KR100767620B1 - Surge protective device for power supply line - Google Patents

Abstract

A lighting protecting apparatus for electric power is provided to offer services without being interrupted to a telecommunication field by including an electric leakage circuit breaker which is not tripped during an inflow of lighting. A lighting protecting apparatus for electric power includes a protecting module(100). The protecting module(100) is formed between two lines(L,n) selected on a polyphase electric power line and has a varistor device(Z1), a discharge-typed device(G1), and impedance(X1). The discharge-typed device(G1) is connected to the varistor device(Z1) in series. The impedance(X1) is connected to the discharge-typed device(G1) in parallel. The inner voltage of the varistor device(Z1) and the discharge start voltage of the discharge-typed device(G1) are lower than a maximum voltage value of common electric power voltage. The size of voltage distributed to the varistor device(Z1) and the discharge-typed device(G1) is controlled by the impedance(X1).

Description

Surge Protective Device for Power Supply Line

The present invention relates to a lightning protection device for a power supply having a precise protection capability capable of preventing the power supply from being interrupted by a transient characteristic due to surge inflow, which is not an earth leakage phenomenon, when the power supply is interrupted.

The present invention relates to a lightning protection device for a power line, and aims to reduce the lightning protection level as much as possible to prevent tripping of an earth leakage breaker while protecting the device to be protected more completely when a lightning strike flows. .

As a result of the lightning leakage tripping, the earth leakage breaker tripped the power line, as presented by domestic and overseas researchers at a seminar of the National Institute of Electrical and Electronics Engineers 2006.11. It is not a normal operation by the power supply, but the transient characteristics caused by the surge inflow or the operation of the surge protection device applied to the load caused a power failure (interruption) phenomenon has caused a serious problem in the high-tech information society.

It has been found that this is a proven error and malfunction of the earth leakage breaker itself, and the present invention provides a precise protection capability that can prevent the malfunction of the earth leakage breaker caused by the inflow of surge in order to prevent the above problems through lightning protection. The branch is to provide a lightning protection device for the power source.

1 is a conventional circuit breaker basic circuit, the peak value of the commercial power supply voltage 220V is 311V, the power supply method is 220V through three-phase 380V neutral well, the rate of accidental voltage rise in the case of one-phase ground, etc. Even if a varistor element having an operating voltage of 470V (DC, AC 330V) is inserted into the earth leakage breaker as the surge protection device between the AB point or the LN point, the varistor does not exceed the UL voltage. The clamping voltage characteristic of about 2 times of leaves a residual voltage of about 950V to 1,000V.

In addition, the surge protection device generally applied to the load circuit as shown in Figure 3 is composed of varistors (Za to Zc), has a withstand voltage of 430V to 470V and has a residual voltage characteristic of 850V to 1,000V.

In addition, a noise filter is applied to the load device, and two capacitors having a capacity of 0.02 uF are normally connected between the line and the ground. If there are 10 loads, the capacitor has a capacity of 0.4 uF. When a surge is introduced between the power line and the ground in addition to the element varistor, the surge protection device on the load side operates and a surge current is discharged between the line and the ground momentarily, and the earth leakage breaker determines that it is a short circuit and trips.

This operation is not a normal short circuit, but a very short instantaneous action between 1.2 kV and 50 kV, whereas the earth leakage breaker having a relatively slow operation speed of 30 ms has a problem of tripping after the surge potential has already disappeared.

In order to solve the above problems, the industry is trying to prevent tripping of the earth leakage circuit breaker by surge by applying a surge protection device such as a varistor in the earth leakage circuit breaker, but due to the high limiting voltage characteristics of the varistor device, The reality is that they do not have access to solutions.

In detail, the varistors xD431 (xD431 = 5D431 ~ 10D431) to xD471, which are widely used in the industry, have an actual limit voltage of about 900 V. Even if the varistor element is provided inside the ground fault circuit breaker, In the case of the varistor elements (xD431 to xD471) applied, the limit voltage is also about 900V, so that the circuit breaker trips due to the operation of the varistor of the load circuit regardless of the operation of the device in the circuit breaker.

That is, the conventional ground fault circuit breaker of FIG. 1 does not have a built-in protection device such as a varistor therein, and a ground fault circuit breaker that does not have a ground line even when one varistor element is mounted between the lines LN as shown in FIG. Compared to the configuration method and the device of the load facility as shown in FIG. 3, the capacity is not only small, the limit voltage itself is high, and there is no connection with the ground line, so that the protection element of the load circuit operates as the ground electrode. A trip of the earth leakage breaker occurs.

Therefore, even when the surge protection device is applied to the load circuit, the tripping of the earth leakage breaker cannot be prevented regardless of whether the protection device inside the earth leakage breaker is applied.

In this case, the use of a varistor element having a low limit voltage value causes deterioration of the element due to leakage current of the element, that is, thermal runaway phenomenon. Therefore, there is a limit that cannot be applied in the prior art based on the strict standard of UL1449.

An object of the present invention for solving the above problems is to improve the performance of the lightning protection device applied to the power line, while preventing the lightning strike, while maintaining the original function of the ground fault circuit breaker against the earth leakage, the number of times due to the inflow of lightning The present invention provides a lightning protection device for a power line and an earth leakage circuit breaker provided with the lightning protection device, which do not respond to a short circuit caused by a discharge phenomenon of a lightning protection device of a load circuit for several tens of kilowatts.

A detailed object of the present invention is to propose a lightning protection device having a clamping voltage that is much lower than a protection device applied inside a load circuit or a ground fault circuit breaker and applying it to a power line using the ground fault circuit breaker or the lightning protection device. By providing a circuit breaker as an integrated unit, it protects the device to be protected from lightning / surge, maintains the function of the circuit breaker, and prevents malfunction.

The lightning protection device of the power supply of the present invention is a lightning protection device for a power supply having a power supply line of a multiphase including a pair of power supply lines (L, n), the two lines selected from the power supply line of the multiphase multiline (L) and n) a protection module 100, wherein the protection module 100 includes a varistor element Z1, a discharge element G1 connected in series with the varistor element Z1, and the discharge element G1. And the impedance X1 connected in parallel with each other, wherein the withstand voltage of the varistor element Z1 and the discharge start voltage of the discharge type device G1 are lower than the maximum voltage value of the commercial power supply voltage. The magnitude of the voltage distributed to the varistor element Z1 and the discharge element G1 is controlled by X1).

In addition, a grounding wire is present in the power line of the multiphase polyline, and the protection module 100 is provided between all power lines constituting the power line of the multiphase polyline except for the grounding line, and each power line L, n and Varistor elements Z2 and Z3 are provided between the ground lines G.

In addition, the ground line is present in the power line of the multi-phase multi-wire, and the protection module 200 is provided in each power line constituting the power line of the multi-phase multi-line except for the ground line and the ground line.

In addition, a grounding wire is present on the power line of the multiphase polyline, and the protection module 200 is provided between a power line selected from the power line constituting the power line of the multiphase polyline except for the grounding line and the grounding line. A neutral line N is drawn out at the connection point of the varistor Z2 and the discharge type device G2 of 200, and the varistor element Z3 is provided between the neutral line N and the power line of each of the polyphase polywires. There is this.

Preferably, the impedance is a capacitor, a resistor, or a varistor element, and the varistor is a metal oxide varistor (MOV), and the discharge element is preferably a gas discharge tube (GDT). Do.

The lightning protection device of the power supply may be provided at the front end, the rear end, or the front end and the rear end of the earth leakage breaker 10 or the breaker, and the lightning protection device and the earth leakage breaker 10 or the breaker of the power supply are one case. It may be provided integrally within.

The lightning protection device of the power supply according to the present invention has excellent protection performance, which not only protects the device to be protected from lightning but also completely performs the original function of the existing earth leakage circuit. There is an effect to prevent the trip of the.

In this way, it protects the electric devices from lightning, and also realizes the normal protection function of the earth leakage breaker, and protects the lightning protection of the power line from tripping against lightning and surge inflow. By providing a circuit breaker that is not tripped, there is an advantage to provide an uninterrupted service in the telecommunication field.

Hereinafter, a lightning protection device of a power supply of the present invention will be described in detail with reference to the accompanying drawings. The drawings introduced below are provided by way of example so that the spirit of the invention to those skilled in the art can fully convey. Accordingly, the present invention is not limited to the drawings presented below and may be embodied in other forms. Also, like reference numerals denote like elements throughout the specification.

At this time, if there is no other definition in the technical terms and scientific terms used, it has a meaning commonly understood by those of ordinary skill in the art to which the present invention belongs, the gist of the present invention in the following description and the accompanying drawings Descriptions of well-known functions and configurations that may be unnecessarily blurred are omitted.

As shown in FIG. 4, the lightning protection device of the power supply of the present invention is a lightning protection device of a power supply which is connected to and operated with the power supply lines L and n, and the protection module 100 between the power supply lines L and n. The protection module 100 includes a varistor element Z1, a discharge element G1 connected in series with the varistor element Z1, and an impedance X1 connected in parallel with the discharge element G1. And the withstand voltage of the varistor element Z1 and the discharge start voltage of the discharge type element G1 are lower than the maximum voltage value of the commercial power supply voltage, and the varistor element Z1 is caused by the impedance X1. ) And the magnitude of the voltage distributed to the discharge type device G1.

The core idea of the present invention is to provide a residual voltage of at least about 600 V or less by using devices having a clamping voltage that is much lower than a surge protection device applied to a device inside a ground fault circuit breaker or a load circuit during a lightning strike. This protects the equipment using the power supply from lightning and also prevents the earth leakage breaker from tripping.

Based on FIG. 4 which is a basic embodiment of the lightning protection device (protection module 100) according to the present invention, the core idea of the present invention will be described in detail.

According to the idea of the present invention, the voltage limit of the varistor element Z1 constituting the protection module 100 should be significantly lower than the normal protection level. As a typical example, if the pair of (L, n) power lines are lines of an AC 220V line, the peak voltage of the AC 220V line is 311V, and the withstand voltage of a varistor element commonly used in the industry is 430V ( DC voltage limit of 470V (DC) and the manufacturer's standard voltage limit of these devices based on UL standard of these devices is 850V to 1,000V.However, in the environment where earth leakage breaker is installed and normal surge protector is installed in the load circuit It is known from the experimental results that the surge protection level for preventing the malfunction of the earth leakage breaker due to the inflow is about 600V or less.

Therefore, in order to satisfy this, the present invention cannot achieve the object of the present invention by using a varistor having a specification lower than 311 V, which is the peak value of the 220 V AC power supply voltage. In the embodiment of the present invention, a varistor having a rating of 220 V DC is used. By using, the maximum limiting voltage characteristic is about 450V (typically, varistor elements of UL standard products have a limiting voltage of 200% of the rated voltage), and the varistor element is used, which leads to the following technical problems. .

The use of a varistor element with a limiting voltage of 220 V means that a varistor element of 220 V DC is used even when referring to the UL standard. This means that the maximum voltage of AC 220 V is 311 V. At the moment of contact with the loud explosion sound and burnout problem, this is called thermal runaway phenomenon.

The above problem is required to meet the requirements of 1 mA or less, which is the leakage current allowance at the rated voltage indicated in the UL standard for the varistor element, and the commercial voltage to be applied in the present invention violates the standard as a varistor of DC 220V. It can only lead to thermal runaway.

In order to solve the above problem, the discharge type device G1 connected in series with the varistor element Z1 is introduced, and an impedance x1 connected in parallel with the discharge type device G1 is used. .

However, in the limiting voltage characteristic of the discharge type device, the limiting voltage characteristic is larger than that of the varistor, which is a residual voltage characteristic of about 1000 V or more, even if the rated voltage is 230 V, in series with the varistor. Even if the connection is made, a problem arises in that the limited voltage characteristic desired in the present invention cannot be obtained.

In the present invention, in order to solve this problem, the AC 220V commercial AC has a frequency characteristic of 50 ~ 60Hz and the center frequency of the brain / surge frequency spectrum is about 800KHz, the operating speed and varistor of the gas-filled discharge tube By adjusting the operating speed of the device and the difference in series impedance when the two devices are connected in series, thermal runaway is prevented and the limit voltage characteristic of 600V or less is obtained.

The discharge start voltage of the discharge type device G1 should be lower than the maximum voltage value of the commercial power supply voltage, and the maximum limit voltage characteristic should also be lower than 600 V, which is a target of the present invention. If the limit voltage of Z1 is about 450 V or less, and the limit voltage of the discharge type device G1 is 1000 V, the total limit voltage connected in series is 1450 V. Here, the planar impedance of the varistor element Z1 shown in the embodiment of FIG. 4 is very high at 3000 pF, and the gas-filled discharge tube has a very small characteristic of 1 pF.

In the embodiment of FIG. 4, the withstand voltage value of the varistor element Z1 is 220V (DC), and the discharge start voltage of the discharge type device G1 is DC 230V, which limits 220V from 311V, the maximum voltage value of the AC220V power line. The difference in voltage is shown. Based on the 430V level considering the voltage fluctuation rate and the margin, the discharge start voltage of 430V-220V = 210V will be provided to make stable operation characteristics for continuous use.

However, since the self-capacitance of the varistor element is 3000pF, since the discharge type device has an impedance of 1pF level, most voltages are divided by the discharge type device when the varistor device and the discharge type device are connected in series. Will occur again.

Due to this impedance difference, the discharge start voltage of the discharge type element should eventually be higher than 430V in the AC 220V line, and when combined with the maximum limit voltage of the varistor element, the limit voltage value within the target 600V cannot be obtained. do.

In order to solve the impedance difference between the varistor element and the discharge type device, the present invention has a feature of solving the discharge type device and the external impedance (x1) in parallel.

The impedance (x1) is similar to the impedance of the varistor element (Z1) and the discharge-type device (G1) so that the margin of voltage required for stable use of the conventional power supply to the varistor element (Z1) and the discharge-type device (G1) Since it serves to make the divided voltage, the impedance of the impedance (x1) is characterized by having an electric capacitance component of 0.1 times to about 2 times based on the internal capacitance that the varistor element Z1 normally has.

In addition, since the impedance (x1) may have a resistance component, the varistor element (Z1) having a rating of 220V DC has a resistance close to infinity until it reaches DC220V, but when the DC 220V reaches about 1mA It has a characteristic of operating as a resistor through which a current flows.

By utilizing the characteristic curvature of the device, a current of several tens of uA flows to obtain an appropriate voltage dividing value. Among the voltage dividing values obtained here, the voltage across the varistor has a constant voltage characteristic with little change even if the input voltage fluctuates. .

Based on this principle, the impedance (x1) is provided with a capacitor, a resistance element, or a small varistor having an appropriate capacitance, so that the divided portion of the impedance (x1) and the varistor (Z1) is connected across the discharge type device (G1) connected in series. When the voltage characteristics of the above-mentioned devices are divided by the same value as the value, AC220V, the peak value of 311V is the limit voltage value of 430V or more, presumed by dividing about 220V across the varistor and about 61V across the discharge element. It is possible to apply a discharge type device having a characteristic of 220V DC.

As a result, the idea that the discharge type device G1 connected in series with the varistor element Z1 can also be applied to an element having a limit voltage characteristic below the peak value of the power supply voltage.

Accordingly, the thermal runaway phenomenon of the varistor element Z1 having a low limit voltage can be prevented according to the partial pressure ratio due to the discharge voltage of the discharge type elements G1 connected in series. In the AC 220V power source, only 61V is divided for the discharge-type device, and in consideration of the voltage margin, it is possible to select a device having a discharge characteristic of about 220V. Thus, a varistor and 220V having a 220V DC characteristic on the AC220V power line can be selected. The technical idea of manufacturing a lightning protection device having a DC connection in series with the discharge type device has been completed.

In the limiting voltage characteristic at the time of lightning inflow, the varistor having the 220V DC characteristic has the limiting voltage characteristic of 450V DC level, but the discharge type device having the 220V DC characteristic has the 1000V level.

However, the lightning protection device of the present invention has a residual voltage characteristic according to voltage and time in the voltage / frequency characteristics of the discharge type element, and the above-described method is performed at an AC frequency of 60 Hz component due to the impedance (X1) connected in parallel. In the 800KHz component of the brain / surge frequency spectrum, the rising angle of the divided voltage and surge voltage is lowered due to the varistor (Z1) connected in series and the impedance (X1) connected in parallel. As the duration becomes longer instead of the rising voltage, the discharge is easily performed even at a low voltage, thereby obtaining stable voltage limit characteristics of 600 V or less.

Figure 5 is another embodiment of the lightning protection device of the present invention applied to a single-phase power line is provided with a basic protection module 100 for the power lines (L and n), respectively connected to the ground (G) line for the line The varistor element Z2 or Z3 is further provided.

Figure 6 is another embodiment of the lightning protection device of the present invention applied to a single-phase power line is provided with a basic protection module 100 for the power line (L and n), one power source selected from the power line (L and n) The protection module 200 is provided between the line L and the ground line G, and the neutral line N is drawn at the connection point between the varistor Z2 and the discharge type device G2 of the protection module 200, The varistor element Z3 is provided between the neutral line N and the other power supply line n. In addition, as shown in FIG. 7, the power supply line having the polyphase line may be applied similarly to FIG. 6.

4 to 7, the lightning protection device of the present invention described above is connected to the front end, the rear end, or the front end and the rear end of the conventional earth leakage breaker, respectively, to constitute a lightning protection type earth leakage breaker, or a similar electric circuit breaker (MCCB) and the like. There is a feature that can be combined to constitute a lightning protection circuit breaker.

Preferably, since the lightning protection device of the present invention can be manufactured and supplied integrally with the conventional earth leakage breaker 10 or the circuit breaker, the lightning protection device of the present invention may optionally include a conventional circuit breaker or earth leakage breaker. Can be manufactured in one case.

8A is an embodiment in which the lightning protection device 100 of the present invention is attached to the front of the conventional ground fault circuit breaker of FIG. 1, but the ground line G is not shown. Since the N terminal is grounded at the transformer side, the line n is the same concept as the ground line. When the surge protection circuit as shown in FIG. 2 is connected to the load circuit, if surge is introduced between the power line L and the ground G, before the surge protection element of the load circuit of FIG. As the surge protection device (Z1-G1) having the voltage characteristic operates, a discharge current flows between the line (L) and the ground (n). From the ground fault circuit breaker point, the current flows in the L-> L direction. The earth leakage breaker is not tripped because it is recognized.

8B is another embodiment in which the lightning protection device of the present invention is attached to a conventional earth leakage breaker. The circuit further includes inter-ground protection elements (Z2, Z3), and the protection effect when the resistance including the ground of the power supply line (n) is very large and the ground resistance of the ground circuit (G) of the load circuit is very small. It is a way to increase.

Figure 8c is another embodiment in which the lightning protection device of the present invention is attached to a conventional earth leakage breaker. The circuit further includes a protection device (Z2, Z3), an impedance (X2) and a discharge type device (G2) between the grounds, and is a method for increasing the protection effect.

9 is a picture of a real product of a circuit breaker having a lightning protection function manufactured by integrally providing the lightning protection device and the conventional circuit breaker 10 of the power supply in one case.

As mentioned above, although preferred embodiment of this invention was described in detail with reference to drawings and an example, this invention is not limited to the said embodiment, The person of ordinary skill in the art within the technical idea and the scope of the present invention is understood. Many variations and modifications are possible.

1 is a circuit diagram of a conventional earth leakage breaker;

2 is a surge protection circuit diagram applied to a conventional load circuit.

3 is a basic circuit diagram of a conventional lightning protection device for a single phase power supply,

4 is an embodiment of a lightning protection device of a power source according to the present invention;

5 is another embodiment of a lightning protection device of a power source according to the present invention;

Figure 6 is another embodiment of a lightning protection device of a power source according to the present invention,

Figure 7 is another embodiment of a lightning protection device of a power source according to the present invention,

8 are embodiments of a circuit breaker having a lightning protection function according to the present invention,

9 is a real product picture of a circuit breaker having a lightning protection function according to the present invention.

Explanation of symbols on the main parts of the drawings

L, N (n): Power input terminal G: Ground

Z, Za to Zc, Z1 to Zn: Suppression type surge protection device (varistor)

G1, G2: discharge type element

X1, X2: Impedance Element

Claims (7)

In the lightning protection device for a power source provided with a power supply line of a multi-phase multi-wire including a pair of power supply lines (L, n), The protection module 100 between the two lines (L, n) selected from the power line of the multi-phase multi-line, The protection module 100 includes a varistor element Z1, a discharge type device G1 connected in series with the varistor element Z1, and an impedance X1 connected in parallel with the discharge type device G1. , The withstand voltage of the varistor element Z1 and the discharge start voltage of the discharge type element G1 are lower than the maximum voltage value of the commercial power supply voltage. The magnitude of the voltage distributed to the varistor element (Z1) and the discharge type device (G1) is adjusted by the impedance (X1). The method of claim 1, A grounding wire is present in the power line of the multiphase polywire, The protection module 100 is provided between all power lines constituting the power line of the multiphase multi-line except for the ground line. A lightning protection device for a power supply, characterized in that varistor elements (Z2, Z3) are provided between each power line (L, n) and a ground line (G). The method of claim 2, A grounding wire is present in the power line of the multiphase polywire, The lightning protection device of the power supply, characterized in that the protection module 200 is provided in each of the power line constituting the power line of the multi-phase multi-line except for the ground line and the ground line. The method of claim 1, A ground wire and a neutral wire (N) exist in the power line of the multiphase multiwire, The protection module 200 is provided between a power line selected from a power line constituting the power line of the polyphase polyline except for the ground line and the neutral line. The neutral wire N is drawn out at the connection point between the varistor Z2 and the discharge type device G2 of the protection module 200, And a varistor element (Z3, Zn) is provided between the neutral line (N) and the power line of each of the polyphase polywires. The method of claim 1, And said impedance (X1) is a capacitor, a resistor or a varistor element. A circuit breaker having a lightning protection function, characterized in that the lightning protection device of any one of the power supply selected from claims 1 to 5 is provided at the front end, the rear end, or the front end and the rear end of the circuit breaker (10) or the circuit breaker. The method of claim 6, Lightning protection device of the power supply and the circuit breaker having a lightning protection function, characterized in that the circuit breaker (10) or the circuit breaker is integrally provided in one case.

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