Apparatus and method for selecting ground capacitor
11415953 · 2022-08-16
Assignee
Inventors
Cpc classification
H01M2010/4271
ELECTRICITY
B60R16/033
PERFORMING OPERATIONS; TRANSPORTING
H01M10/425
ELECTRICITY
B60L50/60
PERFORMING OPERATIONS; TRANSPORTING
B60L58/10
PERFORMING OPERATIONS; TRANSPORTING
G01R27/20
PHYSICS
Y02E60/10
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
H01M2220/20
ELECTRICITY
B60K6/28
PERFORMING OPERATIONS; TRANSPORTING
H05K1/0215
ELECTRICITY
Y02T10/62
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
International classification
H01M10/42
ELECTRICITY
G01R27/20
PHYSICS
B60L58/10
PERFORMING OPERATIONS; TRANSPORTING
Abstract
An apparatus and method for selecting a ground capacitor that is connected between a ground of a circuit board included in a battery pack and a vehicle chassis. The apparatus includes a checking module configured to check a ground location on the circuit board; a selecting module configured to select a reference location on the circuit board, based on the ground location checked by the checking module; a calculating module configured to calculate a distance from the reference location selected by the selecting module to a nearest ground location as a reference distance; a computing module configured to compute a reference frequency by using the reference distance calculated by the calculating module; and a choosing module configured to choose a recommended capacitor, based on the reference frequency computed by the computing module.
Claims
1. An apparatus for selecting a ground capacitor that is connected between a ground of a circuit board included in a battery pack and a vehicle chassis, the apparatus comprising: a checking module configured to check one or more ground locations on the circuit board; a selecting module configured to select a reference location on the circuit board, based on the one or more ground locations checked by the checking module; a calculating module configured to calculate a distance from the reference location selected by the selecting module to a nearest ground location as a reference distance; a computing module configured to compute a reference frequency by using the reference distance calculated by the calculating module; and a choosing module configured to choose a recommended capacitor, based on the reference frequency computed by the computing module.
2. The apparatus for selecting a ground capacitor according to claim 1, wherein the circuit board is coupled to the vehicle chassis by a bolt, and wherein the ground capacitor has one end connected to the bolt and the other end connected to the ground of the circuit board.
3. The apparatus for selecting a ground capacitor according to claim 1, wherein the checking module checks locations of a connector terminal and the ground capacitor provided at the circuit board, as the one or more ground locations.
4. The apparatus for selecting a ground capacitor according to claim 1, wherein the selecting module forms a circle around each of the one or more ground locations with the same radius and selects at least a part of a region positioned out of the formed circles and existing on the circuit board as the reference location.
5. The apparatus for selecting a ground capacitor according to claim 4, wherein the selecting module calculates a distance from a center point of two ground locations to each ground location, selects a minimum distance that is shortest among the calculated distances, identifies a ground location pair where the selected minimum distance is longest, and sets a distance from a center point of the identified ground location pair to the identified ground location pair as the radius.
6. The apparatus for selecting a ground capacitor according to claim 1, wherein the selecting module selects the reference location as a region, and wherein the calculating module calculates a distance from a center point of the region to a nearest ground location as the reference distance.
7. The apparatus for selecting a ground capacitor according to claim 1, wherein the computing module computes a wavelength at the circuit board and a wavelength in air in order by using the reference distance and computes the reference frequency according to the computed wavelength in air.
8. The apparatus for selecting a ground capacitor according to claim 1, wherein the choosing module chooses a capacitor having a resonance frequency equal to or lower than the reference frequency as the recommended capacitor.
9. The apparatus for selecting a ground capacitor according to claim 8, wherein the choosing module chooses a capacitor having a lowest parasitic resistance among capacitors having a resonance frequency equal to or lower than the reference frequency as the recommended capacitor.
10. The apparatus for selecting a ground capacitor according to claim 1, wherein the checking module includes an input unit for receiving the one or more ground locations from a user.
11. The apparatus for selecting a ground capacitor according to claim 1, wherein the checking module checks the one or more ground locations from a photo image obtained by photographing the circuit board.
12. The apparatus for selecting a ground capacitor according to claim 1, further comprising: a storing module configured to store resonance frequency information about various kinds of capacitors.
13. A method for selecting a ground capacitor that is connected between a ground of a circuit board included in a battery pack and a vehicle chassis, the method comprising: a checking step for checking one or more ground locations on the circuit board; a selecting step for selecting a reference location on the circuit board, based on the one or more ground locations checked in the checking step; a calculating step for calculating a distance from the reference location selected in the selecting step to a nearest ground location as a reference distance; a computing step for computing a reference frequency by using the reference distance calculated in the calculating step; and a choosing step for choosing a recommended capacitor, based on the reference frequency computed in the computing step.
14. The method for selecting a ground capacitor according to claim 13, wherein the checking step checks locations of a connector terminal and the ground capacitor provided at the circuit board, as the one or more ground locations.
15. The method for selecting a ground capacitor according to claim 13, wherein the selecting step forms a circle around each of the one or more ground locations with the same radius and selects at least a part of a region positioned out of the formed circles and existing on the circuit board as the reference location.
16. The method for selecting a ground capacitor according to claim 15, further comprising: calculating a distance from a center point of two ground locations to each ground location; selecting a minimum distance that is shortest among the calculated distances; identifying a ground location pair where the selected minimum distance is longest; and setting a distance from a center point of the identified ground location pair to the identified ground location pair as the radius.
17. The method for selecting a ground capacitor according to claim 13, wherein the selecting step selects the reference location as a region, and wherein the calculating step calculates a distance from a center point of the region to a nearest ground location as the reference distance.
18. The method for selecting a ground capacitor according to claim 13, wherein the computing step computes a wavelength at the circuit board and a wavelength in air in order by using the reference distance and computes the reference frequency according to the computed wavelength in air.
19. The method for selecting a ground capacitor according to claim 13, wherein the choosing step chooses a capacitor having a lowest parasitic resistance among capacitors having a resonance frequency equal to or lower than the reference frequency as the recommended capacitor.
20. The method for selecting a ground capacitor according to claim 13, the one or more ground locations are received from at least one of: an input unit for receiving the one or more ground locations from a user, or a photo image obtained by photographing the circuit board.
Description
DESCRIPTION OF DRAWINGS
(1) The accompanying drawings illustrate a preferred embodiment of the present disclosure and together with the foregoing disclosure, serve to provide further understanding of the technical features of the present disclosure, and thus, the present disclosure is not construed as being limited to the drawing.
(2)
(3)
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(6)
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(8)
(9)
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BEST MODE
(11) Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Prior to the description, it should be understood that the terms used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present disclosure on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation.
(12) Therefore, the description proposed herein is just a preferable example for the purpose of illustrations only, not intended to limit the scope of the disclosure, so it should be understood that other equivalents and modifications could be made thereto without departing from the scope of the disclosure.
(13) The present disclosure is directed to an apparatus for selecting a ground capacitor. In particular, the grounding capacitor to which the present disclosure is applied is a capacitor provided at a circuit board of a battery pack for a vehicle, which may be a capacitor for grounding, connected to a vehicle chassis.
(14)
(15) Referring to
(16) The circuit board 20 is configured to mount the BMS 30 thereto and may be a printed circuit board (PCB). Thus, various wirings may be printed at the circuit board 20 as current paths. In addition, the circuit board 20 may have a ground. The ground of the circuit board 20 is depicted broadly and indicated by G in
(17) In addition, the circuit board 20 may include a connector terminal 50. The connector terminal 50 may give a terminal for connecting the circuit board to another external device, for example a battery module including a plurality of secondary batteries or an ECU of a vehicle. Moreover, the connector terminal 50 may be connected to the BMS 30 of the circuit board 20.
(18) In particular, the circuit board 20 may include a ground capacitor 10 for grounding. The ground capacitor 10 may be connected between the ground of the circuit board 20 equipped with the BMS 30 and the vehicle chassis. The connection structure of the circuit board 20 and the chassis is schematically shown in
(19) In other words,
(20) Referring to
(21) The ground G of the circuit board 20 may be connected to the chassis 1 by means of the bolt 40 which couples the circuit board 20 and the chassis 1 to each other. At this time, the ground capacitor 10 may be provided between the ground G of the circuit board 20 and the bolt 40. In particular, one end of the ground capacitor 10 may be directly connected to the bolt 40, and the other end of the ground capacitor 10 may be directly connected to the ground G of the circuit board 20.
(22) In addition, the connector terminal 50 provided at the circuit board 20 may include a ground pin as a ground terminal. In addition, the ground pin may be connected to the vehicle chassis 1 via an AUX line or the like. Thus, the ground G of the circuit board 20 and the chassis 1 may be connected to the chassis 1 not only through the bolt 40 but also through the connector terminal 50.
(23) The apparatus for selecting a ground capacitor according to the present disclosure may select a suitable ground capacitor in the configuration as shown in
(24)
(25) Referring to
(26) The checking module 100 may check a ground location on the circuit board. In particular, the checking module 100 may check locations of the connector terminal and the ground capacitor provided at the circuit board as the ground location.
(27)
(28) Referring to
(29) If the ground location is checked on the circuit board by the checking module 100, the checked ground location information may be provided to the selecting module 200.
(30) The selecting module 200 may select a reference location on the circuit board, based on the ground location checked by the checking module 100.
(31) For example, in
(32) Moreover, the selecting module 200 may select, as the reference location, a point on the circuit board that is distant from each ground location a1 to a5 checked by the checking module 100 as uniformly as possible. That is, the selecting module 200 may select the reference location such that the reference location is not excessively close to any one of several ground locations a1 to a5.
(33) In particular, the selecting module 200 may select, as the reference location, a point among the various points on the circuit board, where the shortest distance among the distances from all the ground locations a1 to a5 can be longest. According to this configuration of the present disclosure, when noise is generated by BMS or the like at the circuit board, the noise is not concentrated to a specific ground location, thereby further reducing the ground impedance.
(34) Thus, if the reference location is selected by the selecting module 200, the selected reference location information may be transmitted to the calculating module 300.
(35) The calculating module 300 may calculate a distance from the reference location selected by the selecting module 200 to a nearest ground location as a reference distance.
(36) For example, in
(37) If the reference distance is calculated by the calculating module 300, the calculated reference distance information may be transmitted to the computing module 400.
(38) The computing module 400 may compute a reference frequency using the reference distance calculated by the calculating module 300.
(39) In particular, first, the computing module 400 may compute a wavelength at the circuit board using the reference distance.
(40) For example, the computing module 400 may compute a wavelength range at the circuit board by Equation 1 below.
λ.sub.e=aL Equation 1
(41) Here, λ.sub.e is a wavelength in the circuit board, a is a constant, and L is a reference distance.
(42) In Equation 1, a may be a value that is set so that the effect of noise due to the impedance difference between all the points of the circuit board and the chassis (the ground) is not generated or minimized.
(43) For example, in Equation 1, a may be 20. In this case, Equation 1 may be expressed like Equation 2 below.
λ.sub.e=20L Equation 2
(44) Moreover, the computing module 400 may compute the wavelength in the form of a range. That is, the computing module 400 may compute the wavelength range at the circuit board by using the reference distance.
(45) For example, the computing module 400 may compute the wavelength range at the circuit board by using the reference distance as follows.
λ.sub.e≥20L
(46) In this case, the computing module 400 may compute the wavelength range at the circuit board as 20L or above (here, L is a reference distance). At this time, it may be regarded that electrical lengths from all points of the circuit board to the chassis (the ground) are set to be λ.sub.e/20 or below.
(47) According to this configuration of the present disclosure, the ground impedance may be minimized at various points of the circuit board where noise may be generated. Further, in this case, the noise in the circuit board moves out to the ground out of the circuit board at a distance of λ.sub.e/20 or below, thereby ensuring stable ground characteristics for the circuit board.
(48) The computing module 400 may set a value other than 20 as the a value. For example, the computing module 400 may set a value such as 30 or 40 as the a value. If the a value is increased further as above, the ground impedance may be further reduced.
(49) More specifically, assuming that a is 20 in Equation 1 and the reference distance is calculated as 0.1 m by the calculating module 300, the computing module 400 may compute the wavelength at the circuit board as follows by using Equation 2.
λ.sub.e=2m
(50) That is, the computing module 400 can compute the wavelength at the circuit board as 2 m.
(51) Further, the computing module 400 may represent the wavelength at the circuit board in a range form. Thus, in this case, the wavelength range at the circuit board is λ.sub.e≥2 m, and the computing module 400 may derive a first intermediate result that the wavelength range at the circuit board should be 2 m or above.
(52) If the wavelength at the circuit board is calculated using the reference distance as above, the computing module 400 may compute a wavelength in the air using the same.
(53) For example, the computing module 400 may compute the wavelength in the air using Equation 3 as follows.
(54)
(55) Here, λ is a wavelength in the air, λ.sub.e is a wavelength in the circuit board, and ε.sub.r is a dielectric constant of a dielectric substance in the circuit board.
(56) By using Equation 3 together with Equation 2, λ may be arranged as in Equation 4 below.
λ=20L√{square root over (ε.sub.r)} Equation 4
(57) L is a reference distance that can be calculated by the calculating module 300, and ε.sub.r is a dielectric constant of the circuit board and may be a known value. Thus, the computing module 400 may compute the wavelength (λ) in the air by using Equation 4.
(58) Further, the computing module 400 may compute the wavelength (λ) in the air in a range form. That is, when the computing module 400 computes the wavelength at the circuit board in a range form, the wavelength in the air may also be calculated in a range form.
(59) For example, the computing module 400 may represent the wavelength range in the air as follows by using the above equations.
λ≥20L√{square root over (ε.sub.r)}.
(60) Assuming that the reference distance L is calculated as 0.1 m as in the former embodiment and ε.sub.r is 4, the wavelength range in the air may be calculated as follows.
λ=4m
(61) That is, the computing module 400 may derive a secondary intermediate result that the wavelength in the air is 4 m. Alternatively, the computing module 400 may derive a result that the wavelength in the air should be 4 m or above.
(62) If the wavelength in the air is calculated as above, the computing module 400 may compute a reference frequency according to the calculated wavelength.
(63) In particular, the computing module 400 may compute the reference frequency by using Equation 5 below.
f=c/λ Equation 5
(64) Here, f is the reference frequency, c is the speed of light, and λ is the wavelength in the air.
(65) If the wavelength range in the air is calculated as 4 m or more as in the former embodiment, c is 3×10.sup.8 m/s, so the reference frequency f may be calculated as follows.
f=75 MHz
(66) That is, the computing module 400 may compute the reference frequency as 75 MHz. Moreover, the computing module 400 may compute the reference frequency as a range form as follows by using the above equations.
f≤c/(20L√{square root over (ε.sub.r)})
(67) Here, f is the reference frequency, c is the speed of light, L is the reference distance, and ε.sub.r is a dielectric constant of a dielectric material in the circuit board.
(68) If the reference frequency is computed by the computing module 400 as described above, the computed reference frequency information may be provided to the choosing module 500.
(69) The choosing module 500 may choose a recommended capacitor, based on the reference frequency computed by the computing module 400.
(70) That is, if the reference frequency is computed by the computing module 400, the choosing module 500 chooses one capacitor, in particular a capacitor that allows noise generated from the circuit board to be effectively emitted to the outside, among various kinds of capacitors, and provide the capacitor to the user.
(71) In this case, it is desirable that the specification information of various kinds of capacitors are stored in advance in the apparatus for selecting a ground capacitor according to the present disclosure.
(72) For this, the apparatus for selecting a ground capacitor according to the present disclosure may further include a storing module 600 as shown in
(73) The storing module 600 may store information about various kinds of capacitors in advance. In particular, the storing module 600 may further store resonance frequency information about various kinds of capacitors.
(74)
(75) Referring to
(76) The choosing module 500 may access the storing module 600 and choose an appropriate kind of capacitor by means of the information stored in the storing module 600 as above.
(77) In particular, the choosing module 500 may choose a capacitor having a resonance frequency equal to or lower than the reference frequency as a recommended capacitor.
(78) For example, if the reference frequency computed by the computing module 400 is 75 MHz as in the former embodiment, the choosing module 500 may choose a capacitor having a resonance frequency smaller than 75 MHz as a recommended capacitor. Further, if many capacitors have a resonance frequency equal to or lower than the reference frequency among the capacitors whose information is stored in the storing module 600, the choosing module 500 may choose one of these capacitors and provide only the information about the capacitor to the user.
(79) For example, if the reference frequency is 75 MHz, in
(80) Here, the choosing module 500 may choose a capacitor whose resonance frequency is closest to the reference frequency as a recommended capacitor, among the capacitors having a resonance frequency lower than the reference frequency.
(81) For example, in
(82) As described above, by using a capacitor whose resonance frequency is close to the reference frequency, it is possible to increase a frequency band that maintains low ground impedance.
(83) In addition, when there are a lot of capacitors having a resonance frequency equal to or lower than the reference frequency, the choosing module 500 may choose a recommended capacitor in consideration of a parasitic resistance (ESR). In particular, the choosing module 500 may choose a capacitor having a lowest parasitic resistance as a recommended capacitor, among the capacitors having a resonance frequency equal to or lower than the reference frequency.
(84) For example, in
(85) According to this configuration of the present disclosure, the noise emission effect may be maximized by minimizing the ground impedance.
(86) In particular, the choosing module 500 may be configured to consider the resonance frequency firstly and the parasitic resistance secondly in regard to the capacitors having a resonance frequency lower than the reference frequency.
(87) For example, in the embodiment of
(88) However, in the embodiment of
(89) Preferably, the selecting module 200 forms a circle having the same radius around each ground location and select at least a part of a region located outside the formed circles and existing on the circuit board as a reference location.
(90)
(91) Referring to
(92) If five circles d1 to d5 are drawn corresponding to five ground locations as above, the selecting module 200 may find a region on the circuit board that does not belong to any of the five circles. Seeing
(93) Here, the reference location may be a single point or a predetermined region having a certain area. For example, in
(94) According to this configuration of the present disclosure, a region located at approximately equal distance from each ground location without shifting to any one ground location may be easily found. That is, the process of selecting a point as far as possible from all the ground locations as a reference location may be easily performed.
(95) In the configuration where a reference location is selected using a circle, the selecting module 200 may set the radius r of the circle by using a center point of two ground locations. More specifically, the selecting module 200 may calculate a distance from the center point of two ground locations to each ground location and select a minimum distance that is shortest among the calculated distances. After that, the selecting module 200 may identify a ground location pair that has a longest minimum distance among the selected minimum distances and set a distance from the center point of the identified ground location pair to the identified ground location pair as the radius r of the circle. This will be described in more detail with reference to
(96)
(97) Referring to
(98) If the center point of each ground location pair is found as above, the selecting module 200 calculates a distance from each center point to every the ground location and select a shortest distance therefrom. This will be described in more detail with reference to
(99)
(100) Referring to
(101) For example, the selecting module 200 may calculate distances from the center point f12 to the ground locations a1 to a5, respectively, determine a distance g1 to the ground location a2 as a shortest distance among them, and select the distance g1 as a shortest distance to the center point f12. However, since the center point f12 is a center point of the ground locations a1 and a2, the distances from the center point f12 to the ground locations a1 to a2 are the same, and thus only the distance to the ground location a2 is depicted in
(102) The selecting module 200 may also select a shortest distance for all of the other seven center points f14, f23, f24, f25, f34, f35, f45 in this manner. In addition, for each center point, the selecting module 200 may select a shortest distance as the distance g6 for the center point f14, the distance g5 for the center point f23, the distance g10 for the center point f24, the distance g8 for the center point f25, the distance g7 for the center point f34, the distance g4 for the center point f35, and the distance g9 for the center point f45.
(103) The selecting module 200 may determine a longest distance among the shortest distances g1 to g10 for each center point selected as above. For example, seeing
(104) In this case, the selecting module 200 may set the determined shortest distance g1 as a radius of the circle. That is, the selecting module 200 may draw a circle for each ground location as shown in
(105) Meanwhile, the selecting module 200 may select the reference location as a region form.
(106) For example, the selecting module 200 may select the reference location in a region form having a predetermined area as indicated by e in
(107) In this case, the calculating module 300 may calculate a distance from the center point of the region to a nearest ground location as a reference distance. Here, the center point may be set in various ways such as the center of gravity.
(108) For example, the calculating module 300 may select a center point of the region indicated by e in
(109) Also preferably, the checking module 100 may include an input unit for receiving a ground location from a user.
(110) For example, the checking module 100 may include a mouse, a keyboard and/or a monitor as the input unit. In this case, the user may use the input unit to input the ground locations a1 to a5.
(111) According to this configuration of the present disclosure, the checking module 100 does not need to directly check the ground locations since the reference location may be selected using the ground locations input by the user.
(112) Also preferably, the checking module 100 may directly check the ground locations on the circuit board. In particular, the checking module 100 may check the ground locations from a photo image obtained by photographing the circuit board. For this, the checking module 100 may include a photographing unit such as a camera for photographing the circuit board.
(113) For example, the checking module 100 may photograph an upper portion of the circuit board equipped with the BMS as shown in
(114) In this case, the checking module 100 may check the ground locations by identifying the ground capacitor and the connector terminals from the top image.
(115) Alternatively, the checking module 100 may provide the photographed image to the monitor and allow the user to directly select the ground locations through the input unit.
(116)
(117) As shown in
(118) The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the disclosure, are given by way of illustration only, since various changes and modifications within the scope of the disclosure will become apparent to those skilled in the art from this detailed description.
(119) Meanwhile, in this specification, the term ‘module’ is used, such as ‘a checking module’, ‘a selecting module’, ‘a calculating module’, ‘a computing module’ and ‘a choosing module’. However, it will be apparent to those skilled in the art that this term just represents a logical configuration unit and is not intended to represent a component that must be physically separable or physically separated.
(120) That is, each component in the present disclosure corresponds to a logical component for realizing a technical idea of the present disclosure. Thus, even though the components are integrated or separated, it should be interpreted as falling within the scope of the present disclosure as long as the function of the logical component of the present disclosure can be performed. Also, any element performing the same or similar function should be construed as being within the scope of the present disclosure irrespective of the conformity of the name.
REFERENCE SIGNS
(121) 1: chassis 10: ground capacitor 20: circuit board 30: BMS 40: bolt 50: connector terminal 100: checking module 200: selecting module 300: calculating module 400: computing module 500: choosing module 600: storing module