates power lines and signal transmission lines to a voltage range that the equipment or system can withstand, or to discharge the powerful lightning current into the ground, protecting the protected equipment or system from impact.

[0003] Currently, traditional SPD devices can only protect against uS-level surge overvoltages. When a mS-level TOV (transient overvoltage) occurs in the line, the MOV inside the SPD is turned on for a long time due to the long-term overvoltage, generating high temperatures. When the temperature reaches a certain value, a short circuit occurs inside the MOV, causing a short-circuit failure in the power supply system.

[0004] It should be noted that the information disclosed in this background technology section is only intended to increase understanding of the overall background of the present invention, and should not be regarded as an admission or suggestion in any form that the information constitutes prior art already known to those skilled in the art. Utility Model Content

[0005] The utility model provides a surge protector with a temporary overvoltage protection function, which includes a varistor component, an inductor and a switch component. The varistor component and the switch component are connected in parallel, and the two ends of the inductor are respectively connected to the varistor component and the switch component. The switch component includes a conduction switch, a composite switch, a resistor R1 and a capacitor. The conduction switch is linked to the composite switch, the conduction switch and the capacitor are connected in series, the resistor R1 is connected in series with the composite switch and the inductor, and the end of the capacitor away from the conduction switch is connected to the composite switch and the varistor component; when the conduction switch is closed and the capacitor is fully charged, the composite switch is turned on.

[0006] Furthermore, the conduction switch is connected in series with a resistor R2, and the composite switch includes a control switch and a valve switch. The valve switch is connected in parallel with the conduction switch, and the control switch is connected to the valve switch and the conduction switch. The valve switch is connected in series with a resistor R1, one end of the control switch is respectively connected to the second end of the conduction switch and the positive electrode of the capacitor, and the negative electrode of the capacitor is connected to the positive electrode of the valve switch; the valve switch is connected in series with the control switch, and is turned on when the applied voltage of the conduction switch is greater than the preset voltage; the control switch is activated when the conduction switch is turned on.

[0007] Furthermore, the control switch is connected to the resistor R1, the first end of the conductive switch is connected in series to the second end of the resistor R2, the first end of the resistor R2 is connected to the first end of the resistor R1 and the first end of the inductor, the second end of the inductor is connected to the first end of the varistor assembly and the live wire, and the second end of the varistor assembly is connected to the capacitor and the neutral wire.

[0008] Furthermore, the control switch is one of a triode, an IGBT tube, a thyristor, a transistor, and an electronic relay.

[0009] Furthermore, when an overvoltage occurs, the conduction switch is turned on, which in turn causes the control switch to be turned on, and the overvoltage is charged to the capacitor via the inductor and resistor R1; when the voltage on the capacitor is greater than a preset voltage, the valve switch is turned on, and the valve switch discharges the overvoltage; when the overvoltage disappears, the conduction switch is turned off, and the valve switch is closed;

[0010] When a surge voltage occurs, the varistor component is turned on, the inductor generates inductive reactance to the high-frequency surge, and the capacitor absorbs the spike in the circuit, so that the conduction switch cannot be turned on and remains in the off state, and the surge voltage is discharged by the varistor component.

[0011] Furthermore, the control switch adopts a transistor, and the transistor is an NPN type.

[0012] Furthermore, the positive electrode of the valve switch is connected to the emitter of the transistor, and the negative electrode of the valve switch is connected to the collector of the transistor.

[0013] Furthermore, the varistor assembly also includes alloys connected in series.

[0014] Furthermore, the conduction switch is turned on before the control switch, and the control switch is turned on before the valve switch.

[0015] Furthermore, the valve switch is one of a diode, an IGBT tube, a thyristor, a transistor, and an electronic relay, and the conduction switch is one of a TVS tube, a varistor, a discharge tube, and a semiconductor discharge tube.

[0016] The utility model provides a surge protector with temporary overvoltage protection. When surge overvoltages are in the microsecond range, the inductor in the circuit will generate a large inductive reactance, preventing the surge from passing through. Consequently, the surge is discharged through the varistor (MOV) component. When an overvoltage (TOV) occurs, the inductor in the circuit is considered short-circuited because the TOV is a millisecond-level power frequency voltage. Furthermore, the conduction voltage of the varistor (MOV) component is higher than the conduction voltage of the switch G1. The TOV can be directly applied to the power resistor, preventing the MOV component from short-circuiting due to overvoltage. Consequently, the surge protector is protected from damage when an overvoltage (TOV) occurs. When a surge voltage occurs, the surge protector can effectively discharge the voltage, protecting the safety of electrical equipment.

[0017] Other features and beneficial effects of the present invention will be described in the following description, and some of the technical features and beneficial effects can be obviously derived from the description or understood by implementing the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, some of the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 This is a circuit diagram of a surge protector provided by an embodiment of the present invention;

[0020] Figure 2 yes Figure 1 The composite switch in FIG. 1 is a circuit diagram of a control switch and a valve switch. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments; the technical features designed in different implementation modes of the present invention described below can be combined with each other as long as they do not conflict with each other; based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] In the description of the present invention, it should be understood that the terms "center", "lateral", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In addition, the term "including" and any variation thereof all mean "at least including".

[0023] See also Figure 1 and Figure 2 , Figure 1 This is a circuit diagram of a surge protector provided by an embodiment of the present invention. Figure 2 yes Figure 1 The circuit diagram of the composite switch in FIG. 1 shows a control switch and a valve switch. To achieve at least one of the aforementioned advantages or other advantages, one embodiment of the present invention provides a surge protector. This surge protector has a temporary overvoltage protection function. As shown in the figure, the surge protector includes a varistor assembly MOV, an inductor L, and a switch assembly. The varistor assembly MOV is connected in parallel with the switch assembly, and the two ends of the inductor L are connected to the varistor assembly MOV and the switch assembly, respectively.

[0024] The switch assembly includes a conduction switch G1, a composite switch, a resistor R1, and a capacitor C. The conduction switch G1 is linked to the composite switch, which is connected in series with capacitor C. Resistor R1 is connected in series with the composite switch and inductor L. The negative terminal of capacitor C is connected to the composite switch and the varistor assembly MOV. When the conduction switch G1 is closed and capacitor C is fully charged, the composite switch is turned on.

[0025] Specifically, the conduction switch G1 is connected in series with a resistor R2, and the composite switch includes a control switch and a valve switch D1. The valve switch D1 is connected in parallel with the conduction switch G1, and the control switch connects the valve switch D1 and the conduction switch G1. The valve switch D1 is connected in series with a resistor R1, and one end of the control switch is respectively connected to the second end of the conduction switch G1 and the positive electrode of the capacitor C, and the negative electrode of the capacitor C is connected to the positive electrode of the valve switch D1; the valve switch D1 is connected in series with the control switch, and the control switch protects the valve switch; when the applied voltage to the conduction switch G1 is greater than a preset voltage, the conduction switch G1 is turned on, and the control switch is activated when the conduction switch G1 is turned on.

[0026] In this embodiment, the control switch can be a transistor Q1, but the present invention is not limited to this. In other embodiments, the control switch can also be an IGBT, a thyristor, a transistor, an electronic relay, or other devices. In this embodiment, the valve switch D1 is a diode, but the present invention is not limited to this. In other embodiments, the valve switch D1 can also be an IGBT, a thyristor, a transistor, an electronic relay, or other devices. It will only turn on when a preset voltage is reached. The conduction switch G1 includes a conduction switch G1 and a resistor R2 connected in series. The conduction switch G1 is connected in series with a capacitor C. The base of the transistor Q1 is connected to the second end of the conduction switch G1 and the positive terminal of the capacitor C, respectively. The negative terminal of the capacitor C is connected to the emitter of the transistor Q1. The valve switch D1 is connected in series with the collector and emitter of the transistor Q1. The inductor L, resistors R1, R2, valve switch D1, conduction switch G1, and capacitor C form a temporary overvoltage (TOV) discharge circuit. In some embodiments, the conduction switch G1 can be considered to be the conduction voltage of the varistor (MOV). In some embodiments, the conduction switch G1 may be one of a TVS tube, a varistor, a discharge tube, and a semiconductor discharge tube.

[0027] Furthermore, the control switch is connected to resistor R1, the first end of the conduction switch G1 is connected in series with the second end of resistor R2, the first end of resistor R2 is connected to the first end of resistor R1 and the first end of inductor L, the second end of inductor L is connected to the first end of the varistor assembly MOV and the live wire, and the second end of the varistor assembly MOV is connected to the capacitor C and the neutral wire. The positive electrode of the valve switch D1 is connected to the emitter of the transistor Q1, and the negative electrode of the valve switch D1 is connected to the collector of the transistor Q1. When the system voltage of the surge protector is normal, the system voltage is less than the conduction voltage of the conduction switch G1, so the transistor Q1 and valve switch D1 are turned off, and the TOV voltage discharge does not operate.

[0028] When an overvoltage (TOV) occurs, the TOV voltage is higher than the turn-on voltage of the conduction switch G1. The conduction switch G1 is turned on, transistor Q1 is turned on, and the overvoltage (TOV) charges capacitor C via inductor L and resistor R1. When the voltage on capacitor C exceeds a preset voltage, valve switch D1 is turned on, discharging the overvoltage (TOV) to prevent it from being applied to the varistor (MOV) and causing it to break down and short-circuit. When the overvoltage (TOV) disappears and the system voltage drops below the turn-on voltage of the conduction switch G1, the conduction switch G1 is turned off, and valve switch D1 is closed. Furthermore, the preset voltage can be 0.5V. Furthermore, resistor R1 is a high-power resistor.

[0029] When a surge voltage occurs, the conduction of the varistor component MOV limits the surge voltage, the inductor L generates inductive reactance to the high-frequency surge, and the capacitor C absorbs the spike in the circuit, making the conduction switch G1 unable to turn on and remain in the off state, so that the surge voltage is discharged by the varistor component MOV. At this time, the discharge circuit of the overvoltage TOV does not work.

[0030] The conduction switch G1 is turned on before the control switch, which in turn is turned on before the valve switch D1. That is, the control switch is turned on only when the temporary overvoltage TOV is greater than the conduction switch G1 condition, and only when the voltage across capacitor C rises to a preset voltage (e.g., approximately 2V).

[0031] This case utilizes an electronic switch to identify various types of overvoltage and then discharge the corresponding circuit. Because of this electronic switch, the switching process is free of sparks and arcs, which could potentially cause fires. Conversely, using mechanical switches to trip or automatically reclose the power supply could result in sparks and arcs, which could potentially cause fires.

[0032] In some embodiments, transistor Q1 is an NPN type. However, the present invention is not limited thereto. In other embodiments, transistor Q1 may also be a PNP type, and the circuit is adjusted accordingly.

[0033] In some embodiments, the varistor assembly MOV further includes an alloy connected in series.

[0034] In summary, the present invention provides a surge protector with temporary overvoltage protection. Because surge overvoltages are at the microsecond level, the inductor in the circuit will generate a large inductive reactance, preventing the surge from passing through, thereby discharging the voltage through the varistor (MOV) component. When an overvoltage (TOV) occurs, the inductor in the circuit is considered a short circuit because the TOV is at the millisecond level of power-frequency voltage. Furthermore, the turn-on voltage of the varistor (MOV) component is higher than the turn-on voltage of the switch G1. The TOV can be applied directly to the power resistor, preventing the MOV component from short-circuiting due to overvoltage. Consequently, the surge protector is protected from damage during a TOV event. When a surge voltage occurs, the surge protector effectively discharges the voltage, protecting electrical equipment.

[0035] In addition, those skilled in the art should understand that, although there are many problems in the prior art, each embodiment or technical solution of the present invention may be improved in only one or several aspects, without having to solve all the technical problems listed in the prior art or background art at the same time. Those skilled in the art should understand that the absence of any content in a claim should not be construed as a limitation on that claim.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A surge protector with temporary overvoltage protection function, characterized by: The surge protector comprises a varistor component, an inductor and a switch component, the varistor component and the switch component are connected in parallel, and two ends of the inductor are connected to the varistor component and the switch component respectively; The switch assembly includes a conduction switch, a composite switch, a resistor R1, and a capacitor. The conduction switch is linked to the composite switch, the conduction switch is connected in series with the capacitor, the resistor R1 is connected in series with the composite switch and the inductor, and the end of the capacitor away from the conduction switch is connected to the composite switch and the varistor assembly; when the conduction switch is closed and the capacitor is fully charged, the composite switch is turned on.

2. The surge protector with temporary overvoltage protection function according to claim 1, characterized in that: The conduction switch is connected in series with a resistor R2, and the composite switch includes a control switch and a valve switch. The valve switch is connected in parallel with the conduction switch, and the control switch connects the valve switch and the conduction switch. The valve switch is connected in series with a resistor R1, one end of the control switch is respectively connected to the second end of the conduction switch and the positive electrode of the capacitor, and the negative electrode of the capacitor is connected to the positive electrode of the valve switch; the valve switch is connected in series with the control switch, and is turned on when the applied voltage of the conduction switch is greater than the preset voltage; the control switch is activated when the conduction switch is turned on.

3. The surge protector with temporary overvoltage protection function according to claim 2, characterized in that: The control switch is connected to the resistor R1, the first end of the conductive switch is connected in series to the second end of the resistor R2, the first end of the resistor R2 is connected to the first end of the resistor R1 and the first end of the inductor, the second end of the inductor is connected to the first end of the varistor assembly and the live wire, and the second end of the varistor assembly is connected to the capacitor and the neutral wire.

4. The surge protector with temporary overvoltage protection function according to claim 2, characterized in that: The control switch is one of a triode, an IGBT tube, a thyristor, a transistor, and an electronic relay.

5. The surge protector with temporary overvoltage protection function according to claim 2, characterized in that: When an overvoltage occurs, the conduction switch is turned on, which in turn causes the control switch to be turned on, and the overvoltage charges the capacitor through the inductor and resistor R1; when the voltage on the capacitor is greater than a preset voltage, the valve switch is turned on, and the valve switch discharges the overvoltage; when the overvoltage disappears, the conduction switch is turned off, and the valve switch is closed; When a surge voltage occurs, the varistor component is turned on, the inductor generates inductive reactance to the high-frequency surge, and the capacitor absorbs the spike in the circuit, so that the conduction switch cannot be turned on and remains in the off state, and the surge voltage is discharged by the varistor component.

6. The surge protector with temporary overvoltage protection function according to claim 2, characterized in that: The control switch adopts a transistor, and the transistor is an NPN type.

7. The surge protector with temporary overvoltage protection function according to claim 6, characterized in that: The positive electrode of the valve switch is connected to the emitter of the transistor, and the negative electrode of the valve switch is connected to the collector of the transistor.

8. The surge protector with temporary overvoltage protection function according to claim 1, characterized in that: The varistor assembly also includes alloys connected in series.

9. The surge protector with temporary overvoltage protection function according to claim 2, characterized in that: The conduction switch is turned on before the control switch, and the control switch is turned on before the valve switch.

10. The surge protector with temporary overvoltage protection function according to claim 2, characterized in that: The valve switch is one of a diode, an IGBT tube, a thyristor, a transistor, and an electronic relay, and the conduction switch is one of a TVS tube, a varistor, a discharge tube, and a semiconductor discharge tube.

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