Pre-installed American Box Type Substation

● Product Structure Characteristics

◆ The ZBW-12 Pre-installed American Box Type Substation has compact structure and small volume, which is only about 1/3~1.5 of that of domestic European box transformer with the same capacity, thus greatly reducing the floor space.

◆ The Substation adopt fully sealed and fully insulated structure, without insulation distance, and reliably protect personal safety.

◆High-voltage wiring can be used for both ring network and terminal, with flexible power supply mode and high reliability.

◆Excellent transformer performance: low loss, low noise and low temperature rise; Strong overload capacity, short circuit resistance and impact resistance.

◆Meet all kinds of low-voltage feed-out requirements, which can be selected according to the scheme or designed by yourself.

● Technical Parameters Table

● Fuse

The high voltage side of Pre-installed American Box Type Substation is provided with full range protection by series connection of backup protection fuse and plug-in fuse, which is simple in principle, economical and reliable; The backup protection fuse is an oil-immersed high-voltage current-limiting fuse with large breaking capacity. Only when the transformer fails internally, the plug-in fuse is equipped with a dual-sensitive fuse, which can provide double protection of current and temperature. After the dual-sensitive fuse is blown, the fuse core can be easily replaced on site.

● Structure and operation sequence

1. The layout

For the shape and structure of 10kV ZBW-12 Pre-installed American Box Type Substation, see Figure 2 and Figure 3. The oil tank is divided into two parts: the upper part is the high-voltage oil tank and the lower part is the transformer oil tank. The two parts are only electrically connected, but the oil is blocked. The schematic diagram is shown in Figure 1, in which "I" and "I" lines are loop network feeders, "ll" branches are transformer branches, and "V" is low-voltage output. Substation can be used in both ring network power supply system and terminal system, and the conversion is very convenient. The feed of the line and "lⅢ" branch is switched with the load switch of the ring network. At the same time, the incoming terminal of the high-voltage side of the transformer is equipped with backup protection fuses and plug-in fuses to protect the short-circuit fault and overload and overtemperature protection of the branch. At the same time, high-voltage display devices and lightning arresters can also be installed. The low-voltage end of the transformer is output after passing through a meter and a low-voltage circuit breaker.

Dimensions and Weight

2. The transformer

KEXR Pre-installed American Box Type Substation adopt the new S9 and S11 series three-phase oil flooded transformers have the advantages of low no-load loss, low temperature rise, low noise and low height. The no-load loss and load loss of the transformer are lower than those of the original S9 transformer, reaching the domestic advanced level at present. The transformer is of fully sealed structure, which effectively isolates the air pollution and insulation degradation caused by moisture. An air cushion of 40-90mm is left at the top of the oil tank, which can play the role of heat dissipation and cooling together with the corrugations of the oil tank shell, and can effectively reduce the internal pressure.

Dimensions and Weight

3. Backup Protection Fuse

It is connected in series with the plug-in fuse in the transformer branch (see R1 and R2 in Figure 2) to form a full-range protection fuse. It only blows when there is a short-circuit fault inside the substation, so the probability of blowing is very low. It is installed in the upper oil tank, and the oil tank needs to be opened if it is to be updated.

4. Plug-in Fuse

◆Its melting core has dual sensitivity (temperature and current), that is, it melts when the load side fails (overload or excessive temperature). Plug-IN fuse and backup protection fuse are used in series, which can protect the whole range from small current (several times in) to large current (several tens of kiloamperes), and the maximum breaking current is 50kA.

◆The reasonable matching of backup fuse and plug-in fuse directly affects the performance of the whole substation. See the following table for a part of the fuse selection guidelines in 10kV Pre-installed American Box Type Substation for reference only. NOTE: it is not suitable for other types of substations.

● Outline Dimension of Pre-installed American Box Type Substation