U.S. patent application number 17/153455 was filed with the patent office on 2022-07-21 for busbar assembly for current sensing.
The applicant listed for this patent is GM Global Technology Operations LLC. Invention is credited to Muhammad H. Alvi, Chandra S. Namuduri, Rashmi Prasad.
Application Number | 20220232723 17/153455 |
Document ID | / |
Family ID | |
Filed Date | 2022-07-21 |
United States Patent
Application |
20220232723 |
Kind Code |
A1 |
Alvi; Muhammad H. ; et
al. |
July 21, 2022 |
BUSBAR ASSEMBLY FOR CURRENT SENSING
Abstract
A busbar assembly includes a base having a width and a length.
The base has a first surface and a second surface and has a first
side and a second side. A distance between the first side and the
second side comprises the width, and the base defines a slot
centered between approximately 75% and approximately 79% of the
width.
Inventors: |
Alvi; Muhammad H.; (Troy,
MI) ; Prasad; Rashmi; (Troy, MI) ; Namuduri;
Chandra S.; (Troy, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GM Global Technology Operations LLC |
Detroit |
MI |
US |
|
|
Appl. No.: |
17/153455 |
Filed: |
January 20, 2021 |
International
Class: |
H05K 7/14 20060101
H05K007/14 |
Claims
1. A busbar assembly, comprising: a base having a width and a
length, the base having a first surface and a second surface, the
base having a first side and a second side, wherein a distance
between the first side and the second side comprises the width, and
wherein the base defines a slot centered between approximately 75%
and approximately 79% of the width.
2. The busbar assembly of claim 1, wherein the base defines the
slot centered between approximately 76% and approximately 78% of
the width.
3. The busbar assembly of claim 1, wherein the base defines the
slot centered at 77% of the width.
4. The busbar assembly of claim 1, wherein the slot comprises an
aperture extending through the base.
5. The busbar assembly of claim 1, wherein the base further defines
a channel between the first side and the second side.
6. The busbar assembly of claim 5, further comprising a printed
circuit board disposed over the first surface, wherein a flanged
portion of the printed circuit board extends through the channel,
the flanged portion including at least one current sensing device
configured to measure current parameters of current flow through
the base.
7. The busbar assembly of claim 6, wherein the at least one current
sensing device comprises a point field detector.
8. The busbar assembly of claim 6, wherein the at least one current
sensing device is galvanically isolated from the base.
9. The busbar assembly of claim 1, wherein the width is at least
four times a thickness of the base.
10. A busbar assembly, comprising: a base having a width and a
length, the base having a first surface and a second surface, the
base having a first side and a second side, wherein a distance
between the first side and the second side comprises the width,
wherein the base defines a slot centered between approximately 75%
and approximately 79% of the width; and a printed circuit board
disposed over the first surface, wherein a flanged portion of the
printed circuit board extends through a channel, the flanged
portion including at least one current sensing device configured to
measure current parameters of current flow through the base.
11. The busbar assembly of claim 10, wherein the base defines the
slot centered between approximately 76% and approximately 78% of
the width.
12. The busbar assembly of claim 10, wherein the base defines the
slot centered at 77% of the width.
13. The busbar assembly of claim 10, wherein the slot comprises an
aperture extending through the base.
14. The busbar assembly of claim 10, wherein the base further
defines the channel between the first side and the second side.
15. The busbar assembly of claim 10, wherein the at least one
current sensing device comprises a point field detector.
16. The busbar assembly of claim 10, wherein the at least one
current sensing device is galvanically isolated from the base.
17. The busbar assembly of claim 10, wherein the width is at least
four times a thickness of the base.
18. A busbar assembly, comprising: a base having a width and a
length, the base having a first surface and a second surface, the
base having a first side and a second side, wherein a distance
between the first side and the second side comprises the width,
wherein the base defines a slot centered between approximately 75%
and approximately 79% of the width and the width is at least four
times a thickness of the base; and a printed circuit board disposed
over the first surface, wherein a flanged portion of the printed
circuit board extends through a channel, the flanged portion
including at least one current sensing device configured to measure
current parameters of current flow through the base.
19. The busbar assembly of claim 18, wherein the base defines the
slot centered between approximately 76% and approximately 78% of
the width.
20. The busbar assembly of claim 18, wherein the base defines the
slot centered at 77% of the width.
Description
INTRODUCTION
[0001] The present disclosure relates to busbar assemblies, and
more particularly to busbar assemblies for current sensing.
[0002] Vehicles, such as battery-electric vehicles (BEVs), plug-in
hybrid-electric vehicles (PHEVs), mild hybrid-electric vehicles
(MHEVs), or full hybrid-electric vehicles (FHEVs), may contain one
or more energy storage devices, such as a high voltage (HV)
battery, that functions as a propulsion source for the vehicle. The
HV battery may include components and systems to assist in managing
vehicle performance and operations. The HV battery may also include
one or more arrays of battery cells interconnected electrically
between battery cell terminals and interconnector busbars
SUMMARY
[0003] According to several aspects of the present disclosure, a
busbar assembly includes a base having a width and a length. The
base has a first surface and a second surface and has a first side
and a second side. A distance between the first side and the second
side comprises the width, and the base defines a slot centered
between approximately 75% and approximately 79% of the width.
[0004] In other features, the base defines the slot centered
between approximately 76% and approximately 78% of the width.
[0005] In other features, the base defines the slot centered at 77%
of the width.
[0006] In other features, the slot comprises an aperture extending
through the base.
[0007] In other features, the base further defines a channel
between the first side and the second side.
[0008] In other features, the busbar assembly includes a printed
circuit board disposed over the first surface, wherein a flanged
portion of the printed circuit board extends through the channel,
where the flanged portion includes at least one current sensing
device configured to measure current parameters of current flow
through the base.
[0009] In other features, the at least one current sensing device
comprises a point field detector.
[0010] In other features, the at least one current sensing device
is galvanically isolated from the base.
[0011] In other features, the width is at least four times the
thickness.
[0012] According to several aspects of the present disclosure,
busbar assembly includes a base having a width and a length, the
base having a first surface and a second surface and having a first
side and a second side. A distance between the first side and the
second side comprises the width of the base, and the base defines a
slot centered between approximately 75% and approximately 79% of
the width. The busbar assembly includes a printed circuit board
disposed over the first surface. A flanged portion of the printed
circuit board extends through a channel, and the flanged portion
includes at least one current sensing device configured to measure
current parameters of current flow through the base.
[0013] In other features, the base defines the slot centered
between approximately 76% and approximately 78% of the width.
[0014] In other features, the base defines the slot centered at 77%
of the width.
[0015] In other features, the slot comprises an aperture extending
through the base.
[0016] In other features, the base further defines the channel
between the first side and the second side.
[0017] In other features, the at least one current sensing device
comprises a point field detector.
[0018] In other features, the at least one current sensing device
is galvanically isolated from the base.
[0019] In other features, the width is at least four times a
thickness of the base.
[0020] According to several aspects of the present disclosure,
busbar assembly includes a base having a width and a length, the
base having a first surface and a second surface and having a first
side and a second side. A distance between the first side and the
second side comprises the width of the base. The base defines a
slot centered between approximately 75% and approximately 79% of
the width and the width is at least four times a thickness of the
base. The busbar assembly includes a printed circuit board disposed
over the first surface. A flanged portion of the printed circuit
board extends through a channel, and the flanged portion includes
at least one current sensing device configured to measure current
parameters of current flow through the base.
[0021] In other features, the base defines the slot centered
between approximately 76% and approximately 78% of the width.
[0022] In other features, the base defines the slot centered at 77%
of the width.
[0023] Further areas of applicability will become apparent from the
description provided herein. It should be understood that the
description and specific examples are intended for purposes of
illustration only and are not intended to limit the scope of the
present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The drawings described herein are for illustration purposes
only and are not intended to limit the scope of the present
disclosure in any way.
[0025] FIG. 1 is a schematic diagram of an example battery electric
vehicle according to an example implementation;
[0026] FIG. 2A is an isometric view of a busbar assembly according
to an example implementation;
[0027] FIG. 2B is an isometric view of a busbar assembly according
to an example implementation;
[0028] FIG. 3 is an isometric view of a busbar assembly including a
printed circuit board disposed over a surface of the busbar
assembly according to an example implementation; and
[0029] FIG. 4 is a side view of a busbar assembly including a
printed circuit board disposed over a surface of the busbar
assembly according to an example implementation.
DETAILED DESCRIPTION
[0030] The following description is merely exemplary in nature and
is not intended to limit the present disclosure, application, or
uses.
[0031] In some vehicle environments, busbars are used within
vehicle battery assemblies, e.g., battery packs, to provide for
local current power distribution. In some implementations, busbars
may incorporate current sensing capabilities for control and
protection of electronic components. However, current busbars may
fail to provide suitable current sensing capabilities due to
external disturbances, lack of galvanic isolation, and frequency
dependent skin and proximity effects. As discussed herein, a busbar
assembly can include a single slot that is asymmetrically centered
to allow one or more current sensing devices to access and measure
differential fields. Based on the configuration of the single slot,
the one or more current sensing devices are also galvanically
isolated from a base of the busbar.
[0032] The positioning of the single slot within the busbar
assembly can allow for sensing of magnetic fields that have minimal
frequency dependency. In other words, the position of the slot can
provide a spatial position within the busbar assembly that is
appropriate for sensing a magnetic field and/or current ranging
from current having direct current (DC) characteristics to current
having a frequency characteristic up to ten (10) megahertz
(MHz).
[0033] FIG. 1 depicts a schematic of an example of a plug-in
hybrid-electric vehicle (PHEV). A vehicle 12 may include one or
more electric machines 14 mechanically connected to a hybrid
transmission 16. The electric machines 14 may be capable of
operating as a motor and/or a generator. In addition, the hybrid
transmission 16 can be mechanically connected to an engine 18. The
hybrid transmission 16 can also be mechanically connected to a
drive shaft 20 that is mechanically connected to the wheels 22. The
electric machines 14 can provide propulsion and deceleration
capability when the engine 18 is turned on or off. The electric
machines 14 may also function as generators and can provide fuel
economy benefits by recovering energy that would normally be lost
as heat in the friction braking system.
[0034] A traction battery 24, e.g., a battery pack, stores and
provides energy that can be used by the electric machines 14 or
other vehicle 12 components. The traction battery 24 typically
provides a high voltage DC output from one or more battery cell
arrays, sometimes referred to as battery cell stacks, within the
traction battery 24. The high voltage DC output may also be
converted to a low voltage DC output for applications such as
vehicle stop/start. The battery cell arrays may include one or more
battery cells. The traction battery 24 may be electrically
connected to one or more power electronics modules 26 through one
or more contactors. The one or more contactors isolate the traction
battery 24 from other components when opened and connect the
traction battery 24 to other components when closed. The power
electronics module 26 is also electrically connected to the
electric machines 14 and provides the ability to bi-directionally
transfer electrical energy between the traction battery 24 and the
electric machines 14. For example, a typical traction battery 24
may provide a DC voltage while the electric machines 14 may require
a three-phase AC voltage to function. The power electronics module
26 may convert the DC voltage to a three-phase AC voltage as
required by the electric machines 14. In a regenerative mode, the
power electronics module 26 may convert the three-phase AC voltage
from the electric machines 14 acting as generators to the DC
voltage required by the traction battery 24. The description herein
may be applicable to a pure electric vehicle or other hybrid
vehicles. For a pure electric vehicle, the hybrid transmission 16
may be a gear box connected to an electric machine 14 and the
engine 18 may not be present.
[0035] In addition to providing energy for propulsion, the traction
battery 24 may provide energy for other vehicle electrical systems.
A typical vehicle electrical system may include a DC/DC converter
module 28 that converts the high voltage DC output of the traction
battery 24 to a low voltage DC supply that is compatible with other
vehicle loads. Other high-voltage loads, such as compressors and
electric heaters, may be connected directly to the high-voltage
without the use of a DC/DC converter module 28. In a typical
vehicle, the low-voltage systems are electrically connected to an
auxiliary battery 30, e.g., 12V battery.
[0036] A battery electrical control module (BECM) 33 may be in
communication with the traction battery 24. The BECM 33 may
function as a controller for the traction battery 24 and may also
include an electronic monitoring system that manages temperature
and charge state of each of the battery cells. The traction battery
24 may have a temperature sensor 31, such as a thermistor or other
temperature gauge. The temperature sensor 31 may be in
communication with the BECM 33 to provide temperature data
regarding the traction battery 24. The temperature sensor 31 may
also be located on or near the battery cells within the traction
battery 24. It is also contemplated that more than one temperature
sensor 31 may be used to monitor temperature of the battery
cells.
[0037] The vehicle 12 may be, for example, an electric vehicle such
as a PHEV, a FHEV, a MHEV, or a BEV in which the traction battery
24 may be recharged by an external power source 36. The external
power source 36 may be a connection to an electrical outlet. The
external power source 36 may be electrically connected to electric
vehicle supply equipment (EVSE) 38. The EVSE 38 may provide
circuitry and controls to regulate and manage the transfer of
electrical energy between the power source 36 and the vehicle 12.
The external power source 36 may provide DC or AC electric power to
the EVSE 38. The EVSE 38 may have a charge connector 40 for
plugging into a charge port 34 of the vehicle 12. The charge port
34 may be any type of port configured to transfer power from the
EVSE 38 to the vehicle 12. The charge port 34 may be electrically
connected to a charger or on-board power conversion module 32. The
power conversion module 32 may condition the power supplied from
the EVSE 38 to provide the proper voltage and current levels to the
traction battery 24. The power conversion module 32 may interface
with the EVSE 38 to coordinate the delivery of power to the vehicle
12. The EVSE connector 40 may have pins that mate with
corresponding recesses of the charge port 34.
[0038] The various components discussed may have one or more
associated controllers to control and monitor the operation of the
components. The controllers may communicate via a serial bus (e.g.,
Controller Area Network (CAN)) or via discrete conductors.
[0039] The battery cells, such as a prismatic cell, may include
electrochemical cells that convert stored chemical energy to
electrical energy. Prismatic cells may include a housing, a
positive electrode (cathode) and a negative electrode (anode). An
electrolyte may allow ions to move between the anode and cathode
during discharge, and then return during recharge. Terminals may
allow current to flow out of the cell for use by the vehicle. When
positioned in an array with multiple battery cells, the terminals
of each battery cell may be aligned with opposing terminals
(positive and negative) adjacent to one another and a busbar may
assist in facilitating a series connection between the multiple
battery cells. The battery cells may also be arranged in parallel
such that similar terminals (positive and positive or negative and
negative) are adjacent to one another. For example, two battery
cells may be arranged with positive terminals adjacent to one
another, and the next two cells may be arranged with negative
terminals adjacent to one another. In this example, the busbar may
contact terminals of all four cells. The traction battery 24 may be
heated and/or cooled using a liquid thermal management system, an
air thermal management system, or other method as known in the
art.
[0040] FIGS. 2A and 2B illustrate an example busbar assembly 100
according to an example implementation of the present disclosure.
The busbar assembly 100 includes a base 102 and a single
asymmetrically positioned slot 104 defined within the base 102,
i.e., an aperture defined within the base 102. In various
implementations, the busbar assembly 100 can span between a first
battery cell and a second battery cell within the traction battery
24. The busbar assembly 100 may also be located between a battery,
e.g., the traction battery 24, and other power electronics within
the vehicle 12 and/or between a power electronics module and one or
more electric machines 14. The busbar assembly 100 may be
manufactured using a suitable metallic material to allow current
flow. For example, the busbar assembly 100 may be comprised of
copper, brass, and/or aluminum. The metallic material may include a
first and a second generally planar surface. Referring to FIG. 2B,
the busbar assembly 100 can define a channel 106 in some
implementations as described in greater detail below.
[0041] Referring to FIG. 3, the base 102 of the busbar assembly 100
has a thickness (T), a width (W), and a length (L). The slot 104
can be asymmetrically centered within the base 102 between a range
of approximately 75% and approximately 79% of the width as measured
from a distal side 108 of the base 102, which is referred to as a
distance D, i.e., a center point of the slot is positioned between
approximately 75% and approximately 79% of the width as measured
from the distal side 108. In an example implementation, the slot
104 can be centered within the base 102 such that the slot 104 is
centered between approximately 76% and approximately 78% of the
width as measured from the distal side 108. In another example
implementation, the slot 104 can be centered within the base 102 at
77% of the width as measured from the distal side 108. In this
context, the term "approximately" is known to those skilled in the
art. Alternatively, the term "approximately" may be read to mean
plus or minus 5%.
[0042] In some implementations, the width of the slot 104 may range
between about two (2) millimeters (mm) and about four (4)
millimeters (mm). In an example implementation, the width of the
slot 104 may be three (3) millimeters (mm). The width of the base
102 may range between about fifteen (15) millimeters (mm) and about
fifty (50) millimeters (mm). The thickness of the busbar assembly
100 can be a function of the width of the busbar assembly 100. In
an example implementation, the width of the busbar assembly 100 is
at least four (4) times the thickness of the busbar assembly 100 as
defined in Equation 1:
W>4*T Eqn. 1
[0043] Referring to FIG. 4, a printed circuit board 150 may be
positioned over a generally planar surface 152 of the busbar
assembly 100. A size of the printed circuit board 150 may vary
based on the electronic modules and/or specialized sensing devices
built in. The printed circuit board 150 can be attached, i.e.,
mounted, to the busbar assembly 100 via any suitable attachment
techniques. For example, the printed circuit board 150 may be
mounted to the busbar assembly 100 via one or more fasteners, e.g.,
screws, bolts, etc. A frame (not shown) to retain the printed
circuit board 150 may also be attached to the busbar assembly 100.
The printed circuit board 150 can include one or more electronic
modules, e.g., components. As shown, the printed circuit board 150
can include one or more current sensing devices 154. The printed
circuit board 150 can define a flanged portion 156 that extends
outwardly away from the printed circuit board 150 and has a width
that is less than a width of the printed circuit board 150.
[0044] As shown in FIGS. 3 and 4, the one or more current sensing
devices 154 can be attached to the flanged portion 156. The flanged
portion 156 may be integral with the printed circuit board 150 in
some implementations. In other implementations, the flanged portion
156 is separate and can be attached to the printed circuit board
150 via one or more connectors. The width of the flanged portion
156 is less than a width of the slot 104 such that the flanged
portion 156 and the one or more current sensing devices 154 can
extend through the slot 104 when the printed circuit board 150 is
attached to the busbar assembly 100.
[0045] The one or more current sensing devices 154 can comprise
point field detectors (PFDs). The point field detectors can be used
for high-bandwidth galvanically-isolated current sensing. The
current sensing device 154 can measure current parameters, e.g.,
differential field parameters, corresponding to current flow
through the busbar assembly 100. As shown in FIG. 4, the current
sensing device 154 and the flanged portion 156 extend into the
channel 106. Depending on a configuration of the busbar assembly
100, a thickness of the channel 106 can range between one (1)
millimeter (mm) and two and a half (2.5) millimeters (mm). In these
implementations, the current sensing device(s) 154 may extend
beyond a generally planar surface 158 of the busbar assembly 100.
The busbar assembly 100 can include the channel 106 when the
thickness of the busbar assembly 100 is greater than a
predetermined thickness.
[0046] While FIGS. 3 and 4 illustrate a single current sensing
device 154, it is understood that two or more current sensing
devices 154 can be attached to the printed circuit board 150. For
example, a first current sensing device may be attached to the
flanged portion 156 such that the first current sensing device is
proximal to the surface 152, and a second current sensing device
may be attached to the flanged portion 156 such that the second
current sensing device extends beyond a surface 160 of the channel
106 and/or extends beyond the surface 158 when the base 102 does
not defined a channel 106. It is understood that the busbar
assembly 100 may be manufactured such that a cross-section of the
busbar supports a range of current flow, e.g., ranging from about
one hundred (100) Amperes (A) to about two thousand (2,000)
Amperes.
[0047] Various components of the printed circuit board 150 may be
connected to one or more controllers of the vehicle 12 such that
the one or more controllers can receive the measurements from the
one or more current sensing devices 154. The current sensing
devices 154 may be used to sense DC current provided by the
traction battery 24 and/or phase current for an inverter that is
provided to the electric machines 14, e.g., motor and/or generator.
While FIGS. 4 and 5 illustrate the non-flanged portion of the
printed circuit board 150 as being generally perpendicular to the
surface 152, in some example implementations, the non-flanged
portion of the printed circuit board 150 may be generally parallel
to the surface 152.
[0048] The description of the present disclosure is merely
exemplary in nature and variations that do not depart from the gist
of the present disclosure are intended to be within the scope of
the present disclosure. Such variations are not to be regarded as a
departure from the spirit and scope of the present disclosure.
* * * * *