KR100723887B1 - The surge voltage preventing system in an uninterruptible electric power distribution construction - Google Patents

Abstract

The present invention relates to a surge voltage preventing device in an uninterruptible power distribution method, and provides a surge voltage preventing device that can completely prevent the inflow of surge voltage generated in a power distribution construction by an uninterruptible power method.

According to the present invention, the ferrite bead portion 7 is disposed inside the blocking body portion located at the lower end of the electric shock prevention jaw, which is the clamp connection portion of the extra-high voltage riser cable 5, and the surge voltage suppression circuit 8 is provided with an uninterruptible transformer ( 4) At the same time, the ferrite bead portion 7 is disposed inside the low-voltage riser cable 6 similarly to the extra-high-voltage riser cable 5. In addition, the surge voltage suppressor circuit is connected to the capacitor (C1) and resistor (R1), the resistor (R2), and the resistor (R3) and varistor (VR) connected in series with each other in parallel to the It is connected to the power supply input lines R, S, T, U, V, and W, respectively, and one end thereof is drawn out to the ground line G.

Surge Voltage, Ferrite, Bead, Standing Cable, Transformer, Uninterruptible, Varistor, Resistor, Condenser, Snubber, Inductive

Description

Surge voltage preventing device in uninterruptible power distribution method {THE SURGE VOLTAGE PREVENTING SYSTEM IN AN UNINTERRUPTIBLE ELECTRIC POWER DISTRIBUTION CONSTRUCTION}

1 is a schematic diagram illustrating a power distribution construction by an uninterruptible construction method.

Figure 2a is an equivalent circuit diagram of a conventional high-voltage granular cable in the power distribution work by the uninterruptible method.

Figure 2b is a graph of the change in the surge current generated in the conventional high-voltage granular cable in the power distribution work by the uninterruptible method.

3A is a structural diagram of a clamp connection part of an extra-high voltage riser cable;

3B is a perspective view of the ferrite bead portion.

3C is a perspective view of a portion of the ferrite bead section cut away;

4A is an equivalent circuit diagram of an extra-high voltage granular cable in which ferrite bead portions are internally connected.

Figure 4b is a graph of the change in the surge current generated in the extra-high voltage granular cable in which the ferrite bead portion is internally connected.

5 is a surge voltage suppression circuit diagram.

6 is a structural diagram of a clamp connection part in a low-voltage riser cable;

Figure 7a is an equivalent circuit diagram of a conventional low voltage riser cable.

7B is an equivalent circuit diagram of a low voltage granular cable in which a surge voltage suppression circuit and a ferrite bead part are internally connected.

The present invention relates to a surge voltage protection device in an uninterruptible power distribution method, and more particularly, to a surge voltage prevention device in an uninterruptible power distribution method that can completely prevent the inflow of surge voltage generated in a power distribution construction by an uninterruptible power method. will be.

In spite of the recent surge in electric power demand, the power equipment required for this needs to be rapidly expanded, but the demand level of electric quality of electric power consumers is increasing. Reflecting such a situation, in recent years, the uninterruptible construction method that performs power distribution work without cutting off power for the purpose of supplying high quality power has been performed.

According to the power distribution work by the uninterruptible construction method, as shown in FIG. 1, a vehicle equipped with an uninterruptible transformer 4, standing cables 5 and 6 necessary for a work section, etc. are generally provided. Is connected to the distribution lines 1 and 2, respectively, and bypasses the supply of electric power, thereby replacing and relocating the distribution lines while maintaining power supply to the customer. In other words, even if the corresponding line section to perform maintenance work is maintained in a power outage state, since the electric power that is bypassed and transmitted through the transformer 4 and the riser cables 5 and 6 is continuously supplied from the health section to the customer side, The uninterrupted stable power is supplied to the line connection area and the customer.

However, in the process of connecting the extra-high voltage riser cable 5 to the extra-high voltage distribution line 1, a charging current is generated due to the capacitance component of the extra-high voltage riser cable 5. Due to such a charging current, a high voltage surge voltage is generated between the processing ground line N and the low voltage of the columnar transformer 3, and eventually, the surge voltage flows into the power consumer side, causing various fatal damages.

FIG. 2A shows an equivalent circuit of a conventional high-voltage granular cable in a power distribution construction by an uninterruptible method, and FIG. 2B shows a change in the magnitude of surge current generated in this case.

For example, in the case of the extra-high voltage distribution line, the amount of surge current generated depends on the length of the extra-high voltage riser cable 5 which bypasses the current, and as the length increases, the capacitance increases, resulting in an increase in the surge current. do. However, since alternating current is normally used, surge current is generated only when the extra-high voltage riser cable is connected to a point where the voltage crest value is high. However, since the AC voltage generally used has a frequency of 50/60 Hz, it is impossible to artificially connect the voltage near the point where the voltage peak value becomes 0V.

As a means for preventing the introduction of such surge voltage, in the case of low voltage equipment, a varistor is often used in the power supply device, but the power supply device is often damaged due to the surge voltage exceeding the breakdown voltage of the varistor. This is because most low-voltage devices have a built-in fuse, but since the fuse is a solid melt, a considerable amount of energy is required to break the fuse, whereas a surge voltage does not have enough energy to melt and blow the fuse. .

In addition, due to the inflow of the surge voltage, the earth leakage breaker in the distribution panel of the low voltage power consumer malfunctions, causing a power failure of the consumer, and even causing damage to the integrated power meter. In addition, the inflow of surge voltage not only causes frequent failure of the uninterruptible transformer 4, but also generates harmful electromagnetic waves, and in particular, causes a malfunction of the traffic signal controller when the traffic signal controller is near the pole transformer 3. do.

Thus, the present invention was devised to solve the above problems, an object of the present invention is an uninterruptible power distribution method that can completely prevent the surge voltage generated in the power distribution construction by the uninterruptible method flows into the consumer side To provide a surge voltage suppressor.

As a feature of the present invention for achieving the above object, the surge voltage preventing device in the uninterruptible power distribution method according to the present invention is connected to each of the high-voltage high-voltage cable and low-voltage power cable connected to the distribution line, the uninterruptible transformer is connected In the surge voltage prevention device installed in the uninterruptible power distribution equipment for supplying power to the customer in an uninterruptible state, the extra-high voltage cable and the low-voltage cable includes a ferrite bead surrounding the inner copper wire, The uninterruptible transformer is characterized by having a surge voltage suppression circuit including a varistor and an inductive resistor therein.

In addition, as another feature of the present invention, the surge voltage suppressor circuit includes a capacitor (C1) and a resistor (R1) connected in series with each other, a resistor (R2), a resistor (R3) and a varistor (VR) connected in series with each other. It is connected in parallel to each of the power input lines (R, S, T, U, V, W) of the uninterruptible transformer, one end of which is characterized in that it has a common wire drawn out to the ground line (G).

In addition, as another feature of the present invention, the bead is characterized in that it is disposed inside the blocking body portion which is located at the lower end of the electric shock prevention jaw which is the clamp connection portion of the extra-high voltage riser cable or the low-pressure riser cable.

In addition, as another feature of the present invention, the outside of the bead is characterized in that the molding with a synthetic resin material.

In addition, as another feature of the present invention, the resistors (R1, R2, R3) is characterized in that the non-inductive resistor.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail. However, the embodiments described below are provided to help the overall understanding of the present invention, and the present invention is not limited to the above embodiments.

FIG. 3A is a structural diagram of the clamp connection portion in the extra-high voltage riser cable, FIG. 3B is a perspective view of the ferrite bead portion 7, and FIG. 3C is a perspective view of a portion of the ferrite bead portion 7 cut away.

First, in the case where the extra-high voltage riser cable 5 is connected to the extra-high voltage distribution line 1 by clamp connection as shown in FIG. 1, the ferrite bead portion 7 is connected to the extra-high voltage riser cable 5 as shown in FIG. 3A. Insert the cable inside the line connection part and connect the cable.

As shown in FIGS. 3B and 3C, the ferrite bead part 7 has a structure in which a ferrite bead 71 surrounding the copper wire 73 is enclosed. In order to protect, the synthetic resin material 72 molds the outside thereof.

The ferrite bead part 7 is connected to the interior of the MC nylon blocking body 52 positioned at the lower end of the electric shock prevention jaw 51, which is a connection part of the extra-high voltage granular cable 5, and an equivalent circuit thereof is shown in FIG. 4A. Same as That is, since the inductance L is increased due to the ferrite bead 71 to increase the magnetoresistance, the charging current generated in the extra-high voltage granular cable 5 can be reduced as shown in FIG. 4B.

In addition, a varistor and an inductive resistor are connected inside the uninterruptible transformer 4 to dissipate the surge voltage generated by the extra-high voltage riser cable 5 by heat.

That is, the surge voltage suppressor 8 shown in FIG. 5 is provided inside the uninterruptible transformer 4. The surge voltage suppressor 8 includes a snubber circuit in which a capacitor C1 and a resistor R1 are connected in series to each power input line R, S, T, U, V, and W, and a resistor R2. ) And the varistor VR connected in series with the resistor R3 are connected in parallel, and a common wire drawn out to the ground line G is connected at one end thereof.

Therefore, when the generated surge voltage is higher than the breakdown voltage of the varistor VR, the varistor VR breaks down, and the surge voltage is applied to the resistor R3 and radiated by heat. In addition, when the generated surge voltage is lower than the breakdown voltage of the varistor VR, the surge voltage is absorbed by the snubber circuit, and the surge voltage is charged through the resistor R1 after charging the capacitor C1. It is exhausted by gradually discharging with heat.

At this time, the value of the resistor R1 should be set to a value such that the capacitor C1 can be sufficiently discharged before the next charge is started, and the snubber circuit is configured such as the resistor R1 and the capacitor C1. In addition to the connection of, all of the capacitors or combinations of capacitors and other commonly used snubber circuits consisting of resistors and diodes are applicable.

In addition, the element used in the surge voltage suppressor circuit 8 is selected to have a sufficient withstand voltage capacity. The capacitor C1 uses a breakdown voltage film capacitor of about 6 KV, and the inductance component is 0 for the resistors R1 to R3. It is desirable to use inductive resistors close to to avoid delay effects due to inductance components.

Next, in the case where the low-voltage riser cable 6 is connected to the low-voltage distribution line 2 as shown in FIG. 6, the ferrite bead portion 7 having the same structure as shown in FIGS. 3B and 3C has been described above. In the same manner as described above, the low-voltage riser cable 6 is inserted into the blocking body 62 positioned at the lower end of the electric shock prevention jaw 61 of the clamp connection portion and connected.

In this case as well, the inductance value of the low-voltage riser cable 6 is increased and the charging current is attenuated in the same manner as in the case of the above-described high-voltage riser cable 5, and thus, the surge voltage suppression circuit 8 of the uninterruptible transformer 4 is not found. The unabated surge voltage component is canceled to completely block the opening / closing surge voltage generated during low voltage bypass to the power consumer.

That is, when the surge voltage suppression circuit 8 is provided inside the uninterruptible transformer 4 as described above, and the ferrite bead portion 7 is internally connected to the low voltage riser cable 6, an equivalent circuit thereof is shown in FIG. 7B. Becomes the same as Fig. 7A is an equivalent circuit diagram of a conventional low voltage riser cable.

As described above, according to the present invention, the ferrite bead portion 7 is internally connected to the clamp connection portion of the extra-high voltage riser cable 5, and the surge voltage suppression circuit 8 is provided inside the uninterruptible transformer 4 and at the same time low voltage is applied. The ferrite bead portion 7 is internally connected to the clamp connection portion of the riser cable 6.

As described above, according to the present invention, the ferrite bead portion 7 is internally connected to the clamp connection portion of the extra-high voltage riser cable 5, and the surge voltage suppression circuit 8 is provided inside the uninterruptible transformer 4. At the same time, the internal connection of the ferrite bead portion 7 to the clamp connection portion of the low-voltage granular cable 6 can completely prevent the inflow of surge voltage generated in the power distribution work by the uninterruptible method.

In addition, the preferred embodiment of the present invention is disclosed for the purpose of illustration, anyone of ordinary skill in the art will be possible to various modifications, changes, additions, etc. within the spirit and scope of the present invention, such modifications, changes, Additions and the like should be considered to be within the scope of the claims.

Claims (5)

delete delete In the surge voltage prevention device installed in the uninterruptible power distribution equipment that connects and connects the high-voltage and low-voltage riser cable to each distribution line, and connects the uninterruptible transformer to supply power to the customer in an uninterrupted state. The surge voltage suppressor is composed of a ferrite bead surrounding a part of copper wires inside the extra-high voltage riser cable and the low-voltage riser cable, and a surge voltage suppression circuit connected inside the uninterruptible transformer. The surge voltage suppressor includes a snubber circuit, a resistor (R3) and a varistor (VR) connected in series with the resistor (R2) in parallel and are connected to the power input lines (R, S, T, U, V, W of the uninterruptible transformer). And a common wire connected to the respective ones thereof and one end thereof drawn out to the ground wire G, The snubber circuit consists of a capacitor (C1) and a resistor (R1) connected in series with each other, And the bead is disposed inside a blocking body part positioned at a lower end of an electric shock prevention jaw, which is a clamp connection part of the extra-high voltage riser cable or the low-voltage riser cable. The apparatus of claim 3, wherein the exterior of the bead is molded with a synthetic resin material. 5. The surge voltage suppressor according to claim 3 or 4, wherein the resistor is a non-inductive resistor.

Images