CN102361239A

CN102361239A - Mechanism for non-interrupting power of medium-voltage side of main transformer during repair

Info

Publication number: CN102361239A
Application number: CN2011101633718A
Authority: CN
Inventors: 粟和林; 李旻; 李世平
Original assignee: Electric Power Research Institute of State Grid Sichuan Electric Power Co Ltd
Current assignee: State Grid Corp of China SGCC; Electric Power Research Institute of State Grid Sichuan Electric Power Co Ltd
Priority date: 2011-06-17
Filing date: 2011-06-17
Publication date: 2012-02-22

Abstract

The invention discloses a mechanism for non-interrupting the power of a medium-voltage side of a main transformer during repair. The mechanism comprises a transformer station, wherein the transformer station consists of I# and II# transformers which operate in parallel; 10-kV low-voltage sides of the I# and II# transformers are respectively connected with a reactor DK1 and a reactor DK2 in series and then connected to a 10-kV busbar through a switch and front and rear knives; the I# and II# transformers are 220-kV/110-kV/10-kV transformers or 110-kV/35-kV/10-kV transformers; a first isolation knife is added between the 10-kV low-voltage side of the I# transformer and the reactor DK1; and a second isolation knife is added between the 10-kV low-voltage side of the II# transformer and the reactor DK2. During the test and repair of the reactors, the main transformer can be no longer powered down, so that a10-kV medium-voltage side of the same main transformer can continuously supply power to a user.

Description

The mechanism that in a kind of maintenance the main transformer medium voltage side is not cut off the power supply

Technical field

The present invention relates to transformer substation system, particularly main transformer adopts the transforming plant primary equipment of 220kV/110kV/10kV and 110kV/35kV/10kV.

Background technology

In electric power system; Just like three coil transformers such as 220kV/110kV/10kV and 110kV/35kV/10kV; Low-pressure side 10kV is in series in order to the reactor DK that absorbs electrical network capacitive reactive power and restriction high order harmonic component, like I among Fig. 1 often with limiting short-circuit current with link with capacitor in the line ^#, II ^#Main transformer △ side is to DK1, DK2.

Fig. 1 is the main body mould graphoid of five li heaps transformer station of Sichuan Deyang Electric Power Bureau of Utilities Electric Co.; For the present technique transformation introduce clear; Press the load circuit only to draw two respectively among 220kV high voltage source that links with it and the 110kV, also have multiple branches circuit and other mother and voltage transformer etc. not to be drawn into.

In Fig. 1,220kV voltage through 201 switches and 2011 and 2013 or 2012 and 2013 disconnecting links, sends I by I, II bus to by sending here from Tan's five lines etc. ^#The main transformer high-pressure side; After step-down, the 110kV medium voltage side is supplied with users such as five high lines, five moral lines through 101,151,152 switches set, and low-pressure side 10kV is then through reactor DK1 and switch 901 and disconnecting

link

9011,9013; Give 10kV bus row; Through switch 911,912 switches and front and back disconnecting

link

9111 and 9113 and 9121 and 9123, two groups charge power supply is provided again, so that do reactive power compensation and improve rate of qualified voltage to one group in capacitor and capacitor; Corresponding 9611,9613 disconnecting links of 961 switches institute are then supplied with I ^#Stand and use with transformer.

II among Fig. 1 ^#Main transformer high-pressure side 202 switches link to each other with I, II bus with 2023 disconnecting links with 2023 or 2022 with 2021, obtain the 220kV power supply, with I ^#Main transformer forms paired running, and the 110kV medium voltage side is supplied with relevant loads such as five high lines through 101,151,152 switches set, supplies with 10kV bus row through 902 switches set again, supplies with capacitor charging and II through 921,922,962 switches set again ^#Stand and use, because of capacity, model, branched line and connected mode and the I of each corresponding device with becoming ^#Main transformer is similar, has only the sequence number difference, so no longer carefully state in this.

Because capacitor charging/discharging is nonlinear-load, so pulsation harmonic amount is bigger, capacitor self is overheated, it is more to expand, be out of shape; As being connected between main transformer and the electric capacity bus row, play inductive load---the reactor of leveling, also can receive uniform impingement and influence, so need regularly and aperiodically to carry out single-phase equally or three-phase power failure test and maintenance.

Visible from Fig. 1, because main transformer 10kV side is directly to link to each other with reactor,, main transformer is had a power failure so reactor need be done when overhauling, just can carry out.Main transformer has a power failure, though guaranteed the safety of 10kV side, by same main transformer with the power supply of 110kV medium voltage side also be interrupted, the problem of drawing like this is:

1, will reduce power supply in electric power system, more will cause power failure, and all can suffer economic loss the user.

Even if 2 can change another main transformer power supply by no overhaul of the equipments, but this main transformer load is increased the weight of, and operate and increase, also must influence coefficient of safety.

Summary of the invention

The purpose of this invention is to provide the mechanism that makes main transformer medium voltage side uninterrupted power supply, even under the situation of reactor trouble hunting, the 110kV medium voltage side also can continue to supply power to the user.

The objective of the invention is to realize like this: the mechanism that in a kind of maintenance the main transformer medium voltage side is not cut off the power supply comprises, by the I of paired running ^#, II ^#The transformer station that transformer is formed: I ^#, II ^#Transformer is respectively through corresponding switchgear and I ^#, II ^#Bus links to each other and obtains 220kV voltage, above-mentioned I ^#, II ^#Behind the 10kV low-pressure side difference tandem reactor DK1 and reactor DK2 of transformer, be connected to 10kV bus row through switch and forward and backward disconnecting link thereof again; Above-mentioned I ^#, II ^#Transformer is 220kV/110kV/10kV transformer or 110kV/35kV/10kV transformer, I ^#Be connected with first isolation switch of setting up, II between the 10kV low-pressure side of transformer and the reactor DK1 ^#Be connected with second isolation switch of setting up between the 10kV low-pressure side of transformer and the reactor DK2.

Above-mentioned first isolation switch and second isolation switch all adopt GW9 type 630A disconnecting link, and this disconnecting link is selected according to the load current size, and other similar structures can be as reference.

Beneficial effect of the present invention is: when need are tested service work to the reactor of main transformer 10kV side connection; After breaking off the respective switch group, draw back newly-increased disconnecting link, can carry out; Main transformer then can no longer have a power failure, thus guarantee by main transformer with the 110kV medium voltage side continue to supply power to the user.

Advantage of the present invention will combine embodiment further to set forth.

Description of drawings

Fig. 1 is original power transformation station owner simulation drawing (other mother draws with branched line entirely).

Fig. 2 is the power transformation station owner simulation drawing (Fig. 1 has increased dotted portion relatively) among the present invention.

Fig. 3 is newly-increased disconnecting link scheme of installation.

Embodiment

Fig. 2 illustrates; The mechanism of main transformer medium voltage side uninterrupted power supply is comprised by two 220kV/110kV/10kV transformers of paired running or by two transformer stations that the 110kV/35kV/10kV transformer is formed of paired running; And behind the 10kV low-pressure side of above-mentioned two transformers difference tandem reactor DK1 and the DK2, be connected to 10kV bus row through switch and forward and backward disconnecting link thereof again; The 220kV/110kV/10kV I ^#Be connected with first isolation switch of setting up 9012 between the 10kV low-pressure side of transformer and the reactor DK1, the 220kV/110kV/10kV II ^#Be connected with second isolation switch of setting up 9022 between the 10kV low-pressure side of transformer and the reactor DK2.

First isolation switch 9012 and second isolation switch 9022 are chosen to be GW9 type 630A disconnecting link according to the load current of about 400A.

Referring to Fig. 1, to the feasibility that installs isolation switch additional and have or not and possibly draw other fault, we have made the correlation analysis demonstration: because will overhaul reactor, switch 901 or 902 must break off earlier; Draw back 9013 or 9023 disconnecting links again, at this moment, newly-increased disconnecting

link

9012 or 9022 and 9013 or 9023 is in the circuit of same nature; Because of the switch outage, zero load electric current is not so can produce arc spark in the operation; Promptly can not bring added influence, so it is fully feasible installing this disconnecting link additional.

Thus, we have implemented the line design of this disconnecting link such as Fig. 2, and newly-increased disconnecting link 9012 is put in I ^#In the frame of broken lines of main transformer and reactor DK1; 9022 are put in II ^#In the frame of broken lines of main transformer and reactor DK2.According to the load condition of 10kV side electric current about 400A, we have selected the big capacity disconnecting link of GW9 type (specified 630A).

Transforming assembling like Fig. 3, is anti-rainwater and industrial pollution corrosion, in addition reactor be placed in indoor, this indoor having living space, but owing to having only one group of disconnecting link, so need not to do the comprehensive assembling of high-voltage board, we are chosen in it on wall and assemble for this reason.

Visible from Fig. 3, draw from main transformer 10kV side after following bus row 1 gets within doors, under the support of porcelain insulator 2 and busbar supporting bracket 3; Send fixed contact 4 to; Operating handle 13 is connected in 5 of moving contacts and the control box 11, under staff's push-and-pull, through the connection transformation of power transmission shaft 6; Realize branch, the combined floodgate of disconnecting link, and the divide-shut brake Pointing sign board 12 of interlock is made the corresponding indication of divide-shut brake with it.The static contact and insulation porcelain vase all links to each other with brandreth plate 8 with moving contact porcelain insulator 7, and the brandreth plate is fixed on the wall 10, like this, accomplishes the processing such as operation assembling and insulation safety of quiet, moving contact.

Newly-increased disconnecting link installs, and after machinery such as moment, pressure, megger, contact resistance, electrical are errorless, can come into operation, and divide two aspects to see effect:

1, ruuning situation: when the staff pushes to original and newly-increased disconnecting link, in the throwing behind the switch 901,902, the 10kV power supply will send reactor, capacitor to, stand with becoming through output busbar 9 by normal condition, visible operational effect with transform before just the same.

2, maintenance situation: when the reactor DK1 that main transformer 10kV side is connected when need tests maintenance, in I ^#The main transformer low-pressure side is broken off 901 switches, draw back former 9013 disconnecting links after, draw back 9012 newly-increased disconnecting links again, can carry out related work, I thus ^#Main transformer then can no longer have a power failure; In like manner, when the reactor DK2 that main transformer 10kV side is connected when need tests maintenance, in II ^#The main transformer low-pressure side is broken off 902 switches, draw back former 9023 disconnecting links after, draw back 9022 newly-increased disconnecting links again and can carry out pass work,, II thus ^#Main transformer also can no longer have a power failure.

From last visible, add 9012 disconnecting links and 9022 disconnecting links after, great changes is before and after transforming---

In the anti-device test maintenance, this 220kV/110kV/10kV I ^#, II ^#Main transformer can no longer have a power failure, and the 110kV medium voltage side just can reach the transformation purpose incessantly to user's power supply thus.

This installs the method and the experience of isolation switch additional between main transformer and reactor; The transformer station that comprises many analog structures of 110kV/35kV/10kV all can be applicable; When making reactor test maintenance, main transformer can continue operation, and medium voltage side keeps supplying power to the user; To reducing the loss, the enhancement apparatus utilance benefits thus.

Claims

1. the mechanism that in the maintenance main transformer medium voltage side is not cut off the power supply comprises, by the I of paired running ^#, II ^#The transformer station that transformer is formed: I ^#, II ^#Transformer is respectively through corresponding switchgear and I ^#, II ^#Bus links to each other and obtains 220kV voltage, above-mentioned I ^#, II ^#Behind the 10kV low-pressure side difference tandem reactor DK1 and reactor DK2 of transformer, be connected to 10kV bus row through switch and forward and backward disconnecting link thereof again; Above-mentioned I ^#, II ^#Transformer is 220kV/110kV/10kV transformer or 110kV/35kV/10kV transformer, it is characterized in that: said I ^#Be connected with first isolation switch of setting up (9012) between the 10kV low-pressure side of transformer and the reactor DK1, II ^#Be connected with second isolation switch of setting up (9022) between the 10kV low-pressure side of transformer and the reactor DK2.

2. the mechanism that in a kind of maintenance according to claim 1 the main transformer medium voltage side is not cut off the power supply, it is characterized in that: said first isolation switch of setting up (9012) and second isolation switch (9022) all adopt GW9 type 630A disconnecting link.