Patent Application
20250116717
This application claims priority to and the benefit of Korean Patent Application No. 10-2022-0064229 filed in the Korean Intellectual Property Office on May 25, 2022, the entire contents of which are incorporated herein by reference.
Embodiments disclosed herein relate to a battery management apparatus and an operating method thereof.
An electric vehicle is supplied with electricity from outside to charge a battery, and then a motor is driven by a voltage charged in the battery to obtain power. The battery of the electric vehicle may have heat generated therein by chemical reaction occurring in a process of charging and discharging electricity, and the heat may impair performance and lifetime of the battery. Thus, a battery management apparatus (or a battery management system (BMS)) that monitors and controls temperature, voltage, and current of the battery is driven to diagnose the state of the battery.
However, a conventional battery management apparatus has a difficulty in detecting a battery cell where heat is generated inside a battery bank unless a thermistor is attached to each battery bank including a plurality of battery cells to measure a temperature.
The conventional battery management apparatus may detect a heat-generated battery cell inside the battery by measuring a direct current resistance (DCR) of each battery bank, but large equipment is used in measurement of the direct current resistance, such that measurement of the direct current resistance may be possible only when the battery bank is being charged and measurement may be impossible during the use of the battery bank, degrading effectiveness.
Embodiments disclosed herein aim to provide a battery management apparatus and an operating method thereof, that may determine whether an abnormal battery cell exists in a battery bank based on an impedance of a battery bank, obtained by measuring a current and a voltage of the battery bank.
Technical problems of the embodiments disclosed herein are not limited to the above-described technical problems, and other unmentioned technical problems would be clearly understood by one of ordinary skill in the art from the following description.
A battery management apparatus according to an embodiment disclosed herein includes a switch connected to a plurality of battery banks including a plurality of battery cells and a controller configured to apply a control signal for repeatedly turning on or off the switch, measure a voltage value and a current value of each of the plurality of battery banks, and determine whether the plurality of battery cells included in each of the plurality of battery banks are abnormal based on an alternating current impedance of each of the plurality of battery banks calculated based on the voltage value and the current value of each of the plurality of battery banks.
According to an embodiment, the controller may be further configured to obtain a real value and an imaginary value of the voltage value and the current value of each of the plurality of battery banks by performing Fourier transform on the voltage value and the current value of each of the plurality of battery banks.
According to an embodiment, the controller may be further configured to obtain an imaginary value of an impedance of each of the plurality of battery banks based on the real value and the imaginary value of the voltage value and the current value of each of the plurality of battery banks.
According to an embodiment, the controller may be further configured to determine that a heat-generated battery cell that generates heat exists in at least any one of the plurality of battery cells inside any one of the plurality of battery banks when an imaginary value of an impedance of any one of the plurality of battery banks exceeds a threshold value.
According to an embodiment, the controller may be further configured to determine that a heat-generated battery cell that generates heat exists in at least any one of the plurality of battery cells inside any one of the plurality of battery banks when an imaginary value of an impedance of any one of the plurality of battery banks falls beyond a threshold error range of an imaginary value of an impedance of a battery bank serially connected to any one of the plurality of battery banks.
An operating method of a battery management apparatus according to an embodiment disclosed herein includes applying a control signal for repeatedly turning on or off a switch connected to a plurality of battery banks including a plurality of battery cells, measuring a voltage value and a current value of each of the plurality of battery banks, calculating an alternating current impedance of each of the plurality of battery banks based on the voltage value and the current value of each of the plurality of battery banks, and determining whether the plurality of battery cells included in each of the plurality of battery banks are abnormal based on the alternating current impedance of each of the plurality of battery banks.
According to an embodiment, the calculating of the alternating current impedance of each of the plurality of battery banks based on the voltage value and the current value of each of the plurality of battery banks may include obtaining a real value and an imaginary value of the voltage value and the current value of each of the plurality of battery banks by performing Fourier transform on the voltage value and the current value of each of the plurality of battery banks.
According to an embodiment, the calculating of the alternating current impedance of each of the plurality of battery banks based on the voltage value and the current value of each of the plurality of battery banks may include obtaining an imaginary value of an impedance of each of the plurality of battery banks based on the real value and the imaginary value of the voltage value and the current value of each of the plurality of battery banks.
According to an embodiment, the determining of whether the plurality of battery cells included in each of the plurality of battery banks are abnormal based on the alternating current impedance of each of the plurality of battery banks may include determining that a heat-generated battery cell that generates heat exists in at least any one of the plurality of battery cells inside any one of the plurality of battery banks when an imaginary value of an impedance of any one of the plurality of battery banks exceeds a threshold value.
According to an embodiment, the determining of whether the plurality of battery cells included in each of the plurality of battery banks are abnormal based on the alternating current impedance of each of the plurality of battery banks may include determining that a heat-generated battery cell that generates heat exists in at least any one of the plurality of battery cells inside any one of the plurality of battery banks when an imaginary value of an impedance of any one of the plurality of battery banks falls beyond a threshold error range of an imaginary value of an impedance of a battery bank serially connected to any one of the plurality of battery banks.
According to an embodiment, the threshold value may be a previously stored value.
With the battery management apparatus and the operating method thereof according to an embodiment disclosed herein, it may be determined whether an abnormal battery cell exists inside a battery bank based on an impedance of the battery bank measured by a current and a voltage of the battery bank.
Hereinafter, some embodiments disclosed in this document will be described in detail with reference to the exemplary drawings. In adding reference numerals to components of each drawing, it should be noted that the same components are given the same reference numerals even though they are indicated in different drawings. In addition, in describing the embodiments disclosed in this document, when it is determined that a detailed description of a related known configuration or function interferes with the understanding of an embodiment disclosed in this document, the detailed description thereof will be omitted.
To describe a component of an embodiment disclosed herein, terms such as first, second, A, B, (a), (b), etc., may be used. These terms are used merely for distinguishing one component from another component and do not limit the component to the essence, sequence, order, etc., of the component. The terms used herein, including technical and scientific terms, have the same meanings as terms that are generally understood by those skilled in the art, as long as the terms are not differently defined. Generally, the terms defined in a generally used dictionary should be interpreted as having the same meanings as the contextual meanings of the relevant technology and should not be interpreted as having ideal or exaggerated meanings unless they are clearly defined in the present document.
Referring to
The battery module 100 may include a plurality of battery banks 110, 120, 130, and 140. Although the plurality of battery banks are illustrated as four in
The battery module 100 may supply power to a target device. To this end, the battery module 100 may be electrically connected to the target device. Herein, the target device may include an electrical, electronic, or mechanical device that operates by receiving power from the battery pack 1000 including the plurality of battery banks 110, 120, 130, and 140, and the target device may be, for example, an electric vehicle (EV) or an energy storage system (ESS), but is not limited thereto.
The plurality of battery banks 110, 120, 130, and 140 may include a plurality of battery cells. The battery cell, which is a basic unit of a battery available by charging and discharging electrical energy, may be a lithium ion (Li-ion) battery, an Li-ion polymer battery, a nickel-cadmium (Ni—Cd) battery, a nickel hydrogen (Ni—MH) battery, etc., and are not limited thereto. According to an embodiment, the plurality of battery cells included in each of the plurality of battery banks 110, 120, 130, and 140 may be connected in parallel to each other.
Meanwhile, although one battery module 100 is illustrated in
The battery management apparatus (a battery management system (BMS)) 200 may predict a life (a state of health (SoH)) of the plurality of battery banks 110, 120, 130, and 140 based on temperature and voltage data of the plurality of battery banks 110, 120, 130, and 140. The battery management apparatus 200 may remove noise from battery data of the plurality of battery banks 110, 120, 130, and 140 and predict a life (SoH) of the plurality of battery banks 110, 120, 130, and 140 for each of temperature and charge/discharge rate of a battery based on the noise-removed data.
The battery management apparatus 200 may manage and/or control a state and/or an operation of the battery module 100. For example, the battery management apparatus 200 may manage and/or control the states and/or operations of the plurality of battery banks 110, 120, 130, and 140 included in the battery module 100. The battery management apparatus 200 may manage charging and/or discharging of the battery module 100.
In addition, the battery management apparatus 200 may monitor a voltage, a current, a temperature, etc., of the battery module 100 and/or each of the plurality of battery banks 110, 120, 130, and 140 included in the battery module 100. A sensor or various measurement modules for monitoring performed by the battery management system may be additionally installed in the battery module 100, a charging/discharging path, any position of the battery module 100, etc. The battery management apparatus 200 may calculate a parameter indicating a state of the battery module 100, e.g., a state of charge (SoC), a SoH, etc., based on a measurement value such as monitored voltage, current, temperature, etc.
The battery management apparatus 200 may control an operation of the relay 300. For example, the battery management apparatus 200 may short-circuit the relay 300 to supply power to the target device. The battery management apparatus 200 may short-circuit the relay 300 when a charging device is connected to the battery pack 1000.
The battery management apparatus 200 may calculate a cell balancing time of each of the plurality of battery banks 110, 120, 130, and 140. Herein, the cell balancing time may be defined as a time required for balancing of the battery cell. For example, the battery management apparatus 200 may calculate a cell balancing time based on an SoC, a battery capacity, and a balancing efficiency of each of the plurality of battery banks 110, 120, 130, and 140.
For the plurality of battery banks 110, 120, 130, and 140, as a period of use or the number of times of use increases, a capacity may decrease, internal resistance may increase, and various factors of the battery may change. The battery management apparatus 200 may calculate an impedance of a battery bank based on data of various factors changing with deterioration of the battery.
More specifically, the battery management apparatus 200 may calculate an imaginary value of an impedance of the plurality of battery banks 110, 120, 130, and 140 based on data of various factors changing with deterioration of the plurality of battery banks 110, 120, 130, and 140 to determine whether an abnormal battery cell exists inside the plurality of battery banks 110, 120, 130, and 140.
The imaginary value of the impedance of the battery may be an index indicating whether heat is generated in the battery in an abnormal state when compared to a normal state of the battery bank. The imaginary value of the impedance of the normal battery bank and the imaginary value of the impedance of the abnormal battery bank may be distinguished.
For example, the battery management apparatus 200 may determine whether an abnormal battery cell exists inside the plurality of battery banks 110, 120, 130, and 140 based on a voltage and a current of each of the plurality of battery banks 110, 120, 130, and 140.
Hereinbelow, a configuration and an operation of the battery management apparatus 200 will be described in detail.
Referring to
The switch 210 may be connected to a plurality of battery banks including a plurality of battery cells. The switch 210 may include, for example, a field effect transistor (FET). The switch 210 may receive a control signal for repeatedly turning on and off the switch 210 from the controller 220. The switch 210 may be repeatedly turned on or off based on the control signal received from the controller 220. The switch 210 may be repeatedly turned on or off and deliver a current in an alternating current waveform to the plurality of battery banks 110, 120, 130, and 140.
The first resistor 230 may control a flow of current inside the battery management apparatus 200 to allow an internal circuit of the battery management apparatus 200 to smoothly operate.
The controller 220 may determine whether an abnormal battery cell exists inside the plurality of battery banks 110, 120, 130, and 140 based on battery data of the plurality of battery banks 110, 120, 130, and 140. More specifically, the controller 220 may determine whether a heat-generated battery cell exists inside the plurality of battery banks 110, 120, 130, and 140 based on battery data of the plurality of battery banks 110, 120, 130, and 140.
The controller 220 may generate the control signal for repeatedly turning on and off the switch 210 and apply the control signal to the switch 210. The controller 220 may measure a voltage value and a current value of each of the plurality of battery banks 110, 120, 130, and 140 having received the current in the alternating current waveform based on a switching operation of the switch 210.
More specifically, the controller 220 may measure a current value of each of the plurality of battery banks 110, 120, 130, and 140 by using the shunt resistor 240. Herein, the shunt resistor 240 may be a resistor mainly used for current measurement as a shunt resistor and may have a very low resistance value. The shunt resistor 240 may measure a current value of each of the plurality of battery banks 110, 120, 130, and 140, and the controller 220 may obtain a current value of each of the plurality of battery banks 110, 120, 130, and 140 from the shunt resistor 240.
Referring to
The controller 220 may determine whether a plurality of battery cells included in each of the plurality of battery banks 110, 120, 130, and 140 are abnormal, based on an alternating current impedance of each of the plurality of battery banks 110, 120, 130, and 140 calculated based on a voltage value and a current value of each of the plurality of battery banks 110, 120, 130, and 140.
Referring to
Referring to
In the RLC current circuit, the Ohm's Law is ‘V=I*R’, and when the Ohm's Law is extended to an alternating current circuit, it may be used as ‘V=I*Z’ or ‘Z=V/I’. Herein, ‘V’ means a voltage, ‘I’ means a current, ‘R’ means a resistance, and ‘Z’ means an impedance. The impedance is a value that disturbs the flow of current when a voltage is applied to a circuit. The impedance value may be indicated by a ratio of a voltage V to a current I of an alternating current circuit in which the impedance has a value of a phase unlike a resistor used in the direct current circuit.
The controller 220 may separately calculate a real value and an imaginary value of an impedance of the plurality of battery banks 110, 120, 130, and 140 with respect to a change in a time frequency by inputting, to an equation ‘Z=V/I’, a real value and an imaginary value of a voltage value V and a current value I of each of the plurality of battery banks 110, 120, 130, and 140 with respect to a change in a time frequency. The imaginary value of the impedance of the plurality of battery banks 110, 120, 130, and 140 may change with a temperature of the battery bank. The imaginary value of the impedance of the battery bank may have a constant value in spite of the change in the time frequency, but may change with the temperature.
More specifically, the graph shown in
In
Referring to
For example, according to an embodiment, when the imaginary value of the impedance of any one of the plurality of battery banks 110, 120, 130, and 140 exceeds a previously stored threshold value, the controller 220 may determine that a heat-generated battery cell exists in at least any one of battery cells inside any one of the plurality of battery banks 110, 120, 130, and 140.
In addition, according to an embodiment, when the imaginary value of the impedance of any one of the plurality of battery banks 110, 120, 130, and 140 falls out of a threshold error range of an imaginary value of an impedance of another battery bank connected in series, the controller 220 may determine that a heat-generated battery cell exists in at least any one of battery cells inside any one of the plurality of battery banks 110, 120, 130, and 140.
As described above, the battery management apparatus 200 according to an embodiment disclosed herein may determine whether an abnormal battery cell exists inside a battery bank based on an impedance of the battery bank measured by a current and a voltage of the battery bank.
The battery management apparatus 200 may previously detect an abnormal battery cell inside a battery bank during an operation of the battery bank to prevent thermal runaway of the battery bank in advance.
When the abnormal battery cell is detected using a direct current resistance meter of an existing battery bank, the battery bank needs to be charged and discharged with a large current of 1C or more, a large equipment such as a cycler that is a large-size current charger is required, but the battery management apparatus 200 may generate an alternating current waveform through switching and apply the alternating current waveform to the battery bank, removing a need for a large-size equipment and thus reducing a cost.
Referring to
In operation S101, the switch 210 may receive a control signal for repeatedly turning on and off the switch 210 from the controller 220. Herein, the switch 210 may be connected to a plurality of battery banks including a plurality of battery cells. The switch 210 may include, for example, an FET.
In operation S101, the switch 210 may be repeatedly turned on or off based on the control signal received from the controller 220. The switch 210 may be repeatedly turned on or off and deliver a current in an alternating current waveform to the plurality of battery banks 110, 120, 130, and 140.
In operation S101, the controller 220 may generate the control signal for repeatedly turning on and off the switch 210 and apply the control signal to the switch 210.
In operation S102, the controller 220 may measure a voltage value and a current value of each of the plurality of battery banks 110, 120, 130, and 140 having received the current in the alternating current waveform based on a switching operation of the switch 210.
In operation S103, the controller 220 may perform Fourier transform on a voltage value and a current value of each of the plurality of battery banks 110, 120, 130, and 140 to obtain a real value and an imaginary value of the voltage value and the current value of each of the plurality of battery banks 110, 120, 130, and 140. Herein, Fourier transform may mean transform to decompose a function with respect to time or space into a time or space frequency component.
In operation S103, the controller 220 may decompose a voltage value and a current value of each of the plurality of battery banks 110, 120, 130, and 140 over time into a time frequency component to convert the same into a complex number including a real value and an imaginary value. In operation S103, that is, the controller 220 may derive a waveform of a real value and an imaginary value of a voltage value and a current value of each of the plurality of battery banks 110, 120, 130, and 140 over time.
In operation S103, the controller 220 may obtain an imaginary value of an impedance of each of the plurality of battery banks 110, 120, 130, and 140 based on a real value and an imaginary value of a voltage value and a current value of each of the plurality of battery banks 110, 120, 130, and 140. In operation S103, the controller 220 may calculate an impedance based on the Ohm's Law used in the RLC current circuit. In operation S103, the controller 220 may calculate a real value and an imaginary value of an impedance of each of a plurality of battery cells inside the plurality of battery banks 110, 120, 130, and 140 with respect to a change in a time frequency by inputting, to the equation ‘Z=V/I’, a real value and an imaginary value of a voltage value V and a current value I of each of the plurality of battery cells inside the plurality of battery banks 110, 120, 130, and 140 with respect to a change in a time frequency.
In operation S104, the controller 220 may diagnose a temperature change of a plurality of battery cells from a change of an imaginary value of an impedance of a plurality of battery cells. The imaginary value of the alternating current impedance when heat generation occurs in one or more battery cell inside the battery bank may be distinguished from an imaginary value of an alternating current impedance of a battery bank including normal battery cells.
In operation S104, the controller 220 may determine that heat generation occurs in any one of the plurality of battery cells inside the battery bank based on the imaginary value of the impedance of the battery bank.
In operation S104, for example, according to an embodiment, when the imaginary value of the impedance of any one of the plurality of battery banks 110, 120, 130, and 140 exceeds a previously stored threshold value, the controller 220 may determine that a heat-generated battery cell exists in at least any one of battery cells inside any one of the plurality of battery banks 110, 120, 130, and 140.
In operation S104, in addition, according to an embodiment, when the imaginary value of the impedance of any one of the plurality of battery banks 110, 120, 130, and 140 falls out of a threshold error range of an imaginary value of an impedance of another battery bank connected in series, the controller 220 may determine that a heat-generated battery cell exists in at least any one of battery cells inside any one of the plurality of battery banks 110, 120, 130, and 140.
Referring to
The MCU 2100 may be a processor that executes various programs (e.g., an impedance calculation program of a battery bank, etc.) stored in the memory 2200, processes various data through these programs, and perform the above-described functions of the battery management apparatus 200 shown in
The memory 2200 may store various programs regarding operations of the battery management apparatus 200. Moreover, the memory 2200 may store operation data of the battery management apparatus 200.
The memory 2200 may be provided in plural, depending on a need. The memory 2200 may be volatile memory or non-volatile memory. For the memory 2200 as the volatile memory, random access memory (RAM), dynamic RAM (DRAM), static RAM (SRAM), etc., may be used. For the memory 2200 as the nonvolatile memory, read only memory (ROM), programmable ROM (PROM), electrically alterable ROM (EAROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), flash memory, etc., may be used. The above-listed examples of the memory 2200 are merely examples and are not limited thereto.
The input/output I/F 2300 may provide an interface for transmitting and receiving data by connecting an input device such as a keyboard, a mouse, a touch panel, etc., and an output device such as a display, etc., to the MCU 2100.
The communication I/F 2400, which is a component capable of transmitting and receiving various data to and from a server, may be various devices capable of supporting wired or wireless communication. For example, a program for resistance measurement and abnormality diagnosis of the battery cell or various data may be transmitted and received to and from a separately provided external server through the communication I/F 2400.
The above description is merely illustrative of the technical idea of the present disclosure, and various modifications and variations will be possible without departing from the essential characteristics of the present disclosure by those of ordinary skill in the art to which the present disclosure pertains.
Therefore, the embodiments disclosed in the present disclosure are intended for description rather than limitation of the technical spirit of the present disclosure and the scope of the technical spirit of the present disclosure is not limited by these embodiments. The protection scope of the present disclosure should be interpreted by the following claims, and all technical spirits within the same range should be understood to be included in the range of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0064229 | May 2022 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2023/006433 | 5/11/2023 | WO |
