KR200322546Y1 - Common terminal block installed with a current transformer by which a power line failure can be monitored by naked-eyes - Google Patents

Abstract

Disclosed is a common connecting terminal block equipped with a current transformer assembly capable of visually recognizing an energized state of a power system line. One or more conductor bars are arranged on the top of the insulating terminal support, and each terminal bar is screw-assembled to the terminal support while each conductor bar is inserted into the current transformer assembly. The current transformer assembly includes a current transformer for interpolating a current flowing through the conductor bar by interpolating the conductor bar, a light emitting device that emits light while a driving current is input, and a driving circuit that receives the output current from the current transformer and provides a driving current to the light emitting device. The light emitting device and the driving circuit are assembled to the upper portion of the current transformer in a state of being assembled on a printed circuit board, and at least the light emitting device is exposed to the outside to visually identify whether light is emitted. If necessary, a conductive common connecting bar for connecting the pair of conductor bars in common is arranged to be screwable to the terminal support while crossing over the set of conductor bars. According to the present invention, the energized state of the power system can be confirmed through whether the light emitting diode of the current transformer assembly emits light, so that an accident due to opening the current transformer during maintenance or replacement of the device can be prevented.

Description

Common terminal block installed with a current transformer by which a power line failure can be monitored by naked-eyes}

The present invention relates to a common terminal block of a current transformer (CT) of a power system circuit, and more specifically, to a common terminal block of a current transformer connected to an installed peripheral current transformer of a power distribution line, a function of visually identifying a state of energization of a circuit. It is further related to the improvement of the common terminal block.

In general, in case of transmission and distribution lines under high voltage, a current transformer is installed to monitor the failure or condition of the line. The primary current ratings of the current transformers vary from tens of amps to thousands of amps, but the secondary currents are rated at 5 amps [A]. Current transformers are different from transformers, so it is safe to short the secondary, but it is dangerous to open them. This is because when the secondary is opened, the primary current acts to magnetize all the iron cores so that the iron cores saturate and generate heat. If the heat is severe, the current transformer can be burned out.

Figure 1 shows a part of the power system of the 154KV transmission line of KEPCO, the line 10, including the devices for the line breakage in the event of a failure, such as a gas type circuit breaker (GCB), the power of the line 10 Current transformers 20a and 20b are installed to monitor the condition. Since the power system is a three-phase line, these current transformers 20a and 20b are generally installed in each phase.

Typically, the current transformer is formed by winding a primary coil with a small number of windings and a secondary coil with a large number of windings on a stratified core. In the secondary coil, when the current transformer is a measuring CT 20a, a power meter (W, A meter such as Var) or an ammeter A is connected, and in the case of a line protection CT 20b, a line protection device such as a relay is connected. Such measuring devices and line protection devices are generally connected through common connection terminal blocks 30 and 40, respectively.

If work is to be carried out for the inspection and maintenance of the measuring instruments or line protection devices connected to the current transformers 20a or 20b or for the replacement of equipment in the event of a failure of these devices, the secondary side of the current transformers 20a or 20b must be opened. none. However, as mentioned above, opening of the secondary side of the current transformer causes burnout of the current transformer. Therefore, even when performing maintenance or replacement of various devices connected to the secondary side of the current transformers 20a and 20b, the secondary side of the current transformers 20a and 20b should not be made open. To this end, the common connecting terminal blocks 30 and 40 are disposed between the secondary side of the current transformers 20a and 20b and the measuring device (or the line protection device) to connect them. This common connection bar serves to make a common connection of a set of three-phase terminals connected to the common connection terminal block (30, 40). Before disconnecting various measuring instruments and line protection equipment from the secondary side of the current transformers 20a and 20b, the secondary side of the current transformers 20a and 20b is short-circuited using this common connecting bar. Then, the current transformers 20a and 20b can still be kept short-circuited even if the various measuring instruments or line protection devices connected to the secondary terminals of the common connection terminal block 30 and 40 are disconnected from the secondary terminals. You can do it.

However, in the conventional common connection terminal block, whether current flows in the conductor bar in the common connection terminal block connecting the secondary side of the current transformers 20a and 20b and the measuring device (or line protection device), that is, the current flows in the current transformers 20a and 20b. It was a configuration that could not be visually identified from the outside whether or not it was induced. Therefore, during maintenance or replacement of the measuring instrument or the line protection device, the operator must accidentally omit or short the procedure of shorting the secondary side using the common connecting bar before opening the secondary side of the current transformers 20a and 20b. There is a case of making a mistake in shorting the secondary side of a current transformer other than the current transformer. Since several common connection terminal blocks are installed in the common connection terminal box, there is a possibility that a mistake of the above operator may occur.

The present invention can visually identify the energized state of a monitoring / protection circuit using a measuring current transformer or a protective current transformer, which is essential for power systems such as transmission and distribution lines, to monitor the life and death of the circuit, It is an object of the present invention to provide a device capable of preventing damage to power equipment by preventing the opening of the current transformer in advance.

Detailed description of the embodiments of the present invention will be made with reference to the accompanying drawings, the number designating the corresponding parts in the drawings are the same.

1 shows an example of a power system in which a common terminal block according to the present invention is installed.

2A and 2B are a plan view and a perspective view of a common terminal block in which a current monitoring current transformer assembly according to the present invention is installed.

Figure 3a is a cross-sectional view showing a configuration according to an embodiment of the current transformer assembly according to the present invention.

Figure 3b is a cross-sectional view showing a configuration according to another embodiment of the current transformer assembly according to the present invention.

Figure 3c is a cross-sectional view showing a configuration according to another embodiment of the current transformer assembly according to the present invention.

4 shows a circuit configuration of the current transformer assembly 60.

5 illustrates a part of a common connection terminal box constructed by using the common connection terminal block illustrated in FIG. 2A (or 2B).

** Explanation of symbols for main parts of drawings **

20a, 20b: Current transformers 30, 40: Current transformer installation common terminal box

50, 50a, 50b: common terminal block 52: terminal stand

54a ~ 54d: Conductor bar 56: Conductive common bar

60, 60a to 60d: conditional current transformer assembly

62, 62 ', 62 ", 62a-62d: light emitting diodes

64, 64 ', 64 ": printed circuit board

66, 66 ', 66 ": Case 68, 68', 68": Coil

72a ~ 72d: Primary Side Connection Line 72a '~ 72d': Secondary Side Connection Line

According to the present invention for achieving the above object, at least one or more terminal supports made of an insulating material is disposed, at least one conductor bar is disposed on the upper surface of each terminal support, each conductor bar is inserted into the current transformer assembly, both terminals thereof Screwed to the terminal support, the current transformer assembly is a current transformer to interpolate the current flowing through the conductor bar by interpolating the conductor bar, a light emitting device to emit light while a drive current is input, and receives the output current from the current transformer the light emitting device And a driving circuit for providing the driving current, wherein the light emitting device and the driving circuit are visually identified whether the light emitting device emits light while being assembled on the upper portion of the current transformer while being assembled on a printed circuit board. Exposed to the outside to provide a set of conductor bars, A CT common terminal block is characterized in that a conductive common connecting bar for connecting to a common connection is disposed across the conductor bar to be screwed to the terminal support. Is provided.

In the current transformer common connection terminal block, the current transformer assembly is preferably assembled with the printed circuit board and the current transformer in one case so that only the light emitting element is exposed to the outside of the case. As another alternative, the current transformer assembly is assembled such that only the current transformer is embedded in the case and the printed circuit board and the light emitting element mounted thereon are exposed to the outside of the case.

In addition, the light emitting device is a light emitting diode (LED), the driving circuit is supplied to the light emitting diode only the current amount necessary for the light emitting diode to operate stably among the output current of the current transformer is not supplied to the light emitting diode. It is configured to bypassing.

Furthermore, a plurality of common connection terminal blocks of any one of claims 1 to 4 are disposed inside the terminal box, and the primary terminal of the conductor bar of each common connection terminal block is an output terminal of a main current transformer coupled to a three-phase high voltage transmission and distribution line. Is connected to, and the secondary terminal of the conductor bar is provided with a common connection terminal box, characterized in that the line protection device such as a measuring instrument or a protective relay for measuring the amount of electricity, such as current or power of the transmission and distribution line.

Other features and advantages of the present invention will become more apparent with reference to the following detailed description and accompanying drawings that illustrate the features of various embodiments of the invention. Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

2A and 2B are a plan view and a perspective view showing a configuration of a common connection terminal block 50 according to an embodiment of the present invention. The common connection terminal block 50 includes a terminal support 52, a plurality of conductor bars 54a to 54d, a conductive common connection bar 56, and auxiliary current transformer assemblies 60a to 60d.

The terminal support 52 is made of an insulating material, and a plurality of conductor bars 54a to 54d, auxiliary current transformer assemblies 60a to 60d, and a conductive common connecting bar 56 are installed on an upper surface thereof. In order to facilitate the installation, the upper surface of the terminal support 52 has a square groove formed at the center of the terminal box, leaving only both ends for screw assembly in the terminal box. 'Made in a shape. And in the center of the groove again, small grooves are formed in a line. The partition 58 may be further formed on the upper surface of the terminal support 52 to separate each phase.

Auxiliary current transformer assemblies 60a to 60d are inserted in a line in small grooves formed in the upper surface of the terminal support 52. Each of the auxiliary current transformer assemblies 60a to 60d has one conductor bar 54a to 54d inserted therein. In some cases, the conductor bars may be interpolated by winding the center portion of the auxiliary current transformer assembly in several turns. Each of the conductor bars 54a to 54d is arranged side by side, and both ends thereof are connected to the terminal support 52 by screws. It has a structure to be assembled. The primary sides 54a'-54d 'of the conductor bars 54a-54d are connected to the outputs of the peripheral current transformers (for example, 20a or 20b of FIG. 1) connected to the power system, and the secondary sides 54a "-54d" It is connected to measuring instruments such as a power meter or an ammeter (if the peripheral current transformer is a measuring current transformer) or to a relay (if the peripheral current transformer is a line protection current transformer). In other words, three of the conductor bars 54a to 54d are connected one-to-one to three peripheral current transformers connected to the three-phase line of the power system, and the other is connected to the neutral wire.

In addition, the conductive common connecting bar 56 is disposed while crossing the pair of conductor bars 54a to 54d. If you want to connect a set of conductor bars 54a to 54d for common maintenance or replacement of various measuring instruments or line protection devices connected to the secondary side of them, connect them to the terminal support 52 by screw assembly. You can fix it.

Current transformer assembly 60 of the present invention is configured using an auxiliary current transformer, a light emitting diode and a driving circuit. 4 shows a circuit configuration of the current transformer assembly 60. In FIG. 4, driving circuits are connected to both ends of the coil of the auxiliary current transformer 68 to provide a driving current to a light emitting diode (LED) which receives an output current from the auxiliary current transformer and functions as a light emitting device. The driving circuits C, D1, R, D2, and TR play a role of appropriately adjusting the amount of driving current so that the light emitting diode can be driven stably. That is, the output current of the auxiliary current transformer 68 varies in magnitude depending on the amount of current flowing through the conductor bar 54 interpolated therewith. However, the function required for the light emitting diode (LED) is that when the current flows in the conductor bar 54, it should emit light stably whether the value is small or large. If the output current of the auxiliary current transformer 68 is excessively large, supplying all of them to the light emitting diodes (LEDs) greatly shortens the lifespan of the light emitting diodes. Conventional light emitting diodes start emitting light when the drive current is about several mA or more, and can be used stably for a long time within about 22 to 25 mA. If the value exceeds this value, the lifespan is shortened. In consideration of this, it is necessary to configure the driving circuit so that only the amount of current necessary for stable driving of the light emitting diode is supplied to the light emitting diode and the remaining current is bypassed.

In the driving circuit of FIG. 4, the current induced in the coil of the auxiliary current transformer 68 has a light emitting diode (LED) through the diode (D1) after charging the capacitor (C) until the value exceeds the threshold. When only the current flows into the ground but the current exceeds the threshold, the transistor TR is turned on by the voltage applied to the resistor R, and the excess current is bypassed through the diode D2 and the transistor TR. Therefore, the LED does not flow beyond the threshold value and thus can be driven stably.

Figure 3a is a cross-sectional view showing a configuration according to an embodiment of the current transformer assembly according to the present invention. According to the structure of the current transformer assembly 60 shown, the auxiliary current transformer 68 is embedded in the molding case 66, and the light emitting diode 62 and its driving circuit 67 are assembled to the printed circuit board 64. The printed circuit board 64 is supported by the supports 65a and 65b and is fixed to the upper surface of the case 66. The auxiliary current transformer 68 and the driving circuit are connected through the connection leads 69a and 69b.

Figure 3b is a cross-sectional view showing a configuration according to another embodiment of the current transformer assembly according to the present invention. In the current transformer assembly 60 'according to this embodiment, a printed circuit board 64' in which a driving circuit is mounted is embedded in the molding case 66 'together with the auxiliary current transformer 68', and outside the case 66 '. It is characterized in that only the light emitting diode 62 'is exposed.

Figure 3c is a cross-sectional view showing a configuration according to another embodiment of the current transformer assembly according to the present invention. The current transformer assembly 60 " according to this embodiment is formed in a substantially circular shape on the side of the auxiliary current transformer 68 " by making the printed circuit board 64 " Only the light emitting diode 62 "is exposed to the outside of the case 66".

The common feature of the above embodiments is that at least the light emitting diodes are exposed to the naked eye so that they can be visually identified from the outside, and are made of an integrated module considering the convenience of insertion coupling with the conductor bar 54.

5 illustrates a part of a common connection terminal box constructed by using the common connection terminal block illustrated in FIG. 2A (or 2B). As shown in the drawing, a plurality of common connection terminal blocks 50a and 50b are arranged in a vertical line. The primary side 54a'-54d 'of the conductor bar of each common connecting terminal block 50a or 50b is connected to the output terminal of the main current transformer (20a or 20b of FIG. 1) coupled to, for example, a three-phase high-voltage transmission line. The secondary side 54a "-54d" of the bar is connected to a line protection device such as a measuring instrument or a protection relay for measuring an electric quantity such as current or power of a transmission and distribution line.

Thus, when the current transformer assembly 60 is added to the conductor bars 54a to 54d of the common connection terminal block connected to the output line of the main current transformer coupled to the three-phase line, it is easy to visually identify whether the conductor bars 54a to 54d are connected. can do. That is, when the lines of the power system in which the main current transformers 20a or 20d are installed are energized, the light emitting diodes 62a to 62d of the current transformer assembly 60 emit light. On the other hand, when maintenance or replacement of various measuring instruments or line protection devices connected to the secondary side of the common connecting terminal block 50 is necessary, tighten the screws of the conductive common connecting bar 56 to tighten a pair of conductor bars 54a to 54d. Common connection must be made. In this case, the light emitting diodes 62a to 62d of the current transformer assembly 60 are turned off. When the operator confirms that the light emitting diode is turned off, and performs maintenance or replacement of various devices connected to the secondary terminal of the terminal block, the worker can perform safe work without causing damage to the main current transformer.

Using the common terminal block of the present invention, it is also possible to visually easily monitor the energization state of the power system to which the peripheral current transformer is connected. This can be done by making minor changes to the configuration of the common connection terminal block. That is, in FIG. 5, the positions of the current transformer assemblies 60a to 60d and the common connection bar 56 may be changed. This is the same as the case in which the current transformer assembly of FIG.

With this configuration, even though common connection of the conductor bars 54a to 54d is made with the common connecting bar 56, the current transformer assembly 60a to 60d has a current transformer assembly 60a in which current flows through the transmission and distribution line to which the peripheral current transformer is connected. Since the light emitting diodes 62a to 62d of ˜60d) emit light, it is possible to remotely monitor the energization state of the transmission and distribution line.

The device of the present invention as described above is not applicable only to the CT common terminal block. For example, it can be variously applied to power distribution boards, and for example, the same advantages can be obtained when applied to test terminals.

The present invention provides a current connection of a power system circuit by adding a current transformer assembly that provides a visual identification function to the cable connection part, that is, the common terminal block of the current transformer used to draw in and out of the switchboard, when the current transformer secondary line is connected to the power system. By making it easy for the operator to visually understand the condition, it is possible not only to prevent the operator's error but also to contribute to the stable power supply by preventing the accident of the power system caused by the opening of the main current transformer secondary line. By knowing and working correctly, you can prevent accidental physical accidents. In addition, it is easy to check the life and death of the track during the ceasefire operation at the common terminal of the current transformer.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art various modifications and changes of the present invention without departing from the spirit and scope of the present invention described in the claims below You can. Therefore, all changes which come within the meaning or range of equivalency of the claims are to be embraced within their scope.

Claims (5)

At least one terminal stand made of an insulating material is disposed, and at least one conductor bar is disposed on an upper surface of each terminal stand, and each terminal bar is screw-assembled to the terminal stand while each conductor bar is inserted into the current transformer assembly. The current transformer assembly includes: a current transformer for interpolating the current flowing through the conductor bars by interpolating the conductor bars; a light emitting device emitting light while a driving current is input; and a driving circuit receiving the output current from the current transformer to provide the driving current to the light emitting devices. The light emitting device and the driving circuit are exposed to the outside so that at least the light emitting device can be visually identified whether the light emitting device is assembled to the upper portion of the current transformer in a state of being assembled on a printed circuit board, And a conductive common connecting bar for connecting the conductor bars in common when necessary to be screwed to the terminal support while crossing the conductor bars in the set. The common connection terminal block of claim 1, wherein the current transformer assembly is assembled such that only the light emitting device is exposed to the outside of the case by embedding the printed circuit board and the current transformer in one case. The common connection terminal block of claim 1, wherein the current transformer assembly includes only the current transformer in a case, and the printed circuit board and the light emitting device mounted thereon are exposed to the outside of the case. The light emitting device of claim 1, wherein the light emitting device is a light emitting diode (LED), and the driving circuit supplies only a current amount necessary for the light emitting diode to operate stably among the output current amount of the current transformer to the light emitting diode, and the remaining current amount is the light emitting diode. A common connection terminal block, characterized in that configured to bypass so that it is not supplied to the diode. A plurality of common connection terminal blocks of any one of claims 1 to 4 are arranged inside the terminal box, and the primary terminal of the conductor bar of each common connection terminal block is connected to the output terminal of the main current transformer coupled to the three-phase high voltage transmission and distribution line. And a secondary terminal of the conductor bar is connected to a line protection device such as a measuring device or a protection relay for measuring an electric quantity such as current or power of the transmission and distribution line.