CN103840378A - Improved PT1 type power distribution station - Google Patents

Abstract

The invention provides an improved PT1 distribution station. One 10kV incoming line is connected to a transformer through a 10kV load switch. The transformer converts the 10kV incoming line voltage into 0.4kV and then outputs it, and further connects to a 0.4kV bus through a 0.4kV switch. The multiple outgoing lines under the 0.4kV busbar are respectively provided with outgoing line switches, and a group of 0.4kV capacitors are connected to the 0.4kV busbar through capacitor switches; the 10kV load switch is set in the SF6 ring network cabinet, the 0.4kV switch, outgoing line The capacitor switch is a vacuum circuit breaker installed in the GGD cabinet. The invention replaces the primary equipment of the distribution station without changing the original scale and the main wiring mode, which is beneficial to improving the health level and safe operation level of the equipment, reducing the workload of inspection and maintenance, and improving the reliability of power supply.

Description

An Improved PT1 Distribution Substation

technical field

The invention relates to the field of power distribution, in particular to an improved PT1 distribution station. the

Background technique

When supplying power to commercial areas and residential buildings, users generally have relatively high requirements for power supply reliability. In some distribution stations put into operation in the 1980s, a distribution transformer with a capacity of 800kVA was operated, the 10kV side was the incoming line of the load switch, and the 0.4kV wiring was connected with a single busbar.

As shown in Figure 1, a 10kV incoming line is connected to the transformer through the load switch S1. The transformer converts the 10kV incoming line voltage to 0.4kV and outputs it, and further connects to the 0.4kV bus through the 0.4kV switch S2. The 0.4kV bus has a Each of the eight outgoing lines is provided with an outgoing line switch, and a group of 0.4kV capacitors are connected to the bus through capacitor switches.

Figure 2 is the floor plan of the existing distribution station. The high-voltage load switch uses FN3-10 high-voltage switch to control the connection or disconnection between the 10kV incoming line and the transformer; the low-voltage room uses the PGL2 cabinet as the 0.4kV low-voltage incoming line cabinet. , 0.4kV low-voltage outlet cabinet and capacitor cabinet to arrange the corresponding switches.

However, the above-mentioned existing distribution stations have outdated equipment, no spare parts, and poor power supply reliability, making it difficult to meet the growing demand for electricity. However, distribution stations that supply power to commercial areas and residential buildings are often limited by the site, making it difficult to expand the scale and difficult to transform.

Contents of the invention

The purpose of the present invention is to provide an improved PT1 distribution station, which can replace the primary equipment of the distribution station without changing the original scale and main wiring mode, so as to improve the reliability of power supply of the equipment.

In order to achieve the above object, the technical solution of the present invention is to provide an improved PT1 distribution station, which includes:

A 10kV incoming line is connected to the transformer through a 10kV load switch. The transformer converts the 10kV incoming line voltage to 0.4kV and then outputs it, and further connects to the 0.4kV bus through a 0.4kV switch. The multiple outgoing lines under the 0.4kV bus are respectively equipped with Outgoing switch, a group of 0.4kV capacitors are connected to the 0.4kV bus through capacitor switches;

The 10kV load switch is set in the SF6 ring network cabinet, and the 0.4kV switch, outlet switch, and capacitor switch are vacuum circuit breakers set in the GGD cabinet.

Preferably, one end of the 10kV load switch is connected to the 10kV incoming line, and the other end of the 10kV load switch is divided into two circuits after passing through a fuse and a current transformer. to the transformer.

Preferably, one end of the 10kV load switch is connected to the 10kV incoming line, and the other end of the 10kV load switch is divided into three lines after passing through the current transformer, two lines are respectively connected to the grounded capacitor and lightning arrester, and the other end is connected to the outlet end.

Preferably, the neutral point grounding form of the transformer is direct grounding; a group of lightning arresters are installed on the 10kV side of the transformer.

Preferably, a group of SF6 ring network cabinets with 10kV load switches are located in the high-voltage room;

One 0.4kV low-voltage incoming line cabinet with 0.4kV incoming line switch, four 0.4kV low-voltage outgoing line cabinets with two outgoing line switches each, and one 0.4kV low-voltage capacitor cabinet with capacitor switch are located in the low-voltage room; the transformer passes through the low-voltage The copper busbar is connected to the 0.4kV low-voltage incoming cabinet in the low-voltage room.

Preferably, an SF6 alarm device is provided in the SF6 ring network cabinet.

Compared with the prior art, the PT1 distribution station provided by the present invention replaces the primary equipment of the distribution station without changing the original scale and main wiring mode, and installs SF6 load switches and SF6 alarm devices. It is conducive to improving the health level and safe operation level of equipment, reducing the workload of inspection and maintenance, and improving the reliability of power supply.

Description of drawings

Figure 1 is a schematic diagram of the electrical wiring of an existing distribution station;

Figure 2 is a layout plan of the existing distribution station;

Fig. 3 is a schematic diagram of 10kV electrical wiring in the PT1 type distribution station of the present invention;

Fig. 4 is the schematic diagram of 0.4kV electrical wiring in the PT1 type distribution station of the present invention;

Fig. 5 is a plane layout diagram of the distribution station of the present invention.

Detailed ways

As shown in Figures 3 and 4, the present invention provides a PT1 type distribution station (PT1 type, that is, a ring network distribution station with a distribution transformer and a 10kV outgoing line), and a 10kV incoming line is connected to the Transformer, which converts the 10kV incoming line voltage to 0.4kV and then outputs it, and further connects to the 0.4kV busbar through the 0.4kV switch S2. Capacitor switch S4 is connected to this bus.

The 10kV load switch is located in the high-voltage room, equipped with 2 SF6 ring network cabinets for 10kV incoming and outgoing lines, and 1 SF6 ring network cabinet for 10kV distribution transformer.

In the SF6 ring network cabinet shown in Figure 3, a switchgear is arranged in the following way: one end of the load switch is connected to the 10kV incoming line, and the other end of the load switch is connected to the ground through a fuse and a current transformer. , and the other is connected to the outlet terminal and further connected to the transformer through the outlet cable; each switch cabinet is also equipped with SF6 pressure indicator, capacitor voltage indicator, short circuit fault indicator, three-position switch auxiliary contact, gas pressure auxiliary contact points, fuse auxiliary contacts, etc.

The other two switchgears use the following another device arrangement: the load switch is divided into three circuits after passing through the current transformer, which are respectively connected to the outlet terminal and the grounded capacitor and lightning arrester, and can be connected to the transformer through the outlet terminal, or connected to other switch cabinets The devices in are matched and connected to meet different wiring needs.

The short-circuit current level of this period is selected with reference to the previous equipment, that is, the short-circuit current level of 10kV is considered as 20kA. The parameters of the optimal load switch are as follows: rated voltage 12 kV, rated current 630 A, rated breaking capacity 346 MVA, rated breaking current 20 kA, dynamic stable breaking current peak value 50 kA, 4-second thermal stable current 20 kA.

In addition, combined with an equipment transformation, the corresponding incoming and outgoing cables were reconnected, and flame-retardant cables were used. For example, the ZA-YJV-8.7/10-3X70 cable is used for the 10kV side incoming line, and the low-voltage copper busbar is used for the 0.4kV side outgoing line of the distribution transformer. 5*40 flat iron is used for the grounding of the primary equipment in each position, and is connected to the indoor grounding trunk line.

The 10kV/0.4kV transformer is located in the distribution room and is used to convert the 10kV incoming line voltage to 0.4kV output, and the neutral point grounding form of the transformer is direct grounding. A group of 10kV incoming lightning arresters are installed on the 10kV incoming line side of the transformer to protect against lightning.

As shown in Figure 4, all switches on the 0.4kV side are located in the 0.4kV switch room, and each switch uses a vacuum circuit breaker to connect or disconnect the corresponding outgoing line or its power supply part. The power distribution station of the present invention is provided with one 0.4kV incoming line switch, eight outgoing line switches, and one capacitor switch. It is equipped with 1 0.4kV low-voltage incoming line cabinet, 4 0.4kV low-voltage outgoing line cabinets, 1 0.4kV low-voltage capacitor cabinet, and 1 set of SF6 alarm device.

That is, the 0.4kV low-voltage side of the transformer is connected to the 0.4kV bus through the 0.4kV incoming switch S2 and the current transformer, and the corresponding outgoing line switches S3 and current transformers are respectively set on the eight outgoing lines below. A group of capacitors (240kVar) play the role of reactive power compensation, installed in the capacitor cabinet, and connected to the 0.4kV bus through the capacitor switch S4.

As shown in Figure 5, it is the plane layout of the distribution station of the present invention, a group of SF6 ring network cabinets 4 are located in the high-voltage room; the low-voltage room is equipped with 6 GGD cabinets, and the P1 cabinet is a 0.4kV low-voltage incoming line with a 0.4kV incoming line switch Cabinets, P2-P5 cabinets are 0.4kV low-voltage outlet cabinets with 2 outlet switches, and P6 cabinets are 0.4kV low-voltage capacitor cabinets with capacitor switches; in this example, an auxiliary SF6 alarm device is equipped. The transformer is connected to the corresponding equipment in the high-voltage room and the low-voltage room through corresponding incoming and outgoing cables.

According to the pollution level of the station site, the creepage ratio distance of the project equipment in this phase is selected according to Class III, that is, the creepage ratio distance of equipment with 10V and below is considered as 31mm/kV outdoors and 25mm/kV indoors. Fireproof sealing shall be carried out at all cable holes and gaps at the bottom of newly added power distribution device rooms and protective screen cabinets, as well as at cable interlayers, wall-through floors, walls, cabinets, and panels involved in cable renovation and new additions. And the cable sheath within 1m on both sides of the blockage shall be pasted with fireproof tape or coated with fireproof paint.

As shown in Figure 2 and Figure 5, in this example, the equipment in the high-pressure room and the low-voltage room can be remodeled within the existing station site without additional land acquisition.

To sum up, the PT1 type distribution station provided by the present invention can replace the primary equipment of the distribution station without changing the original scale and electrical wiring mode, set SF6 load switch and equip SF6 alarm device, which is beneficial to Improve the health level and safe operation level of equipment, reduce the workload of inspection and maintenance, and improve the reliability of power supply.

Although the content of the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as limiting the present invention. Various modifications and alterations to the present invention will become apparent to those skilled in the art upon reading the above disclosure. Therefore, the protection scope of the present invention should be defined by the appended claims.

Claims (6)

1. An improved PT1 type power distribution station, characterized in that it comprises: A 10kV incoming line is connected to the transformer through a 10kV load switch. The transformer converts the 10kV incoming line voltage to 0.4kV and then outputs it, and further connects to the 0.4kV bus through a 0.4kV switch. The multiple outgoing lines under the 0.4kV bus are respectively equipped with Outgoing switch, a group of 0.4kV capacitors are connected to the 0.4kV bus through capacitor switches; The 10kV load switch is set in the SF6 ring network cabinet, and the 0.4kV switch, outlet switch, and capacitor switch are vacuum circuit breakers set in the GGD cabinet. 2. The PT1 type distribution station as claimed in claim 1, characterized in that, One end of the 10kV load switch is connected to the 10kV incoming line, and the other end of the 10kV load switch is divided into two circuits after passing through a fuse and a current transformer. One is grounded through a capacitor, and the other is connected to the outlet terminal and connected to the transformer through an outlet cable. 3. The PT1 type distribution station according to claim 1, characterized in that, One end of the 10kV load switch is connected to the 10kV incoming line, and the other end of the 10kV load switch is divided into three circuits after passing through the current transformer. 4. The PT1 type distribution station according to claim 1, characterized in that, The neutral point grounding form of the transformer is direct grounding; a group of lightning arresters is installed on the 10kV side of the transformer. 5. The PT1 type distribution station according to claim 1, characterized in that, A group of SF6 ring main unit with 10kV load switch is located in the high voltage room; One 0.4kV low-voltage incoming line cabinet with 0.4kV incoming line switch, four 0.4kV low-voltage outgoing line cabinets with two outgoing line switches each, and one 0.4kV low-voltage capacitor cabinet with capacitor switch are located in the low-voltage room; the transformer passes through the low-voltage The copper busbar is connected to the 0.4kV low-voltage incoming cabinet in the low-voltage room. 6. The PT1 type distribution station as claimed in claim 2 or 3 or 5, characterized in that, An SF6 alarm device is installed in the SF6 ring network cabinet.

Images