KR101211834B1 - Power distribution system - Google Patents

Abstract

The present invention provides a high voltage distribution unit for supplying a high voltage power; A transformer for converting the high voltage power of the high voltage distribution unit into a low voltage power source; And a low voltage distribution unit for supplying the low voltage power converted by the transformer, and the high voltage distribution unit, the transformer unit, and the low voltage distribution unit are disposed in one case.

Power Distribution, High Pressure, Low Pressure, Transformer, Underground, RMU

Description

Power Distribution System {POWER DISTRIBUTION SYSTEM}

The present invention relates to a power distribution system.

Underground power distribution system will develop in the direction of solving various requirements such as facility expansion and reduction of installation space / area in the process of new city development, eco-friendliness, convenient installation and maintenance, and safety of operation due to the increase of urban power. have.

1 shows a conventional general underground distribution system.

The underground distribution system shown is divided into three circuit switches (3L) or four circuit switches (4L) on a 22.9kV high-voltage distribution line to form a high-voltage distribution system.

The underground underground distribution system in Korea divides and branches the system by using the multi-circuit switch 110 composed of the three or four circuit switches with respect to the high voltage power supplied from the substation.

The high voltage consumer diverges from a single 3 or 4 circuit switch to provide a high voltage faucet, while the low voltage consumer uses a series π transformer alone installation method in which 4 to 7 transformers 130 are connected in series between two switches. It is configured to supply low voltage power by applying. That is, the high voltage power of the high voltage distribution system is converted to low voltage power through the transformer and applied to the low voltage distribution system. The low voltage distribution system has a distributor (not shown) for distribution.

The multi-circuit switch, the transformer, and the divider applied to the conventional underground distribution system are manufactured separately and each is individually installed.

2 shows a multi-circuit switch for a conventional underground distribution system.

The multi-circuit switch 110 is a switch having a common bus bar, three or more switches, as shown in Figure 2 is a four-circuit multi-circuit switch composed of three phases as shown in Figure 2 (incoming) according to the system configuration It is used as a switch, outgoing switch, transformer line switch, and other circuit connection switch.

3 shows a transformer applied to a conventional underground distribution system.

The transformer 130 is divided into a high voltage terminal portion 131 and a low voltage terminal portion 133, and the high voltage terminal portion is provided with two pairs of three-phase connection portions for drawing out high voltage lines.

FIG. 4 shows an underground low voltage distribution box, which is a distributor used for branching of a low voltage line drawn from a low voltage terminal portion of a conventional transformer secondary side.

In the conventional underground distribution system described above, the multi-circuit switchgear, the transformer, and the divider constituting the high voltage distribution system, the transformer, and the low voltage distribution system are each manufactured as individual devices, and have a structure that is separately installed.

These separately divided devices are interconnected by high and low voltage lines to supply power.

For example, the case of supplying the high pressure consumer with reference to FIG.

In the case of a three-circuit multi-circuit switch 110, a 1-circuit switch of the multi-circuit switch is connected to the power distribution system to the 22.9 kV distribution system on the transmission station side, and the two-circuit switch opens and closes the line connected to the high voltage consumer. To supply power to the system. Then, the remaining three circuit switch is connected to the next multi-circuit switch or other power distribution equipment of the distribution line. In the case of the low voltage system supplied to the low pressure consumer, the low voltage consumer receives the 380/220 V low voltage power generated at the secondary side of the transformer through a transformer 130 connected in series in the middle of a distribution line to which two multi-circuit switches are connected. Will be supplied to

On the other hand, the low-voltage power supply on the secondary side of the transformer is branched through the underground low-voltage distribution box of Figure 4 to supply to the plurality of low-voltage consumers.

The existing power distribution system type π type transformer alone installation method is a method of connecting 4 ~ 7 ground PAD transformers in series between two switches connected to the system. During maintenance, both ends of the multi-circuit switch (110a, 110b) connected to the low-voltage distribution system should be open. As a result, all other transformers connected together are powered down, resulting in power outages in a wide range of areas, and costly and time-consuming to recover with the latest uninterruptible methods. In addition, the installation of these individual devices is limited by the installation location and location in the modern urban environment. That is, for low-voltage distribution, each of the multi-circuit switchgear, transformer and divider of the underground distribution system must be installed alone, so at least three installation points are required, which causes environmental problems that damage the surrounding landscape.

In order to cope with the increase in power demand and concentration due to the high density of society, this problem is caused by the space constraints of installing each device individually, excessive cost, complaints about the installation of hate facilities, and maintenance costs. Many problems such as increase and deterioration of aesthetics are encountered. In particular, in the case of a transformer mainly placed on the ground, a fuse is installed inside the inflow transformer, and the fuse inside the transformer is blown when an unexpected accident occurs, and excessive maintenance time and costs are required until restarting. Can be. In addition, the conventional low-voltage distribution box simply applies a mechanical MCCB and uses a common N-phase, so that a ground fault cannot be detected when a ground fault occurs in a low-voltage line. In the event of an accident, the accident is likely to spread to other tracks diverged from the same distribution box. In summary, efficient management of multi-circuit switchgear, transformer, and divider which are individually installed is impossible.

The present invention is to provide a power distribution system capable of efficient management.

Technical problems to be achieved by the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned above will be clearly understood by those skilled in the art from the following description. Could be.

In order to achieve the above object, a distribution system according to the present invention includes a high voltage distribution unit for supplying high voltage power; A transformer for converting the high voltage power of the high voltage distribution unit into a low voltage power source; Including a low voltage distribution unit for supplying the low voltage power converted by the transformer, the high voltage distribution unit, the transformer unit and the low voltage distribution unit may be disposed in one case.

In this case, the high-voltage distribution unit may include a multi-circuit switch, in this case the multi-circuit switch may be a high-pressure gas load switch.

The low voltage distribution unit may include a divider.

The case may be provided with a common ground of the high voltage distribution unit, the transformer unit, and the low voltage distribution unit.

The transformer may be connected in parallel with the high voltage distribution unit.

As described above, the power distribution system according to the present invention can be efficiently managed by installing the high pressure distribution unit, the transformer unit, and the low pressure distribution unit which are individually installed in one case.

EMBODIMENT OF THE INVENTION Hereinafter, the power distribution system which concerns on this invention is demonstrated in detail with reference to drawings.

5 is a block diagram of a power distribution system according to an embodiment of the present invention.

The illustrated distribution system 200 supplies a high voltage distribution unit 210 for supplying a high voltage power, a transformer 230 for transforming the high voltage power of the high voltage distribution unit into a low voltage power source, and a low voltage power converted from the transformer unit. The low voltage distribution unit 250 and the like, and the high voltage distribution unit, the transformer unit and the low pressure distribution unit are disposed in one case 270.

The high voltage distribution unit 210 receives a high voltage power from a power transmission station or a predetermined multi-circuit switch and supplies it to another circuit, a high voltage consumer, and the like. The high-voltage distribution unit is configured to include a multi-circuit switch, such as three or four circuits, specifically, it is preferable that the high-pressure gas load switch (RMU, Ring Main Units).

The transformer 230 is an element for converting the high voltage power branched and supplied from the high voltage distribution unit into a low voltage power required by a low voltage consumer, and includes a transformer capable of stepping down generally.

The transformer unit is connected to at least two multi-circuit switch connected to the low voltage distribution unit side of the multi-circuit switch of the high-voltage distribution unit to convert the high-voltage power of the multi-circuit switch to a low-voltage power supply to the low-voltage consumer. The transformer may be connected in series with respect to the multi-circuit switch. However, when a problem such as a failure occurs as described above, the transformer is required to be opened and performed, so that the transformers are connected in parallel.

The low voltage distribution unit 250 supplies the low voltage power converted by the transformer to a low voltage consumer, and the like, and specifically, includes a divider connected to the secondary side, which is the low voltage output side of the transformer. The low voltage distribution unit branches the low voltage power converted from the transformer through the distributor to supply each low voltage consumer.

As described above, the high pressure distribution unit, the substation part, and the low pressure distribution unit are disposed in one case 270. The case may be manufactured in the shape of a conventional switchgear or distribution box, and may be manufactured differently. In the power distribution system according to the present embodiment, since the high voltage distribution unit, the substation unit, and the low voltage distribution unit are installed in a common case, by including common ground for the three elements, the waste of resources required for the grounding process is prevented. At the same time, miniaturization is desirable. The common ground may be formed outside and inside the case.

In addition, the power distribution system according to the present embodiment may further include a monitoring unit for detecting and displaying the state of the high voltage distribution unit, the transformer unit and the low voltage distribution unit. In the past, since the high voltage distribution unit, the transformer unit, and the low voltage distribution unit were formed separately, there was a difficulty in integrated monitoring. Even in the case of monitoring each, the cost is increased because an element for extracting each monitoring data must be installed in each element. However, according to the present embodiment, it is possible to monitor all of the high pressure distribution unit, the transformer unit, and the low pressure distribution unit at one time through the integrated monitoring unit. The monitoring unit is preferably formed in a position that can be confirmed by the user in the case. If it is necessary to monitor in the central management unit spaced apart from the case, the high voltage distribution unit, the transformer unit, and the low voltage distribution unit to extract the status signal generated by the state management unit including a communication unit for transmitting to the central management unit; It may be.

In summary, the power distribution system according to the present embodiment integrates and installs the high voltage distribution unit, the transformer unit, and the low voltage distribution unit, which were formed separately, in one case, thereby reducing the reliability of the system and increasing the installation location. Increasing costs and disrupting the aesthetics of the city caused by indiscriminate installation of power equipment can be solved, and functions such as more stable and efficient monitoring, diagnosis, protection, communication, and control can be provided, resulting in efficient management. .

6 is a cross-sectional view showing in more detail the power distribution system according to an embodiment of the present invention.

The illustrated power distribution system is configured as a single power distribution system by installing the devices that were conventionally installed and operated in one case 270, and can manage the devices individually managed in the conventional power distribution system. Specifically, RMU (Ring Main Units), which is a sensor-embedded high-pressure gas load switch, was applied to the high-voltage distribution unit 210, and a transformer capable of connecting the high-voltage unit to the dead end connection member was employed as the transformer unit 230. An LV panel (low voltage panel) was connected directly to the secondary side of the transformer through the low voltage distribution unit 250 to constitute a single case. In addition, the case is not a forced cooling method applied in the existing outdoor switchgear, such as a natural cooling method for discharging the heat generated inside the case to the outside by including a flow path of air optimized through the optimal design for the heat flow Applicable

7 is a circuit diagram of a power distribution system according to an embodiment of the present invention.

The illustrated distribution system includes a large voltage distribution unit (210) RMU, a transformer 230, a transformer and a low voltage distribution unit (250) LV panel.

The high voltage distribution unit 210 has two LBS (Load Break Switch) switches connected to a line of a distribution system, and is composed of a vacuum circuit breaker (VCB) used as a load to be supplied to a customer. Each of the LBS and the VCB has a structure in which a ground switch is attached, thereby maximizing safety during maintenance of the distribution system and the load stage.

The dead end connection type transformer, which is the transformer 230, is a three-phase four-wire Y-connected transformer connected to the high voltage distribution unit 210 and the low voltage distribution unit 250 in the distribution system.

The LV panel, which is the low voltage distribution unit 250, is equipped with an electronic ACB (air circuit breaker) as a main breaker, and an electronic molded case circuit breaker (MCBB) is installed as a branch breaker on the load side. Low-voltage power distribution unit is applied to the electronic breaker (ACB, MCCB), it is possible to selectively block and ground fault protection through communication with each other.

The RMU is desirable to maximize the measurement accuracy by applying an electronic voltage / current transformer of more than 1.0 class, it is possible to monitor the operating state of the drive unit by applying a Hall sensor to the mechanism driving motor and the input trip coil. .

In addition, a conventional gas density sensor and a PD (Partial Discharge) sensor capable of detecting partial discharge may be attached to the tank to constantly monitor the gas state and partial discharge in the tank.

The RMU is the high voltage distribution unit of the distribution station. The left and right LBS are connected to the underground distribution line, and the high voltage power is supplied to the transformer of the distribution system through the central VCB. In addition, since the RMU applies a VCB breaker to the load supply stage, the RMU can be quickly detached at the time of an accident in the load stage compared to the case of applying a conventional multi-circuit switch, thereby increasing the stability of the distribution line.

 In order to facilitate the connection of the high and low voltage cables, it is preferable that both the dead end connection bushing and the low voltage bushing are mounted on the upper part of the transformer exterior to facilitate installation and maintenance. In addition to the analog type oil temperature and oil level gauge, the transformer is equipped with oil temperature and oil level sensor to monitor the condition of the transformer at all times.

In addition, by removing a fuse installed in the transformer, such as CL-Fuse, Bay-O-Net Fuse installed in the transformer of the conventional underground distribution system, it is possible to minimize the breakdown portion of the transformer. This can be done by replacing the transformer protection device mounted inside the transformer with the VCB breaker of the transformer primary RMU and the electronic ACB on the secondary side, thereby minimizing the inspection and maintenance points of the transformer. That is, the VCB breaker of the high voltage distribution unit and the ACB breaker of the low voltage distribution unit replace the stabilizer of the transformer unit. Such a configuration can be achieved by integrating a single case.

The LV panel directly supplies the low voltage power supplied from the transformer secondary side to the low voltage consumer by applying the electronic ACB as the parking breaker and the electronic MCCB as the branch breaker. The LV panel has mutual protection coordination between the electronically driven ACB and the MCCB, and is capable of selectively blocking through communication with each other. In addition, by applying an electronic MCCB having a ground fault detection function, ground fault protection is possible for each load of the MCCB.

On the other hand, the power distribution system may further include a monitoring unit for monitoring the status of each element as described above, it may also include a communication unit for transmitting a status signal for monitoring in the central management unit spaced from the power distribution system.

The central management unit monitors and controls through a communication control unit (CCU), which is a communication control module, and such monitoring and control can be performed between a plurality of power distribution systems, in which case a certain power distribution system serves as a relay or a central management unit. Will be performed.

8 is an illustration of a distribution system when the distribution system according to an embodiment of the present invention is applied.

In the schematic diagram shown above, the high pressure supply stage is protected by the RMU VCB breaker, and the low pressure supply stage is individually protected by the breakers (ACB, MCCB) of the low voltage distribution section, thereby maximizing the reliability and stability of the distribution system.

In addition, the power distribution system may be equipped with an automatic fire extinguishing unit (not shown) to automatically extinguish fire when an abnormal condition such as an internal fire occurs. In addition, the immersion level sensor (not shown) can also be installed to monitor whether the flooding due to natural disasters. The automatic fire extinguishing unit and the submerged level sensor may be installed in the case of the power distribution system, and may be installed in at least one of the high pressure distribution unit, the substation part, and the low pressure substation part.

The power distribution system according to an embodiment of the present invention aggregates the components of the underground power distribution system and implements a single product, thereby reducing installation space and cost, and connecting and disconnecting the power distribution line and the power distribution transformer by the RMU. It is possible to automatically separate from the system by the RMU in the case of a transformer unit accident to prevent the spread to the distribution system in the event of an accident of the transformer and low-voltage unit. As such, maintenance can be performed by separating and removing only the target transformer alone during maintenance of the low voltage distribution section supplied through the transformer in the distribution line, thereby minimizing the blackout period and improving the reliability of the system due to the expansion of the protection function. Will be improved. The low voltage line on the secondary side of the transformer part applies electronic ACB as main breaker, and electronic MCCB as branch breaker to control power supply for each load, and electronic breaker enables measurement and control through mutual communication. Done. By applying the main breaker and branch breaker in this way, it is possible to strengthen the protection function in case of accident of low voltage distribution. The low voltage power supply from the low voltage distribution board supplies the N phase to each branch circuit breaker MCCB and monitors the current of the N phase, so that the load generated in the event of a ground fault can be immediately identified and shut off, and thus the occurrence of a ground fault. Prevention, and only the generating part can be selectively separated from the system, thereby minimizing the blackout period, thereby greatly improving the power supply reliability of the system.

In addition, if four or more switches of the RMU, which are high voltage inlets, are applied as shown in FIG. 8, in addition to the two switches connected to the system and one switch supplied to the transformer, one or more switches may be supplied to the high voltage consumer. The installation of one power distribution system enables the supply of power to both high and low pressure consumers. In this case, three or more independent devices, such as a multi-circuit switch for high pressure supply, a transformer for low pressure supply, and a low voltage divider for branching a low voltage line, are applied, thus securing installation space, increasing construction cost, and maintaining Although a problem such as an increase in cost has occurred, when the power distribution system of the present invention is applied, both high and low pressures can be supplied through a small power distribution system, so space is easily secured, and construction costs are minimized and maintenance is required. It becomes easy.

On the other hand, while the technical spirit of the present invention has been described in detail according to the above preferred embodiment, it should be noted that the above embodiment is for the purpose of description and not for the limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

1 is a conventional general underground distribution system.

2 is a view showing a multi-circuit switch applied to a conventional underground distribution system.

3 is a view showing a transformer applied to the conventional underground distribution system.

FIG. 4 is a diagram illustrating an underground low voltage distribution box which is a distributor used for branching of a low voltage line drawn from a low voltage terminal portion of a conventional transformer secondary side; FIG.

5 is a block diagram of a power distribution system according to an embodiment of the present invention.

6 is a cross-sectional view showing in more detail the power distribution system according to an embodiment of the present invention.

7 is a circuit diagram of a power distribution system according to an embodiment of the present invention.

8 is a distribution diagram when a distribution system according to an embodiment of the present invention is applied.

Description of the Related Art [0002]

210.High voltage distribution 230.Transformer

250.Low voltage switchboard 270 case

Claims (10)

A high voltage distribution unit for supplying high voltage power; A transformer for converting the high voltage power of the high voltage distribution unit into a low voltage power source; A low voltage distribution unit supplying the low voltage power converted by the transformer unit; And It includes a case in which the high pressure distribution unit, the transformer unit and the low pressure distribution unit is installed, The case is provided with a monitoring unit for detecting and displaying the state of the high voltage distribution unit, the transformer unit and the low voltage distribution unit, and a communication unit for transmitting the status signals of the high voltage distribution unit, transformer and low voltage distribution unit to the central management unit, The high voltage distribution unit includes a VCB (Vacuum Circuit Breaker) and a multi-circuit switch connected to the transformer unit, The low voltage distribution unit includes an ACB (air circuit breaker) connected to the transformer unit and a divider, And the transformer unit is connected in parallel with the high voltage distribution unit. The method of claim 1, The multi-circuit switch is a power distribution system comprising a high-pressure gas load switch. delete delete delete delete The method of claim 1, And a case in which the air flow path for cooling is formed. delete The method of claim 1, In the case of the power distribution system further includes an automatic fire extinguishing unit that operates when an abnormal condition occurs. The method of claim 1, And a submersion level sensor for detecting a submersion degree inside the case.

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