KR101846200B1 - Apparatus and method for detecting wire disconnection in battery management system - Google Patents

Abstract

The present invention relates to an apparatus for detecting wire disconnection of a battery management system. According to an embodiment of the present invention, the apparatus for detecting wire disconnection of a battery management system, which manages a battery comprising a plurality of serially connected battery cells comprises: a voltage increase unit which is connected to one end portion of the battery, receives voltage of the battery, increases the voltage of the battery by a predetermined voltage, and outputs the increased voltage; a plurality of switches which individually connect a plurality of wires, individually connected to both end portions of the battery cells, to the voltage increase unit; and a control unit which senses voltage of each battery cell by controlling on/off states of the switches, compares sensed voltage of each battery cell to voltage in a normal range, and detects disconnection of the wires. When one of the wires is disconnected, the voltage of one end portion of the battery cell connected to the disconnected wire is output voltage of the voltage increase unit wherein the disconnected wire is sensed by the control unit.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an apparatus and a method for detecting disconnection of a battery management system,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a battery management system that can be used in an apparatus using electrical energy, and more particularly, to an apparatus and method for detecting wire disconnection of battery cells.

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.

If a wire connecting the battery cells is disconnected and opened, a charging current flowing into the battery may be introduced into the battery controller. Therefore, it is necessary to diagnose whether the wire is open or not. The diagnosis of opening of the wire is generally performed by sensing the voltage across the battery cell. At this time, there may be a case where the voltage of the battery cell is diagnosed to be within the normal range due to the sensing error although the wire is opened. This is because the voltage of the battery cell has a relatively narrow voltage range of 0 to 5 V, and when the sensing error is large, the wire open diagnosis may become inaccurate.

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

An object of the present invention is to accurately detect wire openings connecting battery cells.

A single line detecting device of a battery management system for managing a battery including a plurality of battery cells connected in series, the device for detecting a single line of a battery management system according to an embodiment of the present invention includes: A voltage step-up unit for receiving and outputting the battery voltage by a predetermined voltage; A plurality of switches individually connecting a plurality of wires respectively connected to both ends of the plurality of battery cells to the voltage step-up unit; And a controller for controlling on / off of the plurality of switches to sense the voltage of each of the plurality of battery cells and to detect a disconnection of the plurality of wires by comparing a voltage of each of the plurality of sensed battery cells with a normal range voltage And a voltage at one end of the battery cell connected to the disconnected wire sensed by the control unit is an output voltage of the voltage step-up unit when there is a disconnected wire among the plurality of wires.

In one embodiment, the voltage step-up unit is a charge pump.

In one embodiment, a plurality of pull-up devices (not shown) are connected, one end of which is connected to the plurality of switches, and the plurality of wires are connected to the other end to prevent a voltage of the plurality of battery cells from floating. As shown in FIG.

In one embodiment, each of the plurality of pull-up elements is a current source that supplies a constant current.

In one embodiment, the controller detects a disconnection of the plurality of wires through a battery cell that deviates from the normal range voltage among the voltages of the plurality of sensed battery cells.

In one embodiment, when detecting a battery cell out of the normal range voltage among the voltages of the plurality of sensed battery cells, the controller detects that a wire connected to the battery cell among the plurality of wires is disconnected .

In one embodiment, the control unit may further include a warning unit for alerting the user when a disconnection of the plurality of wires is detected.

A method for detecting a disconnection in a battery management system according to an embodiment of the present invention includes a voltage step-up unit that receives a voltage of a battery including a plurality of battery cells connected in series and raises the battery voltage by a predetermined voltage, A plurality of pull-up elements for preventing a voltage of a cell from being floating; and a disconnection detection circuit for detecting disconnection of a plurality of wires respectively connected to both ends of the plurality of battery cells through a control unit, The method of claim 1, further comprising: an on / off control step of on / off controlling a plurality of switches individually connecting the plurality of wires to the voltage step-up unit; A voltage sensing step of sensing a voltage of each of the plurality of battery cells according to on / off states of the plurality of switches controlled in the on / off control step; A voltage comparing step of comparing a voltage of each of the plurality of battery cells sensed in the voltage sensing step with a normal range voltage; And a disconnection detection step of detecting a disconnection of the plurality of wires through a comparison result in the voltage comparison step. When there is a disconnection wire among the plurality of wires, the disconnected wire sensed in the voltage sensing step And a voltage of one end of the connected battery cell is an output voltage of the voltage step-up unit.

In one embodiment, the voltage step-up unit is a charge pump.

In one embodiment, the disconnection detecting step detects a disconnection of the plurality of wires through a battery cell that deviates from the normal range voltage among the voltages of the plurality of battery cells sensed in the voltage sensing step .

In one embodiment, the disconnection detecting step may include detecting a battery cell out of the normal range voltage among the voltages of the plurality of battery cells sensed in the voltage sensing step, And detecting that the wire is disconnected.

In one embodiment, the method may further include a warning step of warning the user when a disconnection of the plurality of wires is detected in the disconnection detecting step.

The present invention adds a voltage raising circuit at one end of the battery, senses the voltage of the battery cells, and detects the opening of the wires connecting the battery cells.

Accordingly, even when an error occurs in the voltage sensing of the battery cells, the opening of the wire can be accurately detected.

Therefore, it is possible to prevent burn-out of the battery controller, which is caused by current flow due to the opening of the wye.

1 is a configuration diagram of a single wire detecting apparatus of a battery management system according to an embodiment of the present invention.
2 is a diagram illustrating a method of measuring a voltage of a battery cell in a single wire detecting apparatus of a battery management system according to an embodiment of the present invention.
Fig. 3 is a view showing an example in which wires are disconnected.
4 is a view showing an example in which wires are disconnected.
5 is a flowchart sequentially illustrating a method of detecting a disconnection of a disconnection detecting apparatus in 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 wire detecting apparatus for a battery management system according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG.

1 is a configuration diagram of a single wire detecting apparatus of a battery management system according to an embodiment of the present invention.

Referring to FIG. 1, an apparatus for detecting disconnection in a battery management system according to an embodiment of the present invention includes a voltage boosting unit 20, a plurality of switches SW1, SW2, SW3, SW4, and SW5, , P2, P3, P4, and P5, a control unit 30, and a warning unit 40. [

At this time, the battery management system refers to a system for managing the battery 10 installed in the vehicle. The battery 10 includes a plurality of battery cells C1, C2, C3, C4 connected in series. At this time, the number of battery cells included in the battery 10 shown in FIG. 1 is exemplary. For the convenience of explanation, it is assumed that the number of battery cells is four in the following description.

On the other hand, a plurality of wires L1, L2, L3, L4 and L5 are connected to both ends of the plurality of battery cells C1, C2, C3 and C4. Specifically, the first wire L1 is connected to the negative terminal (-) of the first battery cell C1 and the positive terminal (+) of the first battery cell C1 and the negative terminal The third wire L3 is connected to the positive electrode (+) of the second battery cell C2 and the negative electrode (-) of the third battery cell C3, and the third wire The fourth wire L4 is connected to the positive electrode of the battery cell C3 and the negative electrode of the fourth battery cell C4 and the fourth wire L4 is connected to the positive electrode of the fourth battery cell C4. (L5) are connected.

That is, the disconnection detecting apparatus of the battery management system according to an embodiment of the present invention detects whether or not a plurality of wires L1, L2, L3, L4, and L5 are disconnected.

The voltage step-up unit 20 receives the voltage of the battery 10 and raises the voltage of the battery 10 by a predetermined voltage. The plurality of switches SW1, SW2, SW3, SW4, and SW5 connect the voltage step-up unit 20 and the plurality of wires L1, L2, L3, L4, and L5, respectively. The plurality of pull-up elements P1, P2, P3, P4, P5 prevent the voltages of the plurality of battery cells C1, C2, C3, C4 from floating. The control unit 30 senses the voltage of each of the plurality of battery cells C1, C2, C3 and C4 and detects the disconnection of the plurality of wires L1, L2, L3, L4 and L5. The warning unit (40) warns the user when a break is detected.

On the other hand, the diodes D1, D2, D3, and D4 prevent current from flowing between the plurality of battery cells C1, C2, C3, and C4. Therefore, when the voltage of each of the plurality of battery cells C1, C2, C3, and C4 is sensed by the control unit 30, the battery cell voltages other than the battery cells sensed are not sensed.

Hereinafter, each configuration of the single wire detecting apparatus of the battery management system according to the embodiment of the present invention will be described in detail.

The voltage boosting unit 20 is connected to one end of the battery 10 and receives the voltage of the battery 10 to increase the voltage of the battery 10 by a predetermined voltage. Specifically, the voltage step-up unit 20 is connected to the positive electrode (+) of the fourth battery cell C4 among the plurality of battery cells C1, C2, C3, and C4 included in the battery 10. Therefore, the voltage step-up unit 20 receives a voltage obtained by summing the voltages of the plurality of battery cells C1, C2, C3 and C4, and outputs the voltage by raising the voltage by a predetermined voltage.

For example, when the voltage of each of the plurality of battery cells C1, C2, C3, and C4 is 4 V and the predetermined voltage is 10 V, the voltage step-up unit 20 generates a voltage of 4 x 4 = And outputs a voltage of 26 V by increasing the voltage by 10 V. At this time, the predetermined voltage varies depending on the configuration of the voltage step-

The voltage boosting unit 20 may mean a charge pump. The charge pump means a kind of DC to DC converter which uses a capacitor to produce an output of a voltage higher than the input power.

The plurality of switches SW1, SW2, SW3, SW4, and SW5 connect the voltage step-up unit 20 and the plurality of wires L1, L2, L3, L4, and L5, respectively. Specifically, when the first switch SW1 is turned on, the voltage boosting unit 20 is connected to the first wire L1, and when the second switch SW2 is turned on, The voltage boosting unit 20 and the third wire L3 are connected when the third switch SW3 is turned on and the fourth switch When the voltage step-up unit 20 and the fourth wire L4 are turned on and the fifth switch SW5 is turned on when the voltage step-up unit 20 and the fifth switch SW5 are turned on, Connect wire (L5).

The plurality of pull-up elements P1, P2, P3, P4 and P5 are connected between the plurality of switches SW1, SW2, SW3, SW4, SW5 and the plurality of wires L1, L2, L3, L4, C2, C3, and C4 of the battery cells C1, C2, C3, and C4 are prevented from floating.

Specifically, the first pull-up device P1 is connected between the first switch SW1 and the first wire L1, the second pull-up device P2 is connected between the second switch SW1 and the second wire L2, The third pull-up device P3 is connected between the third switch SW3 and the third wire L3 and the fourth pull-up device P4 is connected between the fourth switch SW4 and the fourth wire L4, and the fifth pull-up device P1 is connected between the fifth switch SW5 and the fifth wire L5.

Generally, in a battery management system, when a voltage of about 3 V to 5 V is measured by measuring a voltage of a battery cell, it is determined to be a logic high, and when a voltage of substantially 0 V is measured, it is determined to be a logic low. However, in an actual circuit, a cell voltage is not sensed by OV due to the influence of peripheral devices and capacitors, and a voltage including a noise value can be measured. In such a state, it is impossible to grasp the logical high or low state since the correct input value is not known. Such a state is generally referred to as a floating state, and when a floating state occurs, the system is unstable and it is impossible to measure an accurate circuit state. In order to solve the floating state, a pull-up or pull-down device can be used. In the present invention, a plurality of pull-up devices P1, P2, P3, P4, (C1, C2, C3, C4) from floating.

On the other hand, each of the plurality of pull-up elements P1, P2, P3, P4, and P5 may be a current source supplying a constant current.

The control unit 30 controls ON / OFF of the plurality of switches SW1, SW2, SW3, SW4, and SW5 to sense voltages of the plurality of battery cells C1, C2, C3, and C4. Specifically, when sensing the voltage of a specific battery cell among the plurality of battery cells C1, C2, C3, and C4, the controller 30 turns on only the switches connected to the wires connected to both ends of the battery cell to be sensed The back voltage is sensed.

Referring to FIG. 2, when the control unit 30 senses the voltage of the first battery cell C1, only the first switch SW1 and the second switch SW2 are turned on, And senses the voltage of the first battery cell C1 in the off state. At this time, the voltage sensed by the control unit 30 becomes a value obtained by subtracting the negative (-) voltage of the first battery cell C1 from the positive (+) voltage of the first battery cell C1.

If there is a disconnected wire among the plurality of wires L1, L2, L3, L4, and L5, the voltage at one end of the battery cell connected to the disconnected wire sensed by the control unit 30, Output voltage. This is because the voltage at one end of the battery cell connected to the disconnected wire becomes a voltage obtained by adding the voltage across the pull-up element to the output voltage of the voltage up unit 20. At this time, since the voltage across the pull-up element is close to 0 V, the voltage at one end of the battery cell connected to the disconnected wire becomes the output voltage of the voltage-

The control unit 30 compares the voltage of each of the plurality of sensed battery cells C1, C2, C3 and C4 with the normal range voltage to detect disconnection of the plurality of wires L1, L2, L3, L4 and L5. L2, L3, L4, and L5, respectively, through the battery cells that deviate from the normal range voltage among the voltages of the plurality of battery cells (C1, C2, C3, C4) sensed by the control unit 30. Specifically, ) Is detected. That is, the control unit 30 detects that the wire connected to the battery cell deviating from the normal range voltage is disconnected. The normal range voltage means a voltage ranging from 0 V to 5 V when the rated voltage of the plurality of battery cells (C1, C2, C3, C4) is 5V.

3, the third wire L3 is disconnected, and the voltages V1, V2, V3, and V4 of the plurality of battery cells C1, C2, C3, and C4 are all 4 V, The voltage V2 of the second battery cell C2 = 26 - 4 = 22 V when the output of the second battery cell 20 is V1 + V2 + V3 + V4 + 10 = 26V. In addition, the voltage V3 of the third battery cell C3 = 12-26 = -14V. However, since there is no disconnected wire other than the second wire L2, the voltage of the first battery cell C1 and the voltage of the fourth battery cell C4 become 4V.

Therefore, the control unit 30 determines that the voltage of the second battery cell C2 and the voltage of the third battery cell C3 are out of the normal range voltage, It is possible to detect that the connected third wire L3 is disconnected.

4, when the fourth wire L4 is disconnected and the voltages V1, V2, V3, and V4 of the plurality of battery cells C1, C2, C3, and C4 are all 4 V, and the diodes D1 The voltages of the first battery cell C1, the second battery cell C2 and the third battery cell C3 become 4 V when the voltage Vf across the terminals D2, D3, and D4 is 1 V. However, since the output of the voltage step-up unit 20 is changed to V1 + V2 + V3 - Vf + 10 = 21 V, the voltage V4 of the fourth battery cell C4 becomes 21 - 12 = 9 V.

Therefore, the control unit 30 can detect that the fourth wire L4 connected to the fourth battery cell C4 is disconnected because only the voltage of the fourth battery cell C4 is out of the normal range voltage.

The warning unit 40 alerts the user when the control unit 30 detects the disconnection of the plurality of wires L1, L2, L3, L4 and L5. For example, a warning message may be displayed on a video device such as an AVN (Audio Video Navigation) of a vehicle, or a warning sound may be emitted through audio equipment of a vehicle.

Hereinafter, a method of detecting a disconnection of a 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.

Referring to FIG. 5, first, the control unit 30 controls on / off of a plurality of switches SW1, SW2, SW3, SW4, and SW5 (S101).

The control unit 30 then sets the voltages of the plurality of battery cells C1, C2, C3, and C4 in accordance with the ON / OFF states of the plurality of switches SW1, SW2, SW3, SW4, (S103).

Then, the control unit 30 compares the voltage of each of the plurality of battery cells C1, C2, C3, and C4 sensed in step S103 with the normal range voltage (S105).

Then, the control unit 30 determines that the plurality of wires L1, L2, L3, and L4 are connected through the battery cells out of the normal range voltage among the voltages of the plurality of battery cells C1, C2, C3, , And L5 (S107). That is, the control unit 30 detects that the wire connected to the battery cell deviating from the normal range voltage is disconnected.

In step S109, the warning unit 40 alerts the user to the disconnection of the plurality of wires L1, L2, L3, L4, and L5.

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: Battery
20:
30:
40: Warning section

Claims (12)

A disconnection detecting apparatus for a battery management system for managing a battery including a plurality of battery cells connected in series,
A voltage step-up unit connected to one end of the battery for receiving the battery voltage and increasing the battery voltage by a predetermined voltage;
A plurality of switches individually connecting a plurality of wires respectively connected to both ends of the plurality of battery cells to the voltage step-up unit; And
A control unit for controlling on / off of the plurality of switches to sense the voltage of each of the plurality of battery cells, and detecting a disconnection of the plurality of wires by comparing a voltage of each of the plurality of sensed battery cells with a normal range voltage, Lt; / RTI >
Wherein the voltage of the one end of the battery cell connected to the disconnected wire sensed by the control unit is the output voltage of the voltage step-up unit when there is a disconnected wire among the plurality of wires. The method according to claim 1,
Wherein the voltage step-up unit is a charge pump. The method according to claim 1,
Further comprising a plurality of pull-up elements connected to one ends of the plurality of switches and connected to the plurality of wires to prevent voltage of the plurality of battery cells from floating, Disconnection detection device of system. The method of claim 3,
Wherein each of the plurality of pull-up elements is a current source that supplies a constant current. The method according to claim 1,
Wherein the control unit detects a disconnection of the plurality of wires through a battery cell that deviates from the normal range voltage among the voltages of the plurality of sensed battery cells. 6. The method of claim 5,
Wherein the controller detects that a wire connected to the battery cell among the plurality of wires is disconnected when a battery cell out of the normal range voltage among the voltages of the plurality of sensed battery cells is detected. Disconnection detection device of system. 7. The method according to any one of claims 1 to 6,
Further comprising a warning unit for warning the user when the control unit detects a disconnection of the plurality of wires. A voltage step-up unit that receives a voltage of a battery including a plurality of battery cells connected in series and raises the battery voltage by a predetermined voltage and outputs a plurality of pull-ups that prevent a voltage of the plurality of battery cells from being floating And detecting whether a plurality of wires respectively connected to both ends of the plurality of battery cells are disconnected through a pull-up device and a control unit, the method comprising:
An on / off control step of on / off controlling a plurality of switches individually connecting the plurality of wires to the voltage step-up unit;
A voltage sensing step of sensing a voltage of each of the plurality of battery cells according to on / off states of the plurality of switches controlled in the on / off control step;
A voltage comparing step of comparing a voltage of each of the plurality of battery cells sensed in the voltage sensing step with a normal range voltage; And
And a disconnection detecting step of detecting disconnection of the plurality of wires through a comparison result in the voltage comparing step,
Wherein the voltage at one end of the battery cell connected to the disconnected wire sensed in the voltage sensing step is the output voltage of the voltage step-up unit when there is a disconnected wire among the plurality of wires. 9. The method of claim 8,
Wherein the voltage step-up unit is a charge pump. 9. The method of claim 8,
Wherein the disconnection detecting step detects a disconnection of the plurality of wires through a battery cell that deviates from the normal range voltage among the voltages of the plurality of battery cells sensed in the voltage sensing step. Way. 11. The method of claim 10,
Wherein the disconnection detecting step detects that a wire connected to the battery cell among the plurality of wires is disconnected when detecting a battery cell which is out of the normal range voltage among the voltages of the plurality of battery cells sensed in the voltage sensing step And detecting a disconnection of the battery management system. The method according to any one of claims 8 to 11,
Further comprising a warning step of warning the user when a disconnection of the plurality of wires is detected in the disconnection detecting step.

Images