KR101171227B1 - The protection device of high-speed communication lines for emp protection measures - Google Patents

Abstract

PURPOSE: A protection device for a high speed communication line for an EMP protection is provided to safely protect a communication network and electric and electronic apparatus connected to the rear of the protection device by minimizing the attenuation of a high speed communication signal. CONSTITUTION: An input terminal(X1,X2) receives an impulse voltage. A high frequency isolation transformer(T1) separates a primary side from a secondary side of a transformer. A common inductor(CM1) is connected to the high frequency isolation transformer and limits a current. An output terminal(Z1,Z2) is connected to a secondary side of the common inductor and supplies power to a load. A gas discharge tube is connected between the input terminal and the primary side of the high frequency isolation transformer in parallel.

Description

TECHNICAL PROTECTION DEVICE OF HIGH-SPEED COMMUNICATION LINES FOR EMP PROTECTION MEASURES

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protection device for a high speed communication line. More particularly, the present invention relates to a GDT, a high frequency insulation transformer, a high speed operation diode, a series resistor, a common mode inductor, and the like to improve the limit voltage and residual current characteristics. A protection device for

In the modern society where the Internet-based network environment is very common, the disruption of communication services due to electronic device disturbances may cause social chaos and enormous economic damage. These advanced electronic devices are rapidly being integrated and miniaturized to improve efficiency, and as a result, immunity to high-power interference sources such as high-altitude electromagnetic pulses (HEMP) is becoming weaker. Therefore, the application of the protection device is essential.

In general, in order to protect a communication device from a surge such as a lightning strike, a protective element such as a gas discharge tube (GDT) or a metal oxide varistor (MOV) is used in combination. However, Internet-based high-speed communication lines generally require high-speed signal transmission of about 100 MHz, and the devices that can be used to protect them from EMP without attenuation of signals are very limited. Surge protection device for high speed communication line, which is generally applied at present, is composed of a protection element such as GDT having a very small capacitor component simply connected in parallel with the line. This is because high-speed communication lines use high-frequency signals up to about 100MHz, which adversely affects the transmission of normal signals when a large capacitor component such as MOV is used. However, this type of protection device is very difficult to suppress the final residual current below the reference value, and the protection effect is insufficient for sensitive load devices.

The technical problem to be achieved by the present invention is effectively capable of effectively suppressing both a very steep short pulse current having a wave length of several tens ns and hundreds of ns and a heavy pulse current having a duration of about 5 ms with a microwave length of several milliseconds, and a high speed communication signal. By minimizing the attenuation of the present invention to propose a device for stably protecting the communication electrical and electronic equipment and communication networks connected to the rear end of the device.

High-speed communication line protection device for the EMP protection measures of the present invention, the input terminal (X1, X2) to which the impulse voltage is input, the high frequency isolation transformer (T1) configured to separate the transformer 1, secondary between the input terminal And a common inductor CM1 connected to the high frequency isolation transformer to limit current, and output terminals Z1 and Z2 connected to a secondary side of the common inductor to supply power to the load. Gas discharge tube (GDT1) connected in parallel between the primary side to discharge the impulse current flowing from the input terminal, and installed in parallel on the secondary side of the high frequency insulation transformer to suppress the voltage between Y1-Y2 terminals below the diode operating voltage. It includes a plurality of high speed operation diodes (D1, D2).

In addition, a plurality of high-speed diodes D3, D4, D5, and D6 disposed in parallel to suppress the impulse current between the line and the ground between the secondary side of the common inductor CM1 and the loads RL1 and RL2 are included. do.

In addition, the secondary side of the series resistor (R1, R2) and the common inductor (CM1) and the load (RL1) connected in series between the impulse voltage input terminal (X1, X2) and the high frequency isolation transformer (T1) to limit the current flow. , Series resistors R3 and R4 connected in series between RL2 to limit current flow.

In addition, when the impulse is input from the input terminal GDT1 and a high voltage is applied between the input terminal X1 (or X2) and the ground (G), the gas discharge tube discharges between AC (or BC). Most of the input pulse current is discharged to ground.

In addition, the high frequency isolation transformer T1 is configured to reduce the pulse coupling to the rear end of the transformer by separating transformers 1 and 2, thereby improving residual current characteristics.

Also, the plurality of high speed operation diodes D1 and D2 operate when the positive pulse is generated between the Y1 and Y2 terminals of the secondary side of the high frequency insulation transformer, and the high speed operation diode D2 operates when the negative pulse occurs. The type diode D1 operates to limit the voltage between the Y1-Y2 terminals below the diode operating voltage.

In addition, a plurality of the high speed operation type diodes are used in series according to the voltage peak value of the steady state of the line to be protected.

In addition, the plurality of high speed operation diodes D3, D4 or D5, D6 installed between the line and the ground between the secondary side of the common inductor CM1 and the loads RL1 and RL2 may operate at high speed when a positive pulse occurs. When diode D3 or D5 operates and a negative pulse occurs, the fast-acting diodes D4 or D6 operate to limit the line-to-ground voltage below the diode operating voltage.

In addition, the impulse current is limited by using the forward voltage drop characteristics of the high speed operation diodes D1 to D6 and the attenuation of the normal signal by the series connection of the plurality of high speed operation diodes is prevented.

In addition, the common inductor CM1 suppresses the transfer of the pulse current to the load terminal by suppressing the common mode current when the impulses are simultaneously applied to the X1-G and X2-G terminals, and for the normal signal transmitted in the differential mode. It doesn't affect it.

The present invention is a gas discharge tube 110, a high frequency insulation transformer 310, a high-speed operation diode (401 ~ 406), series resistance as a protective device for a high-speed signal line against EMP that can be generated by lightning, surge, high-altitude nuclear explosion, etc. By combining the 201 to 204 and the common mode inductor 320, it is possible to implement an economical and reliable protection device even for an impulse current having a very fast rise time.

When such a protective device is installed in front of equipment for high speed communication lines such as LAN, it is possible to prevent trouble caused by EMP and to enable stable communication operation.

1 is a block diagram of a high speed communication line protection device according to the present invention.
2 is an explanatory view of the operation of the high-speed communication line protection device of FIG.
3 is an explanatory view illustrating the operation of the high speed communication line protection device of FIG. 1.
4 is a waveform diagram illustrating residual current measurement for a short pulse applied current according to the present invention.

Currently, the standard (MIL-STD-188-125- 1/2) related to the performance test of the protective device for the EMP countermeasures has a critical impulse current that can occur in the signal line due to the EMP. It is divided into fast pulses and several pulses and heavy pulses of several ms. The short pulse current is a very steep waveform and the fast response characteristic of the protection device is required. The heavy pulse current is a large current waveform such as an impulse current whose energy content is caused by lightning. In the present invention, a protection circuit for suppressing the residual current of the output terminal of the protector to 0.1 A or less, which is a standard reference value, is described for the two current waveforms.

1 is a block diagram of a high speed communication line protection device according to the present invention. As shown in FIG. 1, the protection device includes a gas discharge tube 110, a series resistor 201, 202, 203, 204, a high frequency insulation transformer 310, a high speed operation type diode (401 ˜ 406), and a common mode inductor 320. It is composed. In order to facilitate understanding of the present invention, a LAN communication line having a signal characteristic of a protected object having a peak value of 1 V or less and a maximum transmission frequency of 100 MHz will be described as an example, and the present invention may be applied to other signal lines having similar characteristics. That's the way it can be.

The operation principle of the protection device against the EMP pulse current is explained by the short pulse and the resistance load (205, 206) simulating the protected device to be connected between the output terminal of the protector and the ground to measure the residual current of the protection device. The middle pulse applies a pulse voltage between X1 and ground (G) or X2 and ground, which is an input terminal of the protection device of FIG. 1, to apply a pulse current to X1 or X2. First, assuming that a pulse voltage is applied between X1 and G, when the voltage generated between the AC terminals reaches the ignition voltage value of the gas discharge tube 110 due to the increase in the pulse voltage, the gas discharge tube 110 as shown in FIG. A discharge occurs between the AC terminals and a short circuit condition causes most of the pulse current applied between X1 and ground (G) to discharge to the ground side through the shorted AC terminal. In addition, by separating the first and second transformers by the high-frequency insulation transformer 310 to reduce the pulse current coupling to the rear end of the transformer to improve the residual current characteristics.

However, the pulse current applied before the discharge between the AC terminals of the gas discharge tube 110 is generated is the primary side winding 311 and the series resistance 202 and gas of the series resistance 201 and the high frequency insulation transformer 310. It flows through the parasitic capacitor 111 between the B and C terminals of the discharge tube 110, which is generated by the high-frequency insulation transformer 310 at both ends of the secondary winding 312 of the transformer in the form of LC vibration waves. At this time, the series resistors 201 and 202 are used to limit the current flowing in the primary side winding 311 of the high frequency insulation transformer 310.

Since the peak value of the vibration waveform may exceed the reference value specified in the specification, the fast-acting diodes 401 and 402 are disposed in parallel with respect to the differential mode in order to suppress them. The high speed operation diodes 401 and 402 have only a few pF of capacitance and a fast recovery speed of 4 ns or less, and thus do not affect LAN communication as a target line. At this time, since the diode must operate for both the positive and negative pulses, the two diodes are used in parallel combination in the opposite direction.

2 is an explanatory view of the operation of the high-speed communication line protection device of FIG. In FIG. 2, when the positive pulse is generated between the Y1-Y2 terminals on the secondary side of the high frequency insulation transformer 310, the high speed operation diode 402 operates. When the negative pulse occurs, the high speed operation diode 401 operates. This structure suppresses the voltage between the Y1-Y2 terminals below the diode operating voltage.

  In general, since the forward operating voltage of diode is about 0.7 ~ 1V, it can be used in series according to the steady state voltage peak value of the line to be protected. As an example, since the steady state voltage of a typical LAN line is about 2V, two or three high speed diodes are used in series.

3 is an explanatory view illustrating the operation of the high speed communication line protection device of FIG. 1. The high frequency isolation transformer 310 restricts the transition of large currents in the low frequency band, but for short pulse currents having a very high frequency, current may be transferred to the secondary side due to the capacitor components 313 and 314 across the high frequency isolation transformer 310. Can be. That is, in the case of an ideal transformer, there is no capacitor component between the primary and secondary windings 311 and 312, but in the case of an actual transformer, there is a capacitor component of about 1 pF or more due to physical characteristics.

는

이다. 여기서 c는 고주파 절연변압기(310) 1, 2차간의 커패시터 성분(313, 314)이다. c가 1pF이라 가정하고 인가되는 단펄스 전류의 파형의 상승시간이 20 ns, 충전전압이 30 kV라고 가정하면 전류

는 아래와 같다.FIG. 3 is a diagram for describing a current transmitted through capacitor components 313 and 314 of a transformer, and capacitor components 313 and 314 exist between a primary side and a secondary side of the high frequency insulation transformer 310. The magnitude of the short pulse current transitioned to the secondary side by the capacitors 313 and 314 is as follows. Current flowing through capacitors 313 and 314

The

to be. Where c is the capacitor components 313 and 314 between the high frequency insulation transformer 310 and the first and second orders. Assuming that c is 1 pF, assuming that the rise time of the waveform of the applied short pulse current is 20 ns and the charging voltage is 30 kV

Is shown below.

Since a current of this magnitude can be generated on the secondary side of the high frequency insulation transformer 310, a high speed operation type diode 403 to 406 is applied between the line and the ground to suppress the current. The high speed operation diodes 403 to 406 have a structure connected in parallel to the front end of the resistors 205 and 206 on the load side, and short-circuit the circuit before the transferred impulse current reaches the load side. 406) It restrains the residual current by limiting the voltage at the rear end below the diode operating voltage. It operates in the same manner as the high speed operation type diodes 401 to 402 described above, and uses two diodes connected in parallel in the reverse direction to operate also for the positive and negative polarities. The series resistors 203 and 204 function to limit the current by reducing the voltage generated on the load side through the voltage distribution effect. In addition, when the EMP pulse current is applied to the X1-G and X2-G terminals simultaneously by applying the common mode inductor 320, the common mode current is suppressed to suppress the pulse current transfer to the load stage, and is transmitted in the differential mode. Do not affect the normal signal.

Figure 4 is an example of a waveform measured by the oscilloscope response characteristics for short pulse current of the protection device implemented in accordance with the present invention. The upper waveform of FIG. 4 is a current waveform applied to the protector, measured at point M1 of FIG. 3, and the lower waveform of FIG. 4 is a waveform measured at point M2 of FIG. 3 as the output terminal current of the protector. According to the waveform of FIG. 4, when an impulse current of about 1000A is applied between X1 and G, only a very small current of 57.8 mA flows through the load stage, thereby demonstrating that it is sufficiently effective for protecting the load device.

Claims (10)

Input terminals (X1, X2) to which an impulse voltage is input, a high frequency isolation transformer (T1) connected to the input terminal and configured to separate transformers 1 and 2, and a common inductor connected to the high frequency isolation transformer to limit current ( CM1) and output terminals Z1 and Z2 connected to the secondary side of the common inductor to supply power to the load.
A gas discharge tube (GDT1) is connected in parallel between the input terminal and the primary side of the high frequency insulation transformer to discharge an impulse current flowing from the input terminal, and a plurality of high speed operation diodes D1 and D2 in parallel to the secondary side of the high frequency insulation transformer. ) To suppress the voltage between the Y1-Y2 terminals below the diode operating voltage,
A plurality of high speed operation diodes are connected between the secondary side of the common inductor CM1 and the loads RL1 and RL2 to the upper lines D3 and D4 and the lower lines D5 and D6 of the common inductor secondary side. Each installed in parallel to suppress this when the impulse current inflow,
The secondary side of the series resistors R1 and R2 and the common inductor CM1 and the loads RL1 and RL2 connected in series between the impulse voltage input terminals X1 and X2 and the high frequency isolation transformer T1 to limit current flow. Protective device for a high-speed communication line for the EMP protection measures, characterized in that it comprises a series resistor (R3, R4) connected in series to limit the current flow. delete delete The method of claim 1,
When the impulse is input from the input terminal and a voltage is applied between the input terminal (X1 or X2) and the ground (G), the gas discharge tube (GDT1) is discharged between AC or BC, and is short-circuited. The high-speed communication line protection device for the EMP protection measures characterized in that the pulse current is discharged to the ground side. The method of claim 1,
The high frequency isolation transformer (T1) is separated from the first and second transformer, to reduce the pulse coupling to the rear end of the transformer to improve the residual current characteristics, characterized in that for protecting the high speed communication line for the EMP protection measures . The method of claim 1,
The plurality of high speed operation diodes D1 and D2 operate as the high speed operation diode D2 when a positive pulse occurs between the Y1 and Y2 terminals of the secondary side of the high frequency insulation transformer, and when the negative pulse occurs, the high speed operation diode D1. High speed communication line protection device for the EMP protection measures, characterized in that the operation. The method of claim 1,
The high speed operation type diode protection device for a high speed communication line for the EMP protection measures, characterized in that a plurality of in series in accordance with the voltage peak value of the steady state of the line to be protected. The method of claim 1,
The plurality of fast-acting diodes D3, D4, D5, or D6 disposed between the line and the ground between the secondary side of the common inductor CM1 and the loads RL1 and RL2 are fast-acting diodes D3 when a positive pulse is generated. Or D5 operates, and a high speed operation type diode D4 or D6 operates when a negative pulse is generated. The method of claim 1,
EMP protection measures for limiting the impulse current by using the forward voltage drop characteristics of the high speed operation diodes D1 to D6 and preventing attenuation of the normal signal by series connection of a plurality of high speed operation diodes. High speed communication line protection device. The method of claim 1,
The common inductor CM1 suppresses the transfer of pulse current to the load stage by suppressing the common mode current when impulses are simultaneously applied to the X1-G and X2-G terminals, and affect the normal signal transmitted in the differential mode. High speed communication line protection device for EMP protection measures, characterized in that not to fall.

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