KR20200012417A - Apparatus and method for diagnosing abnormality of cell voltage sensing line - Google Patents

Abstract

The present invention relates to an apparatus for diagnosing an abnormality of a cell voltage sensing line by connecting a plurality of battery cells to a battery module connected in series through a cell voltage sensing line, and to a method for diagnosing an abnormality of a cell voltage sensing line using the apparatus. According to the present invention, an abnormality of a cell voltage sensing line is diagnosed using a cell balancing portion originally provided for voltage balancing of each battery cell, so that a separate additional configuration for diagnosing the abnormality of the cell voltage sensing line is not needed so as to be economical.

Description

Apparatus and method for diagnosing abnormalities in cell voltage sensing lines {APPARATUS AND METHOD FOR DIAGNOSING ABNORMALITY OF CELL VOLTAGE SENSING LINE}

The present invention relates to an apparatus for diagnosing an abnormality of a cell voltage sensing line connected to a battery module in which a plurality of battery cells are connected in series through a cell voltage sensing line, and a method of diagnosing abnormality of a cell voltage sensing line using the apparatus. will be.

In order to drive an electric vehicle or a hybrid vehicle, a large amount of power must be supplied to the driving motor. For this purpose, a plurality of battery modules in which a plurality of battery cells are connected in series are mounted in the electric vehicle or the hybrid vehicle. That is, dozens or hundreds of battery cells are mounted in an electric vehicle or a hybrid vehicle. In order to ensure stable charging and discharging of such battery cells, it is necessary to continuously monitor the cell voltage sensing lines connected to both ends of each battery cell. have.

The cell voltage sensing line senses the voltage of the battery cell and transmits the voltage to the battery management system (BMS), and the battery management system uses the voltage of the battery cell to charge a state of charge (SOC) of the battery cell. Manages the role.

However, if the resistance of the cell voltage sensing line becomes very small or large due to an abnormality in the cell voltage sensing line, it is impossible to accurately sense the voltage of the battery cell. Problems arise, which can quickly become a barrier to stable operation of electric and hybrid vehicles. Accordingly, there is a need for an apparatus and method for diagnosing an abnormality in a sense voltage sensing line so that an electric vehicle or a hybrid vehicle can operate stably.

Publication No. 2013-0044881 (published: 2013.05.03)

An object of the present invention is to provide an apparatus and method for diagnosing abnormality in a sense voltage sensing line, and furthermore, to provide an apparatus and method for shortening the diagnostic time and minimizing the impact on the life of components. The purpose is to.

In order to achieve the above object, the apparatus for diagnosing an abnormality of a cell voltage sensing line according to an embodiment of the present invention is connected to a battery module in which a plurality of battery cells are connected in series through a cell voltage sensing line to sense the cell voltage. An apparatus for diagnosing an abnormality of a line, comprising: a cell balancing unit comprising a switch and a switch resistor connected in series with each other and connected in parallel to each battery cell through the cell voltage sensing line; A voltage detector connected in parallel to the cell balancing unit; And controlling the operation of the switch, calculating a resistance value of the cell voltage sensing line using the voltage detected by the voltage detector according to the operation of the switch, and comparing the resistance value of the cell voltage sensing line to a reference resistance value. And an abnormality diagnosis unit for diagnosing the abnormality of the cell voltage sensing line.

The abnormality diagnosis unit may include a voltage detected when all of the switches are in an off state, a voltage detected when only the lowest switch among the switches is in an on state, and a case where only the switch at the highest level among the switches is in an on state. The resistance value of the cell voltage sensing line may be calculated by using the detected voltage and the voltage detected when only the odd-numbered switch is in the ON state based on the lowest switch.

Alternatively, the abnormality diagnosis unit may include a voltage detected when all of the switches are in an off state, a voltage detected when only the lowest switch among the switches is in an on state, and a case where only the switch at the highest level among the switches is in an on state. The resistance value of the cell voltage sensing line may be calculated using the detected voltage and the voltage detected when only the even switch is turned on based on the lowest switch.

The reference resistance value is a cell voltage calculated when the resistance value of the cell voltage sensing line calculated when the switch has the minimum allowable resistance value is set to a lower limit, and the cell voltage calculated when the switch has the maximum allowable resistance value. The resistance value of the sensing line may be set to an upper limit.

In addition, in order to achieve the above object, a method of diagnosing an abnormality of a cell voltage sensing line according to an embodiment of the present invention is a device that is connected to a battery module in which a plurality of battery cells are connected in series through the cell voltage sensing line. A cell balancing unit comprising a switch and a switch resistor connected in series with each other and connected in parallel to each battery cell through the cell voltage sensing line; A voltage detector detecting a voltage connected in parallel to the cell balancing unit; And an abnormality diagnosis unit configured to control an operation of the switch and diagnose an abnormality of the cell voltage sensing line using a voltage detected by the voltage detector according to the operation of the switch. A method for diagnosing an abnormality, the method comprising: calculating a resistance value of the cell voltage sensing line by using the voltage detected by the voltage detector by an error diagnosis unit according to an operation of the switch; And diagnosing an abnormality of the cell voltage sensing line by comparing the resistance value of the cell voltage sensing line with a reference resistance value.

The calculating of the resistance value of the cell voltage sensing line may include: a voltage detected when all of the switches are in an off state, a voltage detected when only the lowest switch among the switches is in an on state, and a highest value among the switches A resistance value of the cell voltage sensing line is calculated by using a voltage detected when only a switch in an on state and a voltage detected when only an odd number of switches are in an ON state based on the lowest switch. It is done.

Alternatively, the calculating of the resistance value of the cell voltage sensing line may include: a voltage detected when all of the switches are in an off state, a voltage detected when only a switch among the lowest of the switches is in an on state, and a highest value among the switches A resistance value of the cell voltage sensing line is calculated by using a voltage detected when only a switch in an on state and a voltage detected when only an even number of switches are in an on state based on the lowest switch. It is done.

The reference resistance value is a cell voltage calculated when the resistance value of the cell voltage sensing line calculated when the switch has the minimum allowable resistance value is set to a lower limit, and the cell voltage calculated when the switch has the maximum allowable resistance value. The resistance value of the sensing line may be set to an upper limit.

According to the present invention, since an abnormality of the cell voltage sensing line is originally diagnosed using a cell balancing unit provided for voltage balancing of each battery cell, a separate additional configuration needs to be provided for diagnosing the abnormality of the cell voltage sensing line. There is no cost economic.

In addition, according to the present invention, the control is such that only the odd switch (or even switch) is turned on based on the lowest switch, the highest switch, and the lowest switch without having to turn on or off all the switches. Since the time for diagnosing an abnormality of the cell voltage sensing line can be shortened, the influence on the life of the switch can be minimized.

1 is a view illustrating a state in which an abnormality diagnosis apparatus for a cell voltage sensing line is connected to a battery module through a cell voltage sensing line according to an exemplary embodiment of the present invention.
FIG. 2 is a diagram illustrating currents and voltages appearing in a cell voltage sensing line when only the switch in the lowest state is turned on in the abnormality diagnosis apparatus of FIG. 1.
FIG. 3 is a diagram illustrating current and voltage appearing in a cell voltage sensing line when only the switch at the top of the fault diagnosis apparatus of FIG. 1 is in an ON state.
FIG. 4 is a diagram illustrating currents and voltages appearing in a cell voltage sensing line when only a third switch is turned on based on a switch located at the lowest level in the apparatus for diagnosing the fault of FIG. 1.
FIG. 5 is a diagram illustrating current and voltage appearing in a cell voltage sensing line when only the second switch is in an ON state based on a switch located at the lowest level in the abnormality diagnosis apparatus of FIG. 1.
FIG. 6 is a diagram illustrating current and voltage appearing in a cell voltage sensing line when only the fourth switch is in an ON state with respect to the switch located at the lowest position in the abnormality diagnosis apparatus of FIG. 1.
7 is a flowchart illustrating a method of diagnosing an abnormality of a cell voltage sensing line using an apparatus for diagnosing an abnormality of a cell voltage sensing line according to an exemplary embodiment of the present invention.

Hereinafter, an apparatus and method for diagnosing an abnormality of a cell voltage sensing line according to the present invention will be described in detail with reference to the accompanying drawings. The accompanying drawings are provided by way of example in order to sufficiently convey the technical spirit of the present invention to those skilled in the art, the present invention is not limited to the drawings presented below may be embodied in any other form. have.

1 is a view illustrating a state in which an abnormality diagnosis apparatus for a cell voltage sensing line is connected to a battery module through a cell voltage sensing line according to an exemplary embodiment of the present invention.

As illustrated in FIG. 1, the apparatus 1000 for diagnosing an abnormality of a cell voltage sensing line according to an exemplary embodiment of the present invention includes a plurality of battery cells through cell voltage sensing lines 51, 52, 53, 54, 55, and 56. (11, 12, 13, 14, 15) are connected to the battery module 30 connected in series, the cell balancing unit (101, 102, 103, 104, 105), the voltage detector (210, 220, 230, 240, 250 and the abnormality diagnosis unit 300 may be included.

In FIG. 1, although the battery module 30 is composed of a total of five battery cells 11, 12, 13, 14, and 15, the number of battery cells may be changed in various ways, and for convenience of description only. The number of battery cells is shown as a total of five.

The cell balancing unit 101, 102, 103, 104, 105 is composed of switches 121, 122, 123, 124, 125 and switch resistors 141, 142, 143, 144, 145 connected in series with each other. The sensing lines 51, 52, 53, 54, 55, and 56 are connected in parallel to the respective battery cells 11, 12, 13, 14, and 15. The cell balancing units 101, 102, 103, 104, and 105 are originally configured to balance the voltages of the battery cells 11, 12, 13, 14, and 15, but the abnormality diagnosis unit 300, which will be described later, is described below. Is used for diagnosing abnormalities of the cell voltage sensing lines 51, 52, 53, 54, 55, 56.

The voltage detectors 210, 220, 230, 240, and 250 are connected in parallel to the cell balancing units 101, 102, 103, 104, and 105, and are detected by the voltage detectors 210, 220, 230, 240, and 250. The voltage is transmitted to the abnormality diagnosis unit 300.

The abnormality diagnosis unit 300 controls the operations of the switches 121, 122, 123, 124, and 125, and operates the voltage detectors 210, 220, 230, according to the operations of the switches 121, 122, 123, 124, and 125. The resistance values of the cell voltage sensing lines 51, 52, 53, 54, 55 and 56 are calculated using the voltages detected by the 240 and 250.

Hereinafter, an embodiment in which the abnormality diagnosis unit 300 calculates resistance values of the cell voltage sensing lines 51, 52, 53, 54, 55, and 56 will be described with reference to FIGS. 1 to 4.

Referring to FIG. 1, all of the switches 121, 122, 123, 124, and 125 are turned off in the abnormality diagnosis apparatus 1000 of the cell voltage sensing line.

Referring to FIG. 1, since all the switches 121, 122, 123, 124, and 125 are in an off state, when the voltage of the battery module 30 is referred to as V _T1 , the voltage detectors 210, 220, 230, 240, and 250 are used. ) Is the voltage detected by V _T1 (= V ₁ + V ₂ + V ₃ + V ₄ + V ₅ ). The abnormality diagnosis unit 300 receives the voltage V _T1 when all the switches 121, 122, 123, 124, and 125 are in the off state from the voltage detectors 210, 220, 230, 240, and 250. Here, V ₁ is the voltage of the battery cell 11, V ₂ is the voltage of the battery cell 12, V ₃ is the voltage of the battery cell 13, V ₄ is the voltage of the battery cell 14, V ₅ is It is the voltage of the battery cell 15.

FIG. 2 is a diagram illustrating current and voltage appearing in a cell voltage sensing line when only the switch 121 in the lowest state is turned on in the abnormality diagnosis apparatus of FIG. 1.

As shown in FIG. 2, when only the lowest switch 121 is turned on in the abnormality diagnosis apparatus 1000 of FIG. 1, the resistance value Ra of the lowest cell voltage sensing line 51 and the lowest value are measured. The resistance value Rb of the second cell voltage sensing line 52 may be calculated based on the cell voltage sensing line 51.

Specifically, the abnormality diagnosis unit 300 may transmit a switching signal for operating the switch 121 to the on state to the cell balancing unit 101 at the lowest level, whereby the switch 121 which is in the off state may be It turns on. When the switch 121 is turned on, a current I ₁ flows along a closed circuit including the battery cell 11, the cell voltage sensing line 52, the cell balancing unit 101, and the cell voltage sensing line 51. .

Here, the resistance value R ₁ of the lowest switch resistance 141 is stored in advance in the abnormality diagnosis unit 300, accordingly, the abnormality diagnosis unit 300 is the voltage (V ₁ ) detected by the voltage detector 210 ') Can be used to calculate the current I ₁ (ie I ₁ = V ₁ ' / R ₁ ).

The abnormality diagnosis unit 300 may calculate the resistance value Ra of the cell voltage sensing line 51 as follows.

As described above, the abnormality diagnosis unit 300 sets the voltage V _T1 detected when all the switches 121, 122, 123, 124, and 125 are in an off state to the voltage detectors 210, 220, 230, 240, and 250. (V _T1 = V ₁ + V ₂ + V ₃ + V ₄ + V ₅ ).

Also, as shown in FIG. 2, the abnormality diagnosis unit 300 receives the voltage V _T2 detected from the voltage detection units 210, 220, 230, 240, and 250 when only the lowermost switch 121 is in an on state. (V _T2 = V ₁ '+ V ₂ ' + V ₃ + V ₄ + V ₅ ).

Meanwhile, in FIG. 2, the Kirchhoff's Voltage Law follows a closed circuit including the battery module 30, the cell voltage sensing line 56, the voltage detectors 210, 220, 230, 240 and 250, and the cell voltage sensing line 51. ), The following equation 1 is established.

[Equation 1]

-V _T1 + V _T2 + V _Ra = 0

Since V _Ra is I ₁ × Ra, Equation 1 may be expressed as Equation 2 below.

[Equation 2]

V _Ra = V _T1 -V _T2 = I ₁ × Ra

Summarizing Equation 2, the resistance value Ra of the cell voltage sensing line 51 may be expressed as Equation 3 below.

[Equation 3]

Ra = (V _T1 -V _T2 ) / I ₁

That is, the abnormality diagnosis unit 300 receives the voltage V _T1 detected when all the switches 121, 122, 123, 124, and 125 are turned off from the voltage detectors 210, 220, 230, 240, and 250. After that, the switching control is performed such that only the lowest switch 121 is in an on state, and then the voltage V _T2 detected accordingly is received from the voltage detectors 210, 220, 230, 240, and 250. Accordingly, the resistance value Ra of the lowest cell voltage sensing line 51 can be calculated.

Meanwhile, in FIG. 2, when KVL is applied along a closed circuit including the battery cell 12, the cell voltage sensing line 53, the voltage detector 220, and the cell voltage sensing line 52, Equation 4 below is established. .

[Equation 4]

-V ₂ + V ₂ '-V _Rb = 0

Since V _Rb is I ₁ × Rb, Equation 4 may be expressed as Equation 5 below.

[Equation 5]

V _Rb = V ₂ '-V ₂ = I ₁ × Rb

To sum up Equation 5, the resistance value Rb of the cell voltage sensing line 52 can be expressed as Equation 6 below.

[Equation 6]

Rb = (V ₂ '-V ₂ ) / I ₁

That is, the abnormality diagnosis unit 300 receives the voltage V ₂ detected when all the switches 121, 122, 123, 124, and 125 are in an off state from the voltage detection unit 220, and thereafter, the switch 121 at the lowest level. ) Is controlled to be in the ON state only, and receives the voltage V ₂ ′ detected accordingly from the voltage detection unit 220, based on the lowest cell voltage sensing line 51 according to Equation 6 above. The resistance value Rb of the cell voltage sensing line 52 can be calculated.

FIG. 3 is a diagram illustrating current and voltage appearing in a cell voltage sensing line when only the switch at the top of the fault diagnosis apparatus of FIG. 1 is in an ON state.

As shown in FIG. 3, when only the switch 125 at the top of the fault diagnosis apparatus 1000 of FIG. 1 is turned on, the resistance value Rf of the cell voltage sensing line 56 at the top and the lowest The resistance value Re of the fifth cell voltage sensing line 55 may be calculated based on the cell voltage sensing line 51.

Specifically, the abnormality diagnosis unit 300 may transmit a switching signal for operating the switch 125 to the on state to the cell balancing unit 105 at the highest level, whereby the switch 125 that is in the off state may be It turns on. When the switch 125 is turned on, a current I ₅ flows along a closed circuit including the battery cell 15, the cell voltage sensing line 56, the cell balancing unit 105, and the cell voltage sensing line 55. .

In the fault diagnosis unit 300, the resistance value R ₅ of the switch resistor 145 at the uppermost level is stored in advance, and accordingly, the fault diagnosis unit 300 detects the voltage V ₅ ′ detected by the voltage detector 250. The current I ₅ can be calculated using (i.e., I ₅ = V ₅ '/ R ₅ ).

The abnormality diagnosis unit 300 may calculate the resistance value Rf of the cell voltage sensing line 56 as follows.

As described above, the abnormality diagnosis unit 300 sets the voltage V _T1 detected when all the switches 121, 122, 123, 124, and 125 are in an off state to the voltage detectors 210, 220, 230, 240, and 250. (V _T1 = V ₁ + V ₂ + V ₃ + V ₄ + V ₅ ).

Also, as shown in FIG. 3, the abnormality diagnosis unit 300 receives the voltage V _T3 detected from the voltage detection units 210, 220, 230, 240, and 250 when only the uppermost switch 125 is in an on state. (V _T3 = V ₁ + V ₂ + V ₃ + V ₄ '+ V ₅ ').

Meanwhile, in FIG. 3, when KVL is applied along a closed circuit including the battery module 30, the cell voltage sensing line 56, the voltage detectors 210, 220, 230, 240, and 250, and the cell voltage sensing line 51. Equation (7) holds.

[Equation 7]

-V _T1 + V _Rf + V _T3 = 0

Since V _Rf is I ₅ × Rf, Equation 7 may be expressed as Equation 8 below.

[Equation 8]

V _Rf = V _T1 -V _T3 = I ₅ × Rf

Summarizing Equation 8, the resistance value Rf of the cell voltage sensing line 56 may be expressed as Equation 9 below.

[Equation 9]

Rf = (V _T1 -V _T3 ) / I ₅

That is, the abnormality diagnosis unit 300 receives the voltage V _T1 detected when all the switches 121, 122, 123, 124, and 125 are turned off from the voltage detectors 210, 220, 230, 240, and 250. After that, the switching control is performed such that only the switch 125 at the uppermost level is turned on, and the voltage V _T3 detected accordingly is received from the voltage detectors 210, 220, 230, 240, and 250. Accordingly, the resistance value Rf of the cell voltage sensing line 51 at the highest level can be calculated.

Meanwhile, when KVL is applied along a closed circuit including the battery cell 14, the cell voltage sensing line 55, the voltage detector 240, and the cell voltage sensing line 54 in FIG. 3, Equation 10 is established as follows. .

[Equation 10]

-V ₄ -V _Re + V ₄ '= 0

Since V _Re is I ₅ × Re, Equation 10 may be expressed as Equation 11 below.

[Equation 11]

V _Re = V ₄ '-V ₄ = I ₅ × Re

Summarizing Equation 11, the resistance value Re of the cell voltage sensing line 55 may be expressed as Equation 12 below.

[Equation 12]

Re = (V ₄ '-V ₄ ) / I ₅

That is, the abnormality diagnosis unit 300 receives the voltage V ₄ detected when all the switches 121, 122, 123, 124, and 125 are in an off state from the voltage detection unit 240, and thereafter, the switch 125 at the highest level. ) And the switching control to be in the ON state, and receives the voltage V ₄ ′ detected accordingly from the voltage detection unit 240, based on the lowest cell voltage sensing line 51 according to Equation 12 above. The resistance value Re of the first cell voltage sensing line 55 may be calculated.

FIG. 4 is a diagram illustrating currents and voltages appearing in a cell voltage sensing line when only a third switch is turned on based on a switch located at the lowest level in the apparatus for diagnosing the fault of FIG. 1.

As illustrated in FIG. 4, when only the third switch 123 is turned on based on the switch 121 located at the lowest level in the abnormality diagnosis apparatus 1000 of FIG. 1, the cell voltage sensing line 51 at the lowest level is shown. Based on the reference value, the resistance value Rc of the third cell voltage sensing line 53 and the resistance value Rd of the fourth cell voltage sensing line 54 may be calculated.

Specifically, the abnormality diagnosis unit 300 may transmit a switching signal for operating the switch 123 to an on state to the third cell balancing unit 103 based on the lowest cell balancing unit 101. As a result, the switch 123 in the off state is turned on. When the switch 123 is turned on, a current I ₃ flows along a closed circuit including the battery cell 13, the cell voltage sensing line 54, the cell balancing unit 103, and the cell voltage sensing line 53. .

In the fault diagnosis unit 300, the resistance value R ₃ of the switch resistor 143 is stored in advance. Accordingly, the fault diagnosis unit 300 uses the voltage V ₃ ″ detected by the voltage detector 230. The current I ₃ can be calculated (ie I ₃ = V ₃ "/ R ₃ ).

The abnormality diagnosis unit 300 may calculate the resistance value Rc of the cell voltage sensing line 53 as follows.

In FIG. 4, when KVL is applied along a closed circuit including the battery cell 12, the cell voltage sensing line 53, the voltage detector 220, and the cell voltage sensing line 52, Equation 13 is established.

[Equation 13]

-V ₂ -V _Rc + V ₂ "= 0

Since V _Rc is I ₃ × Rc, Equation 13 may be expressed as Equation 14 below.

[Equation 14]

V _Rc = V ₂ "-V ₂ = I ₃ × Rc

Summarizing Equation 14, the resistance value Rc of the cell voltage sensing line 53 may be expressed as Equation 15 below.

[Equation 15]

Rc = (V ₂ "-V ₂ ) / I ₃

That is, the abnormality diagnosis unit 300 receives the voltage V ₂ detected when all the switches 121, 122, 123, 124, and 125 are in an off state from the voltage detection unit 220, and thereafter, the switch 121 at the lowest level. Switching control such that only the third switch 123 is in an on state, and receives the detected voltage V ₂ ″ from the voltage detector 220, and senses the lowest cell voltage according to Equation 15 below. The resistance value Rc of the third cell voltage sensing line 53 may be calculated based on the line 51.

The abnormality diagnosis unit 300 may calculate the resistance value Rd of the cell voltage sensing line 54 as follows.

In FIG. 4, when KVL is applied along a closed circuit including the battery cell 14, the cell voltage sensing line 55, the voltage detector 240, and the cell voltage sensing line 54, Equation 16 is established.

[Equation 16]

-V ₄ + V ₄ "-V _Rd = 0

Since V _Rd is I ₃ × Rd, Equation 16 may be expressed as Equation 17 below.

[Equation 17]

V _Rd = V ₄ "-V ₄ = I ₃ × Rd

To sum up Equation 17, the resistance value Rd of the cell voltage sensing line 54 can be expressed as Equation 18 below.

Equation 18

Rd = (V ₄ "-V ₄ ) / I ₃

That is, the abnormality diagnosis unit 300 receives the voltage V ₄ , which is detected when all the switches 121, 122, 123, 124, and 125 are in an off state, from the voltage detection unit 240, and thereafter, the switch 121 at the lowest level. Switching control such that only the fourth switch 124 is in an on state, and receives the detected voltage V ₄ ″ from the voltage detector 240 to sense the lowest cell voltage according to Equation 18. The resistance value Rd of the fourth cell voltage sensing line 54 may be calculated based on the line 51.

As described above, the abnormality diagnosis unit 300 detects the voltage detected when all the switches 121, 122, 123, 124, and 125 are in an off state, and when only the lowest switch 121 is in the on state. When receiving the voltage, the resistance value of the lowest cell voltage sensing line 51 and the resistance value of the cell voltage sensing line 52 directly above can be calculated.

In addition, the abnormality diagnosis unit 300 delivers a voltage detected when all the switches 121, 122, 123, 124, and 125 are in an off state, and a voltage that is detected when only the uppermost switch 125 is in an on state. When receiving, the resistance value of the cell voltage sensing line 56 at the highest level and the resistance value of the cell voltage sensing line 55 immediately below it can be calculated.

In addition, when the abnormality diagnosis unit 300 receives a voltage detected when only the odd switch 123 is turned on based on the switch 121 located at the lowest level, the cell including the odd switch 123 is included. The resistance values of the cell voltage sensing lines 53 and 54 connected to both ends of the balancing unit 103 may be calculated.

Accordingly, in the present embodiment, the cell voltage sensing lines 51, 52, 53, 54, 55, 56 of the battery module 30 in which five battery cells 11, 12, 13, 14, and 15 are connected in series are connected. Although the method of calculating the resistance value of is described, the voltage detected when all the switches are in the off state, the voltage detected when only the lowermost switch is in the on state, and the detection value when only the uppermost switch is in the on state. By using the voltage and the voltage detected when only the odd switch is in the ON state based on the lowest switch, the abnormality diagnosis unit 300 includes the resistance of the cell voltage sensing line in all cases where the number of battery cells is four or more. You can calculate the value.

In the above description, the cell voltage sensing lines 51, 52, 53, and 54 are provided by using the voltage detected when only the odd-numbered switch 123 is turned on, based on the lowest switch 121, referring to FIGS. 1 to 4. Although the embodiment of calculating the resistance values of the first and second switches 55 and 56 has been described, the cell is also used by using the voltage detected when only the even switches 122 and 124 are turned on with respect to the lowest switch 121. The resistance values of the voltage sensing lines 51, 52, 53, 54, 55, and 56 may be calculated. In this case, the method of calculating the resistance values Ra, Rb, Re, and Rf of the cell voltage sensing lines 51, 52, 55, and 56 is the same as described above with reference to FIGS. Referring to 6, only the method of calculating the resistance values Rc and Rd of the cell voltage sensing lines 53 and 54 will be described.

FIG. 5 is a diagram illustrating current and voltage appearing in a cell voltage sensing line when only the second switch is in an ON state based on a switch located at the lowest level in the abnormality diagnosis apparatus of FIG. 1.

As shown in FIG. 5, when only the second switch 122 is turned on based on the switch 121 located at the lowest level in the abnormality diagnosis apparatus 1000 of FIG. 1, the cell voltage sensing line 51 at the lowest level is shown. Based on this, the resistance value Rc of the third cell voltage sensing line 53 can be calculated.

Specifically, the abnormality diagnosis unit 300 may transmit a switching signal for operating the switch 122 to an on state to the second cell balancing unit 102 based on the lowest cell balancing unit 101. As a result, the switch 122 in the off state is turned on. When the switch 122 is turned on, a current I ₂ flows along a closed circuit including the battery cell 12, the cell voltage sensing line 53, the cell balancing unit 102, and the cell voltage sensing line 52. .

In the fault diagnosis unit 300, the resistance value R ₂ of the switch resistor 142 is stored in advance. Accordingly, the fault diagnosis unit 300 uses the voltage V ₂ ″ detected by the voltage detector 220. The current I ₂ can be calculated (ie I ₂ = V ₂ "/ R ₂ ).

The abnormality diagnosis unit 300 may calculate the resistance value Rc of the cell voltage sensing line 53 as follows.

In FIG. 5, when KVL is applied along a closed circuit including the battery cell 13, the cell voltage sensing line 54, the voltage detector 230, and the cell voltage sensing line 53, Equation 19 is established.

[Equation 19]

-V ₃ + V ₃ "-V _Rc = 0

Since V _Rc is I ₂ × Rc, Equation 19 may be expressed as Equation 20 below.

[Equation 20]

V _Rc = V ₃ "-V ₃ = I ₂ × Rc

Summarizing Equation 20, the resistance value Rc of the cell voltage sensing line 53 may be expressed as Equation 21 below.

[Equation 21]

Rc = (V ₃ "-V ₃ ) / I ₂

That is, the abnormality diagnosis unit 300 receives the voltage V ₃ detected when all the switches 121, 122, 123, 124, and 125 are in an off state from the voltage detection unit 230, and thereafter, the switch 121 at the lowest level. Switching control such that only the second switch 122 is turned on, and receives the detected voltage V ₃ ″ from the voltage detector 230 and senses the lowest cell voltage according to Equation 21. The resistance value Rc of the third cell voltage sensing line 53 may be calculated based on the line 51.

FIG. 6 is a diagram illustrating current and voltage appearing in a cell voltage sensing line when only the fourth switch is turned on based on the switch located at the lowest level in the abnormality diagnosis apparatus of FIG. 1.

As shown in FIG. 6, when only the fourth switch 124 is turned on based on the switch 121 located at the lowest level in the abnormality diagnosis apparatus 1000 of FIG. 1, the cell voltage sensing line 51 at the lowest level is shown. Based on this, the resistance value Rd of the fourth cell voltage sensing line 54 can be calculated.

Specifically, the abnormality diagnosis unit 300 may transmit a switching signal for operating the switch 124 to the on state to the fourth cell balancer 104 based on the lowest cell balancer 101. As a result, the switch 124 in the off state is turned on. When the switch 124 is turned on, a current I ₄ flows along a closed circuit including the battery cell 14, the cell voltage sensing line 55, the cell balancing unit 104, and the cell voltage sensing line 54. .

In the fault diagnosis unit 300, the resistance value R ₄ of the switch resistor 144 is stored in advance, and accordingly, the fault diagnosis unit 300 uses the voltage V ₄ ″ ″ detected by the voltage detector 240. Current I ₄ can be calculated (ie I ₄ = V ₄ '"/ R ₄ ).

The abnormality diagnosis unit 300 may calculate the resistance value Rd of the cell voltage sensing line 54 as follows.

In FIG. 6, when KVL is applied along a closed circuit including the battery cell 13, the cell voltage sensing line 54, the voltage detector 230, and the cell voltage sensing line 53, Equation 22 is established.

[Equation 22]

-V ₃ -V _Rd + V ₃ '"= 0

Since V _Rd is I ₄ × Rd, Equation 22 may be expressed as Equation 23 below.

[Equation 23]

V _Rd = V ₃ '"-V ₃ = I ₄ × Rd

Summarizing Equation 23, the resistance value Rd of the cell voltage sensing line 54 may be expressed as Equation 24 below.

[Equation 24]

Rd = (V ₃ '"-V ₃ ) / I ₄

That is, the abnormality diagnosis unit 300 receives the voltage V ₃ detected when all the switches 121, 122, 123, 124, and 125 are in an off state from the voltage detection unit 230, and thereafter, the switch 121 at the lowest level. Switching control such that only the fourth switch 124 is in an on state, and receives the detected voltage V ₃ '"from the voltage detector 230, and according to Equation 24, the lowest cell voltage. The resistance value Rd of the fourth cell voltage sensing line 54 may be calculated based on the sensing line 51.

As described above, even when the abnormality diagnosis unit 300 receives the voltage detected when only the even-numbered switches 122 and 124 are turned on with respect to the switch 121 that is the lowest, all the cell voltages are sensed. The resistance values of the lines 51, 52, 53, 54, 55 and 56 can be calculated.

In addition, although the description is omitted here, when only the second switch 122 on the basis of the switch 121 in the lowest state, as described above with reference to FIG. 4, the cell balancing unit including the second switch 122 The resistance values of the cell voltage sensing lines 52 and 53 connected to both ends of the 102 can be calculated, and even when only the fourth switch 124 is turned on based on the switch 121 located at the lowest level, As described with reference to FIG. 4, the resistance values of the cell voltage sensing lines 54 and 55 connected to both ends of the cell balancing unit 104 including the fourth switch 124 may be calculated.

Accordingly, in the present embodiment, the cell voltage sensing lines 51, 52, 53, 54, 55, 56 of the battery module 30 in which five battery cells 11, 12, 13, 14, and 15 are connected in series are connected. Although the method of calculating the resistance value of is described, the voltage detected when all the switches are in the off state, the voltage detected when only the lowermost switch is in the on state, and the detection value when only the uppermost switch is in the on state. When the voltage and the voltage detected when only the even switch is turned on based on the lowest switch are used, the abnormality diagnosis unit 300 may determine the resistance of the cell voltage sensing line in all cases where the number of battery cells is three or more. You can calculate the value.

In the above description, in order to calculate resistance values of the cell voltage sensing lines 51, 52, 53, 54, 55, and 56, the odd-numbered switch 123 or the even-numbered switch 122, Although the method of controlling only 124 to be in an on state has been described, there is also a method of controlling all switches 121, 122, 123, 124, and 125 to be in an on state alternately. That is, in order to calculate the resistance values of the cell voltage sensing lines 51, 52, 53, 54, 55 and 56, the control is performed so that only the lowest switch 121 is turned on, and then the cell voltage sensing lines 51 and 52. Calculate the resistance values Ra and Rb, control so that only the second switch 122 is turned on, calculate the resistance value Rc of the cell voltage sensing line 53, and turn on only the third switch 123. After controlling to be in a state, the resistance value Rd of the cell voltage sensing line 54 is calculated, and the fourth switch 124 is controlled to be in an ON state, and then the resistance value Re of the cell voltage sensing line 55 is adjusted. There is also a method such as calculating the resistance value Rf of the cell voltage sensing line 56 after controlling the switch 125 at the highest level to be in an ON state.

However, this method is compared to the method of controlling only the odd-numbered switch 123 or the even-numbered switch 122 and 124 to be turned on based on the switch 121 located at the lowest level, and the cell voltage sensing lines 51, 52, and 53. , 54, 55, 56 takes longer to diagnose the abnormality, and there is a concern that the life of the switches 121, 122, 123, 124, and 125 may also be shortened due to unnecessary switching operations.

Accordingly, only the odd-numbered switch 123 or the even-numbered switch 122, 124 is turned on based on the lowest switch 121 without the need to turn on / off all the switches 121, 122, 123, 124, and 125. Controlling to be in a state shortens the time for diagnosing abnormality of the cell voltage sensing lines 51, 52, 53, 54, 55, 56 and affects the life of the switches 121, 122, 123, 124, 125. There is an advantage to minimize the.

The abnormality diagnosis unit 300 compares the resistance values Ra, Rb, Rc, Rd, Re, and Rf of the cell voltage sensing lines 51, 52, 53, 54, 55, and 56 with the reference resistance value. The abnormality of the voltage sensing lines 51, 52, 53, 54, 55, 56 is diagnosed.

The reference resistance value is compared with the resistance values Ra, Rb, Rc, Rd, Re, and Rf of the cell voltage sensing lines 51, 52, 53, 54, 55, and 56 calculated by the abnormality diagnosis unit 300. Through this, the cell voltage sensing lines 51, 52, 53, 54, 55, and 56 are used as criteria for determining whether there is an error.

The reference resistance value is the resistance of the cell voltage sensing lines 51, 52, 53, 54, 55, 56 calculated when the switches 121, 122, 123, 124, 125 have the minimum allowable resistance value Rmim. The cell voltage sensing lines 51, 52, 53, 54, 55, 56 calculated when the value is set to the lower limit and the switches 121, 122, 123, 124, 125 have the maximum allowable resistance value Rmax. ) May be set to an upper limit.

The resistance value of the switches 121, 122, 123, 124, 125 is ideally 0, but in practice it may have a minimum allowable resistance value Rmim and a maximum allowable resistance value Rmax depending on the specification. In general, the resistance values of the switches 121, 122, 123, 124, and 125 are very small compared to the resistance values of the switch resistors 141, 142, 143, 144, and 145. Setting the reference resistance value in consideration of the resistance values 124 and 125 may contribute to accurately diagnose the abnormality of the cell voltage sensing lines 51, 52, 53, 54, 55 and 56.

The reference resistance value may be set in advance in the abnormality diagnosis unit 300. Accordingly, the abnormality diagnosis unit 300 may include the resistance values Ra of the cell voltage sensing lines 51, 52, 53, 54, 55, and 56. The abnormalities of the cell voltage sensing lines 51, 52, 53, 54, 55, and 56 are diagnosed by comparing the Rb, Rc, Rd, Re, and Rf with a preset reference resistance value.

The abnormality diagnosis unit 300 calculates a reference resistance value in which the resistance values Ra, Rb, Rc, Rd, Re, and Rf of the calculated cell voltage sensing lines 51, 52, 53, 54, 55, and 56 are preset. The deviation may generate a warning signal, and the generated warning signal may be transmitted to a lamp operation controller (not shown). When the lamp operation controller receives a warning signal from the abnormality diagnosis unit 300, the cell voltage sensing lines 51 and 52 may be activated by a method of turning on a lamp provided in an instrument panel of an electric vehicle or a hybrid vehicle. , 53, 54, 55, 56) can be notified to the user.

7 is a flowchart illustrating a method of diagnosing an abnormality of a cell voltage sensing line using an apparatus for diagnosing an abnormality of a cell voltage sensing line according to an exemplary embodiment of the present invention.

The apparatus 1000 for diagnosing an abnormality of a cell voltage sensing line according to an exemplary embodiment of the present invention may include a plurality of battery cells 11 through the cell voltage sensing lines 51, 52, 53, 54, 55, and 56 as described above. , 12, 13, 14, 15 are connected to the battery module 30 connected in series.

The abnormality diagnosis apparatus 1000 of the cell voltage sensing line includes a switch 121, 122, 123, 124, and 125 and a switch resistor 141, 142, 143, 144, and 145 connected in series with each other. Cell balancing units 101, 102, 103, 104, 105 connected in parallel to the respective battery cells 11, 12, 13, 14, and 15 through 51, 52, 53, 54, 55, and 56, The voltage detectors 210, 220, 230, 240, and 250 connected in parallel to the cell balancing units 101, 102, 103, 104, and 105, and the switches 121, 122, 123, 124, and 125. The cell voltage sensing line 51 is controlled by using the voltage detected by the voltage detectors 210, 220, 230, 240, and 250 according to the operation of the switches 121, 122, 123, 124, and 125. , 52, 53, 54, 55, and 56 may include the abnormality diagnosis unit 300 for diagnosing the abnormality.

In the method for diagnosing an abnormality of the cell voltage sensing line according to an exemplary embodiment of the present disclosure, first, the abnormality diagnosis unit 300 may operate the voltage detectors 210 and 220 according to the operations of the switches 121, 122, 123, 124, and 125. The resistance values of the cell voltage sensing lines 51, 52, 53, 54, 55, and 56 are calculated using the voltages detected by the signals 230, 240, and 250 (S100).

Here, the resistance values Ra, Rb, Rc, Rd, Re, and Rf of the cell voltage sensing lines 51, 52, 53, 54, 55, and 56 are as described above with reference to FIGS. 1 to 4. Voltage detected when all of the switches 121, 122, 123, 124, and 125 are in an off state, and only when the switch 121, the lowest of the switches 121, 122, 123, 124, and 125, is in an on state The odd number switch based on the detected voltage, the voltage detected when only the switch 125 at the top of the switches 121, 122, 123, 124, and 125 is in an on state, and the switch 121 at the bottom thereof. It may be calculated using the voltage detected when only 123 is in the on state.

Alternatively, the resistance values Ra, Rb, Rc, Rd, Re, and Rf of the cell voltage sensing lines 51, 52, 53, 54, 55, and 56 may have been previously described with reference to FIGS. 1 to 3, 5, and 6. As described with reference to the switch 121, 122, 123, 124, 125 is the lowest voltage of the switch 121, 122, 123, 124, 125, the voltage detected when all the off state Voltage detected when in the ON state, voltage detected when only the switch 125 at the top of the switches 121, 122, 123, 124, and 125 is in the ON state, and the switch 121 in the lowest state. It can be calculated using the voltage detected when only the even-numbered switch (122, 124) is in the on state.

After the abnormality diagnosis unit 300 calculates resistance values of the cell voltage sensing lines 51, 52, 53, 54, 55, and 56, the cell voltage sensing lines 51, 52, 53, 54, 55, and 56 are measured. The resistance values Ra, Rb, Rc, Rd, Re, and Rf of the cell voltage sensing lines 51, 52, 53, 54, 55, and 56 are diagnosed by comparing them with the reference resistance value (S200).

Here, the reference resistance value is a cell voltage sensing line 51, 52, 53, 54, 55, 56 calculated when the switches 121, 122, 123, 124, and 125 have the minimum allowable resistance value Rmim. Cell voltage sensing lines 51, 52, 53, 54, 55, which are calculated when the resistance value of is set to the lower limit and the switches 121, 122, 123, 124, 125 have the maximum allowable resistance value Rmax. , 56) may be set to an upper limit.

The reference resistance value may be preset in the abnormality diagnosis unit 300, and the abnormality diagnosis unit 300 may calculate the resistance value Ra of the calculated cell voltage sensing lines 51, 52, 53, 54, 55, and 56. If it is determined that Rb, Rc, Rd, Re, and Rf are out of a predetermined reference resistance value, a warning signal may be generated, and the generated warning signal may be transmitted to a lamp operation controller (not shown). When the lamp operation controller receives a warning signal from the abnormality diagnosis unit 300, the cell voltage sensing lines 51 and 52 may be activated by a method of turning on a lamp provided in an instrument panel of an electric vehicle or a hybrid vehicle. , 53, 54, 55, 56) can be notified to the user.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above-described embodiments, which can be variously modified and modified by those skilled in the art. Modifications are possible. Therefore, the technical idea of the present invention should be understood only by the claims, and all equivalent or equivalent modifications thereof will belong to the scope of the technical idea of the present invention.

11, 12, 13, 14, 15: battery cell
30: battery module
51, 52, 53, 54, 55, 56: cell voltage sensing line
101, 102, 103, 104, 105: cell balancing unit
121, 122, 123, 124, 125: switch
141, 142, 143, 144, 145: switch resistor
210, 220, 230, 240, 250: voltage detector
300: abnormal diagnosis unit
1000: abnormal diagnosis device

Claims (8)

A device for diagnosing an abnormality of the cell voltage sensing line by connecting a plurality of battery cells connected in series through a cell voltage sensing line.
A cell balancing unit comprising a switch and a switch resistor connected in series to each other and connected in parallel to each battery cell through the cell voltage sensing line;
A voltage detector connected in parallel to the cell balancing unit; And
Controlling the operation of the switch, calculating a resistance value of the cell voltage sensing line by using the voltage detected by the voltage detector according to the operation of the switch, and comparing the resistance value of the cell voltage sensing line with a reference resistance value. And an abnormality diagnosis unit for diagnosing an abnormality of the cell voltage sensing line.
The method of claim 1,
The abnormality diagnosis unit,
A voltage detected when all of the switches are in an off state, a voltage detected when only the lowest switch of the switches is in an on state, a voltage detected when only a switch of the highest state of the switches is in an on state, and the lowest value The apparatus for diagnosing abnormality of a cell voltage sensing line, wherein the resistance value of the cell voltage sensing line is calculated using a voltage detected when only an odd number of switches is in an ON state based on a switch in the circuit.
The method of claim 1,
The abnormality diagnosis unit,
A voltage detected when all of the switches are in an off state, a voltage detected when only the lowest switch of the switches is in an on state, a voltage detected when only a switch of the highest state of the switches is in an on state, and the lowest value The apparatus for diagnosing abnormality of a cell voltage sensing line, wherein the resistance value of the cell voltage sensing line is calculated by using a voltage detected when only an even number of switches is on.
The method of claim 1,
The reference resistance value is a cell voltage sensing calculated when the resistance value of the cell voltage sensing line calculated when the switch has the minimum allowable resistance value is set to a lower limit, and the cell voltage sensing calculated when the switch has the maximum allowable resistance value. An apparatus for diagnosing abnormality in a cell voltage sensing line, wherein the resistance value of the line is set to an upper limit.
A device in which a plurality of battery cells are connected to a battery module connected in series through a cell voltage sensing line, comprising a switch and a switch resistor connected in series with each other, and a cell balancing unit connected in parallel to each battery cell through the cell voltage sensing line. ; A voltage detector detecting a voltage connected in parallel to the cell balancing unit; And an abnormality diagnosis unit configured to control an operation of the switch and diagnose an abnormality of the cell voltage sensing line using a voltage detected by the voltage detector according to the operation of the switch. As a method of diagnosing abnormalities,
Calculating a resistance value of the cell voltage sensing line by using the voltage detected by the voltage detector by the fault diagnosis unit according to an operation of the switch; And
And diagnosing an abnormality of the cell voltage sensing line by comparing the resistance value of the cell voltage sensing line with a reference resistance value.
The method of claim 5,
Calculating the resistance value of the cell voltage sensing line,
A voltage detected when all of the switches are in an off state, a voltage detected when only the lowest switch of the switches is in an on state, a voltage detected when only a switch of the highest state of the switches is in an on state, and the lowest value And a resistance value of the cell voltage sensing line is calculated using a voltage detected when only an odd number of switches is on, based on a switch in the cell voltage sensing line.
The method of claim 5,
Calculating the resistance value of the cell voltage sensing line,
A voltage detected when all of the switches are in an off state, a voltage detected when only the lowest switch of the switches is in an on state, a voltage detected when only a switch of the highest state of the switches is in an on state, and the lowest value And a resistance value of the cell voltage sensing line is calculated using a voltage detected when only an even number switch is in an on state based on a switch in the cell voltage sensing line.
The method of claim 5,
The reference resistance value is a cell voltage sensing calculated when the resistance value of the cell voltage sensing line calculated when the switch has the minimum allowable resistance value is set to a lower limit, and the cell voltage sensing calculated when the switch has the maximum allowable resistance value. An error diagnosis method for a cell voltage sensing line, wherein the resistance value of the line is set to an upper limit.

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