KR20080050716A - Vacuum fault interrupt transformer - Google Patents

Abstract

A VFI(Vacuum Fault Interrupt) transformer is provided to enhance efficiency of a mounting space by downsizing the vacuum fault interrupt transformer by collectively controlling a single phase and three phases through integrating a vacuum fault interrupter to the VFI transformer. A VFI transformer supplies power after transforming high-voltage power supplied from a power supply system into low-voltage power. A vacuum fault interrupter for interrupting the power supplied from the power supply system protrudes on a body of the VFI transformer. The vacuum fault interrupter interrupts and protects an overcurrent supplied to the VFI transformer with a Kyle vacuum interrupter instead of a fuse. The vacuum fault interrupter has a continuous current transfer ability. In case that a fault occurs when the vacuum fault interrupter is actuated, a trip free protects a mechanism in a running position.

Description

Ground Fault Interrupt transformer

The present invention relates to a ground transformer for supplying power after converting the special high-voltage power supplied from the power supply system to low pressure, the vacuum load cut-off switch for opening and closing the power input from the power supply system to the main body of the transformer By protruding, the size of the ground transformer can be significantly reduced, and accordingly, the ground transformer can be improved by minimizing the installation area of the ground transformer.

Typically, electric power generated from hydroelectric power, thermal power, or a nuclear power plant is transferred to the final consumer side of a home, office, factory, etc., and reaches the final consumer side via a substation and a transformer in an intermediate stage. The power generated at the power plant is typically supplied to the substation at a high pressure of 154 KV or 345 KV, which is then lowered back to a high voltage of typically 22.9 KV and supplied to the transformer just before the final consumer side, where the final It is converted to a voltage of 110V or 220V, which is a voltage suitable for use by the customer, and is supplied to the final customer.

Such a transformer includes a residential transformer installed in a pole and a transformer for underground distribution lines installed on the ground. Among these, the columnar transformer is relatively small in capacity, and thus is relatively small and light in weight, and is usually installed in a pole and the like to lower the high pressure from the substation to low pressure and supply it to the final customer side.

However, in crowded metropolitan areas, it is very dangerous to drag high voltage (22.9 KV) distribution lines from substations through electric poles in congested urban areas. It is a situation where electric power is supplied to the final consumer side through a transformer installed on the ground, that is, a ground transformer, while dragging the (distribution line).

On the other hand, conventionally, in order to supply power with 22.9 kV extra high voltage of 100 kW or more in the underground distribution line power supply system for supplying power to the underground, it is possible to supply electric power by installing one ground switch.

However, low-voltage (220 / 380V) power supply requires a separate ground breaker for every 4-6 ground transformers in the case of load density areas that are intentionally underground, such as underground processing lines or underground power supply in industrial and residential complex development areas. In the case of supplying power at low pressure in the branch line, a separate ground breaker must be installed for each ground transformer to be installed, which requires a lot of cost.

Ground switchgear is used for switching high voltages and switching loads during replacement or inspection. If a breakdown occurs between the switchgear and the switchgear, between the switchgear and the ground transformer, or in the power cable for the ground transformer supply, switch the load so that the ground breaker can receive power from another ground transformer, and check the ground transformer that has failed. After replacement, the power is supplied by supplying power or load switch.

Ground transformers used in underground distribution line power supply system are as follows: First, the installation cost for small-capacity power supply of less than 100 kW should not be more than the installation cost for large-capacity power supply above 100 kW. Improve the reliability of the power supply through proper operation of the power system to minimize power failure and power failure even when the power cable for transformer or ground transformer supply fails. Third, check for abnormality of ground transformer or power cable during power supply. In order to facilitate this, the efficiency of facility maintenance should be improved.

Conventional ground transformers require a small capacity low voltage (220 / 380V) power supply of less than 100 kW, the ground transformer and a separate ground breaker, respectively.

On the other hand, in order to supply large-capacity extra-high voltage (22.9 ㎸) power over 100 kW, only a ground switch is needed to supply power from the substation through the power supply system. More economical than supplied.

The conventional ground transformer is a transformer that is installed on the ground in the case of failing to supply electric power by installing a distribution line in the center of a city or a densely populated area in aesthetic or peripheral conditions, that is, when a pole transformer is not installed. It is protected by an enclosure of cuboids.

However, most ground transformer enclosures frequently injure the aesthetics of the city by indiscriminately attaching various promotional stickers or illegal advertisements.

Looking at the reason of the sticker to the transformer enclosure, the ground-mounted transformer enclosure is a rectangular shape (height 1.5m or less) is easy to put a sticker, the ground-mounted transformer enclosure is mainly used by people such as the city center or licensed It is located in frequent places, so the propaganda effect is very large.

However, a lot of illegal advertisements are attached to the ground transformer or ground switch exposed to pedestrians. This illegal flyer itself is not only aesthetically pleasing, but it can also be torn and fall off and disturb the periphery of the transformer.

In addition, since the size and the location of the above-mentioned ground transformer and the ground breaker interfere with the aesthetics of the downtown area, the ground transformer and the ground breaker have been recently constructed inside the building, but an attempt has been made to beautify the urban aesthetics. According to the rapid increase, the installation of a ground transformer and a ground switch in an expensive space is a waste of resources and a disadvantage of not properly utilizing the space.

The present invention has been made to solve the above problems, to provide a ground transformer to improve the space utilization by minimizing the installation space of the ground transformer by allowing the ground breaker to be installed / operated integrally to the ground transformer. The purpose is.

The above object is, in the ground transformer for supplying power after converting the special high-voltage power supplied from the power supply system to low pressure, the vacuum load cut-off switch for opening and closing the power input from the power supply system has a main body of the transformer It is achieved by a ground transformer, characterized in that protruding in the.

Hereinafter, the configuration of the present invention will be described.

The ground transformer is a vacuum load interrupter (VFI) (hereinafter referred to as a VFI breaker) installed in the main body, and is a combination with a distribution transformer.

The above vacuum load breaker switches off and protects the overcurrent supplied to the transformer with a Kyle vacuum breaker instead of a fuse, and the VFI breaker has a continuous current transfer capability and a breaking range that exceeds the standard fuse, and is broken by a resettable VFI breaker mechanism. Immediate service recovery is possible in the event of a current.

This eliminates the additional downtime and the cost of replacing the fuse, and trip-free protects the mechanism in the operating position if the VFI breaker goes into a fault condition when it is activated.

The VFI breaker is controlled by a three-phase circuit breaker control, which is a combination of time-current-curve (TCC), and the function of the trip occurs when a current higher than the set fault level is detected. By generating control to bypass the instantaneous trip, an artificial delay can be eliminated.

Tapped switching or voltage-free fittings are achieved by removing the load brake elbow, or by loading-busting the fuse or switch.

Therefore, the VFI breaker performs the interrupt injection function of the fault current, trips the trip trip of the load, and can also be used for the on / off switch.

At the same time, three phases can be operated and operated in a batch, and each phase can be opened and closed, that is, the on / off function during load is operated and operated as a single phase, thereby minimizing the trouble area and minimizing the outage time, thereby improving reliability. .

The VFI breaker is equipped with an electronic control unit for remote control, so that current control can be set remotely according to the environment, and the ground current can be sensed.

As described above, in the present invention, when the ground transformer and the ground breaker are integrally manufactured, the VFI breaker is introduced to allow the ground transformer to be integrally coupled to the ground transformer so that the single and three phases can be collectively controlled. Significantly reduced installation space can be used efficiently. Especially, the size of the large ground transformer installed in the downtown area is reduced so that the exterior of the downtown can be more beautifully trimmed. In the case of the ground transformer installed in the building, By being used to a minimum, the space utilization is improved to have an effect of achieving efficient space utilization.

Claims (1)

In the ground transformer for supplying power after converting the high voltage power supplied from the power supply system to low pressure, The ground transformer, characterized in that the vacuum load cut-off switch for opening and closing the power input from the power supply system protruding to the main body of the transformer.