Safety verification method, device and equipment for dual-current sampling of energy storage system and medium

Abstract

The invention provides a safety verification method, device and equipment for dual-current sampling of an energy storage system and a medium. The safety verification method comprises the steps that a first current detection part is arranged at the positive electrode end of a battery in a battery heating loop and located outside the heating loop, and a second current detection part is arranged at the negative electrode end of the battery; based on a first current sampling signal, collected in real time, of the first current detection component and a second current sampling signal, collected in real time, of the second current detection component, heating loop current is determined, and battery heating loop state monitoring and fault diagnosis are carried out based on the heating loop current; and performing frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis on the first current sampling signal and the second current sampling signal to determine the abnormality of the current detection component and dynamically select a main loop current value. Mutual verification of double current sampling is realized, system reliability and function safety are improved, and the number of hardware current sampling is not increased.

Description

Technical Field

[0001] This application relates to the technical field of energy storage systems, and in particular to a method, apparatus, equipment and medium for safety verification of dual current sampling in energy storage systems. Background Technology

[0002] Current mainstream energy storage systems generally adopt a single current sampling architecture: a single current sensor (such as a current sensing resistor, Hall sensor, or fluxgate sensor) is set in the main battery circuit to collect the current value at this point to achieve core functions such as SOC estimation, charge / discharge control, and overcurrent / short-circuit protection. This architecture has inherent defects: once the current sensor's sampling accuracy is inaccurate due to temperature drift, aging, core saturation, or PCB trace interference, it will directly cause accumulated SOC deviation, capacity statistical distortion, and malfunction of current-related software protection functions (such as unwarranted charge limiting) or failure to operate (such as failure to cut off overcurrent), seriously threatening system safety. To improve the reliability of thermal management, some energy storage systems in high-altitude and cold regions add independent heating circuits, which are usually composed of heating films, heating circuit switching devices (such as MOSFETs), and dedicated current sampling units. Traditional solutions require an additional current sensor for heating circuit current monitoring to diagnose faults such as heating open circuits and abnormal resistance values. However, this design presents three contradictions: (1) Increased hardware costs: Each BMS requires an additional high-precision current sensor and supporting signal conditioning circuit; (2) Limited fault diagnosis dimensions: Existing heating fault criteria mostly rely on steady-state current amplitude or simple threshold comparison, making it difficult to identify local detachment of the heating film. Therefore, a new current sampling safety verification scheme that balances hardware economy and real-time verification is urgently needed. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a safety verification method, device, equipment and medium for dual current sampling of energy storage systems, which performs fault detection of battery heating circuit based on heating circuit current, and performs frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis to achieve mutual verification of dual current sampling, improve system reliability and functional safety, and does not increase the number of hardware current samples.

[0004] This application provides a safety verification method for dual current sampling in an energy storage system, the safety verification method comprising: A first current detection component is installed at the positive terminal of the battery in the battery heating circuit and at a position outside the heating circuit, and a second current detection component is installed at the negative terminal of the battery. Based on the first current sampling signal of the first current detection component and the second current sampling signal of the second current detection component collected in real time, the heating circuit current is determined, and the battery heating circuit status is monitored and fault diagnosis is performed based on the heating circuit current. The first current sampling signal and the second current sampling signal are subjected to frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis to determine the abnormality of the current detection component and dynamically select the main circuit current value.

[0005] In one possible implementation, determining the heating circuit current based on the first current sampling signal from the first current detection component and the second current sampling signal from the second current detection component acquired in real time, and performing battery heating circuit status monitoring and fault diagnosis based on the heating circuit current, includes: The heating circuit current is determined based on the first current sampling signal and the second current sampling signal; When there is voltage between the positive and negative terminals of the battery and the heating MOSFET is in the closed state, if the current of the heating circuit is within the fault preset range, then the open circuit fault of the heating circuit is determined. When there is a voltage between the positive and negative terminals of the battery and the heating MOSFET is in the closed state, if the deviation between the resistance value of the heating resistor calculated based on Ohm's law and the rated resistance value exceeds the threshold, then the heating resistance value of the battery heating circuit is determined to be abnormal. When there is a voltage between the positive and negative terminals of the battery, the heating MOSFET is in a closed state, and the current of the heating circuit is within the preset normal range, if the measured temperature rise rate is lower than the expected threshold, it is determined that the heating film has detached. If the heating MOSFET receives a disconnect command or is in a disconnected state, and the heating circuit current remains greater than zero, then the heating MOSFET is determined to be stuck together.

[0006] In one possible implementation, the step of performing frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis on the first current sampling signal and the second current sampling signal to determine the anomaly of the current detection component and dynamically select the main circuit current value includes: Frequency component analysis and DC component extraction are performed on the first current sampling signal and the second current sampling signal to determine the first fundamental frequency and the first DC current of the first current sampling signal, and the second fundamental frequency and the second DC current of the second current sampling signal. Based on the first fundamental frequency and the second fundamental frequency, the consistency of frequency domain harmonic energy distribution is judged to determine the abnormality of the current detection component; Based on the first DC current and the second DC current, a time-domain steady-state current deviation analysis is performed to dynamically select the main circuit current value.

[0007] In one possible implementation, the step of performing time-domain steady-state current deviation analysis based on the first DC current and the second DC current to dynamically select the main circuit current value includes: When any current sensing component is found to be malfunctioning, the system checks whether the heating MOSFET is in an off state. If so, the estimated current that should flow through the main circuit is determined based on the battery's current state of charge, temperature, and terminal voltage and internal resistance characteristics in a static state. Based on the first DC current, the second DC current, and the estimated current, a time-domain steady-state current deviation analysis is performed, and the main circuit current value is selected according to the directionality and relative amplitude relationship of the deviation.

[0008] In one possible implementation, the step of performing time-domain steady-state current deviation analysis based on the first DC current, the second DC current, and the estimated current, and selecting the main circuit current value according to the directionality and relative amplitude of the deviation, includes: The first DC current and the second DC current are compared with the estimated current, respectively. If both the first DC current and the second DC current are close to the estimated current, or if the first DC current and the second DC current deviate from the estimated current in the same direction and the degree of deviation is within a preset deviation range, then the average value of the first DC current and the second DC current will be used as the main circuit current value. If the above conditions are not met, then the DC current that is closer to the estimated current between the first DC current and the second DC current shall be selected as the main circuit current value.

[0009] In one possible implementation, the battery heating circuit includes a battery, a charging MOSFET, a discharging MOSFET, a heating MOSFET, an energy management system, and a heating resistor; wherein, The negative terminal of the battery is electrically connected to the drain of the charging MOSFET, the source of the charging MOSFET is electrically connected to the drain of the discharging MOSFET, the source of the discharging MOSFET is electrically connected to the first terminal of the heating resistor, the second terminal of the heating resistor is electrically connected to the drain of the heating MOSFET, and the source of the heating MOSFET is electrically connected to the positive terminal of the battery. Furthermore, the gates of the charging MOSFET, the discharging MOSFET, and the heating MOSFET are all electrically connected to the energy management system.

[0010] This application embodiment also provides a safety verification device for dual current sampling of an energy storage system, the safety verification device comprising: The module is configured to install a first current detection component at the positive terminal of the battery in the battery heating circuit and at a position outside the heating circuit, and to install a second current detection component at the negative terminal of the battery. The dual-current first detection module is used to determine the heating circuit current based on the first current sampling signal of the first current detection component and the second current sampling signal of the second current detection component acquired in real time, and to perform battery heating circuit status monitoring and fault diagnosis based on the heating circuit current. The dual-current second detection module is used to perform frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis on the first current sampling signal and the second current sampling signal, to determine the abnormality of the current detection component and dynamically select the main circuit current value.

[0011] This application embodiment also provides an electronic device, including: a processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor communicates with the memory via the bus. When the machine-readable instructions are executed by the processor, the steps of the security verification method for dual current sampling of energy storage systems described above are performed.

[0012] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the steps of the above-described security verification method for dual current sampling in an energy storage system.

[0013] This application provides a safety verification method, apparatus, device, and medium for dual current sampling in an energy storage system. The safety verification method includes: setting a first current detection component at the positive terminal of the battery in a battery heating circuit, located outside the heating circuit, and setting a second current detection component at the negative terminal of the battery; determining the heating circuit current based on the real-time acquired first current sampling signal from the first current detection component and the second current sampling signal from the second current detection component, and performing battery heating circuit status monitoring and fault diagnosis based on the heating circuit current; performing frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis on the first current sampling signal and the second current sampling signal to determine the anomaly of the current detection component and dynamically select the main circuit current value. By performing battery heating circuit fault detection based on the heating circuit current, and simultaneously performing frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis, dual current sampling mutual verification is achieved, improving system reliability and functional safety without increasing the number of hardware current samples.

[0014] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A flowchart illustrating a safety verification method for dual current sampling in an energy storage system, provided in this application embodiment; Figure 2 This is a schematic diagram of a battery heating circuit provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of a dual current sampling device for an energy storage system provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. Based on the embodiments of this application, every other embodiment obtained by those skilled in the art without inventive effort falls within the scope of protection of this application.

[0018] First, the applicable application scenarios of this application will be introduced. This application can be applied to the technical field of energy storage systems.

[0019] Research has revealed that current mainstream energy storage systems generally employ a single current sampling architecture: a single current sensor (such as a current sensing resistor, Hall effect sensor, or fluxgate sensor) is placed in the battery's main circuit to collect the current value at that point, enabling core functions such as SOC estimation, charge / discharge control, and overcurrent / short-circuit protection. This architecture has inherent flaws: if the current sensor's sampling accuracy becomes inaccurate due to temperature drift, aging, core saturation, or PCB trace interference, it will directly lead to accumulated SOC deviation, capacity statistical distortion, and cause malfunctions (such as unwarranted charge limiting) or failure to activate current-related software protection functions (such as failure to cut off overcurrent), seriously threatening system safety. To improve thermal management reliability, some energy storage systems in high-altitude and cold regions add independent heating circuits, typically consisting of a heating film, heating circuit switching devices (such as MOSFETs), and a dedicated current sampling unit. Traditional solutions require an additional current sensor for heating circuit current monitoring to diagnose faults such as open circuits and abnormal resistance. However, this design presents three contradictions: (1) Increased hardware costs: Each BMS requires an additional high-precision current sensor and supporting signal conditioning circuit; (2) Limited fault diagnosis dimensions: Existing heating fault criteria mostly rely on steady-state current amplitude or simple threshold comparison, making it difficult to identify local detachment of the heating film. Therefore, a new current sampling safety verification scheme that balances hardware economy and real-time verification is urgently needed.

[0020] Based on this, the present application provides a safety verification method for dual current sampling of an energy storage system. The method performs fault detection of the battery heating circuit based on the heating circuit current, and simultaneously performs frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis. This achieves mutual verification of dual current sampling, improves system reliability and functional safety, and does not increase the number of hardware current samples.

[0021] Please see Figure 1 , Figure 1 This is a flowchart illustrating a safety verification method for dual current sampling in an energy storage system, provided as an embodiment of this application. Figure 1 As shown in the embodiments of this application, the security verification method includes: S101: A first current detection component is provided at the positive terminal of the battery in the battery heating circuit and at a position outside the heating circuit, and a second current detection component is provided at the negative terminal of the battery.

[0022] In this step, a first current detection component is installed at the positive terminal of the battery in the battery heating circuit and at a position outside the heating circuit, and a second current detection component is installed at the negative terminal of the battery.

[0023] Here, a first current detection component (denoted as sampling point I1) is installed at the positive terminal of the energy storage system battery pack (outside the heating circuit), and a second current detection component (denoted as sampling point I2) is installed at the negative terminal of the battery pack (inside the main circuit switch). Both detection components use high-precision current sensing resistors, with the calibration accuracy of channel I1 being ±1% and channel I2 being ±0.1%. The two are sampled synchronously with a time deviation ≤100ns.

[0024] For further details, please refer to Figure 2 , Figure 2 This is a schematic diagram of a battery heating circuit provided in an embodiment of this application. Figure 2 As shown, the battery heating circuit includes a battery, a charging MOSFET, a discharging MOSFET, a heating MOSFET, an energy management system, and a heating resistor; wherein, the negative terminal of the battery is electrically connected to the drain of the charging MOSFET, the source of the charging MOSFET is electrically connected to the drain of the discharging MOSFET, the source of the discharging MOSFET is electrically connected to the first terminal of the heating resistor, the second terminal of the heating resistor is electrically connected to the drain of the heating MOSFET, and the source of the heating MOSFET is electrically connected to the positive terminal of the battery; and the gates of the charging MOSFET, the discharging MOSFET, and the heating MOSFET are all electrically connected to the energy management system.

[0025] It should be noted that the first current detection component is located in Figure 2 At position I1, the second current detection component is located Figure 2 At position I2.

[0026] S102: Based on the first current sampling signal of the first current detection component and the second current sampling signal of the second current detection component collected in real time, the heating circuit current is determined, and the battery heating circuit status is monitored and fault diagnosis is performed based on the heating circuit current.

[0027] In this step, the heating circuit current is determined based on the first current sampling signal of the first current detection component and the second current sampling signal of the second current detection component, and the battery heating circuit status is monitored and fault diagnosis is performed based on the heating circuit current.

[0028] In one possible implementation, determining the heating circuit current based on the first current sampling signal from the first current detection component and the second current sampling signal from the second current detection component acquired in real time, and performing battery heating circuit status monitoring and fault diagnosis based on the heating circuit current, includes: (1): The heating circuit current is determined based on the first current sampling signal and the second current sampling signal.

[0029] Here, the positive direction of current is defined as follows: charging current is positive, discharging current is negative, and heating current is always positive (flowing from the positive terminal of the battery through the heating film to the negative terminal). Let the on-state signal of the heating MOSFET be H_state (H_state=1 indicates closed, H_state=0 indicates open), then the heating circuit current... Calculate in real time according to the following logic: When the heating MOSFET is closed, I1 is the first current sampling signal, and I2 is the second current sampling signal. The difference between the two is the current flowing through the heating circuit. When H_state=0, I1=I2, therefore... =0.

[0030] (2): When there is a voltage between the positive and negative terminals of the battery and the heating MOS transistor is in a closed state, if the current of the heating circuit is within the fault preset range, then the open circuit fault of the heating circuit is determined.

[0031] Here, when there is voltage between the positive and negative terminals of the battery and the heating MOSFET is in a closed state, if the current of the heating circuit is within the fault preset range (±1A), then the open circuit fault of the heating circuit is determined.

[0032] (3): When there is a voltage between the positive and negative terminals of the battery and the heating MOS transistor is in the closed state, if the deviation between the resistance value of the heating resistor calculated based on Ohm's law and the rated resistance value exceeds the threshold, then the abnormal heating resistance value fault of the battery heating circuit is determined.

[0033] Here, when there is a voltage between the positive and negative terminals of the battery and the heating MOSFET is in the closed state, if the deviation between the resistance value of the heating resistor calculated based on Ohm's law and the rated resistance value exceeds the threshold (10%), then an abnormal heating resistance fault in the battery heating circuit is determined.

[0034] It should be noted that the rated resistance value is determined based on the rated power and nominal voltage.

[0035] (4): When there is a voltage between the positive and negative terminals of the battery, the heating MOS transistor is in a closed state, and the current of the heating circuit is within the preset normal range, if the measured temperature rise rate is lower than the expected threshold, it is determined that the heating film has fallen off.

[0036] It should be noted that the expected threshold is determined by looking up the current SOC and the corresponding temperature table.

[0037] (5): When the heating MOS transistor receives a disconnect command or is in a disconnected state, if the current in the heating circuit is still greater than zero, then the heating MOS transistor is determined to be stuck.

[0038] Here, the drive command has turned off the heating MOS, but actual testing... If the problem persists, it indicates that the heating MOSFET has broken down or the drive circuit has failed.

[0039] The fault diagnosis results mentioned above directly affect the system safety strategy as follows: open circuit / adhesion faults trigger a level 2 fault, immediately disconnecting the main circuit relay and reporting to the CAN bus; abnormal resistance / detachment faults trigger a level 1 fault, limiting power operation and initiating active cooling; all fault states are frozen. The weighting coefficients used for SOC correction prevent metering errors introduced by heating current from contaminating the state of charge estimation.

[0040] S103: Perform frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis on the first current sampling signal and the second current sampling signal to determine the abnormality of the current detection component and dynamically select the main circuit current value.

[0041] In this step, a hierarchical dual-mode verification is performed on the first current sampling signal (at the positive terminal) and the second current sampling signal (inside the negative terminal switch): first, the consistency of frequency domain harmonic energy distribution is used to determine whether the hardware sampling link has experienced a systematic failure; then, on the premise that the frequency domain verification is passed, based on the deviation relationship between the time domain steady-state DC component and the model-estimated current, the current value with higher reliability is dynamically selected as the main circuit current reference.

[0042] In one possible implementation, the step of performing frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis on the first current sampling signal and the second current sampling signal to determine the anomaly of the current detection component and dynamically select the main circuit current value includes: A: Perform frequency component analysis and DC component extraction on the first current sampling signal and the second current sampling signal to determine the first fundamental frequency and the first DC current of the first current sampling signal, and the second fundamental frequency and the second DC current of the second current sampling signal.

[0043] Here, the AC components are extracted from I1 and I2 respectively:

[0044] in, for i The DC component of the current.

[0045] Then pure AC component for:

[0046] Perform Fast Fourier Transform (FFT) on the AC components of I1 and I2 respectively to obtain the frequency spectra:

[0047] in, For the first i The complex spectrum value of the k-th frequency component obtained by performing an FFT on the AC component of a current.

[0048] Peak values ​​at each frequency were obtained. :

[0049] Where N is the number of sampling points. Calculate the effective values ​​of each harmonic:

[0050] Calculate the total harmonic distortion (THD):

[0051] in, It is the effective value of the kth harmonic of the i-th current.

[0052] B: Based on the first fundamental frequency and the second fundamental frequency, the consistency of frequency domain harmonic energy distribution is judged to determine the abnormality of the current detection component.

[0053] Here, the consistency of frequency domain harmonic energy distribution is judged based on the first fundamental frequency and the second fundamental frequency to determine the abnormality of the current detection component.

[0054] In one possible implementation, the step of determining the consistency of frequency domain harmonic energy distribution based on the first fundamental frequency and the second fundamental frequency to identify the anomaly of the current detection component includes: a: Determine the energy proportions of the first fundamental frequency and the second fundamental frequency in the overall fluctuation component.

[0055] It should be noted that the energy proportion of the first fundamental frequency in the overall fluctuation component refers to the normalized proportion of the harmonic component energy in a specific frequency range (such as 50Hz±2Hz or 100Hz±2Hz) of the pure AC component obtained after the DC component is eliminated from the first current sampling signal, in the total AC energy of its full frequency band (0Hz to Nyquist frequency).

[0056] b: Compare the component energy ratio of the first fundamental frequency with the component energy ratio of the second fundamental frequency. When the component energy ratio of either component is lower than the component energy ratio of the other, and the difference reaches or exceeds a preset ratio threshold, it is determined that the current detection component corresponding to the lower component energy ratio is malfunctioning.

[0057] Here, the component energy ratio of the first fundamental frequency is compared with the component energy ratio of the second fundamental frequency. When the component energy ratio of either component is lower than the component energy ratio of the other, and the difference reaches or exceeds the preset ratio threshold, it is determined that the current detection component corresponding to the lower component energy ratio is malfunctioning.

[0058] C: Based on the first DC current and the second DC current, perform time-domain steady-state current deviation analysis to dynamically select the main circuit current value.

[0059] Here, a time-domain steady-state current deviation analysis is performed based on the first DC current and the second DC current to dynamically select the main circuit current value.

[0060] In one possible implementation, the step of performing time-domain steady-state current deviation analysis based on the first DC current and the second DC current to dynamically select the main circuit current value includes: I: When any current sensing component is found to be malfunctioning, the heating MOSFET is checked to see if it is in the off state.

[0061] II: If so, then based on the battery's current state of charge, temperature, and terminal voltage and internal resistance characteristics in a static state, determine the estimated current that should flow through the main circuit.

[0062] Here, the estimated current that should flow through the main circuit is determined using the following formula. :

[0063] Where U represents the total battery voltage obtained by accumulating the cell voltages. is the open-circuit voltage, and DCIR is the DC internal resistance.

[0064] III: Based on the first DC current, the second DC current, and the estimated current, perform a time-domain steady-state current deviation analysis, and select the main circuit current value according to the directionality and relative amplitude relationship of the deviation.

[0065] Here, a time-domain steady-state current deviation analysis is performed based on the first DC current, the second DC current, and the estimated current, and the main circuit current value is selected based on the directionality and relative amplitude of the deviation.

[0066] In one possible implementation, the step of performing time-domain steady-state current deviation analysis based on the first DC current, the second DC current, and the estimated current, and selecting the main circuit current value according to the directionality and relative amplitude of the deviation, includes: i: Compare the first DC current and the second DC current with the estimated current, respectively.

[0067] ii: If both the first DC current and the second DC current are close to the estimated current, or if the first DC current and the second DC current deviate from the estimated current in the same direction and the degree of deviation is within a preset deviation range, then the average value of the first DC current and the second DC current shall be used as the main circuit current value.

[0068] Here, the deviations between the first DC current and the second DC current and the estimated current are both within ±3%; or, the deviations between the first DC current and the second DC current and the estimated current are both positive or both negative. If the difference between the two currents is within 3%, then the average of the first DC current and the second DC current will be taken as the main circuit current value. The first DC current, This is the second DC current.

[0069] iii: If the above conditions are not met, then the DC current that is closer to the estimated current between the first DC current and the second DC current shall be selected as the main circuit current value.

[0070] It should be noted that if the above conditions are not met, it means that either the first DC current or the second DC current is not close to the estimated current, or either the first DC current or the second DC current deviates from the estimated current in a different direction, or the degree of deviation is not within the preset deviation range. In this case, the DC current that is closer to the estimated current between the first DC current and the second DC current shall be selected as the main circuit current value.

[0071] For a dual-sampling-point system, regardless of whether the heating MOSFET is on, since the battery heating circuit only has one linear heating resistor and does not introduce nonlinear components such as capacitors and inductors, the proportions of each frequency component decomposed from I1 and I2 in the frequency domain are theoretically not much different from the total harmonic distortion (THD). Only due to accuracy issues will there be deviations in the sampling values. Based on this, the I1 and I2 sampling signals can be decomposed using the aforementioned Fast Fourier Transform. For energy storage systems, since the harmonics introduced by the inverter rectifier switching frequency mainly consist of the 50Hz or 100Hz fundamental frequency, the proportions of the 50Hz and 100Hz harmonics at the two sampling points can be compared first. If the proportion of the 50Hz / 100Hz harmonics in a certain signal is significantly reduced, the sampling signal can be determined to be abnormal. Otherwise, when the heating MOSFET is off, a time-domain steady-state current deviation analysis is performed based on the first DC current, the second DC current, and the estimated current. The main circuit current value is then selected based on the directionality and relative amplitude of the deviation.

[0072] It should be noted that this application decouples the circuit using the KCL law: when the heating MOSFET is closed, the heating current is directly calculated using (I_h=I_1-I_2), and the heating status monitoring and four types of fault diagnosis, such as open circuit / adhesion / abnormal resistance, can be achieved without additional sensors; when the heating MOSFET is open, I1 and I2 automatically return to the dual-verification mode of the main circuit.

[0073] In this application, on the one hand, the heating MOSFET is closed during the heating process, and the heating circuit current can be calculated through the difference between the two currents for heating status monitoring and protection. On the other hand, when the heating MOSFET is open, the current is estimated using the battery open-circuit voltage (ocv) and DC internal resistance (DCIR), and then the actual current value of the system is obtained through cross-verification using dual-point current detection. Without increasing hardware costs, this approach satisfies the heating circuit current detection function while achieving cross-verification of dual current sampling, thus improving system reliability and functional safety.

[0074] This application provides a safety verification method for dual current sampling in an energy storage system. The method includes: setting a first current detection component at the positive terminal of the battery in a battery heating circuit, located outside the heating circuit; and setting a second current detection component at the negative terminal of the battery. Based on real-time acquisition of a first current sampling signal from the first current detection component and a second current sampling signal from the second current detection component, the heating circuit current is determined, and battery heating circuit status monitoring and fault diagnosis are performed based on the heating circuit current. Frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis are performed on the first and second current sampling signals to determine anomalies in the current detection components and dynamically select the main circuit current value. By performing battery heating circuit fault detection based on the heating circuit current, and simultaneously performing frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis, dual current sampling mutual verification is achieved, improving system reliability and functional safety without increasing the number of hardware current samples.

[0075] Please see Figure 3 , Figure 3 This is a schematic diagram of the structure of a safety verification device for dual current sampling in an energy storage system, provided as an embodiment of this application. Figure 3 As shown, the safety verification device 300 for dual current sampling of the energy storage system includes: The module 310 is configured to install a first current detection component at the positive terminal of the battery in the battery heating circuit and at a position outside the heating circuit, and to install a second current detection component at the negative terminal of the battery. The dual-current first detection module 320 is used to determine the heating circuit current based on the first current sampling signal of the first current detection component and the second current sampling signal of the second current detection component acquired in real time, and to perform battery heating circuit status monitoring and fault diagnosis based on the heating circuit current. The dual-current second detection module 330 is used to perform frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis on the first current sampling signal and the second current sampling signal, to determine the abnormality of the current detection component and dynamically select the main circuit current value.

[0076] Furthermore, the dual-current first detection module 320 is used to determine the heating circuit current based on the first current sampling signal of the first current detection component and the second current sampling signal of the second current detection component acquired in real time, and to perform battery heating circuit status monitoring and fault diagnosis based on the heating circuit current: The heating circuit current is determined based on the first current sampling signal and the second current sampling signal; When there is voltage between the positive and negative terminals of the battery and the heating MOSFET is in the closed state, if the current of the heating circuit is within the fault preset range, then the open circuit fault of the heating circuit is determined. When there is a voltage between the positive and negative terminals of the battery and the heating MOSFET is in the closed state, if the deviation between the resistance value of the heating resistor calculated based on Ohm's law and the rated resistance value exceeds the threshold, then the heating resistance value of the battery heating circuit is determined to be abnormal. When there is a voltage between the positive and negative terminals of the battery, the heating MOSFET is in a closed state, and the current of the heating circuit is within the preset normal range, if the measured temperature rise rate is lower than the expected threshold, it is determined that the heating film has detached. If the heating MOSFET receives a disconnect command or is in a disconnected state, and the heating circuit current remains greater than zero, then the heating MOSFET is determined to be stuck together.

[0077] Furthermore, the dual-current second detection module 330 is used to perform frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis on the first current sampling signal and the second current sampling signal to determine the abnormality of the current detection component and dynamically select the main circuit current value: Frequency component analysis and DC component extraction are performed on the first current sampling signal and the second current sampling signal to determine the first fundamental frequency and the first DC current of the first current sampling signal, and the second fundamental frequency and the second DC current of the second current sampling signal. Based on the first fundamental frequency and the second fundamental frequency, the consistency of frequency domain harmonic energy distribution is judged to determine the abnormality of the current detection component; Based on the first DC current and the second DC current, a time-domain steady-state current deviation analysis is performed to dynamically select the main circuit current value.

[0078] Furthermore, the dual-current second detection module 330 is used to determine the consistency of frequency domain harmonic energy distribution based on the first fundamental frequency and the second fundamental frequency, thereby identifying any abnormalities in the current detection component. The energy proportions of the first fundamental frequency and the second fundamental frequency in the overall fluctuation component are determined; The component energy ratio of the first fundamental frequency is compared with that of the second fundamental frequency. When the component energy ratio of either component is lower than that of the other component, and the difference reaches or exceeds a preset ratio threshold, the current detection component corresponding to the lower component energy ratio is determined to be malfunctioning.

[0079] Furthermore, the dual-current second detection module 330 is used to perform time-domain steady-state current deviation analysis based on the first DC current and the second DC current, and dynamically select the main circuit current value: When any current sensing component is found to be malfunctioning, the system checks whether the heating MOSFET is in an off state. If so, the estimated current that should flow through the main circuit is determined based on the battery's current state of charge, temperature, and terminal voltage and internal resistance characteristics in a static state. Based on the first DC current, the second DC current, and the estimated current, a time-domain steady-state current deviation analysis is performed, and the main circuit current value is selected according to the directionality and relative amplitude relationship of the deviation.

[0080] Furthermore, the dual-current second detection module 330 is used to perform time-domain steady-state current deviation analysis based on the first DC current, the second DC current, and the estimated current, and select the main circuit current value according to the directionality and relative amplitude relationship of the deviation. The first DC current and the second DC current are compared with the estimated current, respectively. If both the first DC current and the second DC current are close to the estimated current, or if the first DC current and the second DC current deviate from the estimated current in the same direction and the degree of deviation is within a preset deviation range, then the average value of the first DC current and the second DC current will be used as the main circuit current value. If the above conditions are not met, then the DC current that is closer to the estimated current between the first DC current and the second DC current shall be selected as the main circuit current value.

[0081] This application provides a safety verification device for dual-current sampling in an energy storage system. The device includes: a setting module for installing a first current detection component at the positive terminal of the battery in the battery heating circuit, located outside the heating circuit, and a second current detection component at the negative terminal of the battery; a dual-current first detection module for determining the heating circuit current based on the real-time acquired first current sampling signal from the first current detection component and the second current sampling signal from the second current detection component, and performing battery heating circuit status monitoring and fault diagnosis based on the heating circuit current; and a dual-current second detection module for performing frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis on the first and second current sampling signals, determining anomalies in the current detection components, and dynamically selecting the main circuit current value. By performing battery heating circuit fault detection based on the heating circuit current, and simultaneously performing frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis, dual-current sampling mutual verification is achieved, improving system reliability and functional safety without increasing the number of hardware current samples.

[0082] Please see Figure 4 , Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 4 As shown, the electronic device 400 includes a processor 410, a memory 420, and a bus 430.

[0083] The memory 420 stores machine-readable instructions executable by the processor 410. When the electronic device 400 is running, the processor 410 communicates with the memory 420 via the bus 430. When the machine-readable instructions are executed by the processor 410, they can perform the operations described above. Figure 1 The steps of the safety verification method for dual current sampling of the energy storage system in the method embodiment shown are described in detail in the method embodiment, and will not be repeated here.

[0084] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, can perform the above-described actions. Figure 1 The steps of the safety verification method for dual current sampling of the energy storage system in the method embodiment shown are described in detail in the method embodiment, and will not be repeated here.

[0085] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0086] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the shown or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0087] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0088] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0089] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0090] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The scope of protection of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A safety verification method for dual current sampling in an energy storage system, characterized in that, The security verification method includes: A first current detection component is installed at the positive terminal of the battery in the battery heating circuit and at a position outside the heating circuit, and a second current detection component is installed at the negative terminal of the battery. Based on the first current sampling signal of the first current detection component and the second current sampling signal of the second current detection component collected in real time, the heating circuit current is determined, and the battery heating circuit status is monitored and fault diagnosis is performed based on the heating circuit current. The first current sampling signal and the second current sampling signal are subjected to frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis to determine the abnormality of the current detection component and dynamically select the main circuit current value.

2. The security verification method according to claim 1, characterized in that, The process of determining the heating circuit current based on the first current sampling signal from the first current detection component and the second current sampling signal from the second current detection component acquired in real time, and performing battery heating circuit status monitoring and fault diagnosis based on the heating circuit current, includes: The heating circuit current is determined based on the first current sampling signal and the second current sampling signal; When there is voltage between the positive and negative terminals of the battery and the heating MOSFET is in the closed state, if the current of the heating circuit is within the fault preset range, then the open circuit fault of the heating circuit is determined. When there is a voltage between the positive and negative terminals of the battery and the heating MOSFET is in the closed state, if the deviation between the resistance value of the heating resistor calculated based on Ohm's law and the rated resistance value exceeds the threshold, then the heating resistance value of the battery heating circuit is determined to be abnormal. When there is a voltage between the positive and negative terminals of the battery, the heating MOSFET is in a closed state, and the current of the heating circuit is within the preset normal range, if the measured temperature rise rate is lower than the expected threshold, it is determined that the heating film has detached. If the heating MOSFET receives a disconnect command or is in a disconnected state, and the heating circuit current remains greater than zero, then the heating MOSFET is determined to be stuck together.

3. The security verification method according to claim 1, characterized in that, The step of performing frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis on the first current sampling signal and the second current sampling signal to determine the abnormality of the current detection component and dynamically select the main circuit current value includes: Frequency component analysis and DC component extraction are performed on the first current sampling signal and the second current sampling signal to determine the first fundamental frequency and the first DC current of the first current sampling signal, and the second fundamental frequency and the second DC current of the second current sampling signal. Based on the first fundamental frequency and the second fundamental frequency, the consistency of frequency domain harmonic energy distribution is judged to determine the abnormality of the current detection component; Based on the first DC current and the second DC current, a time-domain steady-state current deviation analysis is performed to dynamically select the main circuit current value.

4. The security verification method according to claim 3, characterized in that, The step of determining the consistency of frequency domain harmonic energy distribution based on the first fundamental frequency and the second fundamental frequency to identify abnormalities in the current detection component includes: The energy proportions of the first fundamental frequency and the second fundamental frequency in the overall fluctuation component are determined; The component energy ratio of the first fundamental frequency is compared with that of the second fundamental frequency. When the component energy ratio of either component is lower than that of the other component, and the difference reaches or exceeds a preset ratio threshold, the current detection component corresponding to the lower component energy ratio is determined to be malfunctioning.

5. The security verification method according to claim 3, characterized in that, The step of performing time-domain steady-state current deviation analysis based on the first DC current and the second DC current, and dynamically selecting the main circuit current value, includes: When any current sensing component is found to be malfunctioning, the system checks whether the heating MOSFET is in an off state. If so, the estimated current that should flow through the main circuit is determined based on the battery's current state of charge, temperature, and terminal voltage and internal resistance characteristics in a static state. Based on the first DC current, the second DC current, and the estimated current, a time-domain steady-state current deviation analysis is performed, and the main circuit current value is selected according to the directionality and relative amplitude relationship of the deviation.

6. The security verification method according to claim 5, characterized in that, The step of performing time-domain steady-state current deviation analysis based on the first DC current, the second DC current, and the estimated current, and selecting the main circuit current value according to the directionality and relative amplitude of the deviation, includes: The first DC current and the second DC current are compared with the estimated current, respectively. If both the first DC current and the second DC current are close to the estimated current, or if the first DC current and the second DC current deviate from the estimated current in the same direction and the degree of deviation is within a preset deviation range, then the average value of the first DC current and the second DC current will be used as the main circuit current value. If the above conditions are not met, then the DC current that is closer to the estimated current between the first DC current and the second DC current shall be selected as the main circuit current value.

7. The security verification method according to claim 1, characterized in that, The battery heating circuit includes a battery, a charging MOSFET, a discharging MOSFET, a heating MOSFET, an energy management system, and a heating resistor; wherein, The negative terminal of the battery is electrically connected to the drain of the charging MOSFET, the source of the charging MOSFET is electrically connected to the drain of the discharging MOSFET, the source of the discharging MOSFET is electrically connected to the first terminal of the heating resistor, the second terminal of the heating resistor is electrically connected to the drain of the heating MOSFET, and the source of the heating MOSFET is electrically connected to the positive terminal of the battery. Furthermore, the gates of the charging MOSFET, the discharging MOSFET, and the heating MOSFET are all electrically connected to the energy management system.

8. A safety verification device for dual current sampling in an energy storage system, characterized in that, The security verification device includes: The module is configured to install a first current detection component at the positive terminal of the battery in the battery heating circuit and at a position outside the heating circuit, and to install a second current detection component at the negative terminal of the battery. The dual-current first detection module is used to determine the heating circuit current based on the first current sampling signal of the first current detection component and the second current sampling signal of the second current detection component acquired in real time, and to perform battery heating circuit status monitoring and fault diagnosis based on the heating circuit current. The dual-current second detection module is used to perform frequency domain harmonic energy distribution consistency judgment and time domain steady-state current deviation analysis on the first current sampling signal and the second current sampling signal, to determine the abnormality of the current detection component and dynamically select the main circuit current value.

9. An electronic device, characterized in that, include: The device includes a processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor communicates with the memory via the bus. The machine-readable instructions are executed by the processor to perform the steps of the security verification method for dual current sampling of an energy storage system as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, performs the steps of the security verification method for dual current sampling of an energy storage system as described in any one of claims 1 to 7.

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