Method and device for compensating load current when performing dynamic EIS, and device for estimating state of battery by using same

Abstract

A load current compensation device according to an embodiment may include: a measurement amplifier for outputting a measurement amplification voltage by amplifying a difference in voltages between both ends of a sensing resistor when a battery current output from a battery is applied to the sensing resistor; a reference voltage source for generating a reference voltage; an error amplifier for outputting an error amplification voltage by comparing the reference voltage with the measurement amplification voltage; and a current flow controller for controlling the flow of an EIS current and a compensation current by using the error amplification voltage.

Description

Method and device for compensating load current when performing dynamic EIS, and device for estimating battery state using the same

[0001] The present invention relates to a method and device for compensating load current when performing dynamic EIS and a device for estimating the state of a battery using the same.

[0002] Automobiles powered by internal combustion engines fueled primarily by gasoline or heavy oil have a significant impact on air pollution and other air pollutants. Therefore, significant efforts are being made to develop electric and hybrid vehicles to reduce these emissions.

[0003] Electric vehicles are vehicles that utilize a battery-powered engine, powered by electric energy generated from a battery. These vehicles utilize a battery pack composed of multiple rechargeable secondary cells, resulting in zero exhaust emissions and minimal noise.

[0004] The more batteries are used in electric vehicles, the shorter their lifespan becomes. As battery lifespan declines, the initial capacity cannot be guaranteed and may gradually decline. If capacity continues to decline, it will no longer provide the power, operating time, and stability desired by users, necessitating battery replacement.

[0005] Small devices like mobile phones have batteries that can be easily replaced, or even without prior notice, without significant inconvenience. In contrast, battery replacement in electric vehicles can be time-consuming and costly. Therefore, accurately diagnosing the battery's condition is crucial to determining when to replace it. Furthermore, accurate battery diagnosis is essential for efficient use of battery energy during charging and discharging, and this necessitates EIS technology.

[0006] Meanwhile, Electrochemical Impedance Spectroscopy (EIS) is widely used to diagnose battery condition, estimating the battery's condition by measuring its impedance. Conventional voltage / current / temperature measurements, while simple, have limited diagnostic accuracy. However, EIS is known to offer high diagnostic accuracy because it can isolate and quantify various electrochemical reactions within the battery.

[0007] However, the current EIS technique has the problem of having to disconnect devices connected to the battery, such as motors, air conditioners, chargers, and battery management integrated circuits (BMICs).

[0008] To address this issue, dynamic EIS technology is being studied at the battery experimental level, and its effectiveness is being verified. Dynamic EIS enables EIS measurements under load or charging current conditions. However, existing dynamic EIS technology suffers from a problem of reduced impedance measurement accuracy due to load / charging current fluctuations.

[0009] The problem to be solved by the present invention is to provide a load current compensation device that compensates for the load current of a load connected to a battery when measuring the state of a battery using dynamic EIS, and a battery state measurement device that measures the state of a battery using the load current compensation device.

[0010] However, the problems to be solved by the present invention are not limited to those mentioned above, and other problems to be solved that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention pertains from the description below.

[0011] A load current compensation device according to one embodiment may include: an instrumentation amplifier that amplifies a difference in voltage across a sensing resistor when a battery current output from a battery is applied to the sensing resistor and outputs an instrumentation amplification voltage; a reference voltage source that generates a reference voltage; an error amplifier that compares the reference voltage and the instrumentation amplification voltage and outputs an error amplification voltage; and a current flow controller that controls the flow of an EIS current and a compensation current input from the battery using the error amplification voltage.

[0012] A battery state estimation device for estimating a state of a battery using dynamic EIS according to another embodiment may include: a battery; a load connected to the battery when performing the dynamic EIS and receiving a load current from the battery; and a load current compensation device for determining a compensation current that compensates for the load current and estimating a state of the battery using the compensation current.

[0013] A method for estimating a state of a battery performed by a load current compensation device according to another embodiment may include: measuring a load current before performing dynamic Electrochemical Impedance Spectroscopy (EIS); determining a direct current using the measured load current; measuring the load current in real time while performing the dynamic EIS; determining a compensation current using the direct current and the load current measured in real time; and compensating the load current measured in real time with the compensation current to estimate the state of the battery.

[0014] According to an embodiment of the present invention, when estimating the state of a battery using dynamic EIS, the state of the battery can be estimated more accurately by compensating for the load current.

[0015] In addition, according to an embodiment of the present invention, by determining the value of the compensation current for compensating the load current as the difference between the maximum value of the previously measured load current and the load current measured in real time, the battery current can flow at a constant value regardless of the load current that changes in real time.

[0016] In addition, according to an embodiment of the present invention, cell balancing technology can be implemented without additional cost by modulating the current flowing in the DC-DC converter by adjusting the duty cycle of the DC-DC converter.

[0017] FIG. 1 is a block diagram showing a battery state estimation device according to one embodiment of the present invention.

[0018] FIG. 2 is a circuit diagram for explaining a load current compensation device according to one embodiment of the present invention.

[0019] FIG. 3 is a circuit diagram for explaining a load current compensation device according to another embodiment of the present invention.

[0020] FIG. 4 is a diagram for explaining a method of modulating the input current of a DC-DC converter according to another embodiment of the present invention.

[0021] FIG. 5 is a block diagram illustrating a battery state estimation device according to one embodiment of the present invention.

[0022] FIG. 6 is a flowchart illustrating a method for estimating a battery state performed by a battery state estimation device according to one embodiment of the present invention.

[0023] FIG. 7 shows waveforms of currents and voltages flowing in a battery state estimation device according to one embodiment of the present invention.

[0024] FIG. 8 is a diagram comparing frequency characteristics measured when estimating the state of a battery using a conventional battery state estimation device and frequency characteristics measured when estimating the state of a battery using a battery state estimation device according to one embodiment.

[0025] FIG. 9 is a diagram comparing the output per frequency measured when estimating the state of a battery using a conventional battery state estimation device and the output per frequency measured when estimating the state of a battery using a battery state estimation device according to one embodiment.

[0026] Fig. 10 is a block diagram of a detailed configuration of a battery state estimation device according to one embodiment of the present invention.

[0027] FIG. 11 is a drawing of a battery state estimation device according to one embodiment of the present invention applied to a cell balancing unit in a battery system.

[0028] FIG. 12 is a drawing of a battery state estimation device according to one embodiment of the present invention applied to a battery system.

[0029] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided solely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined solely by the scope of the claims.

[0030] When describing embodiments of the present invention, detailed descriptions of known functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the invention. Furthermore, the terms described below are defined in light of their functions in the embodiments of the present invention and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the overall content of this specification.

[0031] FIG. 1 is a block diagram showing a battery state estimation device according to one embodiment of the present invention.

[0032] Referring to FIG. 1, a battery state estimation device (10) is used to estimate the state of a battery using dynamic EIS (Electrochemical Impedance Spectroscopy), and may include a load current compensation device (100, 100'), an impedance measurement device (200), a battery (300), a load (400), and a sensing resistor (500).

[0033] The load current compensation device (100, 100') estimates the state of the battery (300) when the load (400) is connected using the dynamic EIS technique, and when estimating the state of the battery (300), the load current (I) transmitted to the load (400) according to the operation of the load (400) L) can be compensated for. For this purpose, the load current compensation device (100, 100') compensates for the EIS current (I EIS ) and compensation current (I COMP ) can be entered.

[0034] The impedance measuring device (200) measures the sensing voltage (V) applied to the sensing resistor (500). B -V BS ) can be input to measure the impedance (Z(f)) of the battery (300).

[0035] The battery (300) is a battery current (I B ) can occur.

[0036] According to an embodiment, a load current compensation device (100, 100') may be configured to compensate for the load current (I L ), when compensating for the battery current (I B ) is the direct current (I) described later. DC ) and EIS current (I EIS ) may correspond to the sum of.

[0037] The load (400) is connected to the battery (300) and may include at least one of an air conditioner, a charger, a battery management chip, and a motor. The load (400) receives a load current (I) from the battery (300). L ) can be input and operated. Load current (I L ) may vary depending on the type of device included in the load (400) and the operation of the device included in the load (400).

[0038] FIG. 2 is a circuit diagram for explaining a load current compensation device according to one embodiment of the present invention.

[0039] Referring to FIGS. 1 and 2, the load current compensation device (100) may include an instrumentation amplifier (110), an error amplifier (120), a reference voltage source (130), and a power transistor (140).

[0040] The instrumentation amplifier (110) has negative and positive input terminals connected to both ends of the sensing resistor (500), respectively, to sense the voltage (V B -V BS ) can be amplified. The instrumentation amplifier (110) can amplify the sensing voltage (V B -V BS ) to amplify the measurement amplification voltage (V IA ) can be printed.

[0041] As one end of the sensing resistor (500) connected to the battery (300) is connected to the negative input terminal of the measuring amplifier (110), and the other end of the sensing resistor (500) is connected to the positive input terminal of the measuring amplifier (110), the measuring amplification voltage (V IA ) can have negative values.

[0042] The error amplifier (120) is a reference voltage (V) of a reference voltage source (130). REF ) is input to the positive input terminal, and the measurement amplification voltage (V IA ) is input as a negative input terminal, and the reference voltage (VREF) and the measurement amplification voltage (V IA ) and compare the reference voltage (VREF) and the measurement amplification voltage (V IA ) using the difference between the error amplification voltage (V EA ) can be output. For example, the error amplification voltage (V EA ) is the reference voltage (VREF) and the measurement amplification voltage (V IA ) may correspond to the difference.

[0043] The reference voltage source (130) is a reference voltage (V REF ) can be generated. Reference voltage (V REF ) is the EIS current (I EIS ) can have the same shape (i.e., the same frequency and amplitude). The reference voltage (V REF ) can be divided into a DC component and an AC component forming a sine wave. At this time, the DC component is the load current (I L) is related to the compensation of the load current (I ), and more specifically, the DC component is the load current (I ) L ) used for compensation of direct current (I DC ) may correspond to the voltage to generate the EIS current. In addition, the AC component is used to perform dynamic EIS, and the EIS current (I EIS ) may be related to.

[0044] The power transistor (140) has an error amplification voltage (V) as a gate. EA ) is input, and the current (EIS current (I) flowing in the power transistor (140) EIS ) and compensation current (I COMP )) can be controlled.

[0045] According to the embodiment, the power transistor (140) is an NMOS, and has an error amplification voltage (V EA ) is above a certain threshold voltage, the source and drain are connected (i.e., closed) and the EIS current (I EIS ) and compensation current (I COMP ) flows, and the error amplification voltage (V EA ) is below the threshold voltage, the connection between the source and drain is disconnected (i.e., open), and the EIS current (I EIS ) and compensation current (I COMP ) may not flow.

[0046] At this time, the error amplification voltage (V EA ), depending on the size of the EIS current (I EIS ) and compensation current (I COMP ) can be reduced in the process of passing through the power transistor (140). That is, the power transistor (140) is an error amplification voltage (V EA ), depending on the size of the EIS current (I EIS ) and compensation current (I COMP ) so that the sum of the EIS current (I EIS ) and compensation current (I COMP) can be controlled. Accordingly, the battery current (I) after one loop of the load current compensation device (100) B ) is generated from the battery (300) and the sensing resistance (R S ) when the battery current (I B ) can form a negative feedback loop.

[0047] In the case of static EIS, when estimating the state of the battery (300), the load current (I L ) is 0, and therefore, as the loop is repeated in the negative feedback loop, there is a separate compensation current (I COMP ) is not applied, the battery current (I B ) is the EIS current (I EIS ) can be identical to.

[0048] However, in the case of dynamic EIS, the load current (I L ) exists, the battery current (IB) is equal to the EIS current (I ) even if the loop is repeated. EIS ) cannot be the same as the load current compensation device (100), and therefore, the load current compensation device (100) can compensate for the EIS current (I ) in the power transistor (140). EIS ) with compensation current (I COMP ) by applying the battery current (I B ) is the EIS current (I EIS ) and direct current (I DC ) can be made equal to the sum of

[0049] Here, the direct current (I DC ) is the load current (I L ) may be a current having a direct current value corresponding to the maximum value of the direct current (I). That is, the direct current (I DC ) is the load current (I L ) is detected, the load current (I L ) can be determined as the maximum value.

[0050] Load current (I L) to detect the battery current (I) output from the battery (300) of the battery (300). B ) is applied to the sensing resistor (500), the difference in voltage across the sensing resistor (500) is amplified, so the battery current (I B ) may also play a role in detecting the load current (I ), and at this time, the measurement amplification current corresponding to the output current of the measurement amplifier (110) is the load current (I L ) corresponds to.

[0051] Therefore, when a command to perform dynamic EIS is input, the load current compensation device (100) compensates the load current (I) by increasing the measurement amplification current corresponding to the output current of the measurement amplifier (110) before performing dynamic EIS. L ) is detected as the maximum value of the measurement amplification current (i.e., the load current (I L ) is the maximum value of the direct current (I DC ) can be determined. Afterwards, the load current compensation device (100) determines the DC current (I) when performing dynamic EIS. DC ) and load current (I) detected in real time L ) using the compensation current (I COMP ) is determined, and the determined compensation current (I COMP ) as load current (I L ) can be compensated (removed).

[0052] That is, the compensation current (I COMP ) is a variable load current (I) when estimating the state of the battery (300). L ) to compensate for the direct current (I DC ) and load current (I L ) can be determined by the difference between the load current compensation device (100). Therefore, the load current compensation device (100) is a direct current (I DC ) is determined, the determined direct current (I DC ) and load current (I) detected in real time L ) to compensate for the difference in current (I COMP) is determined, and the EIS current (I EIS ) can be input to the power transistor (140).

[0053] FIG. 3 is a circuit diagram for explaining a load current compensation device according to another embodiment of the present invention.

[0054] FIG. 4 is a diagram for explaining a method of modulating the input current of a DC-DC converter according to another embodiment of the present invention.

[0055] Referring to FIGS. 1 and 3, the load current compensation device (100') may include a measuring amplifier (110), an error amplifier (120), a reference voltage source (130), and a DC-DC converter (150).

[0056] The instrumentation amplifier (110), error amplifier (120), and reference voltage source (130) illustrated in FIG. 3 may be substantially identical to the instrumentation amplifier (110), error amplifier (120), and reference voltage source (130) illustrated in FIG. 2. Therefore, descriptions of the instrumentation amplifier (110), error amplifier (120), and reference voltage source (130) will be omitted.

[0057] The DC-DC converter (150) can modulate the input current (current flowing through the DC-DC converter (150)) by adjusting the duty cycle of the switching signal.

[0058] Referring further to FIG. 4, the input current of the DC-DC converter (150) may increase when the switching signal is 'High', and may decrease when the switching signal is 'Low'. Accordingly, the input current of the DC-DC converter (150) may increase when the time when the switching signal of the DC-DC converter (150) is 'High' is longer than the time when it is 'Low', and may decrease when the time when the switching signal of the DC-DC converter (150) is 'High' is shorter than the time when it is 'Low'. That is, the DC-DC converter (150) controls the switching signal (i.e., controls the duty cycle of the switching signal) so that the input current (e.g., the load current (IL)) is equal to the EIS current (I EIS ) and compensation current (I COMP ) can be modulated to become the sum of the input current.

[0059] According to the embodiment, the DC-DC converter (150) may be configured as a boost converter structure. For example, if the current to be supplied to the battery (300) is less than a preset target value, the error amplifier (120) increases the error amplification voltage (V EA ) increases, and the DC-DC converter (150) can increase the duty cycle of the switching signal. Accordingly, the current (e.g., load current (IL)) input to the DC-DC converter (150) can increase. On the other hand, if the current to be supplied to the battery (300) is greater than a preset target value, the error amplifier (120) increases the error amplification voltage (V EA ) can reduce the duty cycle of the switching signal, and the DC-DC converter (150) can reduce the current (e.g., load current (IL)) input to the DC-DC converter (150) can be reduced. Through this process, the load current (I L ) is the EIS current (I EIS ) and compensation current (I COMP ) can be equal to the sum of

[0060] Due to this, the load current compensation device (100') can implement cell balancing included in an electric vehicle without additional costs such as additional devices. Here, cell balancing refers to adjusting the voltage imbalance between battery cells connected in series within a battery system. Since the imbalance between battery cells affects the battery capacity and lifespan and can cause a fire risk due to overcharging and overdischarging, it is an essential process for both efficiency and safety.

[0061] Meanwhile, the power transistor (140) of FIG. 2 and the DC-DC converter (150) of FIG. 3 are included in the load current compensation device (100 or 100') to compensate for the EIS current (I EIS ) and compensation current (I COMP ) to control the flow of current, and these can be collectively referred to as current flow controllers.

[0062] FIG. 5 is a block diagram illustrating a battery state estimation device according to one embodiment of the present invention.

[0063] Referring to FIGS. 1, 2, 3 and 5, the battery state estimation device (10) is configured to estimate the load current (I L ) is measured, the direct current (I DC ) and determine the direct current (I DC ) using the compensation current (I COMP ), it may further include a processor (20) and a memory (30).

[0064] The processor (20) can control the overall operation of the battery state estimation device (10).

[0065] The processor (20) has a load current (I L ) is the maximum value of the direct current (I DC ) can be determined. In more detail, when a command to perform dynamic EIS is input, the processor (20) determines the load current (I) before performing dynamic EIS. L) and measure the measured load current (I L ) is the maximum value of the direct current (I DC ) can be determined.

[0066] The processor (20) determines the direct current (I DC ) and load current (I) detected in real time L ) using the compensation current (I COMP ) can be determined.

[0067] In more detail, the processor (20) generates a direct current (I DC ) is determined, the dynamic EIS is started, and the load current (I ) is determined during the execution of the dynamic EIS. L ) is measured in real time, and direct current (I DC ) and measured load current (I L ) to compensate for the difference in current (I COMP ) can be determined.

[0068] The memory (30) may include volatile random access memory (RAM), nonvolatile read only memory (ROM), nonvolatile magnetoresistive RAM (MRAM), and / or other types of memory. The memory (30) may include a data storage for storing data (e.g., measured values ​​of load current, determined values ​​of direct current, determined values ​​of compensation current, etc.) and instructions executable by the controller / processor (e.g., instructions for performing processes performed by the battery state estimation device (10) as described herein).

[0069] The data storage may include one or more types of non-volatile storage, such as magnetic storage, optical storage, solid-state storage, etc.

[0070] FIG. 6 is a flowchart illustrating a method for estimating a battery state performed by a battery state estimation device according to one embodiment of the present invention.

[0071] Referring to FIGS. 1 to 6, the battery state estimation device (10) measures the load current (I) before performing dynamic EIS. L ) and measure the measured load current (I L ) using direct current (I DC ) can be determined (S610).

[0072] The battery state estimation device (10) estimates the load current (I) during the performance of dynamic EIS. L ) is measured in real time, and direct current (I DC ) and load current (I) measured in real time L ) using the compensation current (I COMP ) can be determined (S620).

[0073] The load current compensation device (100, 100') compensates the current (I COMP ) measured in real time as load current (I L ) can be compensated for, and the state of the battery (300) can be estimated (S630).

[0074] Fig. 7 shows waveforms of currents and voltages flowing in a battery state estimation device according to one embodiment.

[0075] Referring to FIG. 1, FIG. 2 and FIG. 7, when checking the state of the battery (300) using dynamic EIS, since the state of the battery (300) is checked while the load (400) is connected, the load current (I) transmitted to the load (400) L ) may occur.

[0076] Therefore, when a command to perform dynamic EIS is input, the load current compensation device (100, 100') compensates the load current (I) before performing dynamic EIS. L ) and detect the load current (I L ) is the maximum value of the direct current (IDC ) can be determined.

[0077] Afterwards, when performing dynamic EIS, the load current compensation device (100, 100') compensates for the load current (I L ) is detected in real time and the determined direct current (I DC ) and load current (I) detected in real time L ) to compensate for the difference in current (I COMP ) is determined, and the determined compensation current (I COMP ) using the load current (I L ) can be compensated (removed).

[0078] Therefore, the load current (I L ) changes in real time, the load current (I L ) is removed, so that the battery current (I B ) can flow constantly, and therefore, the battery state estimation device (10) can accurately estimate the state of the battery (300) even though the load (400) is connected.

[0079] FIG. 8 is a diagram comparing frequency characteristics measured when estimating the state of a battery using a conventional battery state estimation device of the present invention and frequency characteristics measured when estimating the state of a battery using a battery state estimation device according to one embodiment.

[0080] Referring to FIGS. 1, 2 and 8, the upper drawing may represent frequency characteristics measured when estimating the state of a battery using a conventional battery state estimation device, and the lower drawing may represent frequency characteristics measured when estimating the state of a battery using a battery state estimation device (10) according to one embodiment.

[0081] As shown in the above drawing, when estimating the state of the battery using the dynamic EIS method using a conventional battery state estimation device, the load current due to the load connected to the battery is not removed, so the frequency (f) of the EIS current for estimating the state of the battery EIS ) In addition, the frequency according to the load's operation can also be measured.

[0082] On the other hand, when estimating the state of the battery by dynamic EIS method using the battery state estimation device (10) according to one embodiment, the load current (I) is compensated by the load current compensation device (100, 100'). L ) is compensated (removed), so the EIS current (I EIS ) of frequency (f EIS ) can be confirmed to be measured.

[0083] Therefore, when estimating the state of the battery by dynamic EIS method using the battery state estimation device (10) according to one embodiment, the load current (I) is compensated by the load current compensation device (100, 100'). L ) is compensated (removed), the state of the battery (300) can be estimated more accurately.

[0084] FIG. 9 is a diagram comparing the output per frequency measured when estimating the state of a battery using a conventional battery state estimation device of the present invention and the output per frequency measured when estimating the state of a battery using a battery state estimation device according to one embodiment.

[0085] Referring to FIGS. 1, 2, 3, and 9, the left drawing may represent the output for each frequency measured when estimating the state of a battery using a conventional battery state estimation device, and the right drawing may represent the output for each frequency measured when estimating the state of a battery using a battery state estimation device (10) according to one embodiment.

[0086] As shown in the left drawing, when the state of the battery is estimated by the dynamic EIS method using a conventional battery state estimation device, the output according to the load current by the load connected to the battery is 9μ[V 2 ], whereas the output for EIS measurement is 0.1μ[V 2 ], the SNDR (Signal-to-Noise-and-Distortion Ratio) is -19 dB.

[0087] On the other hand, when estimating the state of the battery by dynamic EIS method using the battery state estimation device (10) according to one embodiment, the load current (I) is compensated by the load current compensation device (100, 100'). L ) is compensated, the output according to the load current by the load connected to the battery is 0.6p[V 2 ], the SNDR is shown to be 33 dB, and it can be confirmed that an improvement of about 10,000 times has been achieved compared to the conventional battery status estimation device.

[0088] Fig. 10 is a block diagram of a detailed configuration of a battery state estimation device according to one embodiment of the present invention.

[0089] Referring to FIGS. 5 and 10, the battery state estimation device (1000) includes a communication unit (1010), a storage unit (1020), and a processor (1030).

[0090] The communication unit (1010) performs communication. The communication unit (1010) can perform communication with external electronic devices through various communication methods such as BT (Bluetooth), WI-FI (Wireless Fidelity), ZigBee, IR (Infrared), NFC (Near Field Communication), etc.

[0091] The storage unit (1020) can store an O / S (Operating System) software module for driving the battery status estimation device (1000), data for configuring various UI screens provided in the display area, etc. In addition, the storage unit (1020) can be read and written as described above.

[0092] The processor (1030) controls the overall operation of the battery status estimation device (1000) using various programs stored in the storage unit (1020).

[0093] Specifically, the processor (1030) includes a RAM (1031), a ROM (1032), a main CPU (1033), a graphics processing unit (1034), first to n interfaces (1035-1 to 1035-n), and a bus (1036).

[0094] Here, RAM (1031), ROM (1032), main CPU (1033), graphics processing unit (1034), first to nth interfaces (1035-1 to 1035-n), etc. can be connected to each other via a bus (1036).

[0095] The first to nth interfaces (1035-1 to 1035-n) are connected to the various components described above. One of the interfaces may be a network interface that connects to an external device via a network.

[0096] ROM (1032) stores a set of commands for system booting, etc. When a turn-on command is input and power is supplied, the main CPU (1033) copies the O / S stored in the storage unit (1020) to RAM (1031) according to the commands stored in ROM (1032) and executes the O / S to boot the system.

[0097] When booting is complete, the main CPU (1033) copies various stored application programs to RAM (1031) and executes the application programs copied to RAM (1031) to perform various operations.

[0098] The main CPU (1033) accesses the storage (1020) and performs booting using the O / S stored in the storage (1030). In addition, the main CPU (1033) performs various operations using various programs, contents, data, etc. stored in the storage (1030).

[0099] The graphics processing unit (1034) uses the calculation unit and the rendering unit to create a screen including various objects such as icons, images, and text.

[0100] FIG. 11 is a drawing of a battery state estimation device according to one embodiment of the present invention applied to a cell balancing unit in a battery system.

[0101] Referring to FIG. 11, by connecting a load current compensation device (100) according to one embodiment of the present invention to a cell balancing unit (600) within a battery system, the load current compensation device (100) can control the flow of EIS current and compensation current input from the battery and simultaneously operate as a cell balancing unit (600) of the battery system.

[0102] More specifically, a battery generating a voltage higher than the reference cell voltage within the battery system consumes energy as heat in the cell balancing unit (600) to lower the high voltage to the reference cell voltage, and the energy consumed at this time is converted into power transistor (M) in the load current compensation device (100). PT ) can be used to recycle the wasted energy. Here, the reference cell voltage refers to the voltage required for each battery cell within the battery system.

[0103] In addition, the current flow controller of the load current compensation device (100) according to one embodiment of the present invention in FIG. 11 is a power transistor (M PT ) was explained as an example, but it is also possible to implement it with a DC-DC converter.

[0104] FIG. 12 is a drawing of a battery state estimation device according to one embodiment of the present invention applied to a battery system.

[0105] Referring to FIG. 12, a load current compensation device (100) according to one embodiment of the present invention and a high voltage MUX and HVLS (High Voltage Low Shifter) capable of integrated control thereof are added to each battery in the battery system, thereby configuring a feedback circuit that simultaneously performs load current compensation and cell balancing for dynamic EIS in the battery system.

[0106] A battery state estimation device according to one embodiment can be implemented by reusing the cell balancing resistors essential for existing multi-battery systems. This minimizes additional costs for existing multi-battery systems, thereby enabling the implementation of a battery state estimation device according to one embodiment.

[0107] According to an embodiment of the present invention, when estimating the state of a battery using dynamic EIS, the state of the battery can be estimated more accurately by compensating for the load current.

[0108] In addition, according to an embodiment of the present invention, by determining the value of the compensation current for compensating the load current as the difference between the maximum value of the previously measured load current and the load current measured in real time, the battery current can flow at a constant value regardless of the load current that changes in real time.

[0109] In addition, according to an embodiment of the present invention, cell balancing technology can be implemented without additional cost by modulating the current flowing in the DC-DC converter by adjusting the duty cycle of the DC-DC converter.

[0110] The combination of each block of the block diagram and each step of the flowchart attached to the present invention may be performed by computer program instructions. These computer program instructions may be installed in an encoding processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the encoding processor of the computer or other programmable data processing equipment create a means for performing the functions described in each block of the block diagram or each step of the flowchart. These computer program instructions may also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce an article of manufacture that includes an instruction means for performing the functions described in each block of the block diagram or each step of the flowchart. Since the computer program instructions can also be installed on a computer or other programmable data processing device, a series of operational steps are performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for executing the functions described in each block of the block diagram and each step of the flowchart can also provide steps for executing the functions described in each block of the block diagram and each step of the flowchart.

[0111] Additionally, each block or step may represent a module, segment, or portion of code that includes one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative embodiments, the functions mentioned in the blocks or steps may occur out of order. For example, two blocks or steps depicted in succession may actually be performed substantially concurrently, or the blocks or steps may sometimes be performed in reverse order, depending on the functionality they perform.

[0112] The above description is merely an illustrative illustration of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential quality of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate, rather than limit, the technical idea of ​​the present invention, and the scope of the technical idea of ​​the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

Claims

1. An instrumentation amplifier that amplifies the voltage across the sensing resistor when the battery current output from the battery is applied to the sensing resistor and outputs a measurement amplification voltage; A reference voltage source that generates a reference voltage; An error amplifier that compares the reference voltage and the measurement amplification voltage and outputs an error amplification voltage; and A load current compensation device including a current flow controller that controls the flow of EIS current and compensation current input from the battery by using the above error amplification voltage.

2. In paragraph 1, The above current flow controller comprises a power transistor implemented as an NMOS, One end of the above power transistor is connected to one end of the above sensing resistor and the load, A load current compensation device, wherein when estimating the state of the battery by performing dynamic EIS (dynamic Electrochemical Impedance Spectroscopy), the battery current corresponds to the sum of the EIS current, the compensation current, and the load current input to the load.

3. In paragraph 2, A load current compensation device, wherein the above compensation current is the difference between the preset direct current and the above load current.

4. In paragraph 3, The above direct current is, A load current compensation device corresponding to the maximum value of the current input to the load, measured prior to performing the above dynamic EIS.

5. In paragraph 3, The DC component of the above reference voltage is A load current compensation device, which is a voltage corresponding to the above direct current.

6. In paragraph 2, The above power transistor, A load current compensation device that controls the flow of the EIS current and the compensation current when the above error amplification voltage is higher than a predetermined threshold voltage.

7. In paragraph 2, The above EIS current and the above compensation current are, A load current compensation device that is input to the battery after passing through the power transistor during the performance of the above dynamic EIS.

8. In paragraph 1, The above current flow controller includes a DC-DC converter having one end connected to one end of the sensing resistor and a load, The above DC-DC converter, A load current compensation device that modulates the input current by controlling the duty cycle of the switching signal.

9. In paragraph 8, The above DC-DC converter, If the current to be supplied to the battery is less than the preset target value, the duty cycle is increased as the error amplification voltage increases. A load current compensation device that reduces the duty cycle as the error amplification voltage decreases when the current to be supplied to the battery is greater than the target value.

10. In paragraph 1, The above error amplifier is, A load current compensation device that generates the error amplification voltage by using the difference between the reference voltage and the measurement amplification voltage.

11. In a battery state estimation device that estimates the state of a battery using dynamic EIS (dynamic Electrochemical Impedance Spectroscopy), battery; A load connected to the battery and receiving load current from the battery when performing the above dynamic EIS; and A battery state estimation device, comprising a load current compensation device that determines a compensation current that compensates for the load current and estimates the state of the battery using the compensation current.

12. In paragraph 11, The above load current compensation device is, Before performing the above dynamic EIS, the DC current is determined using the current input to the load, A battery state estimation device that determines the compensation current by using the DC current and the load current when performing the above dynamic EIS.

13. In paragraph 12, The above load current compensation device is, A battery condition estimation device that determines the maximum value of the current input to the above load as the DC current.

14. In paragraph 12, The above load current compensation device is, A battery state estimation device that determines the difference between the DC current and the load current as the compensation current.

15. In paragraph 11, Further comprising a sensing resistor connected to one end of the above battery, The above load current compensation device is, An instrumentation amplifier that amplifies the difference in voltage across the sensing resistor and outputs a measurement amplification voltage; A reference voltage source that generates a reference voltage; An error amplifier that compares the reference voltage and the measurement amplification voltage and outputs an error amplification voltage; and A battery state estimation device, comprising a current flow controller that controls the flow of the EIS current and the compensation current input from the battery using the error amplification voltage.

16. In paragraph 15, When performing the above dynamic EIS, the battery current outputted by the battery to the load current compensation device and the load is A battery state estimation device corresponding to the sum of the EIS current, the compensation current, and the load current.

17. In paragraph 15, The above current flow controller comprises a power transistor implemented as an NMOS, The above power transistor, A battery state estimation device that controls the flow of the EIS current and the compensation current when the above error amplification voltage is greater than a predetermined threshold voltage.

18. In paragraph 15, The above current flow controller includes a DC-DC converter having one end connected to one end of the sensing resistor and a load, The above DC-DC converter, A battery state estimation device that modulates input current by controlling the duty cycle of a switching signal.

19. In paragraph 15, The above current flow controller, A battery state estimation device that controls the flow of the compensation current by using the excess of the battery voltage with respect to the reference cell voltage.

20. A method for estimating the state of a battery performed by a load current compensation device, Step of measuring the load current before performing dynamic EIS (dynamic Electrochemical Impedance Spectroscopy); A step of determining a direct current using the measured load current; A step of measuring the load current in real time during the execution of the above dynamic EIS; A step of determining a compensation current using the DC current and the load current measured in real time; and A method for estimating the state of a battery, comprising a step of compensating the load current measured in real time with the compensation current to estimate the state of the battery.

21. In paragraph 20, The step of measuring the above load current is: A method for estimating the state of a battery, comprising the step of measuring a load current when a command to perform the above dynamic EIS is input.

22. In paragraph 20, The step of determining with the above direct current is: A method for estimating the state of a battery, comprising a step of determining the maximum value of the measured load current as a direct current.

23. In paragraph 20, The step of determining the above compensation current is: A method for estimating the state of a battery, comprising a step of determining the difference between the DC current and the load current measured in real time as the compensation current.

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