CN2607647Y

CN2607647Y - Transformer for power station

Info

Publication number: CN2607647Y
Application number: CN 03220139
Authority: CN
Inventors: 罗明览; 雷龙武; 王劲军; 罗湘梅
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-02-26
Filing date: 2003-02-26
Publication date: 2004-03-24
Anticipated expiration: 2013-02-26

Abstract

The utility model relates to a transformer, in particular to a transformer used in the generating plants and consists of a first winding and a second winding. The first winding is connected with the electric network through a high-voltage switch. The key structural points are that the transformer is also composed of a third winding; the first winding uses a Y-connection of a primary coil;the second winding uses a Y-connection method of a secondary coil; the third winding uses a delta connection of a secondary coil; a neutral point of the first winding is connected with a single-phase grounding compensating unit; and a triphase terminal of the second winding is connected with the power supply electric network. The utility model has the advantages that the power supply function of the transformers and the compensation and detection function of the grounding transformers in the generating plant are integrated by using the three-winding transformer, thus avoiding a high-voltage switch and a set of a double-winding transformer and required only one storage space, namely simplifying the wiring, reducing the investment and saving the space; also avoiding the loss resulting in the idle running of the grounding transformer so as to save the operation cost.

Description

The power station transformer

Technical field

The utility model relates to a kind of transformer, particularly a kind of power station transformer.

Background technology

The power station includes a station transformer with transformer in the prior art, promptly be used for power supply, it includes first winding and second winding, the two is that (first winding is a delta connection to D-y double winding connection, second winding is a star connection), wherein first winding is connected with electrical network, and the triple line of second winding connects supply network, neutral ground.Owing in the electrical network that first winding is connect single phase ground fault can take place, so need to increase a grounding transformer, be used for single-phase lost territory and detect compensation, its double winding adopts Z-shaped double winding connection, two transformers all are connected in the electrical network of electric power conveying by a high-voltage switch gear, and take a space in transformer station separately.Its weak point is: 1, equipment investment height, and two transformers respectively need a high-voltage switch gear and relevant protection equipment; 2, take up room greatly, the enough big space layout with satisfied two transformers need be provided; 3, grounding transformer only comes into operation when single phase ground fault takes place in short-term, and all the other times then are in the no-load running state, the no-load loss and the grounding transformer zero load occurs now and then, thus cause economic loss.

Invention constitutes

The purpose of this utility model be to overcome weak point of the prior art and provide a kind of equipment investment low, take up room little, and can reduce no-load loss and reduce the power station transformer of economic loss.

The purpose of this utility model can realize by following approach:

The power station transformer, comprise first winding and second winding, first winding is connected with electrical network by a high-voltage switch gear, its structural feature is, also includes the tertiary winding, first winding circle star connection of serving as theme, second winding is the secondary coil star connection, the tertiary winding is the secondary coil delta connection, and the neutral point of first winding is connected with a kind of single-phase earthing compensation arrangement, and the second winding three-phase end is electrically connected with supply network.

Because the tertiary winding is a delta connection; it can produce zero-sequence current; after so the neutral point of first winding connects compensation arrangement; can be grounded the compensation detection effect of transformer: when electrical network generation single phase ground fault that first winding is connect; the delta connection of the tertiary winding can provide the path of short circuit for zero-sequence current and offset current, makes the zero-sequenceprotection action message; realize the effect of detection failure phase line, meanwhile also can not influence of the power supply of second winding supply network.

Because the station is different with the grounding transformer effect with transformer, and the two winding transformer structure is simple in structure than three-winding transformer, therefore, those skilled in the art consider from technical standpoint, stand and all adopt two winding transformer with transformer and grounding transformer, and independent distribution separately, and do not consider to use the function of use of the compatible two kinds of transformers of three-winding transformer, in the course of time, those skilled in the art all think no matter be at technical elements, still in other respects, three-winding transformer is not suitable for power station transformer occasion, like this, produced this ubiquitous understanding that departs from objective fact, this technology prejudice is guiding people not consider the application possibility of three-winding transformer from other angles for a long time.And inventor of the present utility model acts in a diametrically opposite way just, the technological means that has adopted people to give up by this technology prejudice, thereby solved technical problem, that is: adopted three-winding transformer as the power station transformer, make it to have simultaneously the function of station with transformer and grounding transformer, like this, just only need a high-voltage switch gear and a cover three-winding transformer, can combine the effect of station, thereby reduce or remit a high-voltage switch gear and a cover two winding transformer with transformer and grounding transformer, and only need a space to hold, promptly simplify wiring, reduce investment, saved expense, have economy, saved the space again; The ground connection transformation is not when incision moves, because the station is in successive work with transformer, so operating cost has been saved in the loss that can avoid the no-load running of ground connection transformation to bring simultaneously.

The utility model can also further be specially:

Connection between three windings can have multiple choices:

It between first winding, second winding and the tertiary winding Y-y-d three-winding transformer connection;

It between first winding, the tertiary winding and second winding Y-d-y three-winding transformer connection;

For guaranteeing power supply safety, the neutral point of its second winding is answered ground connection.

The single-phase earthing compensation arrangement can further be specially:

The single-phase earthing compensation arrangement includes arc suppression coil loop, resistance loop and high and low voltage switch device, wherein arc suppression coil loop and resistance loop and be unified into connection circuit in the lump, the one end is connected in the neutral point of first winding, other end ground connection, the high and low voltage switch device then is electrically connected with resistance loop;

The high and low voltage switch device comprises low-voltage control switch and transformer, resistance loop is connected with low-voltage control switch, and be connected the secondary side of transformer, the secondary side winding of transformer has a plurality of terminals, there are a plurality of control switchs and a plurality of terminals to connect one to one, the arc suppression coil loop is attempted by the secondary side of transformer, and is electrically connected with control switch.

Like this, because in the system, the size of fault current is indefinite, need inject inductance current according to the fault current size, prevent undercompensation or overcompensation, therefore be attempted by the control switch of secondary side and being electrically connected of arc suppression coil, both can regulate the size of inductive current automatically by adjusting, guarantee safety operation again, played compensating action.Can pass through the cut-out and the access of the secondary side controlling resistance of low-pressure end again; to increase instantaneous current in resistance property in the primary side loop; and the zero-sequenceprotection in the assurance electrical network has enough big immediate current to make it action; thereby play the effect of detection line fault; so this single-phase earthing compensation arrangement possesses the effect that the detection line fault is arranged, can be described as single-phase earthing compensation checkout gear.

In sum, the utility model comes the combined station power supply function of transformer and the detection compensating action of grounding transformer by adopting three-winding transformer, thereby reduce or remit a high-voltage switch gear and a cover two winding transformer, and only need a space to hold, promptly simplify wiring, reduce investment, saved expense, have economy, saved the space again; First winding is not when the incision compensation detects operation, because three-winding transformer is in powered operation continuously, so operating cost has been saved in the loss that can avoid the no-load running of ground connection transformation to bring simultaneously.

Description of drawings

Figure 1 shows that the electrical block diagram of the utility model most preferred embodiment;

Figure 2 shows that the electrical block diagram of the utility model checkout gear.

Below we are further described the utility model in conjunction with the embodiments.

Specific embodiment

Most preferred embodiment:

With reference to accompanying drawing 1, the power station transformer, comprise first winding 1, second winding 2 and the tertiary winding 3, first winding 1 is connected with electrical network by a high-voltage switch gear 4, high-voltage switch gear 4 is a kind of primary cut-out, the first winding 1 circle star connection of serving as theme, the tertiary winding 3 is the secondary coil delta connection, and second winding 2 is the secondary coil star connection; First winding 1, the tertiary winding 3 and second winding 2 are Y-d-y three-winding transformer connection; The neutral point of first winding 1 is connected with single-phase earthing compensation checkout gear 5, and the three phase terminals of second winding 2 is electrically connected with supply network 6, neutral ground.

With reference to accompanying drawing 2, single-phase earthing compensation checkout gear 5 includes arc suppression coil loop 51, resistance loop 52, low-voltage control switch 53 and transformer 54, wherein arc suppression coil loop 51 is with resistance loop 52 and be unified into connection circuit in the lump, the one end is connected in the neutral point of first winding 1, other end ground connection, resistance loop 52 is connected with low-voltage control switch 53, and be connected the secondary side of transformer 54, the secondary side winding of transformer 54 has 5 terminals, there are 5 control switchs 55 and these terminals to connect one to one, arc suppression coil loop 51 is attempted by the secondary side of transformer 54, and is electrically connected with control switch 55.

It is same as the prior art that the utility model is not stated part.

Claims

1, power station transformer, comprise first winding (1) and second winding (2), first winding (1) is connected with electrical network by a high-voltage switch gear (4), it is characterized in that, also include the tertiary winding (3), first winding (1) the circle star connection of serving as theme, second winding (2) is the secondary coil star connection, the tertiary winding (3) is the secondary coil delta connection, the neutral point of first winding (1) is connected with a kind of single-phase earthing compensation arrangement (5), and the three phase terminals of second winding (2) is electrically connected with supply network (6).

2, power station according to claim 1 transformer is characterized in that, is Y-y-d three-winding transformer connection between first winding (1), second winding (2) and the tertiary winding (3).

3, power station according to claim 1 transformer is characterized in that, is Y-d-y three-winding transformer connection between first winding (1), the tertiary winding (3) and second winding (2).

4, power station according to claim 1 transformer is characterized in that the neutral ground of second winding (2).

5, power station according to claim 1 transformer, it is characterized in that, single-phase earthing compensation arrangement (5) includes arc suppression coil loop (51), resistance loop (52) and high and low voltage switch device (53), wherein arc suppression coil loop (51) and resistance loop (52) and be unified into connection circuit in the lump, the one end is connected in the neutral point of first winding (1), other end ground connection, high and low voltage switch device (53) then are electrically connected with resistance loop (52).

6, power station according to claim 3 transformer, it is characterized in that, high and low voltage switch device (53) comprises low-voltage control switch and transformer, resistance loop (52) is connected with low-voltage control switch, and being connected the secondary side of transformer, the secondary side winding of transformer has a plurality of terminals, has a plurality of control switchs and a plurality of terminals to connect one to one, arc suppression coil loop (51) is attempted by the secondary side of transformer, and is electrically connected with control switch.