U.S. patent application number 15/671708 was filed with the patent office on 2017-11-23 for circuit for protecting battery for electric vehicle and driving method thereof.
The applicant listed for this patent is HYUNDAI MOTOR COMPANY, KIA MOTORS CORPORATION. Invention is credited to Jun Seok CHOI, Hee Sung MOON, Woo Jin SHIN.
Application Number | 20170334308 15/671708 |
Document ID | / |
Family ID | 53482981 |
Filed Date | 2017-11-23 |
United States Patent
Application |
20170334308 |
Kind Code |
A1 |
MOON; Hee Sung ; et
al. |
November 23, 2017 |
CIRCUIT FOR PROTECTING BATTERY FOR ELECTRIC VEHICLE AND DRIVING
METHOD THEREOF
Abstract
A circuit for protecting a battery for an electric vehicle
includes a high voltage battery configured to output a DC voltage,
an inverter configured to selectively receive the DC voltage from
the high voltage battery and invert the DC voltage into an AC
voltage when the inverter receives the DC voltage, a relay disposed
between the high voltage battery and the inverter and configured to
selectively block the DC voltage from the high voltage battery to
the inverter, and a battery management system including a microchip
configured to output a main relay control signal for controlling
the relay. The battery management system is configured to receive
the DC voltage from the high voltage battery, and output a voltage
relay control signal controlling the relay separately from the
control by the microchip.
Inventors: |
MOON; Hee Sung;
(Hwaseong-si, KR) ; CHOI; Jun Seok; (Suwon-si,
KR) ; SHIN; Woo Jin; (Seoul, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HYUNDAI MOTOR COMPANY
KIA MOTORS CORPORATION |
Seoul
Seoul |
|
KR
KR |
|
|
Family ID: |
53482981 |
Appl. No.: |
15/671708 |
Filed: |
August 8, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14460091 |
Aug 14, 2014 |
9758051 |
|
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15671708 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60L 3/0046 20130101;
B60L 50/51 20190201; B60L 2240/547 20130101; Y02T 10/70 20130101;
B60L 3/04 20130101; B60L 3/12 20130101; B60L 58/15 20190201 |
International
Class: |
B60L 11/18 20060101
B60L011/18; B60L 3/12 20060101 B60L003/12; B60L 3/00 20060101
B60L003/00; B60L 3/04 20060101 B60L003/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 27, 2013 |
KR |
10-2013-0165488 |
Claims
1. A method of protecting a battery for an electric vehicle, which
comprises a high voltage battery, an inverter for inverting a
voltage of the high voltage battery, a relay for selectively
blocking a voltage from the high voltage battery to the inverter,
and a battery management system for controlling the relay, the
method comprising: receiving a voltage from the high voltage
battery; comparing the received voltage of the battery with a
reference voltage; and opening the relay when the battery voltage
is higher than the reference voltage.
2. The method of claim 1, wherein the comparing of the received
voltage of the battery with the reference voltage includes
comparing the voltage through an OP AMP comparator disposed inside
or outside the battery management system.
3. The method of claim 2, wherein: the OP AMP comparator outputs 0
V when the received voltage of the high voltage battery is higher
than the reference voltage of the battery management system, and
the OP AMP comparator outputs a predetermined voltage when the
received voltage of the high voltage battery is lower than or equal
to the reference voltage of the battery management system.
4. A method of protecting a battery for an electric vehicle, which
comprises a high voltage battery, an inverter for inverting a
voltage of the high voltage battery, a relay for selectively
blocking a voltage from the high voltage battery to the inverter,
and a battery management system for controlling the relay, the
method comprising: receiving a voltage from the high voltage
battery; comparing the received battery voltage with a reference
voltage through an operational amplifier (OP AMP) comparator
connected with the battery management system, and outputting a
voltage relay control signal based on a result of the comparison;
outputting a main relay control signal through a microchip of the
battery controller; and controlling the relay based on at least one
of the voltage relay control signal and the main relay control
signal.
5. The method of claim 4, wherein the controlling of the relay
based on at least one of the voltage relay control signal and the
main relay control signal comprises: inputting the main relay
control signal and the voltage relay control signal to an AND gate
of the battery management system as an input signal; and inputting
an output signal of the AND gate to the relay as a control
signal.
6. The method of claim 5, wherein: the voltage relay control signal
is 0 V when the received voltage from the high voltage battery is
higher than the reference voltage of the battery management system
according to the comparison by the OP AMP comparator, and the
voltage relay control signal is a predetermined voltage when the
received voltage from the high voltage battery is equal to or lower
than the reference voltage of the battery management system.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional patent application of U.S.
patent application Ser. No. 14/460,091, filed on Aug. 14, 2014
which claims benefit of priority to Korean Patent Application No.
10-2013-0165488 filed in the Korean Intellectual Property Office on
Dec. 27, 2013, the entire contents of which are incorporated herein
by reference.
TECHNICAL FIELD
[0002] The present inventive concept relates to a method of
protecting a battery for an electric vehicle, and more
particularly, to a circuit and a method of protecting a battery for
an electric vehicle, which are capable of controlling a relay with
a voltage of a battery by installing an operational amplifier (OP
AMP) circuit inside and outside a battery management system (BMS)
in order to maintain the control of the relay even when the battery
for the electric vehicle has a high voltage due to an operation
problem or overcharging.
BACKGROUND
[0003] In general, a high voltage battery is used in a hybrid
vehicle or an electric vehicle as a part or all of a power source.
In order to protect the high voltage battery, a high voltage relay
needs to be used.
[0004] The high voltage battery is mounted on a vehicle in a form
of one pack by serially connecting about 50 to 100 cells according
to a necessary capacity of the battery. The high voltage battery
pack has excellent energy density and efficiency, but when the high
voltage battery pack is overcharged, there is a risk in that the
high voltage battery pack is inflated or exposed, so that a battery
management system (BMS) controls a high voltage relay.
[0005] That is, when the BMS monitors a sum of the voltages of the
entire cells or the voltage of the battery pack, and the sum of the
voltages of the entire cells or the voltage of the battery pack is
equal to or larger than a reference voltage, the BMS compulsorily
opens the relay to prevent the battery from being charged any more,
or outputs zero as an available voltage so as to prevent another
system from being damaged.
[0006] However, since the BMS controls the relay only with a
control signal through a microchip therein, when the BMS has a
problem due to a vehicle accident, or an erroneous operation of a
BMS electronic system is perormed, the relay is not properly
controlled, so that there is still a risk that the battery may
catch on fire or explode.
[0007] The above information disclosed in this Background section
is only for enhancement of understanding of the background of the
inventive concept and therefore it may contain information that
does not form the prior art that is already known in this country
to a person of ordinary skill in the art.
SUMMARY
[0008] The present inventive concept has been made in an effort to
provide a circuit and a method of protecting a battery for an
electric vehicle, which are capable of controlling a relay even
with a voltage of a battery by installing an OP AMP inside or
outside a BMS, as well as a BMS control signal, in order to
maintain the control of the relay even when the battery for the
electric vehicle has a high voltage due to an operation problem or
overcharging.
[0009] One aspect of the present inventive concept relates to a
circuit for protecting a battery for an electric vehicle, including
a high voltage battery configured to output a DC voltage, an
inverter configured to selectively receive the DC voltage from the
high voltage battery, and invert the DC voltage into an AC voltage
when the inverter receives the DC voltage, a relay disposed between
the high voltage battery and the inverter and configured to
selectively block the DC voltage from the high voltage battery to
the inverter between the high voltage battery and the inverter, and
a battery management system including a microchip confugred to
output a main relay control signal for controlling the relay, and
configured to receive the DC voltage from the high voltage battery
and output a voltage relay control signal controlling the relay
separately from the control by the microchip.
[0010] The battery management system may further include an
operational amplifier (OP AMP) comparator disposed inside or
outside thereof in order to output the voltage relay control
signal.
[0011] The OP AMP comparator may compare an input voltage of the
high voltage battery with a reference voltage of the battery
management system, and outputs a voltage relay control signal
according to a result of the comparison.
[0012] When the input voltage of the high voltage battery is higher
than the reference voltage of the battery management system, the OP
AMP comparator may output 0 V, and when the input voltage of the
high voltage battery is lower than or equal to the reference
voltage of the battery management system, the OP AMP comparator may
output a predetermined voltage.
[0013] The OP AMP comparator may include two or more OP AMPs,
including a first OP AMP configured to compare a voltage, and a
second OP AMP configured to invert an output voltage of the first
OP AMP.
[0014] The battery management system may further include an AND
gate, and the voltage relay control signal and the main relay
control signal may be input to the AND gate, and an output signal
of the AND gate may be inputted to the relay.
[0015] Another aspect of the present inventive concept encompasses
a method of protecting a battery for an electric vehicle, which
comprises a high voltage battery, an inverter for inverting a
voltage of the high voltage battery, a relay for selectively
blocking a voltage from the high voltage battery to the inverter,
and a battery management system for controlling the relay, the
method including receiving a voltage from the high voltage battery.
The received voltage of the battery is compared with a reference
voltage. The relay is opened when the battery voltage is higher
than the reference voltage.
[0016] In the comparing of the received voltage of the battery and
the reference voltage, the voltage may be compared through an OP
AMP comparator disposed inside or outside the battery management
system.
[0017] When the received voltage of the high voltage battery is
higher than the reference voltage of the battery management system,
the OP AMP comparator may output 0 V, and when the received voltage
of the high voltage battery is lower than or equal to the reference
voltage of the battery management system, the OP AMP comparator may
output a predetermined voltage.
[0018] Yet another aspect of the present inventive concept relates
to a method of protecting a battery for an electric vehicle, which
comprises a high voltage battery, an inverter for inverting a
voltage of the high voltage battery, a relay for selectively
blocking a voltage from the high voltage battery to the inverter,
and a battery management system for controlling the relay, the
method including receiving a voltage from the high voltage battery.
The received battery voltage is compared with a reference voltage
through an operational amplifier (OP AMP) comparator connected with
the battery management system, and a voltage relay control signal
is outputted based on a result of the comparison. A main relay
control signal is outputted through a microchip of the battery
controller. The relay is controlled based on at least one of the
voltage relay control signal and the main relay control signal.
[0019] In the controlling of the relay based on at least one of the
voltage relay control signal and the main relay control signal, the
main relay control signal and the voltage relay control signal may
be inputted to an AND gate of the battery management system as an
input signal, and an output signal of the AND gate may be inputted
to the relay as a control signal.
[0020] When the received voltage from the high voltage battery is
higher than the reference voltage of the battery management system
according to the comparison by the OP AMP comparator, the voltage
relay control signal may be 0 V, and when the received voltage from
the high voltage battery is lower than or equal to the reference
voltage of the battery management system, the voltage relay control
signal may be a predetermined voltage.
[0021] As described above, according to the the present inventive
concept, even when a battery for an electric vehicle has a high
voltage due to an operation problem or overcharging, it is possible
to control the relay with a battery voltage through the OP AMP
connected with the BMS, as well as a BMS control signal, so that a
relay control signal is dualized, thereby more effectively
controlling the relay.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a block diagram illustrating a circuit for
protecting a battery for an electric vehicle according to an
exemplary embodiment of the present inventive concept.
[0023] FIG. 2 is a circuit diagram configuring an OP AMP in a
circuit for protecting a battery for an electric vehicle according
to an exemplary embodiment of the present inventive concept.
[0024] FIG. 3 is a table illustrating a process of converting a
main relay control signal of a microchip and a voltage relay
control signal of an OP AMP comparator into a final relay control
signal by passing through an AND gate according to an exemplary
embodiment of the present inventive concept.
[0025] FIG. 4 is a flowchart illustrating a method of protecting a
battery for an electric vehicle according to an exemplary
embodiment of the present inventive concept.
DETAILED DESCRIPTION
[0026] In the following detailed description, only certain
exemplary embodiments of the present inventive concept have been
shown and described, simply by way of illustration. As those
skilled in the art would realize, the described embodiments may be
modified in various different ways, all without departing from the
spirit or scope of the present inventive concept.
[0027] Through the specification, unless explicitly described to
the contrary, the word "comprise" and variations such as
"comprises" or "comprising", will be understood to imply the
inclusion of stated elements but not the exclusion of any other
elements.
[0028] Like reference numerals designate like constituent elements
throughout the specification.
[0029] In the present specification and the claims, it shall be
appreciated that an electric vehicle is all of the vehicles using
electricity as a power source, such as a plug in hybrid electric
vehicle (PHEV) or hybrid electric vehicle (HEV) using electricity
as a part of a power source, as well as an electric vehicle (EV)
using electricity as the entirety of a power source.
[0030] Hereinafter, exemplary embodiments of the present inventive
concept will be described in detail with reference to the
accompanying drawings.
[0031] FIG. 1 is a block diagram illustrating a circuit for
protecting a battery for an electric vehicle according to an
exemplary embodiment of the present inventive concept.
[0032] Referring to FIG. 1, the circit for protecting the battery
for an electric vehicle according to an exemplary embodiment of the
present inventive concept may include a high voltage battery 100, a
battery management system (BMS) 200, a relay 300, and an inverter
400.
[0033] The high voltage battery 100 may be a battery such as a
nickel metal battery and a lithium ion battery, used in an electric
vehicle, and may be mounted inside the electric vehicle to serve to
supply power to a driving motor. The high voltage battery 100 may
be a pack form of battery cells, which are arranged in series or in
parallel, and may be formed of several sub packs. Accordingly, the
high voltage battery 100 may be all of the high voltage batteries
including a battery pack used in the electric vehicle.
[0034] The BMS 200 may manage the high voltage battery 100, and
when the high voltage battery 100 is overcharged by controlling the
relay 300, the BMS 200 may prevent the power of the high voltage
battery 100 from flowing toward the inverter 400.
[0035] As illustrated in FIG. 1, the BMS 200 according to an
exemplary embodiment of the present inventive concept may include
an OP AMP comparator 210 and a microchip 220.
[0036] The OP AMP comparator 210 may be formed of an OP AMP
circuit, and may compare a voltage received from the high voltage
battery 100 with a reference voltage of the BMS 200, and the
microchip 220 may perform a unique operation performed by the BMS
200.
[0037] The OP AMP comparator 210 may be used while a high voltage
and a low voltage may be simultaneously connected, so that
insulation may be maintained by installing a photo coupler, and the
like.
[0038] As illustrated in FIG. 1, the OP AMP comparator 210 may be
additionally installed in a circuit inside the BMS 200, and in
another exemplary embodiment of the present inventive concept, the
OP AMP comparator 210 may also be installed outside the BMS 200 by
using a separate circuit. Accordingly, the OP AMP comparator 210
may be all of the circuits which may be installed to be connected
with the BMS 200.
[0039] FIG. 2 is a circuit diagram configuring the OP AMP
comparator 210 in the circuit for protecting the battery for the
electric vehicle according to an exemplary embodiment of the
present inventive concept.
[0040] As illustrated in FIG. 2, the OP AMP comparator 210 may use
two or more OP AMP circuits. The circuit for protecting the battery
for the electric vehicle according to an exemplary embodiment of
the present inventive concept may use two OP AMP circuits.
[0041] A first OP AMP circuit among them may compare a voltage, and
a second OP AMP circuit may reverse an output voltage in order to
output a value of the voltage according to a result of the
comparison by the first OP AMP circuit.
[0042] The first OP AMP circuit may output zero as an output
voltage when the voltage of the high voltage battery 100 exceeds
the reference voltage of the BMS 200, and may output a
predetermined voltage when the voltage of the high voltage battery
100 is smaller than or equal to the reference voltage of the BMS
200.
[0043] Accordingly, the BMS 200 may simultaneously output a voltage
relay control signal from the OP AMP comparator 210 and a main
relay control signal from the microchip 220. To this end, the BMS
200 may be implemented by one or more processors operated by a set
program, and the set program may be programmed so as to perform
each step of a method of protecting a battery for an electric
vehicle according to an exemplary embodiment of the present
inventive concept.
[0044] Referring to FIG. 1, the relay 300 may be positioned between
the high voltage battery 100 and the inverter 400 to serve to
protect the high voltage battery 100.
[0045] An AND gate 230 may be installed at a front end of the relay
300, so that the voltage relay control signal and the main relay
control signal inputted to the relay 300 pass through the AND gate
230.
[0046] FIG. 3 is a table illustrating a process of converting the
main relay control signal of the microchip 220 and the voltage
relay control signal of the OP AMP comparator 210 into a final
relay control signal by passing through the AND gate 230 according
to an exemplary embodiment of the present inventive concept.
[0047] As illustrated in FIG. 3, the relay 300 may be closed only
when both the voltage relay control signal from the OP AMP
comparator 210 and the main relay control signal from the microchip
220 maintain the relay 300 to be in a closed state. That is, when
the voltage relay control signal and the main relay control signal
output a signal (for example, 1) for closing the relay 300, a final
relay control signal passing through the AND gate may make the
relay 300 be maintained in the closed state.
[0048] In the meantime, when any one of the voltage relay control
signal or the main relay control signal opens the relay, the high
voltage battery 100 may be protected by opening the relay 300. That
is, when any one of the voltage relay control signal or the main
relay control signal outputs a signal (for example, 00) for opening
the relay, the final relay control signal passing through the AND
gate may open the relay.
[0049] The inverter 400 may serve to convert a DC voltage into a
three-phase AC voltage for driving a motor, and may generally
include a switching element, a transistor, and a gate driver for
supplying a signal to the switching element.
[0050] When the relay 300 is opened, the electrical connection
between the inverter 400 and the high voltage battery 100 may be
cut, so that the high voltage battery 100 is protected.
[0051] Hereinafter, a method of protecting a battery for an
electric vehicle according to an exemplary embodiment of the
present inventive concept will be described with reference to FIG.
4.
[0052] FIG. 4 is a flowchart illustrating a method of protecting a
battery for an electric vehicle according to an exemplary
embodiment of the present inventive concept.
[0053] As illustrated in FIG. 4, the method of protecting a battery
for an electric vehicle according to an exemplary embodiment of the
present inventive concept may begin by receiving a voltage from the
high voltage battery 100 (S100).
[0054] When the BMS 200 receives the voltage from the high voltage
battery 100, the OP AMP comparator 210 connected with the BMS 200
may compare the received battery voltage with a reference voltage
(S110).
[0055] When the received battery voltage exceeds the reference
voltage, the BMS 200 may output 0 V, and when the received battery
voltage is smaller than or equal to the reference voltage, the BMS
200 may output a predetermined voltage in step S110.
[0056] When the received battery voltage exceeds the reference
voltage in step S110, the BMS 200 may control the relay to be
opened (S120). That is, when the high voltage battery 100 has a
high voltage due to an operation problem or overcharging, the BMS
200 may open the relay to protect the high voltage battery 100.
[0057] The BMS 200 may determine whether a relay request is
generated by the microchip 220 (S130) while simultaneously
performing step S110. The step of determining whether the relay
request is generated may be operated according to an existing relay
control technology.
[0058] When it is determined in step S130 that the relay request is
generated, the BMS 200 may control the relay to be opened (S140)
similar to step S120.
[0059] That is, when any one of the case where the received battery
voltage exceeds the reference voltage in step S110 and the case
where the relay request is generated in step S130 is satisfied, the
BMS 200 may control the relay to be opened.
[0060] However, when the received battery voltage is smaller than
or equal to the reference voltage in step S110 and the relay
request is not generated in step S130, the BMS 200 may not
separately control the relay and may make the relay be maintained
in the closed state.
[0061] When the BMS performs the control of the relay in step S140,
the method of protecting the battery for the hybrid or electric
vehicle according to an exemplary embodiment of the present
inventive concept may be terminated. Accordingly, it is possible to
protect the high voltage battery 100 from a problematic state, such
as the operation problem or the overcharging.
[0062] While this inventive concept has been described in
connection with what is presently considered to be practical
exemplary embodiments, it is to be understood that the inventive
concept is not limited to the disclosed embodiments, but, on the
contrary, is intended to cover various modifications and equivalent
arrangements included within the spirit and scope of the appended
claims.
* * * * *