KR102030823B1 - Battery management system and operating method thereof - Google Patents

Abstract

The battery management system according to the present invention includes a sensing integrated circuit that monitors a voltage of each of the battery cells connected to a busbar, a voltage measured at both ends of the busbar, and determining whether the measured voltage is within an input voltage range. And a voltage protection circuit outputting the measured voltage to the input pins of the sensing integrated circuit when the measured voltage is within a normal range.

Description

BATTERY MANAGEMENT SYSTEM AND OPERATING METHOD THEREOF}

The present invention relates to a battery management system and a method of operation thereof.

In vehicles using electric energy, the performance of the battery directly affects the performance of the vehicle, so that not only the battery cell's voltage, the voltage and current of the entire battery are measured, but also the charge and discharge of each battery cell is efficiently managed. There is a need for a battery management system (BMS) that monitors the state of a cell sensing integrated circuit (IC) that senses each battery cell and enables stable control of the cell. BACKGROUND In general, a vehicle battery management system (BMS) includes a MICOM and a plurality of cell sensing integrated circuits (ICs) for monitoring battery cells.

Publication No. 10-2017-0069619, published date: June 21, 2017, title of the invention: a battery management system and its voltage measuring method. Patent No. 10-1665003, registered date: October 05, 2016, title of the invention: Apparatus and method for overvoltage protection of a battery busbar. United States Patent Application Publication: 2014-0285936, Publication Date: September 25, 2014, Title of the invention: BATTERY MANAGEMENT SYSTEM FOR ELECTRIC VEHICLE.

SUMMARY OF THE INVENTION An object of the present invention is to provide a battery management system for protecting a sensing IC from overvoltage / reverse voltage of a busbar and a method of operating the same.

Battery management system according to an embodiment of the present invention, the sensing integrated circuit for monitoring the voltage of each of the battery cells connected to the bus bar; And measure the voltage across the busbar in parallel between the busbar and the sensing integrated circuit, determine whether the measured voltage is within an input voltage range, and wherein the measured voltage is greater than or equal to a first reference value. When less than 2 reference values, it may include a voltage protection circuit for changing the measured voltage to a voltage within the input voltage range to output to the input pins of the sensing integrated circuit.

In example embodiments, when the measured voltage is within the input voltage range, the voltage protection circuit may output the measured voltage to the input pins.

In example embodiments, the voltage protection circuit may turn on a relay connected to the bus bar in parallel to change the measured voltage into a voltage within the input voltage range.

In some embodiments, as the relay is turned on, a parallel resistance is connected to the busbar, thereby reducing the measured voltage to a voltage within the input voltage range.

The voltage protection circuit may include: a first voltage meter configured to measure a voltage across the busbar; A second voltage meter for measuring a voltage across the busbar; A first comparator for comparing an output value of the first voltage meter and a first reference value; A second comparator for comparing an output value of the second voltage meter and a second reference value; And a logic circuit configured to logically calculate an output value of the first comparator and an output value of the first comparator, wherein the relay may be turned on according to the output value of the logic circuit.

The first comparator may include a positive input terminal receiving the first reference value and a negative input terminal receiving the output value of the first voltage meter, and the second comparator receiving the output value of the second voltage meter. It may include a positive input terminal and a sound input terminal for receiving the second reference value.

In an embodiment, the first reference value may be a reference value for determining an overvoltage, and the second reference value may be a reference value for determining a reverse voltage.

In example embodiments, the relay may be turned on according to a result of the logic circuit to connect the input pins of the sensing integrated circuit.

In example embodiments, the logic circuit may perform a NAND operation.

A method of operating a battery management system according to an exemplary embodiment of the present disclosure includes: measuring a voltage at both ends of a bus bar by placing a bus bar and a sensing integrated circuit in parallel; Determining whether the measured voltage is out of the normal range; And when the measured voltage is greater than or equal to a first reference value or less than or equal to a second reference value, converts the measured voltage into a voltage within the normal range and outputs the output voltage to input pins of the sensing integrated circuit to protect the circuit for the sensing integrated circuit. It may include the step of performing.

In an embodiment, the determining whether the deviation is from the normal range may include: determining whether the measured voltage is equal to or greater than the first reference value; And determining whether the measured voltage is less than or equal to the second reference value.

The performing of the circuit protection operation may include lowering the measured voltage to a voltage within the normal range by turning on a relay connected to the bus bar in parallel.

The method may further include outputting the measured voltage to the input pins of the sensing integrated circuit if the measured voltage is within the normal range.

In an embodiment, when the measured voltage does not deviate from the normal range, it may be entered into the step of measuring the voltage across the busbar.

According to an embodiment of the present invention, a battery management system and a method of operating the battery management system according to an exemplary embodiment of the present invention use an voltage range, a comparator, a relay, or the like to protect a sensing IC in an abnormal wiring state of a bus bar. By turning on the relay, the range of voltage input to the sensing IC can be limited. As a result, the sensing IC can be protected from overvoltage / reverse voltage of the busbar.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are provided to assist in understanding the present embodiment, and provide embodiments with a detailed description. However, the technical features of the present embodiment are not limited to the specific drawings, and the features disclosed in the drawings may be combined with each other to constitute a new embodiment.
1 is a diagram illustrating a battery management system according to an exemplary embodiment of the present invention.
2 is a diagram illustrating a voltage protection circuit according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating an output waveform of the logic circuit NAND 135 illustrated in FIG. 2.
4 is a diagram illustrating a method of protecting a sensing IC from busbar overvoltage / reverse voltage of a battery management system according to an exemplary embodiment of the present disclosure.
5 is a diagram illustrating a battery management system according to another exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION Hereinafter, the contents of the present invention will be described clearly and in detail so that those skilled in the art can easily implement the drawings.

As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Terms such as first and second may be used to describe various components, but the components should not be limited by the terms.

The terms may be used for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that another component may be present in the middle. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

Other expressions describing the relationship between components, such as "between" and "immediately between" or "neighboring to" and "directly neighboring", should be interpreted as well. The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

In this application, the terms "comprise" or "having" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof that is implemented, and that one or more other features or numbers are present. It should be understood that it does not exclude in advance the possibility of the presence or addition of steps, actions, components, parts or combinations thereof. Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. .

1 is a diagram illustrating a battery management system 100 according to an embodiment of the present invention. The battery management system 100 may include sensing integrated circuits (ICs) 110 and 120, and a voltage protection circuit 130.

 Each of the sensing integrated circuits 110, 120 may be implemented to monitor each battery cell of battery cells connected in series in a corresponding battery pack 210 or 220. In FIG. 1, two battery packs 210 and 220 are illustrated for convenience of description, but it should be understood that the number of battery packs of the present invention is not limited thereto. In addition, although each of the battery packs 210 and 220 shown in FIG. 1 is composed of four series connected battery cells, it should be understood that the number of battery cells of the present invention is not limited thereto.

Generally, there is a bus bar 215 for the connection (electrical and physical) between the battery packs 210, 220. The busbar 215 may be implemented with a metal material. In an embodiment, the busbar 215 may have a resistance component of several mΩ, such as a conductor self-resistance or a contact resistance connecting the battery cells to each other.

A + 200A current can flow through the busbar 215 when the vehicle motor is driven, or -200A current can flow when the battery is charged. Therefore, the forward / reverse voltage of several V may occur due to the resistance component of the busbar 215.

The voltage protection circuit 130 may be implemented to monitor a voltage across the busbar 215 and perform a circuit protection operation to protect the sensing IC 120 when the monitoring voltage is overvoltage / reverse voltage. For example, when the voltage across the busbar 215 between the first node N1 and the second node N2 is greater than or equal to a predetermined overvoltage / reverse voltage, the voltage protection circuit 130 monitors the monitored result value. In accordance with this, the input pins 121 and 122 of the sensing IC 120 may be electrically connected or disconnected.

Although not shown, the battery management system 100 may include a battery management system (BMS) controller having a MICOM. The microcomputer may be implemented to control the overall operation of the BMS controller. In an embodiment, the microcomputer may include a microcontroller (MCU). In addition, the microcomputer receives the monitoring result values from the sensing ICs 110 and 120, and comprehensively diagnoses a battery failure by using the received result values, driving conditions, total battery voltage, and whether or not the motor is controlled, and supplies power according to the diagnosis result. The supply circuit can be controlled. For example, microcomputer algorithms (over voltage, under voltage, over temperature, over current, under current, open load, etc.) algorithm (software / firmware) Can be judged based on

The battery management system 100 according to an embodiment of the present invention measures the voltage across the busbar 215, determines whether the measured voltage is within the input voltage range, and measures when the measured voltage is within the normal range. Output voltage to the input pins 121 and 122 of the sensing IC 120 or when the measured voltage is out of the normal range, the measured voltage is lowered and the lower voltage is input pins 121 and 122 of the sensing integrated circuit 120. By providing the voltage protection circuit 130 to output the circuit, the sensing IC 120 can be protected from abnormalities of the bus bar 215, that is, overvoltage / reverse voltage.

2 is a diagram illustrating a voltage protection circuit 130 according to an embodiment of the present invention. Referring to FIG. 2, the voltage protection circuit 130 may include first and second voltage meters U1 and U2 131 and 132, first and second comparators U3 and U4 133 and 134, and a logic circuit. (NAND) 135, and a relay 136.

The first voltage meter 131 includes a positive input terminal (+) connected to a first node (N1) and a negative input terminal (-) connected to a second node (N2), and includes a first node (N1) and a second node ( The voltage difference of N2) can be output.

The second voltage meter 132 includes a positive input terminal (+) connected to the first node N1 and a negative input terminal (−) connected to the second node N2, and includes a first node N1 and a second node ( The voltage difference of N2) can be output.

 The first comparator 133 may include a positive input terminal (+) receiving a first reference value VHI and a negative input terminal (−) receiving an output value of the first voltage meter 131. In an embodiment, the first reference value VHI may be an overvoltage determination level of the bus bar 215. That is, the first reference value VHI may be an upper limit value of the voltage input to the sensing IC 120.

The second comparator 134 may include a positive input terminal (+) for receiving an output value of the second voltage meter 132 and a negative input terminal (−) for receiving a second reference value (VLO). The second reference value VLO may be a reverse voltage determination level of the bus bar 215. . That is, the second reference value VLO may be a lower limit value of the voltage input to the sensing IC 120.

The logic circuit 135 may be implemented to NAND the output value of the first comparator 133 and the output value of the second comparator 134.

The relay 136 may be implemented to electrically connect the first input pin 121 and the second input pin 122 according to the output value of the logic circuit 135. In an embodiment, the relay 136 may include a photo relay. The photo relay may be implemented as a photomos relay, a photo coupler, or the like. However, it should not be understood that the configuration of the relay of the present invention is limited to the photo relay.

The battery management system 100 according to an exemplary embodiment of the present invention may provide voltage measuring devices 131 and 132, comparators 133 and 134, and a relay to protect the sensing IC 120 in an abnormal connection state of the busbar 215. When a voltage of an abnormal range is applied to the busbar 215 using 136 or the like, the relay 136 may be turned on to limit the range of the voltage input to the sensing IC 120. As a result, the sensing IC 120 can be protected from the overvoltage / reverse voltage of the busbar 215.

FIG. 3 is a diagram illustrating an output waveform of the logic circuit NAND 135 illustrated in FIG. 2. When the voltage across the bus bar 215 is in the forward direction, the overvoltage may be measured through the first voltage meter U1 131. When the voltage across the bus bar 215 is in the reverse direction, the reverse voltage may be measured by the second voltage meter U2 132. For example, when the voltage at both ends is 3V, 3V may be output through the first voltage meter U1 131, and when the voltage at both ends is −1V, 1V may be output through the second voltage meter U2 132.

In consideration of the sensing IC input voltage range, the reference value of the comparator 133/134 should be set. The upper limit value for the forward voltage may be set to the first reference value VHI of the first comparator U3 133, and the lower limit value for the reverse voltage may be set to the second reference value VLO of the second comparator U4 134. have. That is, the output of the logic circuit NAND 136 may be activated for a voltage outside the sensing IC input voltage. As the relay 136 is turned on, the bus bar 215 and the relay 136 may be in parallel, thereby lowering the combined resistance value. The voltage across the busbar 215 can be lowered within the normal range. As a result, the sensing IC 130 may be prevented from being burned out due to the overvoltage / reverse voltage.

4 is a diagram illustrating a method of protecting a sensing IC from busbar overvoltage / reverse voltage of the battery management system 100 according to an exemplary embodiment of the present disclosure. 1 to 4, an operation method of the battery management system 100 may proceed as follows.

An ignition (IG) switch of the vehicle may be turned on (S110). The battery management system BMS may be turned on (S120). The voltage across both ends of the busbar 215 may be measured through the voltage measuring devices U1 and U2 (see FIG. 2) (S130). It may be determined whether the measured voltage at both ends is outside the normal range (S140). If the voltage at both ends of the busbar 215 is outside the normal range, that is, the voltage at both ends of the busbar 215 is greater than or equal to the upper limit value VHI of the input voltage, or the voltage at both ends of the busbar 215 is equal to or greater than the input voltage. When lower than or equal to the lower limit value VLO, the bus bar 215 may be determined to be in an overvoltage / reverse voltage state. In this case, the voltage protection circuit 130 may perform a protection circuit operation. Here, the protection circuit operation 130 may include driving of the relay 136 (S150).

The steps and / or actions according to the invention may occur simultaneously in different embodiments in different order, in parallel, or for other epochs, etc., as would be understood by one of ordinary skill in the art. Can be.

In some embodiments, some or all of the steps and / or actions may be directed to instructions, programs, interactive data structures, clients, and / or servers stored on one or more non-transitory computer-readable media. At least some may be implemented or performed using one or more processors. One or more non-transitory computer-readable media may be illustratively software, firmware, hardware, and / or any combination thereof. In addition, the functionality of the "module" discussed herein may be implemented in software, firmware, hardware, and / or any combination thereof.

One or more non-transitory computer-readable media and / or means for implementing / performing one or more operations / steps / modules of embodiments of the present invention may be used in application-specific integrated circuits (ASICs), standard integrated circuits, A controller that performs appropriate instructions, including a microcontroller, and / or an embedded controller, field-programmable gate arrays (FPGAs), complex programmable logic devices (CPLDs), and the like. Does not.

Meanwhile, the voltage protection circuit 130 shown in FIG. 1 is disposed outside the sensing IC 120. However, the present invention is not necessarily limited thereto. The voltage protection circuit of the present invention may be disposed inside the sensing IC.

5 is a diagram illustrating a battery management system 1000 according to another exemplary embodiment of the present disclosure. Referring to FIG. 5, the battery management system 1000 may include a plurality of sensing ICs 1110, 1120, and 1130 and a BMC controller 1200.

Each of the sensing ICs 1110, 1120, and 1130 may be implemented to monitor a voltage of at least two battery cells connected in series of the battery pack. In an embodiment, each of the sensing ICs 1110, 1120, and 1130 may generate a failure signal according to a monitoring result. Meanwhile, although the number of sensing ICs shown in FIG. 3 is 3, it should be understood that the present invention is not limited thereto.

In an embodiment, the sensing ICs 1110, 1120, and 1130 may be connected to each other in a daisy-chain manner. Each of the sensing ICs 1110, 1120, and 1130 may be implemented to generate a failure signal when the voltage of the battery cell is greater than or equal to a predetermined value.

In some example embodiments, each of the sensing ICs 1110, 1120, and 1130 may include voltage protection circuits 1112, 1122, and 1132 to protect the inside of the sensing IC from an overvoltage / reverse voltage of a bus bar. Each of the voltage protection circuits 1112, 1122, and 1132 may be implemented in the same manner as the voltage protection circuit 130 shown in FIG. 2.

The BMS controller 1200 may be implemented to control the overall operation of the battery management system 1000. The BMS controller 1200 may receive a failure signal from the sensing ICs 1110, 1120, and 1130 and determine whether to connect a battery charging voltage to the battery pack.

The microcomputer 1220 may be implemented to control the overall operation of the microcomputer BMS 1000. In an embodiment, the microcomputer 1220 may include a microcontroller (MCU).

The input pin of the IC that senses the voltage across the bus-bar generally has a limited voltage range, and if more than a limited voltage is applied to the IC input terminal, the IC may be burned out. In the case of normal BUS-BAR connection, the resistance value is low, so the voltage range is within the input voltage range of the sensing IC.However, in the event of a failure such as a poor BUS-BAR connection or disconnection, the voltage exceeding the sensing IC input voltage range is the sensing IC. It is applied to the input terminal, which causes the sensing IC to burn out. In case of abnormal wiring of BUS-BAR, using voltage measuring device, comparator, relay, etc. to protect sensing IC, when the voltage of abnormal range is applied, relay is turned on to limit the range of voltage input to sensing IC. Protect the IC

On the other hand, the content of the present invention described above is only specific embodiments for carrying out the invention. The invention will include not only specific and practically available means per se, but also technical ideas as abstract and conceptual ideas that may be utilized in future technology.

100: battery management system
110, 120: sensing IC
130: voltage protection circuit
131, 132: voltage detector
133, 134: comparator
135: logic circuit
136: relay

Claims (14)

A sensing integrated circuit for monitoring a voltage of each of the battery cells connected to the busbar; And
Positioned in parallel between the busbar and the sensing integrated circuit to measure the voltage across the busbar, determine whether the measured voltage is within an input voltage range, and wherein the measured voltage is greater than or equal to a first reference value And a voltage protection circuit for changing the measured voltage to a voltage within the input voltage range when the reference value is less than the reference value, and outputting the voltage to the input pins of the sensing integrated circuit. The method of claim 1,
And the voltage protection circuit outputs the measured voltage to the input pins when the measured voltage is within the input voltage range. The method of claim 1,
And the voltage protection circuit turns on a relay connected in parallel to the busbar to change the measured voltage to a voltage within the input voltage range. The method of claim 3, wherein
And turning on the relay, a parallel resistor is coupled to the busbar so that the measured voltage is lowered to a voltage within the input voltage range. The method of claim 3, wherein
The voltage protection circuit,
A first voltage meter for measuring a voltage across the busbar;
A second voltage meter for measuring a voltage across the busbar;
A first comparator for comparing an output value of the first voltage meter and a first reference value;
A second comparator for comparing an output value of the second voltage meter and a second reference value; And
A logic circuit for logically calculating an output value of the first comparator and an output value of the first comparator,
And the relay is turned on in accordance with an output value of the logic circuit. The method of claim 5,
The first comparator includes a positive input terminal for receiving the first reference value and a negative input terminal for receiving an output value of the first voltage meter.
The second comparator includes a positive input terminal for receiving an output value of the second voltage meter and a negative input terminal for receiving the second reference value. The method of claim 6,
The first reference value is a reference value for determining the overvoltage,
And the second reference value is a reference value for determining a reverse voltage. The method of claim 5,
And the relay is turned on according to a result of the logic circuit to connect between input pins of the sensing integrated circuit. The method of claim 5,
And the logic circuit performs a NAND operation. In the operation method of the battery management system:
Measuring a voltage across the bus bar by placing the bus bar in parallel between the sensing integrated circuit;
Determining whether the measured voltage is out of the normal range; And
When the measured voltage is greater than or equal to the first reference value or less than or equal to the second reference value, the measured voltage is changed to a voltage within the normal range and output to the input pins of the sensing integrated circuit to perform a circuit protection operation for the sensing integrated circuit. A method comprising performing. The method of claim 10,
Determining whether it is out of the normal range,
Determining whether the measured voltage is greater than or equal to the first reference value; And
Determining whether the measured voltage is less than or equal to the second reference value. The method of claim 10,
Performing the circuit protection operation,
Turning on a relay connected in parallel to the busbar to lower the measured voltage to a voltage within the normal range. The method of claim 10,
If the measured voltage is within the normal range, outputting the measured voltage to input pins of the sensing integrated circuit. The method of claim 10,
And measuring the voltage across the busbar when the measured voltage does not deviate from the normal range.

Images