CN202488121U

CN202488121U - Current-limiting device for substation 10kV loop

Info

Publication number: CN202488121U
Application number: CN2012200451479U
Authority: CN
Inventors: 王宏斌; 郭萌; 李海烽; 查申森; 胡继军; 邓广静; 熊静; 邵俊伟; 刘苏琴; 孔丹晖; 项玲; 陈斌
Original assignee: Jiangsu Electric Power Design Institute
Current assignee: China Energy Engineering Group Jiangsu Power Design Institute Co Ltd
Priority date: 2012-02-13
Filing date: 2012-02-13
Publication date: 2012-10-10
Anticipated expiration: 2022-02-13

Abstract

The utility model discloses a current-limiting device for a substation 10kV loop. The current-limiting device comprises a current-limiting reactor, an isolating switch and a current transformer, wherein the current-limiting reactor, the isolating switch and the current transformer are divided into two groups and are respectively connected to each 10kV branch. The two groups of the current-limiting reactors are mounted on independent 10kV branches, so that the current-limiting device does not have special requirements on load distribution of the 10kV branch loop, the voltage drop on the two groups of the current-limiting reactors is lower than that of the current-limiting reactor in a total loop in a normal operating state, and when the current-limiting reactor in one branch loop fails, the other branch loop can continuously operate; and therefore, the main substation shutdown is avoided, and the current-limiting device has the characteristics of no special requirement of branch load distribution, low voltage drop during normal operation and low shutdown probability of the main substation due to failure of the reactor, and has good application prospect.

Description

The current-limiting apparatus that is used for transformer station 10kV loop

Technical field

The utility model relates to the power technology field, is specifically related to a kind of current-limiting apparatus that is used for transformer station 10kV loop.

Background technology

At present, 220kV transforming plant main transformer depressor often adopts the 220/1102/10kV electric pressure, considers power system operation regulation and device fabrication level; Transformer station is in the voltage fluctuation allowed band; Main transformer 10kV side maximum short circuit current should be controlled at below the 20kA, and according to State Grid Corporation of China's universal design, 220kV transformer station separate unit main transformer capacity is generally 180MVA or 240MVA; When main transformer separate unit capacity is 180MVA and when following; Through calculation of short-circuit current, when 10kV side short circuit current exceeds standard, should select for use the high impedance main transformer with restriction 10kV side short circuit current.When main transformer separate unit capacity is 240MVA; Adopt the high impedance main transformer can not 10kV side short circuit current be limited in below the 20kA, adopt conventional impedance main transformer usually, and increase reactor in the 10kV side; 10kV side short circuit current is limited in below the 20kA; The mode that the 10kV side increases reactor has two kinds, has defective separately simultaneously, specifically describes as follows:

One, increase current limiting reactor, concrete wiring is as shown in Figure 1, and the common capacity of 240MVA main transformer 10kV side is 80MVA or 120MVA; Its rated current has all surpassed conventional 10kV switch cubicle rated current, and the 10kV side adopts two branches inlet wire structure, and current limiting reactor is arranged on the main transformer 10kV side total loop; Here be called the total loop current limiting reactor, its wiring is succinct, and the sharing of load of duplexure is not had specific (special) requirements; The engineering initial investment is relatively low, but because the total loop rated current is big, used current limiting reactor reactance Rate often reaches about 15%; Voltage landing is bigger under the normal operating condition, and the 10kV busbar voltage is dragged down.

Two, increase split reactor; Concrete wiring is as shown in Figure 2; Reactance value was much lower than the value that single loop flows through electric current when reverse current was flow through simultaneously in the split reactor double loop; Therefore the voltage landing of split reactor is lower under the normal operating condition, but when short circuit accident took place, split reactor is limiting short-circuit current preferably.But install under the split reactor situation, the equilibrium of should trying one's best of the load of the two duplexures of 10kV, the electric current of each branch should not surpass 70% of total loop, implement very inconvenient.

The utility model content

The utility model technical problem to be solved is to overcome to increase the problem that the voltage landing under normal operating condition of total loop current limiting reactor is big and the balanced two duplexure loads of increase split reactor are not easy to realize; A kind of current-limiting apparatus that is used for transformer station 10kV loop is provided; Can 10kV side short circuit current be limited in below the 20kA; And little, the no branch of voltage landing sharing of load specific (special) requirements can satisfy normal operation the time, can also reduce main transformer because of the stop transport probability of generation of reactor fault.

In order to solve the problems of the technologies described above, the technical scheme that the utility model adopted is:

A kind of current-limiting apparatus that is used for transformer station 10kV loop comprises current limiting reactor, it is characterized in that: said current limiting reactor is two groups, is installed in respectively on the 10kV of transformer station two duplexures.

The aforesaid current-limiting apparatus that is used for transformer station 10kV loop is characterized in that: the isolating switch summation current transformer of connecting with said current limiting reactor all is installed in the said 10kV duplexure.

The beneficial effect of the utility model is: two groups of current limiting reactors are installed in respectively on each duplexure of 10kV; Can 10kV side short circuit current be limited in below the 20kA; Be installed on the separate branch branch road owing to two groups of current limiting reactors again; Thereby the duplexure sharing of load to 10kV does not have specific (special) requirements, and simultaneously the voltage landing on two groups of current limiting reactors is little than total loop under the normal operating condition, can also be when a duplexure current limiting reactor breaks down; Another duplexure still can continue operation; The generation of having avoided main transformer to stop transport has the sharing of load specific (special) requirements of no branch, voltage lands little, main transformer because of the low characteristics of reactance fault stoppage in transit probability when normally moving, and has a good application prospect.

Description of drawings

Fig. 1 is the wiring schematic diagram of traditional increase total loop current limiting reactor.

Fig. 2 is the wiring schematic diagram of traditional increase split reactor.

Fig. 3 is the wiring schematic diagram of the current-limiting apparatus that is used for transformer station 10kV loop of the utility model.

Fig. 4 is the concrete winding diagram of the current-limiting apparatus that is used for transformer station 10kV loop of the utility model.

Fig. 5 is the floor plan of the current-limiting apparatus that is used for transformer station 10kV loop of the utility model.

Embodiment

To combine Figure of description below, the utility model will be described further.Following examples only are used for more clearly explaining the technical scheme of the utility model, and can not limit the protection range of the utility model with this.

As shown in Figure 3, a kind of current-limiting apparatus that is used for transformer station 10kV loop comprises current limiting reactor; Said current limiting reactor is two groups; Be installed in respectively on the 10kV of transformer station two duplexures,, thereby the duplexure sharing of load of 10kV do not had specific (special) requirements owing to two groups of current limiting reactors are installed on the separate branch branch road; Simultaneously the voltage landing on two groups of current limiting reactors adopts the total loop current limiting reactor little under the normal operating condition; It is bigger to have overcome the voltage landing under normal operating condition of increase total loop current limiting reactor, and increases the problem that the balanced two duplexures loads of split reactor are not easy to realize, wherein to adopt rated current be 3000A to the used current limiting reactor of the utility model; Short circuit current 50kA; Reactance Rate is 10% single-phase, dry-type air-core reactor, and the extensive use in the transformer station at home of the current limiting reactor of this pattern belongs to national grid project of transmitting and converting electricity common apparatus.

Yongsheng 220kV transformer station and Su Zhouzhou city 220kV transformer station implement the current-limiting apparatus that is used for transformer station 10kV loop of the utility model in Zhenjiang; And the operation of going into operation; Concrete wiring is as shown in Figure 4; One group of isolating switch summation current transformer of series connection before the current limiting reactor of 10kV duplexure, when one section 10kV bus of main transformer low-pressure side breaks down, the main transformer switch cabinet inner breaker tripping of this section bus; Another section of main transformer low-pressure side 10kV bus still can normally move, and has reduced the probability that main transformer is stopped transport because of the reactance fault.In addition, after opening the main transformer inlet wire isolating switch of this section bus, the 10kV main transformer switch cabinet on this section of interruption maintenance bus not.

As shown in Figure 5; The floor plan of the current-limiting apparatus that is used for transformer station 10kV loop of the utility model comprises many main transformers and branch thereof, and wherein every main transformer is divided into two groups of current limiting reactors; For the better utilization space resources; Adopt vertical closed assembly to arrange, and place reactor indoor two groups of current limiting reactors, current limiting reactor has been played protected the influence that does not receive external environment.Under this arrangement, be provided with semi-insulating bus and 10kV isolating switch between reactor chamber and the main transformer, consider the installation and the maintenance of reactor, between 10kV isolating switch and reactor chamber, also be provided with the reactor transport channel.

In sum; Though the utility model increases the total loop current limiting reactor or split reactor needs many one group of reactors and corresponding investment; But it is low that the reactance Rate of the used current limiting reactor of branch and rated current are compared with total loop current limiting reactor and split reactor, and at present, the used current limiting reactor of two group of branches (reactance Rate 10%) increases about 15% ~ 20% than one group of total loop reactor (15%) equipment price; But has the sharing of load specific (special) requirements of no branch; Little, the main transformer of voltage landing is because of technical advantages such as reactance fault stoppage in transit probability are low during normal operation, total loop current limiting reactor and split reactor relatively, and the duplexure reactor has improved the flexibility and the reliability of 10kV system; Reduce the operation cost of 10kV system, have a good application prospect.

More than show and described basic principle, principal character and the advantage of the utility model.The technical staff of the industry should understand; The utility model is not restricted to the described embodiments; The principle of describing in the foregoing description and the specification that the utility model just is described; Under the prerequisite that does not break away from the utility model spirit and scope, the utility model also has various changes and modifications, and these variations and improvement all fall in the utility model scope that requires protection.The utility model requires protection range to be defined by appending claims and equivalent thereof.

Claims

1. be used for the current-limiting apparatus in transformer station 10kV loop, comprise current limiting reactor, it is characterized in that: said current limiting reactor is two groups, is installed in respectively on the 10kV of transformer station two duplexures.

2. the current-limiting apparatus that is used for transformer station 10kV loop according to claim 1 is characterized in that: the isolating switch summation current transformer of connecting with said current limiting reactor all is installed in the said 10kV duplexure.