Impedance measurement method, medium, system, and device

Abstract

An impedance measurement method, a control system, an electrical energy system, a storage medium, a battery management system, and an electrical energy device. The impedance measurement method comprises: on the basis of a target current in a low voltage battery and a target voltage of at least one battery cell, determining impedance information of the at least one battery cell, wherein the target current and the target voltage are the current and the voltage of the at least one battery cell under the action of a preset excitation signal, and the preset excitation signal is generated by a DC-DC converter.

Description

Impedance measurement method, medium, system and equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to Chinese patent application number 202410385088.7, filed with the China Patent Office on March 29, 2024, entitled “Impedance Measurement Method, Medium, System and Device for Low-Voltage Batteries,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the field of battery technology, and in particular to an impedance measurement method, a control system, an electric energy system, a storage medium, a battery management system, and an electric energy device. Background Art

[0004] The cell impedance of a low-voltage battery reflects the internal electrochemical characteristics of the cell and is of great significance in research, analysis, and practical applications. For example, by measuring the cell impedance of a low-voltage battery and constructing an electrochemical impedance spectroscopy (EIS), high-precision low-voltage battery state estimation can be achieved through EIS, which provides insights into the battery mechanism.

[0005] However, low-voltage batteries are passive energy sources. In related technologies, the cell impedance of low-voltage batteries can only be measured in a laboratory environment using an electrochemical workstation to generate an excitation signal source, which makes the measurement difficult. Summary of the Invention

[0006] The purpose of the present disclosure is to provide an impedance measurement method, a control system, an electric energy system, a storage medium, a battery management system and an electric energy device. According to the target current in the low-voltage battery and the target voltage of the at least one battery cell, the impedance information of the at least one battery cell can be determined. Since the target current and the target voltage are the current and voltage of the at least one battery cell under the action of a preset excitation signal, and the preset excitation signal is generated by the DC-DC converter, the measurement of the impedance of the low-voltage battery is realized without an electrochemical workstation.

[0007] To achieve the above objectives, according to a first aspect of the present disclosure, there is provided an impedance measurement method, which is applied to a control system connected to a low-voltage battery, wherein the low-voltage battery includes at least one battery cell and is connected to a high-voltage battery via a DC-DC converter. The method comprises:

[0008] The impedance information of the at least one battery cell is determined based on the target current in the low-voltage battery and the target voltage of the at least one battery cell; wherein the target current and the target voltage are the current and voltage of the at least one battery cell under the action of a preset excitation signal, and the preset excitation signal is generated by the DC-DC converter, and the preset excitation signal is used to control the low-voltage battery to discharge to the high-voltage battery through the DC-DC converter, or to control the high-voltage battery to discharge to the low-voltage battery through the DC-DC converter.

[0009] Optionally, the method further includes:

[0010] Determine the frequency point to be measured corresponding to the low-voltage battery;

[0011] For any one or more of the frequency points to be measured, generating a corresponding first request according to the one or more frequency points to be measured, wherein the first request is used to control the DC-DC converter to generate the preset excitation signal corresponding to the one or more frequency points to be measured;

[0012] The determining the impedance information of the at least one battery cell according to the target current in the low-voltage battery and the target voltage of the at least one battery cell includes:

[0013] The impedance information of the at least one battery cell is determined according to the target current corresponding to all the frequency points to be measured and the target voltage of the at least one battery cell.

[0014] Optionally, the preset excitation signal is a current signal, the current signal includes an alternating current component, and the alternating current component is an alternating current signal with multiple frequency points superimposed.

[0015] Optionally, determining the impedance information of the at least one battery cell according to the target current in the low-voltage battery and the target voltage of the at least one battery cell includes:

[0016] The impedance information of the at least one battery cell is determined according to the target current of the low-voltage battery at the multiple acquisition moments and the target voltage of the at least one battery cell at the multiple acquisition moments.

[0017] Optionally, the impedance information includes electrochemical impedance spectroscopy.

[0018] Optionally, the control system is connected to the DC-DC converter, and the method further comprises:

[0019] A first request is sent to the DC-DC converter, where the first request is used to control the DC-DC converter to generate the preset excitation signal.

[0020] Optionally, sending a first request to the DC-DC converter includes:

[0021] In response to determining that a preset condition is satisfied, the first request is sent to the DC-DC converter.

[0022] According to a second aspect of the present disclosure, a control system is provided, which is used to cooperate with a low-voltage battery, a high-voltage battery and a DC-DC converter. The low-voltage battery includes at least one battery cell, and the low-voltage battery is connected to the high-voltage battery through a DC-DC converter. The control system is used to implement the method described in the first aspect.

[0023] According to a third aspect of the present disclosure, an electric energy system is provided, comprising a low-voltage battery, a high-voltage battery, a DC-DC converter and a control system, wherein the low-voltage battery comprises at least one battery cell, and the low-voltage battery is connected to the high-voltage battery via a DC-DC converter, and the control system is the control system described in the second aspect.

[0024] According to a fourth aspect of the present disclosure, an impedance measurement method is provided, which is applied to an electric energy device, wherein the electric energy device includes a low-voltage battery, a high-voltage battery, a DC-DC converter, and a control system connected to the low-voltage battery, wherein the low-voltage battery includes at least one battery cell and is connected to the high-voltage battery via the DC-DC converter. The method includes:

[0025] generating a preset excitation signal through the DC-DC converter, wherein the preset excitation signal is used to control the low-voltage battery to discharge to the high-voltage battery through the DC-DC converter, or to control the high-voltage battery to discharge to the low-voltage battery through the DC-DC converter;

[0026] The control system determines the impedance information of the at least one battery cell based on the target current in the low-voltage battery and the target voltage of the at least one battery cell; wherein the target current and the target voltage are the current and voltage of the at least one battery cell under the action of a preset excitation signal.

[0027] According to a fifth aspect of the present disclosure, a non-transitory computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the impedance measurement method described in the first aspect of the present disclosure are implemented.

[0028] According to a sixth aspect of an embodiment of the present disclosure, there is provided a battery management system, including:

[0029] a non-volatile memory for storing computer programs executable by the processor;

[0030] The processor is used to execute a computer program to implement the steps of the impedance measurement method described in the first aspect of the present disclosure.

[0031] According to a seventh aspect of an embodiment of the present disclosure, there is provided an electric energy device, comprising the battery management system described in the sixth aspect of the present disclosure.

[0032] Through the above technical solution, the impedance information of the at least one battery cell can be determined according to the target current in the low-voltage battery and the target voltage of the at least one battery cell. Since the target current and the target voltage are the current and voltage of the at least one battery cell under the action of a preset excitation signal, and the preset excitation signal is generated by the DC-DC converter, the preset excitation signal is used to control the low-voltage battery to discharge to the high-voltage battery through the DC-DC converter, or to control the high-voltage battery to discharge to the low-voltage battery through the DC-DC converter. Therefore, the measurement of the impedance of the low-voltage battery is realized without the electrochemical workstation. Moreover, since the existing electrical components such as the low-voltage battery, DC-DC converter, and high-voltage battery are reused, the measurement cost of the impedance of the low-voltage battery is reduced.

[0033] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0035] Fig. 1 is a flow chart showing an impedance measurement method according to an exemplary embodiment.

[0036] FIG2 is a schematic diagram showing an excitation current signal according to an exemplary embodiment.

[0037] Fig. 3 is a flow chart showing an impedance measurement method according to an exemplary embodiment.

[0038] Fig. 4 is a flow chart showing an impedance measurement method according to an exemplary embodiment.

[0039] Fig. 5 is a schematic diagram showing connection relationships of a control system according to an exemplary embodiment.

[0040] Fig. 6 is a block diagram of an electric energy system according to an exemplary embodiment.

[0041] Fig. 7 is a block diagram showing a battery management system according to an exemplary embodiment.

[0042] Fig. 8 is a block diagram showing an electric energy device according to an exemplary embodiment.

[0043] FIG9 is a block diagram of a vehicle according to an exemplary embodiment. DETAILED DESCRIPTION

[0044] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0045] It should be understood that the various steps described in the method embodiments of the present disclosure may be performed in different orders and / or in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present disclosure is not limited in this respect.

[0046] As used herein, the term "including" and its variations are open-ended, i.e., "including but not limited to." The term "based on" means "based, at least in part, on." The term "one embodiment" means "at least one embodiment," the term "another embodiment" means "at least one additional embodiment," and the term "some embodiments" means "at least some embodiments." Other terms are defined in the following description.

[0047] It should be noted that the concepts of "first" and "second" mentioned in this disclosure are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0048] Before describing the embodiments of the present disclosure in detail, the electrical components involved in the embodiments of the present disclosure are first introduced.

[0049] In the embodiments of the present disclosure, the low-voltage battery may also be referred to as a starting battery, a low-voltage starting battery, etc., and may be used as a buffer memory for a vehicle power system (e.g., a 12V or 48V vehicle power system) of a motor vehicle. In some scenarios, the low-voltage battery may be designed with a voltage of 6 to 60V (typical values ​​12V or 48V). The low-voltage battery may include one or more battery cells.

[0050] In the embodiments of the present disclosure, the high-voltage battery, which may also be referred to as a power battery, traction battery, or energy storage battery, can be used to drive electric vehicles or hybrid vehicles. In some scenarios, the high-voltage battery can be designed with a voltage of 200 to 1000V (typical values ​​are 400V and 800V). The high-voltage battery may include multiple cells.

[0051] A DC-DC converter, also known as a DC-DC converter, is a circuit or electromechanical device that converts electrical energy into a DC power source (or near-DC) power source of a different voltage.

[0052] A battery management system (BMS), also known as a battery control system, is a system used to monitor and manage batteries. It can be located inside or outside the battery. A BMS can include both a high-voltage battery management system and a low-voltage battery management system.

[0053] It should be noted that the impedance measurement method of the disclosed embodiments can be applied not only to the impedance measurement of low-voltage batteries in vehicles, but also to the impedance measurement of low-voltage batteries in other devices. For example, other devices may include vehicles, ships, aircraft, energy storage cabinets, air conditioners, and other equipment that include low-voltage batteries, DC-DC converters, and high-voltage batteries. Unless otherwise specified, the vehicle is used as an example.

[0054] Among them, both the low-voltage battery and the high-voltage battery can be lithium-ion batteries, sodium-ion batteries or other types of batteries.

[0055] FIG1 is a flow chart of an impedance measurement method according to an exemplary embodiment. The method is applied to a control system connected to a low-voltage battery. The low-voltage battery includes at least one battery cell, and the low-voltage battery is connected to a high-voltage battery via a DC-DC converter. As shown in FIG1 , the impedance measurement method includes the following steps:

[0056] In step S101, the impedance information of at least one battery cell is determined based on the target current in the low-voltage battery and the target voltage of at least one battery cell; wherein the target current and the target voltage are the current and voltage of at least one battery cell under the action of a preset excitation signal, and the preset excitation signal is generated by a DC-DC converter, and the preset excitation signal is used to control the low-voltage battery to discharge to the high-voltage battery through the DC-DC converter, or to control the high-voltage battery to discharge to the low-voltage battery through the DC-DC converter.

[0057] In the embodiment of the present disclosure, a discharge excitation signal, i.e., a preset excitation signal, can be generated on the low-voltage battery side or the high-voltage battery side through a DC-DC converter. Under the action of the preset discharge excitation signal, the low-voltage battery can convert electrical energy to the high-voltage battery through the DC-DC converter, or the high-voltage battery can convert electrical energy to the low-voltage battery through the DC-DC converter.

[0058] In some embodiments, during the process of converting electrical energy from a low-voltage battery to a high-voltage battery through a DC-DC converter, or during the process of converting electrical energy from a high-voltage battery to a low-voltage battery through a DC-DC converter, that is, during the process of a preset excitation signal, a control system connected to the low-voltage battery can be used to collect the target current in the low-voltage battery. In addition, the voltage of each battery cell in the low-voltage battery, that is, the target voltage of at least one battery cell, can also be collected through the control system. The target current in the low-voltage battery can be the output current of the low-voltage battery or the output current of the at least one battery cell in the low-voltage battery.

[0059] In some embodiments, after obtaining the target current of the low-voltage battery and the target voltage of at least one battery cell, the impedance information of each battery cell can be determined based on the target current and the target voltage of the single battery cell. For example, if the low-voltage battery includes a single battery cell, the impedance information of the single battery cell can be determined; if the low-voltage battery includes multiple battery cells, the impedance information of each of the multiple battery cells can be determined.

[0060] In some embodiments, for a single battery cell, the impedance information of the battery cell can be calculated based on the target current and the target voltage of the single battery cell, where the impedance information can include a real part value and an imaginary part value.

[0061] In the embodiment of the present disclosure, the impedance measurement of the low-voltage battery may refer to measuring the impedance information of at least one battery cell included in the low-voltage battery, or it may refer to further obtaining the impedance information of the entire battery based on the impedance information of at least one battery cell after measuring the impedance information of at least one battery cell included in the low-voltage battery.

[0062] In some embodiments, the impedance information comprises electrochemical impedance spectroscopy.

[0063] By adopting the above method, the impedance information of at least one battery cell can be determined according to the target current in the low-voltage battery and the target voltage of at least one battery cell. Since the target current and the target voltage are the current and voltage of at least one battery cell under the action of a preset excitation signal, and the preset excitation signal is generated by a DC-DC converter, the preset excitation signal is used to control the low-voltage battery to discharge to the high-voltage battery through the DC-DC converter, or to control the high-voltage battery to discharge to the low-voltage battery through the DC-DC converter. Therefore, the measurement of the impedance of the low-voltage battery is realized without the electrochemical workstation. Moreover, since the existing electrical components such as the low-voltage battery, DC-DC converter, and high-voltage battery are reused, the measurement cost of the impedance of the low-voltage battery is reduced.

[0064] In some embodiments, the control system is connected to a DC-DC converter. In this case, the method of the embodiment of the present disclosure may further include the following steps:

[0065] A first request is sent to the DC-DC converter, where the first request is used to control the DC-DC converter to generate a preset excitation signal.

[0066] In an embodiment of the present disclosure, the control system is connected to a DC-DC converter. In this way, when the control system determines that the impedance measurement of the low-voltage battery needs to be performed, the control system can send a first request to the DC-DC converter to enable the DC-DC converter to generate a preset excitation signal.

[0067] In some embodiments, the control system may determine that the impedance measurement of the low-voltage battery needs to be performed upon receiving a measurement instruction from a user.

[0068] In some implementations, sending the first request to the DC-DC converter may include the following steps:

[0069] In response to determining that the preset condition is satisfied, a first request is sent to the DC-DC converter.

[0070] In an embodiment of the present disclosure, when the control system determines that the impedance measurement of the low-voltage battery is required, it can further determine whether the measurement conditions are met, that is, determine whether the preset conditions are met. When the control system determines that the preset conditions are met, it can send a first request to the DC-DC converter in response to determining that the preset conditions are met.

[0071] In some embodiments, the preset condition includes at least one of whether the low-voltage battery load is stable, whether the SOC (state of charge) of the high-voltage battery is lower than a limit SOC, and whether a low-voltage battery safe operation limit condition is met.

[0072] When the low-voltage battery load is stable, for example, when the vehicle is in a parked state or a constant-current charging state, it is determined that the preset condition is met.

[0073] Among them, when the SOC of the high-voltage battery is lower than the limit SOC, it is determined that the preset conditions are met. In this way, it can be ensured that during the measurement of the cell impedance of the low-voltage battery, the energy charged into the high-voltage battery through the DC-DC converter will not cause overcharging of the high-voltage battery.

[0074] In some implementations, in order to obtain more comprehensive impedance information, the method of the embodiment of the present disclosure may further include the following steps:

[0075] Determine the frequency point to be measured corresponding to the low-voltage battery; for any one or more frequency points to be measured, generate a corresponding first request based on the one or more frequency points to be measured, and the first request is used to control the DC-DC converter to generate a preset excitation signal corresponding to the one or more frequency points to be measured.

[0076] In this case, determining the impedance information of at least one battery cell according to the target current in the low-voltage battery and the target voltage of at least one battery cell may include the following steps:

[0077] Impedance information of at least one battery cell is determined according to target currents corresponding to all frequency points to be measured and target voltages of at least one battery cell.

[0078] In the disclosed embodiment, the control system can determine the required frequency range for measurement based on the characteristics of the cells in the low-voltage battery and set specific frequency points within the frequency range according to the requirements of a preset algorithm, i.e., the frequency points to be measured corresponding to the low-voltage battery. After determining the frequency points to be measured, a corresponding first request can be generated based on any one or more of the frequency points to be measured, so that the DC-DC converter generates a preset excitation signal corresponding to the one or more frequency points to be measured based on the first request.

[0079] After each target current and target voltage corresponding to a preset excitation signal are collected, a new first request may be generated based on one or more of the remaining frequency points to be measured, and the preset excitation signal generation and the collection of the target current and target voltage may be repeated.

[0080] Subsequently, after generating the first request corresponding to all frequency points, the control system can collect the target current corresponding to all frequency points to be measured and the target voltage of at least one battery cell. Thus, the control system can further determine the impedance information of at least one battery cell based on the target current corresponding to all frequency points to be measured and the target voltage of at least one battery cell.

[0081] Among them, when a corresponding first request is generated according to multiple frequency points to be measured, the subsequent DC-DC converter can generate an excitation signal with multiple frequency points superimposed according to the first request, so that impedance information corresponding to multiple different frequency points can be obtained during one measurement process, thereby improving the measurement speed.

[0082] In some embodiments, the preset excitation signal is a current signal, the current signal includes an alternating current component, and the alternating current component is an alternating current signal with multiple frequencies superimposed.

[0083] In the embodiment of the present disclosure, by superimposing multiple frequency points in the AC current signal, impedance information corresponding to multiple different frequency points can be obtained during one measurement process, thereby improving the measurement speed.

[0084] In some implementations, in order to avoid signal measurement errors and improve signal measurement accuracy, the AC current signal may be superimposed with 1 to 5 frequency points.

[0085] In some embodiments, the excitation current signal may include two parts: an excitation DC current component Idc and an excitation AC current component Iac. The excitation AC current component Iac may be a sinusoidal current signal with N frequencies superimposed. The excitation AC current component Iac may be specifically expressed as follows: Iac = Iamp*[sin(ω1*t)+sin(ω2*t)+…+sin(ω_N*t)]

[0086] Wherein, ω_N represents the Nth frequency point, N is a positive integer, generally ranging from 1 to 5, and Iamp represents the amplitude of the excitation current.

[0087] As shown in FIG2 , a schematic diagram of an excitation current signal when N=1 is shown.

[0088] In some embodiments, the sweep frequency range of the excitation current may include 0.01 Hz to 1000 Hz; the amplitude Iamp of the excitation current may be any value between 0.1 A and 5 A; and the DC bias Idc of the excitation current is ≥ the peak value of Iac to ensure that the DC-DC converter is in a unidirectional operating mode.

[0089] In some embodiments, to obtain more comprehensive impedance information, in the embodiment of the present disclosure, determining the impedance information of at least one battery cell according to the target current in the low-voltage battery and the target voltage of at least one battery cell may include the following steps:

[0090] Impedance information of at least one battery cell is determined according to target currents corresponding to the multiple acquisition moments in the low-voltage battery and target voltages corresponding to the at least one battery cell at the multiple acquisition moments.

[0091] In the embodiment of the present disclosure, corresponding to a preset excitation signal, the control system can collect the target current in the low-voltage battery and the target voltage of at least one battery cell at multiple different collection moments under the action of the preset excitation signal, thereby obtaining the target current in the low-voltage battery at the multiple collection moments and the target voltage of at least one battery cell at the multiple collection moments. Then, the control system can determine the impedance information of at least one battery cell based on the target current in the low-voltage battery at the multiple collection moments and the target voltage of at least one battery cell at the multiple collection moments.

[0092] For example, for the excitation signal Curr(i), at different acquisition times, the control system can acquire (n+1) sets of synchronous sampling data under the excitation of Curr(i), which are respectively expressed as:

[0093] {V1[t0],V1[t1],...,V1[tx]};

[0094] {V2[t0],V2[t1],...,V2[tx]};

[0095] …;

[0096] {Vn[t0],Vn[t1],...,Vn[t]};

[0097] {I[t0],I[t1],...,I[tx]};

[0098] Where Vn[tx] is the target voltage value of the nth cell sampled at time tx, and I[tx] is the current value synchronously sampled at time tx.

[0099] In some embodiments, considering that the number of cells in the low-voltage battery is small, the control system may use the same voltage sampling chip to sample the target voltages of the cells in the low-voltage battery to save data acquisition costs.

[0100] FIG3 is a flow chart of an impedance measurement method according to an exemplary embodiment. The method is applied to an electric energy device, wherein the electric energy device may be, for example, a vehicle, a ship, an aircraft, an energy storage cabinet, an air conditioner, etc. The electric energy device includes a low-voltage battery, a high-voltage battery, a DC-DC converter, and a control system connected to the low-voltage battery. The low-voltage battery includes at least one battery cell, and the low-voltage battery is connected to the high-voltage battery via the DC-DC converter. As shown in FIG3 , the impedance measurement method includes the following steps:

[0101] In step S301, a preset excitation signal is generated by a DC-DC converter, and the preset excitation signal is used to control the low-voltage battery to discharge to the high-voltage battery through the DC-DC converter, or to control the high-voltage battery to discharge to the low-voltage battery through the DC-DC converter.

[0102] In step S302, the control system determines the impedance information of at least one battery cell based on the target current in the low-voltage battery and the target voltage of at least one battery cell; wherein the target current and target voltage are the current and voltage of at least one battery cell under the action of a preset excitation signal.

[0103] The detailed description of steps S301 - S302 can be referred to the aforementioned embodiment and will not be repeated here.

[0104] By adopting the above method, a preset excitation signal is generated by a DC-DC converter. The preset excitation signal is used to control the low-voltage battery to discharge to the high-voltage battery through the DC-DC converter, or to control the high-voltage battery to discharge to the low-voltage battery through the DC-DC converter. The control system can determine the impedance information of at least one battery cell according to the target current in the low-voltage battery and the target voltage of at least one battery cell, thereby realizing the impedance measurement of the low-voltage battery separated from the electrochemical workstation. Moreover, since the existing electrical components such as the low-voltage battery, DC-DC converter, and high-voltage battery are reused, the measurement cost of the low-voltage battery impedance is reduced.

[0105] The impedance measurement method of the present disclosure is described below with reference to a complete embodiment in conjunction with FIG4 . As shown in FIG4 , the impedance measurement method includes:

[0106] S401, the control system determines whether a preset condition is met, and if so, executes step S402.

[0107] S402: For any one or more frequency points to be measured, the control system generates a corresponding first request according to the one or more frequency points to be measured.

[0108] S403: The control system sends a first request to the DC-DC converter.

[0109] S404: The DC-DC converter generates a preset excitation signal according to the first request.

[0110] The preset excitation signal is used to control the low-voltage battery to discharge to the high-voltage battery through the DC-DC converter, or to control the high-voltage battery to discharge to the low-voltage battery through the DC-DC converter.

[0111] S405 , the control system collects target currents corresponding to multiple collection moments in the low-voltage battery and target voltages corresponding to multiple collection moments of at least one battery cell.

[0112] The target current and target voltage are the current and voltage under the action of the preset excitation signal.

[0113] S406, the control system determines whether the target currents at all the frequencies to be measured and the target voltage of at least one battery cell are completed, if so, step S407 is executed, if not, the control system returns to step S402.

[0114] S407, the control system determines impedance information of at least one battery cell according to the target currents corresponding to the low-voltage batteries at all the frequencies to be measured at multiple acquisition times and the target voltages corresponding to the at least one battery cell at multiple acquisition times.

[0115] The detailed description of steps S401-S407 can be referred to the aforementioned embodiment and will not be repeated here.

[0116] In another exemplary embodiment, as shown in Figure 5, a control system 510 is also provided. The control system 510 is used to cooperate with the low-voltage battery 520, the high-voltage battery 530 and the DC-DC converter 540. The low-voltage battery 520 includes at least one battery cell, and the low-voltage battery 520 is connected to the high-voltage battery 530 through the DC-DC converter 540. The control system 510 is used to implement the steps of the above-mentioned low-voltage impedance measurement method.

[0117] In some embodiments, the control system 510 may be one or more chips, controllers, integrated circuits, or computer terminals.

[0118] In another exemplary embodiment, as shown in Figure 6, an electric energy system 600 is also provided, including a low-voltage battery 520, a high-voltage battery 530, a DC-DC converter 540 and a control system 510. The low-voltage battery 520 includes at least one battery cell, and the low-voltage battery 520 is connected to the high-voltage battery 530 through the DC-DC converter 540.

[0119] In another exemplary embodiment, a non-transitory computer-readable storage medium including a computer program is further provided. When the computer program is executed by a processor, the steps of the above impedance measurement method are implemented.

[0120] In another exemplary embodiment, as shown in FIG7 , a battery management system 700 is further provided, including:

[0121] Non-volatile memory 710, for storing computer programs executable by the processor;

[0122] The processor 720 is configured to execute a computer program to implement the steps of the above-mentioned impedance measurement method.

[0123] In another exemplary embodiment, as shown in FIG8 , an electric energy device 800 is provided, including the above-mentioned battery management system 700 .

[0124] Fig. 9 is a block diagram of a vehicle 900 according to an exemplary embodiment. The vehicle 900 may be an autonomous vehicle, a semi-autonomous vehicle, or a non-autonomous vehicle.

[0125] 9 , vehicle 900 may include various subsystems, such as an infotainment system 910, a perception system 920, a decision-making and control system 930, a drive system 940, and an onboard computing platform 950. Vehicle 900 may also include more or fewer subsystems, and each subsystem may include multiple components. Furthermore, each subsystem and each component of vehicle 900 may be interconnected via wired or wireless means.

[0126] In some embodiments, the infotainment system 910 may include a communication system, an entertainment system, a navigation system, and the like.

[0127] The perception system 920 may include several sensors for sensing information about the environment surrounding the vehicle 900. For example, the perception system 920 may include a global positioning system (which may be a GPS system, a BeiDou system, or another positioning system), an inertial measurement unit (IMU), a laser radar, a millimeter-wave radar, an ultrasonic radar, and a camera.

[0128] The decision control system 930 may include a computing system, a domain controller, a vehicle controller, an energy dispatcher, a steering system, a high-voltage battery management system, a low-voltage battery management system, a throttle and a braking system, wherein the low-voltage battery management system is used to perform all or part of the steps of the above-mentioned impedance measurement method.

[0129] The drive system 940 may include components that provide power to the vehicle 900. In one embodiment, the drive system 940 may include an engine, a power source, a transmission system, and wheels. The engine may be an internal combustion engine, an electric motor, an air compression engine, or a combination thereof. The engine is capable of converting energy provided by the power source into mechanical energy.

[0130] Some or all functions of the vehicle 900 are controlled by an onboard computing platform 950. The onboard computing platform 950 may include at least one processor 951 and a memory 952. The processor 951 may execute instructions 953 stored in the memory 952.

[0131] The processor 951 can be any conventional processor, such as a commercially available CPU. The processor can also include a graphics processor (GPU), a field programmable gate array (FPGA), a system on chip (SOC), an application specific integrated circuit (ASIC), or a combination thereof.

[0132] The memory 952 can be implemented by any type of volatile or non-volatile memory device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0133] In addition to instructions 953 , memory 952 may also store data, such as road maps, route information, and vehicle location, direction, speed, etc. The data stored in memory 952 may be used by the onboard computing platform 950 .

[0134] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.

[0135] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0136] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. An impedance measurement method, characterized in that: A control system is applied to a control system connected to a low-voltage battery, the low-voltage battery including at least one battery cell, and the low-voltage battery is connected to a high-voltage battery via a DC-DC converter, the method comprising: The impedance information of the at least one battery cell is determined based on the target current in the low-voltage battery and the target voltage of the at least one battery cell; wherein the target current and the target voltage are the current and voltage of the at least one battery cell under the action of a preset excitation signal, and the preset excitation signal is generated by the DC-DC converter, and the preset excitation signal is used to control the low-voltage battery to discharge to the high-voltage battery through the DC-DC converter, or to control the high-voltage battery to discharge to the low-voltage battery through the DC-DC converter (S101).

2. The method according to claim 1, characterized in that The method further comprises: Determine the frequency point to be measured corresponding to the low-voltage battery; For any one or more of the frequency points to be measured, generating a corresponding first request according to the one or more frequency points to be measured, wherein the first request is used to control the DC-DC converter to generate the preset excitation signal corresponding to the one or more frequency points to be measured; The determining the impedance information of the at least one battery cell according to the target current in the low-voltage battery and the target voltage of the at least one battery cell includes: The impedance information of the at least one battery cell is determined according to the target current corresponding to all the frequency points to be measured and the target voltage of the at least one battery cell.

3. The method according to claim 1 or 2, characterized in that The preset excitation signal is a current signal, the current signal includes an alternating current component, and the alternating current component is an alternating current signal with multiple frequency points superimposed.

4. The method according to any one of claims 1 to 3, characterized in that The determining the impedance information of the at least one battery cell according to the target current in the low-voltage battery and the target voltage of the at least one battery cell includes: The impedance information of the at least one battery cell is determined according to the target current of the low-voltage battery at the multiple acquisition moments and the target voltage of the at least one battery cell at the multiple acquisition moments.

5. The method according to any one of claims 1 to 4, characterized in that The impedance information includes electrochemical impedance spectroscopy.

6. The method according to any one of claims 1 to 5, characterized in that The control system is connected to the DC-DC converter, and the method further includes: A first request is sent to the DC-DC converter, where the first request is used to control the DC-DC converter to generate the preset excitation signal.

7. The method according to claim 6, characterized in that The sending a first request to the DC-DC converter includes: In response to determining that a preset condition is satisfied, the first request is sent to the DC-DC converter.

8. A control system, the control system is used to cooperate with a low-voltage battery, a high-voltage battery and a DC-DC converter, the low-voltage battery includes at least one battery cell, and the low-voltage battery is connected to the high-voltage battery through a DC-DC converter, characterized in that: The control system is used to implement the steps of the impedance measurement method according to any one of claims 1 to 7.

9. An electric energy system, characterized in that: It includes a low-voltage battery, a high-voltage battery, a DC-DC converter and a control system. The low-voltage battery includes at least one battery cell, and the low-voltage battery is connected to the high-voltage battery through a DC-DC converter. The control system is the control system described in claim 8.

10. An impedance measurement method, characterized in that: Applied to electric energy equipment, the electric energy equipment includes a low-voltage battery, a high-voltage battery, a DC-DC converter, and a control system connected to the low-voltage battery, the low-voltage battery includes at least one battery cell, and the low-voltage battery is connected to the high-voltage battery via the DC-DC converter, the method includes: generating a preset excitation signal through the DC-DC converter, wherein the preset excitation signal is used to control the low-voltage battery to discharge to the high-voltage battery through the DC-DC converter, or to control the high-voltage battery to discharge to the low-voltage battery through the DC-DC converter (S301); The control system determines the impedance information of the at least one battery cell based on the target current in the low-voltage battery and the target voltage of the at least one battery cell; wherein the target current and the target voltage are the current and voltage of the at least one battery cell under the action of a preset excitation signal (S302).

11. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the impedance measurement method according to any one of claims 1 to 7 are implemented.

12. A battery management system, characterized in that: include: a non-volatile memory for storing computer programs executable by the processor; A processor, configured to execute a computer program to implement the steps of the impedance measurement method according to any one of claims 1 to 7.

13. An electric energy device, characterized in that: Including the battery management system according to claim 12.

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