CN220710866U

CN220710866U - Transformer substation

Info

Publication number: CN220710866U
Application number: CN202322250126.1U
Authority: CN
Inventors: 王晓欢; 徐冉; 王平; 曹智; 陈清; 梁昕
Original assignee: Shenzhen Power Supply Planning Design Institute Co ltd
Current assignee: Shenzhen Power Supply Planning Design Institute Co ltd
Priority date: 2023-08-18
Filing date: 2023-08-18
Publication date: 2024-04-02
Anticipated expiration: 2033-08-18

Abstract

The utility model discloses a transformer substation, comprising: four main transformers, each having 220kV outlet terminal, 110kV outlet terminal, first 10kV outlet terminal and second 10kV outlet terminal; 220kV buses are connected with 220kV outlet ends of each main transformer; 110kV buses are connected with 110kV outlet ends of each main transformer; the 10kV bus adopts a single bus segment eight-section bus annular wiring mode, the 10kV bus is divided into eight sections of 10kV sub-buses, the eight sections of 10kV sub-buses are connected with four first 10kV wire outlet ends and four second 10kV wire outlet ends in one-to-one correspondence, and each section of 10kV sub-bus is provided with ten outgoing wires. The transformer substation provided by the embodiment of the utility model can improve the direct distribution capacity of the low-voltage side, improve the equipment utilization rate, reduce the transformer substation distribution point of the regional power grid, reduce the power grid investment, release the land resource, improve the power grid planning flexibility and accelerate the engineering construction progress.

Description

Transformer substation

Technical Field

The utility model relates to the technical field of power equipment, in particular to a transformer substation.

Background

Because the electric power demand is rapidly increased, the distribution difficulty of the transformer substation is increased under the restriction of land resources, the development space and the land resources of the economically developed city are seriously insufficient, the contradiction between a large number of distribution points of the transformer substation and the scarcity of the land resources is increasingly prominent, and more distribution points are difficult to realize in the special electric power planning. Because of the difficulty of site selection and site distribution, it is not easy to select a proper land from the planning level for the transformer substation, so that a new phenomenon occurs in site selection of the transformer substation, namely that the 220kV transformer substation and the 110kV transformer substation are located in the same land block (hereinafter referred to as the same site). With the development of cities, the total power load and the density are continuously increased, the 500kV power grid is continuously strengthened, the mode of fragmented power supply taking a 500kV transformer substation as a center is gradually realized, and the 220kV power grid is functionally converted from power transmission to power distribution.

The existing scheme is that one station site builds a transformer substation, and a 220kV transformer substation and a 110kV transformer substation are built in the same land block for site selection of the 220kV transformer substation and the 110kV transformer substation. The scale and wiring modes of 220kV and 110kV substations are as follows:

commonly used 220/110/10kV transformer substation: four 240 megavolt-amperes (MVA) are adopted in the final stage, the capacity ratio of the transformer is 240:240:80MVA, thirty times of 10kV final-stage outgoing lines are respectively formed by ten times of main transformer belts #1 to #3, single bus sectional wiring is adopted on the 10kV side, and the 10kV side of the main transformer #4 is used as a unit wiring without load. Three 63MVA main transformers are adopted in the final stage of the 110/10kV transformer substation, forty-eight lines are output in the final stage of 10kV, sixteen lines are output in each main transformer, and a single bus is adopted for sectional wiring on the 10kV side. A220 kV transformer substation and a 110kV transformer substation 10kV outgoing line totally count seventy-eight loops, so that a general power consumption loop is required to be built in a region with eighty loops, namely two power transmission and transformation projects are required to be built in the 220kV transformer substation and the 110kV transformer substation, and the construction mode of the infrastructure mainly has the following defects:

1. the area of the two substations is overlarge, the investment of the power grid is overlarge, the construction period is long, and waste is generated in a high-voltage outgoing corridor.

2. Four main transformers of 240MVA of the 220kV transformer substation, three main transformers of 63MVA of the 110kV transformer substation are equivalent to seven main transformers, and only seventy-eight 10kV outgoing lines are taken, so that great waste of main transformer capacity can be caused.

3. If the construction condition of the 220kV site of the site selection point is good, but the 110kV site is difficult to implement, or the construction condition of the 110kV site is good, but the 220kV site is difficult to implement, the power grid planning of the site selection point is not flexible enough.

Disclosure of Invention

The present utility model aims to solve at least one of the technical problems existing in the prior art. Therefore, the utility model provides the transformer substation, which can improve the direct distribution capacity of the low-voltage side, improve the equipment utilization rate, reduce the transformer substation distribution point of the regional power grid, reduce the power grid investment, release the land resources, improve the power grid planning flexibility and accelerate the engineering construction progress.

The transformer substation according to the embodiment of the utility model comprises:

four main transformers, each main transformer is provided with a 220kV wire outlet end, a 110kV wire outlet end, a first 10kV wire outlet end and a second 10kV wire outlet end;

a 220kV bus connected with the 220kV outlet end of each main transformer;

a 110kV bus connected with the 110kV outlet end of each main transformer;

the 10kV bus adopts a single bus sectioning eight-section bus annular wiring mode, the 10kV bus is divided into eight sections of 10kV sub-buses, the eight sections of 10kV sub-buses are in one-to-one correspondence with four first 10kV wire outlet ends and four second 10kV wire outlet ends, and each section of 10kV sub-bus is provided with ten outgoing wires.

The transformer substation provided by the embodiment of the utility model has at least the following beneficial effects:

by dividing the low-voltage side of four main transformers into two wire outlets, dividing the 10kV buses into eight sections of 10kV sub buses by adopting a single bus sectioning eight-section bus annular wiring mode, wherein the eight sections of 10kV sub buses are connected with the eight low-voltage side wire outlets in a one-to-one correspondence manner, namely four first 10kV wire outlets and four second 10kV wire outlets, each section of 10kV sub bus is provided with ten wire outlets, the four main transformers can be provided with eighty-four loads, and compared with the traditional transformer substation with one 220kV transformer substation and seven main transformers with seventy-eight loads, the transformer substation provided by the embodiment of the utility model can improve the direct distribution capacity of the low-voltage side, improve the utilization rate of equipment, only one transformer substation needs to be built to replace one 220kV transformer substation and one 110kV transformer substation, reduce the distribution point of a regional power grid, reduce the investment of the power grid, improve the power grid project and speed and increase the planning flexibility.

According to some embodiments of the utility model, each of the main transformers is a split winding transformer having a first high voltage winding connected to the 220kV bus, a second high voltage winding connected to the 110kV bus, and a double split low voltage winding each connected to one of the 10kV sub-buses.

According to some embodiments of the utility model, the low voltage winding of each split low voltage winding is provided with a low voltage bushing.

According to some embodiments of the utility model, each of the main transformers is a high impedance transformer.

According to some embodiments of the utility model, each main transformer is equipped with reactive compensation means.

According to some embodiments of the utility model, the reactive compensation device is a capacitive reactance compensation device.

According to some embodiments of the utility model, the 220kV bus and the 110kV bus are both connected in a double-bus double-section mode.

According to some embodiments of the utility model, the 220kV busbar has eight-turn wires, the 110kV busbar has fourteen-turn wires, the 220kV side and 110kV side of each main transformer have a capacity of 240 megavolt-amperes, the 10kV side has a capacity of 120 megavolt-amperes, and the capacitive reactance compensation device employs seven 8 megavoltage capacitor banks and two 10 megavoltage reactor banks.

Additional aspects and advantages of the utility model will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model.

Drawings

The utility model is further described with reference to the accompanying drawings and examples, in which:

fig. 1 is a schematic diagram of a 220kV substation wiring in the prior art;

fig. 2 is a schematic diagram of a wiring of a 110kV substation in the prior art;

fig. 3 is a schematic diagram of the wiring of a substation according to an embodiment of the present utility model.

Reference numerals:

a main transformer 100;

220kV bus 200;

110kV bus 300;

10kV busbar 400.

Detailed Description

Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the utility model.

In the description of the present utility model, it should be understood that the direction or positional relationship indicated with respect to the description of the orientation, such as up, down, etc., is based on the direction or positional relationship shown in the drawings, is merely for convenience of describing the present utility model and simplifying the description, and does not indicate or imply that the apparatus or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

In the description of the present utility model, plural means two or more. The description of the first and second is for the purpose of distinguishing between technical features only and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present utility model, unless explicitly defined otherwise, terms such as arrangement, installation, connection, etc. should be construed broadly and the specific meaning of the terms in the present utility model can be reasonably determined by a person skilled in the art in combination with the specific contents of the technical scheme.

In order to better illustrate the advantages of the transformer substation according to the embodiment of the present utility model, a brief description of the transformer substation wiring method in the prior art is first made with reference to fig. 1 and 2. Fig. 1 is a schematic diagram of a 220kV substation in the prior art, and fig. 2 is a schematic diagram of a 110kV substation in the prior art.

Referring to fig. 1, four 240 MVAs are adopted in the final stage of the existing 220kV transformer substation, the capacity ratio of the transformer is 240:240:80MVA, ten circuits are respectively carried out by #1 to #3 main transformer in the final 10kV phase, a single bus segment is adopted on the 10kV side, and the 10kV side of the #4 main transformer is used as a unit wiring without load.

Referring to fig. 2, three main transformers of 63MVA are adopted in the final stage of the existing 110kV transformer substation, forty-eight main transformers are adopted as final-stage outgoing lines of 10kV, sixteen outgoing lines are respectively carried out on each main transformer, and single bus sectional wiring is adopted on the 10kV side.

A220 kV transformer substation and a 110kV transformer substation 10kV outgoing line totally count seventy-eight loops, so that a general power consumption loop is required to be built in a region with eighty loops, namely two power transmission and transformation projects are required to be built in the 220kV transformer substation and the 110kV transformer substation, and the construction mode of the infrastructure mainly has the following defects:

Based on the above, the embodiment of the utility model provides a transformer substation, which can improve the direct-distribution capacity of a low-voltage side, improve the utilization rate of equipment, replace a 220kV transformer substation and a 110kV transformer substation by only building one transformer substation, reduce the transformer substation distribution point of a regional power grid, reduce the power grid investment, release the land resource, improve the power grid planning flexibility and accelerate the engineering construction progress.

The substation according to an embodiment of the present utility model will be clearly and completely described with reference to fig. 1 to 3, and it is obvious that the embodiments described below are some, but not all, embodiments of the present utility model.

The transformer substation according to the embodiment of the utility model comprises four main transformers 100, 220kV buses 200, 110kV buses 300 and 10kV buses 400.

Four main transformers 100, each main transformer 100 having 220kV outlet terminal, 110kV outlet terminal, first 10kV outlet terminal and second 10kV outlet terminal;

220kV bus 200 connected with 220kV outlet end of each main transformer 100;

110kV bus 300 connected with 110kV outlet end of each main transformer 100;

the 10kV bus 400 adopts a single bus segment eight-section bus annular wiring mode, the 10kV bus 400 is divided into eight sections of 10kV sub-buses, the eight sections of 10kV sub-buses are connected with four first 10kV wire outlet ends and four second 10kV wire outlet ends in one-to-one correspondence, and each section of 10kV sub-bus is provided with ten outgoing wires.

The direct distribution capacity of the low-voltage side is directly influenced by the 10kV outgoing lines, and seventy-eight times of the 10kV outgoing lines of the 220kV transformer substation and the 110kV transformer substation are counted, so that the transformer substation considering the improvement of the low-voltage direct distribution capacity has the power supply capacity of the two transformer substations, and the 10kV outgoing lines of the transformer substation are considered according to eighty-eight times. The 10kV buses 400 adopt a single-bus-section eight-section bus annular wiring mode, the 10kV buses 400 are divided into eight sections of 10kV sub buses, each main transformer 100 is provided with two sections of 10kV sub buses, each section of 10kV sub bus is provided with ten outgoing lines, and four main transformers 100 are provided with eight sections of 10kV sub buses, and the total of eighty outgoing lines.

Seven main transformers 100 of a traditional 220kV transformer substation and a 110kV transformer substation can only carry seventy-eight back loads, and four main transformers 100 of the transformer substation in the embodiment of the utility model can carry eighty back loads, so that the direct distribution capacity of a low-voltage side is improved, the equipment utilization rate is also improved, only one transformer substation needs to be built to replace one 220kV transformer substation and one 110kV transformer substation, transformer substation distribution points of regional power grids can be reduced, power grid investment is reduced, land resources are released, power grid planning flexibility is improved, and engineering construction progress is accelerated.

According to the transformer substation provided by the embodiment of the utility model, the low-voltage side of the four main transformers 100 is divided into two wire outlets, the 10kV buses 400 are divided into eight sections of 10kV sub buses by adopting a single bus subsection eight-section bus annular wiring mode, the eight sections of 10kV sub buses are connected with the eight low-voltage side wire outlets in a one-to-one correspondence manner, namely four first 10kV wire outlets and four second 10kV wire outlets, each section of 10kV sub bus is provided with ten wire outlets, the four main transformers 100 can be provided with eighty-four loads, and compared with the traditional 220kV transformer substation and a 110kV transformer substation, the transformer substation provided by the embodiment of the utility model can improve the direct distribution capacity of the low-voltage side, improve the equipment utilization rate, only one transformer substation can replace one 220kV transformer substation and one 110kV transformer substation, reduce the distribution point of a regional power grid, reduce the investment of the power grid, release the land resources, improve the planning flexibility of the power grid, and accelerate the project construction progress.

In some embodiments of the utility model, referring to fig. 3, each main transformer 100 employs a split winding transformer having a first high voltage winding connected to 220kV bus 200, a second high voltage winding connected to 110kV bus 300, and a double split low voltage winding each connected to one 10kV sub-bus.

The main transformer 100 low-side outlet branch has two main schemes, first: the low voltage side of the main transformer 100 is provided with split windings, i.e. the low voltage side of the main transformer 100 is split inside the transformer. Second,: the low-voltage side single coil of the main transformer 100 is divided into two branches through copper bar lap joints after the low-voltage outgoing line of the main transformer 100. Because the second scheme is branched outside the main transformer 100, not only the charged distance between the copper bars is considered, but also a certain space is provided, which is not as simple as the first scheme. In addition, split windings are arranged in the main transformer 100, double-branch loop current is easy to control, load distribution is average, scheme II load distribution is uneven, and loop current is not easy to control. It is thus contemplated that each main transformer 100 employs split winding transformers.

In some embodiments of the utility model, the low voltage winding of each split low voltage winding is provided with a low voltage bushing. The low-voltage bushing is used for guiding the low-voltage lead out of the oil tank and is an insulating bushing, and the low-voltage bushing is used for insulating the lead from the ground and plays a role of fixing the lead. The number of the low-voltage bushings is six, one low-voltage winding corresponds to three low-voltage bushings of three phases, and one double-split low-voltage winding corresponds to six low-voltage bushings.

In some embodiments of the present utility model, each main transformer 100 employs a high impedance transformer. The main transformer 100 of the 220kV transformer substation generally has a medium-impedance transformer and a high-impedance transformer, and the two transformers have different costs due to different impedances. If the short-circuit current is not out of limits (a 10kV short-circuit current of 31.5kA in the embodiment of the utility model), a medium-impedance transformer can be selected. According to the national standard medium impedance transformer, the impedance values are Uk 1-2=14%, uk 1-3=35%, uk 2-3=21%, and the trial calculation short circuit currents are shown in table 1:

TABLE 1 short circuit current

The three-phase short-circuit current and the two-phase short-circuit current at the 10kV side are both greater than 31.5kA and do not meet the requirements, so that in the situation, a medium-impedance transformer and a current-limiting reactor are adopted, the short-circuit current is limited by two schemes of a high-impedance transformer and a current-limiting reactor, wherein the current-limiting reactor is connected in series between the low-voltage side of the medium-impedance transformer and the 10kV bus 400.

The medium impedance value is uk1-2=14%, uk1-3=35%, uk2-3=21%, the high impedance value is uk1-2=14%, uk1-3=64%, uk2-3=50% of the transformer, the current limiting reactor is 4000A, and the reactance rate is 10%. The short circuit current is calculated as in table 2:

table 2 short circuit current comparison table

As can be seen from table 4, the 10kV side three-phase short circuit current and the two-phase short circuit current both meet the requirements in both schemes. However, compared with a higher-impedance transformer with a medium-impedance transformer and a current-limiting reactor, the device with the current-limiting reactor is added, an equipment room is required to be arranged independently, the occupied area is increased, copper bars are required to be connected for connecting the medium-impedance transformer and the current-limiting reactor, the short-circuit current is very large, the difficulty of external wiring is increased, the external wiring is messy, and the system fault point is increased. The cost will also be higher than for high impedance transformers. Therefore, the main transformer 100 of the embodiment of the present utility model adopts a high-impedance transformer, but this is not to be construed as limiting the present utility model, and a medium-impedance transformer+a current-limiting reactor may be adopted.

In some embodiments of the present utility model, each main transformer 100 is equipped with a reactive compensation device. The reactive compensation device is a device for improving the power factor of a power grid in an electric power supply system, and can reduce the loss of a power supply transformer and a transmission line, improve the power supply efficiency and improve the power supply environment. According to the transformer substation provided by the embodiment of the utility model, the outgoing line is added at the 10kV side, so that the outgoing line cable is added, and the capacitance current is increased by the outgoing line cable, so that reactive compensation is more needed.

In some embodiments of the utility model, the reactive compensation means employs capacitive reactance compensation means. In the capacitive reactance compensation device, the capacitor is mainly used for improving the power factor of a power frequency power system, improving the power supply quality of a power grid and improving the reliability of power utilization; the reactor is a power capacitor matching system and is used for improving the power factor of a power system, effectively inhibiting higher harmonic waves of a power grid, relieving overload of the capacitor caused by the harmonic waves, preventing the harmonic waves from being overlarge, and playing a good role in safe operation of the capacitor, improving network voltage waveforms, improving power supply quality and improving safe and economical operation of the power grid.

It should be noted that other reactive power compensation devices such as an enhanced static reactive power generator may be adopted according to actual situations, and the present utility model is not limited thereto.

In some embodiments of the present utility model, referring to fig. 3, both 220kV bus 200 and 110kV bus 300 are connected in a double bus double segment. When any section of bus has short circuit fault, the sectional reactor will limit short circuit current. When the bus is overhauled, the other bus can still keep parallel operation through switching operation, when one or more generators are out of operation, the short-circuit current of a bus system is reduced, and when the current limiting of a reactor is not needed, the bus and the standby bus can be parallel operated by using a bus-bar breaker, so that the power loss and the voltage loss in the unnecessary sectional reactor are eliminated, the voltages of the two sections of buses are balanced, and the power failure range of the buses is reduced. The reliability and the flexibility of the double-bus double-section wiring mode are higher.

It should be noted that, the 220kV bus 200 and the 110kV bus 300 may also be connected in other manners according to actual needs, and the present utility model is not limited thereto.

In some embodiments of the utility model, referring to fig. 3, 220kV bus 200 with eight-turn line and 110kV bus 300 with fourteen-turn line, each main transformer 100 has a capacity of 240 megavolt-amperes on the 220kV side and 120 megavolt-amperes on the 110kV side, and the capacitive reactance compensation device employs seven 8 megavoltage capacitor banks and two 10 megavoltage reactor banks.

The final period of 220kV outgoing line is considered according to eight times, each time of 220kV line is considered according to a mixed line by reactive power calculation, wherein the cable part is 3.85km, and the overhead line is 10.7km;

the 110kV outgoing line is considered according to fourteen rounds in the final period, and each round of 110kV line is considered according to a cable line of 2.6km in reactive power calculation;

the final period of 10kV outgoing line is considered according to eighty times, and the power supply distance of each outgoing line is calculated according to 3 km;

the load rate is considered according to three conditions of high, medium and low, and the specific data are 80%, 60% and 20% respectively;

the 220kV line charging power is calculated according to one half of the line; 110kV line charging power is calculated according to one half of the full length of the line at high and medium load rates, and is calculated according to the full length of the line at low load rates.

Table 3 is a reactive balance table of a substation according to an embodiment of the present utility model.

Table 3 reactive balance table

Therefore, the reactive compensation of the embodiment of the present utility model is configured to: each main transformer 100 is equipped with seven 8 megavoltage (Mvar) capacitor banks and two 10 megavoltage reactor banks.

Table 4 shows the final scale of the substation according to the example of the present utility model.

Table 4 final scale of substation

In some embodiments of the present utility model, the capacity of the 220kV main transformer 100 of the conventional transformer substation is 240:240:80mva, and since the present utility model is to improve the low voltage direct-matching capability of the main transformer 100, it is necessary to calculate the suitable low voltage side capacity, and it is also possible to calculate whether the conventional main transformer 100 is suitable.

Twenty-four outgoing lines of 10kV are arranged on the low-voltage side of each main transformer 100, and eighty-four outgoing lines are arranged on the whole-station four main transformers 100. According to the actual data of the economical and developed cities of the south network and the national network, the load carried by the 10kV outgoing line is 8000kVA at the highest, and the load capacity carried by the 10kV line is limited by considering that the cable section of the 10kV power distribution network adopts a cable of 3X300mm < 2 >.

The 10kV line load rate is about 40%, the load rate is the most reasonable, the current 10kV line load rate in China is at the same level, and the load of each outgoing line is about 3200kVA according to 8000kVA each time. Twenty times of calculation are performed according to each main transformer 100, and the total load of the low-voltage side of the main transformer 100 is about 64MVA. The load rate of the main transformer is calculated to be 54% according to the average level of the domestic large and medium cities, and the low-voltage side capacity of the main transformer 100 is calculated to be 118.5MVA, so that the low-voltage side capacity of the main transformer is 120MVA. I.e. the capacity of the main transformer 100 is chosen to be 240:240:120mva.

Next, 10kV power supply capacity verification was performed.

The main transformer 100 is a 220/110/10kV low-voltage side double-branch incoming line transformer, the low-voltage side capacity of the transformer is configured according to 120MVA, and in view of the limitation of the maximum working current 4000A of the current 10kV high-voltage switch cabinet, if the main transformer 100 has the low-voltage side 120MVA capacity, the low-voltage side current is about 6600A, and the maximum working current of the switch cabinet is far exceeded. So the main transformer 100 low-side outlet branch has two main schemes, first: the low voltage side of the main transformer 100 is provided with split windings, i.e. the low voltage side of the main transformer 100 is split inside the transformer, each split winding capacity 60MVA. Second,: the low-voltage side single coil of the main transformer 100 is divided into two branches through copper bar lap joints after the low-voltage outgoing line of the main transformer 100. Because the second scheme is branched outside the main transformer 100, not only the charged distance between the copper bars is considered, but also a certain space is provided, which is not as simple as the first scheme. In addition, split windings are arranged in the main transformer 100, double-branch loop current is easy to control, load distribution is average, scheme II load distribution is uneven, and loop current is not easy to control. We consider therefore a main transformer 10010kV low voltage side provided with split windings, outgoing lines in two branches, each branch being provided with a capacity of 60MVA.

Power supply capability calculation under 10kV side switch limit: 4000A x 10.5kV x 1.732 = 72MVA.

When the load rate of the main transformer 100 is 54%, the power supply capacity of the 10kV side is calculated: 120mva×54% =64.8 MVA < 72MVA.

Therefore, the capacity of the main transformer 100 is selected, twenty-back outgoing lines are configured according to the capacity, and the power supply capacity is not affected by 10kV switching current.

Table 5 is a substation power supply capacity meter.

Meter 5 transformer substation power supply capacity measuring and calculating meter

When the 220kV power grid capacity ratio is considered according to 1.9, the average load factor of the 220kV main transformer 100 is about 54%, and when the power supply capacity of the 220kV main transformer 100 is calculated in table 5, the load factor of the main transformer 100 is 54%.

When the load rate of the main transformers 100 is 54%, and four main transformers 100 are aligned, the 10kV side direct power capacity is about 258MVA, the 110kV side power supply capacity is about 258MVA, the number of 110kV power supply main transformers is about eight, and three to four 110kV substations can be carried; when three main transformers 100 are arranged, the 10kV side direct power capacity is about 193MVA, the 110kV side power supply capacity is about 193MVA, and the number of 100 main transformers for 110kV power supply is about six, so that two to three 110kV substations can be carried.

When the load rate of the main transformers 100 of the conventional transformer substation is 54%, the direct capacity of the 10kV side is about 172MVA when the four main transformers 100 are aligned, and the direct capacity of the 10kV side is about 128MVA when three main transformers are arranged, but the power supply capacity of the 110kV side is basically equivalent and has no large change. The conventional 220kV transformer substation has rich power supply capability and fewer 10kV side outgoing lines. Therefore, the 10kV side outlet loop is added, and the 10kV side direct capacity can be obviously improved by about 50%.

In some embodiments of the utility model, according to the equipment manufacturing level of the domestic 10kV switch cabinet, the short-circuit current of the general 10kV high-current switch cabinet is 31.5kA, and meanwhile, according to the related specifications of the low-voltage distribution network, the 10kV side short-circuit current is limited to be not more than 31.5kA by both the south network and the national network, so that the 10kV side short-circuit current of the transformer substation in the embodiment of the utility model is 31.5kA.

In summary, the final model of the main transformer 100 according to the embodiment of the present utility model is:

name: three-phase air-cooled three-winding on-load voltage-regulating 11-type main transformer: SFSZ11-240000/220;

connection group: YN, YN0, d11; capacity: 240:240:120MVA;

voltage ratio: 220+ -8x1.25%/115/10.5 kV;

impedance voltage: uk 1-2=14%, uk 1-3=64%, uk 2-3=50%.

According to the construction scale and the novel wiring mode of the transformer substation, the principle of saving land is adhered to, the arrangement is compact and reasonable, and on the premise of meeting the requirements of safety and reliability, advanced technology, economy and rationality and convenience in operation and maintenance, only one distribution device building is arranged in the center of a station area, and all electrical equipment is arranged in the distribution device building. The distribution device building is arranged as follows:

the axial length of the power distribution device is 98.00m multiplied by 41.0m, the occupied area of the power distribution building is 4018 square meters, the building area is about 11000 square meters, and the total plane area is about 8000 square meters, which is equivalent to that of a traditional 220kV transformer substation.

The distribution device building layers are arranged as follows:

the underground layer (-2.500 m layer) is a cable interlayer;

the ground one layer (1.500 m layer) is a 10kV distribution room, a 220kV GIS room, a 110kV GIS room and a shunt reactor room, and the main transformer is arranged on the 0.00m layer;

the ground two layers (7.500 m layers) are capacitor chambers, grounding transformer chambers and the like;

the three layers (12.500 m layers) on the ground are a station transformer room, a 380V distribution room, a relay and communication room, a storage battery room, a tool room, a spare part room and the like.

According to the embodiment of the utility model, the 220kVGIS, 110kV GIS, main transformer 100 and other large-scale equipment, namely the equipment with large unit weight, are arranged on one layer, so that the structural system of the power distribution device building is a steel structural system, and the national development requirement is met.

Conventional substations typically arrange the main transformer 100 in one layer, 110kV GIS in 2 layers and 220kV in 3 layers. The distribution device building is a high-rise building, the building height exceeds 24 meters, and the fire-fighting facilities and the fire-fighting climbing sites are different from the multi-storey building. In addition, such arrangements typically employ reinforced concrete structures. The large-scale equipment is arranged on one layer, so that the problem of hoisting the large-scale equipment is solved; secondly, the condition that the whole building is light in weight is solved, the calculation of a structural system is facilitated, the section sizes of columns and beams can be saved, and steel can be saved when a steel structural system is adopted.

The embodiments of the present utility model have been described in detail with reference to the accompanying drawings, but the present utility model is not limited to the above embodiments, and various changes can be made within the knowledge of one of ordinary skill in the art without departing from the spirit of the present utility model.

Claims

1. A substation, comprising:

four main transformers (100), each main transformer (100) is provided with a 220kV wire outlet end, a 110kV wire outlet end, a first 10kV wire outlet end and a second 10kV wire outlet end;

a 220kV bus (200) connected with the 220kV outlet end of each main transformer (100);

a 110kV bus (300) connected with the 110kV outlet end of each main transformer (100);

10kV generating line (400) adopts single generating line segmentation eight sections generating line annular wiring modes, 10kV generating line (400) divide into eight sections 10kV sub-generating lines, eight sections 10kV sub-generating line one-to-one with four first 10kV goes out line end and four second 10kV goes out line end and is connected, every section 10kV sub-generating line area ten back are qualified for the next round of competitions.

2. The substation according to claim 1, characterized in that each main transformer (100) employs a split winding transformer with a first high voltage winding connected to the 220kV bus (200), a second high voltage winding connected to the 110kV bus (300), and a double split low voltage winding each connected to one of the 10kV sub-buses.

3. A substation according to claim 2, characterized in that the low-voltage winding of each split low-voltage winding is provided with a low-voltage bushing.

4. The substation according to claim 1 or 2, characterized in that each main transformer (100) employs a high impedance transformer.

5. A substation according to claim 1, characterized in that each main transformer (100) is equipped with reactive compensation means.

6. The substation of claim 5, wherein the reactive compensation device employs a capacitive reactance compensation device.

7. The substation of claim 6, wherein the 220kV bus (200) and the 110kV bus (300) are both connected in a double bus double segment.

8. The transformer substation of claim 7, wherein the 220kV busbar (200) has eight return wires, the 110kV busbar (300) has fourteen return wires, each of the main transformer (100) has a capacity of 240 megavolt-amperes on the 220kV side and the 110kV side, and a capacity of 120 megavolt-amperes on the 10kV side, and the capacitive reactance compensation device employs seven 8 megavoltage capacitor banks and two 10 megavoltage reactor banks.