CN101462501B

CN101462501B - AT traction electric power supply system of 27.5KV AC electrification railway

Info

Publication number: CN101462501B
Application number: CN2009100581174A
Authority: CN
Inventors: 李群湛; 贺建闽; 解绍锋; 陈民武; 易东; 郭锴
Original assignee: Southwest Jiaotong University
Current assignee: Southwest Jiaotong University
Priority date: 2009-01-13
Filing date: 2009-01-13
Publication date: 2011-03-30
Anticipated expiration: 2029-01-13
Also published as: CN101462501A

Abstract

The invention relates to an AT traction power supply system of a 27.5KV alternating current gasification railway. The system comprises: the output voltage of a traction transformer (S) of a traction substation is 27.5kV; one output end (M) of the traction transformer (S) is connected with a steel rail (R); the other output end (N) is connected with a positive feeder (F) of a railway traction net; an autotransformer (AT) with transformation ratio of 2 to 1 is arranged in the railway traction net every other 10 to 20 km; one end (a) of the autotransformer (AT) is connected with a railway contact line (T); a center (o) is connected with the steel rail (R); and the other end (b) of the autotransformer (AT) is connected with the positive feeder (F) of the railway traction net. The system has the advantages of the AT power supply system and has small equipment investment, small engineering quantity and easy overhauling and maintenance; moreover, the system is easy to reconstruct the prior direct supply and BT mode railway, and is convenient to implement, and favorable for development of a high-speed overloading railway.

Description

A kind of 27.5kV ac electrified railway AT tractive power supply system

Technical field

The present invention relates to a kind of electric railway AT tractive power supply system.

Background technology

Current ac electrified railway tractive power supply system mainly adopts direct feeding system, BT power supply mode and three kinds of power supply modes of AT power supply mode.

Direct feeding system: as shown in Figure 1, by the single-phase voltage of traction transformer S output 27.5KV, directly with the contact wire T formation that links to each other with rail R.Its advantage is simple in structure, and investment is minimum; Thereby shortcoming is to have electric current to flow through on the rail to produce loss in voltage on rail, make the current potential of rail higher, train sails out of that traction transformer is far away more, its rail voltage is high more, electromagnetic interference to railway landline along the line is big, only is applicable to open wire communication circuit that circuit is less or very easy that disturbed order wire is moved the railway that changes the path is along the line.

The BT power supply mode has two kinds: BT-rail mode and BT-return wire mode.BT-return wire mode better effects if wherein, its structure be as shown in Figure 2: except contact netting twine and rail, increased return wire; Insert a BT (twin coil) voltage transformer every about 1.5km-4km and form a BT section, the primary winding string of BT voltage transformer is on contact system T, the intensity coil string is on return wire F ', and the be separated by both sides of 1.5km-4km of return wire F ' link to each other with rail R by boosting cable HL respectively.The first side winding of BT has traction current arbitrarily

When flowing through, produce induced potential in its secondary side winding, thereby in inhaling stream C/LOOP (constituting), produce an induced current by return wire F ', winding, left and right sides boosting cable HL, rail R, because the BT voltage transformer is 1: 1 a voltage transformer, therefore this induced current is basic identical with the traction current size, direction is opposite, and therefore in this segment distance, basic no current flows through in the rail, rail potential is low, and the effect that suppresses communication countermeasures is fine.The shortcoming of BT mode is: increased the complexity of traction web frame, improved cost; Because sealing in of BT voltage transformer makes impedance of traction electric network become big, and loss increases, the feeding section length of traction transformer will reduce, and be about 3/4 of direct feeding system simultaneously.In addition, locomotive by the traction net seal in BT voltage transformer primary coil the time, can not directly pass through primary coil, and can only be by being parallel to the other BT segmentation that outage (insulation) gap is arranged of primary coil, thereby produce the spark gap phenomenon, both be unfavorable for the operation of big electric current locomotive such as high speed, heavy duty, and also can have produced and disturb communication.

The AT power supply mode: as shown in Figure 3, the mouth of traction transformer S links to each other with positive feeder F with the contact wire T of railway power supply net respectively.Be provided with 2: 1 autotransformer AT at the railway power supply net every about 10km, autotransformer is parallel between contact wire T and the positive feeder F, and the autotransformer neutral meets rail R.When locomotive was arranged in an AT section, to other AT sections between the traction substation, the working current of traction transformer flowed out along contact wire T in this AT section, flowed into along positive feeder F, and electric current is zero among the rail R; And in the AT at locomotive place section, still there is electric current to exist on the rail, and flow to last voltage transformer AT and back one voltage transformer AT respectively forward, backward at the locomotive position place, rail current fgn electromagnetic effect is cancelled out each other in this AT section, therefore still can suppress the interference to communication line.

Autotransformer in the AT power supply mode links to each other with the traction net with parallel way, locomotive (pantograph) need not the former limit by autotransformer, having overcome the BT power supply mode need be by the defective of BT segmentation generation spark gap, and traction loss is little, has also reduced the interference to communication; Simultaneously, current supply circuit voltage is increased to 55kV between the contact wire of AT power supply mode and positive feeder, the power supply voltage height, and because all AT voltage transformers are to be connected in parallel in the traction net, impedance of traction electric network is little, the online loss of voltage and energy loss are all little, and power supply distance is long, is about 170%～200% of direct feeding system.In a word, the AT power supply mode is a kind of mode of traction that is suitable for big electric current operation such as high speed, heavy duty, and when development high-speed overload railway, adopting high capacity AT power supply mode will be inexorable trend, but there is following deficiency in existing AT power supply mode:

One, the traction power transformation device of AT mode traction side voltage is 55kV or 2 * 27.5kV, and the traction transformer voltage class is 27.5kV in the substation of direct-furnish mode or BT mode, therefore, when transforming direct-furnish mode or BT mode tractive power supply system as the AT tractive power supply system, need to change the main equipment that comprises traction transformer, increased engineering quantity and equipment investment.

Two, if traction transformer time limit winding does not have mid-point tap, as Scott (Scott) wiring transformer, when constituting the AT electric power system, need set up autotransformer in the traction substation outlet, increased engineering quantity and equipment investment.

Three, use two kinds of AT power supply modes of current 55kV and 2 * 27.5kV the time, caused the different of traction substation equipment and main electrical scheme in the engineering design, therefore be not easy to the unification of design standard.

Four, because domestic AT segment distance is generally longer, the longlyest reach more than 20 kilometer, under the high-speed overload condition of service, if traction transformer is 55kV, the traction transformer coil volume is required high, and high power capacity, high voltage transformer manufacture difficulty are big, the cost height.

Summary of the invention

Purpose of the present invention just provides a kind of 27.5KV ac electrified railway AT tractive power supply system, and this system has the advantage of AT electric power system, and equipment investment is few, and quantities is little, and maintenance, maintenance are easily; And its transformation to existing direct-furnish and BT mode railway is easy, and it is convenient to implement; Help the development of high-speed overload railway.

The present invention realizes its goal of the invention, and the technical scheme that is adopted is, a kind of 27.5KV ac electrified railway AT tractive power supply system, and its composition is:

The output voltage of the traction transformer of traction substation is 27.5kV, and a mouth of traction transformer links to each other with rail, and another mouth links to each other with the positive feeder of railway dragging net;

It is 2: 1 autotransformer that railway dragging net is provided with a no-load voltage ratio every 10～20km, and an end of autotransformer links to each other with the railway contact wire, and mid point links to each other with rail, and the other end links to each other with the positive feeder of railway dragging net.

Compared with prior art, the invention has the beneficial effects as follows:

Because the voltage transformer outgoing side two ends of traction substation of the present invention link to each other with mid point (rail) with an end (positive feeder) of autotransformer respectively, rather than link to each other with the two ends of autotransformer, thereby adopt the voltage transformer of 27.5kv, obtain the voltage of 55KV by the boosting of autotransformer (positive feeder with contact line end) equally at its two ends.Simultaneously, the contact wire loop that autotransformer and contact wire, rail constitute, and the connection mode and the principle of work in the loop of autotransformer and positive feeder formation are identical with existing AT mode, thereby the present invention adopts the traction transformer of 27.5kv to realize that the AT mode of rail, contact wire, positive feeder powers.Therefore, the present invention has all advantages of existing AT power supply mode, and possesses following beneficial effect.

One, for newly built railway, original 55kV traction transformer or 2 * 27.5kV traction transformer are become the 27.5kV traction transformer, the voltage of traction transformer reduces half, has reduced construction costs, small investment.

Two, the mouth of traction transformer only need connect rail and positive feeder, and no longer links to each other with contact wire, and is easy to connect, also is convenient to daily attention and maintenance.

Three, because the traction transformer of existing direct-furnish mode or BT mode also is the 27.5KV voltage transformer, therefore, it is carried out that the traction power supply mode is connected or when transforming AT traction power supply mode of the present invention as, traction substation does not need to change traction transformer or increases autotransformer in the traction substation exit, engineering quantity and equipment investment have also been reduced, reduce transformation and construction cost, helped promotion and implementation of the present invention.

In a word, system architecture of the present invention is simple, and it is convenient to implement, and cost is low, is connected convenient with existing tractive power supply system, helps the development of the high-speed overload railway of China.

The invention will be further described below in conjunction with the drawings and specific embodiments.

Description of drawings

Fig. 1 is existing direct-furnish mode electric power system structural representation.

Fig. 2 is existing BT-return wire mode electric power system structural representation.

Fig. 3 is existing AT mode electric power system structural representation.

Fig. 4 is the structural representation of the embodiment of the invention.

The specific embodiment

Embodiment

Fig. 4 illustrates, and a kind of specific embodiment of the present invention is, a kind of 27.5KV ac electrified railway AT tractive power supply system, and its composition is:

The output voltage of the traction transformer S of traction substation is 27.5kV, and the mouth M of traction transformer S links to each other with rail R, and another mouth N links to each other with the positive feeder F of railway dragging net;

It is 2: 1 autotransformer AT that railway dragging net is provided with a no-load voltage ratio every 10～20km, and the end a of autotransformer AT links to each other with railway contact wire T, and mid point o links to each other with rail R, and other end b links to each other with the positive feeder F of railway dragging net.

Claims

1. 27.5KV ac electrified railway AT tractive power supply system, its composition is:

The output voltage of the traction transformer of traction substation (S) is 27.5kV, and a mouth (M) of traction transformer (S) links to each other with rail (R), and another mouth (N) links to each other with the positive feeder (F) of railway dragging net;

It is 2: 1 autotransformer (AT) that railway dragging net is provided with a no-load voltage ratio every 10～20km, one end (a) of autotransformer (AT) links to each other with railway contact wire (T), mid point (o) links to each other with rail (R), and the other end (b) links to each other with the positive feeder (F) of railway dragging net.