A two-stage voltage reduction power taking method for a high-voltage bus of a substation and a station power connection structure

Abstract

A kind of two-stage step-down power taking method of substation high-voltage bus and station power connection structure, power is taken from 330kV bus, connected with 330kV bus through HGIS circuit breaker, first stage is changed to 10kV through step-down transformer with transformation ratio of 330 / 10kV, 330kV side overvoltage protection is realized by adding arrester on 330kV side of 330 / 10kV step-down transformer, 10kV side overvoltage protection is realized by adding arrester on 10kV side of 330 / 10kV step-down transformer, then second stage is changed to 0.38kV through step-down transformer with transformation ratio of 10 / 0.38kV, voltage measurement is realized by adding voltage transformer on 10kV side of 10 / 0.38kV step-down transformer.The present application saves the initial investment of project, construction and installation are convenient, has the characteristics of installation, maintenance, operation more convenient, safe, reliable, etc., can be effectively applied in practical engineering.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of power transmission and transformation, and relates to a two-stage voltage reduction power taking method for a high-voltage bus of a substation and a station power connection structure. BACKGROUND

[0002] With the rapid development of power grid construction, the coverage of power grid construction is wider and wider. In order to strengthen the network structure, more and more new substations are built in remote areas which are rarely covered before. However, in the early stage of engineering construction, there are often difficulties in taking power from the external power supply within 100 kilometers of the new station site, because there are few substations in the region before and the distribution is sparse. If long-distance transmission is used, the total demand power of the station load is small, resulting in high transmission cost and large loss, and the line maintenance amount is large in the later period, which is very uneconomical. If new energy photovoltaic is used, it is equivalent to building a micro photovoltaic station, the power meets the requirements of the station load, the overall construction cost is high, and it is greatly affected by the region and season, and the operation and maintenance are difficult in the later period. If the energy is extracted by the outgoing high-voltage reactor, the power provided cannot meet the overall power demand of the substation due to the power limitation of the high-voltage reactor. SUMMARY

[0003] The application aims to solve the problem of inconvenient power taking from the external power supply of the new substation in the remote area in the prior art, and provides a two-stage voltage reduction power taking method for a high-voltage bus of a substation and a station power connection structure. The power demand of the internal load is met by two-stage voltage reduction of the high-voltage bus, which can effectively control the investment in equipment in the early stage, and the operation and maintenance workload is small in the later period.

[0004] In order to achieve the above-mentioned purpose, the application has the following technical solutions:

[0005] A two-stage voltage reduction power taking method for a high-voltage bus of a substation, in which the low-voltage load power supply of the substation is taken from a 330kV bus, and is changed to 0.38kV through two-stage voltage reduction to supply power to the low-voltage load of the substation. The first stage is changed to 10kV through voltage reduction by a variable ratio of 330 / 10kV, and the second stage is changed to 0.38kV through voltage reduction by a variable ratio of 10 / 0.38kV.

[0006] As a preferred scheme of the power taking method, the first stage voltage reduction is provided with overvoltage protection between the 330kV side and the 10kV side, and the second stage voltage reduction is provided with voltage measurement on the 10kV side.

[0007] The application discloses a power connection structure of a two-stage voltage reduction power taking substation of a high-voltage bus, which comprises a 330kV wire for leading a 330kV bus to a 330kV HGIS circuit breaker, a 330kV HGIS circuit breaker transformer side bushing is connected to a 330kV side bushing of a 330 / 10kV voltage reduction transformer through the 330kV wire, a 10kV side bushing of the 330 / 10kV voltage reduction transformer is connected to a 10kV cable head, a 10kV side of a 10 / 0.38kV voltage reduction transformer is connected to the 10kV cable head through a 10kV cable, and a 0.38kV side bushing of the 10 / 0.38kV voltage reduction transformer is connected to a through-wall bushing, a 380V bus bridge and a low-voltage distribution screen in sequence to supply power to a load of the substation.

[0008] Preferably, the 330kV wire is connected to the 330kV HGIS circuit breaker through a 330kV tube bus.

[0009] Preferably, the 330kV HGIS circuit breaker transformer side bushing is connected to the 330kV wire through a 330kV tube bus, and a 330kV arrester is connected to the 330kV tube bus.

[0010] Preferably, the 330 / 10kV voltage reduction transformer 10kV side bushing is connected to the 10kV cable head through a 10kV tube bus, and a 10kV arrester is connected to the 10kV tube bus.

[0011] Preferably, the 10 / 0.38kV voltage reduction transformer 10kV side bushing and the other 10kV cable head are connected through a 10kV copper bar, and a 10kV voltage transformer is connected to the 10kV copper bar.

[0012] Preferably, the 10 / 0.38kV voltage reduction transformer 0.38kV side bushing and the through-wall bushing are connected through a 0.38kV copper bar.

[0013] Compared with the prior art, the application has the beneficial effects as follows: for the power taking demand of a new substation power supply outside a remote area, the application adopts a high-voltage bus power taking mode and realizes the power taking through two-stage voltage reduction. Compared with other schemes such as long-distance transmission and a newly-built micro photovoltaic station, the application can effectively control the early-stage equipment investment, the later-stage substation in-station operation and maintenance workload is also small, has a significant engineering practical application value, and reduces the constraining factors of power grid construction. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 The electrical main connection diagram of the application;

[0015] Figure 2Transformer area plan of the present application;

[0016] Figure 3 First stage transformer side lead sectional view of the present application;

[0017] Figure 4 Second stage transformer side lead sectional view of the present application;

[0018] In the drawing: 1-330kV bus; 2-330kV conductor; 3-330kV tube bus; 4-330kV HGIS circuit breaker; 5-330kV arrester; 6-330 / 10kV step-down transformer; 7-10kV tube bus; 8-10kV arrester; 9-10kV cable head; 10-10kV cable; 11-10kV copper bar; 12-10kV voltage transformer; 13-10 / 0.38kV step-down transformer; 14-0.38kV copper bar; 15-wall bushing; 16-380V bus bridge; 17-low voltage distribution screen. DETAILED DESCRIPTION

[0019] The meaning of the letter marks in the drawing is as follows: BSG-outlet bushing; VD-three-phase live display device; DS-disconnector; ES-grounding switch; CT-current transformer; CB-circuit breaker; SA-arrester; LRCT-bushing current transformer; 330TR-330kV station high-voltage on-load voltage regulating transformer; TC-cable terminal; PT-voltage transformer; 10TR-10kV station low-voltage working transformer; FU-fuse; LCT-zero sequence current transformer; ATS-double power automatic switching switch.

[0020] For the power supply demand of new substation outside power supply in remote areas, the present application introduces the idea of high-voltage bus power supply, which is realized by two-stage step-down, effectively controls the early-stage investment of the project, and the later-stage operation and maintenance workload of the substation is also small.

[0021] Referring to Figure 1 , the two-stage step-down power supply of the substation high-voltage bus of the present application adopts 330kV bus power supply, is connected with the 330kV bus through the HGIS circuit breaker, is changed to 10kV through the step-down transformer with a transformation ratio of 330 / 10kV, an arrester is added on the 330kV side of the 330 / 10kV step-down transformer to realize 330kV side overvoltage protection, an arrester is added on the 10kV side of the 330 / 10kV step-down transformer to realize 10kV side overvoltage protection, then the second stage is changed to 0.38kV through the step-down transformer with a transformation ratio of 10 / 0.38kV, and a voltage transformer is added on the 10kV side of the 10 / 0.38kV step-down transformer to realize voltage measurement.

[0022] Referring to Figures 2-4The station power supply structure of the application comprises a 330kV wire 2 for leading the 330kV bus 1 to the 330kV HGIS circuit breaker 4, the 330kV wire 2 is connected to the 330kV HGIS circuit breaker 4 through a 330kV tube bus 3. The 330kV HGIS circuit breaker 4 transformer side bushing is led to the 330kV side bushing of the 330 / 10kV step-down transformer 6 through the 330kV wire 2, the 330kV HGIS circuit breaker 4 transformer side bushing is connected to the 330kV wire 2 through the 330kV tube bus 3, and a 330kV arrester 5 is connected to the 330kV tube bus 3. The 10kV side bushing of the 330 / 10kV step-down transformer 6 is led to the 10kV cable head 9 through a 10kV tube bus 7, and a 10kV arrester 8 is connected to the 10kV tube bus 7. A 10kV cable 10 is led to the 10kV side of the 10 / 0.38kV step-down transformer 13, and another 10kV cable head 9 is led to the 10kV side bushing of the 10 / 0.38kV step-down transformer 13, the 10kV side bushing of the 10 / 0.38kV step-down transformer 13 is connected to the 10kV cable head 9 through a 10kV copper bar 11, and a 10kV voltage transformer 12 is connected to the 10kV copper bar 11. The 0.38kV side bushing of the 10 / 0.38kV step-down transformer 13 is sequentially connected to a through-wall bushing 15, a 380V bus bridge 16 and a low-voltage distribution panel 17 to supply power to the voltage station load. The 0.38kV side bushing of the 10 / 0.38kV step-down transformer 13 is connected to the through-wall bushing 15 through a 0.38kV copper bar 14.

[0023] In order to solve the problem of the power supply outside the newly-built substation, the load demand in the substation is realized by two-stage step-down from the high-voltage bus, which provides a new idea and practical application technical route for the construction of subsequent substation projects.

[0024] The low-voltage load power supply of the substation of the application is taken from the 330kV bus, and is changed to 0.38kV through two-stage step-down to supply power to the low-voltage load of the substation. In terms of spatial arrangement, the power supply of the substation is taken from the end space of the 330kV bus, and is realized through the HGIS circuit breaker, two-stage step-down transformer and other devices, which saves the early-stage investment of the project, is convenient for construction and installation, and has the characteristics of convenience, safety, reliability and the like in installation, maintenance and operation, and can be effectively applied in practical engineering.

[0025] The above is a further detailed description of the application in combination with the preferred embodiments, and the specific embodiments of the application should not be limited to this. For ordinary skilled persons in the art, some simple deductions or substitutions can be made without departing from the concept of the application, and all of them should be regarded as falling within the protection scope of the application.

Claims

1. A substation high-voltage bus two-stage step-down power station power connection structure, characterized in that: The application relates to a two-stage voltage reduction power taking station wiring structure of a substation high-voltage bus, which is used for meeting the demand of station internal load under the condition that external power supply is difficult to obtain in a newly-built substation in a remote area. The two-stage voltage reduction power taking station wiring structure of the substation high-voltage bus comprises a 330kV wire (2) used for leading a 330kV bus (1) to a 330kV HGIS circuit breaker (4), a 330kV HGIS circuit breaker (4) transformer side bushing leading to a 330 / 10kV voltage reduction transformer (6) 330kV side bushing through the 330kV wire (2), a 10kV side bushing of the 330 / 10kV voltage reduction transformer (6) leading to a 10kV cable head (9), leading to a 10 / 0.38kV voltage reduction transformer (13) 10kV side through a 10kV cable (10), and leading to a 10 / 0.38kV voltage reduction transformer (13) 10kV side bushing through another 10kV cable head (9), and a 0.38kV side bushing of the 10 / 0.38kV voltage reduction transformer (13) sequentially supplying power to the substation load through a wall bushing (15), a 380V bus bridge (16) and a low-voltage distribution screen (17); The substation low-voltage load power supply is taken from the 330kV bus, and is changed into 0.38kV through two-stage voltage reduction to supply power to the substation low-voltage load, wherein the first stage is changed into 10kV through a 330 / 10kV voltage reduction transformer, and the second stage is changed into 0.38kV through a 10 / 0.38kV voltage reduction transformer; The first stage voltage reduction is provided with 330kV side and 10kV side overvoltage protection, and the second stage voltage reduction is provided with 10kV side voltage measurement; The 330kV HGIS circuit breaker (4) transformer side bushing is connected with the 330kV wire (2) through a 330kV tube bus (3), and a 330kV arrester (5) is connected to the 330kV tube bus (3); The 10kV side bushing of the 330 / 10kV voltage reduction transformer (6) is led to the 10kV cable head (9) through a 10kV tube bus (7), and a 10kV arrester (8) is connected to the 10kV tube bus (7); The 10kV side bushing of the 10 / 0.38kV voltage reduction transformer (13) and the other 10kV cable head (9) are connected through a 10kV copper bar (11), and a 10kV voltage transformer (12) is connected to the 10kV copper bar (11).

2. The substation high voltage bus two-stage step-down power consumer connection structure according to claim 1, characterized in that: The 330kV wire (2) is connected with the 330kV HGIS circuit breaker (4) through the 330kV tube bus (3).

3. The two-stage voltage reduction power taking station wiring structure of the substation high-voltage bus according to claim 1, wherein: The 0.38kV side bushing of the 10 / 0.38kV voltage reduction transformer (13) and the wall bushing (15) are connected through a 0.38kV copper bar (14).

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