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EP-4736592-A1 - APPARATUS FOR COOLING POWER ELECTRONICS COMPONENTS

EP4736592A1EP 4736592 A1EP4736592 A1EP 4736592A1EP-4736592-A1

Abstract

The object of the invention is an apparatus for cooling non-planar and planar power electronic components, such as components containing magnetic circuits. The apparatus according to the invention comprises a housing (1) filled, with a dielectric cool ant (2) with a high thermal conductivity value into which the cooled components (K1) are immersed to cool them. Further, the apparatus comprises a cooling element (3) placed inside the housing, in its upper part in contact with the coolant (2) preferably cooled outside the apparatus, with separate closed fluid circulation (5a, b) to cool the element (3) and control the temperature of the coolant (2) inside the housing (1); and a heat-conducting cooling plate ( 4 ) closing the housing (1), arranged at the top of housing (1) as its lid above the cooling element (3) so that the cooling plate (4) is in contact with the coolant (2) and/or cooling element (3) to cool the planar components arranged on the outer surface of the cooling plate.

Inventors

  • SEPPÄLÄ, Pekka

Assignees

  • MSC Control Oy

Dates

Publication Date
20260506
Application Date
20240617

Claims (15)

  1. 1. An apparatus for cooling components, such as power electronic components containing magnetic circuits, com- prising a housing (1) filled with a dielectric coolant (2) with a high thermal conductivity value, such as trans- former oil, electronic fluid or similar submersible cool- ing liquid in which the cooled components (KI) are im- mersed in order to cool them, the apparatus further com- prising, a separate cooling element (3) placed inside the housing (1) , at the upper part of it, in contact with the coolant (2) , said cooling element (3) having preferably a separate closed fluid circulation (5a, 5b) cooled out- side the apparatus to cool the element (3) and control the temperature of the coolant (2) inside the housing (1) , characterized in that the apparatus further com- prises : - a cooling plate (4) manufactured of a high thermal conductivity material, said cooling plate (4) ar- ranged at the top of the housing (1) filled with coolant as its lid in a liquid-proof manner above said separate cooling element (3) , wherein the cooling plate (4) is in contact with the coolant (2) or cool- ing element (3) and the coolant, - components (K2) cooled through a planar surface that are arranged on the surface of the cooling plate out- :er immediate t it e from it or contact with it in a heat-conducting manner so that the horizontal plane formed by the cooling element (3) is parallel to the plane formed by the base surface of the cooling plate (4) , to cool the cooling plate (4) by the influence of the cooling element (3) and the coolant (2) , and to cool components (K2) cooled through a planar sur- face being arranged on the outer surface of the cooling plate (4) .
  2. 2. The apparatus according to claim 1, characterized in that the coolant circulation (5a, 5b) of the internal cooling element (3) of the housing (1) is provided by equipment outside the housing (1) in order to inde- pendently control the temperature of the element (3) .
  3. 3. The apparatus according to claim 1 or 2, character- ized in that the housing (1) is partially or fully ther- mally insulated in its external parts.
  4. 4. The apparatus according to any of the preceding claims 1-3, characterized in that the cooling plate (4) is preferably a planar plate made of a material with a high thermal conductivity value, such as metal.
  5. The apparatus according to any of the preceding claims 1-4, characterized in that the cooling element (3) is a tubular body made of high thermal conductivity ma- terial, preferably of a serpentine shape in order to in- crease the cooling area.
  6. 6. The apparatus according to any of the preceding claims 1-5, characterized in that the cooled components (KI) , such as magnetic circuits, are arranged detachably in the interior of the housing.
  7. 7. The apparatus according to any of the preceding claims 1-6, characterized in that the components (K2) cooled through a planar surface and arranged on the outer surface of the cooling plate (4) are transistors, thy- ristors or similar used in power electronics and/or cir- cuit boards or similar substrates to which the components (K2) to be cooled are attached in order to cool them.
  8. 8. The apparatus according to any ot the preceding claims 1-7, characterized in that the housing (1) is made of metal, plastic, composite, and/or similar material t hold the coolant (2) .
  9. 9. The apparatus according to claim 1-8, characterized in that the lower part and/or bottom of the housing (1) is preferably fitted with a precipitate bowl in order to collect any precipitate potentially formed from compo- nents (KI) and/or coolant (2) .
  10. 10. The apparatus according to any of the preceding claims 1-9, characterized in that the apparatus comprises an external pump or similar apparatus for the creation of forced convection in the coolant (2) inside the housing (1) •
  11. 11. The apparatus according to any of the preceding claims 1-10, characterized in that lamellas or similar structures, such as projections and indentations to en- hance neat transfer by controlling and/or controlling convective flows inside the housing (1) are arranged in connection with the internal space of the housing (1) and/or the cooling plate (4) .
  12. 12. The apparatus according to any of the preceding claims 1-11, characterized in that mounting structures are arranged in the internal space of the housing (1) for the components (KI) , the cooling plate (4) and cooling element (3) for their fixed and/or removable attachment in the housing (1) in order to replace them independently.
  13. 13. The apparatus according to any of the preceding claims 1-12, characterized in that a safety valve or equivalent arrangement is arranged in the housing (1) and/or cooling plate (4) to equalize the pressure in the housing (1) to prevent the pressure increase to an ex- cessive level due to temperature rise in the event of overheating and/or failure of the apparatus.
  14. 14. The apparatus according to any of the preceding claims 1-13, characterized in that appropriate valves, such as check valves or equivalent, are arranged in the housing (1) and/or the cooling plate (4) to add and/or reduce the coolant (2) .
  15. 15. The apparatus according to any of the preceding claims 1-14, characterized in that the cooling element (3) is integrated into the surface of the cooling plate (4) in fixed manner by a highly thermally conductive pro- cess such as soldering, welding and/or gluing, wherein the cooling element (3) and cooling plate (4) are in fixed contact with each other in order to conduct heat between the cooling element (3) and the cooling plate (4) ; or with suitable clips in the immediate vicinity of the cooling plate (4) at such a distance (s) that the coolant (2) can flow between the element (3) and the cooling plate

Description

Apparatus tor cooling power electronics components The object of the invention is an apparatus as presented in the preamble to the independent claim directed thereto for the cooling of specifically power electronic compo- A significant part of the weight, volume and cost of power converters and other components containing magnetic cir- cuits is due to transferring of heat losses created inside the converter components away from the apparatus, i.e. cooling the components. For this reason, in high-power power converters, it is cost-effective to maximize the proportion of liquid cooling and minimize the number of >arts required for this. Power converters contain components (e.g. power semicon- ductors) where the generated loss heat is directed to the planar highly heat-conducting surface of the component. However, the power converter has also components (e.g. magnetic circuits) where the heat loss is conducted in several directions and on surfaces of different shapes. For example, inductors generate heat three-dimensionally through non-planar surfaces, which makes it challenging to cool them using only its planar surfaces. At present, in power electronics, devices containing mag- netic components (magnetic circuits) that generate heat through losses are typically cooled convectively by air- flow, either passively using various cooling fin solu- tions to increase the area of the cooling surface, or actively combining fans with the above. Devices with mag- netic components can be additionally cooled by immersing them in a non-conductive (dielectric) , but heat- conducting coolant, or using combinations of the above. These solutions typically require cooling fins on the outside surface of the device, which limits the use of the outside surface for other purposes, such as attaching accessories . Publication EP 2 790 311 Al presents a converter solution wherein capacitive elements are immersed in a heat-con- ducting liquid. The solution is passively cooled with ribs outside the housing, "which can be further enhanced by using external fans. The publication focuses essen- tially on the structure of the cooled capacitive compo- nent in order to cool it efficiently. Publication WO/2020/200523 presents a cooling solution for magnetic components of power electronics used to en- sure power supply to data centers, wherein components are embedded in a coolant. Vaporization and convective move- ment occur in the liquid heated by the components, cre- ating internal circulation of the liquid. The circulation is directed through a cooling element/heat sink, wherein its mass causes vapor condensation and fluid circulation. Power semiconductor components, such as thyristors or IGBT transistors, are attached on the cooling elements. However, according to the publication, the liquid is not actively cooled. Further, publication US 2013/0122331 presents a solution suitable for cooling hybrid car battery cells, wherein the battery cells are placed in a housing and immersed in a heat-conducting liquid with which the housing is filled so that the cells are completely subsurface, but the housing is not completely filled. A cooling element is also placed inside the housing, which can be, for example, hydronic and with a purpose to cool the liquid in the housing. The purpose of the cooling element is to condense the boiling coolant for recirculation, and it has not been completely immersed in the coolant. In turn, the publication SE 2030079 Al presents a liquid- tilled housing cooled by a cooling plate intended for a battery module. The cooling plate is placed on the bottom or sides of the housing. Further, publication EP 4 093 170 Al presents a cooling plate immersed in liquid that cools the liquid in a tank. Components that require cooling are also embedded in the tank. In the solution, a forced flow with the help of pumps is used to provide a coolant flow. The publication CN 107135632 describes an apparatus for cooling electronic components, in particular a printed circuit board and the components arranged on it. In the apparatus according to the invention, the circuit board and its components are arranged inside a housing, which is further filled with heat-conducting dielectric liquid to cool the components. The publication describes a cool- ing plate placed under the printed circuit board with a separate internal coolant circulation to cool the board. The housing is closed above with a plate with feedthroughs placed on it, means to fill the case with liquid, and a display for indicating the temperature. Further, accord- ing to an embodiment of the invention, the housing can be cooled by cooling elements arranged on its side walls, which may be equipped with fans and/or cooling fins. All the above-mentioned prior art publications present attempts to cool heat-generating components with the help of liquid. However, the presented inventions are either inefficient or complex in their construction, causing unnecessary costs when app