KR20190048687A - Apparatus and method for calculating correction coefficient of current to estimate soc of battery - Google Patents

Abstract

According to the present invention, provided is a current correction coefficient calculation apparatus for estimating a state of charge (SOC) of a battery, which is to accurately estimate the SOC of a battery. In the present invention, after a current correction coefficient update unit may calculate a coefficient to match a state of charge based on current (SOCi) calculated by an SOCi calculation unit with a state of charge based on voltage (SOCv) calculated by an SOCv calculation unit, the SOC of a battery can be accurately measured only by SOCi calculation by updating the current correction coefficient to the calculated coefficient.

Description

[0001] APPARATUS AND METHOD FOR CALCULATING CORRECTION COEFFICIENT OF CURRENT TO ESTIMATE SOC OF BATTERY [0002]

The present invention relates to a current correction coefficient calculation apparatus and method for accurately estimating a remaining capacity (SOC: State Of Charge) of a battery.

BACKGROUND ART [0002] Recently, as electric vehicles and hybrid vehicles are mass-produced, there is a demand for a technology for accurately estimating the remaining capacity of a battery in order to prevent overcharging and overdischarge of a battery mounted thereon and to improve cycle life.

Hereinafter, the remaining capacity calculated based on the current flowing in the battery is referred to as SOCi (State Of Charge based on current), the remaining capacity calculated based on the voltage across the battery is referred to as SOCv (State Of Charge based on voltage) .

In a conventional apparatus for estimating remaining capacity of a battery, there is an apparatus which calculates the SOCi by integrating the magnitude of the charged and discharged current, and sets the SOCi as the remaining capacity of the battery. However, SOCi has a problem that the current measurement error and the quantization error continue to accumulate during the current integration process, resulting in a difference from the actual remaining capacity of the battery.

On the other hand, although it can be considered that the SOCv is the remaining capacity of the battery, the SOCv can be used only when the current flowing in the battery corresponds to the low current section (typically, the charging / discharging current flowing in the battery is 3A or less) The accurate remaining capacity can be estimated. Therefore, when the charge / discharge current flows in the battery, the accuracy is deteriorated.

Accordingly, when the battery charging rate calculating device disclosed in Patent Document 1 detects switching between charging and discharging of the battery, the estimated impedance voltage value is calculated from the measured current value and the measured voltage value, and the estimated impedance voltage value and the measured voltage value Lt; / RTI > Thereafter, the battery charging rate calculating device determines either the SOCv based on the estimated open-circuit voltage value thus calculated or the SOCi based on the integrated current value as the remaining capacity of the battery.

The battery charging rate calculation device disclosed in Patent Document 2 calculates the estimated open-circuit voltage value by subtracting the estimated impedance voltage based on the actual temperature and the measured current value of the battery from the measured voltage value, The remaining capacity of the battery is calculated using one SOCv and the SOCi based on the integrated current value.

However, according to the method of predicting the remaining capacity of the battery by adopting the SOCi calculated through the current integration as the remaining capacity of the battery in advance and adopting the SOCv calculated at a predetermined time as the remaining capacity of the battery instead of the SOCi, 1, a jump phenomenon of the remaining capacity occurs in the low current section.

That is, FIG. 1 is a diagram illustrating a state in which a residual capacity jumping phenomenon occurs in a low-current section when estimating the remaining capacity of the battery through the apparatus for estimating remaining capacity of a conventional battery. As described above, the current accumulation process for calculating the SOCi is caused by a difference between the actual remaining capacity of the battery due to the measurement error of the current and accumulation of the quantization error.

Japanese Patent Publication No. 3767150 Japanese Patent Application Laid-Open No. 2006-58114

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems as described above, and it is an object of the present invention to provide a method and apparatus for accurately estimating a remaining capacity of a battery using only SOCi calculated by integrating a current flowing in the battery, And an object of the present invention is to provide an apparatus and a method for calculating correction coefficients.

According to an aspect of the present invention, there is provided an apparatus for calculating a current correction coefficient for estimating a remaining capacity of a battery, the apparatus comprising: a current measuring unit for measuring current flowing in the battery; A temperature measuring unit for measuring a temperature of the battery; A voltage measuring unit for measuring a voltage across both ends of the battery; Wherein the current measuring unit obtains a current measured by the current measuring unit and a temperature of the battery measured by the temperature measuring unit, multiplies the current correction coefficient provided according to the magnitude of the current and the temperature of the battery with the obtained magnitude of the current, An SOCi calculating unit for calculating a state of charge based on current (SOCi) by multiplying the product of the current correction coefficient and the obtained current magnitude; A current average value calculation unit for obtaining a current measured by the current measurement unit and calculating an average value of the current in a predetermined time interval through a moving average filter; An OCV calculating unit for calculating an OCV (Open Circuit Voltage) by applying a current measured by the current measuring unit or a voltage measured by the voltage measuring unit to the battery equivalent circuit model after the predetermined time interval; An SOCv calculating unit for calculating a state of charge based on voltage (SOCv) using the OCV calculated by the OCV calculating unit; And a current correction coefficient update unit updating a current correction coefficient corresponding to the average value of the current and the battery temperature in the predetermined time interval with the coefficient after calculating a coefficient to make the SOCi coincide with the SOCv do.

Here, the preset time interval may be a time interval before the current measured by the current measuring unit enters the low current interval.

Here, when the current measured by the current measuring unit after the preset time interval enters the low-current period, the OCV calculating unit may calculate the OCV by the voltage measuring unit after a predetermined time at the time of entering the low- Only the measured voltage is applied to the battery equivalent circuit model to calculate the OCV.

Alternatively, the OCV calculation unit may apply the current measured by the current measuring unit and the voltage measured by the voltage measuring unit to the battery equivalent circuit model and the adaptive filter after the preset time interval, And the OCV can be calculated using the parameter.

Meanwhile, a current correction coefficient calculation method for estimating a remaining capacity of a battery according to the present invention includes: acquiring a current measured by a current measuring unit and a temperature of a battery measured by a temperature measuring unit, Calculating a SOCi by multiplying a current correction coefficient provided according to a temperature of the current correction coefficient with a magnitude of the obtained current and integrating a product of the current correction coefficient and the obtained magnitude of the current; Obtaining a current measured by the current measuring unit and calculating an average value of the current in a predetermined time interval through a moving average filter; Calculating an OCV by applying a current measured by the current measuring unit or a voltage measured by the voltage measuring unit to the battery equivalent circuit model after the predetermined time period; Calculating SOCv using the OCV; And updating the current correction coefficient corresponding to the average value of the current and the temperature of the battery in the preset time interval with the coefficient after calculating the coefficient to make the SOCi coincide with the SOCv.

Here, the preset time interval may be a time interval before the current measured by the current measuring unit enters the low current interval.

Here, the calculating of the OCV may include: when the current measured by the current measuring unit is in the low current period after the predetermined time period, It is possible to calculate the OCV by applying only the voltage measured by the battery equivalent circuit model to the battery equivalent circuit model.

Alternatively, the step of calculating the OCV may include applying a current measured by the current measuring unit and a voltage measured by the voltage measuring unit to the battery equivalent circuit model and the adaptive filter after the predetermined time period, A parameter used in the equivalent circuit model is calculated, and the OCV can be calculated using the parameter.

The current correction coefficient calculated by the present invention can be utilized for correcting the magnitude of the current flowing in the battery when the current flowing through the battery is accumulated. Accordingly, the remaining capacity of the battery can be accurately estimated by SOCi calculation alone.

FIG. 1 is a diagram illustrating a state in which a residual capacity jumping phenomenon occurs in a low-current section when a remaining capacity of a battery is estimated through a remaining capacity estimating apparatus of a conventional battery.
2 is a diagram schematically showing a current correction coefficient calculation apparatus according to an embodiment of the present invention.
3 is a diagram illustrating a section in which the SOCi and the SOCv are calculated and a section in which the average value of the current is calculated through the current correction coefficient calculation apparatus according to an embodiment of the present invention.
4 is a diagram exemplifying a battery equivalent circuit model.
5 is a flowchart of a current-correction-coefficient calculating method according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. And a detailed description of known functions and configurations that may unnecessarily obscure the gist of the present invention will be omitted.

2 is a diagram schematically showing a current correction coefficient calculation apparatus according to an embodiment of the present invention.

The current correction coefficient calculation apparatus according to an embodiment of the present invention includes a current measurement unit 10, a temperature measurement unit 20, a voltage measurement unit 30, an SOCi calculation unit 40, a current average value calculation unit 50, An OCV calculation unit 60, an SOCv calculation unit 70, and a current correction coefficient update unit 80. [

The current measuring unit 10 measures a current (a charging current or a discharging current) flowing in the battery, and may include a current sensor for measuring the current.

However, when there is an abnormality in the current sensor, there is a possibility that the magnitude of the current can not be accurately measured (that is, a measurement error occurs in the current), and SOCi indicates the magnitude of the current measured by the current measuring unit 10, The quantization error is inevitably generated in the process.

Accordingly, the present invention proposes a method of calculating the current correction coefficient for correcting the magnitude of the current measured by the current measuring unit 10, so that the remaining capacity of the battery can be accurately estimated by only SOCi calculation.

The temperature measuring unit 20 measures the temperature of the battery, and the voltage measuring unit 30 measures the voltage across the battery.

3 is a diagram illustrating a section in which the SOCi and the SOCv are calculated and a section in which the average value of the current is calculated through the current correction coefficient calculation apparatus according to an embodiment of the present invention.

3, the SOCi calculating unit 40 acquires a current from the current measuring unit 10 until a current starts flowing from the battery to a low current period, The temperature of the battery measured by the measuring unit 20 is also obtained.

Thereafter, the SOCi calculating unit 40 multiplies the current correction coefficient prepared according to the magnitude of the current and the temperature of the battery with the obtained magnitude of the current, and calculates the SOCi by integrating the product of the current correction coefficient and the obtained magnitude of the current .

Table 1 below shows the current correction coefficients prepared according to the magnitude of the current and the temperature of the battery.

Battery temperature (℃) -30 -20 -10 0 15 25 50

C-rate



Discharge
-1.0 One One One One One One One -0.5 One One One One One One One -0.3 One One One One One One One
charge
0.3 One One One One One One One 0.5 One One One One One One One 1.0 One One One One One One One

As shown in Table 1, the SOCi calculating unit 40 may previously store the current correction coefficients prepared in accordance with the magnitude of the current (C-rate) and the temperature of the battery (占 폚) in the form of a lookup table. The SOCi calculating unit 40 may store the current correction coefficient by setting the current correction coefficient to 1, but the current correction coefficient may be stored in any value other than 1 (except for 0).

In Table 1, the magnitude of the current is represented by C-rate (= current magnitude (A) / battery capacity (Ah)) because the current correction coefficient calculated according to one embodiment of the present invention is (A) of the current flowing in the battery.

In Table 1, the C-rate is positive when the battery is in a charged state and the C-rate is negative when the battery is in a discharged state. This indicates that the direction of the current This is because they are different from each other.

Equation (1) below is an expression that SOCi is calculated by multiplying the product of the current correction coefficient (alpha) and the obtained magnitude (i) of the current.

[Equation 1]

However, as shown in Table 1, when the current correction coefficients provided according to the magnitude of the current and the temperature of the battery are all set to 1, since the SOCi calculated through the current integration is different from the actual SOC of the battery, Modifications need to be applied to the coefficients.

The current average value calculation unit 50 acquires a current measured by the current measurement unit 10 and calculates an average value of the current in a predetermined time interval through a moving average filter. More specifically, the current average value calculation section 50 can calculate an average value of currents in a time interval before the current measured by the current measurement section 10 enters the low current section. For example, The current measured by the current measuring unit 10 may be a time period one minute before the current enters the low current period.

The current average value calculation unit 50 calculates the average value of the currents in order to determine a value representative of the entire SOCi calculation period. If the average value of the current calculated by the current average value calculation unit 50 is 0.5C-rate and the battery temperature when the average value of the current is calculated is 15 ° C, When the corresponding current correction coefficient becomes the target of update and the average value of the current calculated by the current average value calculation unit 50 is -0.3C-rate and the battery temperature when the average value of the current is calculated is -20 ° C , The current correction coefficients corresponding to -0.3C-rate and -20 DEG C in Table 1 are subject to update.

3, the OCV calculating unit 60 calculates the current measured by the current measuring unit 10 or the voltage measured by the voltage measuring unit 30 after the predetermined time interval from the battery equivalent circuit model < RTI ID = 0.0 > To calculate the OCV.

4 is a diagram exemplifying a battery equivalent circuit model. In the OCV calculation unit 60, an equivalent circuit model of the battery as shown in Fig. 4 may be stored in advance.

Generally, a battery mounted on a vehicle flows a low current of 3A or less without starting.

FIG. 3 shows a period in which such a low current flows. The low current is very small compared with the charge / discharge current of the battery. Therefore, if the magnitude of the current measured by the current measuring unit 110 after the predetermined time interval corresponds to the low current, the magnitude of the current can be approximated to zero.

However, even when the current flowing in the battery enters the low current section, the voltage applied across the battery takes a certain time until the battery is turned on by the capacitance component as shown in Fig.

Accordingly, when the current measured by the current measuring unit 10 enters the low-current period after a predetermined time period, the OCV calculating unit 60 determines that the current measured by the current- , And the voltage (V) measured by the voltage measuring unit 120 can be calculated as OCV.

Alternatively, the OCV calculating unit 60 may calculate the current measured by the current measuring unit 110 and the voltage measured by the voltage measuring unit after adaptation of the battery equivalent circuit model as shown in FIG. 4, A parameter used in the battery equivalent circuit model may be calculated by applying it to a filter (adaptive filter), and the OCV may be calculated using the parameter.

The modeling object of the battery equivalent circuit shown in Fig. 4 is a lithium polymer battery (LiPB). Elements such as a resistor and a capacitor included in the equivalent circuit model have the same meanings as in Table 2, respectively.

I Current (charge: (+) / discharge (-)) V Terminal Voltage V _o (= OCV) Open Circuit Voltage R ₁ Lumped Interfacial Resistances R ₂ Lumped Series Resistances C Electric Double Layer Capacitor

In FIG. 4, R ₂ means the resistance in the electrode, and R ₁ and C mean an electric double layer occurring at the interface between the electrode and the electrode (or the interface between the electrode and the separator). Each parameter (R ₁ , R ₂ , C) can usually be obtained through a first-principle model or experimentally. The equivalent circuit model shown in FIG. 4 can be mathematically expressed by Equation (2).

&Quot; (2) "

In Equation (2), it can be seen that the OCV can be obtained by obtaining parameters corresponding to each element constituting the equivalent circuit model. That is, it is an object of battery modeling according to the present invention to obtain each parameter and obtain the OCV by substituting the obtained parameter into Equation (2).

Equation (2) can be derived through the following procedure. In the battery equivalent circuit model of FIG. 4, the current is expressed in the form of Equation 3 by Kirchhoff's law.

&Quot; (3) "

In addition, equation (4) is obtained by taking the resistance and the capacitor value into consideration in the entire circuit.

&Quot; (4) "

Here, the terminal voltage and the OCV can be expressed as a difference between the initial value (t = 0) and Equation (5).

&Quot; (5) "

이기 때문에 상기 수학식 5를 정리하면 수학식 6을 구할 수 있다.

The equation (6) can be obtained by summing up the equation (5).

&Quot; (6) "

Equation (7) can be obtained by differentiating Equation (6) with respect to time and summarizing it.

&Quot; (7) "

Laplace transform is transformed into the following equation (8).

&Quot; (8) "

라는 식을 세울 수 있으며, 이 식을 상기 수학식 8에 대입하면 수학식 9와 같이 표현될 수 있다.Here, assuming that the change amount of the current (I) is proportional to the OCV and the proportionality constant is h

And substituting this equation into Equation (8), it can be expressed as Equation (9). &Quot; (9) "

&Quot; (9) "

Here, each factor can be defined as shown in Equation (10).

&Quot; (10) "

The above-defined values are substituted into Equation (9) and summarized as Equation (11).

&Quot; (11) "

Equation (11) can be expressed in a matrix form as shown in Equation (12).

&Quot; (12) "

Here, the factors relating to the current and the voltage are obtained in the current measuring unit 10 and the voltage measuring unit 30, respectively, after a predetermined time interval. The parameters R _1, R _2, C, and h can be obtained by substituting the obtained current and voltage factors into Equation 12 and using an adaptive filter. A method of obtaining each parameter through the adaptive filter will be described later.

After obtaining the parameters through the adaptive filter, the basic equation for obtaining the OCV is substituted into the equation (13).

&Quot; (13) "

The battery equivalent circuit model is represented by a matrix form as shown in Equation (12).

를 w라고 하고,

를 θ라 하면 상기 수학식 12를 수학식 14와 같이 표현할 수 있다.In Equation (12)

Is w,

(12) can be expressed as Equation (14).

&Quot; (14) "

In this matrix, V ₂ and w can be known by passing the current measured by the current measuring unit 10 and the voltage measured by the voltage measuring unit 30 through a low-pass filter. The purpose of the adaptive filter is to obtain the θ matrix through these two values and to estimate the parameters in real time through each element of the θ matrix. Assuming that V ₂ passing through the low-pass filter is gV ₂ , Equation (14) can be expressed as Equation (15).

&Quot; (15) "

First, a parameter in an initial state where a terminal voltage is OCV is obtained because no current flows in the battery, and the parameter is substituted into Equation (15) to obtain an initial value of theta matrix. The matrix at this time is denoted by? O. If the square of this matrix is found, it can be expressed as shown in Equation (16).

&Quot; (16) "

Here, the K matrix required for the continuous updating of the &thetas; matrix can be defined as shown in Equation (17).

&Quot; (17) "

Here, R is a value determined to prevent the denominator from diverging to 0 due to the initial gV ₂ value, and the value is very small. This matrix can be expressed as shown in Equation (18).

&Quot; (18) "

Here, gV ₂ (n-1) may be referred to as a value following a phase of gV _2. The constant update of the &thetas; matrix occurs by a proportional relationship as shown in equation (19).

&Quot; (19) "

(20) can be obtained by summarizing Equation (19).

&Quot; (20) "

Here, since R is very small, the K matrix can be substituted and substituted. (21) " (21) "

&Quot; (21) "

Here, by substituting the basic relational expression, the expression (22) can be obtained.

&Quot; (22) "

In Equation (22), the θ value can be obtained through current data, voltage data, and a previous θ matrix. Therefore, it is possible to estimate each parameter continuously. After the initial stage, each of the θ matrix and the P matrix can be renewed to a newly obtained value. Thus, it is possible to constantly update the values of the parameters suitable for the battery equivalent circuit model. The OCV can be calculated from the parameters obtained here.

The SOCv calculation unit 70 calculates the SOCv using the OCV calculated by the OCV calculation unit 60. [ The SOCv calculating unit 70 may previously store the SOCv corresponding to the OCV as a lookup table (i.e., an OCV-SOCv lookup table). Accordingly, the SOCv calculation unit 70 can calculate the SOCv in the OCV calculated by the OCV calculation unit 60 through the OCV-SOCv look-up table.

The current correction coefficient update unit 80 calculates a coefficient for causing the SOCi calculated by the SOCi calculation unit 40 to coincide with the SOCv calculated by the SOCv calculation unit 70 and then outputs the coefficient to the current average value calculation unit 50 And the current correction coefficient corresponding to the temperature of the battery in the predetermined time interval is updated with the coefficient.

For example, when the SOCi calculated by the SOCi calculating unit 40 is 95% and the SOCv calculated by the SOCv calculating unit 70 is 93.1%, the current correction coefficient updating unit 80 updates the SOCi 95 %) To be consistent with SOCv (93.1%) can be calculated as 0.98. Here, when the average value of the current calculated in the predetermined time interval by the current average value calculation unit 50 is 0.5C-rate and the battery temperature in the predetermined interval is 15 ° C, the current correction coefficient update unit 80 ) Can update the recorded current correction coefficient 1 to 0.98 in accordance with the temperature of the battery corresponding to 15 ° C and the magnitude of the current in Table 1 is 0.5C-rate.

In the same manner, when the SOCi calculated by the SOCi calculating section 40 is 95% and the SOCv calculated by the SOCv calculating section 70 is 76%, the current correction coefficient updating section 80 A coefficient that allows SOCi (95%) to match SOCv (76%) can be calculated as 0.8. Here, when the average value of the currents calculated in the predetermined time interval by the current average value calculation unit 50 is -0.3C-rate and the battery temperature in the predetermined interval is -20 ° C, The controller 80 can update the current correction coefficient 1 recorded in correspondence to the battery temperature of -0.3C-rate and the temperature of the battery at -20 ° C in the above Table 1 to 0.8.

Table 3 below shows an exemplary result of the current correction coefficient update unit 80 updating the current correction coefficients recorded in Table 1 in the same manner as described above.

Battery temperature (℃) -30 -20 -10 0 15 25 50

C-rate



Discharge
-1.0 0.50 0.70 0.95 0.95 0.98 0.98 0.98 -0.5 0.65 0.80 0.95 0.95 0.98 1.00 1.00 -0.3 0.70 0.80 0.98 0.98 1.00 1.10 1.15
charge
0.3 0.70 0.80 0.98 0.98 1.00 1.10 1.15 0.5 0.65 0.80 0.95 0.95 0.98 1.10 1.00 1.0 0.50 0.70 0.95 0.95 0.98 0.98 0.98

As described above, the SOCi calculating unit 40, through the updating of the current correction coefficient of the current correction coefficient updating unit 80, obtains the current correction coefficient as shown in Table 3 from the current measuring unit 10 during the current accumulation in the battery And SOCi can be calculated by multiplying the product of the current correction coefficient and the magnitude of the obtained current. Since the SOCi at this time is calculated on the basis of the SOCv that is guaranteed to be accurate in the low current period, the measurement error and the quantization error of the current can be canceled at the time of SOCi calculation. Accordingly, the remaining capacity of the battery can be accurately It can be estimated.

5 is a flowchart of a method of calculating a current correction coefficient according to an embodiment of the present invention. Hereinafter, a current correction coefficient calculation method according to an embodiment of the present invention will be described with reference to FIG.

The current correction coefficient calculation method according to an embodiment of the present invention is such that the SOCi calculation unit 40 first obtains the current measured by the current measurement unit 10 and the temperature of the battery measured by the temperature measurement unit 20 SOCi is calculated by multiplying the current correction coefficient provided according to the magnitude of the current and the temperature of the battery with the magnitude of the obtained current, and multiplying the product of the current correction coefficient and the obtained magnitude of the current.

Next, the current average value calculation unit 50 acquires the current measured by the current measurement unit 10, and calculates an average value of the current in a predetermined time interval through the moving average filter (S200). Here, the predetermined time interval may be a time interval before the current measured by the current measuring unit 10 enters the low current interval.

Next, the OCV calculating unit 60 calculates the OCV by applying the current measured by the current measuring unit or the voltage measured by the voltage measuring unit to the battery equivalent circuit model after the predetermined time interval (S300 ).

Here, when the current measured by the current measuring unit has entered the low-current period after the predetermined time period, the OCV calculating unit 60 calculates the OCV of the current measured by the voltage measuring unit 60, The OCV can be calculated by applying the voltage measured by the battery 30 to the battery equivalent circuit model.

Alternatively, the OCV calculating unit 60 may calculate the current measured by the current measuring unit 10 and the voltage measured by the voltage measuring unit 30 after the predetermined time period, based on the battery equivalent circuit model and the adaptive filter To calculate the parameters used in the battery equivalent circuit model, and to calculate the OCV using the parameters.

Next, the SOCv calculating unit 70 calculates the SOCv using the OCV (S400). The SOCv calculating unit 70 may previously store the SOCv corresponding to the OCV as a lookup table (i.e., an OCV-SOCv lookup table). Accordingly, the SOCv calculation unit 70 can calculate the SOCv from the OCV calculated in S300 through the OCV-SOCv look-up table.

Next, the current correction coefficient update unit 80 calculates a coefficient to make SOCi calculated in S100 coincide with SOCv calculated in S400, and then calculates an average of the currents calculated in S200 and a current value The current correction coefficient corresponding to the temperature of the battery in step S500 is updated with the coefficient.

As described above, the current correction coefficient calculated by the present invention can be utilized to correct the magnitude of the current flowing in the battery when the current flowing in the battery is accumulated. Accordingly, the SOCi calculation can accurately estimate the remaining capacity of the battery. It does.

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, but, on the contrary, Of course, it is possible to modify it. Accordingly, it is intended that the technical scope of the present invention be defined only by the appended claims, and that all equivalent or equivalent variations thereof fall within the technical scope of the present invention.

10: current measuring unit 20: temperature measuring unit
30: voltage measuring unit 40: SOCi calculating unit
50: current average value calculation unit 60: OCV calculation unit
70: SOCv calculating unit 80: current correction coefficient updating unit

Claims (8)

A current measuring unit for measuring a current flowing in the battery;
A temperature measuring unit for measuring a temperature of the battery;
A voltage measuring unit for measuring a voltage across both ends of the battery;
Wherein the current measuring unit obtains a current measured by the current measuring unit and a temperature of the battery measured by the temperature measuring unit, multiplies the current correction coefficient provided according to the magnitude of the current and the temperature of the battery with the obtained magnitude of the current, An SOCi calculating unit for calculating a state of charge based on current (SOCi) by multiplying the product of the current correction coefficient and the obtained current magnitude;
A current average value calculation unit for obtaining a current measured by the current measurement unit and calculating an average value of the current in a predetermined time interval through a moving average filter;
An OCV calculating unit for calculating an OCV (Open Circuit Voltage) by applying a current measured by the current measuring unit or a voltage measured by the voltage measuring unit to the battery equivalent circuit model after the predetermined time interval;
An SOCv calculating unit for calculating a state of charge based on voltage (SOCv) using the OCV calculated by the OCV calculating unit; And
And a current correction coefficient updating unit updating a current correction coefficient corresponding to the battery temperature in the predetermined time interval with the average value of the current after calculating the coefficient to make the SOCi coincide with the SOCv A current correction coefficient calculation device for estimating a remaining capacity of a battery.
The method according to claim 1,
Wherein the preset time interval is a time interval before the current measured by the current measuring unit enters the low current interval.
The method according to claim 1,
The OCV calculator may measure the current measured by the current measuring unit after the preset time interval by the voltage measuring unit after a predetermined time at the time of entering the low current interval And the OCV is calculated by applying only the voltage to the battery equivalent circuit model.
The method according to claim 1,
The OCV calculation unit may apply the current measured by the current measuring unit and the voltage measured by the voltage measuring unit to the battery equivalent circuit model and the adaptive filter after the preset time interval and use the battery equivalent circuit model And calculating the OCV using the parameter. A current correction coefficient calculating apparatus for estimating a remaining capacity of a battery.
A current measuring unit for measuring a current flowing through the battery; a current measuring unit for measuring a current flowing through the battery; Calculating a SOCi by multiplying a product of a correction coefficient and a magnitude of the obtained current;
Obtaining a current measured by the current measuring unit and calculating an average value of the current in a predetermined time interval through a moving average filter;
Calculating an OCV by applying a current measured by the current measuring unit or a voltage measured by the voltage measuring unit to the battery equivalent circuit model after the predetermined time period;
Calculating SOCv using the OCV; And
Calculating a coefficient for matching the SOCi with the SOCv and updating a current correction coefficient corresponding to an average value of the current and a temperature of the battery in the predetermined time interval with the coefficient; Calculating a current correction coefficient for capacity estimation.
6. The method of claim 5,
Wherein the predetermined time period is a time period before the current measured by the current measuring unit enters the low current period.
6. The method of claim 5,
The step of calculating the OCV may further include the steps of: when the current measured by the current measuring unit is in the low current period after the predetermined time period, Wherein the OCV is calculated by applying only the voltage measured by the OCV to the battery equivalent circuit model.
6. The method of claim 5,
The calculating of the OCV may include applying a current measured by the current measuring unit and a voltage measured by the voltage measuring unit to the battery equivalent circuit model and the adaptive filter after the predetermined time interval, Calculating a parameter used for the model, and calculating the OCV using the parameter.

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