EP3580770A1

EP3580770A1 - Air-cooled dry-type transformer

Info

Publication number: EP3580770A1
Application number: EP18708595.6A
Authority: EP
Inventors: Jens Tepper; Yong Wang
Original assignee: ABB Schweiz AG
Current assignee: Hitachi Energy Ltd
Priority date: 2017-02-08
Filing date: 2018-02-08
Publication date: 2019-12-18
Anticipated expiration: 2038-02-08
Also published as: CN110249397A; PL3580770T3; US12014856B2; ES2946190T3; DE102017102436A1; EP3580770B1; US20190362879A1; WO2018146196A1; CN117766264A; DK3580770T3; KR102518571B1; KR20190112061A

Abstract

The invention relates to an air-cooled dry-type transformer (1) comprising a core (10) provided with a branch (11); a winding body (14) arranged about the branch (11); a cooling channel (25) extending in the direction of the longitudinal axis of the winding body (14), the cooling channel being arranged between an inner part (15) of the winding body (14) and an outer part (20) of the winding body (14), the cooling channel (25) having on both ends openings (40, 42) and an essentially annular shaped cross-section having a round, oval or polygonal basic shape; at least one ring ventilator (30, 30a, 30b, 30c) comprising a ring (32) and a blower (34), wherein the blower (34) is designed to suction air and to blow the air from the ring (32) along a longitudinal axis of the ring (32), wherein an air flow (31) is generated. The ring ventilator (30, 30a, 30b, 30c) is dimensioned and mounted such that the air flow (31) generates a cool air flow (35) in the cooling channel (25). The invention further relates to a power device with air cooling and a cooling method using a ring ventilator.

Description

Drying transformer with air cooling

Technical area

The present disclosure relates to methods and apparatus for cooling electrical power devices, particularly power transformers. In particular, it relates to methods and systems for cooling dry-type transformers by means of ring fans, in particular of dry-type transformers in non-ventilated housings with forced air cooling within the housing.

Background of the invention

Various techniques have been proposed for improving the cooling of dry-type transformers. These include cooling air channels within the core to improve heat dissipation. In general, a positive pressure is generated in the lower region of the housing with a fan, while a negative pressure can be generated by extraction of the air in the upper region of the housing. In this way, an air flow is generated, which flows from bottom to top. However, a large amount of air does not flow as desired through the cooling channels of the windings, but undesirably around the outside of the coils. One of the reasons for this is that the cross-sectional area of the cooling channels within the windings is usually much smaller than the cross-sectional area between the housing wall and the coils.

This can generally be avoided by the following methods: First, the fan can be placed under the coils to blow the air into the cooling channels. In addition, air guide plates can be arranged in the immediate vicinity of the coils, in order to make the flow resistance of the cooling channels smaller than the flow resistance of the region outside the coils in this way. In this case, to blow the air into the coils, a relatively powerful fan is required, with a large part of the air still flowing around the coils. In addition, so that they are sufficiently effective, the baffles are adapted to the contours of the coils individually, which involves a considerable amount of work. In addition, because the air guide plates produce significant additional resistance, the ventilation system operates with a lower overall airflow. ciency. Overall, it is also true that with improved cooling with conventional fans much noise is created, especially by the rotating blades.

Against this background, there is a need for the present invention.

Summary of the invention

The object of the invention is achieved by an air-cooled dry type transformer according to claim 1, a transformer cooling system according to claim 7, a method for cooling a dry type transformer according to claim 8, a use of a ring fan according to claim 9, and an electric power device with air cooling according to claim 1

In a first aspect of the invention, an air cooled dry type transformer is provided. It comprises a core comprising a leg; a winding body disposed about the leg; a cooling passage extending in the direction of the longitudinal axis of the winding body and disposed between an inner part of the winding body and an outer part of the winding body, the cooling passage having openings at both ends thereof and having a substantially annular cross-section of a round, oval or polygonal basic shape; at least one annular fan comprising a ring and a fan, the fan being arranged to draw in air and to blow the air out of the ring along a longitudinal axis of the ring, producing an airflow; wherein the ring fan is dimensioned and arranged such that the air flow generates a cooling air flow in the cooling channel.

The cooling passages described in this disclosure generally include all types of passages that may be utilized in accordance with aspects and embodiments for passing cooling air or cooling gas through a dry type transformer. These may, for example, also be channels originally intended for the purpose of dielectric isolation or control of the field. For example, the cooling channels described herein may be provided between a core and a winding, or within a winding, between different windings, or on the outside of the winding body. In a second aspect of the invention, a transformer cooling system is provided. It comprises a dry-type transformer according to the first aspect, a housing for the dry-type transformer; and a heat exchanger adapted to dissipate heat from the housing; wherein the cooling air flow generated by the at least one annular fan meets after passing through the cooling channel of the dry-type transformer to the heat exchanger and is cooled there.

In a third aspect, a method for cooling a dry-type transformer is provided. The method includes providing a ring fan and a dry transformer, directing a cooling air flow of the ring fan to a mating, substantially annular opening of a cooling passage of the dry transformer.

In a further aspect, there is proposed a use of a ring fan for cooling an electric power device, wherein a directed substantially annular cooling air flow of a ring fan is directed to a mating opening of a cooling channel of the electric power device.

In another aspect, an electric power device with air cooling is proposed. The apparatus comprises an electric power device having a cooling passage with at least one substantially annular opening, a ring fan comprising a ring and a fan, the fan being arranged to draw in air and the air directed along a longitudinal axis of the ring to blow out, wherein a cooling air flow is generated in the cooling channel.

Further features and advantages of the present invention are presented in the following detailed description of preferred embodiments of the system.

Brief description of the figures

Other features and advantages of the present invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the appended drawings. Showing: Fig. 1 shows a cross section through a dry-type transformer according to embodiments, as well as a top view of the transformer;

FIG. 2 shows a cross section through a dry-type transformer according to further embodiments; FIG.

Fig. 3 shows a ring fan according to embodiments;

4 shows a cross section through a dry-type transformer according to further embodiments;

5 shows a cross section through a dry-type transformer according to further embodiments;

6 shows a cross section through a cooling system for a dry-type transformer according to embodiments;

Fig. 7 shows a plan view of a dry-type transformer according to others

Embodiments.

Detailed description

Although preferred embodiments are described, the scope of the invention is not limited to the illustrated embodiments, but also includes embodiments obvious to those skilled in the art.

In general, embodiments of the invention relate to dry-type transformers which are cooled by at least one electrically driven annular fan. A ring fan, as used in this disclosure, includes an annular housing from which flows an annular stream of air in the axial direction of the ring. In the middle of the housing there is a central opening through which, in embodiments, a leg of the transformer core runs or is located therein. Generally, in this disclosure, the term "ring fan" is to be considered as corresponding to the previous definition, including the variants described below.

A ring fan may have an annular housing as a stator, with a likewise annular rotor therein, are mounted on the blades, which are visible to the outside as in a conventional fan. In another, herein In embodiments, the ring fan may be a bladeless fan in embodiments. A bladeless fan blows the air out of a ring without any direct involvement of rotating blades, or they are typically encapsulated in an extra housing. The air is sucked through an internally installed rotor in the base or on the side of the bladeless fan through holes located therein, and passed into a circumferential cavity of a ring. Subsequently, the air is accelerated through a slot, which is preferably provided on an inner side of the ring.

This results in an air jet that is shaped according to the geometry of the ring. To channel the direction of the jet of air, the jet is blown over a slope that is shaped approximately like a wing. At the same time, the surrounding air can be sucked in as a side stream, whereby the total air flow from the fan is amplified. The present invention relates to the use of bladeless fans for dry-type transformers, and more generally to the cooling of other types of electrical appliances or power appliances. Various measures ensure that a large part of the ventilated air is blown directly through cooling channels of the dry-type transformer and does not flow past the outside of the coils / windings. In the following, it is generally assumed that the core of the transformer is vertical with respect to the earth's surface. This is favorable in terms of flow, since the air flow generated by the fan is supported or intensified by the convection of the heated air. In embodiments, however, the core may also have other orientations, such as horizontal to the earth's surface, so that the cooling air flow flows horizontally. In the following, however, it is assumed that technically usual vertical cores or legs are used.

In this case, embodiments relate in particular to the following cases: Typically, the transformer is cooled by an air flow directed from the bottom up, which is generated by a ring or bladeless fan arranged in the lower region of the windings or directly under the windings. Alternatively, the air flow directed from the bottom to the top can also be generated by a ring or bladeless fan arranged in the upper region of the windings. Finally, the air flow can be through both in the lower, as well as in the upper area the windings arranged ring or bladeless fans are generated, that is, by a combination of the above two cases. When the windings are separated from one another in the vertical direction, ie along the longitudinal axis of the core, a fan may also be installed between the upper coil and the lower coil (in addition to the above-described variants, or individually). For three separate windings on three legs of a three-phase dry-type transformer, the above variants may be made individually for each leg, or a single fan with a ring may be used, which ring is not round but oblong and all three windings are on the covering three thighs.

Embodiments have the following advantages over conventional ventilation techniques with conventional fans. Firstly, the initially described air guide plates and their holding device or connections can be completely eliminated. In addition, in embodiments, such as through a heat exchanger, cooled air can be passed directly to the fan through a pipe and then blown into the cooling channels. This avoids unnecessary heat exchange between the cooling air and the environment outside the windings. Therefore, the cooled air in the supply pipe to the ring or bladeless fan remains cool. Much of the accelerated by the fan air flows directly into and through the cooling channels in the windings, which is achieved at the same time with little or reduced structural complexity. In addition, especially the bladeless fans operate with a low noise level due to the absence of open, rotating blades as in a conventional fan or blower.

1 shows an air-cooled dry-type transformer 1 according to embodiments in cross-section. This comprises a core 10 with a leg 11 and a winding body 14 arranged around the core 10 or around the leg 11. The winding body 14 may have a plurality of windings or winding parts. Between an inner part 15 of the winding body 14 and an outer part 20 of the winding body 14 is a cooling channel 25. This has at its two ends, typically below and above with a vertical core 10 and leg 1 1, two openings 40, 42nd Der Cooling channel 25 typically but not necessarily has a substantially annular or annular cross-section. In the ren part of Fig. 1 is a plan view from above, wherein the ring 32 is shown in black. The dry-type transformer 1 may also have a plurality of legs 11, approximately two or three.

A ring fan 30 arranged under the dry-type transformer 1 comprises a ring 32 and a fan 34 (see also FIG. 3). The blower 34 is configured to draw in ambient air (in embodiments, for example, the air may be supplied through a pipe) and to blow the air out of a slot 33 in the ring 32 in a directional manner along a longitudinal axis of the ring 32. In this case, a cooling air flow 35 is generated. The ring fan 30 is dimensioned and arranged so that it generates an annular cooling air flow 35 which fits geometrically to the dimensions of the cooling channel 25.

The cooling air flow 35 corresponds in its cross-sectional profile and in its dimensions substantially the cross-sectional profile and the dimensions of one of the openings 40, 42, so typically also the dimensions of the cooling air passage 25. The cooling passage 25 typically has an inner cooling passage diameter d1 and an outer cooling passage Diameter d2 on. These are substantially identical to the inner air flow diameter dksl and the outer air flow diameter dks2 of the cooling air flow 31.

2, an embodiment is shown in which a ring fan 30b is disposed above the winding body 14. That is, the cooling air flow 35 is generated by sucking the air from the cooling air passage 25.

In Fig. 3 an exemplary, non-limiting example of a ring fan 30, 30a, 30b in the form of a blade-less fan is shown. The blown out of the slot 33 in the ring 32 cooling air flow 35 is symbolically represented by arrows. In addition, on the right side, the supply of the cooling air to the blower 34 is shown. In exemplary embodiments, the cooling air flow is conducted or guided through a pipe or a line to the blower 34.

FIG. 4 shows a further embodiment in which the annular or bladed fan does not act on or around the core 10 as in the other examples, but outside and above the dry-type transformer 1 and the core 10. is ordered. In this case, the fan may for example be attached to an upper side or ceiling of a housing, that is without direct contact with the transformer 1 itself.

FIG. 5 shows a dry-type transformer 1 according to exemplary embodiments, which represents a combination of the variants from FIGS. 1 and 2. In addition, here the windings are divided on the core or leg, so that between the winding segments 70, 75, a further ring or bladeless fan 30 c is arranged. That is, the fan 30c is arranged between two winding segments 70, 75 arranged separately in the longitudinal direction of the core 10. For one of the winding segments 70 he works in the blowing operation, for the other winding segment 75 in the suction mode. In other embodiments, with such a transformer configuration, only the central or leaflet fan 30c may be used.

FIG. 6 shows a transformer cooling system 100 with a dry-type transformer 1 according to one of the embodiments described above. The dry-type transformer 1 is located in a (substantially or completely closed) housing 50. The cooling air of the cooling-air stream 35, after passing through the cooling channel 25, is led into a heat exchanger 60. This serves to remove the waste heat from the housing 100 out, for example, to the ambient air, or even to a cooling circuit with a fluid such. Water.

The heated by the dry-type transformer 1 cooling air flow 35 is thus passed after passage through the cooling passage 25 of the dry-type transformer 1 in the heat exchanger 60 and cooled there. The cooled air stream is then sucked back through the blower 34 of the (or more) bladeless fan 30a by means of a tube 36. Thus, there is a closed cooling air circuit.

Fig. 7 shows from below a dry-type transformer 1 with three legs 1 1, such as a three-phase transformer. In this case, only a bladeless fan 30d is used, whose ring 32b is made elongated or elongated in order to cover all three winding bodies 14. Alternatively, one or more dedicated fans may also be provided for each leg 1 1 or winding body 14, as described for example with reference to FIGS. 1 and 5. In general, the ringless fans 30, 30a, 30b, 30c described herein may be used according to embodiments for cooling all types of electric power devices 2, such as electric motors, generators, power semiconductor devices, etc. the power device 2 is equipped with a matching to the geometry of the cooling air flow opening 40, 42 of a cooling channel 25. The here elongated or elongated ring 32a of the bladeless fan can also take other forms than circular, such as elliptical, square or rectangular.

Claims

claims

1 . An air-cooled dry-type transformer (1) comprising:

a core (10) comprising a limb (11),

a winding body (14) arranged around the leg (11);

a cooling passage (25) extending in the direction of the longitudinal axis of the winding body (14), which is arranged between an inner part (15) of the winding body (14) and an outer part (20) of the winding body (14),

wherein the cooling channel (25) at its two ends openings (40, 42) and has a substantially annular cross-section with a round, oval or polygonal basic shape;

at least one annular fan (30, 30a, 30b, 30c) comprising a ring (32) and a fan (34), the fan (34) being arranged to draw in air and direct the air out of the ring (32) a longitudinal axis of the ring (32) to blow out, wherein an air flow (31) is generated;

wherein the ring fan (30, 30a, 30b, 30c) is dimensioned and arranged such that the air flow (31) generates a cooling air flow (35) in the cooling channel (25).

2. Drying transformer (1) according to claim 1, wherein the air flow (31) in his

Cross-sectional profile substantially corresponds to the cross-sectional profile of at least one of the openings (40, 42) of the cooling channel (25).

A dry type transformer (1) according to claim 1 or 2, wherein the cooling passage (25) has an inner cooling passage diameter d1 and an outer cooling passage diameter d2 substantially identical to the inner air flow diameter dksl and the outer air flow diameter dks2 of the airflow (31).

4. Drying transformer according to one of the preceding claims, comprising:

a. a first annular fan (30a) blowing air into the cooling passage (25) through a first one of the openings (40, 42), and / or

b. a second annular fan (30b) which sucks air from the cooling passage (25) through a second one of the openings (40, 42).

5. Drying transformer according to one of the preceding claims, comprising at least one further annular fan (30c) between two in the longitudinal direction of the leg (1 1) separately arranged winding body segments (70, 75), each having an inner part (15, 15a) of the winding body segment (70, 75) and an outer part (20, 20a) of the winding body segment (70, 75) is arranged on the leg (1 1), and for one of the winding body segments (70 , 75) in the blowing operation, for the other winding body segment (70, 75) operates in the suction mode.

6. dry-type transformer (1) according to one of the preceding claims, the

Three-phase transformer and three legs (1 1) with three winding bodies pern (14) according to any one of the preceding claims, wherein either:

- On each leg (1 1) of the transformer, a ring fan (30, 30 a, 30 b, 30 c) is mounted, or

- A common annular fan (30d) is provided, the elongated shaped ring (32a) extends over all three winding body (14) and blows air in each case in the cooling channels (25) of the individual winding body (14).

7. A transformer cooling system (100) comprising: a. a dry-type transformer (1) according to one of the preceding claims; and

b. a housing (50) for the dry-type transformer (1); and

c. a heat exchanger (60) adapted to dissipate heat from the housing; wherein the cooling air flow (35) generated by the at least one annular fan (30, 30a, 30b, 30c) after passing through the cooling channel (25) of the dry transformer (1) on the heat exchanger (60) meets and is cooled there.

8. A method of cooling a dry-type transformer (1), comprising:

Providing a ring fan (30, 30a, 30b, 30c) and a dry-type transformer (1), - directing a cooling air flow (31) of the annular fan on a suitably shaped, substantially annular opening (40, 42) of a cooling channel (25) of the dry-type transformer (1).

Use of a ring fan (30, 30a, 30b, 30c) for cooling an electric power device (2), wherein a directed, substantially annular cooling air flow (35) of a ring fan (30, 30a, 30b, 30c ) is directed to a matching opening (40, 42) of a cooling passage (25) of the electric power device (2).

10. Use according to claim 8, wherein the electrical power device

(2) is a dry-type transformer (1).

1 1. An electric power device (2) with air cooling, comprising

- An electrical power device (2) with a cooling channel (25) having at least one, substantially annular, opening (40, 42),

a ring fan (30, 30a, 30b, 30c) comprising a ring (32) and a fan (34), the fan (34) being arranged to suck in air and direct the air along a longitudinal axis of the ring (32 ), wherein a cooling air flow (35) is generated in the cooling passage (25).