Patent Description:
The described technology relates to a battery apparatus and a method for measuring a cell voltage.

An electric vehicle or a hybrid vehicle is a vehicle that obtains power by driving a motor mainly using a battery as a power supply. The electric vehicles are being actively researched because they are alternatives that can solve pollution and energy problems of internal combustion vehicles. Rechargeable batteries are used in various external apparatuses other than the electric vehicles.

Recently, as a battery having a high output and a large charging capacity is required, a battery pack in which a plurality of battery modules are connected in series is used. Since each battery module includes a plurality of battery cells, it is required to measure a voltage of the battery cell in order to diagnose the battery.

An integrated circuit (IC)-type cell voltage sensing circuit is used to measure the voltage of the battery cell. Currently, a separate cell voltage sensing IC is connected to each battery module. For example, one or more cell voltage sensing ICs are connected to one battery module, and one or more separate cell voltage sensing ICs are connected to another battery module. Accordingly, as the number of battery modules included in the battery pack increases, the number of required cell voltage sensing ICs increases, and thus the cost of the battery may increase.

<CIT> relates to a battery monitor apparatus to monitor states (voltages and the like) of respective unit batteries in a battery pack that has multiple battery modules connected by conductive members such as bus bars, and each battery module includes some of the unit batteries connected in series.

In some embodiments, a battery apparatus and a method for measuring a cell voltage for optimizing a cell voltage sensing circuit may be provided.

The present invention is defined by independent claims. Preferred embodiments are given by the subject-matter of dependent claims.

According to an embodiment, a battery apparatus may be provided. The battery apparatus may include a first battery module including a plurality of battery cells, a second battery module including a plurality of battery cells, a bus-bar connecting a first electrode terminal of the first battery module and a second electrode terminal of the second battery module, a cell voltage sensing circuit, and a processor. The cell voltage sensing circuit may be shared by at least some battery cells of the first battery module and at least some battery cells of the second battery module, and may measure a voltage of each battery cell and a voltage of the bus-bar. The processor may correct a voltage of at least one battery cell among the some battery cells of the first battery module and the some battery cells of the second battery module based on the voltage of the bus-bar.

In some embodiments, the processor may correct the voltage of the at least one battery cell by subtracting the voltage of the bus-bar from the voltage of the at least one battery cell measured by the cell voltage sensing circuit.

In some embodiments, the first electrode terminal may be a negative terminal of the first battery module, and the at least one battery cell may include a battery cell connected to the negative terminal among the plurality of battery cells of the first battery module.

In some embodiments, the second electrode terminal may be a positive terminal of the second battery module, and the at least one battery cell may include a battery cell connected to the positive terminal among the plurality of battery cells of the second battery module.

In some embodiments, the cell voltage sensing circuit may be provided in a form of an integrated circuit (IC) having a plurality of pins. The plurality of battery cells of the first battery module may include a first battery cell connected to the first electrode terminal, and the plurality of battery cells of the second battery module may include a second battery cell connected to the second electrode terminal. In this case, a contact between the first electrode terminal and the first battery cell and a contact between the second electrode terminal and the second battery cell may be respectively connected to a first pin and a second pin for the bus-bar among the plurality of pins. A contact between the second electrode terminal and the second battery cell may be connected to a pin for battery cell voltage sensing among the plurality of pins.

In some embodiments, the at least one battery cell may include the first battery cell.

In some embodiments, the first electrode terminal may be a negative terminal of the first battery module, and the second electrode terminal may be a positive terminal of the second battery module. In this case, a contact between the first electrode terminal and the first battery cell may be a negative electrode of the first battery cell, and a contact between the second electrode terminal and the second battery cell may be a positive electrode of the second battery cell.

In some embodiments, the first electrode terminal may be a positive terminal of the first battery module, and the second electrode terminal may be a negative terminal of the second battery module. In this case, a contact between the first electrode terminal and the first battery cell may be a positive electrode of the first battery cell, and a contact between the second electrode terminal and the second battery cell may be a negative electrode of the second battery cell.

According to another embodiment, a method of measuring a cell voltage of a battery apparatus including a first battery module and a second battery module may be provided. The method may include measuring a voltage of each battery cell using a cell voltage sensing circuit shared by at least some battery cells of the first battery module and at least some battery cells of the second battery module, measuring a voltage of a bus-bar connecting the first battery module and the second battery module using the cell voltage sensing circuit, and correcting a voltage of at least one battery cell among the some battery cells of the first battery module and the some battery cells of the second battery module based on the voltage of the bus-bar.

In some embodiments, the correcting the voltage of the at least one battery cell may include correcting the voltage of the at least one battery cell by subtracting the voltage of the bus-bar from the voltage of the at least one battery cell measured by the cell voltage sensing circuit.

In some embodiments, the at least one battery cell may include a battery cell connected to the bus-bar among the some battery cells of the first battery module or a battery cell connected to the bus-bar among the some battery cells of the second battery module.

According to yet another embodiment, a battery apparatus may be provided. The battery apparatus may include a plurality of battery modules including a first battery module and a second battery module, a bus-bar connecting the first battery module and the second battery module, and a cell voltage sensing IC shared by a plurality of battery cells of the first battery modules and a plurality of battery cells of the second battery module and configured to measure a voltage of each battery cell.

In some embodiments, the cell voltage sensing IC may have a plurality of pins. A negative electrode of a first battery cell connected to the bus-bar among the plurality of battery cells of the first battery module and a positive electrode of a second battery cell connected to the bus-bar among the plurality of battery cells of the second battery module may be respectively connected to a first pin and a second pin for the bus-bar among the plurality of pins. A positive electrode of the first battery cell and the positive electrode of the second battery cell may be respectively connected to a third pin and a fourth pin for battery cell voltage sensing among the plurality of pins.

In this case, the processor may measure a voltage of the first battery cell by correcting a voltage between the third pin and the fourth pin based on a voltage between the first pin and the second pin.

In some embodiments, the cell voltage sensing IC may have a plurality of pins. A negative electrode of a first battery cell connected to the bus-bar among the plurality of battery cells of the first battery module and a positive electrode of a second battery cell connected to the bus-bar among the plurality of battery cells of the second battery module may be respectively connected to a first pin and a second pin for the bus-bar among the plurality of pins. The negative electrode of the first battery cell and a negative electrode of the second battery cell may be respectively connected to a third pin and a fourth pin for battery cell voltage sensing among the plurality of pins.

In this case, the processor may measure a voltage of the second battery cell by correcting a voltage between the third pin and the fourth pin based on a voltage between the first pin and the second pin.

In some embodiments, the plurality of battery cells of the second battery module may be some battery cells of the second battery module, and the plurality of battery modules may further include a third battery module. In this case, the battery apparatus may further include a second bus-bar connecting the second battery module and the third battery module, and a second cell voltage sensing IC shared by remaining battery cells of the second battery module and a plurality of battery cells of the third battery module.

According to some embodiments, the number of cell voltage sensing circuits connected to the plurality of battery modules may be reduced. According to another embodiment, the voltage of the bus-bar included in the measured voltage of the battery cell may be compensated.

In the following detailed description, only certain embodiments have been shown and described, simply by way of illustration. As those skilled in the art would realize, the described embodiments may be modified in various different ways. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.

When it is described that an element is "connected" to another element, it should be understood that the element may be directly connected to the other element or connected to the other element through a third element. On the other hand, when it is described that an element is "directly connected" to another element, it should be understood that the element is connected to the other element through no third element.

As used herein, a singular form may be intended to include a plural form as well, unless the explicit expression such as "one" or "single" is used.

In flowcharts described with reference to the drawings, the order of operations or steps may be changed, several operations or steps may be merged, a certain operation or step may be divided, and a specific operation or step may not be performed.

<FIG> is a diagram showing a battery apparatus according to an embodiment.

Referring to <FIG>, a battery apparatus <NUM> has a structure that can be electrically connected to an external apparatus <NUM> through a positive link terminal DC(+) and a negative link terminal DC(-). In some embodiments, the battery apparatus <NUM> may be connected to the external apparatus <NUM> through the positive link terminal DC(+) and the negative link terminal DC(-). When the external apparatus is a load, the battery apparatus <NUM> is discharged by operating as a power supply that supplies power to the load. The external apparatus operating as the load may be, for example, an electronic device, a mobility apparatus, or an energy storage system (ESS). The mobility apparatus may be, for example, a vehicle such as an electric vehicle, a hybrid vehicle, or a smart mobility.

The battery apparatus <NUM> includes a battery pack <NUM>, a positive main switch <NUM>, a negative main switch <NUM>, a cell voltage sensing circuit <NUM>, and a processor <NUM>.

The battery pack <NUM> has a positive terminal PV(+) and a negative terminal PV(-). The battery pack includes a plurality of battery modules (not shown) connected in series between the positive terminal PV(+) and the negative terminal PV(-), and each battery module includes a plurality of battery cells (not shown). In some embodiments, the plurality of battery cells in each battery module may be connected in series. In some embodiments, the battery cell may be a rechargeable cell. In this way, the plurality of battery modules may be connected in the battery pack <NUM> to supply desired power.

The positive main switch <NUM> is connected between the positive terminal PV(+) of the battery pack <NUM> and the positive link terminal DC(+) of the battery apparatus <NUM>. The negative main switch <NUM> is connected between the negative terminal PV(-) of the battery pack <NUM> and the negative link terminal DC(-) of the battery apparatus <NUM>. The switches <NUM> and <NUM> may be controlled by the processor <NUM> to control an electrical connection between the battery pack <NUM> and the external apparatus. That is, the switches <NUM> and <NUM> may control supply of a current of the battery pack <NUM>. In one embodiment, each of the switches <NUM> and <NUM> may be a contactor implemented in a relay. In another embodiment, each of the switches <NUM> and <NUM> may be an electrical switch such as a transistor. In some embodiments, the battery apparatus <NUM> may further include driving circuits (not shown) for controlling the switches <NUM> and <NUM>, respectively.

The cell voltage sensing circuit <NUM> measures voltages of battery cells of the battery pack <NUM>. In some embodiments, the cell voltage sensing circuit <NUM> may measure the voltage of the battery cell by sensing voltages at positive and negative electrodes of the battery cell. The processor <NUM> manages the battery apparatus <NUM> based on the voltages measured by the cell voltage sensing circuit <NUM>. In some embodiments, the processor <NUM> may control operations of the switches <NUM> and <NUM>. The processor <NUM> may be, for example, a micro controller unit (MCU).

The processor <NUM> may form a battery management system. In some embodiments, the battery management system may further include a cell voltage sensing circuit <NUM>.

<FIG>, <FIG>, and <FIG> are diagrams showing a connection relationship between a battery module and a cell voltage sensing circuit in a battery apparatus according to various embodiments, and <FIG> is a drawing showing an example of a bus-bar in a battery apparatus according to an embodiment.

Referring to <FIG>, <FIG>, and <FIG>, in a battery pack, a plurality of battery modules <NUM>, <NUM>, <NUM>, and <NUM> are connected in series. Although <FIG>, <FIG>, and <FIG> show four battery modules <NUM>, <NUM>, <NUM>, and <NUM> for convenience of description, the number of battery modules is not limited thereto.

Two adjacent battery modules are connected via a bus-bar. A bus-bar <NUM> connects the battery module <NUM> and the battery module <NUM>, a bus-bar <NUM> connects the battery module <NUM> and the battery module <NUM>, and a bus-bar <NUM> connects the battery module <NUM> and the battery module <NUM>. A first terminal of the bus-bar <NUM> may be connected to a node BBP1 corresponding to a negative terminal of the battery module <NUM>, and a second terminal of the bus-bar <NUM> may be connected to a node BBN1 corresponding to a positive terminal of the battery module <NUM>. Further, a first terminal of the bus-bar <NUM> may be connected to a node BBP2 corresponding to a negative terminal of the battery module <NUM>, and a second terminal of the bus-bar <NUM> may be connected to a node BBN2 corresponding to a positive terminal of the battery module <NUM>. Furthermore, a first terminal of the bus-bar <NUM> may be connected to a node BBP3 corresponding to a negative terminal of the battery module <NUM>, and a second terminal of the bus-bar <NUM> may be connected to a node BBN3 corresponding to a positive terminal of the battery module <NUM>. In some embodiments, the positive terminal of each battery module may be connected to a positive electrode of the last battery cell among a plurality of battery cells, which are included in the corresponding battery module and are connected in series, and the negative terminal of each battery module may be connected to a negative electrode of the first battery cell among the plurality of battery cells, which are included in the corresponding battery module and are connected in series.

In some embodiments, the bus-bars <NUM>, <NUM>, and <NUM> may be formed of a material having electrical conductivity. The bus-bars <NUM>, <NUM>, and <NUM> may be formed in various shapes according to a structure of the battery pack <NUM> or the battery modules <NUM>, <NUM>, <NUM> and <NUM>. For example, as shown in <FIG>, the bus-bar <NUM> may be connected with an electrode terminal 211a of one battery module <NUM> and an electrode terminal 212a of the other battery module <NUM> so as to connect the battery module <NUM> and the battery module <NUM>. The electrode terminal 211a of the battery module <NUM> may be a negative terminal of the battery module <NUM>, and the electrode terminal 212a of the battery module <NUM> may be a positive terminal of the battery module <NUM>.

In some embodiments, as shown in <FIG> and <FIG>, a cell voltage sensing circuit may be connected to two or more battery modules. In this case, the number of battery cells that can be sensed by the cell voltage sensing circuit may be greater than the number of battery cells included in one battery module. In some embodiments, when the cell voltage sensing circuit is provided as an integrated circuit (IC), the number of cell voltage sensing pins (or channels) in the cell voltage sensing IC may be greater than the number of battery cells included in one battery module.

Referring to <FIG>, a cell voltage sensing circuit <NUM> may be connected to a plurality of battery cells of battery modules <NUM> and <NUM> to measure a voltage of each of the battery cells, and the cell voltage sensing circuit <NUM> may be connected to a plurality of battery cells of battery module <NUM> and <NUM> to measure a voltage of each of the battery cells. In some embodiments, the cell voltage sensing circuit <NUM> may be connected to the plurality of battery cells of the battery module <NUM> and the plurality of battery cells of the battery module <NUM> through a plurality of sensing lines, and the cell voltage sensing circuit <NUM> may be connected to the plurality of battery cells of the battery module <NUM> and the plurality of battery cells of the battery module <NUM> through a plurality of sensing lines. The cell voltage sensing circuits <NUM> and <NUM> may sense voltages at the positive and negative electrodes of each battery cell and measure a voltage between the positive and negative electrodes as a voltage of the corresponding battery cell. In this case, a sensing line connected to a positive electrode of a certain battery cell to sense the positive electrode may be also connected to a negative electrode of an adjacent battery cell, and a sensing line connected to a negative electrode of a certain battery cell to sense the negative electrode may be also connected to a positive electrode of another adjacent battery cell.

Further, the cell voltage sensing circuit <NUM> may measure a voltage of a bus-bar <NUM> connecting the two battery modules <NUM> and <NUM>, and the cell voltage sensing circuit <NUM> may measure a voltage of a bus-bar <NUM> connecting the two battery modules <NUM> and <NUM>. The cell voltage sensing circuit <NUM> may measure a voltage between both terminals of the bus-bar <NUM>, i.e., a voltage between the two nodes BBP1 and BBN1, as the voltage of the bus-bar <NUM>, and the cell voltage sensing circuit <NUM>. may measure a voltage between both terminals of the bus-bar <NUM>, i.e., a voltage between the two nodes BBP3 and BBN3, as the voltage of the bus-bar <NUM>.

In some embodiments, each of the cell voltage sensing circuits <NUM> and <NUM> may be provided as a cell voltage sensing IC. In some embodiments, the cell voltage sensing IC <NUM> may include a plurality of pins respectively connected to a plurality of battery cells of the battery modules <NUM> and <NUM> and two pins respectively connected to both terminals BBP1 and BBN1 of the bus-bar <NUM>. Further, the cell voltage sensing IC <NUM> may include a plurality of pins respectively connected to a plurality of battery cells of the battery modules <NUM> and <NUM> and two pins respectively connected to both terminals BBP3 and BBN3 of the bus-bar <NUM>. In this case, the cell voltage sensing IC may measure the voltage of the bus-bar through two pins respectively connected to both terminals of the bus-bar, and measure the voltage of the battery cell through the pins connected to the battery cell.

Referring to <FIG>, in some embodiments, a cell voltage sensing circuit <NUM> may be connected to a plurality of battery cells of a battery module <NUM> and some battery cells of a battery module <NUM> to measure a voltage of each of the battery cells. The cell voltage sensing circuit <NUM> may be connected to remaining battery cells of the battery module <NUM> and some battery cells of a battery module <NUM> to measure a voltage of each of the battery cells. The cell voltage sensing circuit <NUM> may be connected to remaining battery cells of the battery module <NUM> and a plurality of battery cells of a battery module <NUM> to measure a voltage of each of the battery cells.

Further, the cell voltage sensing circuit <NUM> may measure a voltage of a bus-bar <NUM> connecting the two battery modules <NUM> and <NUM>, the cell voltage sensing circuit <NUM> may measure a voltage of a bus-bar <NUM> connecting the two battery modules <NUM> and <NUM>, and the cell voltage sensing circuit <NUM> may measure a voltage of a bus-bar <NUM> connecting the two battery modules <NUM> and <NUM>.

According to the above-described embodiments, since the cell voltage sensing circuit is connected to two or more battery modules, the number of cell voltage sensing circuits required for the battery apparatus can be reduced, thereby reducing the cost of the battery apparatus. In examples shown in <FIG> and <FIG>, although four cell voltage sensing circuits are required when a separate cell voltage sensing circuit is used for each battery module, two or three cell voltage sensing circuits can be used according to the above- described embodiments.

In some embodiments, as shown in <FIG>, two cell voltage sensing circuits may be connected to one battery module. In this case, the number of battery cells that can be sensed by the cell voltage sensing circuit may be less than the number of battery cells included in one battery module. In some embodiments, when the cell voltage sensing circuit is provided as a cell voltage sensing IC, the number of pins (or channels) of the cell voltage sensing IC may be less than the number of battery cells included in one battery module.

Referring to <FIG>, a cell voltage sensing circuit <NUM> may be connected to some battery cells of a battery module <NUM> to measure a voltage of each of the battery cells, a cell voltage sensing circuit <NUM> may be connected to remaining battery cells of the battery module <NUM> and some battery cells of a battery module <NUM> to measure a voltage of each of the battery cells, and a cell voltage sensing circuit <NUM> may be connected to remaining battery cells of the battery module <NUM> to measure a voltage of each of the battery cells. Further, a cell voltage sensing circuit <NUM> may be connected to some battery cells of a battery module <NUM> to measure a voltage of each of the battery cells, a cell voltage sensing circuit <NUM> may be connected to remaining battery cells of the battery module <NUM> and some battery cells of a battery module <NUM> to measure a voltage of each of the battery cells, and a cell voltage sensing circuit <NUM> may be connected to remaining battery cells of the battery module <NUM> to measure a voltage of each of the battery cells.

Furthermore, a cell voltage sensing circuit <NUM> may measures a voltage of a bus-bar <NUM> connecting the two battery modules <NUM> and <NUM>, and a cell voltage sensing circuit <NUM> may measure a voltage of a bus-bar <NUM> connecting the two battery modules <NUM> and <NUM>.

According to the above-described embodiments, since the cell voltage sensing circuit is connected to two or more battery modules, the number of cell voltage sensing circuits required for the battery apparatus can be reduced, thereby reducing the cost of the battery apparatus. In the example shown in <FIG>, although eight cell voltage sensing circuits are required when a separate cell voltage sensing circuit is used for each battery module, six cell voltage sensing circuits can be used according to the above-described embodiments.

Next, a voltage measurement of a battery cell is described with reference to <FIG>.

<FIG>, <FIG>, <FIG>, and <FIG> are diagrams for explaining a voltage measurement of a battery cell in a battery apparatus according to various embodiments. <FIG>, <FIG>, <FIG>, and <FIG> shows only battery cells around a bus-bar among battery cells of a battery module for convenience of description.

First, embodiments in which two battery modules connected to a bus-bar are connected to different cell voltage sensing circuits are described with reference to <FIG> and <FIG>. For example, as shown in <FIG>, battery modules <NUM> and <NUM> may be connected to the cell voltage sensing circuits <NUM> and <NUM>, respectively. Alternatively, as shown in <FIG>, battery modules <NUM> and <NUM> may be connected to cell voltage sensing circuits <NUM> and <NUM>, respectively.

Referring to <FIG>, a separate cell voltage sensing circuit may be connected to each battery module. That is, a cell voltage sensing circuit <NUM> may be connected to a battery module <NUM>, and a cell voltage sensing circuit <NUM> may be connected to a battery module <NUM>. When the number of battery cells that can be sensed by the cell voltage sensing circuit <NUM> or <NUM> is less than the number of battery cells included in the battery module <NUM> or <NUM> (e.g., a case of <FIG>), another cell voltage sensing circuit may be additionally connected to each battery module <NUM> or <NUM>. The two battery modules <NUM> and <NUM> may be connected by a bus-bar <NUM>.

A plurality of sensing lines of the cell voltage sensing circuit <NUM> are connected to a plurality of battery cells of the battery module <NUM>. In order to measure a voltage of a battery cell, one sensing line is connected to a contact of two adjacent battery cells, i.e., a negative electrode of one battery cell and a positive electrode of another battery cell. In the battery module <NUM>, a contact of two battery cells C1<NUM> and C1<NUM>, i.e., a positive electrode of the battery cell C1<NUM> and a negative electrode of the battery cell C1<NUM> are connected to a sensing line L1<NUM>, a contact of two battery cells C1<NUM> and C1<NUM>, i.e., a positive electrode of the battery cell C1<NUM> and a negative electrode of the battery cell C1<NUM> are connected to a sensing line L1<NUM>, and a contact of two battery cells C1<NUM> and C1<NUM>, i.e., a positive electrode of the battery cell C1<NUM> and a negative electrode of the battery cell C1<NUM> are connected to a sensing line L1<NUM>. In addition, a negative electrode of the battery cell C1<NUM> is connected to a sensing line L1<NUM>. In some embodiments, the sensing lines L1<NUM>, L1<NUM>, L1<NUM>, and L1<NUM> may be connected to a plurality of pins VC<NUM>, VC<NUM>, VC<NUM>, and VC<NUM> for cell voltage sensing in the cell voltage sensing circuit <NUM>, respectively.

Accordingly, the cell voltage sensing circuit <NUM> may measure a voltage of each battery cell based on a voltage difference between two adjacent corresponding sensing lines among the plurality of sensing lines L1<NUM>, L1<NUM>, L1<NUM>, and L1<NUM>. That is, the cell voltage sensing circuit <NUM> may measure, as the voltage of each battery cell, a voltage between a positive electrode of the corresponding battery cell and a positive electrode of an adjacent battery cell. In some embodiments, the cell voltage sensing circuit <NUM> may measure a voltage of each battery cell based on a voltage difference between two adjacent corresponding pins among the plurality of pins. For example, the cell voltage sensing circuit <NUM> may measure the voltage of the battery cell C1i based on the voltage difference between the two sensing lines L1i-<NUM> and L1i (i.e., the voltage difference between the two pins VCi-<NUM> and VCi, wherein i is an integer greater than or equal to one (<NUM>).

A plurality of sensing lines of the cell voltage sensing circuit <NUM> are connected to a plurality of battery cells of the battery module <NUM> and the bus-bar <NUM>. In the battery module <NUM>, a contact of two battery cells C1n-<NUM> and C1n, i.e., a positive electrode of the battery cell C1n-<NUM> and a negative electrode of the battery cell C1n are connected to a sensing line L1n-<NUM>, a contact of two battery cells C1n-<NUM> and C1n-<NUM>, i.e., a positive electrode of the battery cell C1n-<NUM> and a negative electrode of the battery cell C1n-<NUM> are connected to a sensing line L1n-<NUM>, and a contact of two battery cells C1n-<NUM> and C1n-<NUM>, i.e., a positive electrode of the battery cell C1n-<NUM> and a negative electrode of the battery cell C1n-<NUM> are connected to a sensing line L1n-<NUM>. Further, a positive electrode of the battery cell C1n is connected to a sensing line L1n, and a second terminal BBN of the bus-bar <NUM> is connected to the sensing line L1n through the positive electrode of the battery cell C1n. Furthermore, a first terminal BBP of the bus-bar <NUM> is connected to a sensing line L1B.

In some embodiments, the plurality of sensing lines L1n-<NUM>, L1n-<NUM>, L1n-<NUM>, and L1n may be connected to a plurality of pins VCn-<NUM>, VCn-<NUM>, VCn-<NUM>, and VCn for cell voltage sensing in the cell voltage sensing circuit <NUM>, respectively. Further, the sensing line L1n may be connected to a pin VBN for the bus-bar <NUM> in the cell voltage sensing circuit <NUM> as well as the pin VCn. Furthermore, the sensing line L1B may be connected to another pin VBP for the bus-bar <NUM> in the cell voltage sensing circuit <NUM>.

Accordingly, the cell voltage sensing circuit <NUM> may measure a voltage of each battery cell based on a voltage difference between two adjacent corresponding sensing lines among the plurality of sensing lines L1n-<NUM>, L1n-<NUM>, L1n-<NUM>, and L1n. That is, the cell voltage sensing circuit <NUM> may measure, as the voltage of each battery cell, a voltage between a positive electrode of the corresponding battery cell and a positive electrode of an adjacent battery cell. In some embodiments, the cell voltage sensing circuit <NUM> may measure the voltage of each battery cell based on a voltage difference between two adjacent corresponding pins among the plurality of pins VCn-<NUM>, VCn-<NUM>, VCn-<NUM>, and VCn. Further, the cell voltage sensing circuit <NUM> may measure the voltage of the bus-bar <NUM>, i.e., a voltage between both terminals of the bus-bar <NUM> based on a voltage difference between the two sensing lines L1n and L1B (i.e., a voltage difference between the two pins VBP and VBN).

In some other embodiments, unlike the embodiment described with reference to <FIG>, the cell voltage sensing circuits <NUM> and <NUM> may measure, as the voltage of each battery cell, a voltage between a negative electrode of the corresponding battery cell and a negative electrode of an adjacent battery cell. In this case, the voltage of the bus-bar <NUM> may be measured by the cell voltage sensing circuit <NUM>. As shown in <FIG>, a first terminal BBP of the bus-bar <NUM> may be connected to a sensing line L1<NUM> through the negative electrode of the battery cell C1<NUM> of the battery module <NUM>. Further, a second terminal BBN of the bus-bar <NUM> may be connected to a sensing line L1B. In some embodiments, the sensing line L1<NUM> may be connected to a pin VBP for the bus-bar <NUM> in the cell voltage sensing circuit <NUM> as well as a pin VC<NUM>. Furthermore, the sensing line L1B may be connected to another pin VBN for the bus-bar <NUM> in the cell voltage sensing circuit <NUM>. Accordingly, the cell voltage sensing circuit <NUM> may measure the voltage of the bus-bar <NUM> based on a voltage difference between the two sensing lines L1<NUM> and L1B (i.e., a voltage difference between the two pins VBP and VBN).

Next, embodiments in which two battery modules connected to a bus-bar are connected to the same cell voltage sensing circuit are described with reference to <FIG> and <FIG>. For example, as shown in <FIG>, <FIG>, and <FIG>, the battery modules <NUM> and <NUM> may be connected to the cell voltage sensing circuit <NUM>, <NUM> or <NUM>, or the battery modules <NUM> and <NUM> may be connected to the cell voltage sensing circuit <NUM>, <NUM> or <NUM>. Alternatively, as shown in <FIG>, the battery modules <NUM> and <NUM> may be connected to the cell voltage sensing circuit <NUM>.

Referring to <FIG>, a cell voltage sensing circuit <NUM> is connected to battery modules <NUM> and <NUM> and a bus-bar <NUM> connecting the two battery modules <NUM> and <NUM> to measure a voltage of each of the battery cells and a voltage of the bus-bar <NUM>. As described with reference to <FIG>, <FIG>, and <FIG>, the cell voltage sensing circuit <NUM> may be connected to some battery cells of the battery module <NUM> or <NUM> or to all battery cells of the battery module <NUM>.

A plurality of sensing lines of the cell voltage sensing circuit <NUM> are connected to a plurality of battery cells of the battery modules <NUM> and <NUM>, and a bus-bar <NUM>, respectively. In order to measure a voltage of a battery cell, one sensing line is connected to a contact of two adjacent battery cells, i.e., a negative electrode of one battery cell and a positive electrode of another battery cell. In the battery module <NUM>, a contact of two battery cells C2<NUM> and C2<NUM>, i.e., a positive electrode of the battery cell C2<NUM> and a negative electrode of the battery cell C2<NUM> is connected to a sensing line L2<NUM>, a contact of two battery cells C2<NUM> and C2<NUM>, i.e., a positive electrode of the battery cell C2<NUM> and a negative electrode of the battery cell C2<NUM> are connected to a sensing line L2<NUM>, and a contact of two battery cells C2<NUM> and C2<NUM>, i.e., a positive electrode of the battery cell C2<NUM> and a negative electrode of the battery cell C2<NUM> are connected to a sensing line L2<NUM>. Further, in the battery module <NUM>, a contact of two battery cells C2n-<NUM> and C2n, i.e., a positive electrode of the battery cell C2n-<NUM> and a negative electrode of the battery cell C2n are connected to a sensing line L2n-<NUM>, a contact of two battery cells C2n-<NUM> and C2n-<NUM>, i.e., a positive electrode of the battery cell C2n-<NUM> and a negative electrode of the battery cell C2n-<NUM> are connected to a sensing line L2n-<NUM>, and a contact of two battery cells C2n-<NUM> and C2n-<NUM>, i.e., a positive electrode of the battery cell C2n-<NUM> and a negative electrode of the battery cell C2n-<NUM> are connected to a sensing line L2n-<NUM>.

Because of the bus-bar <NUM>, the negative electrode of the first battery cell C2<NUM> of the battery module <NUM> and a positive electrode of a battery cell adjacent to the battery cell C2<NUM>, i.e., the last battery cell C2n of the battery module <NUM> cannot be connected to the same sensing line. Accordingly, the negative electrode of the first battery cell C2<NUM> of the battery module <NUM> is connected to a sensing line L2<NUM>, and the positive electrode of the last battery cell C2n of the battery module <NUM> is connected to a sensing line L2n. Since a first terminal BBP of the bus-bar <NUM> is connected to the negative electrode of the battery cell C2<NUM> which is a negative terminal of the battery module <NUM>, the first terminal BBP of the bus-bar <NUM> is connected to the sensing line L2<NUM> through the the negative electrode of the battery cell C2<NUM>. Further, since a second terminal BBN of the bus-bar <NUM> is connected to the positive electrode of the battery cell C2n which is a positive terminal of the battery module <NUM>, the second terminal BBN of the bus-bar <NUM> is connected to the sensing line L2n through the positive electrode of the battery cell C2n.

In some embodiments, the plurality of sensing lines L2<NUM>, L2<NUM>, L2<NUM>, L2n, L2n-<NUM>, L2n-<NUM>, and L2n-<NUM> may be connected to a plurality of pins VCk+<NUM>, VCk+<NUM>, VCk+<NUM>, VCk, VCk-<NUM>, VCk-<NUM>, and VCk-<NUM> for cell voltage sensing in the cell voltage sensing circuit <NUM>, respectively. Further, the sensing line L2n may be connected to a pin VBN for the bus-bar <NUM> in the cell voltage sensing circuit <NUM> as well as a pin VCk. Furthermore, the sensing line L2<NUM> may be connected to another pin VBP for the bus-bar <NUM> in the cell voltage sensing circuit <NUM>. In this case, the sensing line L2<NUM> is not connected to the pin for cell voltage sensing.

Accordingly, the cell voltage sensing circuit <NUM> may measure a voltage of each battery cell based on based on a voltage difference between two adjacent corresponding sensing lines among the plurality of sensing lines L2<NUM>, L2<NUM>, L2<NUM>, L2n, L2n-<NUM>, L2n-<NUM>, and L2n-<NUM>. That is, the cell voltage sensing circuit <NUM> may measure, as the voltage of each battery cell, a voltage between a positive electrode of the corresponding battery cell and a positive electrode of an adjacent battery cell. In some embodiments, the cell voltage sensing circuit <NUM> may measure a voltage of each battery cell based on a voltage difference between two adjacent corresponding pins among the plurality of pins VCk+<NUM>, VCk+<NUM>, VCk+<NUM>, VCk, VCk-<NUM>, VCk-<NUM>, and VCk-<NUM>.

In this case, the cell voltage sensing circuit <NUM> measures the voltage of the first battery cell C2<NUM> of the battery module <NUM> based on a voltage difference between the sensing lines L2<NUM> and L2n (i.e., a voltage difference between the two pins VCk+<NUM> and VCk). That is, since the voltage of the first battery cell C2<NUM> is measured as the voltage between the positive electrode of the battery cell C2<NUM> and the positive electrode of the adjacent battery cell (i.e., the last battery cell C2n of the battery module <NUM>), the voltage of the first battery cell C2<NUM> may be measured as a sum of an actual voltage of the battery cell C2<NUM> and the voltage of the bus-bar <NUM>.

Accordingly, the cell voltage sensing circuit <NUM> may determine the voltage of the first battery cell C2<NUM> by correcting the measured voltage of the first battery cell C2<NUM> with the voltage of the bus-bar <NUM>. In some embodiments, the cell voltage sensing circuit <NUM> may determine a voltage obtained by subtracting the voltage of the bus-bar <NUM> from the measured voltage of the first battery cell C2<NUM> as the voltage of the first battery cell C2<NUM>. In this case, the cell voltage sensing circuit <NUM> may measure the voltage of the bus-bar <NUM> based on a voltage difference between the two sensing lines L2<NUM> and L2n connected to the bus-bar <NUM> (i.e., a voltage difference between the two pins VBP and VBn).

In some other embodiments, unlike the embodiments described with reference to <FIG>, a cell voltage sensing circuit <NUM> may measure, as a voltage of each battery cell, a voltage between a negative electrode of the corresponding battery cell and a negative electrode of an adjacent battery cell. As shown in <FIG>, a first terminal BBP of a bus-bar <NUM> is connected to a sensing line L2<NUM> through the negative electrode of the battery cell C2<NUM>. Further, since a second terminal BBN of the bus-bar <NUM> is connected to the positive electrode of the battery cell C2n which is the positive terminal of the battery module <NUM>, the second terminal BBN of the bus-bar <NUM> is connected to the sensing line L2n through the positive electrode of the battery cell C2n. In some embodiments, the sensing line L2<NUM> may be connected to a pin VBP for the bus-bar <NUM> in the cell voltage sensing circuit <NUM> as well as a pin VCk. Further, the sensing line L2n may be connected to another pin VBN for the bus-bar <NUM> in the cell voltage sensing circuit <NUM>. In this case, the sensing line L2n is not connected to the pin for sensing the cell voltage.

In this case, the cell voltage sensing circuit <NUM> measures the voltage of the last battery cell C2n of the battery module <NUM> based on a voltage difference between the sensing lines L2<NUM> and L2n-<NUM> (i.e., a voltage difference between the two pins VCk and VCk-<NUM>). That is, since the voltage of the last battery cell C2n is measured as the voltage between the negative electrode of the battery cell C2n and the negative electrode of the adjacent battery cell (i.e., the first battery cell C2<NUM> of the battery module <NUM>), the voltage of the last battery cell C2n may be measured as a sum of an actual voltage of the battery cell C2n and the voltage of the bus-bar <NUM>.

Accordingly, the cell voltage sensing circuit <NUM> may determine the voltage of the last battery cell C2n by correcting the measured voltage of the last battery cell C2n with the voltage of the bus-bar <NUM>. In some embodiments, the cell voltage sensing circuit <NUM> may determine a voltage obtained by subtracting the voltage of the bus-bar <NUM> from the measured voltage of the last battery cell C2n as the voltage of the last battery cell C2n. In this case, the cell voltage sensing circuit <NUM> may measure the voltage of the bus-bar <NUM> based on a voltage difference between the two sensing lines L2<NUM> and L2n-<NUM> connected to the bus-bar <NUM> (i.e., a voltage difference between the two pins VBP and VBn).

According to the above-described embodiments, one cell voltage sensing circuit may be connected to a plurality of battery modules, and the voltage of the bus-bar included in the measured voltage of the battery cell may be compensated.

Next, a method of measuring a cell voltage in a battery apparatus according to an embodiment is described with reference to <FIG>.

<FIG> is a flowchart showing a method of measuring a cell voltage in a battery apparatus according to an embodiment.

Referring to <FIG>, a cell voltage sensing circuit of a battery management system measures voltages of battery cells of a battery module at S1010. Further, the cell voltage sensing circuit measures a voltage of a bus-bar at S1010. A processor (e.g., <NUM> in <FIG>) receives the voltages of the battery cells and the voltage of the bus-bar from the cell voltage sensing circuit at S1020.

The processor <NUM> determines whether two battery modules share a cell voltage sensing circuit at S1030. That is, the processor <NUM> determines whether the voltage of the first battery cell of one battery module and the voltage of the last battery cell of another battery module are measured in the same cell voltage sensing circuit at S1030. When the two battery modules share the cell voltage sensing circuit, the processor <NUM> corrects the voltage of the battery cell (i.e., the first battery cell or the last battery cell) connected to the bus-bar based on the voltage of the bus-bar at S1040. In some embodiments, the processor <NUM> may correct the voltage of the battery cell connected to the busbar by subtracting the voltage of the busbar from the voltage of the battery cell connected to the busbar.

Claim 1:
A method of measuring a cell voltage of a battery apparatus (<NUM>) including a first battery module (<NUM>) and a second battery module (<NUM>), the method comprising:
measuring a voltage of each battery cell using a cell voltage sensing circuit (<NUM>, <NUM>) shared by at least some battery cells of the first battery module (<NUM>) and at least some battery cells of the second battery module (<NUM>);
measuring a voltage of a bus-bar (<NUM>) connecting the first battery module (<NUM>) and the second battery module (<NUM>) using the cell voltage sensing circuit (<NUM>, <NUM>, <NUM>); and
correcting a voltage of at least one battery cell among the some battery cells of the first battery module (<NUM>) and the some battery cells of the second battery module (<NUM>) based on the voltage of the bus-bar (<NUM>).