CN113805067A - System and method for detecting battery pack parameters - Google Patents
System and method for detecting battery pack parameters Download PDFInfo
- Publication number
- CN113805067A CN113805067A CN202111143194.7A CN202111143194A CN113805067A CN 113805067 A CN113805067 A CN 113805067A CN 202111143194 A CN202111143194 A CN 202111143194A CN 113805067 A CN113805067 A CN 113805067A
- Authority
- CN
- China
- Prior art keywords
- battery pack
- switch
- auxiliary unit
- eis
- auxiliary
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 29
- 238000001514 detection method Methods 0.000 claims abstract description 156
- 238000012360 testing method Methods 0.000 claims description 90
- 239000003990 capacitor Substances 0.000 claims description 55
- 230000005284 excitation Effects 0.000 claims description 23
- 238000004146 energy storage Methods 0.000 claims description 11
- 238000007599 discharging Methods 0.000 claims description 8
- 230000000638 stimulation Effects 0.000 claims description 3
- 238000000157 electrochemical-induced impedance spectroscopy Methods 0.000 description 122
- 210000004027 cell Anatomy 0.000 description 19
- 238000010586 diagram Methods 0.000 description 16
- 230000004044 response Effects 0.000 description 12
- 230000002159 abnormal effect Effects 0.000 description 6
- 230000008569 process Effects 0.000 description 5
- 238000001453 impedance spectrum Methods 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 238000009792 diffusion process Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000001629 suppression Effects 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 230000001960 triggered effect Effects 0.000 description 2
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- 230000005856 abnormality Effects 0.000 description 1
- 239000011149 active material Substances 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000010405 anode material Substances 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000010406 cathode material Substances 0.000 description 1
- 210000005056 cell body Anatomy 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002848 electrochemical method Methods 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000004451 qualitative analysis Methods 0.000 description 1
- 238000004445 quantitative analysis Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000010408 sweeping Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/367—Software therefor, e.g. for battery testing using modelling or look-up tables
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/396—Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
Abstract
The invention provides a system and a method for battery pack parameter detection, and relates to the technical field of battery detection. The system for detecting the battery pack parameters comprises a battery pack to be detected, an auxiliary unit, EIS detection equipment and a switch unit; the auxiliary unit is suitable for forming a series system with the battery pack to be tested; the switch unit is used for controlling the current trend; the EIS detection equipment is used for being connected with the auxiliary unit in series and realizing parameter detection of the auxiliary unit, and is also used for being connected with the series system in series and realizing parameter detection of the series system so as to determine equivalent circuit parameters of the battery pack to be detected according to the equivalent circuit parameters of the auxiliary unit and the overall circuit parameters of the series system. The technical scheme of the invention can offset the higher open-circuit voltage of the battery pack to be detected, so that the common EIS detection equipment can detect the equivalent circuit and the parameters of the high-voltage and high-capacity battery pack.
Description
Technical Field
The invention relates to the technical field of battery detection, in particular to a system and a method for detecting battery pack parameters.
Background
Storage batteries and lithium batteries are used as relatively mature energy storage devices and widely applied to the fields of electric energy storage systems, electric automobiles, electric bicycles, consumer electronics products and the like. The detection of cell performance is important in order to characterize the cell characteristics and screen out products with superior performance during use. And eliminating performance degradation or failure products and necessary processes for batch use of the battery cells.
In the existing method, the EIS (electrochemical impedance spectroscopy) test of the battery is mostly realized through the traditional variable-frequency alternating current sinusoidal excitation or the excitation of square waves, step waves and the like, and then the performance and the state of the battery core are evaluated. However, such methods are only suitable for the case of constant low battery pack voltage such as single battery cell, series connection of several battery cells, and the like. In addition, in practical tests, because the open-circuit voltage of the battery pack is high (more than tens of volts), the alternating current ripple output characteristics under the direct current high-voltage condition are difficult to meet by common electrochemical workstations, potentiostats and galvanoscopes, so that the method is difficult to use in the battery pack.
Disclosure of Invention
The invention solves the problem of how to realize the detection of the equivalent circuit and the parameters of the high-voltage and large-capacity battery pack by the common EIS detection equipment.
In order to solve the above problems, the present invention provides a system for battery pack parameter detection, comprising a battery pack to be detected, an auxiliary unit, an EIS detection device and a switch unit; the auxiliary unit is suitable for forming a series system with the battery pack to be tested; the switch unit is used for controlling the current trend so as to realize the parameter detection of the auxiliary unit, the charging of the auxiliary unit and the parameter detection of the series system; the EIS detection equipment is used for being connected with the auxiliary unit in series and realizing parameter detection of the auxiliary unit, and is also used for being connected with the series system in series and realizing parameter detection of the series system so as to determine equivalent circuit parameters of the battery pack to be detected according to the equivalent circuit parameters of the auxiliary unit and the overall circuit parameters of the series system.
According to the system for detecting the battery pack parameters, the higher open-circuit voltage of the battery pack to be detected is counteracted through the reverse serial connection of the charged auxiliary unit and the battery pack to be detected, the requirement of the EIS detection equipment on the test voltage during the test of the battery pack to be detected is lowered, the parameter requirement of the EIS detection equipment is lowered, and therefore the common EIS detection equipment can detect the equivalent circuit and the parameters of the battery pack with high voltage and high capacity.
Optionally, the switch unit includes first switch, second switch, third switch and fourth switch, the both ends of first switch respectively with the positive pole of the group battery that awaits measuring reaches the one end of auxiliary unit is connected, the one end of second switch is connected first switch with the junction of auxiliary unit, the other end of second switch is connected the group battery that awaits measuring with the junction of EIS check out test set, the both ends of third switch respectively with the other end of auxiliary unit reaches EIS check out test set connects, the one end of fourth switch is connected the auxiliary unit with the junction of third switch, the other end of fourth switch is connected the group battery that awaits measuring with the junction of EIS check out test set.
According to the system for detecting the battery pack parameters, the switch unit comprises the first switch, the second switch, the third switch and the fourth switch, the equivalent circuit parameters of the auxiliary unit detected by the EIS detection equipment, the charging of the auxiliary unit by the battery pack to be detected and the overall circuit parameters of the series system detected by the EIS detection equipment are sequentially realized by the opening and closing of the first switch, the second switch, the third switch and the fourth switch, and further the parameter detection of the battery pack to be detected is realized.
Optionally, the system for battery pack equivalent circuit parameter detection further comprises a flow choke unit connected with the fourth switch for limiting current when the auxiliary unit is charged and as a discharging load when the auxiliary unit is discharged.
The system for detecting the parameters of the battery pack realizes the protection of a circuit by arranging the current-suppressing unit to limit the current when the auxiliary unit is charged and to be used as a discharging load when the auxiliary unit is discharged.
Optionally, the EIS detection apparatus comprises an electrochemical workstation, a combination FRA combined potentiostat-galvanostat apparatus, or a voltage, current source system capable of achieving EIS test ac output stimulation.
The system for detecting the battery pack parameters reduces the requirement of the EIS detection equipment on the test voltage during the test of the battery pack to be detected by setting the specific type of the EIS detection equipment and the circuit setting of the parameter detection system, so that the common EIS detection equipment can detect the equivalent circuit and the parameters of the high-voltage and high-capacity battery pack.
Optionally, the auxiliary unit is an auxiliary capacitor or an auxiliary battery pack, the auxiliary capacitor includes a passive energy storage capacitor with known parameters, and the auxiliary battery pack includes an energy storage battery with known parameters and matched with the open-circuit voltage of the battery pack to be tested.
According to the system for battery pack parameter detection, the higher open-circuit voltage of the battery pack to be detected is counteracted through the charged auxiliary capacitor or the auxiliary battery pack and the battery pack to be detected in reverse series connection, the requirement of EIS detection equipment on the test voltage during the test of the battery pack to be detected is lowered, the parameter requirement of the EIS detection equipment is lowered, and therefore the common EIS detection equipment can detect the equivalent circuit and the parameters of the high-voltage and high-capacity battery pack.
The invention also provides a method for detecting battery pack parameters, which is applied to the system for detecting battery pack parameters and comprises the following steps: after detecting equivalent circuit parameters of an auxiliary unit through EIS detection equipment, connecting the auxiliary unit and a battery pack to be detected in series to form a series system; after the auxiliary unit is charged by the battery pack to be tested, detecting the whole circuit parameters of the series system by the EIS detection equipment; and determining the equivalent circuit parameters of the battery pack to be tested according to the equivalent circuit parameters of the auxiliary unit and the overall circuit parameters of the series system.
According to the method for detecting the parameters of the battery pack, the higher open-circuit voltage of the battery pack to be detected is counteracted through the reverse serial connection of the charged auxiliary unit and the battery pack to be detected, the requirement of the EIS detection equipment on the test voltage during the test of the battery pack to be detected is lowered, the parameter requirement of the EIS detection equipment is lowered, and therefore the common EIS detection equipment can detect the equivalent circuit and the parameters of the battery pack with high voltage and high capacity.
Optionally, the switch unit comprises a first switch, a second switch, a third switch and a fourth switch; after EIS check out test set detects the equivalent circuit parameter of auxiliary unit, will auxiliary unit and the group battery that awaits measuring establish ties and constitute series system and include: opening the first switch and the fourth switch, and closing the second switch and the third switch, so that the EIS detection equipment and the auxiliary unit form a loop to detect the equivalent circuit parameters of the auxiliary unit through the EIS detection equipment; and disconnecting the second switch and the third switch, and closing the first switch and the fourth switch to enable the battery pack to be tested and the auxiliary unit to form a loop so as to charge the auxiliary unit through the battery pack to be tested.
According to the method for detecting the parameters of the battery pack, the equivalent circuit parameters of the auxiliary unit detected by the EIS detection equipment are realized by opening and closing the first switch, the second switch, the third switch and the fourth switch, the battery pack to be detected is charged to the auxiliary unit, and the parameter detection of the battery pack to be detected can be further realized.
Optionally, after the auxiliary unit is charged by the battery pack to be tested, the detecting, by the EIS detecting device, the overall circuit parameter of the series system includes: opening the second switch and the fourth switch, and closing the first switch and the third switch, so that the EIS detection equipment and the series system form a loop to complete EIS test of the series system through the EIS detection equipment; opening the first switch and the third switch, closing the second switch and the fourth switch, such that the auxiliary unit forms a loop with a flow containment unit to enable self-discharge of the auxiliary unit; and setting a circuit model of the series system by combining the circuit model of the auxiliary unit, and analyzing and fitting the whole circuit parameters of the series system.
According to the method for detecting the parameters of the battery pack, the EIS detection equipment is used for detecting the overall circuit parameters of the series system by opening and closing the first switch, the second switch, the third switch and the fourth switch, so that the parameter detection of the battery pack to be detected can be realized.
Optionally, the performing, by the EIS detection apparatus, the EIS test of the series system includes: an alternating current of variable frequency is selected as the excitation current for the EIS detection apparatus.
According to the method for detecting the battery pack parameters, the alternating current with variable frequency is selected as the excitation current of the EIS detection equipment, so that the high-precision detection of the response voltage is facilitated, and the precision of the test result is improved.
Optionally, the determining the equivalent circuit parameter of the battery pack to be tested according to the equivalent circuit parameter of the auxiliary unit and the overall circuit parameter of the series system includes: and eliminating the equivalent circuit parameters of the auxiliary unit from the overall circuit parameters of the series system to determine the equivalent circuit parameters of the battery pack to be tested.
The method for detecting the parameters of the battery pack eliminates the equivalent circuit parameters of the auxiliary unit from the overall circuit parameters of the series system to determine the equivalent circuit parameters of the battery pack to be detected, thereby realizing the parameter detection of the battery pack to be detected.
Drawings
FIG. 1 is a schematic diagram of a system for battery pack parameter detection according to an embodiment of the present invention;
FIG. 2 is an equivalent circuit model of a single cell and battery pack of an embodiment of the present invention;
FIG. 3 is a schematic diagram of a single cell and a battery pack according to an embodiment of the invention, illustrating a Nyquist diagram of an EIS test;
FIG. 4 is a schematic diagram of a circuit configuration for battery pack parameter detection according to an embodiment of the present invention;
FIG. 5 is a series connection of a capacitor to a battery in a system for battery parameter detection according to an embodiment of the present invention;
fig. 6 is a first schematic diagram of an EIS test of a system for battery parameter detection according to an embodiment of the present invention;
fig. 7 is a schematic diagram of the overall structure of a system for battery pack parameter detection according to an embodiment of the present invention;
FIG. 8 is a flowchart of a method for battery pack parameter detection according to an embodiment of the present invention;
fig. 9 is a specific implementation step of the method for battery pack parameter detection according to the embodiment of the invention;
fig. 10 is an equivalent circuit model of a battery pack and an auxiliary capacitor connected in series according to an embodiment of the present invention;
FIG. 11 is a terminal voltage waveform of a battery and auxiliary capacitor series system under 10Hz current excitation in accordance with an embodiment of the present invention;
fig. 12 is a schematic diagram of an EIS test of the system for battery parameter detection according to the embodiment of the present invention.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.
As shown in fig. 1, an embodiment of the present invention provides a system for battery pack parameter detection, including a battery pack to be detected, an auxiliary unit, an EIS detection device, and a switch unit; the auxiliary unit is suitable for forming a series system with the battery pack to be tested; the switch unit is used for controlling the current trend so as to realize the parameter detection of the auxiliary unit, the charging of the auxiliary unit and the parameter detection of the series system; the EIS detection equipment is used for being connected with the auxiliary unit in series and realizing parameter detection of the auxiliary unit, and is also used for being connected with the series system in series and realizing parameter detection of the series system so as to determine equivalent circuit parameters of the battery pack to be detected according to the equivalent circuit parameters of the auxiliary unit and the overall circuit parameters of the series system.
Specifically, in the present embodiment, the equivalent circuit principle is described with reference to fig. 2 to 7, so as to facilitate the detailed description of the present parameter detection scheme.
The battery pack is generally formed by connecting a plurality of battery cells in series and in parallel, and fig. 2 is an equivalent circuit model of a single battery cell and the battery pack. Wherein, VocOpen circuit voltage, R, for a single cellsIs the ohmic impedance of the cell, RctAnd Q is the charge transfer resistance and capacitance of the battery internal ions at the electrode-electrolyte interface, and W is the Warburg impedance, representing the solid diffusion impedance of the ions embedded inside the active material particles. The circuit model generally characterizes the internal electrochemical behavior of the battery as it is charged and discharged. In the figure RlineThe resistance of the wire when the single core interconnects.
Theoretically, if the parameter consistency of each electric core is completely consistent, the equivalent circuit model of the battery pack is the combination and superposition of the single electric core model. However, due to differences in raw materials and manufacturing processes, the uniformity between cells may not be completely consistent. Fig. 3 is a schematic diagram of Nyquist of EIS testing of the unit cell and the battery pack equivalent circuit (Nyquist diagram). In the figure, an EIS test baud chart is converted into a Nyquist chart, and the waveform of the EIS test baud chart can be divided into three parts, namely ohmic internal resistance (high frequency band), charge transfer (middle frequency band) and ion diffusion (ultra-low frequency band), according to an equivalent circuit of a battery cell. If the cell consistency of the battery pack is very good, the EIS-Nyquist diagram of the battery pack is similar to the single cell diagram. However, when an EIS spectrogram has an additional circular arc shape, the test result shows that the cell body may be abnormal; further, similar distortion may occur in the EIS-Nyquist of the battery pack from an abnormal cell pack string. Although the EIS test of the battery pack represents the overall characteristics of the standard battery pack, in the actual test, because the open-circuit voltage of the battery pack is high (more than tens of volts), the ac ripple output characteristics under the dc high-voltage condition are difficult to satisfy by common electrochemical workstations, potentiostats and galvanostatics, and therefore the method is difficult to use in the battery pack. Therefore, the method for testing the alternating current impedance spectrum of the high-voltage high-capacity battery pack has the advantages of low cost, relatively simple structure and strong practicability, and is suitable for testing the alternating current impedance spectrum of the high-voltage high-capacity battery pack.
Fig. 4 is a schematic diagram of a system (circuit structure) for battery pack parameter detection. The selected auxiliary capacitor is a large-capacity capacitor (bearing battery voltage and presenting stable capacity in a test series system) with equivalent circuit parameters not changing with voltage and test frequency. The auxiliary capacitor is connected in series with the battery pack to be tested, and the battery pack charges the auxiliary capacitor after the switch S1 is closed. Because the charge capacity of the auxiliary capacitor is far smaller than that of the battery pack, the port voltage of the auxiliary capacitor can reach the original open-circuit voltage of the battery pack without influencing the capacity state of the battery pack. Thereafter, the connection of the auxiliary capacitor to the battery pack is adjusted as shown in fig. 5.
In fig. 5, since the auxiliary capacitor is connected in reverse series with the battery pack, the open circuit voltage of the series unit is about 0V. Fig. 6 is a schematic diagram of an EIS test for a battery pack equivalent circuit parameter detection system. Because the voltage of the series system terminal is close to 0V, after the EIS detection equipment is connected with two ends of the unit to be detected, the voltage of the port is close to 0V at the moment when the EIS detection equipment carries out testing. When the EIS testing equipment detects the equivalent circuit parameters of a tested system, two excitation modes are generally included: (1) outputting alternating current excitation with variable frequency, and detecting output voltage response; (2) and outputting alternating voltage excitation with variable frequency, and detecting output current response. Because the output instantaneous voltage of the test system is close to 0V, the response caused by the alternating current excitation of the subsequent voltage or current is the characteristic effect caused by the auxiliary capacitor and the battery internal parameter, and the response is within the traditional EIS equipment operation parameter interval, namely the test of the equivalent circuit characteristic parameter of the series unit can be realized by utilizing the traditional EIS equipment. Since the current amplitude, which generally causes voltage disturbance of the high-capacity battery pack, is too large, an EIS test system is recommended as an alternating current excitation test mode. The charged passive energy storage capacitor with known parameters is connected with the high-capacity battery pack in series, so that the defect that the output voltage range of the alternating current impedance testing equipment is small is overcome, and the purpose of representing the characteristics of the high-voltage battery pack by using the alternating current impedance tester is achieved.
Fig. 7 is a schematic diagram of the overall structure of the system for battery parameter detection according to the present embodiment, wherein S1, S2, S3 and S4 are switch units, C is an auxiliary capacitor without polarity, and R is a choke unit. As shown in fig. 12, the auxiliary capacitor may be replaced with an auxiliary battery pack. The parameter detection is carried out according to the circuit shown in fig. 7 or fig. 12, the auxiliary unit is suitable for forming a series system with the battery pack to be detected, the switch unit is used for controlling the current trend so as to respectively realize the parameter detection of the auxiliary unit, the charging of the auxiliary unit and the parameter detection of the series system, the EIS detection equipment is connected with the auxiliary unit in series so as to realize the parameter detection of the auxiliary unit, and is connected with the series system in series so as to realize the parameter detection of the series system, and further the equivalent circuit parameter of the battery pack to be detected can be determined according to the equivalent circuit parameter of the auxiliary unit and the whole circuit parameter of the series system. The auxiliary unit (auxiliary capacitor or auxiliary battery pack) reduces the requirement of the test voltage of the EIS detection equipment during the test of the battery pack to be tested, and reduces the parameter requirement of the EIS detection equipment, so that the common EIS detection equipment can detect the equivalent circuit and the parameters of the high-voltage and high-capacity battery pack.
Because the auxiliary capacitor (or the auxiliary battery pack) has lower influence along with frequency and voltage, after the equivalent parameters of the series system are extracted, the equivalent parameters of the amplitude capacitor are removed, and the equivalent circuit and the parameters of the battery pack can be accurately obtained.
In this embodiment, the charged auxiliary unit is connected in series with the battery pack to be tested in the reverse direction to offset the higher open-circuit voltage of the battery pack to be tested, so that the requirement on the test voltage of the EIS detection equipment during the test of the battery pack to be tested is reduced, and the parameter requirement of the EIS detection equipment is reduced, so that the common EIS detection equipment can detect the equivalent circuit and the parameters of the battery pack with high voltage and large capacity.
Optionally, the switch unit includes first switch, second switch, third switch and fourth switch, the both ends of first switch respectively with the positive pole of the group battery that awaits measuring reaches the one end of auxiliary unit is connected, the one end of second switch is connected first switch with the junction of auxiliary unit, the other end of second switch is connected the group battery that awaits measuring with the junction of EIS check out test set, the both ends of third switch respectively with the other end of auxiliary unit reaches EIS check out test set connects, the one end of fourth switch is connected the auxiliary unit with the junction of third switch, the other end of fourth switch is connected the group battery that awaits measuring with the junction of EIS check out test set.
Specifically, in this embodiment, as shown in fig. 7, the switch unit includes a first switch S1, a second switch S2, a third switch S3, and a fourth switch S4, two ends of the first switch are respectively connected to the positive electrode of the battery pack to be tested and one end of the auxiliary unit, one end of the second switch is connected to a connection point of the first switch and the auxiliary unit, the other end of the second switch is connected to a connection point of the battery pack to be tested and the EIS detection device, two ends of the third switch are respectively connected to the other end of the auxiliary unit and the EIS detection device, one end of the fourth switch is connected to a connection point of the auxiliary unit and the third switch, and the other end of the fourth switch is connected to a connection point of the battery pack to be tested and the EIS detection device. The equivalent circuit parameters of the EIS detection equipment for detecting the auxiliary unit, the charging of the battery pack to be detected to the auxiliary unit and the overall circuit parameters of the series system detected by the EIS detection equipment can be sequentially realized through the opening and closing of the first switch S1, the second switch S2, the third switch S3 and the fourth switch S4.
In this embodiment, the switch unit includes a first switch, a second switch, a third switch and a fourth switch, and the equivalent circuit parameters of the auxiliary unit detected by the EIS detection device, the charging of the battery pack to be detected to the auxiliary unit, and the overall circuit parameters of the series system detected by the EIS detection device are sequentially realized by opening and closing the first switch, the second switch, the third switch and the fourth switch, so as to realize the parameter detection of the battery pack to be detected.
Optionally, the system for battery pack equivalent circuit parameter detection further comprises a flow choke unit connected with the fourth switch for limiting current when the auxiliary unit is charged and as a discharging load when the auxiliary unit is discharged.
Specifically, in the present embodiment, as shown in connection with fig. 7, the system for battery pack equivalent circuit parameter detection further includes a flow suppression unit connected to the fourth switch, the flow suppression unit being configured to limit a current when the auxiliary unit is charged (S1 and S4 are closed, S2 and S3 are open) and to serve as a discharging load when the auxiliary unit is discharged (S3 and S1 are open, S2 and S4 are closed), thereby protecting the circuit.
Wherein the current choke unit may be a charging current choke resistor.
The flow stopping unit may be disposed on the fourth switch shown in fig. 7 on a side close to the connection between the battery pack to be tested and the EIS testing apparatus, or may be disposed on the fourth switch on a side close to the connection between the auxiliary unit and the third switch.
In the embodiment, the current-stopping unit is arranged to limit current when the auxiliary unit is charged and serve as a discharging load when the auxiliary unit is discharged, so that the circuit is protected.
Optionally, the EIS detection apparatus comprises an electrochemical workstation, a combination FRA combined potentiostat-galvanostat apparatus, or a voltage, current source system capable of achieving EIS test ac output stimulation.
Specifically, in this embodiment, the EIS testing apparatus may include an electrochemical workstation, a FRA (frequency Response Analysis) combined potentiostat-galvanostat apparatus, or a voltage, current source system that enables EIS testing of ac output stimuli, i.e., a testing apparatus capable of performing EIS directly or indirectly.
Among them, Electrochemical workstation (Electrochemical workstation) is the abbreviation of Electrochemical measurement system, and is the measurement equipment commonly used in Electrochemical research and teaching. It mainly has 2 categories, single-channel workstation and multi-channel workstation, and is applied to biotechnology, qualitative and quantitative analysis of substances, and the like.
In this embodiment, the specific type of the EIS detection device is set, and the circuit setting of the parameter detection system reduces the requirement of the test voltage of the EIS detection device during the test of the battery pack to be tested, so that the common EIS detection device can detect the equivalent circuit and the parameters of the high-voltage and high-capacity battery pack.
Optionally, the auxiliary unit is an auxiliary capacitor or an auxiliary battery pack, the auxiliary capacitor includes a passive energy storage capacitor with known parameters, and the auxiliary battery pack includes an energy storage battery with known parameters and matched with the open-circuit voltage of the battery pack to be tested.
Specifically, in this embodiment, as shown in fig. 6 and 12, the auxiliary unit is an auxiliary capacitor or an auxiliary battery pack, the auxiliary capacitor includes a passive energy storage capacitor with known parameters, and the auxiliary battery pack includes an energy storage battery with known parameters and matched with the open-circuit voltage of the battery pack to be tested.
In this embodiment, the higher open-circuit voltage of the battery pack to be tested is offset by the charged auxiliary capacitor or the auxiliary battery pack and the battery pack to be tested being connected in series in the reverse direction, so that the requirement of the test voltage of the EIS detection equipment during the test of the battery pack to be tested is reduced, and the parameter requirement of the EIS detection equipment is reduced, so that the common EIS detection equipment can detect the equivalent circuit and the parameters of the high-voltage and large-capacity battery pack.
Another embodiment of the present invention provides a method for battery pack parameter detection, which is applied to the above system for battery pack parameter detection, and includes: after detecting equivalent circuit parameters of an auxiliary unit through EIS detection equipment, connecting the auxiliary unit and a battery pack to be detected in series to form a series system; after the auxiliary unit is charged by the battery pack to be tested, detecting the whole circuit parameters of the series system by the EIS detection equipment; and determining the equivalent circuit parameters of the battery pack to be tested according to the equivalent circuit parameters of the auxiliary unit and the overall circuit parameters of the series system.
Specifically, in this embodiment, with reference to fig. 8 and 9, the method for detecting the battery pack parameter specifically includes:
(1) and selecting a proper auxiliary capacitor (or auxiliary battery pack) and building a circuit as shown in fig. 7. And testing the equivalent circuit of the auxiliary capacitor and the parameters thereof by using EIS detection equipment. The high-frequency thin-film capacitor is recommended to have a large capacitance value and a limit withstand voltage exceeding 2 times of an open-circuit voltage of the battery pack, equivalent parameters of the device are very stable under low-frequency, medium-frequency and high-frequency conditions in normal test, and the equivalent parameters of the device are not changed greatly under high and low voltages, so that the test requirements are met.
(2) And closing S1 and S4, keeping S2 and S3 disconnected, charging the auxiliary capacitor C by the battery pack, and waiting for the voltage across the capacitor to be completely stabilized. The auxiliary capacitor is charged and then is connected with the battery pack in series in the reverse direction, so that the higher open-circuit voltage of the battery pack is automatically offset, and the subsequent EIS test equipment can be conveniently detected. In this step, since the capacity of the capacitor body is much smaller than that of the battery pack, the charging energy of the capacitor does not substantially affect the capacity of the battery pack in the initial state. Fig. 10 is an equivalent circuit model of a battery pack and an auxiliary capacitor connected in series under normal conditions.
(3) And keeping the S2 and the S4 to be opened, closing the S1 and the S3, and setting the size and the frequency interval of the excitation current of the EIS detection equipment to finish the EIS test of the auxiliary capacitor and the battery pack series system. Since the capacity of the entire series unit of the battery pack and the auxiliary capacitor is very large, the current response triggered by the voltage disturbance by the EIS is too large. It is generally recommended to use a variable frequency ac current perturbation as the excitation type. FIG. 11 is a waveform of the output voltage response of a battery and auxiliary capacitor series unit under 10Hz current excitation.
The EIS test is to inject excitation with different frequencies into a test system, and extract circuit parameters based on a circuit model after collecting excitation and response signals. In the test of this step, the injection modes with different frequencies can be generally divided into a frequency mixing mode and a frequency sweeping mode, and in principle, both frequency variation modes can be used. It is worth noting that when the frequency sweep mode is selected, due to the characteristics of the test system proposed in this patent, the voltage ripple of the EIS test system is related to the magnitude and frequency of the excitation, i.e. the higher the excitation current frequency, the smaller the response voltage. In order to fully meet the requirement of the output voltage of the EIS test system, the magnitude of the exciting current can be properly reduced in the low-frequency test stage, and the low-frequency output alternating voltage is prevented from exceeding the equipment protection threshold.
(4) After the test is completed, S3 and S1 are opened, S2 and S4 are closed, and the self-discharge of the capacitor is completed.
(5) And setting an integral circuit model of the series unit by combining the circuit model of the auxiliary capacitor, and fitting the integral circuit parameters by using analysis software to obtain the equivalent circuit characteristic parameters of the battery pack to be tested. Since the fitting process of the EIS-Nyquist result of the series connection integral test and the equivalent circuit model is complex, the order of the time constant (τ ═ RC) in the equivalent circuit needs to be determined by combining the circuit model of the battery pack in a good or possibly abnormal state and the number of arcs of Nyquist. In the process, the circuit model composition needs to be tried and properly adjusted for many times, and potential hazards of the battery pack are eliminated according to the judged abnormal result.
The following test results can be selected as criteria for determining the characteristics of the battery pack:
a) when a plurality of circular arcs (more than or equal to 3) appear in the Nyquist diagram obtained by testing, namely the impedance spectrum of the electric double layer, the performance of individual batteries in the battery pack may be degraded, and electrochemical side reactions may be accelerated.
b) When the ohm impedance test result in the Nyquist diagram obtained by the test is larger (the value is larger than the value after the serial-parallel connection of the nominal resistance value of the single-cell specification book), the fact that the individual cell in the battery pack has the abnormality of tearing of a tab, lower conductivity of electrode liquid and the like or the situations of insufficient welding of the aluminum row terminal of the cell, loosening of screws and the like in the battery pack assembling process can be determined.
c) When the straight slope of the ultralow frequency region (warburg) in the Nyquist map obtained through the test is abnormal (deviated from 45 degrees), the possible reason is that the crystal structure of the anode and cathode materials in the individual battery cell is abnormal.
In this embodiment, the charged auxiliary unit is connected in series with the battery pack to be tested in the reverse direction to offset the higher open-circuit voltage of the battery pack to be tested, so that the requirement on the test voltage of the EIS detection equipment during the test of the battery pack to be tested is reduced, and the parameter requirement of the EIS detection equipment is reduced, so that the common EIS detection equipment can detect the equivalent circuit and the parameters of the battery pack with high voltage and large capacity.
Optionally, the switch unit comprises a first switch, a second switch, a third switch and a fourth switch; after EIS check out test set detects the equivalent circuit parameter of auxiliary unit, will auxiliary unit and the group battery that awaits measuring establish ties and constitute series system and include: opening the first switch and the fourth switch, and closing the second switch and the third switch, so that the EIS detection equipment and the auxiliary unit form a loop to detect the equivalent circuit parameters of the auxiliary unit through the EIS detection equipment; and disconnecting the second switch and the third switch, and closing the first switch and the fourth switch to enable the battery pack to be tested and the auxiliary unit to form a loop so as to charge the auxiliary unit through the battery pack to be tested.
Specifically, in this embodiment, after detecting the equivalent circuit parameter of the auxiliary unit through the EIS detection device, the series system of the auxiliary unit and the battery pack to be tested is formed by connecting the auxiliary unit in series, and includes: opening S1 and S4, closing S2 and S3, and testing the equivalent circuit and the parameters of the auxiliary capacitor by using EIS detection equipment; and closing S1 and S4, keeping S2 and S3 disconnected, charging the auxiliary capacitor C by the battery pack, and waiting for the voltage across the capacitor to be completely stabilized. The EIS detection equipment can detect the equivalent circuit parameters of the auxiliary unit and charge the battery pack to be tested to the auxiliary unit sequentially through the opening and closing of the first switch (S1), the second switch (S2), the third switch (S3) and the fourth switch (S4).
In this embodiment, the equivalent circuit parameters of the auxiliary unit detected by the EIS detection device and the charging of the battery pack to be detected to the auxiliary unit are realized by opening and closing the first switch, the second switch, the third switch and the fourth switch, so that the parameter detection of the battery pack to be detected can be realized.
Optionally, after the auxiliary unit is charged by the battery pack to be tested, the detecting, by the EIS detecting device, the overall circuit parameter of the series system includes: opening the second switch and the fourth switch, and closing the first switch and the third switch, so that the EIS detection equipment and the series system form a loop to complete EIS test of the series system through the EIS detection equipment; opening the first switch and the third switch, closing the second switch and the fourth switch, such that the auxiliary unit forms a loop with a flow containment unit to enable self-discharge of the auxiliary unit; and setting a circuit model of the series system by combining the circuit model of the auxiliary unit, and analyzing and fitting the whole circuit parameters of the series system.
Specifically, in this embodiment, after the auxiliary unit is charged by the battery pack to be tested, the detecting, by the EIS detecting device, the overall circuit parameter of the series system includes: keeping the opening of S2 and S4, closing S1 and S3, setting the size and frequency interval of the excitation current of the EIS detection equipment, and completing the EIS test of the auxiliary capacitor and battery pack series system; after the test is finished, opening S3 and S1, closing S2 and S4, and finishing the self-discharge of the capacitor; and setting a circuit model of the whole series unit by combining the circuit model of the auxiliary capacitor, and fitting the whole circuit parameters by using analysis software. The EIS detection equipment can detect the whole circuit parameters of the series system through the opening and closing of the first switch S1, the second switch S2, the third switch S3 and the fourth switch S4.
When the auxiliary unit is the auxiliary battery pack, the self-discharging process can be abandoned according to actual requirements, so that the auxiliary battery pack is in an open circuit state and does not discharge any more after being cut off from the loop, the voltage of the auxiliary battery pack can be kept unchanged, and the auxiliary battery pack is convenient to continue to use later.
In this embodiment, the EIS detection equipment detects the whole circuit parameters of the series system by opening and closing the first switch, the second switch, the third switch and the fourth switch, so that the parameter detection of the battery pack to be detected can be realized.
Optionally, the performing, by the EIS detection apparatus, the EIS test of the series system includes: an alternating current of variable frequency is selected as the excitation current for the EIS detection apparatus.
Specifically, in this embodiment, the performing the EIS test on the series system by the EIS detecting apparatus includes: an alternating current of variable frequency is selected as the excitation current for the EIS detection apparatus. Since the capacity of the entire series system of the battery pack and the auxiliary capacitor is very large, the current response triggered by the voltage disturbance by the EIS is too large, and it is generally recommended to use the variable-frequency alternating current disturbance as the excitation type.
In the embodiment, by selecting the alternating current with variable frequency as the excitation current of the EIS detection equipment, high-precision detection of response voltage is facilitated, and the precision of a test result is improved.
Optionally, the determining the equivalent circuit parameter of the battery pack to be tested according to the equivalent circuit parameter of the auxiliary unit and the overall circuit parameter of the series system includes: and eliminating the equivalent circuit parameters of the auxiliary unit from the overall circuit parameters of the series system to determine the equivalent circuit parameters of the battery pack to be tested.
Specifically, in this embodiment, determining the equivalent circuit parameter of the battery pack to be tested according to the equivalent circuit parameter of the auxiliary unit and the overall circuit parameter of the series system includes: and eliminating the equivalent circuit parameters of the auxiliary unit from the overall circuit parameters of the series system to determine the equivalent circuit parameters of the battery pack to be tested. Because the characteristic parameters of the circuit of the auxiliary capacitor (or the auxiliary battery pack) are known, after the equivalent parameters of the series system are extracted, the equivalent parameters of the amplitude capacitor are removed, and then the equivalent circuit and the parameters of the battery pack can be accurately obtained.
In this embodiment, the equivalent circuit parameters of the auxiliary unit are removed from the overall circuit parameters of the series system to determine the equivalent circuit parameters of the battery pack to be tested, so that the parameter detection of the battery pack to be tested is realized.
Although the present disclosure has been described above, the scope of the present disclosure is not limited thereto. Various changes and modifications may be effected therein by one of ordinary skill in the pertinent art without departing from the spirit and scope of the present disclosure, and these changes and modifications are intended to be within the scope of the present disclosure.
Claims (10)
1. A system for detecting equivalent circuit parameters of a battery pack is characterized by comprising a battery pack to be detected, an auxiliary unit, EIS detection equipment and a switch unit;
the auxiliary unit is suitable for forming a series system with the battery pack to be tested;
the switch unit is used for controlling the current trend so as to realize the parameter detection of the auxiliary unit, the charging of the auxiliary unit and the parameter detection of the series system;
the EIS detection equipment is used for being connected with the auxiliary unit in series and realizing parameter detection of the auxiliary unit, and is also used for being connected with the series system in series and realizing parameter detection of the series system so as to determine equivalent circuit parameters of the battery pack to be detected according to the equivalent circuit parameters of the auxiliary unit and the overall circuit parameters of the series system.
2. The system for battery pack parameter detection according to claim 1, wherein the switch unit includes a first switch, a second switch, a third switch and a fourth switch, two ends of the first switch are respectively connected to the positive electrode of the battery pack to be detected and one end of the auxiliary unit, one end of the second switch is connected to a connection point of the first switch and the auxiliary unit, the other end of the second switch is connected to a connection point of the battery pack to be detected and the EIS detection equipment, two ends of the third switch are respectively connected to the other end of the auxiliary unit and the EIS detection equipment, one end of the fourth switch is connected to a connection point of the auxiliary unit and the third switch, and the other end of the fourth switch is connected to a connection point of the battery pack to be detected and the EIS detection equipment.
3. The system for battery pack parameter detection according to claim 2, further comprising a flow choke unit connected with the fourth switch, the flow choke unit for limiting current when the auxiliary unit is charging and as a discharging load when the auxiliary unit is discharging.
4. The system for battery pack parameter sensing of claim 1, wherein the EIS sensing device comprises an electrochemical workstation, a combination FRA combined with a potentiometer-galvanostat or a voltage, current source system enabling EIS test ac output stimulation.
5. The system for battery pack parameter detection according to any one of claims 1 to 4, wherein the auxiliary unit is an auxiliary capacitor or an auxiliary battery pack, the auxiliary capacitor comprises a passive energy storage capacitor with known parameters, and the auxiliary battery pack comprises an energy storage battery with known parameters and matched with the open circuit voltage of the battery pack to be detected.
6. A method for battery pack parameter detection, applied to the system for battery pack equivalent circuit parameter detection according to any one of claims 1 to 5, comprising:
after detecting equivalent circuit parameters of an auxiliary unit through EIS detection equipment, connecting the auxiliary unit and a battery pack to be detected in series to form a series system;
after the auxiliary unit is charged by the battery pack to be tested, detecting the whole circuit parameters of the series system by the EIS detection equipment;
and determining the equivalent circuit parameters of the battery pack to be tested according to the equivalent circuit parameters of the auxiliary unit and the overall circuit parameters of the series system.
7. The method for battery pack parameter detection according to claim 6, wherein the switching unit comprises a first switch, a second switch, a third switch, and a fourth switch; after EIS check out test set detects the equivalent circuit parameter of auxiliary unit, will auxiliary unit and the group battery that awaits measuring establish ties and constitute series system and include:
opening the first switch and the fourth switch, and closing the second switch and the third switch, so that the EIS detection equipment and the auxiliary unit form a loop to detect the equivalent circuit parameters of the auxiliary unit through the EIS detection equipment;
and disconnecting the second switch and the third switch, and closing the first switch and the fourth switch to enable the battery pack to be tested and the auxiliary unit to form a loop so as to charge the auxiliary unit through the battery pack to be tested.
8. The method for battery pack parameter detection according to claim 7, wherein the detecting the overall circuit parameter of the series system by the EIS detection device after the auxiliary unit is charged by the battery pack under test comprises:
opening the second switch and the fourth switch, and closing the first switch and the third switch, so that the EIS detection equipment and the series system form a loop to complete EIS test of the series system through the EIS detection equipment;
opening the first switch and the third switch, closing the second switch and the fourth switch, such that the auxiliary unit forms a loop with a flow containment unit to enable self-discharge of the auxiliary unit;
and setting a circuit model of the series system by combining the circuit model of the auxiliary unit, and analyzing and fitting the whole circuit parameters of the series system.
9. The method for battery pack parameter sensing of claim 8, wherein said performing an EIS test of the series system with the EIS sensing apparatus comprises:
an alternating current of variable frequency is selected as the excitation current for the EIS detection apparatus.
10. The method for battery pack parameter detection according to claim 6, wherein the determining the equivalent circuit parameters of the battery pack under test according to the equivalent circuit parameters of the auxiliary unit and the overall circuit parameters of the series system comprises:
and eliminating the equivalent circuit parameters of the auxiliary unit from the overall circuit parameters of the series system to determine the equivalent circuit parameters of the battery pack to be tested.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111143194.7A CN113805067A (en) | 2021-09-28 | 2021-09-28 | System and method for detecting battery pack parameters |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111143194.7A CN113805067A (en) | 2021-09-28 | 2021-09-28 | System and method for detecting battery pack parameters |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113805067A true CN113805067A (en) | 2021-12-17 |
Family
ID=78938694
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111143194.7A Pending CN113805067A (en) | 2021-09-28 | 2021-09-28 | System and method for detecting battery pack parameters |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113805067A (en) |
Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030041445A1 (en) * | 2001-09-03 | 2003-03-06 | Jee-Hwan Jang | Method of grouping single cells of power sources to build optimal packs using parameters obtained by analysis of impedance spectrum |
| US20140333317A1 (en) * | 2013-05-08 | 2014-11-13 | GM Global Technology Operations LLC | Battery state estimator combining electrochemical solid-state concentration model with empirical equivalent-circuit model |
| US20160139207A1 (en) * | 2014-11-19 | 2016-05-19 | Denso Corporation | Apparatus for calculating state of charge of storage battery |
| CN107076801A (en) * | 2014-07-25 | 2017-08-18 | 锂平衡公司 | Electrochemical impedance spectroscopy in battery management system |
| CN107176043A (en) * | 2016-03-10 | 2017-09-19 | 福特全球技术公司 | Power capacity for vehicle battery system is estimated |
| CN107359860A (en) * | 2017-06-28 | 2017-11-17 | 河海大学常州校区 | A kind of perovskite solar cell electron lifetime method of testing based on EIS analyses |
| CN107492917A (en) * | 2016-09-28 | 2017-12-19 | 宝沃汽车（中国）有限公司 | Electric quantity balancing method, battery management system and the power electric car of electrokinetic cell |
| JP2018054371A (en) * | 2016-09-27 | 2018-04-05 | 株式会社東芝 | Battery device and method of setting parameter |
| CN109031145A (en) * | 2018-08-10 | 2018-12-18 | 山东大学 | A kind of series-parallel battery pack model and implementation method considering inconsistency |
| CN109760549A (en) * | 2017-11-10 | 2019-05-17 | 通用汽车环球科技运作有限责任公司 | Maximum current for battery pack calculates and power prediction |
| CN110068772A (en) * | 2019-05-06 | 2019-07-30 | 重庆大学 | Based on the charge states of lithium ion battery estimation method for improving fractional model |
| KR20190140782A (en) * | 2018-06-12 | 2019-12-20 | 주식회사 엘지화학 | Battery management system, battery pack including the same, and method for deteriming a failure of current detecting circuit |
| CN112881929A (en) * | 2020-12-30 | 2021-06-01 | 北京交通大学 | Lithium ion battery EIS low-frequency band online measurement method based on step wave |
| CN112924879A (en) * | 2021-01-27 | 2021-06-08 | 武汉昊诚能源科技有限公司 | Battery discharge depth detection method and system |
| CN113433469A (en) * | 2021-06-08 | 2021-09-24 | 上海电力大学 | Method for detecting calendar aging state of lithium ion battery |
-
2021
- 2021-09-28 CN CN202111143194.7A patent/CN113805067A/en active Pending
Patent Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030041445A1 (en) * | 2001-09-03 | 2003-03-06 | Jee-Hwan Jang | Method of grouping single cells of power sources to build optimal packs using parameters obtained by analysis of impedance spectrum |
| US20140333317A1 (en) * | 2013-05-08 | 2014-11-13 | GM Global Technology Operations LLC | Battery state estimator combining electrochemical solid-state concentration model with empirical equivalent-circuit model |
| CN107076801A (en) * | 2014-07-25 | 2017-08-18 | 锂平衡公司 | Electrochemical impedance spectroscopy in battery management system |
| US20160139207A1 (en) * | 2014-11-19 | 2016-05-19 | Denso Corporation | Apparatus for calculating state of charge of storage battery |
| CN107176043A (en) * | 2016-03-10 | 2017-09-19 | 福特全球技术公司 | Power capacity for vehicle battery system is estimated |
| JP2018054371A (en) * | 2016-09-27 | 2018-04-05 | 株式会社東芝 | Battery device and method of setting parameter |
| CN107492917A (en) * | 2016-09-28 | 2017-12-19 | 宝沃汽车（中国）有限公司 | Electric quantity balancing method, battery management system and the power electric car of electrokinetic cell |
| CN107359860A (en) * | 2017-06-28 | 2017-11-17 | 河海大学常州校区 | A kind of perovskite solar cell electron lifetime method of testing based on EIS analyses |
| CN109760549A (en) * | 2017-11-10 | 2019-05-17 | 通用汽车环球科技运作有限责任公司 | Maximum current for battery pack calculates and power prediction |
| KR20190140782A (en) * | 2018-06-12 | 2019-12-20 | 주식회사 엘지화학 | Battery management system, battery pack including the same, and method for deteriming a failure of current detecting circuit |
| CN109031145A (en) * | 2018-08-10 | 2018-12-18 | 山东大学 | A kind of series-parallel battery pack model and implementation method considering inconsistency |
| CN110068772A (en) * | 2019-05-06 | 2019-07-30 | 重庆大学 | Based on the charge states of lithium ion battery estimation method for improving fractional model |
| CN112881929A (en) * | 2020-12-30 | 2021-06-01 | 北京交通大学 | Lithium ion battery EIS low-frequency band online measurement method based on step wave |
| CN112924879A (en) * | 2021-01-27 | 2021-06-08 | 武汉昊诚能源科技有限公司 | Battery discharge depth detection method and system |
| CN113433469A (en) * | 2021-06-08 | 2021-09-24 | 上海电力大学 | Method for detecting calendar aging state of lithium ion battery |
Non-Patent Citations (2)
| Title |
|---|
| TAE-WON NOH; HAE-CHAN HAN; BYOUNG KUK LEE: "An Online State-of-Health Estimation Algorithm for Electric Vehicles through Aging Tendency of Open Circuit Voltage", 2019 10TH INTERNATIONAL CONFERENCE ON POWER ELECTRONICS AND ECCE ASIA (ICPE 2019 - ECCE ASIA) * |
| 杜常清;潘志强;赵奕凡;朱一多;姚华;: "电动汽车车载充电系统研究", 电源技术, no. 06 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Piłatowicz et al. | A critical overview of definitions and determination techniques of the internal resistance using lithium-ion, lead-acid, nickel metal-hydride batteries and electrochemical double-layer capacitors as examples | |
| CN104865536B (en) | A kind of test of performance of lithium ion battery the reason of decay and diagnostic method | |
| CN108511815B (en) | Method and system for evaluating consistency of lithium ion battery | |
| US7541814B2 (en) | Method and device for determining the charge of a battery | |
| US9121909B2 (en) | Method for estimating state-of-charge of lithium ion battery | |
| CN106842059A (en) | Lithium battery both positive and negative polarity electrochemical properties on-line monitoring method based on three electrode measurements | |
| CN111458642A (en) | Nondestructive testing method for lithium separation of lithium ion storage battery | |
| CN111426971A (en) | Method and device for measuring battery internal resistance component | |
| US10236695B2 (en) | Connectivity check between cells and wiring control electronics with only one switch | |
| JP4887581B2 (en) | Battery inspection method and inspection apparatus | |
| Muhammad et al. | Assessment of spent EV batteries for second-life application | |
| CN107677964A (en) | A kind of New energy automobile motor battery simulating test device and method | |
| CN107544032A (en) | A kind of battery bag or battery system electric leakage Abnormal Insulation analysis method | |
| CN109461980A (en) | A kind of impedance monitoring method characterizing SEI film film forming procedure | |
| CN108152750A (en) | The battery charging and discharging parameter identification method and system of a kind of electric vehicle | |
| CN109794439A (en) | A kind of lithium battery performance screening technique | |
| CN107589378A (en) | A kind of battery equalisation device and method | |
| CN108490364A (en) | A kind of lead-acid accumulator monomer consistency test device and method | |
| CN113805067A (en) | System and method for detecting battery pack parameters | |
| CN108923084B (en) | Method for testing current distribution of polar plate of polar group | |
| CN207336641U (en) | A kind of electric car high-voltage isulation detecting system | |
| Oeser | From the production of the single cell to the end of life of the battery module: the development of parameter variation of lithium-ion cells | |
| CN112379271B (en) | Passivation-considered capacity detection method for carbon-coated lithium thionyl chloride battery | |
| CN108646184A (en) | A kind of internal injury detection device and method based on battery discharging embryonic character | |
| Křivík et al. | Impedance Methods for SoC Determination of Lead Acid Battery Cell |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information | ||
| CB02 | Change of applicant information |
Address after: 230088 west side of the second floor of sunshine power R & D building, no.1699 Xiyou Road, high tech Zone, Hefei City, Anhui Province Applicant after: Hengjun Testing Technology Co.,Ltd. Address before: 230088 west side of the second floor of sunshine power R & D building, no.1699 Xiyou Road, high tech Zone, Hefei City, Anhui Province Applicant before: Hefei Hengjun Testing Technology Co.,Ltd. |