Impedance measuring device

Abstract

An impedance measuring device is provided. According to one embodiment of the utility model, the impedance measuring device used for measuring the impedance of the battery unit based on the measured voltage can comprise a pre-charging circuit used for pre-charging the impedance measuring device; a detection unit for detecting a pre-charge voltage of the impedance measurement device; a processor for comparing the pre-charge voltage with a reference voltage; and a voltage generation unit for outputting the measured voltage.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2022-0077856, filed with the Korean Intellectual Property Office on June 24, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The embodiments disclosed herein relate to impedance measuring devices and their operating methods. Background Technology

[0004] Recently, research and development of rechargeable batteries has been actively underway. Rechargeable batteries, as rechargeable / dischargeable batteries, can include all traditional nickel (Ni) / cadmium (Cd) batteries, nickel / metal hydride (MH) batteries, and more recently, lithium-ion batteries. Lithium-ion batteries have a much higher energy density than traditional Ni / Cd and Ni / MH batteries. Furthermore, lithium-ion batteries can be manufactured to be small and lightweight, making them already used as power sources for mobile devices, and recently, their applications have expanded to electric vehicles, attracting attention as a next-generation energy storage medium.

[0005] Electrochemical impedance spectroscopy (EIS) can be used to analyze the state of a battery and detect its operating characteristics over time. EIS can quickly and accurately detect impedance, which is a factor that hinders the transfer of electrical energy when chemical reactions occur at the electrodes within the battery.

[0006] Battery status can be quickly assessed by detecting impedance, and the assessment can be used to check battery quality, predict remaining lifespan, and optimize charging methods corresponding to battery status. Utility Model Content

[0007] Technical issues

[0008] The embodiments disclosed herein aim to provide an impedance measuring device and its operating method that can effectively measure the impedance of a battery cell.

[0009] The embodiments disclosed herein aim to provide an impedance measuring device and its operation method, including a pre-charge circuit for ensuring the stability of the impedance measuring device.

[0010] The embodiments disclosed herein aim to provide an impedance measuring device and its operating method, the impedance measuring device including a detection unit for identifying whether the pre-charge voltage of the impedance measuring device reaches a reference voltage.

[0011] The technical problems of the embodiments disclosed herein are not limited to those described above. Those skilled in the art will clearly understand other unmentioned technical problems through the following description.

[0012] Technical solution

[0013] An impedance measuring device according to an embodiment of the present invention for measuring the impedance of a battery cell based on a measuring voltage includes: a pre-charging circuit configured to pre-charge the impedance measuring device; a detection unit configured to detect the pre-charging voltage of the impedance measuring device; a processor configured to compare the pre-charging voltage with a reference voltage; and a voltage generation unit configured to output the measuring voltage.

[0014] According to an embodiment, the pre-charging circuit can also be configured to pre-charge the impedance measuring device with a DC voltage.

[0015] According to an embodiment, when the pre-charge voltage is greater than or equal to the reference voltage, the processor can also be configured to control the pre-charge circuit to maintain the DC voltage.

[0016] According to an embodiment, when the pre-charge voltage is less than the reference voltage, the processor can also be configured to control the pre-charge circuit to increase the DC voltage.

[0017] According to an embodiment, the detection unit may be an analog-to-digital converter (ADC) that converts the pre-charge voltage into digital code.

[0018] According to the implementation method, the measured voltage can be an AC voltage.

[0019] According to an embodiment, when the pre-charge voltage is greater than or equal to the reference voltage, the processor can also be configured to control the voltage generation unit to output the measured voltage.

[0020] According to an embodiment, when the pre-charge voltage is less than the reference voltage, the processor can also be configured to control the voltage generation unit to avoid outputting the measured voltage.

[0021] According to an embodiment, the reference voltage can be determined based on the voltage of the battery cell and the circuitry of the impedance measuring device.

[0022] According to an embodiment, the detection unit may also be configured to detect the pre-charge voltage at preset time intervals.

[0023] An operation method for an impedance measuring device for measuring the impedance of a battery cell based on a measuring voltage, according to an embodiment of the present invention, includes the following steps: pre-charging the impedance measuring device through a pre-charging circuit; detecting the pre-charging voltage of the impedance measuring device by a detection unit; and comparing the pre-charging voltage with a reference voltage by a processor.

[0024] According to an embodiment, the step of comparing the pre-charge voltage with the reference voltage by the processor may include the following steps: when the pre-charge voltage is greater than or equal to the reference voltage, controlling the voltage generation unit to output the measured voltage; and when the pre-charge voltage is less than the reference voltage, controlling the voltage generation unit to avoid outputting the measured voltage.

[0025] According to an embodiment, the step of precharging the impedance measuring device through the precharging circuit may include the following steps: precharging the impedance measuring device with a DC voltage through the precharging circuit.

[0026] According to an embodiment, the step of comparing the pre-charge voltage with the reference voltage by the processor may include the following steps: when the pre-charge voltage is greater than or equal to the reference voltage, controlling the pre-charge circuit to maintain the DC voltage; and when the pre-charge voltage is less than the reference voltage, controlling the pre-charge circuit to increase the DC voltage.

[0027] According to an embodiment, the step of detecting the pre-charge voltage may include the following steps: converting the pre-charge voltage into a digital code through the detection unit; and sending the digital code to the processor through the detection unit.

[0028] Beneficial effects

[0029] The impedance measurement system and its operating method according to the embodiments disclosed herein can be used to stabilize the impedance measurement device.

[0030] The impedance measuring device according to the embodiments disclosed herein may include a detection unit, which can improve the operating speed of the measuring device.

[0031] The impedance measuring device and its operating method according to the embodiments disclosed herein can diagnose the condition of a battery cell.

[0032] In addition, it can provide various effects that are directly or indirectly recognized from the public. Attached Figure Description

[0033] Figure 1 This is a block diagram of an impedance measuring device according to the embodiments disclosed herein.

[0034] Figure 2 This is a view used to describe the measurement voltage output time of an impedance measuring device according to an embodiment disclosed herein.

[0035] Figure 3 This is a flowchart illustrating the operation method of an impedance measuring device according to an embodiment disclosed herein.

[0036] Figure 4 This is a flowchart illustrating a method for measuring voltage output according to an embodiment disclosed herein.

[0037] Figure 5 This is a flowchart illustrating an operation method of an impedance measuring device according to another embodiment disclosed herein.

[0038] Figure 6 This is a flowchart illustrating a pre-charge voltage detection method according to another embodiment disclosed herein.

[0039] Figure 7 This is a block diagram illustrating the hardware configuration of a computational system for performing an operation method of an impedance measurement device according to an embodiment disclosed herein. Detailed Implementation

[0040] In the following, the embodiments disclosed in this document will be described in detail with reference to the exemplary accompanying drawings. When adding reference numerals to components in each drawing, it should be noted that the same components are given the same reference numerals even when indicating the same components in different drawings. Furthermore, in describing the embodiments disclosed in this document, detailed descriptions of related known configurations or functions will be omitted if it is determined that such detailed descriptions interfere with the understanding of the embodiments disclosed in this document.

[0041] To describe the components of the embodiments disclosed herein, terms such as first, second, A, B, (a), (B), etc., may be used. These terms are used only to distinguish one component from another and do not limit the components to their nature, order, sequence, etc. The terms used herein (including technical and scientific terms) have the same meaning as those commonly understood by those skilled in the art, provided that these terms are not defined differently. Generally, terms defined in a general dictionary should be interpreted as having the same meaning as in the context of the related art and should not be interpreted as having an ideal or exaggerated meaning unless they are explicitly defined in this application.

[0042] Figure 1 This is a block diagram of an impedance measuring device according to the embodiments disclosed herein.

[0043] Reference Figure 1The impedance measuring device 100 according to the embodiments disclosed herein can be connected to the battery pack 200.

[0044] The impedance measurement device 100 may include a processor 110, a pre-charging circuit 120, a detection unit 130, and a voltage generation unit 140.

[0045] Impedance measurement device 100 may include, for example, an electrochemical impedance spectroscopy (EIS) device. The EIS device can measure the AC impedance spectrum of the battery cells 210 included in the battery pack 200 using a non-destructive testing method.

[0046] According to the implementation, by comparing the measured AC impedance spectrum with the equivalent circuit model of the battery cell 210, the impedance measurement device 100 can estimate the degradation and performance of the battery cell 210.

[0047] Impedance measuring device 100 can calculate the AC impedance spectrum of battery cell 210 based on the changes in amplitude and phase of the signal detected from battery pack 200 relative to the frequency variation of the alternating current (AC) power applied to battery pack 200.

[0048] More specifically, the impedance measuring device 100 can apply an AC voltage (measuring voltage) to the battery pack 200 to sense impedance disturbances in the battery cell 210 and calculate the impedance of the battery cell 210 based on the response to the sensed disturbances (information about the impedance of the battery cell). The impedance calculation of the battery cell 210 can be performed by a processor 110 included in the impedance measuring device 100.

[0049] The impedance measuring device 100 can obtain information about the state of the battery cell 210 by calculating the parameters of the equivalent circuit of the battery cell 210 based on the impedance information of the battery cell 210.

[0050] The impedance measuring device 100 can be pre-charged via the pre-charging circuit 120. The impedance measuring device 100 can be pre-charged to a reference voltage via the pre-charging circuit 120. Because the impedance measuring device 100 is pre-charged to the reference voltage, the influence of the circuit structure of the impedance measuring device and the voltage of the battery cell 210 can be reduced during the measurement of the impedance of the battery cell 210. According to the embodiment, the reference voltage can be referred to as the offset voltage.

[0051] More specifically, when the impedance measuring device 100 is precharged to the reference voltage, it can sensitively detect impedance disturbances in the battery cell 210 caused by the measured voltage output by the impedance measuring device 100.

[0052] The processor 110 can control the signals applied to the impedance measuring device 100 and / or the battery pack 200, and perform operations based on data received from the impedance measuring device 100 and / or the battery pack 200. The processor 110 may be, for example, a microcontroller unit (MCU).

[0053] The processor 110 can control the pre-charge circuit 120 to pre-charge the impedance measuring device 100. The processor 110 can compare the pre-charge voltage of the impedance measuring device 100 with a reference voltage to control the state of the pre-charge circuit 120 and / or the voltage generation unit 140.

[0054] When the pre-charge voltage is greater than or equal to the reference voltage, the processor 110 can control the DC voltage output from the pre-charge circuit 120 to remain constant. When the pre-charge voltage is less than the reference voltage, the processor 110 can control the DC voltage output from the pre-charge circuit 120 to increase.

[0055] According to the embodiment, the pre-charge voltage can be the voltage of the impedance measuring device 100 in the pre-charge state. During the pre-charge period, the DC voltage output from the pre-charge circuit 120 can increase over time. When the pre-charge voltage is greater than or equal to the reference voltage, the pre-charge state can end, and the pre-charge circuit 120 can output a DC voltage of a certain amplitude.

[0056] The pre-charge voltage can be detected by the detection unit 130. The detection unit 130 can detect the voltage of the impedance measuring device 100. According to an embodiment, the detection unit 130 can detect the voltage of a storage element included in the impedance measuring device 100, and detect the pre-charge voltage of the impedance measuring device based on the detected voltage. The storage element can be, for example, a capacitor.

[0057] According to one embodiment, the detection unit 130 may be an analog-to-digital converter (ADC) for converting the pre-charge voltage into digital code. The ADC may have excellent operating range, speed, and resolution, and low latency.

[0058] The ADC can send a digital code converted from the precharge voltage to the processor 110. The processor 110 can compare the precharge voltage with a reference voltage based on the received digital code.

[0059] The detection unit 130 can detect the pre-charge voltage of the impedance measuring device 100 at preset intervals. By including the detection unit 130 for detecting the pre-charge voltage at preset intervals, the processor 110 can quickly determine whether the impedance measuring device 100 has reached the reference voltage.

[0060] In other words, by including the detection unit 130, the time required for the impedance measuring device 100 to detect the impedance of the battery cell 210 can be reduced. The detection unit 130 can identify the pre-charge voltage of the impedance measuring device 100, and the detection unit 130 outputs a measurement voltage based on whether the pre-charge voltage reaches the reference voltage, thereby preventing the measurement of the impedance of the battery cell 210 when the pre-charge voltage has not reached the reference voltage.

[0061] When the pre-charge voltage is greater than or equal to the reference voltage, the processor 110 can control the pre-charge circuit 120 to maintain the output voltage and control the voltage generation unit 140 to output the measurement voltage. The measurement voltage output by the voltage generation unit 140 can be a sinusoidal AC voltage with a certain amplitude and period.

[0062] For example, the measured voltage output by the voltage generation unit 140 can be applied to the battery pack 200. The processor 110 can control the frequency of the AC voltage output from the voltage generation unit 140 to receive information about the impedance perturbation of the battery cell relative to the frequency. That is, the voltage generation unit 140 can send the measured voltage to the battery pack 200 and receive information about the impedance of the battery cell 210 from the battery pack 200.

[0063] The battery pack 200 may include at least one battery cell 210. The battery pack 200 may output information about the impedance of the battery cell 210 based on a measured voltage input from the impedance measuring device 100. The impedance measuring device 100 may calculate the impedance of the battery cell 210 based on the information about the impedance of the battery cell 210.

[0064] Figure 2 This is a view used to describe the measurement voltage output time of an impedance measuring device according to an embodiment disclosed herein.

[0065] exist Figure 2 The diagram shows the pre-charge voltage of the impedance measuring device 100 relative to time.

[0066] exist Figure 2 In the graph, the horizontal axis represents time (unit: seconds (S)) and the vertical axis represents voltage (unit: volts (V)).

[0067] Reference Figure 2 The impedance measuring device 100 can be pre-charged to the reference voltage V0 at the first time T0.

[0068] When the detection unit 130 is included, the second time T x This can be the time when the impedance measuring device 100 outputs the measured voltage. When the reference voltage V0 is constant, the second time T... xIt can vary with the amplitude of the DC voltage output through the pre-charge circuit 120, the pre-charge voltage detection period of the detection unit 130, etc.

[0069] Third time T y It can be a preset time, and is set to be longer than the first time T0. According to the implementation method, the first time T0 and the third time T... y The difference between them can be defined as the margin time. When excluding detection unit 130, the third time T... y It can be the time when the impedance measuring device 100 outputs the measured voltage.

[0070] When the detection unit 130 is not included, the processor 110 may not be able to determine whether the impedance measuring device 100 has been charged to the reference voltage V0, and a margin time can be set so that the pre-charge voltage of the impedance measuring device reaches the reference voltage V0. o The measured voltage is then output. As the margin time increases, the time required to detect the impedance of battery cell 210 may increase.

[0071] Second time T x It may be more than the third time T y It is closer to the first time T0.

[0072] Figure 3 This is a flowchart illustrating the operation method of an impedance measuring device according to an embodiment disclosed herein.

[0073] In operation S100, the pre-charge circuit 120 can pre-charge the impedance measuring device 100.

[0074] According to an embodiment, the processor 110 can control the impedance measuring device 100 to precharge the battery cell 210 via the precharge circuit 120 before detecting the impedance of the battery cell 210.

[0075] In operation S200, the detection unit 130 can detect the pre-charge voltage of the impedance measuring device 100.

[0076] The detection unit 130 can detect the pre-charge voltage of the impedance measuring device 100 by detecting the voltage of the storage element included in the impedance measuring device 100.

[0077] The detection unit 130 can repeatedly detect the pre-charge voltage at preset time intervals. By detecting the pre-charge voltage at preset intervals, the processor 110 can quickly determine whether the impedance measuring device 100 has reached the reference voltage.

[0078] In operation S300, processor 110 can compare the precharge voltage with a reference voltage.

[0079] The processor 110 can compare the pre-charge voltage with a reference voltage and control the voltage generation unit 140 to output a measured voltage based on the comparison result. The battery pack 200, having received the measured voltage, can output information about the impedance of the battery cell 210, and the processor 110 can calculate the impedance of the battery cell 210 based on the information about the battery cell's impedance.

[0080] Figure 4 This is a flowchart illustrating a method for measuring voltage output according to an embodiment disclosed herein.

[0081] Reference Figure 4 The method by which processor 110 outputs a measured voltage by comparing a pre-charge voltage with a reference voltage will be described in detail.

[0082] Reference Figure 4 The operation 300a, in which the processor 110 according to another embodiment compares the pre-charge voltage with the reference voltage, will be described in detail.

[0083] In operation S310a, processor 110 can determine whether the pre-charge voltage is greater than or equal to the reference voltage.

[0084] When the pre-charge voltage is less than the reference voltage (not in operation S310a), in operation S320a, the processor 110 can prevent the voltage generation unit 140 from outputting the measurement voltage. When the pre-charge voltage is less than the reference voltage, in operation S100, the processor 110 can control the pre-charge circuit 120 to pre-charge the impedance measuring device 100.

[0085] When the pre-charge voltage is greater than or equal to the reference voltage ("Yes" in operation S310a), in operation S330a, the processor 110 can control the voltage generation unit 140 to output the measurement voltage.

[0086] When the pre-charge voltage is greater than or equal to the reference voltage, the processor 110 can control the voltage generation unit 140 to output a measurement voltage. This measurement voltage can be applied to the battery pack 200. Information about the impedance of the battery cell 210 detected based on the measurement voltage can be sent to the processor 110. The processor 110 can calculate the impedance spectrum of the battery cell based on the received information about its impedance.

[0087] Figure 5 This is a flowchart illustrating an operation method of an impedance measuring device according to another embodiment disclosed herein.

[0088] In operation S100b, the pre-charge circuit 120 can pre-charge the impedance measuring device 100 with a DC voltage.

[0089] When the impedance measuring device 100 is precharged with a DC voltage, a charge can be precharged in the storage element included in the impedance measuring device. When the impedance measuring device 100 is precharged to a reference voltage, distortion of information about the impedance of the battery cell 210 caused by voltage in the circuit structure of the impedance measuring device 100 or the battery cell 210 can be reduced.

[0090] In operation S200b, the detection unit 130 can detect the pre-charge voltage of the impedance measuring device 100. The above operation can be compared with reference to... Figure 3 The descriptions are basically the same.

[0091] The processor 110 can compare the pre-charge voltage detected by the detection unit 130 with a reference voltage. In operation S310b, the processor 110 can determine whether the pre-charge voltage is greater than or equal to the reference voltage.

[0092] When the pre-charge voltage is less than the reference voltage (No in operation S310b), in operation S320b, the processor 110 can control the pre-charge circuit 120 to increase the DC voltage output from the pre-charge circuit 120. When the pre-charge voltage is less than the reference voltage, the voltage can be increased so that the DC voltage applied to the impedance measuring device 100 reaches the reference voltage.

[0093] When the pre-charge voltage is less than the reference voltage, in operation S100b, the processor 110 can repeat operation S100a to allow the pre-charge circuit 120 to control the pre-charge operation with respect to the impedance measuring device 100.

[0094] When the pre-charge voltage is greater than or equal to the reference voltage ("Yes" in operation S310b), in operation S330b, the processor 110 can control the pre-charge circuit 120 to maintain the DC voltage output from the pre-charge circuit 120. When the pre-charge voltage is maintained at or greater than the reference voltage, the processor 110 can output a measurement voltage through the voltage generation unit 140 and measure the impedance of the battery cell 210.

[0095] Figure 6 This is a flowchart illustrating a pre-charge voltage detection method according to another embodiment disclosed herein.

[0096] exist Figure 6 The method for processing the pre-charge voltage detected by the detection unit 130 is shown in detail.

[0097] In operation S210, the detection unit 130 can convert the pre-charge voltage of the impedance measuring device 100 into a digital code.

[0098] In operation S220, the detection unit 130 can send the detected digital code to the processor 110. According to the embodiment, the detection unit 130 can be an ADC, and the processor 110 can easily process the pre-charge voltage by converting the pre-charge voltage into a digital code.

[0099] Figure 7 This is a block diagram illustrating the hardware configuration of a computational system for performing an operation method of an impedance measurement device according to an embodiment disclosed herein.

[0100] Reference Figure 7 The computing system 1000 according to the embodiments disclosed herein may include an MCU 1010, a memory 1020, an input / output I / F 1030, and a communication I / F 1040.

[0101] According to an embodiment, the computing system 1000 may be a system for performing the above-described operations of the impedance measuring device 100 or the battery pack 200.

[0102] MCU 1010 can be a processor that executes various programs stored in memory 1020.

[0103] For example, MCU 1010 may correspond to processor 110. MCU 1010 may be a processor for processing data and / or signals required by the impedance measurement device 100 for management and control.

[0104] In addition, the MCU 1010 can be a processor that regulates the power applied to the battery pack 200 so that the impedance measuring device 100 measures the impedance of the battery pack 200 and performs impedance calculations based on the information output from the battery pack 200.

[0105] The memory 1020 can store various programs required for managing and controlling the impedance measuring device 100 or the battery pack 200. The memory 1020 can also store various programs required for measuring the impedance of the battery pack 200.

[0106] For example, memory 1020 can store various data for each battery pack 200, such as voltage, current, and characteristic value data. Furthermore, memory 1020 can store a program for calculating impedance based on the voltage, current, and characteristic data of each battery pack 200. Multiple memories 1020 can be provided as needed.

[0107] The memory 1020 can be either volatile memory or non-volatile memory. For the memory 1020 as volatile memory, random access memory (RAM), dynamic RAM (DRAM), static RAM (SRAM), etc., can be used. For the memory 1020 as non-volatile memory, read-only memory (ROM), programmable ROM (PROM), electrically variable ROM (EAROM), electrically erasable PROM (EPROM), electrically erasable PROM (EEPROM), flash memory, etc., can be used. The examples of memory 1020 listed above are merely examples and are not limited to these.

[0108] The Input / Output I / F 1030 provides an interface for sending and receiving data by connecting input devices (not shown) such as a keyboard, mouse, touchpad, etc., and output devices such as a display (not shown) to the MCU 1010.

[0109] The Communication I / F 1040 is a component capable of sending and receiving various types of data to and from a server, and can be any device capable of supporting wired or wireless communication. For example, programs for impedance detection of the battery pack 200 or various data can be sent to and received from a separately provided external server via the Communication I / F 1040.

[0110] Therefore, the computer program according to the embodiments disclosed herein can be recorded in memory 1020 and processed by MCU 1010, thereby being implemented to execute... Figures 1 to 6 The module that provides the indicated function.

[0111] The above description is merely an illustration of the technical concept of this disclosure, and various modifications and changes can be made by those skilled in the art without departing from the essential characteristics of the embodiments disclosed herein.

[0112] Therefore, the embodiments disclosed herein are intended to describe, and not limit, the technical spirit of the embodiments disclosed herein, and the scope of the technical spirit of this disclosure is not limited to these embodiments. The scope of protection of the technical spirit disclosed herein should be interpreted by the appended claims, and all technical spirit within the same scope should be understood to be included within the scope of this disclosure.

Claims

1. An impedance measuring device, characterized by, The impedance measurement device is configured to measure an impedance of a battery cell based on a measurement voltage, the impedance measurement device comprising: a pre-charge circuit configured to pre-charge the impedance measurement device; a detection unit configured to detect a pre-charge voltage of the impedance measurement device; a processor configured to compare the pre-charge voltage with a reference voltage; and a voltage generation unit configured to output the measurement voltage.

2. Impedance measuring device according to claim 1, characterized in that The pre-charge circuit is further configured to pre-charge the impedance measurement device with a direct current voltage.

3. Impedance measuring device according to claim 2, characterized in that The processor is further configured to control the pre-charge circuit to maintain the direct current voltage when the pre-charge voltage is greater than or equal to the reference voltage.

4. The impedance measuring device of claim 2, wherein, The processor is further configured to control the pre-charge circuit to increase the direct current voltage when the pre-charge voltage is less than the reference voltage.

5. The impedance measuring device of claim 1, wherein, The detection unit is an analog-to-digital converter (ADC) that converts the pre-charge voltage into a digital code.

6. The impedance measuring device of claim 1, wherein, The measurement voltage is an alternating current voltage.

7. The impedance measuring device of claim 1, wherein, The processor is further configured to control the voltage generation unit to output the measurement voltage when the pre-charge voltage is greater than or equal to the reference voltage.

8. The impedance measuring device of claim 1, wherein, The processor is further configured to control the voltage generation unit to refrain from outputting the measurement voltage when the pre-charge voltage is less than the reference voltage.

9. The impedance measuring device of claim 1, wherein, The reference voltage is determined based on a voltage of the battery cell and a circuit of the impedance measurement device.

10. The impedance measuring device of claim 1, wherein, The detection unit is further configured to detect the pre-charge voltage at a pre-set time interval.

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