U.S. patent application number 16/533176 was filed with the patent office on 2021-02-11 for vascular cooled capacitor assembly and method.
This patent application is currently assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC. The applicant listed for this patent is GM GLOBAL TECHNOLOGY OPERATIONS LLC. Invention is credited to Anthony M. Coppola, Alireza Fatemi, Thomas W. Nehl.
Application Number | 20210043389 16/533176 |
Document ID | / |
Family ID | 1000004261662 |
Filed Date | 2021-02-11 |
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United States Patent
Application |
20210043389 |
Kind Code |
A1 |
Coppola; Anthony M. ; et
al. |
February 11, 2021 |
VASCULAR COOLED CAPACITOR ASSEMBLY AND METHOD
Abstract
A vascular cooled capacitor assembly includes a plurality of
capacitors having respective first and second leads, first and
second busbars disposed in electrical contact with the first and
second leads, an encapsulant enveloping the capacitors and a
respective major portion of each of the first and second busbars,
and a network of channels enveloped within the encapsulant and
formed by deflagration of a sacrificial material. The network has
at least one network inlet and at least one network outlet, each of
which is configured for sealable engagement with a cooling fluid
system. A branch of each channel is positioned inside a central
axial passage of a capacitor, around an outer periphery of a
capacitor, and/or between two capacitors. A housing may enclose the
capacitors, the channels and major portions of the first and second
busbars.
Inventors: |
Coppola; Anthony M.;
(Rochester Hills, MI) ; Fatemi; Alireza; (Canton,
MI) ; Nehl; Thomas W.; (Shelby Township, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GM GLOBAL TECHNOLOGY OPERATIONS LLC |
Detroit |
MI |
US |
|
|
Assignee: |
GM GLOBAL TECHNOLOGY OPERATIONS
LLC
Detroit
MI
|
Family ID: |
1000004261662 |
Appl. No.: |
16/533176 |
Filed: |
August 6, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01G 9/012 20130101;
H01G 9/0003 20130101; H01G 9/26 20130101; H01G 9/08 20130101 |
International
Class: |
H01G 9/00 20060101
H01G009/00; H01G 9/26 20060101 H01G009/26; H01G 9/012 20060101
H01G009/012; H01G 9/08 20060101 H01G009/08 |
Claims
1. A capacitor assembly configured for use with a cooling fluid
system, comprising: a plurality of capacitors, each capacitor
having respective first and second leads and a respective central
axial passage extending along at least a portion of a respective
axial length thereof; first and second busbars disposed in
electrical contact with the first and second leads, respectively;
an encapsulant enveloping the plurality of capacitors and a
respective major portion of each of the first and second busbars;
and a network of channels enveloped within the encapsulant and
formed by deflagration of a sacrificial material, each channel
having a respective inlet end and a respective outlet end, the
network having at least one network inlet configured to direct
fluid flow into the inlet ends and at least one network outlet
configured to direct fluid flow away from the outlet ends, wherein
at least one branch of each channel is positioned as being at least
one of inside the central axial passage of at least one of the
capacitors, around an outer periphery of at least one of the
capacitors, and between at least two of the capacitors, and wherein
each of the at least one network inlet and the at least one network
outlet is configured for sealable engagement with the cooling fluid
system.
2. A capacitor assembly according to claim 1, wherein the network
of channels is formed by: forming a network of sacrificial
components corresponding to the network of channels, the network of
sacrificial components being positioned as at least one of within
the encapsulant and on a surface of at least one of the first and
second busbars; igniting the sacrificial components to cause
deflagration of the sacrificial components, thereby forming the
network of channels.
3. A capacitor assembly according to claim 1, wherein the network
includes at least one manifold, each of the at least one manifold
having at least one respective first inlet/outlet port and at least
one respective second inlet/outlet port in fluid communication with
the at least one first inlet/outlet port, wherein each of the at
least one first inlet/outlet port is configured for sealable
engagement with the cooling fluid system, and wherein each of the
at least one second inlet/outlet port is in fluid communication
with one of the at least one inlet end and at least one outlet
end.
4. A capacitor assembly according to claim 1, wherein each channel
has a respective channel wall wherein a respective first portion of
at least one channel wall is formed by the encapsulant.
5. A capacitor assembly according to claim 4, wherein a second
portion of the at least one channel wall is formed by a respective
surface of one of the first and second busbars.
6. A capacitor assembly according to claim 1, further comprising a
housing enclosing the plurality of capacitors, the respective major
portions of the first and second busbars, and the encapsulant.
7. A capacitor assembly according to claim 1, further comprising a
respective tube disposed within the respective central axial
passage of each capacitor.
8. A capacitor assembly according to claim 7, wherein each
respective tube is in fluid communication with the network of
channels.
9. A capacitor assembly according to claim 1, wherein the at least
one branch enters a respective central axial passage at a first
respective end thereof and exits the respective central axial
passage at one of the first respective end and a second respective
end thereof.
10. A capacitor assembly according to claim 1, wherein the cooling
fluid system is an electronic module having a surface configured
for mounting the capacitor assembly thereon, at least two cooling
fluid interfaces on the surface, and a cooling fluid supply and
return system in fluid communication with the at least two cooling
fluid interfaces, wherein each of the at least one network inlet
and the at least one network outlet is configured for sealable
engagement with a respective one of the at least two cooling fluid
interfaces.
11. A vascular cooled capacitor assembly, comprising: a plurality
of capacitors, each capacitor having respective first and second
leads and a respective central axial passage extending along at
least a portion of a respective axial length thereof; first and
second busbars disposed in electrical contact with the first and
second leads, respectively; a housing enclosing the plurality of
capacitors and a respective major portion of each of the first and
second busbars; an encapsulant filling at least a majority of free
space within the housing; and a network of channels formed by
deflagration of a sacrificial material, each channel having a
respective inlet end and a respective outlet end, the network
having at least one network inlet configured to direct fluid flow
into the inlet ends and at least one network outlet configured to
direct fluid flow away from the outlet ends, wherein at least one
branch of each channel is positioned as being at least one of
inside the central axial passage of at least one of the capacitors,
around an outer periphery of at least one of the capacitors, and
between at least two of the capacitors, and wherein each of the at
least one network inlet and the at least one network outlet is
configured for sealable engagement with a cooling fluid system;
wherein the network of channels is formed by: forming a network of
sacrificial components corresponding to the network of channels,
the network of sacrificial components being positioned as at least
one of within the encapsulant and on a surface of at least one of
the first and second busbars; and igniting the sacrificial
components to cause deflagration of the sacrificial components,
thereby forming the network of channels.
12. A vascular cooled capacitor assembly according to claim 11,
wherein the network includes at least one manifold, each of the at
least one manifold having at least one respective first
inlet/outlet port and at least one respective second inlet/outlet
port in fluid communication with the at least one first
inlet/outlet port, wherein each of the at least one first
inlet/outlet port is configured for sealable engagement with the
cooling fluid system, and wherein each of the at least one second
inlet/outlet port is in fluid communication with one of at least
one inlet end and at least one outlet end.
13. A vascular cooled capacitor assembly according to claim 11,
wherein each channel has a respective channel wall wherein a
respective first portion of at least one channel wall is formed by
the encapsulant.
14. A vascular cooled capacitor assembly according to claim 13,
wherein a second portion of the at least one channel wall is formed
by a respective surface of one of the first and second busbars.
15. A vascular cooled capacitor assembly according to claim 11,
wherein the cooling fluid system is an electronic module having a
surface configured for mounting the capacitor assembly thereon, at
least two cooling fluid interfaces on the surface, and a cooling
fluid supply and return system in fluid communication with the at
least two cooling fluid interfaces, wherein each of the at least
one network inlet and the at least one network outlet is configured
for sealable engagement with a respective one of the at least two
cooling fluid interfaces.
16. A vascular cooled capacitor system, comprising: a plurality of
capacitors, each capacitor having respective first and second leads
and a respective central axial passage extending along at least a
portion of a respective axial length thereof; first and second
busbars disposed in electrical contact with the first and second
leads, respectively; a housing enclosing the plurality of
capacitors and a respective major portion of each of the first and
second busbars; an encapsulant filling at least a majority of free
space within the housing; a network of channels formed by
deflagration of a sacrificial material, each channel having a
respective inlet end and a respective outlet end, the network
having at least one network inlet configured to direct fluid flow
into the inlet ends and at least one network outlet configured to
direct fluid flow away from the outlet ends, wherein at least one
branch of each channel is positioned as being at least one of
inside the central axial passage of at least one of the capacitors,
around an outer periphery of at least one of the capacitors, and
between at least two of the capacitors; and a cooling fluid system
having a surface onto which the housing is mounted, at least two
cooling fluid interfaces on the surface, and a cooling fluid supply
and return system in fluid communication with the two cooling fluid
interfaces, wherein each of the at least one network inlet and the
at least one network outlet is sealably engaged with a respective
one of the at least two cooling fluid interfaces.
17. A vascular cooled capacitor system according to claim 16,
wherein the network of channels is formed by: forming a network of
sacrificial components corresponding to the network of channels,
the network of sacrificial components being positioned as at least
one of within the encapsulant and on a surface of at least one of
the first and second busbars; and igniting the sacrificial
components to cause deflagration of the sacrificial components,
thereby forming the network of channels.
18. A vascular cooled capacitor system according to claim 16,
wherein the network includes first and second manifolds each having
at least one respective first inlet/outlet port and at least one
respective second inlet/outlet port, each of the at least one first
inlet/outlet port is sealably engaged with a respective one of the
at least two cooling fluid interfaces, and each of the at least one
second inlet/outlet port is in fluid communication with one of at
least one inlet end and at least one outlet end.
19. A vascular cooled capacitor system according to claim 16,
wherein each channel has a respective channel wall wherein a
respective first portion of at least one channel wall is formed by
the encapsulant.
20. A vascular cooled capacitor system according to claim 19,
wherein a second portion of the at least one channel wall is formed
by a respective surface of one of the first and second busbars.
Description
INTRODUCTION
[0001] This disclosure relates to vascular cooled capacitor
assemblies and methods for making such assemblies.
[0002] Capacitors are temperature-sensitive and may experience
challenges when used in environments having temperatures higher
than the specified operating range of the capacitors. For example,
capacitors may be used in traction inverter modules and other
electronic modules where significant heat may be generated.
[0003] Solid electrolytic capacitors may be considered for such
applications due to their relatively low cost and high capacitance
per unit volume. However, their higher equivalent series resistance
may limit their effective use in such applications as automotive
traction power inverters. Providing larger electrical busbars may
provide additional heat removal capacity, but adds size, mass and
cost.
SUMMARY
[0004] According to one embodiment, a capacitor assembly configured
for use with a cooling fluid system includes: a plurality of
capacitors, each capacitor having respective first and second leads
and a respective central axial passage extending along at least a
portion of a respective axial length thereof; first and second
busbars disposed in electrical contact with the first and second
leads, respectively; an encapsulant enveloping the plurality of
capacitors and a respective major portion of each of the first and
second busbars; and a network of channels enveloped within the
encapsulant and formed by deflagration of a sacrificial material.
Each channel has a respective inlet end and a respective outlet
end. The network has at least one network inlet configured to
direct fluid flow into the inlet ends and at least one network
outlet configured to direct fluid flow away from the outlet ends.
At least one branch of each channel is positioned as being at least
one of inside the central axial passage of at least one of the
capacitors, around an outer periphery of at least one of the
capacitors, and between at least two of the capacitors. Each of the
at least one network inlet and the at least one network outlet is
configured for sealable engagement with the cooling fluid system.
The capacitor assembly may further include a housing enclosing the
plurality of capacitors, the respective major portions of the first
and second busbars, and the encapsulant.
[0005] The network of channels may be formed by forming a network
of sacrificial components corresponding to the network of channels
(the network of sacrificial components being positioned as at least
one of within the encapsulant and on a surface of at least one of
the first and second busbars), and igniting the sacrificial
components to cause deflagration of the sacrificial components,
thereby forming the network of channels.
[0006] The network may include at least one manifold, each of the
at least one manifold having at least one respective first
inlet/outlet port and at least one respective second inlet/outlet
port in fluid communication with the at least one first
inlet/outlet port, wherein each of the at least one first
inlet/outlet port is configured for sealable engagement with the
cooling fluid system, and wherein each of the at least one second
inlet/outlet port is in fluid communication with one of the at
least one inlet end and at least one outlet end.
[0007] Each channel may have a respective channel wall wherein a
respective first portion of at least one channel wall is formed by
the encapsulant. A second portion of the at least one channel wall
may be formed by a respective surface of one of the first and
second busbars.
[0008] The capacitor assembly may further include a respective tube
disposed within the respective central axial passage of each
capacitor. Each respective tube may be in fluid communication with
the network of channels. The at least one branch may enter a
respective central axial passage at a first respective end thereof
and exit the respective central axial passage at one of the first
respective end and a second respective end thereof.
[0009] The cooling fluid system may be an electronic module having
a surface configured for mounting the capacitor assembly thereon,
at least two cooling fluid interfaces on the surface, and a cooling
fluid supply and return system in fluid communication with the at
least two cooling fluid interfaces, wherein each of the at least
one network inlet and the at least one network outlet is configured
for sealable engagement with a respective one of the at least two
cooling fluid interfaces.
[0010] According to one embodiment, a vascular cooled capacitor
system includes: a plurality of capacitors, each capacitor having
respective first and second leads and a respective central axial
passage extending along at least a portion of a respective axial
length thereof first and second busbars disposed in electrical
contact with the first and second leads, respectively; a housing
enclosing the plurality of capacitors and a respective major
portion of each of the first and second busbars; an encapsulant
filling at least a majority of free space within the housing; a
network of channels formed by deflagration of a sacrificial
material (each channel having a respective inlet end and a
respective outlet end, the network having at least one network
inlet configured to direct fluid flow into the inlet ends and at
least one network outlet configured to direct fluid flow away from
the outlet ends, wherein at least one branch of each channel is
positioned as being at least one of inside the central axial
passage of at least one of the capacitors, around an outer
periphery of at least one of the capacitors, and between at least
two of the capacitors); and a cooling fluid system having a surface
onto which the housing is mounted, at least two cooling fluid
interfaces on the surface, and a cooling fluid supply and return
system in fluid communication with the two cooling fluid
interfaces, wherein each of the at least one network inlet and the
at least one network outlet is sealably engaged with a respective
one of the at least two cooling fluid interfaces.
[0011] The network may include first and second manifolds each
having at least one respective first inlet/outlet port and at least
one respective second inlet/outlet port, each of the at least one
first inlet/outlet port being sealably engaged with a respective
one of the at least two cooling fluid interfaces, and each of the
at least one second inlet/outlet port being in fluid communication
with one of at least one inlet end and at least one outlet end.
Each channel may have a respective channel wall wherein a
respective first portion of at least one channel wall is formed by
the encapsulant. A second portion of the at least one channel wall
may be formed by a respective surface of one of the first and
second busbars. The vascular cooled capacitor system may further
include a respective tube disposed within the respective central
axial passage of each capacitor, wherein the at least one branch
enters a respective tube at a first respective end thereof and
exits the respective tube at one of the first respective end and a
second respective end thereof.
[0012] The above features and advantages, and other features and
advantages, of the present teachings are readily apparent from the
following detailed description of some of the best modes and other
embodiments for carrying out the present teachings, as defined in
the appended claims, when taken in connection with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is an exploded perspective view of a vascular cooled
capacitor assembly.
[0014] FIG. 2 is a perspective view of busbars for a vascular
cooled capacitor assembly.
[0015] FIGS. 3-4 are schematic semi-sectional side views of a
vascular cooled capacitor assembly, but with the busbars not
shown.
[0016] FIGS. 5-10 are schematic flow diagrams of various
network/channel configurations for a vascular cooled capacitor
assembly.
[0017] FIGS. 11-14 are schematic sectional side views of various
configurations of a vascular cooled capacitor assembly, but with
the capacitors not shown.
[0018] FIG. 15 is a schematic sectional side view of a
capacitor.
[0019] FIG. 16 is a schematic sectional side view of a vascular
cooled capacitor assembly.
[0020] FIG. 17 is a schematic isometric view of a substrate molded
to a sacrificial component.
[0021] FIG. 18 is a schematic sectional view of the sacrificial
component, taken along section 2-2 of FIG. 17.
[0022] FIG. 19 is a schematic isometric view of the sacrificial
component being ignited while still partly disposed inside the
substrate.
[0023] FIG. 20 is a schematic isometric view depicting the
deflagration of the sacrificial component in the substrate.
[0024] FIG. 21 is a schematic isometric view depicting a channel of
the substrate being cleaned after the deflagration of the
sacrificial component.
[0025] FIG. 22 is a schematic sectional view of a substrate molded
to a sacrificial component, wherein the sacrificial component
includes intersecting filaments.
[0026] FIG. 23 is a schematic sectional view of the substrate shown
in FIG. 22, while the sacrificial component is being ignited.
[0027] FIG. 24 is a schematic sectional view of the substrate shown
in FIG. 23, depicting the breached channel after the sacrificial
component has been ignited.
[0028] FIG. 25 is a schematic isometric view of a 3D printer
creating a sacrificial component.
[0029] FIG. 26 is a schematic isometric view of a sacrificial
component.
[0030] FIG. 27 is a schematic front view of the sacrificial
component of FIG. 26 inside a mold.
[0031] FIG. 28 is a schematic front view of the sacrificial
component of FIG. 26 inside the mold, wherein resin or metal has
been poured in the mold.
[0032] FIG. 29 is a schematic front view of the sacrificial
component of FIG. 26 inside the mold after the resin has been cured
or the metal has been cooled.
[0033] FIG. 30 is a schematic front view of the substrate after
removing the sacrificial component.
[0034] FIG. 31 is a schematic front view of a sacrificial component
formed using 3D printing.
[0035] FIG. 32 is a schematic front view of the sacrificial
component of FIG. 31 being dip coated.
[0036] FIG. 33 is a schematic front view of the sacrificial
component of FIG. 31 after being dip coated.
[0037] FIG. 34 is a schematic front view of the sacrificial
component of FIG. 31 while the coating is being cured.
[0038] FIG. 35 is a schematic front view of the sacrificial
component (after being dip coated and cured) and placed in a
substrate.
DETAILED DESCRIPTION
[0039] Referring now to the drawings, wherein like numerals
indicate like parts in the several views, a vascular cooled
capacitor assembly/system 20 is shown and described herein. The
description "vascular" is used herein to refer to a system of
internal passages for the flow of fluid (i.e., cooling fluid),
similar to the vascular or circulatory system of passages within
the human body for the flow of blood.
[0040] FIG. 1 shows an exploded perspective view of an exemplary
capacitor assembly 20 according to the present disclosure. The
capacitor assembly 20 includes a plurality of capacitors 30, a
first busbar 40, and a second busbar 50, all of which may be placed
into a housing 70 whose interior free space 72 may be filled with
an encapsulant 80. (As discussed below, alternative configurations
of the capacitor assembly 20 may exclude the housing 70.) The two
busbars 40, 50 represent separate "positive" and "negative"
electrical busses for the capacitors 30. When the busbars 40, 50
are disposed within the interior 72 of the housing 70, their
respective electrodes may protrude out through the housing so that
they may be electrically connected to other devices. These
electrodes may include end tabs 42 and side tabs 44 for the first
busbar 40, and end tabs 52 and side tabs 54 for the second busbar
50.
[0041] FIG. 15 shows a schematic sectional side view of a
representative capacitor 30. Each capacitor 30 has a first lead 35
and a second lead 36 (which are the electrical connections for the
capacitor 30), as well as a central axial passage 37 extending
along at least a portion 38 of a respective axial length 34 as
measured along the longitudinal axis 31 of the capacitor 30. This
length 34 may be measured from a first or "bottom" end 33 of the
capacitor 30 (where the leads 35, 36 may be located) to a second or
"top" end 32. The passage 37 may be formed when the various
conductive and dielectric layers are rolled to form the capacitor
30. The passage 37 may extend through the entire length 34 of the
capacitor 30; or, if the capacitor 30 is sealed or welded on one
end 32 thereof, the central axial passage 37 may extend for a
shorter length 38. When the capacitors 30 are situated in the
housing 70, the first and second busbars 40, 50 are disposed so as
to be in electrical contact with the first and second leads 35, 36,
respectively.
[0042] With the capacitors 30 and busbars 40, 50 installed in the
housing 70, an encapsulant 80 may be poured in so as to fill much
(or all) of the interior free space 72 within the housing 70. The
encapsulant 80 may be any suitable electrically insulative
material, and it may envelope (i.e., enclose, contain, surround,
etc.) the plurality of capacitors 30 and a respective major portion
of each of the first and second busbars 40, 50, and may be heated
or allowed to set in order to cure the electrically insulative
encapsulant material 80. Alternatively, the housing 70 may be
omitted, with the capacitors 30 and busbars 40, 50 being placed in
a suitable mold and the encapsulant 80 being poured into the mold
and cured.
[0043] In either configuration (i.e., with or without a housing
70), a network 108n of channels 108, formed by deflagration of a
sacrificial material, is disposed and enveloped within the
encapsulant 80. This network 108n of channels 108 may serve as a
"vascular system" within the capacitor assembly 20, through which a
cooling fluid may be circulated for cooling the plurality of
capacitors 30. The network 108n of channels 108 may be formed by
forming a network 110 of sacrificial components 102 made of
combustible sacrificial material embedded in the encapsulant
material 80 corresponding to a desired network 108n of channels
108, and then (as explained in more detail below) igniting the
sacrificial components 102 to cause deflagration of the sacrificial
components 102, thereby producing the desired network 108n of
channels 108. The network 110 of sacrificial components 102 may be
positioned (i.e., located and arrayed, spatially disposed, etc.)
within the encapsulant material 80, on one or more surface(s) of
one or both busbars 40, 50, or both within the encapsulant 80 and
on one more busbar surface(s).
[0044] FIG. 2 shows an exemplary arrangement of busbars 40, 50 on
which a network 110 of sacrificial components 102 is disposed. The
network 110 is applied to a top surface 41 of a first busbar 40,
and includes multiple filaments 102, 102a, 102b, 112. For example,
filament 102a is disposed on an outer side wall of the first busbar
40 so as to avoid the series of large oval holes 46, and filament
102b lies on the same wall adjacent a series of small circular
holes 48. The network 110 has two ends 103 as shown, which may
serve as fluid flow inlets or outlets once the busbars 40, 50 have
been encapsulated in encapsulant material 80 and the components 102
have been ignited and deflagrated to form the channels 108, as
further described below.
[0045] FIGS. 3-4 show schematic semi-sectional side views of two
different configurations of a vascular cooled capacitor assembly
20, but with the busbars 40, 50 removed for purposes of
illustration, and FIGS. 5-10 show schematic flow diagrams of
various network 108n and channel 108 configurations for a vascular
cooled capacitor assembly 20. Each of the channels 108 has a
respective inlet end 82 and a respective outlet end 84. The network
108n has at least one network inlet 86 configured to direct fluid
flow into the inlet ends 82 of the channels 108, and at least one
network outlet 88 configured to direct fluid flow away from the
outlet ends 84. At least one branch of each channel 108 is
spatially disposed or positioned in at least one of the following
three dispositions or locations within the capacitor assembly 20:
(i) inside the central axial passage 37 of at least one of the
capacitors 30, (ii) around an outer periphery of at least one of
the capacitors 30, and (iii) between at least two of the capacitors
30. For example, in FIGS. 3-4, branches 108i and 108t run inside
the central axial passage(s) 37 of one or more capacitors 30,
branch 108a runs around the outer periphery(-ies) of one or more
capacitors 30, and branch 108b runs between at least two capacitors
30.
[0046] Each of the at least one network inlet 86 and the at least
one network outlet 88 is configured for sealable engagement with a
cooling fluid system 90, which may be external to the capacitor
assembly 20. (Alternatively, the capacitor assembly/system 20 may
include the cooling fluid system 90.) The cooling fluid system 90
may be an electronic module (e.g., a power module, a control
module, etc.) having a surface 92 configured for mounting the
capacitor assembly 20 thereon. The cooling fluid system 90 may have
two or more cooling fluid interfaces 94 on the surface 92, and a
cooling fluid supply and return system 96 in fluid communication
with the cooling fluid interfaces 94. Each of the cooling fluid
interfaces 94 may be connected to the cooling fluid supply and
return system 96 via fluid channels 98 that are internal to the
module 90. Each of the at least one network inlet 86 and each of
the at least one network outlet 88 is configured for sealable
engagement with a respective one of the two cooling fluid
interfaces 94, such as by the use of suitable fluid fittings or
connectors. When the capacitor assembly 20 is sealably connected
with the electronic module/cooling fluid system 90, the cooling
fluid provided by the cooling fluid supply and return system 96 may
circulate through the network 108n of channels 108 (i.e., the
vascular system of the capacitor assembly 20), thereby providing
cooling to the plurality of capacitors 30.
[0047] FIGS. 5-10 show several exemplary network/channel flow
diagrams for a vascular cooled capacitor assembly 20. FIGS. 5-7
show examples without the use of a manifold, while FIGS. 8-10
illustrate examples with one or two manifolds 60, 65. Each example
includes a network 108n of two or more channels 108, which may be
interconnected (as in FIGS. 6 and 9) or not. Each individual
channel 108 has an inlet end 82 and an outlet end 84, and each
collection or network 108n of channels 108 has one or more network
inlets 86 and one or more network outlets 88. For example, the
network 108n shown in FIG. 5 has three non-interconnected channels
108, so that network 108n would have three inlet ends 82, three
outlet ends 84, three network inlets 86 and three network outlets
88, wherein each inlet end 82 is also a network inlet 86 and each
outlet end 84 is also a network outlet 88. In contrast, the network
108n shown in FIG. 6 has three interconnected channels 108 which
converge at two convergence nodes 85; this network 108n would have
one inlet end 82, one outlet end 84, one network inlet 86 and one
network outlet 88, wherein each inlet end 82 is also a network
inlet 86 and each outlet end 84 is also a network outlet 88. (Note
that the three channels 108 shown in FIG. 9 are interconnected by
two crossover or connecting branches 113.) Each of the examples
shown in FIGS. 5-10 also includes at least one supply 95 of cooling
fluid (which may come from a cooling fluid system/module 90) and at
least one return 97 for the cooling fluid. A cooling fluid
interface 94 (such as an adapter or connector) is provided for each
supply 95 and return 97, and each network inlet 86 and network
outlet 88 is configured to sealably engage with a respective
cooling fluid interface 94.
[0048] FIGS. 7-10 illustrate networks 108n having at least one
manifold 60, 65 which may be used for directing cooling fluid flow
between the cooling fluid system 90 and the network 108n of
channels 108. Each manifold 60, 65 has at least one respective
first inlet/outlet (I/O) port 62, 66 and at least one respective
second I/O port 64, 68 in fluid communication with at least one of
the at least one first I/O port 62, 66. Each first I/O port 62, 66
is configured for sealable engagement with the cooling fluid system
90 (such as with a supply 95 or return 97, via a suitable connector
or coupling 94), and each second I/O port 64, 68 is in fluid
communication with one or more channel inlet ends 82 or one or more
channel outlet ends 84. In other words, each manifold 60, 65 is
configured to couple the network 108n with one or more elements
external to the network 108n. More specifically, the first I/O
ports 62, 66 may be configured for engagement with elements
external to the network 108n (e.g., the supply 95 and return 97),
while the second I/O ports 64, 68 may be configured for engagement
with elements internal to the network 108n (e.g., the channels
108). When two or more manifolds 60, 65 are used as part of a
capacitor assembly 20--such as in FIGS. 7-9 where a first manifold
60 is provided for the inlet side and a second manifold 65 for the
outlet side--each first I/O port 62, 66 may serve as either a
network inlet 86 or a network outlet 88. For example, each first
I/O port 62 for the first manifold 60 may serve as a network inlet
86, and each first I/O port 66 for the second manifold 65 may serve
as a network outlet 88. When one manifold 60 is used--such as in
FIG. 10--the first I/O port 62 may serve as a network inlet 86
(connecting to a cooling fluid supply 95), the second I/O port 64
may connect with the channels 108, and a third I/O port 67 may
serve as a network outlet 88 (connecting to a cooling fluid return
97).
[0049] FIGS. 11-14 show schematic sectional side views of various
configurations of a vascular cooled capacitor assembly 20 without a
housing 70, but with the capacitors 30 not shown for the purposes
of illustration. Each channel 108 has one or more channel walls
105. For example, a channel 108 having a circular cross-section has
one circumferential channel wall 105, while a channel 108 having a
rectangular cross-section has four channel walls 105. A first
portion 107 of at least one channel wall 105 is formed by the
encapsulant 80, while a second portion 109 of the at least one
channel wall 105 may be formed by a respective surface of one of
the first and second busbars 40, 50. For example, in FIG. 11, two
rectangular channels 108 are shown, with each having four channel
walls 105, and with the channels 108 disposed with one of its
respective walls 109 in contact with the busbar 40. Each of these
two channels 108 has three walls 107 formed by the encapsulant
material 80, and one wall 109 formed by a surface 41, 43 of the
first busbar 40. In this case, the first portion 107 and the three
encapsulant-formed walls 107 are synonymous with each other, while
the second portion 109 and the one busbar surface-formed wall 109
are also synonymous with each other. In contrast, in FIG. 12 the
channels 108 appear to be "floating" in the encapsulant 80 with no
channel walls 105 in contact with the busbar 40; in fact, there is
a gap 74 or spacing between each surface 41, 43 of the busbar 40
and its adjacent channel 108, and this gap 74 is filled with
encapsulant 80, such that the encapsulant 80 forms all four of the
channel walls 105, 107. For any given channel 108, the entire
length and circumference/perimeter thereof may be either fully
encapsulated (like in FIG. 12) or partially/mostly encapsulated but
in contact with a busbar surface 41, 43 (like in FIG. 11); or, the
degree of encapsulation may vary along the length and/or
circumference/perimeter of the channel 108.
[0050] FIGS. 13-14 show two capacitor assemblies 20 where a hole
may be formed through a busbar 40 so that a connecting channel 108c
may be formed through the hole. For example, a bolt (not shown)
with a central axial hole through its length may be used to fasten
the busbar 40 to a module/cooling fluid system 90, such that
cooling fluid may run through the hole formed in the bolt. Gaskets
or o-rings 91 may be used to seal the encapsulated capacitor
assembly 20 when it is fastened to the cooling fluid system/module
90. FIG. 14 illustrates how two or more busbars 40, 50 may be
stacked and fastened together with a hole and connecting channel
108c running through both busbars 40, 50.
[0051] FIG. 16 shows a schematic sectional side view of a vascular
cooled capacitor assembly 20. As with the configurations shown in
FIGS. 11-14, a housing 70 is not shown; instead, the capacitor
assembly 20 is shown encapsulated or enveloped by the encapsulant
80, forming an outer surface or envelope 81 around the capacitors
30, busbars 40, 50 and channels 108. As illustrated by FIG. 16, a
capacitor assembly 20 may include: a plurality of capacitors 30,
with each capacitor 30 having respective first and second leads 35,
36 and a respective central axial passage 37 extending along at
least a portion 38 of a respective axial length 34 thereof; first
and second busbars 40, 50 disposed in electrical contact with the
first and second leads 35, 36, respectively; an encapsulant 80
enveloping the plurality of capacitors 30 and a respective major
portion of each of the first and second busbars 40, 50; and a
network 108n of channels 108 enveloped within the encapsulant 80
and formed by deflagration of a sacrificial material, each channel
108 having a respective inlet end 82 and a respective outlet end
84, the network 108n having at least one network inlet 86
configured to direct fluid flow into the inlet ends 82 and at least
one network outlet 88 configured to direct fluid flow away from the
outlet ends 84, wherein at least one branch of each channel 108 is
positioned (i) inside the central axial passage 37 of at least one
of the capacitors 30 (i.e., branch 108i or 108t), (ii) around an
outer periphery of at least one of the capacitors 30 (i.e., branch
108a), and/or (iii) between at least two of the capacitors 30
(i.e., branch 108b), and wherein each of the at least one network
inlet 86 and the at least one network outlet 88 is configured for
sealable engagement with a cooling fluid system 90. The capacitor
assembly 20 may further include a housing 70 enclosing the
plurality of capacitors 30, the respective major portions of the
first and second busbars 40, 50, and the encapsulant 80.
[0052] As shown in FIGS. 3, 4 and 15, the capacitor assembly 20 may
further include a respective tube 56 disposed within the respective
central axial passage 37 of each capacitor 30. This tube 56 may be
made of a polymer or an insulator-coated metal, and may be added to
each capacitor 30 as part of the fabrication process, such as by
using the tube 56 as a mandrel onto which the conductive and
dielectric layers may be rolled to form the capacitor 30. The tube
56 may have a first or bottom end 57 aligned with the first or
bottom end 33 of the capacitor, and a second or top end 58 aligned
with the second or top end 32 of the capacitor 30. Or, the tube 56
may be formed of sacrificial material similar to the network 110 of
filaments 112, and the tube filament 112 may be deflagrated to form
the tube 56. Each respective tube 56 may be in fluid communication
with the network 108n of channels 108, such that cooling fluid may
pass into/through each capacitor 30. If the tube 56 extends through
the full axial length 34 of the capacitor 30, then a channel 108
may pass through the tube 56 and serve as a "through" branch 108t
(see FIG. 3), but if the tube 56 only extends a portion 38 of the
axial length 34, then a channel 108 may enter and exit one side 57
the tube 56 and may serve as an "in-and-out" branch 108i (see FIG.
4).
[0053] The vascular system or network 108n of channels 108
according to the present disclosure is effective for providing
cooling to capacitors 30 and/or busbars 40, 50, such as may be used
in capacitor assemblies 20 in hybrid automotive vehicles, power
systems, and the like. By taking advantage of the cooling provided,
designers may utilize different (and more optimal) sizes and
arrangements of capacitors 30 and/or busbars 40, 50 for a given
package size.
[0054] The process of forming the network 108n of channels 108 will
now be discussed in more detail. With reference to FIG. 17, the
present disclosure describes a method of forming channels 108
within or on a substrate 100 using deflagration of a sacrificial
material. The substrate 100 may be an encapsulant 80 as described
above, and/or the substrate may be a busbar 40, 50, with the
channels 108 formed within the encapsulant 80 and/or on the busbar
surface(s) 41, 43. In this method, a sacrificial component 102 may
be molded directly into/onto the substrate 100 as shown in FIG. 17.
For example, the sacrificial component 102 may be molded directly
into/onto the substrate 100 such that the sacrificial component 102
is disposed inside of or on a surface of the substrate 100. For
instance, after molding, a majority of the sacrificial component
102 may be entirely disposed inside the substrate 100 to facilitate
the formation of thru-holes. However, at least part of the
sacrificial component 102 should be disposed outside of the
substrate 100 to allow it to be ignited as discussed below.
[0055] With reference to FIG. 18, the sacrificial component 102 may
include a combustible core 104 and an optional protective shell 106
surrounding the combustible core 104. The combustible core 104
allows for rapid deflagration but not detonation. The heat
generated during deflagration is dissipated rapidly enough to
prevent damage to the substrate 100. After deflagration, the
combustible core 104 may generate easy-to-remove byproducts, such
as fine powdered and large gaseous components. It is contemplated
that the combustible core 104 may be self-oxidizing to burn in a
small diameter along long channels. The combustible core 104 may
also be resistant to molding pressures. Further, the combustible
core 104 may be shelf stable and stable during manufacturing (i.e.,
the flash point is greater than the manufacturing or processing
temperature). The term "flash point" means the lowest temperature
at which vapors of a combustible material will ignite, when given
an ignition source. The sacrificial component 102 may be molded
directly to the substrate 100 at a processing temperature that is
less than the flash point of the combustible material to avoid
deflagration during the manufacturing process. The term "processing
temperature" means a temperature required to perform a
manufacturing operation, such as molding or casting. For example,
the processing temperature may be the melting temperature of the
material forming the substrate 100 (i.e., the melting temperature
of the polymeric resin forming the substrate 100). The combustible
core 104 is wholly or partly made of a combustible material. To
achieve the desired properties mentioned above, the combustible
material may be black powder (i.e., a mixture of sulfur, charcoal,
and potassium nitrate). To achieve the desired properties mentioned
above, the combustible material may alternatively or additionally
be pentaerythritol tetranitrate, combustible metals, combustible
oxides, thermites, nitrocellulose, pyrocellulose, flash powders,
and/or smokeless powder. Non-combustible materials could be added
to the combustible core 104 to tune speed and heat generation. To
tune speed and heat generation, suitable non-combustible materials
for the combustible core 104 include, but are not limited to, glass
beads, glass bubbles, and/or polymer particles.
[0056] The optional protective shell 106 may be made of a
protective material, which may be non-soluble material in
combustible resin (e.g., epoxy, polyurethane, polyester, among
others) in order to be shelf stable and stable during
manufacturing. Also, this protective material may be impermeable to
resin and moisture. The protective material may have sufficient
structural stability to be integrated into a fiber textiling and
preforming process. The protective material may have sufficient
strength and flexibility to survive the fiber preform process. To
achieve the desirable properties mentioned above, the protective
material may include, for example, braided fibrous material, such
as glass fiber, aramid fiber, carbon fiber, and/or natural fiber,
infused with an infusion material such as a polymer or wax, oil, a
combination thereof or similar material. To achieve the desirable
properties mentioned above, the infused polymer may be, for
example, polyimide, polytetrafluoroethylene (PTFE), high-density
polyethylene (HDPE), polyphenylene sulfide (PPS), polyphthalamide
(PPA), polyamides (PA), polypropylene, nitrocellulose, phenolic,
polyester, epoxy, polylactic acid, bismaleimides, silicone,
acrylonitrile butadiene styrene, polyethylene, polycarbonate,
elastomers, polyurethane, polyvinylidene chloride (PVDC), polyvinyl
chloride (PVC), polystyrene (PS) a combination thereof, or any
other suitable plastic. Suitable elastomers include, but are not
limited to, natural polyisoprene, synthetic polyisoprene,
polybutadiene (BR), chloroprene rubber (CR), butyl rubber,
styrene-butadiene rubber, nitrile rubber, ethylene propylene
rubber, epichlorohydrin rubber (ECO), polyacrylic rubber,
fluorosilicone rubber, perfluoroelastomers, polyether block amides,
chlorosulfonated polyethylene, ethylene-vinyl acetate, shellac
resin, nitrocellulose lacquer, epoxy resin, alkyd, polyurethane,
etc.
[0057] With reference to FIG. 19, after molding the sacrificial
component 102 directly to the substrate 100, the sacrificial
component 102 is ignited. To do so, a flame may be placed in direct
contact with the sacrificial component 102 to cause an ignition I.
A lighter or any device capable of producing a flame can be used to
ignite the sacrificial component 102.
[0058] With reference to FIG. 20, the ignition I causes
deflagration of the sacrificial component 102. Deflagration
converts the solid sacrificial material into gaseous and fine
powder byproducts. As a consequence, a channel 108 is formed in/on
the substrate 100. The sacrificial component 102 may be cylindrical
in order to form the channel 108 with a cylindrical shape. The
sacrificial component 102 may alternatively have other shapes, such
as triangular, elliptical, rectangular, etc. Further, before
ignition I, the sacrificial component 102 may extend through the
entire length L (FIG. 17) of the substrate 100 or substrate
perimeter such that, after deflagration, the channel 108 extends
through the entire length L (FIG. 17) of the substrate 100.
[0059] With reference to FIG. 21, after deflagration, the channel
108 may optionally be cleaned to remove byproducts of the
deflagration of the sacrificial component 102. To do so, a liquid
W, such as water, may be introduced into the channel 108 of the
substrate 100 to remove byproducts of the deflagration of the
sacrificial component 102. A hose H may be used to introduce the
liquid W into the channel 108. A gas, such as air, may
alternatively or additionally may be shot into the channel 108 to
remove byproducts of the deflagration of the sacrificial component
102. Or, the channel 108 may not need any cleaning of
byproducts.
[0060] With reference to FIGS. 22-24, the method described above
can be used to provide the substrate 100 with a branched
channel-network 108n (FIG. 24). Accordingly, the method shown in
FIGS. 22-24 is substantially similar to the method described above
with respect to FIGS. 17-21, except for the differences described
below. In this method, the sacrificial component 102 is also molded
directly into/onto the substrate 100, but the sacrificial component
102 is configured as a network 110 including filaments 112 which
may intersect each other or otherwise branch off from one another.
After molding the sacrificial component 102 to the substrate 100,
the sacrificial component 102 is ignited as described above to
cause deflagration of the sacrificial component 102 as shown in
FIG. 23, thereby producing the substrate 100 with the branched
channel-network 108n as shown in FIG. 24.
[0061] With reference to FIG. 25, any of the methods described
herein may further include forming the sacrificial component 102
using an additive manufacturing process to allow the formation of
sacrificial component 102 with complex shapes. In the present
disclosure, the term "additive manufacturing process" means a
process in which a 3D object is built by adding layer-upon-layer of
material. 3D printing process is a kind of additive manufacturing
process. In the present disclosure, the term "3D printing process"
means a process in which a 3D Computer Aided Design (CAD) model is
read by a computer, and the computer commands the 3D printer 114 to
add successive layers of material to create a 3D object that
corresponds to the 3D CAD model. The sacrificial component 102 may
use a 3D printing process (by employing the 3D printer 114) to
create sacrificial components 102 with complex shapes. Accordingly,
substrates 100 with channels 108 having complex shapes can be
created. In this method, the sacrificial component 102 can be
wholly or partly made, for example, of commercial 3D printing sugar
and/or the rocket propellant known as Rocket Candy. One or both
busbars 40, 50 and/or partially encapsulated portions of a
capacitor assembly 20 may be placed into the 3D printing machine
114, and the sacrificial components 102 3D printed thereon.
[0062] With reference to FIGS. 26-30, any of the methods described
herein may entail first forming the sacrificial component 102 as
described above. In order to achieve a complex shape, the
sacrificial component 102 may be created using the 3D printing
process described above. Then, the sacrificial component 102,
busbars 40, 50, and/or partially encapsulated portion of the
capacitor assembly 20 may be placed inside a mold 116 as shown in
FIG. 24. Next, a resin or liquid metallic material 120 is poured in
the mold 116 as shown in FIG. 28. Then, the resin is cured
(through, for example, heating for a predetermined amount of time
at a predetermined curing temperature) or the metallic material is
cooled (for a predetermined amount of time) to form the substrate
100. The metallic material 120 is cooled until it solidifies to
form the substrate 100 as shown in FIG. 29. Next, the sacrificial
component 102 and the substrate 100 are removed from the mold 116,
and then the sacrificial component 102 is removed (through
deflagration as described above) as shown in FIG. 30. By employing
this process, substrates 100 with a branched channel-network 108n
having a complex shape can be created with low-pressure cast
materials, such as low-temperature metals and polymers.
[0063] With reference to FIGS. 31-35, the sacrificial component 102
may be formed using a 3D printing process as described below (see
FIG. 31). Then, the sacrificial component 102 may be coated with a
coat 126 (see FIG. 32). For example, the sacrificial component 102
may be dipped in a container 124 holding the coat 126. In other
words, the sacrificial component 102 may be dip coated. The coat
126 may be wholly or partly made of a coating material. The modulus
of resilience of the coating material (i.e., the first modulus of
resilience) may be greater than the modulus of resilience of the
combustible material of the sacrificial component 102 (i.e., the
second modulus of resilience) in order to enhance the durability of
the sacrificial material 102 during the manufacturing process. For
example, the coating material may be a toughened epoxy. Because of
its resilience, the coat 126 allows the sacrificial component 102
to be used in higher pressure manufacturing, such as for continuous
fiber composites. After dip coating the sacrificial component 102,
the sacrificial component 102 is removed from the container 124 as
shown in FIG. 34. Then, the coat 126 is cured (through, for
example, heating at a curing temperature for a predetermined curing
time) as shown in FIG. 35. Next, the sacrificial component 102
(with the coat 126) may be embedded in/onto the substrate 100
(through molding as described above).
[0064] The above description is intended to be illustrative, and
not restrictive. While various specific embodiments have been
presented, those skilled in the art will recognize that the
disclosure can be practiced with various modifications within the
spirit and scope of the claims. While the dimensions and types of
materials described herein are intended to be illustrative, they
are by no means limiting and are exemplary embodiments. Moreover,
in the following claims, use of the terms "first", "second", "top",
"bottom", etc. are used merely as labels, and are not intended to
impose numerical or positional requirements on their objects. As
used herein, an element or step recited in the singular and
preceded by the word "a" or "an" should be understood as not
excluding plural of such elements or steps, unless such exclusion
is explicitly stated. Additionally, the phrase "at least one of A
and B" should be understood to mean "only A, only B, or both A and
B." Furthermore, references to a particular embodiment or example
are not intended to be interpreted as excluding the existence of
additional embodiments or examples that also incorporate the
recited features. Moreover, unless explicitly stated to the
contrary, embodiments "comprising" or "having" an element or a
plurality of elements having a particular property may include
additional such elements not having that property. And when broadly
descriptive adverbs such as "substantially" and "generally" are
used herein to modify an adjective, these adverbs mean "for the
most part", "to a significant extent" and/or "to a large degree",
and do not necessarily mean "perfectly", "completely", "strictly"
or "entirely".
[0065] This written description uses examples, including the best
mode, to enable those skilled in the art to make and use devices,
systems and compositions of matter, and to perform methods,
according to this disclosure. It is the following claims, including
equivalents, which define the scope of the present disclosure.
* * * * *