Apparatus for transforming and rectifying a multiphase voltage

Abstract

The present application discloses an apparatus for transforming and rectifying a multiphase voltage, in particular a three-phase voltage, comprising a multiphase transformer (17) comprising a hollow central region (22), a voltage rectifier circuit (18) connected to the transformer, and a fan (20). The voltage rectifier circuit comprises at least three heat sink units (18a, 18b, 18c) forming straight prisms with a regular polygonal cross-section having a hollow central region (23), the transformer, the voltage rectifier circuit and the fan being positioned such that at least some of the airflow generated by the fan flows through the hollow central region of the rectifier in order to immerse the transformer.

Description

TECHNICAL FIELD

[0001] The present invention relates to energy conversion equipment and more particularly to equipment for transforming and rectifying polyphase voltages.

[0002] The present invention more particularly relates to an equipment for transforming and rectifying voltages, which is installed on board of an aircraft and which is known by the person skilled in the art as a transformer rectifier unit (initials TRU). BACKGROUND

[0003] Figures 1 and 2 schematically depict an equipment 1 for transforming and rectifying three-phase voltages.

[0004] The equipment 1 comprises a rectification circuit comprising rectification diodes 9 and a heat dissipation radiator 8, and a three-phase transformer 3 comprising a magnetic circuit 4 and three windings 5, 6 and 7. The whole assembly is installed in a casing 2 provided with a bottom plate P.

[0005] The heat dissipation radiator 8 is provided with fins 10 and dissipates the heat generated by the diodes 9.

[0006] The equipment 1 also comprises a fan 11 attached to one face 2a of the casing 2 comprising a front opening. This fan is able to generate a cooling airflow flowing into the casing 2 so that some of the airflow flows through a cooling circuit between the fins 10 of the cooling radiator 8 in order to cool in particular the diodes 9.

[0007] However, although this equipment offers advantages, the components of this equipment are not perfectly satisfactorily cooled and there remains a need to further reduce the weight and the bulk of said equipment.

[0008] It is therefore an object of the present invention to improve the cooling of an equipment for transforming and rectifying polyphase voltages according to the prior art, without increasing the bulk or the weight of the equipment. SUMMARY

[0009] In view of the above, the present invention proposes an equipment for transforming and rectifying polyphase voltages, said equipment comprising a polyphase, in particular three-phase, transformer having a hollow central zone, a voltage rectification circuit connected to said transformer and a fan.

[0010] Said voltage rectification circuit comprises at least three heat dissipation units forming a straight prism having a regular polygonal section with a hollow central zone. The transformer, the voltage rectification circuit and the fan are positioned so that at least some of the airflow generated by the fan flows through the hollow central zone of the rectifier in order to immerse the transformer.

[0011] According to another feature, the axis of the fan, the rectifier circuit and the transformer are parallel to, or even aligned with, the same axis, so that the air flow is guided by the rectifier circuit.

[0012] Advantageously, the peripheral face of the transformer and the peripheral face of the rectifier circuit are located in parallel planes, or even in coplanar planes.

[0013] Preferably, a first diffuser is placed between the fan and the rectifier circuit, a first end of the diffuser abutting the fan and a second end of the diffuser being in contact with the rectifier circuit, the cross sections of the first and second ends of the diffuser being substantially identical to the cross sections of the fan and the rectifier circuit, respectively, so as to direct the air flow into the rectifier circuit.

[0014] Preferably, the fan comprises an active zone for blowing the air flow and a dead zone not used for blowing said air flow, the device further comprising a guiding device whose dimensions are substantially equal to the dimensions of the dead zone, so as to direct the air flow towards the rectifier circuit around the dead zone.

[0015] According to another feature, the transformer and rectifier device further comprises a second diffuser arranged around the transformer, so as to direct at least some of the air flow that does not flow through the hollow central zone of the rectifier and that does not flow through the hollow central zone of the transformer, around the transformer.

[0016] According to another feature, the at least one heat dissipation unit comprises a heat dissipation radiator whose one face comprises heat dissipation fins, in particular arranged in the hollow central zone of the rectifier circuit, and a rectifier diode arranged on the face opposite the face comprising the heat dissipation fins.

[0017] Advantageously, the multiphase transformer comprises a magnetic circuit forming a straight prism having a regular polygonal cross section, in particular a straight prism based on a triangle, a straight prism based on a star or a straight prism based on a hexagon.

[0018] Preferably, the magnetic circuit comprises a plurality of magnetic elements passing through one or more coils, each magnetic element forming a closed loop substantially passing through the edges of the straight prism.

[0019] Advantageously, the number of magnetic elements is a multiple of three.

[0020] According to a first embodiment, the device for transforming and rectifying a multiphase voltage further comprises an air flow outlet aperture arranged so that the air flow generated by the fan flows through the rectifier circuit and the transformer before exiting through said aperture.

[0021] According to another aspect, there is proposed an aircraft comprising at least one device for transforming and rectifying a multiphase voltage, such as described above, and a housing incorporating said device. BRIEF DESCRIPTION OF DRAWINGS

[0022] Other objects, features and advantages of the present application will become apparent from the following description, given by way of non-limiting example only, and with reference to the accompanying drawings, in which:

[0023] Figures 1 and 2, already mentioned, show schematically a device for transforming and rectifying a polyphase voltage according to the prior art;

[0024] Figure 3 , 4 Figures 5 and 5a show a first embodiment of a device for transforming and rectifying a polyphase voltage according to the present application;

[0025] Figure 6 Figures 6 and 6a show a second embodiment of a device for transforming and rectifying a polyphase voltage according to the present application;

[0026] Figure 7 Figures 7 and 7a show another embodiment of a device incorporated in a housing according to the present application;

[0027] Figure 8 Figures 8 and 8a show a second embodiment of a polyphase transformer;

[0028] Figure 9 Figures 9 and 9a show a third embodiment of a polyphase transformer;

[0029] Figure 10 Figures 10 and 10a show an aircraft comprising a device for transforming and rectifying a polyphase voltage. DETAILED DESCRIPTION

[0030] Reference is made to Figures 5 and 5a, which show a first embodiment of a device 15 for transforming and rectifying a polyphase voltage. The device is placed in a housing 16, the dimensions of which are the same as or smaller than the dimensions of the housing 2 according to the prior art. Figure 3 , 4 and 5. The device is placed in a housing 16, the dimensions of which are the same as or smaller than the dimensions of the housing 2 according to the prior art.

[0031] The device 15 comprises a polyphase transformer 17 comprising a hollow central region, and a three-phase voltage rectification circuit 18 electrically connected to the transformer.

[0032] In the following, the transformer 17 is a three-phase transformer also comprising a hollow central region 22.

[0033] According to a first preferred embodiment, the three-phase transformer 17 comprises a magnetic circuit forming a straight prism with a regular polygonal section. The number of sides of the polygonal section of the straight prism is a multiple of three. As shown, the magnetic circuit can comprise a triangle-based straight prism.

[0034] The magnetic circuit comprises a plurality of magnetic elements passing through one or more coils, each magnetic element forming a closed loop passing substantially through the edges of the prism.

[0035] The number of magnetic elements is a multiple of three.

[0036] The voltage rectification circuit 18 is formed on the basis of diodes D. As a variant, the rectifier function can be implemented by means of transistors or thyristors or by means of other semiconductor components.

[0037] As shown, the rectification circuit comprises rectification modules each comprising a bridge of rectifier elements, here four diodes, mounted on a heat sink unit. The rectification circuit comprises, for example, identical heat sink units 18a, 18b and 18c arranged to form a straight prism comprising a hollow central zone 23 through which a cooling air flow passes.

[0038] As shown in Figure 4 and 5 , the rectification circuit comprises three heat sink units 18a, 18b and 18c arranged to form a straight prism comprising a hollow central zone 23, in particular a straight prism having an equilateral triangular cross section.

[0039] As a variant, in the embodiment of Figure 5a , the three-phase voltage rectification circuit 32 comprises six identical heat sink units 32a, 32b, 32c, 32d, 32e and 32f arranged to form a straight prism having a regular hexagonal cross section. The device 15 comprises a rectification circuit 32 comprising a hollow central zone 33 whose outer shape is substantially hexagonal and whose inner shape is substantially circular.

[0040] Each unit 18a, 18b and 18c comprises fins 25 distributed on the face of the heat sink radiator opposite the rectification diodes D. Each unit can have the same number of rectification diodes.

[0041] Each fin 25 conducts some heat from the heat sink. The fins 25 each face the air flow generated by the fan 20 for cooling purposes. In other words, the fins 25 are arranged in the hollow central zone 23 of the rectification circuit 18.

[0042] According to another embodiment (not shown), the rectification diodes D are arranged inside the hollow central zone 23 and the fins 25 of the heat sink 24 are arranged on the face opposite the hollow central zone.

[0043] The fins 25 can be distributed uniformly on the heat sink 24 in order to increase the heat exchange area.

[0044] The fins can be obtained by extrusion and machining.

[0045] The profile of each fin can be isosceles trapezoidal, the smallest base of which is free / unconstrained, thus facilitating the extrusion operation.

[0046] As a variant, the profile of each fin is rectangular or corrugated.

[0047] The fan 20 is attached to the first side 16a of the housing 16, preferably to the outer side of the housing 16. In the zone for mounting the fan 20, the housing is provided with an axial opening O, preferably coaxial with the transformer 17 and the rectifier circuit 18, so that the air flow generated by the fan enters the housing 16.

[0048] On the opposite side 16b, the housing comprises air outlet holes 16c which are arranged and dimensioned collectively so that the air flow generated by the fan 20 passes through the rectifier circuit 18 and the transformer 17 before exiting the housing through the holes 16c.

[0049] A first diffuser 21 of the air flow can be attached to the inner surface on the side 16a of the housing so that the air flow is directed into the housing.

[0050] The first diffuser 21 can comprise fins (not shown) for correcting the air flow.

[0051] The first diffuser 21 is placed between the fan 20 and the rectifier circuit 18, the first end 21a of the diffuser abutting the fan 20 and the second end 21b being in contact with the rectifier circuit 18.

[0052] The cross-section of the first end 21a of the first diffuser is substantially the same as the cross-section of the fan and the cross-section of the second end 21b of the first diffuser is substantially the same as the cross-section of the rectifier circuit, so as to direct the air flow into the rectifier circuit.

[0053] At least some, or even most, or all of the air flow generated by the fan 20 is directed to the rectifier circuit 18. In Figures 3 to 5 In the embodiment of the figure, the entire air flow is directed to the rectifier circuit 18 by means of the diffuser 21. However, the housing 16 can be devoid of diffuser 21.

[0054] The transformer 17, the voltage rectifier circuit 18 and the fan 20 are positioned so that at least some of the air flow generated by the fan flows through the hollow central zone 23 of the rectifier so as to immerse / surround the transformer, the air flow generated by the fan 20 flowing through the central zone of the transformer and around the transformer (arrow F).

[0055] The axes of the fan 20, the rectifier circuit 18 and the transformer 17 are substantially parallel to, or even aligned with, the same axis (A) so that the air flow is directed by the rectifier circuit.

[0056] The transformer 17 and the rectifier circuit 18 have peripheral faces, such as faces 170 and 180, which lie in parallel planes or substantially coplanar planes. The term "peripheral face" is to be understood as meaning a face which does not face the hollow central region and through which the hollow central region does not pass.

[0057] The axis of the directrix of the fan 20 is substantially aligned with the axis of rotation of the fan.

[0058] The axis of the directrix of the fan 20, of the rectifier circuit and of the transformer 17 is collinear with the axis of the directrix of the hollow central region. The axis of the directrix is substantially aligned with the axis of rotation of the fan.

[0059] According to another embodiment, which can be seen in Figure 5 , the device 15 is additionally provided with a deflector 26.

[0060] The fan 20 comprises an active region for blowing the air flow and a dead region which is not used for blowing the air flow.

[0061] The deflector 26 has a size which is substantially equal to the size of the dead region and is located in the latter in an axial direction so as to direct the air flow towards the active region.

[0062] The air flow is thus forced to pass through the hollow central region of the heat sink fins 25 which are closer to the heat sink.

[0063] As shown, the deflector 26 can be cylindrical or it can match the triangular shape of the heat sink and be shaped / have a specific profile at its ends.

[0064] As shown, here the (deflector) device can be attached to the dead region of the fan. As a variant, it can also be connected to the diffuser 21 through the heat sink so as to correct the flow from the fan which is liable to form eddies.

[0065] According to another embodiment, which is shown in Figure 6 , the device 15 can comprise a second diffuser 27 which is arranged so as to surround the transformer in order to direct the part of the air flow which does not flow through the hollow central region 22 of the rectifier around the transformer.

[0066] In the embodiment of Figure 7 , the housing 30, which is otherwise identical to the above-described embodiments and variants thereof, comprises a second fan 31 which is able to extract the air produced from the fan 20.

[0067] The second fan 31 is attached to the side 30b of the housing which is opposite the side 30a of the housing 30 on which the first fan 20 is mounted.

[0068] On this side 30b, the casing comprises an opening so that the air flow generated by the first fan 20 is extracted from the casing 30 by the second fan 31.

[0069] The opening can be replaced by an air outlet hole as shown in the first embodiment of the application. Figure 3

[0070] The second fan 31 can be located inside or outside the casing 30.

[0071] Reference is made to the description of the embodiment showing the transformer 17. Figure 8 and 9 Reference is made to the description of the embodiment showing the transformer 17.

[0072] Figure 8 A second embodiment of the transformer 17 comprising a magnetic circuit forming a straight prism based on a hexagon is schematically shown.

[0073] The winding 36 of the transformer 17 is arranged on the edge of the hexagon.

[0074] In the embodiment of Figure 9 the magnetic circuit forms a straight prism based on a star, here with three branches, on each of which a winding 37 of the transformer 17 is arranged.

[0075] Advantageously, the weight of each of the transformers 17 of said embodiment is lighter than the transformers according to the prior art incorporated in a device for transforming and rectifying a three-phase voltage.

[0076] Thus, for the same electrical characteristics, the device according to the application is lighter than the devices known in the prior art for transforming and rectifying a three-phase voltage.

[0077] As shown in Figure 10 such a device can advantageously be incorporated on an aircraft 100.

[0078] The characteristics of the fan, mainly the air flow rate, the size of the hollow central zone of the transformer and of the rectification circuit are determined so that the heat dissipation of the heat generated by the transformer and the rectification diodes is sufficient to keep each component in the casing below its maximum operating temperature for a given electrical power transformed by the device.

[0079] By freeing up space inside the casing, the use of a prismatic three-phase transformer and the arrangement of the transformer, the rectification circuit, the diffuser and the fan improve the movement of the air flow.

[0080] Thus, the temperature difference between hot and cold spots is reduced, the cooling of the components inside the casing is improved and the trade-off between the space and weight constraints and the ability to cool the components arranged inside the casing is improved.​

Claims

1. Apparatus for transforming and rectifying a polyphase voltage, the apparatus comprising: A polyphase transformer (17) comprising a first hollow central zone (22); a voltage rectification circuit (18) connected to said polyphase transformer; and a fan (20), characterized in that said voltage rectification circuit comprises at least three heat dissipation units (18a, 18b, 18c, 32a, 32b, 32c, 32d, 32e, 32f) forming a straight prism of regular polygonal section comprising a second hollow central zone (23, 33), said polyphase transformer, said voltage rectification circuit and said fan being positioned so that at least some of the air flow generated by the fan flows through said second hollow central zone so as to immerse said polyphase transformer, wherein said polyphase transformer (17) comprises a magnetic circuit forming a straight prism of regular polygonal section.

2. The device for transforming and rectifying a polyphase voltage according to claim 1, wherein, Said polyphase voltage is a three-phase voltage.

3. The device for transforming and rectifying a polyphase voltage according to claim 1, wherein, Said straight prism is a triangle-based straight prism, a star-based straight prism or a hexagon-based straight prism.

4. The apparatus for transforming and rectifying a polyphase voltage according to claim 1, wherein, The fan (20), the voltage rectification circuit (18, 32) and the directrix axis of the polyphase transformer (17) are parallel to, or even aligned with, the same axis (A, B) so that the air flow is directed by the voltage rectification circuit.

5. The device for transforming and rectifying a polyphase voltage according to any one of claims 1 to 4, wherein, The peripheral face of the polyphase transformer (17) and the peripheral face of the voltage rectification circuit (18, 32) are in parallel planes, or even in coplanar planes.

6. The device for transforming and rectifying a polyphase voltage according to any one of claims 1 to 4, further comprising a first diffuser (21) placed between the fan (20) and the voltage rectification circuit (18), a first end (21a) of the first diffuser abutting the fan and a second end (21b) of the first diffuser being in contact with the voltage rectification circuit, the cross-section of the first and second ends of the first diffuser being identical to the cross-section of the fan and of the voltage rectification circuit, respectively, so as to direct the air flow into the voltage rectification circuit.

7. The device for transforming and rectifying a polyphase voltage according to any of claims 1 to 4, wherein, The fan (20) comprises an active zone for blowing the air flow and a dead zone not used for blowing the air flow, the device further comprising a directing device (26) the size of which is equal to the size of the dead zone so as to direct the air flow towards the voltage rectification circuit around the dead zone.

8. The device for transforming and rectifying a polyphase voltage according to any one of claims 1 to 4, further comprising a second diffuser (27) arranged so as to surround the polyphase transformer so as to direct the part of the air flow that does not flow through the second hollow central zone and that does not flow through the first hollow central zone of the polyphase transformer around the polyphase transformer.

9. The device for transforming and rectifying a polyphase voltage according to any of claims 1 to 4, wherein, At least one heat dissipation unit (18a, 18b, 18c, 32a, 32b, 32c, 32d, 32e, 32f) comprises a heat sink (24, 34) one face of which comprises fins (25, 35) and a rectifier diode (D, D1) arranged on the face opposite the face comprising the fins.

10. The device for transforming and rectifying a polyphase voltage according to claim 9, wherein, The heat sink (25, 35) is arranged in the second hollow central region (23, 33).

11. The apparatus for transforming and rectifying a polyphase voltage according to claim 1, wherein, The magnetic circuit comprises a plurality of magnetic elements through one or more coils, each of the magnetic elements forming a closed loop through an edge of the prism.

12. The device for transforming and rectifying a polyphase voltage according to claim 11, wherein, The number of magnetic elements is a multiple of three.

13. The device for transforming and rectifying a polyphase voltage according to any one of claims 1 to 4, further comprising a housing (16) comprising an air flow outlet aperture (16c) arranged so that the air flow generated by the fan flows through the voltage rectification circuit and the polyphase transformer before exiting through the aperture.

14. An aircraft comprising at least one device for transforming and rectifying a polyphase voltage according to one of the preceding claims.

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