US-12625217-B2 - Method and apparatus for diagnosing battery voltage measurement error

US12625217B2US 12625217 B2US12625217 B2US 12625217B2US-12625217-B2

Abstract

A method of diagnosing a voltage measurement error of a battery pack including a plurality of battery cells, the method including: measuring a voltage across opposite ends of each battery cell and performing cell balancing if a voltage difference between the battery cells satisfies a predetermined balancing condition; measuring a cell balancing current flowing through a cell balancing circuit directly connected to opposite ends of a battery cell for which cell balancing is performed; and diagnosing a voltage measurement error based on a difference between a measured cell voltage and a calculated cell voltage of a battery cell, calculated based on a resistance of the cell balancing circuit and the cell balancing current.

Inventors

Sungchun Cho

Assignees

SAMSUNG SDI CO., LTD.

Dates

Publication Date: 20260512
Application Date: 20240110
Priority Date: 20230913

Claims (11)

1 . A method of diagnosing a voltage measurement error of a battery pack including a plurality of battery cells, the method comprising: measuring a voltage across opposite ends of each battery cell and performing cell balancing based on a voltage difference between the battery cells satisfies satisfying a predetermined balancing condition; measuring a cell balancing current flowing through a cell balancing circuit directly connected to opposite ends of a battery cell for which cell balancing is performed; and diagnosing a voltage measurement error based on a difference between a measured cell voltage and a calculated cell voltage of a battery cell, calculated based on a resistance of the cell balancing circuit and the cell balancing current, wherein the performing of the cell balancing further includes: measuring the voltage across the opposite ends of each battery cell; and determining a battery cell having a measured voltage greater than other battery cells as a cell balancing target, based on the voltage difference between the battery cells being greater than or equal to a predetermined threshold value.
2 . The method as claimed in claim 1 , wherein the performing of the cell balancing further comprises: closing a switch provided in a cell balancing circuit directly connected to the opposite ends of the battery cell that is determined as the cell balancing target and comprises a resistor and the switch to perform cell balancing.
3 . The method as claimed in claim 1 , wherein the measuring of the cell balancing circuit comprises measuring a cell balancing current flowing through a closed circuit comprising the battery cell for which cell balancing is performed, a resistor provided in the cell balancing circuit, and a switch provided in the cell balancing circuit.
4 . The method as claimed in claim 3 , wherein the diagnosing of the voltage measurement error comprises: obtaining the measured cell voltage by measuring the voltage across the opposite ends of the battery cell for which cell balancing is performed; and obtaining the calculated cell voltage of the battery cell for which cell balancing is performed, calculated based on a resistance of the cell balancing circuit and the cell balancing current.
5 . The method as claimed in claim 4 , wherein the diagnosing of the voltage measurement error comprises diagnosing that an error occurs in a voltage measurement unit of the battery pack based on the difference between the measured cell voltage and the calculated cell voltage being greater than or equal to a predetermined threshold value.
6 . A non-transitory computer-readable medium storing instructions that, when executed by one or more processors, cause the one or more processors to execute the method according to claim 1 .
7 . An apparatus for diagnosing a voltage measurement error of a battery pack including a plurality of battery cells, the apparatus comprising: a voltage measurement unit electrically connected to opposite ends of each battery cell and configured to measure a voltage of each battery cell; a cell balancing circuit directly connected to the opposite ends of each battery cell and configured to have a cell balancing current of each battery cell flow therethrough; a current measurement unit configured to measure a current flowing through the cell balancing circuit; and a processor configured to perform cell balancing based on a voltage difference between the battery cells satisfying a predetermined balancing condition based on the voltage across the opposite ends of each battery cell and to diagnose a voltage measurement error based on a difference between a measured cell voltage and a calculated cell voltage of a battery cell, calculated based on a resistance of the cell balancing circuit and the cell balancing current, wherein the processor is further configured to obtain a voltage across opposite ends of each battery cell, to determine a battery cell having a measured voltage greater than other battery cells as a cell balancing target, based on the voltage difference between the battery cells being greater than or equal to a predetermined threshold value.
8 . The apparatus as claimed in claim 7 , wherein the processor is further configured to close a switch provided in a cell balancing circuit directly connected to the opposite ends of the battery cell that is determined as the cell balancing target and comprises a resistor and the switch to perform cell balancing.
9 . The apparatus as claimed in claim 7 , wherein the processor is further configured to obtain, from the current measurement unit, a cell balancing current flowing through a closed circuit comprising the battery cell for which cell balancing is performed, a resistor provided in the cell balancing circuit, and a switch provided in the cell balancing circuit.
10 . The apparatus as claimed in claim 9 , wherein the processor is further configured to obtain the measured cell voltage by measuring the voltage across the opposite ends of the battery cell for which cell balancing is performed, and to obtain the calculated cell voltage of the battery cell for which cell balancing is performed, calculated based on a resistance of the cell balancing circuit and the cell balancing current.
11 . The apparatus as claimed in claim 10 , wherein the processor is further configured to diagnose that an error occurs in the voltage measurement unit based on the difference between the measured cell voltage and the calculated cell voltage being greater than or equal to a predetermined threshold value.

Description

CROSS-REFERENCE TO RELATED APPLICATION The present application claims priority to and the benefit of Korean Patent Application No. 10-2023-0121911, filed on Sep. 13, 2023, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. BACKGROUND 1. Field Aspects of one or more embodiments relate to a method and apparatus for diagnosing a battery voltage measurement error. 2. Description of the Related Art Recently, consumer demand for portable electronic products such as laptops, video cameras, portable phones, etc., have increased rapidly, and as the development of energy storage batteries, robots, satellites, etc., is rapidly advancing, research on high-performance secondary batteries that can be repeatedly charged and discharged has been actively pursued. In measuring the voltage of secondary batteries, voltage mismeasurement may occur due errors, etc., caused by a voltage sensing circuit unit that measures the voltage of a secondary battery. In this case, a cell balancing operation of balancing cell voltages of a plurality of battery cells may be performed, and in this situation, a problem such as over-charge, over-discharge, etc., may occur due to voltage mismeasurement. The above information disclosed in this Background section is only for enhancement of understanding of the background and therefore the information discussed in this Background section does not necessarily constitute prior art. SUMMARY Aspects of one or more embodiments include a method, a computer program, and an apparatus for diagnosing a battery voltage measurement error, wherein a battery voltage measurement error may be effectively diagnosed in a process of diagnosing the battery voltage measurement error. However, such characteristics are merely examples, and the scope of embodiments according to the present disclosure are not limited thereto. Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the present disclosure. According to one or more embodiments, a method of diagnosing a voltage measurement error of a battery pack including a plurality of battery cells includes measuring a voltage across opposite ends of each battery cells and performing cell balancing if a voltage difference between the battery cells satisfies a predetermined balancing condition, measuring a cell balancing current flowing through a cell balancing circuit directly connected to opposite ends of a battery cell for which cell balancing is performed, and diagnosing a voltage measurement error based on a measured cell voltage and a difference between a calculated cell voltage of a battery cell, calculated based on a resistance of the cell balancing circuit and the cell balancing current. According to some embodiments, the performing of the cell balancing may include measuring the voltage across the opposite ends of each battery cell, determining a battery cell having a measured voltage greater than other battery cells as a cell balancing target, if the voltage difference between the battery cells is greater than or equal to a predetermined threshold value, and closing a switch provided in a cell balancing circuit directly connected to the opposite ends of the battery cell that is determined as the cell balancing target and includes a resistor and the switch to perform cell balancing. According to some embodiments, the measuring of the cell balancing circuit may include measuring a cell balancing current flowing through a closed circuit including the battery cell for which cell balancing is performed, the resistor provided in the cell balancing circuit, and the switch provided in the cell balancing circuit. According to some embodiments, the diagnosing of the voltage measurement error may include obtaining the measured cell voltage by measuring the voltage across the opposite ends of the battery cell for which cell balancing is performed and obtaining the calculated cell voltage of the battery cell for which cell balancing is performed, calculated based on a resistance of the cell balancing circuit and the cell balancing current. According to some embodiments, the diagnosing of the voltage measurement error may include diagnosing that an error occurs in a voltage measurement unit of the battery pack if the difference between the measured cell voltage and the calculated cell voltage is greater than or equal to a predetermined threshold value. According to some embodiments, a computer program is stored on a recording medium to execute the above-described method by using a computing device. According to some embodiments, an apparatus for diagnosing a voltage measurement error of a battery pack including a plurality of battery cells includes a voltage measurement unit electrically connected to opposite ends of each battery cell to measure a voltage of each battery cell, a cell