JP2503385B2 - Substation equipment for distribution - Google Patents

Description

The present invention relates to distribution substation equipment.

The current power system is shown in FIG. That is, A
220-500KV ultra-high voltage system, 1 220-500KV / 66-154
KV primary substation, 2 66-154KV transmission line, 3 66-154KV
/ 6.6-22KV distribution substation, 4 is 6.6-22KV distribution line, 5 is
6.6 to 22KV power receiving customer, 6 is a 6.6 to 22KV / 100 to 400V pole pole transformer, and 7 is a lighting customer.

In such a power system, in addition to the parallel capacitor 8 as shown in FIG. 2 of the related art, there are many power capacitors 9 installed in the customers 5 and 7, and even if the load decreases at midnight, the power capacitors are not used. Since there are few cases where the capacitor 9 is disconnected, there is a problem that the amount of advance for the phase advance increases. Therefore, in order to compensate for this, a shunt reactor 10 is installed in the primary substation 1 so that the reactive power flowing into the ultra-high voltage system A is reduced.

By the way, in such a shunt reactor 10, the shunt reactors 11 and 12 are installed on the distribution substation 3 side as shown by the broken line in FIG. 2 and FIG. 3 rather than installed on the primary substation 1 side. Since the amount of reactive power flowing through the transmission line 2 is smaller, it is more advantageous in reducing transmission loss. However, when installed in the distribution substation 3, the capacity of the shunt reactors 11 and 12 is relatively small, 5 to 20 MVA, and the capacity of the primary substation 1 is 20 to 20 MVA.
The cost per capacity is higher than that of a large capacity of 120 MVA. In addition, a space and a site for switchgear are newly required in the distribution substation 3. It is especially difficult to secure a site for the substation because it is necessary to install a shunt reactor in the center of the city with a high density of cables and a high population density. Therefore, it is difficult to implement the distribution substation 3, and the shunt reactors 11 and 12 are rarely installed in the distribution substation 3 in the current power system.

Therefore, an object of the present invention is to provide a distribution substation facility that can reduce transmission loss and can easily install a shunt reactor on the distribution substation side without increasing the installation space.

An embodiment of the present invention is shown in FIGS. That is, FIG. 4 shows a 3-phase shunt reactor transformer,
Main windings 16a to 16c are attached to an iron core leg 15 having a gap 14 of the iron core 13.
And the secondary windings 17a to 17c for distribution voltage are added,
It is designed to reduce the turns ratio to 66-154KV / 3.3-22KV. Fig. 5 shows an equivalent circuit of this shunt reactor transformer TrR, which reduces the reactive power by making the lag component of the shunt reactor transformer TrR correspond to the lead component of the power capacitor 9 and transforms it. Thus, the transformer in the distribution substation 3 can be substituted.

FIG. 6 shows the power system of the distribution substation equipment in the distribution substation 3. The branch reactor transformer TrR is shown in FIG.
Is applied to at least one of the distribution transformer groups 18 instead of the transformers, and a breaker 21a capable of appropriately disconnecting this shunt reactor transformer TrR is provided in the shunt reactor transformer TrR. . 19a and 19b are shunt reactor transformers Tr
A distribution transformer that constitutes the distribution transformer group together with R, 20 is a disconnecting switch at each location, and 21 is a circuit breaker at each location.

In this way, the shunt reactor transformer that also functions as a transformer
By installing the TrR in place of the conventional transformer as shown in Fig. 6, it is clear from the comparison with Fig. 3 that the disconnector is installed.
20, the shunt reactor wiring equipment including the electric circuit elements such as the circuit breaker 21 is omitted, the equipment is simplified, and the site or building of the distribution substation 3 is not newly added and the conventional distribution It is possible to supply the lagging reactive power at the distribution substation 3 at the same site and equipment cost as the power transformer. Therefore, the reactive power can be reasonably balanced in the entire system, and the transmission loss in the transmission line can be reduced. Furthermore, when the phase reactive reactive power on the load side decreases and the phase reactive reactive power due to the shunt reactor transformer TrR becomes unnecessary, the shunt reactor transformer TrR is disconnected by the disconnecting means to always provide the phase delay reactive power. Electricity is not consumed by the shunt reactor transformer TrR, which is convenient for system operation.

INDUSTRIAL APPLICABILITY As described above, the distribution substation equipment of the present invention is a shunt reactor transformer that also functions as a transformer formed by winding a main winding and a secondary winding for distribution voltage around an iron core leg having a gap. Since it is at least one of the distribution transformer group and the disconnecting means for separating the shunt reactor transformer is provided, the shunt reactor transformer is installed in the distribution substation without increasing the space compared with the conventional one. It is possible to simplify the equipment of the distribution substation, further reduce the transmission loss, and it is possible to disconnect it properly when the lagging reactive power is unnecessary, which is advantageous. .

[Brief description of drawings]

Fig. 1 is the current power system diagram, Fig. 2 is a detailed system diagram showing a part of it, and Fig. 3 is the system diagram of the distribution substation.
FIG. 4 is a sectional view of a shunt reactor according to an embodiment of the present invention, FIG. 5 is an equivalent circuit diagram thereof, and FIG. 6 is a system diagram of distribution substation equipment. 17a to 17c …… Secondary winding, 18 …… Distribution transformer group, TrR…
… Shunt reactor transformer

Claims (1)

(57) [Claims] 1. A distribution transformer group including at least one shunt reactor transformer also having a transformer function, which is formed by winding a main winding and a secondary winding for distribution voltage on an iron core leg having a gap. , A distribution substation facility comprising a circuit breaker for disconnecting the shunt reactor transformer when the lagging reactive power is no longer needed.