KR20180052320A - Apparatus and method for detecting disconnection of wire in battery management system - Google Patents

Abstract

The present invention relates to a disconnection detecting apparatus for a battery management system, and a disconnection detecting apparatus of a battery management system according to an embodiment of the present invention includes a balancing resistor, a current source, and a switch serially connected through a balancing line, A balancing circuit for performing the balancing operation; A sensing unit for sensing a voltage through a sensing line including a sensing resistor; And a controller for controlling on / off of the switch included in the balancing circuit, receiving a balancing voltage sensed by the sensing unit in a state where the switch is turned on, determining whether the line is disconnected through the balancing voltage input from the sensing unit Wherein the balancing line, the sensing line, or one end thereof is connected to the positive electrode or the negative electrode of the battery through the balancing voltage input from the sensing unit when the line disconnection is detected, And detecting the position of the disconnection line among the common lines connected to the common contact of the sensing line and the balancing line.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a battery management system,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery management system that can be used in an apparatus using electric energy, and more particularly, to an apparatus and method for detecting a disconnection of a line included in a battery management system.

In recent years, various devices such as industrial devices, home appliances and automobiles using high-voltage batteries have appeared, and especially in the field of automobile technology, the use of high-voltage batteries is becoming more active.

Automobiles that use internal combustion engines that use fossil fuels such as gasoline or heavy oil as the main fuel have a serious impact on pollution such as air pollution. Therefore, in recent years, efforts have been made to develop an electric vehicle or a hybrid vehicle in order to reduce pollution.

Electric vehicles (EVs) are vehicles that do not use petroleum fuels and engines but that use electric batteries and electric motors. That is, an electric vehicle that drives an automobile by rotating an electric motor that is accumulated in a battery is developed prior to a gasoline automobile, but is not commercialized because of problems such as a heavy weight of the battery, a limitation of the capacity of the battery, And environmental problems became serious, research for commercialization began in the 1990s.

On the other hand, hybrid technology (HEV) that uses electric vehicles, fossil fuels and electric energy adaptively is being commercialized as battery technology has been developed remarkably. Since HEV uses gasoline and electricity together as a power source, it is evaluated positively in terms of fuel efficiency improvement and exhaust gas reduction, and it is expected to play an intermediate role in evolving into a fully electric vehicle.

Since HEV and EV vehicles using such electric energy use a battery in which a plurality of rechargeable secondary cells are packed as a main power source, there is no exhaust gas and noise is small. have.

Since the performance of a battery using the electric energy directly affects the performance of the vehicle, it is necessary to measure the voltage of each battery cell, the voltage and current of the entire battery, and to efficiently manage charge and discharge of each battery cell However, a battery management system (BMS) is required to monitor the state of a cell sensing IC that senses each battery cell, thereby enabling stable control of the corresponding cell.

Meanwhile, when the line connecting the respective components of the battery management system is disconnected, a charging current flowing into the battery may be introduced into the battery controller. Therefore, there is a need to diagnose disconnection of the line. However, in the conventional art, only the presence or absence of disconnection of the line is detected, and the disconnection position can not be accurately detected.

Korean Patent Laid-Open Publication No. 10-2012-0059943

It is an object of the present invention to detect not only the presence or absence of disconnection of a line connected to a battery cell but also the position of a disconnection line in a line connected to the battery cell.

A single line detecting apparatus of a battery management system according to an embodiment of the present invention includes a balancing circuit that includes a balancing resistor, a current source, and a switch serially connected through a balancing line to perform voltage balancing of the battery; A sensing unit for sensing a voltage through a sensing line including a sensing resistor; And a controller for controlling on / off of the switch included in the balancing circuit, receiving a balancing voltage sensed by the sensing unit in a state where the switch is turned on, determining whether the line is disconnected through the balancing voltage input from the sensing unit Wherein the balancing line, the sensing line, or one end thereof is connected to the positive electrode or the negative electrode of the battery through the balancing voltage input from the sensing unit when the line disconnection is detected, And detecting the position of the disconnection line among the common lines connected to the common contact of the sensing line and the balancing line.

In one embodiment, the controller compares the balancing voltage with a normal range voltage to detect whether the line is disconnected.

In one embodiment, the control unit detects the position of the disconnected line among the balancing line, the sensing line, or the common line when the balancing voltage deviates from the normal range voltage.

In one embodiment, the control unit detects that the balancing line is disconnected when the balancing voltage is equal to the voltage of the battery sensed by the sensing unit.

In one embodiment, the control unit detects that the sensing line is disconnected when the balancing voltage has a full-scale value.

In one embodiment, the control unit detects that the common line is disconnected when the balancing voltage has a zero-scale value.

A method for diagnosing a single line in a battery management system according to an embodiment of the present invention includes a balancing circuit including a balancing resistor, a current source, and a switch connected in series through a balancing line to perform voltage balancing of the battery and a sensing line including a sensing resistor And a sensing unit for sensing a voltage through the switch, the method comprising: an ON step of turning on the switch; An input step of receiving a balancing voltage sensed while the switch is turned on; Detecting whether a line is disconnected through the balancing voltage input in the input step; And when the line disconnection is detected in the disconnection detection step, the balancing line, the sensing line, or one end is connected to the positive electrode or the negative electrode of the battery through the balancing voltage inputted in the input step, and the other end is connected to the balancing line And a disconnection position detecting step of detecting the disconnection of the disconnection line among the common lines connected to the common contact of the sensing line.

In one embodiment, the disconnection detecting step detects the disconnection of the line by comparing the balancing voltage with a normal range voltage.

In one embodiment, the disconnection detecting step detects line disconnection when the balancing voltage deviates from the normal range voltage.

In one embodiment, the disconnection position detecting step detects that the balancing line is disconnected when the balancing voltage is equal to the voltage of the battery.

In one embodiment, the disconnection position detecting step detects that the sensing line is disconnected when the balancing voltage has a full-scale value.

In one embodiment, the disconnection position detecting step detects that the common line is disconnected when the balancing voltage has a zero-scale value.

The present invention measures the balancing voltage across the balancing circuit to detect the presence or absence of a line connected to the battery cell.

Thus, there is an effect that the position of the line where the disconnection occurred in the line connected to the battery cell can be detected.

Therefore, the accuracy of disconnection detection is improved and the stability of the battery management system is improved.

FIG. 1 is a configuration diagram of a single line diagnostic apparatus of a battery management system according to an embodiment of the present invention.
2 is a diagram illustrating a process of measuring a balancing voltage in a battery management system according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating a disconnection position of a line detected in a single line device of a battery management system according to an embodiment of the present invention. FIG.
4 is a diagram showing a sensing voltage according to a disconnection state of a line.
FIG. 5 is a flowchart sequentially illustrating a method of diagnosing a wire breakage of a breakage diagnostic apparatus of a battery management system according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In describing the embodiments, descriptions of techniques which are well known in the technical field to which the present invention belongs and which are not directly related to the present invention are not described. This is for the sake of clarity of the present invention without omitting the unnecessary explanation.

For the same reason, some of the components in the drawings are exaggerated, omitted, or schematically illustrated. Also, the size of each component does not entirely reflect the actual size. In the drawings, the same or corresponding components are denoted by the same reference numerals.

Hereinafter, a single line diagnostic apparatus of a battery management system according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG.

FIG. 1 is a configuration diagram of a single line diagnostic apparatus of a battery management system according to an embodiment of the present invention.

Referring to FIG. 1, an apparatus for diagnosing a breakdown of a battery management system according to an embodiment of the present invention includes a balancing circuit, a sensing unit 10, and a control unit 20.

In FIG. 1, four batteries are connected in series. However, the battery may refer to one battery cell, and is not limited to the number of battery cells shown in FIG. Also, the battery may refer to a battery module including a plurality of battery cells, and may refer to a plurality of battery modules having a plurality of battery modules.

The balancing circuit performs voltage balancing of the batteries (VC1, VC2, VC3, VC4). The sensing unit 10 senses a voltage. The control unit 20 detects whether or not the line is disconnected.

Hereinafter, each configuration of the breakage diagnosis apparatus of the battery management system according to an embodiment of the present invention will be described in detail.

The balancing circuit includes balancing resistors Rb1, Rb2, Rb3 and Rb4, current sources CS1, CS2, CS3 and CS4 and switches SW1, SW2, SW3 and SW4. At this time, the balancing resistors Rb1, Rb2, Rb3 and Rb4, the current sources CS1, CS2, CS3 and CS4 and the switches SW1, SW2, SW3 and SW4 are connected through balancing lines L11, L21, L31 and L41 And are connected in series with each other. The switches SW1, SW2, SW3 and SW4 are switches for forcing a specific current value of the current sources CS1, CS2, CS3 and CS4 to flow to the balancing lines L11, L21, L31 and L41 at the time of turning on.

In this case, the values of the current sources CS1, CS2, CS3 and CS4 are set to be larger than the values of the current sources included in the general balancing circuit. For example, the values of the current sources CS1, CS2, CS3, and CS4 can be set to have values from 10 mA to 20 mA. Thus, even if the currents of the current sources CS1, CS2, CS3, and CS4 flow into the sensing resistors Rf0, Rf1, Rf2, Rf3, and Rf4 having a very small resistance value as described later, A voltage drop of a magnitude that is not negligible compared to the voltage of VC4 occurs.

The balancing circuit may further include a plurality of balancing switches (not shown) connected in parallel to the series-connected current sources CS1, CS2, CS3, CS4 and the switches SW1, SW2, SW3, SW4, respectively, . Specifically, the balancing circuit turns on a balancing switch connected to an overcharged battery among the plurality of balancing switches, so that a current of the overcharged battery flows through a line connected to the overcharged battery among the balancing lines L11, L21, L31 and L41 . Accordingly, power consumption occurs through the balancing resistors Rb1, Rb2, Rb3, and Rb4 through balancing resistors connected to the overcharged battery. Accordingly, the voltage of the overcharged battery is discharged, and the voltages of the batteries VC1, VC2, VC3, and VC4 are balanced.

Hereinafter, for convenience of explanation, the first balancing circuit includes a first balancing resistor Rb1, a first current source CS1, and a first switch SW1 connected in series through a first balancing line L11 define. Also, the second balancing circuit is defined to include a second balancing resistor Rb2, a second current source CS2, and a second switch SW2 connected in series through a second balancing line L21.

Also, the third balancing circuit is defined as including a third balancing resistor Rb3, a third current source CS3 and a third switch SW3 connected in series via a third balancing line L31. The fourth balancing circuit is defined to include a fourth balancing resistor Rb4, a fourth current source CS4 and a fourth switch SW4 connected in series through a fourth balancing line L41.

The sensing unit 10 senses the voltage by flowing a sensing current to the sensing lines L0, L12, L22, L32 and L42 including the sensing resistors Rf0, Rf1, Rf2, Rf3 and Rf4. The sensing unit 10 senses the voltage across the batteries VC1, VC2, VC3, and VC4 or senses the balancing voltage across the balancing circuit.

Specifically, when the switches SW1, SW2, SW3, and SW4 are turned off, the voltage across the batteries VC1, VC2, VC3, and VC4 is sensed in the sensing unit 10. [ For example, if the third sensing resistor Rf3, the third battery cell VC3, and the second sensing resistor Rf2 are connected in a state where the third switch SW3 is off in the sensing unit 10, When sensing is performed by flowing a sensing current, the voltage across the third battery cell (VC3) is sensed in the sensing unit (10).

Since the resistance value of the second sensing resistor Rf2 and the third sensing resistor Rf3 and the sensing current are very small values, the sensing current is applied to the second sensing resistor Rf2 and the third sensing resistor Rf3 The voltage drop occurring in the second sensing resistor Rf2 and the third sensing resistor Rf3 can be neglected.

On the other hand, when the switches SW1, SW2, SW3, and SW4 are turned on, the sensing unit 10 senses the voltage across the balancing circuit at the sensing unit 10. For example, in the sensing unit 10, when the third switch SW3 is turned on, the third sensing resistor Rf3, the third battery cell VC3, and the second sensing resistor Rf2, When the current is sensed by flowing, the sensing unit 10 senses the balancing voltage across the third balancing circuit.

This is because the resistance values of the second sensing resistor Rf2 and the third sensing resistor Rf3 are very small values but the current value of the third current source CS3 is much larger than the sensing current and the third current source CS3 flows in the second sensing resistor Rf2, the voltage drop occurring in the second sensing resistor Rf2 can not be ignored.

2 is a diagram illustrating a process of measuring a balancing voltage in a battery management system according to an embodiment of the present invention.

Referring to FIG. 2, a process of voltage sensing in the sensing unit 10 in a state where the third switch SW3 is turned on can be confirmed. That is, when the sensing unit 10 senses the voltage in the state that the third switch SW3 is turned on, the current of the third current source CS3 flows through the third balancing circuit, the second sensing resistor Rf2, Flows to the path connecting the battery cell VC3, and the sensing unit 10 senses the balancing voltage across the third balancing circuit. When the balancing voltage across the third balancing circuit is Vb3 and the current value of the third current source CS3 is in the range of CS3_min to CS3_max, VCELL3 - Rf2 x CS3_max <Vb3 <VCELL3 - Rf2 x CS3_min do.

The control unit 20 controls ON / OFF of the switches SW1, SW2, SW3, and SW4 included in the balancing circuit.

The control unit 20 receives the balancing voltage from the sensing unit 10 and detects whether the line is disconnected through the balancing voltage. Specifically, the control unit 20 compares the balancing voltage with a normal range voltage to detect whether the line is disconnected. At this time, when the balancing voltage deviates from the normal range voltage, the control unit 20 detects a line disconnection.

For example, when detecting the disconnection of a line connected to the third battery cell VC3, the control unit 20 sets the balancing voltage across the third balancing circuit as Vb3 and the current value of the third current source CS3 If Vb3 has a value in the range of CS3_min to CS3_max, it is determined that there is no line break when VCELL3 - Rf2 x CS3_max <Vb3 <VCELL3 - Rf2 x CS3_min. However, when Vb3 is not VCELL3 - Rf2 x CS3_max < Vb3 < VCELL3 - Rf2 x CS3_min, the line disconnection is detected.

FIG. 3 is a diagram illustrating a disconnection position of a line detected in a single line device of a battery management system according to an embodiment of the present invention. FIG.

Referring to FIG. 3, when the line connected to the third battery cell VC3 is disconnected, the disconnection position can be confirmed. That is, even if the line connected to the third battery cell VC3 is detected to be disconnected, it is determined whether the third balancing line L31 is disconnected (①), the third sensing line L32 is disconnected (②) , And whether or not the third common line L33 is disconnected (3).

When the line break is detected, the control unit 20 detects the position of the broken line. The control unit 20 controls the balancing voltages L11, L21, L31 and L41 and the sensing lines L0, L12, L22, L32 and L42 or the common lines L13, L23, L33 and L43, The position of the line is detected. The other ends of the common lines L13, L23, L33 and L43 are connected to the balancing lines L11, L21, L31 and L41, (L0, L12, L22, L32, L42).

Specifically, when the balancing voltage is equal to the voltages of the batteries VC1, VC2, VC3, and VC4 sensed by the sensing unit 10, the control unit 20 disconnects the balancing lines L11, L21, L31, . For example, when the third balancing line L31 is disconnected, the voltage of the third battery cell VC3 is sensed in the sensing unit 10 by turning on the third switch SW3. This is because, when the third balancing line L31 is disconnected, the third switch SW3 is turned off.

On the other hand, when the balancing voltage has a full-scale value, the control unit 20 detects that the sensing lines L0, L12, L22, L32, and L42 are disconnected. At this time, the full-scale value may mean a voltage value of 5V. For example, when the third sensing line L32 is disconnected, the third sensing line L32 is floating, and the fourth diode Z4 is connected. In the sensing unit 10, full-scale values are sensed.

On the other hand, when the balancing voltage has a zero-scale value, the control unit 20 detects that the common lines L13, L23, L33, and L43 are disconnected. At this time, the zero-scale value may mean a voltage value of 0V. For example, when the third common line L33 is disconnected, the voltage charged in the third capacitor C3 is discharged when the third switch SW3 is turned on. Therefore, in the sensing unit 10, the zero- scale value is sensed.

4 is a diagram showing a sensing voltage according to a disconnection state of a line.

Referring to FIG. 4, the sensing voltage value according to the disconnection state of a line connected to the third battery cell VC3 can be confirmed. That is, when the line connected to the third battery cell VC3 is not disconnected, it can be confirmed that the sensing voltage value is in the normal range (VCELL3 - Rf2 x CS3_max - VCELL3 - Rf2 x CS3_min).

But. When the third balancing line L31 is disconnected, it can be confirmed that the sensing voltage value is equal to the voltage value Vcell3 of the third battery cell VC3. In addition, when the third sensing line L32 is disconnected, it can be confirmed that the sensing voltage value has a full-scale value. In addition, when the third common line L33 is disconnected, it can be confirmed that the sensing voltage value has a zero-scale value.

Hereinafter, a method for diagnosing a wire breakage of the battery management system according to an embodiment of the present invention will be described with reference to FIG. Here, the description of the parts overlapping with those described with reference to Figs. 1 to 4 will be omitted.

FIG. 5 is a flowchart sequentially illustrating a method of diagnosing a wire breakage of a breakage diagnostic apparatus of a battery management system according to an embodiment of the present invention.

Referring to FIG. 5, first, the control unit 20 turns on the switches SW1, SW2, SW3, and SW4 (S101). Specifically, the control unit 20 turns on only the switches among the switches SW1, SW2, SW3, and SW4 connected to the battery cells to detect whether the line is disconnected. For example, when the controller 20 detects a disconnection of a line connected to the third battery cell VC3, the controller 20 turns on only the third switch SW3.

Thereafter, the control unit 20 receives the balancing voltage sensed while the switches SW1, SW2, SW3, and SW4 are turned on in the sensing unit 10 (S103). Specifically, the control unit 20 receives the balancing voltage sensed in the ON state of the switches SW1, SW2, SW3, and SW4 that are connected to the battery cells to detect whether the line is disconnected. For example, the control unit 20 can receive the balancing voltage sensed in the sensing unit 10 while the third switch SW3 is turned on.

Thereafter, the controller 20 compares the sensed balancing voltage with the normal range voltage in step S103 (S105).

If the balancing voltage sensed at step S103 is greater than the normal range voltage at step S105, the control unit 20 detects a line disconnection at step S107.

Then, the control unit 20 determines whether the balancing voltage sensed in step S103 is equal to the voltages of the batteries VC1, VC2, VC3, and VC4 (S109).

If the balancing voltage sensed in step S103 is equal to the voltages of the batteries VC1, VC2, VC3, and VC4, the control unit 20 determines that the balancing lines L11, L21, L31, and L41 are disconnected (S111).

Alternatively, the controller 20 determines whether the balancing voltage sensed in step S103 has a full-scale value (step S113).

If the balancing voltage sensed in step S103 has a full-scale value, the controller 20 determines that the sensing lines L12, L22, L32, and L42 are disconnected (step S113) S115).

Alternatively, the controller 20 determines whether the balancing voltage sensed in step S103 has a zero-scale value (S117).

If the balancing voltage sensed in step S103 has a zero-scale value, the controller 20 determines that the common lines L13, L23, L33, and L43 are disconnected (step S117) S119).

It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all changes or modifications derived from the meaning and scope of the claims and the equivalents thereof are included in the scope of the present specification Should be interpreted.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is not intended to limit the scope. It is to be understood by those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

10: sensing unit
20:
VC1, VC2, VC3, VC4: Battery
Rb1, Rb2, Rb3, Rb4: balancing resistance
SW1, SW2, SW3, SW4: switch
CS1, CS2, CS3, CS4: current sources
L11, L21, L31, L41: balancing line
Rf0, Rf1, Rf2, Rf3, Rf4: sensing resistance
L0, L12, L22, L32, L42: sensing line
L13, L23, L33, L43: common line
C1, C2, C3, C4: Capacitors
Z1, Z2, Z3, Z4: Diodes

Claims (12)

A balancing circuit for balancing the voltage of the battery including a balancing resistor, a current source and a switch serially connected through a balancing line;
A sensing unit sensing a voltage through a sensing line including a sensing resistor; And
A control unit for controlling on / off of the switch included in the balancing circuit, receiving a balancing voltage sensed by the sensing unit in a state where the switch is turned on, and determining whether the line is disconnected through the balancing voltage input from the sensing unit And a control unit for detecting the position,
Wherein the balancing line, the sensing line, or one end thereof is connected to the positive electrode or the negative electrode of the battery through the balancing voltage input from the sensing unit when the line disconnection is detected, and the other end is connected to the balancing line, And the position of the disconnected line among the common lines connected to the common contacts of the battery management system is detected. The method according to claim 1,
Wherein the control unit compares the balancing voltage with a normal range voltage to detect whether the line is disconnected. 3. The method of claim 2,
Wherein the control unit detects the position of the disconnected line among the balancing line, the sensing line, or the common line when the balancing voltage is out of the normal range voltage. The method of claim 3,
Wherein the control unit detects that the balancing line is disconnected when the balancing voltage is equal to the voltage of the battery sensed by the sensing unit. The method of claim 3,
Wherein the controller detects that the sensing line is disconnected when the balancing voltage has a full-scale value. The method of claim 3,
Wherein the control unit detects that the common line is disconnected when the balancing voltage has a zero-scale value. A balancing circuit for balancing the voltage of the battery including a balancing resistor, a current source, and a switch connected in series via a balancing line, and a sensing unit for sensing a voltage through a sensing line including a sensing resistor. In this case,
Turning on the switch;
An input step of receiving a balancing voltage sensed while the switch is turned on;
Detecting whether a line is disconnected through the balancing voltage input in the input step;
Wherein when the line disconnection is detected in the disconnection detection step, the balancing line, the sensing line, or one end is connected to the positive electrode or the negative electrode of the battery through the balancing voltage inputted in the input step, and the other end is connected to the balancing line, And a disconnection position detecting step of detecting disconnection of a line among the common lines connected to the common contacts of the sensing line. 8. The method of claim 7,
Wherein the step of detecting whether the line is disconnected is performed by comparing the balancing voltage with a normal range voltage to detect whether the line is disconnected. 9. The method of claim 8,
Wherein the disconnection detecting step detects a line disconnection when the balancing voltage deviates from the normal range voltage. 10. The method of claim 9,
Wherein the disconnection position detecting step detects that the balancing line is disconnected when the balancing voltage is equal to the voltage of the battery. 10. The method of claim 9,
Wherein the disconnection position detecting step detects that the sensing line is disconnected when the balancing voltage has a full-scale value. 10. The method of claim 9,
Wherein the disconnection position detecting step detects that the common line is disconnected when the balancing voltage has a zero-scale value.

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