CN201877704U

CN201877704U - 500kV main transformer 66kVside loop

Info

Publication number: CN201877704U
Application number: CN2010206552135U
Authority: CN
Inventors: 徐荥; 王伟; 于广耀; 耿建风; 顾尔重; 王健; 秦志英; 杨光
Original assignee: Hennan Electric Power Survey and Design Institute
Current assignee: Hennan Electric Power Survey and Design Institute
Priority date: 2010-12-13
Filing date: 2010-12-13
Publication date: 2011-06-22
Anticipated expiration: 2020-12-13

Abstract

The utility model relates to a 500kV main transformer 66kv side loop. A delta bus at the side is connected with a general loop, the general loop is connected with branch loops through 66kV buses, and the general loop consists of a general loop insulation switch and a general loop current mutual inductor which is connected with the general loop insulation switch. The utility model adopting the technical scheme has the following two advantages: 1. the general loop current mutual inductor is reserved so that relay protection configuration is complete and clear; and 2. the general loop insulation switch is reserved, so a certain running flexibility can be provided. When a device is checked and repaired, the insulation switches of the general loop and the branch loops are switched on simultaneously, the device is maintained and overhauled when the insulation switches at the two poles are switched on, so that a main transformer is kept running.

Description

500kV main transformer 66kV side loop

Technical field

The utility model relates to a kind of 500kV main transformer 66kV side loop.

Background technology

500kV main transformer 66kV side is Ais design, i.e. open type power distribution equipment, and its total loop is formed by isolating switch, main breaker summation current transformer.Up to now, most 500kV transforming plant main transformer low-pressure side adopts the Ais power distribution equipment, be generally supported tube type bus, cooperate conventional equipments such as porcelain knob/potting breaker, isolating switch, current transformer, voltage transformer, lightning arrester, constitute medium-sized power distribution equipment outside the room.This design major advantage is that equipment manufacturing cost is low, and weak point is that number of devices is many, integral arrangement complexity, in disorder, and floor space is big, and the operating maintenance workload is big.

GIS is main elements such as bus, circuit breaker, isolating switch, current transformer, voltage transformer, lightning arresters, combined closing is (only exposed externally outlet sleeve pipe or cable termination) in the metal shell of ground connection, fills the switchgear assembly of forming as dielectric with the SF6 gas of certain pressure.The outstanding advantage of GIS is the reliability height, it is clear to arrange, save take up an area of, maintenance workload is little, environmental suitability is strong etc., but price is more expensive comparatively speaking.At present; GIS uses very extensive in power grid construction, but does not use the GIS design in 500kV transformer station low-pressure side, and its reason is the needs that main breaker can not adapt to GIS; so at present when using; usually, so not only make the workman overhaul inconvenience, but also caused the differential range of main transformer too little the whole all deletions of total loop; in a single day the 66kV bus breaks down; excision is postponed fault time, and differential protection is failure to actuate, and can only start backup protection.

Summary of the invention

The purpose of this utility model is: do not establish under the situation of main breaker in 500kV main transformer 66kV side, guarantee that the main transformer differential protection range does not have the dead band, can zero second with regard to start protection, the excision fault proposes a kind of novel 500kV main transformer 66kV side loop.

For achieving the above object, the utility model is by the following technical solutions:

This side △ bus connects total loop, and total loop connects each duplexure by the 66kV bus, and described total loop is made up of total loop isolating switch and coupled total loop current transformer.

Described duplexure comprises electric capacity duplexure and reactance duplexure.

Described duplexure also comprises station power transformation duplexure.

Adopt the utility model of technique scheme, have following 2 advantages: 1) keep the total loop current transformer, make that the relaying protection configuration is complete, clear; 2) keep the total loop isolating switch, certain operational flexibility is provided.When repair apparatus, the isolating switch of total loop and duplexure can be opened simultaneously, under the situation that the two poles of the earth isolating switch is opened, carry out plant maintenance and maintenance, and keep the continuation operation of main transformer.

Description of drawings

Fig. 1 is an overall structure schematic diagram of the present utility model.

Embodiment

As shown in Figure 1, in the utility model, 500kV main transformer 66kV side △ bus 1 connects total loop 2, and total loop 2 connects each duplexure 3 by 66kV bus 9, and above-mentioned total loop 2 is made up of total loop isolating switch 4 and coupled total loop current transformer 5.Promptly in the utility model, total loop 2 is set, but main breaker is not set.Need to prove that above-mentioned △ bus is meant that this external " △ " by conductor formation low pressure winding of three single-phase main transformers connects, and therefore A, B, three buses of C is set, and is called the △ bus.

Above-mentioned duplexure 3 comprises electric capacity duplexure 6 and reactance duplexure 7, can also comprise station power transformation duplexure 8.

The operation principle of the utility model differential protection is: the main transformer differential protection connects from high, medium and low voltage three side current transformers, moves in each duplexure circuit breaker of main transformer height, medium voltage side circuit breaker and low-pressure side.

Protection actuating range: 1) main transformer inside and 1 short circuit of low pressure △ bus, differential protection action, excision main transformer; 2) 66kV bus 9 short circuits, the backup protection action, tripping height, medium voltage side circuit breaker, main transformer is out of service; 3) short circuit behind duplexure 3 circuit breakers, branch circuit breaker excision duplexure; 4) branch circuit breaker tripping, then high, medium voltage side circuit breaker action, excision main transformer.

The utlity model has following 2 advantages: 1) keep total loop CT, so that the relay protection configuration is complete, clear; 2) keep the total loop isolating switch, certain operational flexibility is provided.

Claims

1. 500kV main transformer 66kV side loop, this side △ bus (1) connects total loop (2), total loop (2) connects each duplexure by 66kv bus (9), it is characterized in that: described total loop (2) is made up of total loop isolating switch (4) and coupled total loop current transformer (5).

2. 500kV main transformer 66kV side loop according to claim 1 is characterized in that: described duplexure (3) comprises electric capacity duplexure (6) and reactance duplexure (7).

3. 500kV main transformer 66kV side loop according to claim 2 is characterized in that: described duplexure (3) also comprises station power transformation duplexure (8).