KR-20260065770-A - BATTERY MANAGEMENT SYSTEM, BATTERY MANAGEMENT METHOD, BATTERY PAKC, AND ELECTRIC VEHICLE

KR20260065770AKR 20260065770 AKR20260065770 AKR 20260065770AKR-20260065770-A

Abstract

A battery management system, a battery management method, a battery pack, and an electric vehicle are provided. The battery management system comprises: a sensing unit configured to generate a sensing signal representing the voltage and current of a battery; a memory unit configured to store a reference charging map for constant current charging using a first to m-th reference current rate, wherein m is a natural number greater than or equal to 2; and a control unit configured to determine a starting value representing a charging factor of the battery at the time of receiving the charging command based on the sensing signal when a charging command is received. The charging factor is the SOC or voltage of the battery. The control unit is configured to generate a first to m-th reference charging function corresponding one-to-one with the first to m-th reference current rate from the reference charging map. When a charging cycle including the constant current charging is initiated, the control unit is configured to control a charging current supplied to the battery by sequentially using the first to m-th reference current rates based on the sensing signal, the starting value, and the first to m-th reference charging function.

Inventors

남기민
김형석
황태현
조원태

Assignees

주식회사 엘지에너지솔루션

Dates

Publication Date: 20260511
Application Date: 20260420

Claims (15)

A memory unit configured to store at least one reference charging function generated based on a reference charging map; and A control unit that, upon receiving a charging command, determines a charging factor of the battery based on a sensing signal representing at least one of the voltage, current, or temperature of the battery, and supplies a charging current to the battery based on a multi-stage constant current protocol of the reference charging map until the charging factor reaches a first switching value according to the at least one reference charging function; A battery management system including
In paragraph 1, A battery management system in which the switching condition according to the reference charging map and the switching condition according to the reference charging function are different for at least one current rate according to the multi-stage constant current protocol.
In paragraph 1, The above control unit is, A battery management system that, upon receiving the above charging command, supplies a charging current of a first reference current rate, which is the current rate of the first order according to the multi-stage constant current protocol of the reference charging map, to the battery.
In paragraph 1, The above control unit is, A battery management system that supplies a charging current of a second reference current rate, which is a second sequence current rate according to the multi-stage constant current protocol, to the battery when the charging factor reaches the first switching value.
In paragraph 1, The above memory unit is, The first to the mth reference charging functions generated based on the above reference charging map are stored, wherein m is a natural number greater than or equal to 2, and The above control unit is, Using the above first to mth reference charging function, the first to mth conversion values are determined based on the charging factor at the time of receiving the charging command, and A battery management system configured to control the current rate of the charging current to be equal to the i-th reference current rate, which is the current rate of the i-th order according to the multi-stage constant current protocol, from the time the charging factor reaches the i-1-th switching value until it reaches the i-th switching value, wherein i is a natural number greater than or equal to 2 and less than or equal to m.
In paragraph 5, The above reference charging map includes the first to the mth reference arrays, and Each reference array includes first to n boundary values corresponding one-to-one with first to n reference values, wherein n is a natural number greater than or equal to 2, and Let i be a natural number between 2 and m inclusive, and j be a natural number between 1 and n inclusive, The j-th boundary value of the first reference array above represents a limit value at which constant current charging by the first reference current rate is allowed from the point in time when the charging factor is equal to the j-th reference value, and A battery management system in which the j-th boundary value of the i-th reference array represents a limit value at which constant current charging is allowed by the i-th reference current rate, which is the current rate of the i-th order according to the multi-stage constant current protocol, from the point in time when the charging factor is the same as the j-th boundary value of the i-1-th reference array.
In paragraph 1, The above control unit is, A battery management system configured to generate at least one reference charging function by applying mathematical operations to the above reference charging map.
In Paragraph 7, The above mathematical operation is a battery management system that is the least squares method.
In paragraph 6, A battery management system in which the above i-th reference current rate is smaller than the i-1-th reference current rate.
In paragraph 5, The above control unit is, A battery management system configured to switch from constant current charging to constant voltage charging based on a reference current rate in response to the charging factor reaching the m-th switching value.
A battery pack comprising the battery management system according to any one of claims 1 to 10.
An electric vehicle comprising the above battery pack according to Clause 11.
A step of acquiring a sensing signal indicating at least one of the voltage, current, or temperature of a battery; A step of determining the charge factor of the battery based on the sensing signal upon receiving a charging command; and A step of supplying a charging current to the battery based on a multi-stage constant current protocol of the reference charging map until the charging factor reaches a first switching value according to at least one reference charging function generated based on the reference charging map; A battery management method including
In Paragraph 13, A step of supplying a charging current of a second reference current rate, which is a current rate of the second order according to the multi-stage constant current protocol, to the battery when the charging factor reaches the first switching value; A battery management method that further includes
In Paragraph 13, A step of determining the first to m-th conversion values based on the charging factor at the time of receiving the charging command, using the first to m-th reference charging function generated based on the above reference charging map, wherein m is a natural number greater than or equal to 2; and A step of controlling the current rate of the charging current to be equal to the i-th reference current rate, which is the current rate of the i-th order according to the multi-stage constant current protocol, from the time the charging factor reaches the i-1st switching value until it reaches the i-th switching value; A battery management method that further includes, wherein i is a natural number between 2 and m.

Description

Battery Management System, Battery Management Method, Battery Pack, and Electric Vehicle The present invention relates to a technology for charging a battery. Recently, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has increased rapidly, and the development of electric vehicles, energy storage batteries, robots, and satellites has accelerated, research on high-performance batteries capable of repeated charging and discharging is actively underway. Currently commercialized batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium batteries. Among these, lithium batteries are gaining attention for their advantages, such as the ability to freely charge and discharge with almost no memory effect compared to nickel-based batteries, a very low self-discharge rate, and high energy density. When charging a battery with constant current, if the charging current rate is low, it takes a very long time to fully charge the battery. On the other hand, if the charging current rate is excessively high, there is a side effect of the battery degrading rapidly. Therefore, during constant current charging, it is necessary to adjust the charging current rate in stages according to the condition of the battery. A charging map having a 'multi-stage constant-current charging protocol' is primarily utilized to control the current rate in stages during constant-current charging. The charging map includes at least one data array in which the relationships between multiple current rates and multiple switching conditions are recorded. Whenever each switching condition is satisfied, the next sequence of current rates can be supplied to the battery as the charging current. The current rate (which may also be referred to as the 'C-rate') is the value obtained by dividing the charging current by the maximum capacity of the battery, and the unit used is 'C'. In the same charging cycle, as charging progresses, stress caused by the charging current accumulates, such as an increase in polarization voltage, which can cause damage to the battery (e.g., lithium metal deposition). Therefore, it is common for a charging map to be created such that the charging current rate decreases in steps from the beginning to the end of charging. For example, in a charging map, the current rate (e.g., 1.5 C) corresponding to the current transition condition (e.g., SOC 50%) is higher than the current rate (e.g., 1.4 C) corresponding to the next transition condition (e.g., SOC 60%). However, conventional charging maps are designed on the premise that a charging cycle is initiated from a fully discharged state (e.g., SOC 0%). Consequently, even if the battery is not fully discharged, the current rate of the charging current is unconditionally limited by the charging map. For example, when a charging cycle is initiated when the battery's SOC is 55%, the maximum value among multiple current rates (e.g., 2.0 C) cannot be used as the charging current, and constant current charging is initiated using a current rate smaller than the maximum value (e.g., 1.5 C). As a result, there is a disadvantage that the time required to complete charging is unnecessarily increased. The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is a diagram illustrating the configuration of an electric vehicle according to one embodiment of the present invention. Figure 2 is a diagram showing an exemplary reference charging map. Figure 3 is a figure referenced to illustrate an exemplary reference charging function generated from a reference charging map. FIG. 4 is a flowchart exemplarily illustrating a battery management method according to a first embodiment of the present invention. FIG. 5 is a flowchart illustrating an exemplary battery management method according to a second embodiment of the present invention. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, and should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention; thus, i