Energy storage device

Abstract

The utility model discloses an energy storage device comprising a battery module, the battery module comprises a power supply loop and a sampling resistor, and the sampling resistor is arranged in the power supply loop; the analog front end is used for collecting voltage information at the two ends of the sampling resistor; and the buffer circuit is arranged between the sampling resistor and the analog front end, the buffer circuit is connected with the analog front end, and the buffer circuit comprises a capacitor. The capacitor in the buffer circuit absorbs and filters high voltage causing abnormal oscillation of the energy storage device, namely filters disturbance of the high voltage, and smooths waveforms of voltage signals at two ends of the sampling resistor, so that oscillation of the energy storage device caused by interference voltage is avoided, and the stability of the system is improved.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage power supplies, and more specifically, to an energy storage device. Background Art

[0002] At present, when energy storage devices with larger energy storage capacity store and transmit electric energy based on high-voltage technology, due to the large energy content of the battery pack of the energy storage device, high voltage will be generated in the circuit at the moment the circuit is shut down, causing voltage disturbance in the circuit. The voltage during voltage disturbance is usually greater than the voltage threshold that the electronic components of the energy storage device can withstand, which in turn causes abnormal oscillation in the circuit of the energy storage device, affecting the stability of the energy storage device. Summary of the Invention

[0003] The embodiments of the present application provide an energy storage device that can avoid abnormal oscillations in the circuit of the energy storage device and improve the stability of the energy storage device.

[0004] The energy storage device of the present application includes: a battery module, the battery module including a power supply circuit and a sampling resistor, the sampling resistor being arranged in the power supply circuit; an analog front end, the analog front end being used to collect voltage information across the sampling resistor; and a buffer circuit, the buffer circuit being arranged between the sampling resistor and the analog front end, the buffer circuit being connected to the analog front end, and the buffer circuit including a capacitor.

[0005] In some embodiments, the capacitor includes a common-mode capacitor, one end of the common-mode capacitor is connected to the sampling resistor and the analog front end, and the other end is grounded.

[0006] In some embodiments, the common-mode capacitor includes a first common-mode capacitor and a second common-mode capacitor, each of the first common-mode capacitor and the second common-mode capacitor includes a plurality of capacitors, the first common-mode capacitor is connected to the current input end of the sampling resistor, and the second common-mode capacitor is connected to the current output end of the sampling resistor.

[0007] In some embodiments, the capacitor further includes a diode, and the diode is connected in parallel with the common-mode capacitor.

[0008] In some embodiments, the buffer circuit further includes a buffer resistor, which is arranged between the sampling resistor and the analog front end, and one end of the buffer resistor is connected to the sampling resistor, and the other end is connected to the analog front end.

[0009] In some embodiments, the buffer resistor includes a plurality of buffer resistors, and the buffer resistors are connected between the current input end of the sampling resistor and the analog front end, and between the current output end of the sampling resistor and the analog front end.

[0010] In some embodiments, the analog front end includes a first sampling pin and a second sampling pin, the first sampling pin and the second sampling pin are respectively connected to the current input end and the current output end of the sampling resistor, and the capacitor also includes a differential mode capacitor, the two ends of the differential mode capacitor are respectively connected to the first sampling pin and the second sampling pin.

[0011] In some embodiments, the energy storage device includes a metal oxide semiconductor field effect transistor. When the voltage collected by the analog front end is greater than a preset short-circuit voltage threshold and lasts for a first preset time, the metal oxide semiconductor field effect transistor is disconnected, wherein the first preset time is the same as the response delay of the analog front end.

[0012] In some embodiments, the energy storage device further includes a metal oxide semiconductor field effect transistor and a bleeder circuit, the bleeder circuit including a bleeder resistor, the resistance of the bleeder resistor being a preset resistance value, wherein when the resistance value of the bleeder resistor is the preset resistance value, the metal oxide semiconductor field effect transistor is turned off within a second preset time period.

[0013] In some embodiments, the analog front end includes a signal acquisition line, and the signal acquisition line is wrapped by a metal shielding material.

[0014] The energy storage device of the embodiment of the present application includes a battery module, an analog front end, and a buffer circuit. The battery module includes a power supply circuit and a sampling resistor, and the sampling resistor is arranged in the power supply circuit; the analog front end is used to collect voltage information across the sampling resistor; the buffer circuit is arranged between the sampling resistor and the analog front end, and the buffer circuit is connected to the analog front end, and the buffer circuit includes a capacitor. The capacitor in the buffer circuit absorbs and filters out high voltages that cause abnormal oscillations in the energy storage device, that is, filters out high voltage disturbances, and smoothes the waveform of the voltage signal across the sampling resistor to avoid oscillations in the energy storage device caused by interference voltage, thereby improving the stability of the system.

[0015] Additional aspects and advantages of the embodiments of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0017] Figure 1 is a schematic structural diagram of an energy storage device according to certain embodiments of the present application;

[0018] Figure 2 is a schematic diagram of a scenario of an energy storage device according to certain embodiments of the present application;

[0019] Figure 3 is a schematic diagram of a scenario of an energy storage device according to certain embodiments of the present application;

[0020] Figure 4 is a schematic structural diagram of an energy storage device according to certain embodiments of the present application;

[0021] Figure 5 is a schematic diagram of a scenario of an energy storage device according to certain embodiments of the present application;

[0022] Figure 6 is a schematic diagram of a scenario of an energy storage device according to certain embodiments of the present application;

[0023] Figure 7 It is a structural schematic diagram of the energy storage device of certain embodiments of the present application. DETAILED DESCRIPTION

[0024] The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the embodiments of the present application, and should not be understood as limiting the embodiments of the present application.

[0025] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, features defined as "first" or "second" may explicitly or implicitly include at least one feature. In the description of this application, "plurality" means at least two, for example, two or three, unless otherwise specifically defined.

[0027] To facilitate understanding of this application, the following is an introduction to the background technology of this application:

[0028] Energy storage devices with larger energy storage capacity (e.g., 5 kWh) have a wider range of applications than those with smaller energy storage capacity (e.g., 2 kWh). Larger capacity can provide longer-term power supply or support higher power demands.

[0029] Currently, energy storage devices can be based on low-voltage technology, using relatively low voltages to store and transmit electrical energy during the charging and discharging process. For energy storage devices with larger storage capacities, to ensure the transmitted power, the circuits need to carry higher currents during energy storage and transmission, resulting in greater line losses and higher costs for the energy storage devices. While energy storage devices based on high-voltage technology can avoid these problems, due to the high energy content of the battery packs in energy storage devices, inductive loads (such as inductors or transformers) in the energy storage device circuits can generate high voltage spikes when the energy storage device shuts down. (Due to their inherent inductance, inductive loads attempt to maintain current continuity. According to the principle of inductance, when the current changes rapidly, a reverse electromotive force is generated, causing voltage spikes.) This leads to voltage disturbances. The voltage during voltage disturbances is often greater than the voltage threshold that the electronic components of the energy storage device can withstand, causing abnormal oscillations in the energy storage device circuits and affecting the stability of the energy storage device.

[0030] In order to solve the above technical problems, an embodiment of the present application provides an energy storage device.

[0031] The energy storage device of this application will be described in detail below:

[0032] See also Figure 1 , the energy storage device 100 of the embodiment of the present application includes:

[0033] The battery module 10 includes a power supply circuit and a sampling resistor 11, and the sampling resistor 11 is arranged in the power supply circuit;

[0034] The analog front end 20 is used to collect voltage information across the sampling resistor 11;

[0035] The buffer circuit 30 is provided between the sampling resistor 11 and the analog front end 20 . The buffer circuit 30 is connected to the analog front end 20 . The buffer circuit 30 includes a capacitor.

[0036] Specifically, see Figure 1Energy storage device 100 can power a load 70 and includes a battery module 10, an analog front end 20, and a buffer circuit 30. Battery module 10 can power the load based on the voltage generated by the battery pack. Battery module 10 includes a power supply circuit and a sampling resistor 11. The sampling resistor 11 is disposed within the power supply circuit. The analog front end 20 (AFE) can collect voltage information across the sampling resistor 11 to determine the current and power in the power supply circuit.

[0037] Optionally, the energy storage device 100 further includes a metal oxide semiconductor field effect transistor 40 and a discharge circuit 50 , and the discharge circuit includes a discharge resistor 51 .

[0038] Specifically, the energy storage device 100 further includes a metal-oxide-semiconductor field-effect transistor (MOS transistor). Figure 2 The energy storage device 100 includes two MOS transistors 40. The energy storage device 100 can be powered on and off by controlling the on and off of the MOS transistors 40. The bleeder circuit 50 can control the on and off of the MOS transistors 40 (the bleeder circuit 50 can discharge the charge of the MOS transistors 40 to turn off the MOS transistors 40), and the bleeder resistor 51 can adjust the delay time of the on and off of the MOS transistors 40 (for example, the larger the resistance of the bleeder resistor, the slower the charging time of the capacitor between the gate and source of the MOS transistor, and the longer the time to turn off the MOS transistor).

[0039] The analog front end 20 can control the bleeder circuit 50 to indirectly control the on / off of the MOS transistor 40. For example, by setting a short-circuit voltage threshold, when the voltage collected by the analog front end 20 is greater than the short-circuit voltage threshold, the short-circuit protection is triggered, and the analog front end 20 controls the bleeder circuit to disconnect the MOS transistor 40.

[0040] Since the energy storage device 100 has a large amount of energy, turning off the MOS tube 40 to disconnect the power supply circuit will cause voltage disturbance. Figure 2 , the disturbed voltage can reach 3.6 volts (V), which is much larger than the maximum voltage that the sampling pin of the analog front end 20 can usually withstand (usually 1.8V), such as Figure 2 As shown in FIG, the maximum voltage of the sampling pin of the analog front end 20 has reached 6.25V, which is also much greater than the voltage threshold that the analog front end 20 can withstand, which will cause the analog front end 20 to reset. After the analog front end 20 is reset, it will continue to connect to the MOS tube 40. However, when the MOS tube 40 is connected, the voltage collected by the analog front end 20 will be too large again, which will trigger the short-circuit protection and disconnect the MOS tube 40. Therefore, the analog front end 20 will be reset continuously (as shown in FIG). Figure 3As shown, the voltage of the MOS tube 40 and the voltage of the load 70 are constantly changing, and the total current value of the power supply circuit is in a large range), causing abnormal oscillation of the energy storage device 100, affecting the system stability of the energy storage device 100.

[0041] Therefore, a buffer circuit 30 can be provided for the energy storage device 100. The buffer circuit 30 is provided between the sampling resistor 11 and the analog front end 20. The buffer circuit 30 is connected to the analog front end 20. The buffer circuit 30 includes a capacitor. The capacitor in the buffer circuit 30 absorbs and filters out the high voltage that causes abnormal oscillation of the energy storage device 100, that is, filters out the high voltage disturbance, and smoothes the waveform of the voltage signal across the sampling resistor 11 to avoid oscillation of the energy storage device 100 caused by interference voltage, thereby improving system stability.

[0042] Optionally, see Figure 4 The analog front end 20 includes a first sampling pin 21 and a second sampling pin 22 .

[0043] In some embodiments, the energy storage device 100 includes a metal oxide semiconductor field effect transistor. When the voltage collected by the analog front end 20 is greater than a preset short-circuit voltage threshold and lasts for a first preset time, the metal oxide semiconductor field effect transistor is disconnected, wherein the first preset time is the same as the response delay time of the analog front end 20.

[0044] Specifically, the short-circuit protection of the energy storage device 100 is usually set with a response delay (i.e., a first preset duration) to prevent misjudgment of a short circuit due to voltage (or current) interference. A preset short-circuit voltage threshold or a preset short-circuit current threshold can be set. When the voltage collected by the analog front end 20 is greater than the preset short-circuit voltage threshold, or the current calculated based on the voltage collected by the analog front end 20 is greater than the preset short-circuit current threshold, and continues for a first preset duration, the short-circuit protection of the energy storage device 100 is triggered. For example, taking the first preset duration as 200 microseconds (us) and the preset short-circuit current threshold as 600 amperes (A), when the current value in the power supply circuit is determined to be greater than 600A based on the voltage collected by the analog front end 20, and the duration of the current value greater than 600A is greater than 200us, the short-circuit protection is triggered and the MOS tube 40 is disconnected. Since the current in the power supply circuit of the energy storage device 100 gradually rises to a larger value during a short circuit, in other words, the analog front end 20 will collect a larger voltage value, thereby causing the energy storage device 100 to oscillate abnormally. To prevent the analog front end 20 from falsely triggering the voltage signal, the analog front end 20 typically sets a response delay (typically 50 μs), meaning it responds to the collected voltage after the response delay. Therefore, the first preset duration for triggering the short-circuit protection can be set to the preset response delay of the analog front end 20, reducing the maximum current rise that can reach before the short circuit is triggered. This reduces the voltage value collected by the analog front end 20 when the short-circuit protection is triggered.

[0045] See also Figure 4 In some embodiments, the energy storage device 100 further includes a metal oxide semiconductor field effect transistor and a bleeder circuit 50. The bleeder circuit 50 includes a bleeder resistor 51. The resistance value of the bleeder resistor 51 is a preset resistance value. When the resistance value of the bleeder resistor 51 is the preset resistance value, the metal oxide semiconductor field effect transistor is turned off within a second preset time period.

[0046] Specifically, as mentioned above, the resistance of the bleeder resistor 51 affects the turn-off time of the MOS transistor 40. When the resistance of the bleeder resistor 51 is 0, the turn-off time of the MOS transistor 40 is the shortest. However, if the turn-off time of the MOS transistor 40 is too short, the voltage change rate U=du / dt on the power supply circuit will be relatively large, which will also cause voltage interference and oscillation. The turn-off time of the MOS transistor 40 can be determined based on empirical values ​​or experimental values. For example, see Figure 5 and Figure 6 Assuming that the discharge resistance is 510R, the current of the power supply circuit of the energy storage device 100 is as follows: Figure 5 As shown, at this time, the maximum current in the power supply circuit is 1.64 kiloamperes (kA). When the discharge resistor is 820R, the current of the power supply circuit of the energy storage device 100 is as follows: Figure 6 As shown, at this time, the maximum current in the power supply circuit is 1.85 kiloamperes (kA). Assuming that both resistors can meet the requirement of avoiding oscillation of the energy storage device 100, in order to ensure the shortest possible shutdown time, a 510R discharge resistor can be selected.

[0047] For another example, based on experiments, table lookup, etc., it is determined that the turn-off time of the MOS tube 40 is 100 μs, which minimizes the interference to the energy storage device 100. The capacitor discharge time t of the MOS tube 40 can be calculated by the formula:

[0048] t=RC×ln(E / V t )

[0049] Wherein, E is the voltage difference between the initial discharge voltage and the voltage at the end of discharge of the capacitor of the MOS tube 40, Vt is the voltage difference between the voltage at time t and the initial discharge voltage, R is the discharge resistance value, and C is the capacitance value.

[0050] Therefore, based on the above formula, the preset resistance value of the bleeder resistor 51 can be determined. When the resistance value of the bleeder resistor 51 is the preset resistance value, the MOS tube 40 is turned off within the second preset time length (t), and the interference to the energy storage device 100 is relatively small.

[0051] See also Figure 4 In some embodiments, the capacitor includes a common-mode capacitor, one end of which is connected to the sampling resistor 11 and the analog front end 20, and the other end is grounded.

[0052] Optionally, the common-mode capacitor includes a first common-mode capacitor 311 and a second common-mode capacitor 312 , each of the first common-mode capacitor 311 and the second common-mode capacitor 312 includes multiple capacitors, the first common-mode capacitor 311 is connected to the current input end of the sampling resistor 11 , and the second common-mode capacitor 312 is connected to the current output end of the sampling resistor 11 .

[0053] Specifically, see Figure 4 The analog front end 20 includes a first sampling pin 21 and a second sampling pin 22, and the common-mode capacitor includes a first common-mode capacitor 311 and a second common-mode capacitor 312. The first common-mode capacitor 311 and the second common-mode capacitor 312 each include a plurality of capacitors. The current input end and the current output end of the sampling resistor 11 are both connected to the common-mode capacitor, that is, one end of the common-mode capacitor is connected to the current input end of the sampling resistor 11 and the first sampling pin of the analog front end 20, and the other end is connected to the current output end of the sampling resistor 11 and the second sampling pin of the analog front end 20.

[0054] like Figure 1As shown, the common-mode capacitors include a first common-mode capacitor 311 and a second common-mode capacitor 312. The two first common-mode capacitors 311 are connected in parallel to form a common-mode loop, one end of which is connected to the current input end of the sampling resistor 11 and the first sampling pin 21 of the analog front end 20, and the other end is grounded. The two second common-mode capacitors 312 are connected in parallel to form a common-mode loop, one end of which is connected to the current output end of the sampling resistor 11 and the second sampling pin 22 of the analog front end 20, and the other end is grounded. The energy storage device 100 has a large amount of energy. When the MOS transistor 40 is turned off, the energy is converted into a high voltage that can cause abnormal oscillations in the energy storage device 100. High voltages are usually manifested as high-frequency signals. Grounding the common-mode capacitors 31 can guide high-frequency voltage spikes to ground, thereby reducing the impact on the analog front end 20 and alleviating the impact on voltage measurement.

[0055] Optionally, the capacitor further includes a diode, and the diode and the common-mode capacitor 31 are connected in parallel.

[0056] The diode is a Schottky diode 32 (a hot carrier diode).

[0057] Specifically, if Figure 4 As shown, in the battery module, a Schottky diode 32 is connected in parallel with the common-mode capacitor 31. When voltage fluctuations or voltage spikes exceed the turn-on voltage of the Schottky diode 32 (generally less than 0.5V, for example, 0.15V, 0.2V, 0.3V, 0.4V, etc.), the Schottky diode 32 will quickly turn on, directing the voltage to ground and clamping the voltage. Since the turn-on voltage of the Schottky diode 32 is low, the clamping effect can be guaranteed.

[0058] In some embodiments, the buffer circuit further includes a buffer resistor 60 , which is disposed between the sampling resistor 11 and the analog front end 20 . One end of the buffer resistor 60 is connected to the sampling resistor 11 , and the other end is connected to the analog front end 20 .

[0059] Optionally, the buffer resistor 60 includes multiple ones, and the buffer resistor 60 is connected between the current input end of the sampling resistor 11 and the analog front end 20, and between the current output end of the sampling resistor 11 and the analog front end 20. One end of the common-mode capacitor is connected to the buffer resistor 60 and the analog front end 20, and the other end is grounded.

[0060] Specifically, see Figure 4 The buffer circuit further includes a buffer resistor 60, and the buffer resistor 60 includes multiple Figure 1As shown, two buffer resistors 60 are respectively provided between the current input terminal of the sampling resistor 11 and the analog front end 20, and between the current output terminal of the sampling resistor 11 and the analog front end 20. By introducing the buffer resistors 60 between the sampling resistor 11 and the analog front end 20, the voltage on the sampling resistor 11 is shared by the buffer resistors 60, thereby reducing the voltage collected by the analog front end 20 during voltage disturbances and improving the stability of the energy storage device.

[0061] See also Figure 4 Optionally, the analog front end 20 includes a first sampling pin 21 and a second sampling pin 22, which are respectively connected to the current input end and the current output end of the sampling resistor 11, and the capacitor also includes a differential mode capacitor 33, and the two ends of the differential mode capacitor 33 are respectively connected to the first sampling pin 21 and the second sampling pin 22.

[0062] Specifically, in order to prevent the voltage difference between the two ends of the analog front end 20 (i.e., the first sampling pin 21 and the second sampling pin 22) from being too large and damaging the analog front end 20, one or more differential mode capacitors 33 (such as Figure 1 As shown, two differential mode capacitors 33 are connected at both ends of the analog front end 20. When the voltage between the first sampling pin 21 and the second sampling pin 22 changes suddenly or the voltage difference is too large, the differential mode capacitors 33 can temporarily store charge to slow down the rate of voltage change and smooth the voltage change, thereby reducing the impact on the analog front end 20 and further stabilizing the energy storage device.

[0063] In some embodiments, the analog front end 20 includes a signal acquisition line, and the signal acquisition line is wrapped by a metal shielding material.

[0064] The metal shielding material may be copper, lead or other materials.

[0065] Specifically, when the signal acquisition line is exposed to the air, it may be interfered by the radiation in the air, which may also cause system oscillation. Figure 7 For example, if a PCB consists of four layers and L2 is covered with ground material, the ground plane cannot directly absorb or shield the radiation from the signal lines if the signal acquisition lines are placed on L1 and L4, causing the signal lines to interfere with the power supply circuit. If the signal acquisition line is placed on L3, the interference signal will also be transmitted to the sampling pins of the analog front end, causing system oscillation. Therefore, the signal acquisition line can be placed on L2, so that the signal acquisition line is covered with metal shielding material (such as copper) to prevent spatial radiation interference.

[0066] In the description of this specification, the reference terms "certain embodiments", "in an example", "exemplarily", etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are mutually inconsistent.

[0067] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0068] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. An energy storage device, characterized in that: include: A battery module, the battery module comprising a power supply circuit and a sampling resistor, wherein the sampling resistor is arranged in the power supply circuit; An analog front end, configured to collect voltage information across the sampling resistor; A buffer circuit is provided between the sampling resistor and the analog front end, the buffer circuit is connected to the analog front end, and the buffer circuit includes a capacitor.

2. The energy storage device according to claim 1, characterized in that The capacitor includes a common-mode capacitor, one end of which is connected to the sampling resistor and the analog front end, and the other end of which is grounded.

3. The energy storage device according to claim 2, characterized in that The common-mode capacitor includes a first common-mode capacitor and a second common-mode capacitor, each of the first common-mode capacitor and the second common-mode capacitor includes a plurality of capacitors. The first common-mode capacitor is connected to the current input end of the sampling resistor, and the second common-mode capacitor is connected to the current output end of the sampling resistor.

4. The energy storage device according to claim 2 or 3, characterized in that: The capacitor further includes a diode, and the diode is connected in parallel with the common-mode capacitor.

5. The energy storage device according to claim 1, characterized in that The buffer circuit further includes a buffer resistor, which is arranged between the sampling resistor and the analog front end. One end of the buffer resistor is connected to the sampling resistor, and the other end is connected to the analog front end.

6. The energy storage device according to claim 5, characterized in that The buffer resistors include a plurality of buffer resistors, and the buffer resistors are connected between the current input end of the sampling resistor and the analog front end, and between the current output end of the sampling resistor and the analog front end.

7. The energy storage device according to claim 1, characterized in that The analog front end includes a first sampling pin and a second sampling pin, the first sampling pin and the second sampling pin are respectively connected to the current input end and the current output end of the sampling resistor, and the capacitor also includes a differential mode capacitor, the two ends of the differential mode capacitor are respectively connected to the first sampling pin and the second sampling pin.

8. The energy storage device according to claim 1, characterized in that The energy storage device includes a metal oxide semiconductor field effect transistor. When the voltage collected by the analog front end is greater than a preset short-circuit voltage threshold and lasts for a first preset time, the metal oxide semiconductor field effect transistor is disconnected, wherein the first preset time is the same as the response delay of the analog front end.

9. The energy storage device according to claim 1, characterized in that The energy storage device also includes a metal oxide semiconductor field effect transistor and a bleeder circuit, the bleeder circuit includes a bleeder resistor, and the resistance value of the bleeder resistor is a preset resistance value. When the resistance value of the bleeder resistor is the preset resistance value, the metal oxide semiconductor field effect transistor is turned off within a second preset time period.

10. The energy storage device according to claim 1, characterized in that The analog front end includes a signal acquisition line, and the signal acquisition line is wrapped by a metal shielding material.

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