KR101782527B1 - Method for estimating state-of-charge of battery rack and apparatus thereof - Google Patents

Abstract

The present invention prelates to a device for estimating a charging state of a battery rack including a battery pack composed of a unit battery. The device for estimating a charging state of a battery rack comprises: an input part receiving charging/discharging voltage data with respect to the unit battery; an imbalance measuring part calculating battery pack imbalance information including a value of an imbalance degree with respect to charging/discharging voltage of the battery pack from the charging/discharging voltage data; and a charging state estimating part calculating battery pack charging state information including a value of the charging state with respect to the battery pack from the charging/discharging voltage data, and estimating a value of a battery rack charging state representing a degree of the charging state with respect to the battery rack based on the battery pack charging state information and the battery pack imbalance information.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a battery rack charging state estimating apparatus,

The present invention relates to a technique for estimating a state of charge of a battery, and more particularly, to an apparatus and method for estimating a state of charge of a battery rack including a plurality of battery packs.

In order to build high voltage and high capacity applications such as Electric Vehicle (EV) and Energy Storage System (ESS), serial, parallel and serial / parallel combinations of lithium battery cells are required. This is called a battery pack (battery pack or battery tray).

Like the unit battery, a battery management system (BMS: Battery Management System) is essential for stable operation of the battery pack. In such a battery management system, precise measurement of the state of charge (SOC) of the battery pack and balance of voltage and charge state of the cells inside the battery pack are required.

Battery Pack Charged State In terms of precise measurement, an algorithm for estimating the state of charge of a battery pack is essential. If the state of charge of the battery pack is correctly checked by the estimation algorithm, it is possible to avoid the degradation of lifetime due to over-charge and over-discharge.

In view of the voltage and charge state balance of the cells inside the battery pack, a screening technique, a unit cell discrimination technique and a balancing technique are currently applied in which a cell having a uniform electrochemical characteristic is selected in advance and a battery pack is constructed. However, the unit cell discrimination technique is costly and time consuming, and the balancing technique has disadvantages in that the circuit design requires an additional cost. Because of these disadvantages, most battery pack manufacturers actually implement unit cell identification techniques simply and minimize balancing techniques.

In this situation, in the case of an energy storage system in which a battery rack composed of a plurality of battery packs is used, a technique for measuring the state of charge of the battery rack is further required. Generally, the energy storage system may be a battery pack based on a serial and parallel combination of unit batteries, and the battery rack in which the battery pack is extended.

In order to estimate the total charging state of the battery rack, a technique of estimating the charging state of the battery rack from an average value of charging states of the battery pack has been used. In detail, monitoring of the voltage of the unit battery is required in order to estimate the heavy state of the battery pack. Similarly, the state of charge of the battery rack can be attributed to the state of charge of the battery pack. In an ideal case, the estimation of the state of charge of the battery pack may be based on an average value of the state of charge of the monitored battery, and an estimation of state of charge of the battery rack may be obtained from an average value of the state of charge of the battery pack. However, the different electrochemical characteristics between the batteries constituting the battery pack and the internal voltage imbalance due to the long-time charging and discharging are inevitable, and the voltage imbalance leads to an error in estimating the state of charge of the battery rack. Therefore, in order to ensure the accuracy of battery rack charging state estimation, there is a demand for battery rack charging state estimation technology considering the internal voltage unbalance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a battery pack charging state estimation method and apparatus based on unbalance information on a battery pack charging state.

It is another object of the present invention to provide a battery rack charged state estimation method and apparatus for estimating a charged state of a battery rack by reflecting an unbalance degree of each battery pack which constitutes a battery rack.

In order to achieve the above object, in one aspect, the present invention provides an apparatus for estimating a state of charge of a battery rack including a battery pack composed of unit batteries, the apparatus comprising: An input unit; An unbalance measuring unit for calculating battery pack unbalance information including a value of an unbalance degree with respect to a charge / discharge voltage of the battery pack from the charge / discharge voltage data; And a controller for calculating battery pack charge state information including a charge state value for the battery pack from the charge / discharge voltage data, and calculating a charge state of the battery pack based on the battery pack charge state information and battery pack unbalance information, And a battery state estimation unit for estimating a battery state of the battery pack.

According to another aspect of the present invention, there is provided a method of estimating a charged state of a battery rack including a battery pack, the method comprising: receiving charging / discharging voltage data for the unit battery; Calculating battery pack charge state information including a charge state value for the battery pack from the charge / discharge voltage data; Calculating battery pack imbalance information including a value of an unbalance degree for the battery pack from the charge / discharge voltage data; And estimating a battery pack charging state value indicating a charging state of the battery pack based on the battery pack charging state information and the battery pack unbalance information, .

The present invention has an effect of providing a more precise battery pack state estimation value in consideration of the degree of unbalance of the battery pack.

Further, the present invention has an effect of providing a highly reliable battery rack charged state estimation value by considering the degree of unbalance of each battery pack which is different from each other.

1 is a diagram showing a configuration of a battery rack charged state estimation system according to an embodiment.
2 is a diagram showing a detailed configuration of a battery rack charged state estimation apparatus according to an embodiment.
FIG. 3 is a diagram illustrating charging / discharging of a battery pack according to an embodiment of the present invention.
4 is a diagram illustrating a waveform diagram of a current profile for charge / discharge current according to an embodiment.
FIG. 5 is a diagram illustrating a wavelet transform process according to an exemplary embodiment. Referring to FIG.
6 is a diagram illustrating a frequency band of wavelet component values according to an exemplary embodiment.
7 is a flowchart illustrating a method of estimating a charged state of a battery pack according to an embodiment.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference numerals whenever possible, even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected to or connected to the other component, It should be understood that an element may be "connected," "coupled," or "connected."

1 is a diagram showing a configuration of a battery rack charged state estimation system according to an embodiment.

Referring to FIG. 1, the battery rack charging state estimation system may include a battery rack 11 and a battery rack charging state estimation apparatus 100.

The battery rack 11 includes a plurality of battery packs 11-1-1, 11-1-2, ..., 11-1-n, 11-2-1, ..., 11-2-n,. ..., 11-nn. The battery rack 11 may be an aggregate of battery packs composed of a plurality of batteries. The battery or the battery pack may be used alone depending on the required electric capacity. However, in the energy storage system, which is a large-capacity system, a battery rack composed of a plurality of battery packs may be used. The battery packs 11-1-1, 11-1-2, ..., 11-1-n, 11-2-1, ..., 11-2-n, And may include a plurality of batteries internally. 1, the battery rack 11 includes nn battery packs 11-1-1, 11-1-2, ..., 11-1-n, 11-2-1, 2-n, ..., 11-nn. , 11-nn, 11-2-1, ..., 11-2-n, ..., 11-nn, the battery packs 11-1-1, 11-1-2, 1-a, 1-d, 2-1-a, ..., nnd may be included internally in the battery pack.

The battery rack charged state estimation apparatus 100 can estimate the state of charge of the battery rack 11 as a whole. The battery rack charge state estimation apparatus 100 may internally include an input unit 110, an unbalance measurement unit 120, a charge state estimation unit 130, and the like

The input unit 110 receives charge and discharge voltage data for the batteries 1-1-a, 1-1-b, 1-1-c, 1-1-d, 2-1-a, Input can be received. The charge / discharge voltage data is measured from the batteries (1-1-a, 1-1-b, 1-1-c, 1-1-d, 2-1-a, Lt; / RTI > 1, the charging / discharging voltage data (V _{1-1 -a} , V _2-1-a , V _n -1) of the three batteries (1-1- _-1-a ) is input to the input unit 110 as an example. The charging / discharging voltage data is stored in the battery packs 11-1-1, 11-1-2, ..., 11-1-n, 11-2-1, n, ..., 11-nn. 1-a, 1-1-d, 2-1-a, ..., nnd or battery packs 11-1-1 , 11-1-2, ..., 11-1-n, 11-2-1, ..., 11-2-n, ..., 11-nn are used . In this embodiment, the charge / discharge voltage data measured from the batteries 1-1-a, 1-1-b, 1-1-c, 1-1-d and 2-1- Can be used. The charge / discharge voltage data is transmitted to the unbalance measuring unit 120 and the charge state estimating unit 130, respectively, and can be processed to calculate a battery rack charge state estimation value.

The unbalance measuring unit 120 measures the battery packs 11-1-1, 11-1-2, ..., 11-1-n, 11-2-1, ..., 11 -2-n, ..., 11-nn) of the battery pack unbalance information.

The battery pack unbalance information is stored in the battery packs 11-1-1, 11-1-2, ..., 11-1-n, 11-2-1, ..., 11-2-n, Discharge voltage imbalance between the batteries (1-1-a, 1-1-b, 1-1-c, 1-1-d and 2-1- Lt; / RTI > The charging and discharging voltages of the batteries 1-1-a, 1-1-b, 1-1-c, 1-1-d and 2-1-a to nnd have electrochemical characteristics and long charge / 11-2, ..., 11-1-n, 11-2-1, ..., 11-2, ..., 11-2, -n, ..., 11-nn, as well as the charge / discharge voltage for the battery rack 11 can be made non-uniform. Therefore, in order to accurately estimate the charging state value of the battery rack 11, the batteries 1-1-a, 1-1-b, 1-1-c, 1-1-d, ., 11-n, 11-2-1, ..., 11-2-n, , ..., 11-nn) should be taken into account. Here, the battery packs 11-1-1, 11-1-2, ..., 11-1-n, 11-2-1, ..., 11-2-n, ) An imbalance in the state of charge will be taken into account. The battery pack unbalance information may further include coefficient information included in an algorithm for a battery rack charging state value. The battery pack unbalance information can be reflected as a coefficient in the calculation of the battery rack charging state value through the following equation (1).

The charging state estimating unit 130 calculates the battery pack unbalance information based on the battery pack unbalance information stored in the unit batteries 1-1 to 1-16, 1-1 to 1-16, 1-1 to 1-16, 1-1 to 1- ..., nnd) is required. Here, the battery packs 11-1-1, 11-1-2, ..., 11-1-n, 11-2-1, ..., 11-2-n, May be configured in serial or parallel combination of batteries 1-1-a, 1-1-b, 1-1-c, 1-1-d, 2-1-a, , The voltage imbalance due to the parallel combination batteries is insignificant compared with the voltage imbalance caused by the series combination batteries. Therefore, the charge state estimation unit 130 can monitor only the voltage imbalance caused by the batteries in the series combination in order to calculate the battery pack imbalance information. Monitoring the voltage imbalance across all the batteries can cause problems that increase the requirements of the battery management system that manages the battery. Therefore, the charge state estimating unit 130 can monitor the voltage imbalance only for the series-connected batteries, thereby efficiently managing the battery management system. For reasons such as the reason for monitoring the series combination battery, the charge state estimating unit 130 may monitor only the voltage imbalance caused by the battery packs of the series combination in order to estimate the battery pack charge state value.

The charge state estimation unit 130 may calculate battery pack state information from the charge / discharge voltage data, and may estimate the battery pack state value based on the battery pack state information and the battery pack unbalance information.

The battery pack charging status information is stored in the battery packs 11-1-1, 11-1-2, ..., 11-1-n, 11-2-1, ..., 11-2-n, , 11-nn, respectively. The battery packs 11-1-1, 11-1-2, ..., 11-1-n, 11-2-1, ..., 11-2-n, May be computed using current integration and electrical equivalent circuit model based adaptive control (e.g., extended Kalman filter control or sliding mode control).

The battery pack charging state values are stored in the battery packs 11-1-1, 11-1-2, ..., 11-1-n, 11-2-1, ..., 11-2-n, , And 11-nn, respectively. The charging state estimating unit 130 can estimate the state of charge of the battery rack using the following equation (1).

수식 (1)

Equation (1)

Here, the battery rack 11 includes x battery packs, SOCrack is a battery rack charging state value for the battery rack 11 including x battery packs, and SOC1tray, SOC2tray, SOC3tray, ... , SOCxtray is a value of the charge state for each of the x battery packs, and coefficients a1, a2, a3, ..., ax can satisfy a1 + a2 + a3 + ... + ax =

For example, when the battery rack 11 is composed of five battery packs, the charge state value of the battery rack 11 may be as follows.

The SOC1tray, SOC2tray, SOC3tray, SOC4tray, and SOC5tray are values of the battery pack charging state of the battery rack 11 composed of five battery packs, and the unbalance information of each battery pack is reflected The coefficients a1, a2, a3, a4 and a5 can satisfy a1 + a2 + a3 + a4 + a5 = 1.

The charge state value of the barrier track can be obtained from the battery pack charge state value. In detail, in an ideal case, the battery pack charge state value may be obtained from an average of battery charge state values, and the battery rack charge state value may be obtained from an average of the battery pack charge state values. However, the battery packs 11-1-1, 11-1-2, ..., 11-1-n, 11-2-1, ..., 11-2-n, The voltage imbalance between the batteries 1-1-a, 1-1-b, 1-1-c, 1-1-d and 2-1-a, The battery pack imbalance degree must be taken into consideration in order to obtain the battery rack charging state value. The degree of imbalance for the battery pack can be reflected as a coefficient in the above equation (1). In particular, the coefficients are information on battery pack unbalance information, that is, the battery packs 11-1-1, 11-1-2, ..., 11-1-n, 11-2-1, 2-n, ..., 11-nn, respectively. Preferably, the larger the imbalance of the internal voltage of a specific battery pack is, the smaller the value of the coefficient is, and the smaller the imbalance of the internal voltage of a particular battery pack, the larger the value of the coefficient.

2 is a diagram showing a detailed configuration of a battery rack charged state estimation apparatus according to an embodiment.

2, the charging state estimation unit 130 of the battery pack state estimation apparatus 100 may further include a battery pack state estimation unit 131 and a battery rack state estimation unit 132.

The battery pack charge state estimating unit 131 estimates the state of charge of the battery packs 11-1-1, 11-1-2, ..., 11-1-n, 11-2-1, , ..., 11-nn) can be calculated. The battery pack charge state estimating unit 131 may calculate the battery pack charge state value using the current integration method and the electric equivalent circuit model based adaptive control algorithm.

The battery rack charging state estimating unit 132 can calculate the charging state value for the battery rack 11. [ In detail, the battery pack charging state estimating unit 132 receives the battery pack unbalance information from the unbalance measuring unit 120 and the battery pack charging state information from the battery pack charging state estimating unit 131, respectively. The battery pack charge state estimating unit 132 converts the battery pack imbalance information into a coefficient for the equation (1), and applies the battery pack charge state value included in the battery pack charge state information to the equation (1) So that the final battery rack charging state value can be calculated.

FIG. 3 is a diagram illustrating charging / discharging of a battery pack according to an embodiment of the present invention.

Referring to FIG. 3, the apparatus for estimating the state of charge of a battery rack 100 may further include a charging unit 140. 1-1-b, 1-1-c, 1-1-d, 2-1-a, ..., nnd in order to estimate the state of charge of the battery rack 11, Charge / discharge voltage data can be obtained. The charging and discharging voltage data for the batteries 1-1-a, 1-1-b, 1-1-c, 1-1-d, 2-1-a, And the battery pack charge state value.

In order to obtain the charge / discharge voltage data for the batteries 1-1-a, 1-1-b, 1-1-c, 1-1-d and 2-1- A power supply is required, and the charging unit 140 serves to supply power.

At this time, the current flowing to each battery 1-1-a, 1-1-b, 1-1-c, 1-1-d, 2-1- Can be determined according to the profile. 3, the currents I _{1-1 -a} and I _{2-1 -a} flowing to the three batteries 1-1-a and 2-1-a and n-1-a through the charging and discharging unit 140, _-a , I _n-1-a ) are shown as an example.

4 is a diagram illustrating a waveform diagram of a current profile for charge / discharge current according to an embodiment.

The charging unit 140 is connected to the batteries 1-1-a, 1-1-b, 1-1-c, and 1-b using the current profiles in which the charging and discharging current values vary at a plurality of levels, -1-d, 2-1-a, ..., nnd can be charged and discharged.

In the current profile, the charge-discharge time may be shorter than the time required to fully discharge the full-charge cell. The discharge capacity of the battery can be expressed in terms of the time required to blow up to the rated discharge current (C-rate). For example, when the battery is discharged for 1 hour at the rated discharge current of 1A, the discharge capacity of the battery that is in the full state can be indicated as 1C. As another example, when the battery is discharged for 2 hours at a rated discharge current of 0.5 A, the discharge capacity of the battery that is in the full state can be indicated by 2C.

In the current profile, the charge-discharge time may be shorter than the time required to discharge the full-charged cell to such a rated discharge current to fully discharge the cell. Normally, to check the discharge capacity of a battery, it is necessary to measure the time while the battery is fully charged and discharged again.

The charge state estimation unit 130 may use a wavelet transform to estimate the state of charge of the battery pack.

The charge state estimation unit 130 may calculate the state of charge of the battery pack using the current integration method or the adaptive control based on the equivalent circuit model. When the charge state estimating unit 130 uses the adaptive control based on the equivalent circuit model, the charge state estimating unit 130 estimates the state of charge of the battery packs 11-1-1, 11-1-2, -n, 11-2-1, ..., 11-2-n, ..., 11-nn can be calculated using the wavelet transform.

The wavelet transform is a method of decomposing an original signal, if any, into a low frequency (approximation, Am) and a high frequency (detail, Dm) component.

The charge state estimation unit 130 may receive charge / discharge voltage data from the input unit 110. [

The charge state estimation unit 130 calculates the charge state of the batteries 1-1-a, 1-1-b, 1-1-c, 1-1-d, 2-1-a, Signal and decompose it into a low-frequency voltage component and a high-frequency voltage component using a multi-resolution analysis (MRA) method of wavelet transform. Here, the wavelet transform may be basically a discrete wavelet transform. The discrete wavelet transform uses one input. In other words, the voltage of one unit cell is regarded as the original signal, and it is decomposed into low frequency and high frequency voltage components through resolution analysis. However, if one input is applied and the next input is repeated, there is a disadvantage that the data acquisition time for obtaining the battery pack charging state value is excessive. Accordingly, the battery packs 11-1-1, 11-1-2, ..., 11-1-n, 11-2-1, ..., 11-2- n-1, n-1, n-2, n-1, ) May be simultaneously applied as an input, and a multivariate wavelet transform (MWT) technique for decomposing the voltages into low frequency and high frequency voltage components may be used.

FIG. 5 is a diagram illustrating a wavelet transform process according to an exemplary embodiment. Referring to FIG.

Referring to FIG. 5, the charge state estimating unit 130 estimates the state of charge of the batteries 1-1-a, 1-1-b, 1-1-c, 1-1-d, 2-1- nnd) to generate an input variable X. The input variable X is generated by subtracting the voltage value from the voltage data. The charge state estimation unit 130 estimates the state of charge of each battery 1-1-a, 1-1-b, 1-1-c, 1-1-d, 2-1-a,. sampled input variables (X _{1-1 -a} , X _{1-1 -b} , X _{1-1 -c} , X _{1-1 -d} , X _2-1-a , ..., nnd) ., X _nnd , < / RTI >

The charging state estimating unit 130 estimates the state of charge of each battery 1-1-a, 1-1-b, 1-1-c, 1-1-d, and 2-1-a using an MRA (Multi-Resolution Analysis) , ..., nnd) of the wavelet components. In FIG. 5, it is exemplarily shown that the wavelet transformation proceeds to five steps.

The charge state estimating unit 130 generates the low frequency wavelet component value A1 and the high frequency wavelet component value D1 through the wavelet transform of the input variable X in a first step. Then, the charge state estimation unit 130 again generates a low-frequency wavelet component value A2 and a high-frequency wavelet component value D2 by performing wavelet transformation on A1 in the second step. In this way, the charge state estimation unit 130 sequentially performs the third, fourth, and fifth steps of wavelet transform to generate low-frequency wavelet component values A1 to A5 and high-frequency wavelet component values D1 to D5. In this case, since the wavelet transform is performed using the low-frequency wavelet component values of the previous stage in each of the two or more stages, the final low-frequency wavelet component value (for example, A5) and the high- For example, D1 to D5.

6 is a diagram illustrating a frequency band of wavelet component values according to an exemplary embodiment.

Referring to FIG. 6, the charge state estimation unit 130 generates a low frequency wavelet component Am and high frequency wavelet component values D1 to Dm through M (M is a natural number of 2 or more) wavelet transform steps. At this time, the low-frequency wavelet component value Am generated in the M-th stage is located in the lowest frequency band, and the high-frequency wavelet component value Dm generated in the M-th stage is positioned in the next lowest frequency band.

Then, the charge state estimation unit 130 calculates the state of charge of each battery 1-1-a, 1-1-b, 1-1-c, and 1-12 from the generated wavelet component values (for example, A5 and D1- 1-1-d, 2-1-a, ..., nnd) of the equivalent circuit model.

The charge state estimation unit 130 calculates the state of charge of each battery 1-1-a, 1-1-b, 1-1-c, 1-1-d, 2-1- ..., nnd can be estimated.

The charge state estimation unit 130 estimates the state of charge of each battery 1-1-a, 1-1-b, 1-1-c, 1-1-d, 2-1- A battery pack (1-a, 1-1-b, 1-1-c, 1-1-d and 2-1-a, 11-2-1, 11-1-2, ..., 11-1-n, 11-2-1, ..., 11-2-n, ..., 11- The state value can be estimated. The statistical analysis is performed on the basis of the average of the charge state values for the batteries 1-1-a, 1-1-b, 1-1-c, 1-1-d, Standard deviation, and the like.

The charge state estimation unit 130 estimates the state of charge of the battery pack 11-1-1, 11-1-2, ..., 11-1-n, 11-2-1, ..., 11-2-n,. 11-1-n, 11-2-1, ..., 11-nn from the charge state values for the battery packs 11-1-1, 11-1-2, 2-n, ..., 11-nn of the battery pack 11,

7 is a flowchart illustrating a method of estimating a charged state of a battery pack according to an embodiment.

Referring to FIG. 7, the input unit 110 of the battery rack estimating apparatus 100 includes batteries 1-1-a, 1-1-b, 1-1-c, 1-1-d, a,..., nnd can be charged / discharged with respect to each battery charged / discharged with a predetermined current profile (S702).

11-1-2, ..., 11-1-n, 11-2-1, ..., 11-2, ..., 11-2, ..., 11-2, ..., 11-2, ..., 11-2, ..., ..., 11-2-n, ..., 11-nn (S704).

11-1-2, ..., 11-1-n, 11-2-1, ..., 11-2, ..., 11-2, ..., 11-2, ..., 11-2, ..., 11-2, ..., ..., 11-2-n, ..., 11-nn (S706).

The charge state estimating unit 130 may estimate a battery pack charge state value indicating a charge state of the battery pack 11 based on the battery pack charge state information and the battery pack unbalance information at step S708.

It is to be understood that the terms "comprises", "comprising", or "having" as used in the foregoing description mean that the constituent element can be implanted unless specifically stated to the contrary, But should be construed as further including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (14)

An apparatus for estimating a state of charge of a battery rack including battery packs composed of unit batteries,
An input unit for receiving charge / discharge voltage data for the unit batteries;
An unbalance measuring unit for calculating battery pack unbalance information including a value of an unbalance degree with respect to a charging / discharging voltage of the battery packs from the charging / discharging voltage data; And
Calculating charge state information of the battery pack including the state of charge of the battery pack with respect to the battery packs from the charge / discharge voltage data, calculating charge state information of the battery pack based on the battery pack charge state information and the battery pack imbalance information, And a charge state estimation unit for estimating a charge state value of the battery rack,
The battery rack charge state value is defined as follows,

A2, a3, ..., an is a1 + a2 + a2, a3, ..., an, a3 + ... + an = 1),
Wherein the coefficient is determined by the battery pack imbalance information,
Wherein the coefficient is larger as the value of the unbalance degree of the battery pack unbalance information is smaller and smaller as the value of the unbalance degree of the battery pack unbalance information is larger,
Wherein the battery pack imbalance information is calculated only for the battery packs in which the unit batteries are combined in series. delete delete delete delete delete delete A method for estimating a state of charge of a battery rack including battery packs composed of unit batteries,
Receiving charging / discharging voltage data for the unit batteries;
Calculating battery pack charging state information including a battery pack charging state value for the battery packs from the charging / discharging voltage data;
Calculating battery pack unbalance information including a value of an unbalance degree of a charge / discharge voltage of the battery packs from the charge / discharge voltage data; And
Estimating a battery rack charging state value indicating a charging state of the battery rack based on the battery pack charging state information and the battery pack unbalance information,
The battery rack charge state value is defined as follows,

A2, a3, ..., an is a1 + a2 + a2, a3, ..., an, a3 + ... + an = 1),
Wherein the coefficient is determined by the battery pack imbalance information,
Wherein the coefficient is larger as the value of the unbalance degree of the battery pack unbalance information is smaller and smaller as the value of the unbalance degree of the battery pack unbalance information is larger,
Wherein the battery pack imbalance information is calculated only for the battery packs in which the unit batteries are combined in series. delete delete delete delete delete delete

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