Power battery capacitance detection method and device, storage medium and electronic device

Abstract

The application discloses a kind of capacitors detection method, device, storage medium and electronic device of power battery, it is related to vehicle technical field.Therein, the method includes: receiving target control instruction, according to preset order control switch conduction state, determine the first voltage of first resistance, the second voltage of second resistance, the third voltage of third resistance and the fourth voltage of fourth resistance, wherein, first resistance, second resistance, third resistance and fourth resistance are located outside power battery, and power battery includes target capacitor;According to first voltage, second voltage, third voltage, fourth voltage and equivalent resistance value determine target capacitor value of target capacitor;Target capacitor is detected based on target capacitor value.The present application solves the technical problem that related art Y capacitor detection is established on the basis of important assumptions by being directed to the power battery inside electric vehicle, resulting in method being subject to, not easy to implement, and the detection accuracy is lower.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and more specifically, to a method, apparatus, storage medium, and electronic device for detecting the capacitance of a power battery. Background Technology

[0002] With the rapid development of electric vehicles, the safety and reliability of the high-voltage system, a key feature of electric vehicles, are receiving increasing attention. Due to electromagnetic interference and environmental factors, a capacitance, known as a Y-capacitor, exists between the high-voltage and low-voltage systems. This often presents a safety hazard of electric shock in the high-voltage system of electric vehicles. Therefore, accurate detection of the Y-capacitor is essential to ensure that the energy stored in it does not lead to electric shock.

[0003] Currently, the method involves testing the Y-capacitor in the high-voltage assembly of the on-board rechargeable energy storage system (REESS) inside electric vehicles, i.e., the power battery. This is done by constructing a circuit including the power battery, Y-capacitor, insulation resistance, balancing resistance, discharge resistance, and a switch, observing and recording the voltage change characteristics of the Y-capacitor, and then analyzing and calculating its specific value. However, this method relies on a crucial assumption, making it difficult to implement, and this assumption often fails. Furthermore, the accuracy of the resistor itself and the cumulative effect of deviations can negatively impact the Y-capacitor results, leading to low detection accuracy.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] This invention provides a method, apparatus, storage medium, and electronic device for detecting the capacitance of a power battery, thereby at least solving the technical problems of related technologies that rely on important assumptions to detect the Y-capacitance of power batteries inside electric vehicles, resulting in methods that are limited, difficult to implement, and have low detection accuracy.

[0006] According to one embodiment of the present invention, a method for detecting the capacitance of a power battery is provided, comprising: receiving a target control command; controlling the conduction state of a switch according to a preset sequence; determining a first voltage of a first resistor, a second voltage of a second resistor, a third voltage of a third resistor, and a fourth voltage of a fourth resistor, wherein the first resistor, the second resistor, the third resistor, and the fourth resistor are located outside the power battery, and the power battery includes a target capacitor; determining a target capacitance value of the target capacitor based on the first voltage, the second voltage, the third voltage, the fourth voltage, and an equivalent resistance value, wherein the equivalent resistance value is the equivalent resistance value of the first resistor, the second resistor, the fifth resistor, and the sixth resistor, and wherein the power battery further includes a fifth resistor and a sixth resistor; and detecting the target capacitor based on the target capacitance value.

[0007] Optionally, determining the target capacitance value of the target capacitor based on the first voltage, second voltage, third voltage, fourth voltage, and equivalent resistance value includes: determining a first current based on a fifth voltage and the resistance value of the third resistor, and determining a second current based on a sixth voltage and the resistance value of the fourth resistor, wherein the first current is the current of the third resistor, the second current is the current of the fourth resistor, and the fifth voltage and sixth voltage are the transient voltages of the first resistor and the second resistor, respectively; performing a first deformation process on the first current based on the equivalent resistance value to determine a first target current, and performing a second deformation process on the second current based on the equivalent resistance value to determine a second target current; processing the first target current based on the first voltage and the third voltage to determine a first target voltage, and processing the second target current based on the second voltage and the fourth voltage to determine a second target voltage; and determining the target capacitance value based on the first target voltage and the second target voltage.

[0008] Optionally, processing the first target current based on the first voltage and the third voltage to determine the first target voltage, and processing the second target current based on the second voltage and the fourth voltage to determine the second target voltage, includes: performing a third deformation process on the first current based on the first voltage and the third voltage to obtain a first initial voltage, and performing a fourth deformation process on the second current based on the second voltage and the fourth voltage to obtain a second initial voltage; performing a fifth deformation process on the first initial voltage based on a first time point to obtain the first target voltage, and performing a sixth deformation process on the second initial voltage based on a second time point to obtain the second target voltage, wherein the first time point and the second time point are outside a preset time period after the initial time point.

[0009] Optionally, determining the target capacitance value based on the first target voltage and the second target voltage includes: canceling the equivalent resistance value based on the first target voltage and the second target voltage to obtain the target capacitance value.

[0010] Optionally, the target control command includes a first control command, a second control command, and a third control command. Upon receiving the target control command, the conduction state of the switches is controlled according to a preset sequence to determine the first voltage of the first resistor, the second voltage of the second resistor, the third voltage of the third resistor, and the fourth voltage of the fourth resistor. This includes: upon receiving the first control command, determining the first voltage of the first resistor and the second voltage of the second resistor, wherein the first control command is used to control the first switch, the second switch, and the third switch to all be on; upon receiving the second control command, determining the third voltage of the third resistor, wherein the second control command is used to control the first switch, the second switch, the third switch, and the fourth switch to all be on, and the fourth switch is used to control the third resistor to be connected in parallel with the first resistor; upon receiving the third control command, determining the fourth voltage of the fourth resistor, wherein the second control command is used to control the first switch, the second switch, the third switch, and the fifth switch to all be on, and the fifth switch is used to control the fourth resistor to be connected in parallel with the second resistor.

[0011] Optionally, the method further includes: determining the total voltage of the power battery; and reporting an error message in response to the fact that the difference between the sum of the voltages of the first resistor and the voltages of the second resistor and the total voltage is greater than or equal to a first voltage threshold, the voltage fluctuation of the first resistor is greater than or equal to a second voltage threshold, and the voltage fluctuation of the second resistor is greater than or equal to the second voltage threshold, wherein the error message is used to indicate an error in the detection process.

[0012] According to one embodiment of the present invention, a capacitance detection circuit for a power battery is also provided, comprising: a power battery, a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a first resistor, a second resistor, a third resistor, and a fourth resistor. The power battery includes a battery, a fifth resistor, a sixth resistor, and a target capacitor. The positive terminal of the power battery is coupled to a first terminal of the first switch. The second terminal of the first switch is coupled to a first terminal of the first resistor. The second terminal of the first resistor is coupled to a first terminal of the third switch. The second terminal of the third switch is coupled to a ground terminal of the power battery. The first terminal of the first resistor is coupled to a first terminal of the fourth switch. The second terminal of the fourth switch is coupled to a first terminal of the third resistor. The second terminal of the third resistor is coupled to a first terminal of the fourth resistor. The second terminal of the fourth resistor is coupled to a first terminal of the fifth switch. The second terminal of the fifth switch is coupled to a first terminal of the second switch. The second terminal of the second switch is coupled to the negative terminal of the power battery. The second terminal of the first resistor is coupled to a first terminal of the second resistor. The second terminal of the second resistor is coupled to a first terminal of the second switch. The first terminal of the third switch is grounded.

[0013] According to one embodiment of the present invention, a capacitance detection device for a power battery is also provided, comprising: a control module, configured to receive a target control command, control the conduction state of switches according to a preset sequence, and determine a first voltage of a first resistor, a second voltage of a second resistor, a third voltage of a third resistor, and a fourth voltage of a fourth resistor, wherein the first resistor, the second resistor, the third resistor, and the fourth resistor are located outside the power battery, and the power battery includes a target capacitor; a determination module, configured to determine a target capacitance value of the target capacitor based on the first voltage, the second voltage, the third voltage, the fourth voltage, and an equivalent resistance value, wherein the equivalent resistance value is the equivalent resistance value of the first resistor, the second resistor, the fifth resistor, and the sixth resistor, and the power battery further includes a fifth resistor and a sixth resistor; and a detection module, configured to detect the target capacitor based on the target capacitance value.

[0014] Optionally, the determining module is further configured to determine a first current based on a fifth voltage and the resistance value of a third resistor, and to determine a second current based on a sixth voltage and the resistance value of a fourth resistor, wherein the first current is the current of the third resistor, the second current is the current of the fourth resistor, and the fifth voltage and the sixth voltage are the transient voltages of the first resistor and the second resistor, respectively; to perform a first deformation processing on the first current based on the equivalent resistance value to determine a first target current, and to perform a second deformation processing on the second current based on the equivalent resistance value to determine a second target current; to process the first target current based on the first voltage and the third voltage to determine a first target voltage, and to process the second target current based on the second voltage and the fourth voltage to determine a second target voltage; and to determine a target capacitance value based on the first target voltage and the second target voltage.

[0015] Optionally, the determining module is further configured to perform a third deformation process on the first current based on the first voltage and the third voltage to obtain a first initial voltage, and perform a fourth deformation process on the second current based on the second voltage and the fourth voltage to obtain a second initial voltage; perform a fifth deformation process on the first initial voltage based on a first moment to obtain a first target voltage, and perform a sixth deformation process on the second initial voltage based on a second moment to obtain a second target voltage, wherein the first moment and the second moment are outside a preset time period after the initial moment.

[0016] Optionally, the determining module is further configured to perform cancellation processing on the equivalent resistance value based on the first target voltage and the second target voltage to obtain the target capacitance value.

[0017] Optionally, the determining module is further configured to receive a first control instruction and determine a first voltage of the first resistor and a second voltage of the second resistor, wherein the first control instruction is used to control the first switch, the second switch, and the third switch to all be turned on; receive a second control instruction and determine a third voltage of the third resistor, wherein the second control instruction is used to control the first switch, the second switch, the third switch, and the fourth switch to all be turned on, and the fourth switch is used to control the third resistor to be connected in parallel with the first resistor; receive a third control instruction and determine a fourth voltage of the fourth resistor, wherein the second control instruction is used to control the first switch, the second switch, the third switch, and the fifth switch to all be turned on, and the fifth switch is used to control the fourth resistor to be connected in parallel with the second resistor.

[0018] Optionally, the detection module is also used to determine the total voltage of the power battery; in response to the difference between the sum of the voltage of the first resistor and the voltage of the second resistor and the total voltage being greater than or equal to a first voltage threshold, the voltage fluctuation of the first resistor being greater than or equal to a second voltage threshold, and the voltage fluctuation of the second resistor being greater than or equal to the second voltage threshold, an error message is reported, wherein the error message is used to indicate an error in the detection process.

[0019] According to one embodiment of the present invention, a computer-readable storage medium is also provided, wherein the storage medium stores a computer program, wherein the computer program is configured to execute the power battery capacitance detection method described above when running on a computer or processor.

[0020] According to one embodiment of the present invention, an electronic device is also provided, including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the capacitance detection method of the power battery as described above.

[0021] In this embodiment of the invention, by receiving a target control command, the conduction state of the control switch is controlled according to a preset sequence to determine the first voltage of the first resistor, the second voltage of the second resistor, the third voltage of the third resistor, and the fourth voltage of the fourth resistor. The first, second, third, and fourth resistors are located outside the power battery, which includes a target capacitor. The target capacitance value of the target capacitor is then determined based on the first, second, third, and fourth voltages and the equivalent resistance value. The equivalent resistance value is the equivalent resistance value of the first, second, fifth, and sixth resistors. The power battery also includes the fifth and sixth resistors. Finally, the target capacitor is detected based on the target capacitance value. This allows for Y-capacitor detection without requiring significant assumptions, is unrestricted, and is easy to implement. Furthermore, by repeatedly determining the voltage of each resistor based on different switch conduction states, the accuracy and cumulative deviation of each resistor are addressed. The influence of neglected wire resistance and contact resistance on the Y-capacitor result is also considered, resulting in high detection accuracy. This solves the technical problem that related technologies, which rely on significant assumptions for Y-capacitor detection of the power battery inside electric vehicles, are limited in implementation and have low detection accuracy. Attached Figure Description

[0022] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0023] Figure 1 This is a circuit diagram of a capacitance detection method for power batteries;

[0024] Figure 2 This is a circuit diagram of a power battery capacitance detection method according to one embodiment of the present invention;

[0025] Figure 3 This is a flowchart of a power battery capacitance detection method according to one embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of a Y capacitance testing system according to one embodiment of the present invention;

[0027] Figure 5 This is a structural block diagram of a power battery capacitance detection device according to one embodiment of the present invention. Detailed Implementation

[0028] For ease of understanding, some concepts related to the embodiments of the present invention are explained by way of example for reference.

[0029] As shown below:

[0030] For the Y capacitor test method of the RESS high voltage assembly inside electric vehicles: The existing power battery Y capacitor test mainly sets up a circuit including the power battery, Y capacitor, insulation resistance, balancing resistance, discharge resistance and switch. By connecting the discharge resistor to the test circuit, the voltage change characteristics of the Y capacitor are observed and recorded, and the specific value of the Y capacitor is analyzed and calculated.

[0031] Figure 1 This is a circuit diagram of a capacitance detection method for a power battery, such as... Figure 1 As shown, the specific implementation process of the above method is explained in detail. Figure 1 This includes a circuit consisting of a power battery, a Y capacitor (Cy_RESS), an insulation resistor (Riso_RESS), a balancing resistor (R_sys), a discharge resistor (R_dis), and a switch. The positive terminal of the power battery is coupled to the first terminal of the switch, the second terminal of the switch is coupled to the first terminal of the discharge resistor (R_dis), the second terminal of the discharge resistor (R_dis) is grounded, and the first terminal of the switch is coupled to the balancing resistor (R_sys). + The first end of the coupling is the balancing resistor (R_sys). + The second terminal of ) is connected to the balancing resistor (R_sys) - The first end of the coupling is the balancing resistor (R_sys). - The second end of the battery is coupled to the negative terminal of the power battery.

[0032] Figure 1 During operation, the circuit schematic in the circuit determines the voltage of the balancing resistor and the discharge resistor by controlling the conduction state of the switch. Based on the determined voltage, the voltage change characteristics of the Y capacitor are observed and recorded, and the specific value of the Y capacitor is analyzed and calculated.

[0033] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0034] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0035] According to one embodiment of the present invention, an embodiment of a method for detecting the capacitance of a power battery is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0036] This method embodiment can be executed in an electronic device, similar control device, or system that includes a memory and a processor. Taking an electronic device as an example, the electronic device may include one or more processors and a memory for storing data. Optionally, the electronic device may also include a communication device for communication functions and a display device. Those skilled in the art will understand that the above structural description is merely illustrative and does not limit the structure of the electronic device. For example, the electronic device may include more or fewer components than described above, or have a different configuration than described above.

[0037] A processor may include one or more processing units. For example, a processor may include a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processing (DSP) chip, a microcontroller unit (MCU), a field-programmable gate array (FPGA), a neural network processing unit (NPU), a tensor processing unit (TPU), or an artificial intelligence (AI) processor. Different processing units may be independent components or integrated into one or more processors. In some instances, electronic devices may also include one or more processors.

[0038] The memory can be used to store computer programs, such as the computer program corresponding to the power battery capacitance detection method in this embodiment of the invention. The processor implements the power battery capacitance detection method by running the computer program stored in the memory. The memory may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include memory remotely located relative to the processor, and these remote memories can be connected to electronic devices via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0039] Communication devices are used to receive or send data via a network. Specific examples of such networks may include wireless networks provided by the mobile terminal's communication provider. In one example, the communication device includes a network interface controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the communication device may be a radio frequency (RF) module used for wireless communication with the Internet.

[0040] The display device can be, for example, a touchscreen liquid crystal display (LCD) and a touch display (also referred to as a "touchscreen" or "touch screen"). This LCD allows the user to interact with the user interface of the mobile terminal. In some embodiments, the mobile terminal has a graphical user interface (GUI), which allows the user to interact with the GUI by touching and / or gesturing on a touch-sensitive surface. Optional human-computer interaction functions include: creating web pages, drawing, word processing, creating electronic documents, playing games, video conferencing, instant messaging, sending and receiving emails, a call interface, playing digital video, playing digital music, and / or web browsing, etc. Executable instructions for performing the above human-computer interaction functions are configured / stored in one or more processor-executable computer program products or readable storage media.

[0041] This embodiment provides a capacitance detection circuit for a power battery, including: a power battery, a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a first resistor, a second resistor, a third resistor, and a fourth resistor. The power battery includes a battery, a fifth resistor, a sixth resistor, and a target capacitor. The positive terminal of the power battery is coupled to the first terminal of the first switch. The second terminal of the first switch is coupled to the first terminal of the first resistor. The second terminal of the first resistor is coupled to the first terminal of the third switch. The second terminal of the third switch is coupled to the ground terminal of the power battery. The first terminal of the first resistor is coupled to the first terminal of the fourth switch. The second terminal of the fourth switch is coupled to the first terminal of the third resistor. The second terminal of the third resistor is coupled to the first terminal of the fourth resistor. The second terminal of the fourth resistor is coupled to the first terminal of the fifth switch. The second terminal of the fifth switch is coupled to the first terminal of the second switch. The second terminal of the second switch is coupled to the negative terminal of the power battery. The second terminal of the first resistor is coupled to the first terminal of the second resistor. The second terminal of the second resistor is coupled to the first terminal of the second switch. The first terminal of the third switch is grounded.

[0042] Figure 2 This is a circuit diagram of a power battery capacitance detection method according to one embodiment of the present invention. Figure 2 As shown, Figure 2 It includes a power battery, a first switch (S1), a second switch (S2), a third switch (S3), a fourth switch (S4), a fifth switch (S5), a first resistor (R1), a second resistor (R2), a third resistor (R3), and a fourth resistor (R4). The power battery includes a battery (DC), a fifth resistor (Riso_RESS+), a sixth resistor (Riso_RESS-), and a target capacitor (Y capacitor Cy_RESS).

[0043] The positive terminal of the power battery is coupled to the first end of S1, the second end of S1 is coupled to the first end of R1, the second end of R1 is coupled to the first end of S3, the second end of S3 is coupled to the ground terminal of the power battery, the first end of R1 is coupled to the first end of S4, the second end of S4 is coupled to the first end of R3, the second end of R3 is coupled to the first end of S3, the second end of R3 is coupled to the first end of R4, the second end of R4 is coupled to the first end of S5, the second end of S5 is coupled to the first end of S2, the second end of S2 is coupled to the negative terminal of the power battery, the second end of R1 is coupled to the first end of R2, the second end of R2 is coupled to the first end of S2, and the first end of S3 is grounded.

[0044] This embodiment provides a method for detecting the capacitance of a power battery used in an electronic device. Figure 3 This is a flowchart of a power battery capacitance detection method according to one embodiment of the present invention, such as... Figure 3 As shown, the process includes the following steps:

[0045] Step S30: Upon receiving the target control command, control the conduction state of the switches according to the preset sequence, and determine the first voltage of the first resistor, the second voltage of the second resistor, the third voltage of the third resistor, and the fourth voltage of the fourth resistor.

[0046] The first resistor, the second resistor, the third resistor, and the fourth resistor are located outside the power battery, which includes the target capacitor.

[0047] The target control command can be understood as a command used to control the conduction state of the switch. This step can be understood as receiving the command used to control the conduction state of the switch, controlling the conduction state of the switch according to a preset sequence, and determining the first voltage of the first resistor, the second voltage of the second resistor, the third voltage of the third resistor, and the fourth voltage of the fourth resistor located outside the power battery.

[0048] Optionally, this step can be implemented using the aforementioned power battery capacitance detection circuit, as described above. Figure 2 As shown, the first resistor can be understood as Figure 2 In the diagram, R1, the first voltage across the first resistor, can be understood as... Figure 2 In the context of U1, the second resistor can be understood as... Figure 2 In the diagram, R2, the second voltage across the second resistor, can be understood as... Figure 2 In the context of U2, the third resistor can be understood as... Figure 2 In the diagram, R3, the third voltage across the third resistor can be understood as U1e, and the fourth resistor can be understood as... Figure 2 In the example, R4, the fourth voltage of the fourth resistor, can be understood as U2e, but this embodiment of the invention is not limited thereto.

[0049] For example, upon receiving an instruction to control the conduction state of a switch, the conduction state of the switch is controlled according to a preset sequence, and U1, U2, U1e, and U2e located outside the power battery are determined.

[0050] It is understandable that when the circuit is dynamically changing, the voltage across the resistor will fluctuate briefly with the change in current. The first voltage of the first resistor located outside the power battery can be understood as U1 of R1 in the initial stable state of the circuit. The second voltage of the second resistor can be understood as U2 of R2 in the initial stable state of the circuit. The third voltage of the third resistor can be understood as U1e of R3 after the circuit changes. The fourth voltage of the fourth resistor can be understood as U2e of R4 after the circuit changes.

[0051] Optionally, when the target control command is to close the first switch, the second switch, and the third switch, S1, S2, and S3 are all closed, and the circuit is in an initial stable state. At this time, the first voltage U1 of the first resistor and the second voltage U2 of the second resistor are determined. Specifically, U1 and U2 can be calculated using mathematical formulas, as shown in the following formulas (1)-(2):

[0052]

[0053]

[0054] In the above formulas (1)-(2), U0 represents the total voltage of the power battery when all switches are open, and R + R represents the resistance of the positive terminal of the power battery to ground. - This represents the resistance of the negative terminal of the power battery to ground, where R... + and R - The specific expressions are shown in the following formulas (3)-(4):

[0055] R + =R iso_RESS+ / / R1 (3)

[0056] R - =R iso_RESS- / / R2 (4)

[0057] In the above formulas (3)-(4), / / indicates parallel connection.

[0058] Therefore, U1 and U2 are determined, which means determining the first voltage of the first resistor and the second voltage of the second resistor. After determining U1 and U2, the fourth and fifth switches are controlled, that is, S4 or S5 is controlled to be in the closed state. After the circuit stabilizes, the stable U1 is determined, which is the third voltage U1e of the third resistor, and the stable U2 is the fourth voltage U2e of the fourth resistor.

[0059] Step S31: Determine the target capacitance value of the target capacitor based on the first voltage, the second voltage, the third voltage, the fourth voltage, and the equivalent resistance value;

[0060] The equivalent resistance value is the equivalent resistance value of the first resistor, the second resistor, the fifth resistor, and the sixth resistor. The power battery also includes the fifth resistor and the sixth resistor.

[0061] The target capacitance value can be understood as the capacitance value inside the power battery, and the equivalent resistance is the equivalent resistance value of the first and second external resistors of the power battery, as well as the fifth and sixth internal resistors of the power battery.

[0062] This step can be understood as determining the capacitance value inside the power battery based on the first voltage, second voltage, third voltage, fourth voltage, and the equivalent resistance values ​​of the first and second external resistors of the power battery, as well as the fifth and sixth internal resistors of the power battery.

[0063] Step S32: Detect the target capacitance based on the target capacitance value.

[0064] This step can be understood as detecting the target capacitance based on the target capacitance value determined according to the first voltage, second voltage, third voltage, fourth voltage, and equivalent resistance value.

[0065] Optionally, the entire target capacitance detection process can be controlled by a host computer, and this embodiment of the invention is not limited thereto.

[0066] Figure 4 This is a schematic diagram of a Y capacitance testing system according to one embodiment of the present invention, as shown below. Figure 4 As shown, Figure 4 This includes a host computer, a 12V programmable power supply, a power battery Y-capacitor testing device, and the RESS high-voltage assembly under test. The power battery Y-capacitor testing device can be understood as... Figure 2 The circuitry outside the main power battery includes the RESS high-voltage assembly under test, which can be understood as the power battery itself. The host computer controls the entire Y-capacitor testing process, communicating with the programmable power supply and the Y-capacitor testing device via a communication interface. The 12V programmable power supply outputs energy externally, connecting to the host computer via a communication interface and to the Y-capacitor testing device via a power output interface. The Y-capacitor testing device implements the Y-capacitor testing process, connecting to the host computer, the 12V programmable power supply, and the RESS high-voltage assembly under test. The RESS high-voltage assembly under test, as the Y-capacitor being tested, is connected to the Y-capacitor testing device; a typical example is the main power battery.

[0067] Figure 4When the Y-capacitor testing system is running, the entire power battery Y-capacitor testing process is controlled by the host computer. Energy is output to the outside through a 12V programmable power supply. The power battery Y-capacitor testing device is used to realize the power battery Y-capacitor testing process. It is connected to the host computer, the 12V programmable power supply and the RESS high voltage assembly under test, respectively, to perform Y-capacitor testing on the RESS high voltage assembly under test, so as to complete the detection of the target capacitor.

[0068] Through the above steps, by receiving the target control command, controlling the conduction state of the switches according to a preset sequence, the first voltage of the first resistor, the second voltage of the second resistor, the third voltage of the third resistor, and the fourth voltage of the fourth resistor are determined. The first, second, third, and fourth resistors are located outside the power battery, which includes the target capacitor. The target capacitance value is then determined based on the first, second, third, and fourth voltages and the equivalent resistance value. The equivalent resistance value is the equivalent resistance value of the first, second, fifth, and sixth resistors. The power battery also includes the fifth and sixth resistors. Finally, the target capacitor is detected based on the target capacitance value. This allows for Y-capacitor detection without requiring significant assumptions, is unrestricted, and is easy to implement. Furthermore, by repeatedly determining the voltage of each resistor based on different switch conduction states, the accuracy and cumulative deviation of each resistor are addressed. The influence of neglected wire resistance and contact resistance on the Y-capacitor results is also considered, resulting in high detection accuracy. This solves the technical problem that related technologies for Y-capacitor detection of the power battery inside electric vehicles rely on significant assumptions, leading to method limitations, difficulty in implementation, and low detection accuracy.

[0069] Optionally, in step S31, determining the target capacitance value of the target capacitor based on the first voltage, the second voltage, the third voltage, the fourth voltage, and the equivalent resistance value may include the following steps:

[0070] Step S310: Determine the first current based on the fifth voltage and the resistance value of the third resistor, and determine the second current based on the sixth voltage and the resistance value of the fourth resistor.

[0071] Wherein, the first current is the current of the third resistor, the second current is the current of the fourth resistor, and the fifth voltage and the sixth voltage are the transient voltages of the first resistor and the second resistor, respectively.

[0072] The fifth voltage can be understood as the voltage across the first resistor at a certain moment during the change of current in the circuit. The first current can be understood as the current flowing through the third resistor at a certain moment during the change of current in the circuit. The sixth voltage can be understood as the voltage across the second resistor at a certain moment during the change of current in the circuit. The second current can be understood as the current flowing through the fourth resistor at a certain moment during the change of current in the circuit.

[0073] Optionally, this step can be implemented using the aforementioned power battery capacitance detection circuit, as described above. Figure 2 As shown, after closing the fourth switch S4, the current in the circuit changes. At a certain moment during this process, the voltage across the first resistor can be expressed as U1(t). Then, the fifth voltage U... R (t) can be expressed by a mathematical expression, as shown in the following formula (5):

[0074] U R (t)=U R1 (t)=U1(t) (5)

[0075] After closing the fourth switch S4, the current in the circuit changes. At a certain moment during this process, the voltage across the second resistor can be expressed as U2(t). Then, the sixth voltage U... R (t) can be expressed by a mathematical expression, as shown in the following formula (6):

[0076] U R (t)=U R2 (t)=U2(t) (6)

[0077] The current in the circuit changes, and the current flowing through the first resistor at a certain moment in this process can be expressed as I1(t). I1(t) can be expressed by a mathematical expression, as shown in the following formula (7):

[0078] I1(t)=(U R1 (t)) / (R1)=U1(t) / R1 (7)

[0079] The current in the circuit changes, and the current flowing through the first resistor at a certain moment in this process can be expressed as I2(t). I2(t) can be expressed by a mathematical expression, as shown in the following formula (8):

[0080] I2(t)=(U R2 (t)) / (R2)=U2(t) / R2 (8)

[0081] Then, after closing the fourth switch S4, the first current I(t) flowing through the third resistor at a certain moment during the change of current in the circuit can be expressed by a mathematical expression, as shown in the following formula (9):

[0082] I(t)=U R1 / R3 (9)

[0083] Then, after closing the fifth switch S5, the second current I(t) flowing through the fourth resistor at a certain moment during the change of current in the circuit can be expressed by a mathematical expression, as shown in the following formula (10):

[0084] I(t)=U R2 / R4 (10)

[0085] The first current and the second current are thus determined, and the embodiments of the present invention are not limited thereto.

[0086] Step S311: Perform a first deformation process on the first current based on the equivalent resistance value to determine the first target current; and perform a second deformation process on the second current based on the equivalent resistance value to determine the second target current.

[0087] The first target current can be understood as the first current expressed in terms of equivalent resistance, and the second target current can be understood as the second current expressed in terms of equivalent resistance.

[0088] Optionally, this step can be implemented using the aforementioned power battery capacitance detection circuit, as described above. Figure 2 As shown, after closing the fourth switch S4, the first current flowing through the first resistor at a certain moment during the change of current in the circuit is determined, and the equivalent resistance value is expressed as R. i Then the first target current can be expressed by a mathematical expression, as shown in the following formula (11):

[0089] I(t) = C y U1(t)e -t / RCy =C y U1e -t / (R3+Ri)Cy (11)

[0090] As mentioned above Figure 2 As shown, after closing the fourth switch S5, and determining the second current flowing through the second resistor at a certain moment during the change of current in the circuit, the equivalent resistance value is expressed as R. i Then the second target current can be expressed by a mathematical expression, as shown in the following formula (12):

[0091] I(t) = C y U2(t)e -t / RCy =C y U1e -t / (R4+Ri)Cy (12)

[0092] In the above formulas (11)-(12), C y The voltage across the capacitor Cy_RESS+ represents the voltage across the capacitor at a given moment when the current in the circuit changes. This voltage can be expressed mathematically as shown in the following formula (13):

[0093] U cy_RESS+ (t)=Us(1-e -t / RC )=U1(1-e -t / RC (13)

[0094] The voltage across capacitor Cy_RESS at a certain moment can be expressed by a mathematical expression, as shown in the following formula (14):

[0095] U cy_RESS- (t)=Us(1-e -t / RC )=U2(1-e -t / RC (14)

[0096] The charging current of capacitor Cy_RESS+ at a certain moment can be expressed by a mathematical expression, as shown in the following formula (15):

[0097] I1(t)=C y (du) / (dt)=C y U1d(1-e -t / RC ) / dt=C y U1e -t / RCy (15)

[0098] The charging current of the capacitor Cy_RESS at a certain moment can be expressed by a mathematical expression, as shown in the following formula (16):

[0099] I2(t)=C y (du) / (dt)=C y U2d(1-e -t / RC ) / dt=C y U2e -t / RCy (16)

[0100] The first target current and the second target current are thus determined, and the embodiments of the present invention are not limited thereto.

[0101] Step S312: Process the first target current based on the first voltage and the third voltage to determine the first target voltage; and process the second target current based on the second voltage and the fourth voltage to determine the second target voltage.

[0102] Optionally, this step can be implemented using the aforementioned power battery capacitance detection circuit, as described above. Figure 2 As shown, after closing the fourth switch S4, the first current flowing through the first resistor at a certain moment during the change of current in the circuit is determined, and the equivalent resistance value is expressed as R. i Then the first target current U1(t2) can be expressed by a mathematical expression, as shown in the following formula (17):

[0103] U1(t2)=(U1(t1)-U 1e )e t / (R3+Ri)Cy +U 1e (17)

[0104] The second target current U2(t2') can be expressed by a mathematical expression, as shown in the following formula (18):

[0105] U2(t2')=(U2(t1')-U 2e )e t / (R4+Ri)Cy +U 2e (18)

[0106] The first target voltage and the second target voltage are thus determined, and the embodiments of the present invention are not limited thereto.

[0107] Step S313: Determine the target capacitance value based on the first target voltage and the second target voltage.

[0108] After determining the first target voltage and the second target voltage, the target capacitance value is determined based on the first target voltage and the second target voltage.

[0109] Alternatively, the target capacitance value Cy can be determined by mathematical formula, as shown in the following formula (19):

[0110] Cy=((t2-t1) / (Cyln((U1(t2)-U 1e ) / (U1(t1)-U 1e )))

[0111] -(t2'-t1') / (ln((U2(t2')-U 2e ) /

[0112] (U2(t1')-U 2e )))) / (R3-R4) (19)

[0113] The target capacitance value is thus determined, and the embodiments of the present invention are not limited thereto.

[0114] Optionally, in step S312, processing the first target current based on the first voltage and the third voltage to determine the first target voltage, and processing the second target current based on the second voltage and the fourth voltage to determine the second target voltage may include the following execution steps:

[0115] Step S3120: Perform a third deformation process on the first current based on the first voltage and the third voltage to obtain a first initial voltage; and perform a fourth deformation process on the second current based on the second voltage and the fourth voltage to obtain a second initial voltage.

[0116] The first initial voltage can be understood as the voltage across the first resistor at a certain moment after a change in current in the circuit, and the second initial voltage can be understood as the voltage across the second resistor at a certain moment after a change in current in the circuit.

[0117] Optionally, this step can be implemented using the aforementioned power battery capacitance detection circuit, as described above. Figure 2 As shown, after closing the fourth switch S4, the current in the circuit changes, and the first initial voltage U1(t) can be expressed by a mathematical expression, as shown in the following formula (20):

[0118] U1(t)=(U1-U 1e )e t(R3+Ri)Cy +U 1e (20)

[0119] After closing the fifth switch S5, the current in the circuit changes, and the second initial voltage U2(t) can be expressed by a mathematical expression, as shown in the following formula (21):

[0120] U2(t2)=(U2-U 2e )e t / (R4+Ri)Cy +U 2e (twenty one)

[0121] The first initial voltage and the second initial voltage are thus determined, and the embodiments of the present invention are not limited thereto.

[0122] Step S3121: Based on the first moment, perform a fifth deformation process on the first initial voltage to obtain the first target voltage, and based on the second moment, perform a sixth deformation process on the second initial voltage to obtain the second target voltage.

[0123] The first and second moments are outside the preset time period following the initial moment.

[0124] It is understandable that when determining each voltage, the selected time point has a functional relationship with the accuracy of the determined voltage. The earlier the time point, the steeper the slope, which may lead to circuit instability and lower voltage accuracy. Therefore, a value at a later time point is selected, where the slope is smaller, the circuit is more stable, and the voltage accuracy is higher.

[0125] The initial moment can be understood as the starting moment for detecting the capacitance of the power battery. The preset time period is used to ensure that the voltage determined at the selected time point is highly accurate. That is, when the voltage is determined at a time point outside the preset time period after the initial moment, the circuit is more stable and the determined voltage is more accurate.

[0126] Optionally, in step S313, determining the target capacitance value based on the first target voltage and the second target voltage may include the following steps:

[0127] Step S3130: The equivalent resistance value is canceled out based on the first target voltage and the second target voltage to obtain the target capacitance value.

[0128] This step can be understood as the specific calculation process of the above formula (19), which will not be elaborated here.

[0129] Optionally, in step S31, the target control command includes a first control command, a second control command, and a third control command. Receiving the target control command and controlling the conduction state of the switches according to a preset sequence, determining the first voltage of the first resistor, the second voltage of the second resistor, the third voltage of the third resistor, and the fourth voltage of the fourth resistor may include the following execution steps:

[0130] Step S314: Upon receiving the first control command, determine the first voltage of the first resistor and the second voltage of the second resistor;

[0131] The first control command is used to control the first switch, the second switch, and the third switch to all be turned on.

[0132] Optionally, this step can be implemented using the aforementioned power battery capacitance detection circuit, as described above. Figure 2 As shown, the first control command can be understood as a command to control the first switch S1, the second switch S2 and the third switch S3 to be turned on. After receiving the first control command, S1, S2 and S3 are closed, and step 30 is executed to determine the first voltage of the first resistor and the second voltage of the second resistor. This embodiment of the invention is not limited.

[0133] Step S315: Receive the second control command and determine the third voltage of the third resistor;

[0134] The second control command is used to control the first switch, the second switch, the third switch and the fourth switch to be turned on, and the fourth switch is used to control the third resistor to be connected in parallel with the first resistor.

[0135] Optionally, this step can be implemented using the aforementioned power battery capacitance detection circuit, as described above. Figure 2 As shown, the second control command can be understood as a command to control the first switch S1, the second switch S2, the third switch S3 and the fourth switch S4 to be turned on. After receiving the first control command, S1, S2, S3 and S4 are closed, and step 30 is executed to determine the third voltage of the third resistor. This embodiment of the invention is not limited.

[0136] Step S316: Receive the third control command and determine the fourth voltage of the fourth resistor.

[0137] The second control command is used to control the first switch, the second switch, the third switch and the fifth switch to be turned on, and the fifth switch is used to control the fourth resistor to be connected in parallel with the second resistor.

[0138] Optionally, this step can be implemented using the aforementioned power battery capacitance detection circuit, as described above. Figure 2 As shown, the second control command can be understood as a command to control the first switch S1, the second switch S2, the third switch S3 and the fifth switch S5 to be turned on. After receiving the first control command, S1, S2, S3 and S5 are closed, and step 30 is executed to determine the fourth voltage of the fourth resistor. This embodiment of the invention is not limited.

[0139] Optionally, in step S32, the method may further include the following execution steps:

[0140] Step S320: Determine the total voltage of the power battery;

[0141] Optionally, this step can be implemented using the aforementioned power battery capacitance detection circuit, as described above. Figure 2 As shown, the total voltage of the power battery is the total voltage U0 of the power battery when all switches are off. This step can be understood as continuously detecting the total voltage U0 of the power battery to determine the total voltage of the power battery. This embodiment of the invention does not limit this.

[0142] In step S321, in response to the fact that the difference between the sum of the voltages of the first resistor and the second resistor and the total voltage is greater than or equal to a first voltage threshold, the voltage fluctuation of the first resistor is greater than or equal to a second voltage threshold, and the voltage fluctuation of the second resistor is greater than or equal to a second voltage threshold, an error message is reported.

[0143] Error messages are used to indicate errors in the detection process.

[0144] The first voltage threshold can be understood as the maximum error between the sum of the voltages of the first resistor and the second resistor and the total voltage. That is, when the difference between the sum of the voltages of the first resistor and the second resistor and the total voltage is greater than or equal to the first voltage threshold, it indicates that the sum of the voltages of the first resistor and the second resistor is greater than or equal to the total voltage, and there is an abnormality in the circuit.

[0145] The second voltage threshold can be understood as the maximum value of the allowable error range of voltage fluctuations. That is, when the voltage fluctuation of the first resistor is greater than or equal to the second voltage threshold and the voltage fluctuation of the second resistor is greater than or equal to the second voltage threshold, it indicates that the voltage fluctuations of the first resistor and the second resistor are large, affecting the normal detection process.

[0146] This step can be understood as follows: when the difference between the voltage of the first resistor and the sum of the voltages of the second resistor and the total voltage is greater than or equal to the first voltage threshold, and the voltage fluctuation of the first resistor is greater than or equal to the second voltage threshold, and the voltage fluctuation of the second resistor is greater than or equal to the second voltage threshold, it indicates that the voltage of the first resistor and the sum of the voltages of the second resistor are greater than or equal to the total voltage, the circuit is abnormal, and the voltage fluctuation of the first resistor and the second resistor is large, affecting the normal detection process. At this time, an error message indicating an error in the detection process is reported.

[0147] In an optional embodiment, steps S320 to S321 can be performed each time the current in the circuit changes. Exemplarily, this step can be implemented using the capacitance detection circuit of the power battery, as described above. Figure 2 As shown, S1 is in the high-voltage positive circuit, S2 is in the high-voltage negative circuit, and S3 is in the outer casing ground circuit. It can be understood that, considering the need to ensure safety, preferably, S3 can be closed first to check the state of switch S3, then S2 can be closed to check the state of switch S2, and finally S31 can be closed to check the state of switch S1. The above steps S320 to S321 are performed to detect the circuit each time the circuit changes. This embodiment of the invention does not limit the scope of the invention.

[0148] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0149] This embodiment also provides a capacitance detection device for a power battery, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0150] Figure 5 This is a structural block diagram of a power battery capacitance detection device according to one embodiment of the present invention, such as... Figure 5As shown, taking a power battery capacitance detection device 500 as an example, the device includes: a control module 501, which receives a target control command, controls the conduction state of switches according to a preset sequence, and determines the first voltage of a first resistor, the second voltage of a second resistor, the third voltage of a third resistor, and the fourth voltage of a fourth resistor, wherein the first, second, third, and fourth resistors are located outside the power battery, and the power battery includes a target capacitor; a determination module 502, which determines the target capacitance value of the target capacitor based on the first voltage, the second voltage, the third voltage, the fourth voltage, and the equivalent resistance value, wherein the equivalent resistance value is the equivalent resistance value of the first, second, fifth, and sixth resistors, and the power battery also includes the fifth and sixth resistors; and a detection module 503, which detects the target capacitor based on the target capacitance value.

[0151] Optionally, the determining module 502 is further configured to determine a first current based on a fifth voltage and the resistance value of a third resistor, and to determine a second current based on a sixth voltage and the resistance value of a fourth resistor, wherein the first current is the current of the third resistor, the second current is the current of the fourth resistor, and the fifth voltage and the sixth voltage are the transient voltages of the first resistor and the second resistor, respectively; to perform a first deformation processing on the first current based on the equivalent resistance value to determine a first target current, and to perform a second deformation processing on the second current based on the equivalent resistance value to determine a second target current; to process the first target current based on the first voltage and the third voltage to determine a first target voltage, and to process the second target current based on the second voltage and the fourth voltage to determine a second target voltage; and to determine a target capacitance value based on the first target voltage and the second target voltage.

[0152] Optionally, the determining module 502 is further configured to perform a third deformation process on the first current based on the first voltage and the third voltage to obtain a first initial voltage, and perform a fourth deformation process on the second current based on the second voltage and the fourth voltage to obtain a second initial voltage; perform a fifth deformation process on the first initial voltage based on a first moment to obtain a first target voltage, and perform a sixth deformation process on the second initial voltage based on a second moment to obtain a second target voltage, wherein the first moment and the second moment are outside a preset time period after the initial moment.

[0153] Optionally, the determining module 502 is further configured to perform cancellation processing on the equivalent resistance value based on the first target voltage and the second target voltage to obtain the target capacitance value.

[0154] Optionally, the determining module 502 is further configured to receive a first control instruction and determine a first voltage of the first resistor and a second voltage of the second resistor, wherein the first control instruction is used to control the first switch, the second switch, and the third switch to all be turned on; receive a second control instruction and determine a third voltage of the third resistor, wherein the second control instruction is used to control the first switch, the second switch, the third switch, and the fourth switch to all be turned on, and the fourth switch is used to control the third resistor to be connected in parallel with the first resistor; receive a third control instruction and determine a fourth voltage of the fourth resistor, wherein the second control instruction is used to control the first switch, the second switch, the third switch, and the fifth switch to all be turned on, and the fifth switch is used to control the fourth resistor to be connected in parallel with the second resistor.

[0155] Optionally, the detection module 503 is further configured to determine the total voltage of the power battery; in response to the difference between the sum of the voltages of the first resistor and the voltages of the second resistor and the total voltage being greater than or equal to a first voltage threshold, the voltage fluctuation of the first resistor being greater than or equal to a second voltage threshold, and the voltage fluctuation of the second resistor being greater than or equal to the second voltage threshold, an error message is reported, wherein the error message is used to indicate an error in the detection process.

[0156] It should be noted that the above modules can be implemented by software or hardware. For the latter, they can be implemented in the following ways, but are not limited to: all the above modules are located in the same processor; or, the above modules are located in different processors in any combination.

[0157] Embodiments of the present invention also provide a computer-readable storage medium storing a computer program, wherein the computer program is configured to perform the steps in any of the above method embodiments when run on a computer or processor.

[0158] Optionally, in this embodiment, the computer-readable storage medium may be configured to store a computer program for performing the following steps:

[0159] Step S1: Upon receiving the target control command, control the conduction state of the switches according to the preset sequence, and determine the first voltage of the first resistor, the second voltage of the second resistor, the third voltage of the third resistor, and the fourth voltage of the fourth resistor.

[0160] Step S2: Determine the target capacitance value of the target capacitor based on the first voltage, the second voltage, the third voltage, the fourth voltage, and the equivalent resistance value;

[0161] Step S3: Detect the target capacitance based on the target capacitance value.

[0162] Optionally, in this embodiment, the computer-readable storage medium may include, but is not limited to, various media capable of storing computer programs, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0163] Embodiments of the present invention also provide an electronic device including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the steps in any of the above method embodiments.

[0164] Optionally, in this embodiment, the processor in the above-described electronic device may be configured to run a computer program to perform the following steps:

[0165] Step S1: Upon receiving the target control command, control the conduction state of the switches according to the preset sequence, and determine the first voltage of the first resistor, the second voltage of the second resistor, the third voltage of the third resistor, and the fourth voltage of the fourth resistor.

[0166] Step S2: Determine the target capacitance value of the target capacitor based on the first voltage, the second voltage, the third voltage, the fourth voltage, and the equivalent resistance value;

[0167] Step S3: Detect the target capacitance based on the target capacitance value.

[0168] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementations, and will not be repeated here.

[0169] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0170] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0171] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0172] 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 units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0173] Furthermore, the functional units in the various embodiments of the present invention 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. The integrated unit can be implemented in hardware or as a software functional unit.

[0174] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part 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 the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0175] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for detecting the capacitance of a power battery, characterized in that, include: Upon receiving a target control command, the system controls the conduction state of the switches according to a preset sequence, and determines the first voltage of the first resistor, the second voltage of the second resistor, the third voltage of the third resistor, and the fourth voltage of the fourth resistor. The first resistor, the second resistor, the third resistor, and the fourth resistor are located outside the power battery, and the power battery includes a target capacitor. The target capacitance value of the target capacitor is determined based on the first voltage, the second voltage, the third voltage, the fourth voltage, and the equivalent resistance value, wherein the equivalent resistance value is the resistance value of the equivalent resistance of the first resistor, the second resistor, the fifth resistor, and the sixth resistor, and wherein the power battery further includes the fifth resistor and the sixth resistor; The target capacitance is detected based on the target capacitance value; The step of determining the target capacitance value of the target capacitor based on the first voltage, the second voltage, the third voltage, the fourth voltage, and the equivalent resistance value includes: determining a first current based on a fifth voltage and the resistance value of the third resistor, and determining a second current based on a sixth voltage and the resistance value of the fourth resistor, wherein the first current is the current of the third resistor, the second current is the current of the fourth resistor, and the fifth voltage and the sixth voltage are the transient voltages of the first resistor and the second resistor, respectively; performing a first deformation process on the first current based on the equivalent resistance value to determine a first target current, and performing a second deformation process on the second current based on the equivalent resistance value to determine a second target current; processing the first target current based on the first voltage and the third voltage to determine a first target voltage, and processing the second target current based on the second voltage and the fourth voltage to determine a second target voltage; and determining the target capacitance value based on the first target voltage and the second target voltage.

2. The method according to claim 1, characterized in that, The process of processing the first target current based on the first voltage and the third voltage to determine the first target voltage, and processing the second target current based on the second voltage and the fourth voltage to determine the second target voltage, includes: The first current is subjected to a third deformation process based on the first voltage and the third voltage to obtain a first initial voltage, and the second current is subjected to a fourth deformation process based on the second voltage and the fourth voltage to obtain a second initial voltage; The first target voltage is obtained by performing a fifth deformation process on the first initial voltage based on a first time point, and the second target voltage is obtained by performing a sixth deformation process on the second initial voltage based on a second time point, wherein the first time point and the second time point are outside a preset time period after the initial time point.

3. The method according to claim 1, characterized in that, Determining the target capacitance value based on the first target voltage and the second target voltage includes: The equivalent resistance value is canceled out based on the first target voltage and the second target voltage to obtain the target capacitance value.

4. The method according to claim 1, characterized in that, The target control command includes a first control command, a second control command, and a third control command. Upon receiving the target control command, determining the conduction state of the switches according to a preset sequence, and determining the first voltage of the first resistor, the second voltage of the second resistor, the third voltage of the third resistor, and the fourth voltage of the fourth resistor, includes: Upon receiving the first control command, the first voltage of the first resistor and the second voltage of the second resistor are determined, wherein the first control command is used to control the first switch, the second switch and the third switch to be turned on. Upon receiving the second control command, the third voltage of the third resistor is determined, wherein the second control command is used to control the first switch, the second switch, the third switch and the fourth switch to be turned on, and the fourth switch is used to control the third resistor to be connected in parallel with the first resistor; Upon receiving the third control command, the fourth voltage of the fourth resistor is determined, wherein the second control command is used to control the first switch, the second switch, the third switch and the fifth switch to all be turned on, and the fifth switch is used to control the fourth resistor to be connected in parallel with the second resistor.

5. The method according to any one of claims 1-4, characterized in that, Also includes: Determine the total voltage of the power battery; In response to the fact that the difference between the sum of the voltages of the first resistor and the second resistor and the total voltage is greater than or equal to a first voltage threshold, the voltage fluctuation of the first resistor is greater than or equal to a second voltage threshold, and the voltage fluctuation of the second resistor is greater than or equal to the second voltage threshold, an error message is reported, wherein the error message is used to indicate an error in the detection process.

6. A capacitance detection circuit for a power battery, characterized in that, The capacitance detection circuit for performing the power battery capacitance detection method according to any one of claims 1 to 5 comprises: a power battery, a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a first resistor, a second resistor, a third resistor, and a fourth resistor; the power battery comprises a battery, a fifth resistor, a sixth resistor, and a target capacitor. The positive terminal of the power battery is coupled to the first terminal of the first switch, the second terminal of the first switch is coupled to the first terminal of the first resistor, the second terminal of the first resistor is coupled to the first terminal of the third switch, and the second terminal of the third switch is coupled to the ground terminal of the power battery. The first terminal of the first resistor is coupled to the first terminal of the fourth switch, the second terminal of the fourth switch is coupled to the first terminal of the third resistor, and the second terminal of the third resistor is coupled to the first terminal of the third switch. The second end of the third resistor is coupled to the first end of the fourth resistor, the second end of the fourth resistor is coupled to the first end of the fifth switch, the second end of the fifth switch is coupled to the first end of the second switch, and the second end of the second switch is coupled to the negative terminal of the power battery. The second end of the first resistor is coupled to the first end of the second resistor, the second end of the second resistor is coupled to the first end of the second switch, and the first end of the third switch is grounded.

7. A capacitance detection device for a power battery, characterized in that, include: The control module is used to receive a target control command, control the conduction state of the switches according to a preset sequence, and determine the first voltage of the first resistor, the second voltage of the second resistor, the third voltage of the third resistor, and the fourth voltage of the fourth resistor. The first resistor, the second resistor, the third resistor, and the fourth resistor are located outside the power battery, and the power battery includes a target capacitor. The determining module is used to determine the target capacitance value of the target capacitor based on the first voltage, the second voltage, the third voltage, the fourth voltage, and the equivalent resistance value, wherein the equivalent resistance value is the resistance value of the equivalent resistance of the first resistor, the second resistor, the fifth resistor, and the sixth resistor, and wherein the power battery further includes the fifth resistor and the sixth resistor; A detection module, wherein the detection module is used to detect the target capacitance based on the target capacitance value; The determining module is further configured to: determine a first current based on a fifth voltage and the resistance value of the third resistor; and determine a second current based on a sixth voltage and the resistance value of the fourth resistor, wherein the first current is the current of the third resistor, the second current is the current of the fourth resistor, and the fifth voltage and the sixth voltage are transient voltages of the first resistor and the second resistor, respectively; perform a first deformation processing on the first current based on the equivalent resistance value to determine a first target current; and perform a second deformation processing on the second current based on the equivalent resistance value to determine a second target current; process the first target current based on the first voltage and the third voltage to determine a first target voltage; and process the second target current based on the second voltage and the fourth voltage to determine a second target voltage; and determine the target capacitance value based on the first target voltage and the second target voltage.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, wherein the computer program is configured to execute the capacitance detection method for a power battery as described in any one of claims 1 to 5 when run on a computer or processor.

9. An electronic device comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to run the computer program to perform the capacitance detection method for the power battery as described in any one of claims 1 to 5.

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