Functional safety testing methods, devices and vehicles for power batteries

Abstract

This invention discloses a method, apparatus, and vehicle for functional safety testing of power batteries. The method includes: acquiring a first current signal, a second current signal, a voltage signal, and a temperature signal corresponding to the power battery, wherein the first current signal is a digital signal and the second current signal is an analog signal; performing sensor fault diagnosis and overcurrent detection based on the first and second current signals to obtain a first detection result; performing rationality testing and overcurrent detection based on the voltage signal, temperature signal, and the opening / closing state of the power battery's contactor to obtain a second detection result; and determining a target overcurrent detection result corresponding to the power battery based on the first and second detection results. This invention solves the technical problem of low accuracy and poor safety in existing functional safety testing methods for power batteries that rely solely on current sensors for overcurrent detection.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicles, and more specifically, to a method, apparatus, and vehicle for testing the functional safety of power batteries. Background Technology

[0002] In recent years, new energy vehicles have flourished. Power batteries are the core component of new energy vehicles, and their safety and reliability directly affect driving safety and lifespan. Therefore, the development of functional safety features for power battery management systems is widely underway. During the development of functional safety features for power battery management systems, to ensure the reliability of current sampling signals, dual current sensors are typically used for redundant current measurement and fault diagnosis (such as whether the temperature is out of range or whether the sampling is out of range).

[0003] However, due to the high safety requirements for current detection functions, existing functional safety testing methods for power batteries only use dual current sensors for current detection. When there are errors in the current signals collected by the dual current sensors, the accuracy of overcurrent detection results is easily poor. Alternatively, when both current sensors are faulty, overcurrent detection of the power battery cannot be performed, resulting in poor safety of overcurrent detection and failure to meet the functional safety requirements of current detection.

[0004] There is currently no effective solution to the problem that existing functional safety testing methods for power batteries rely solely on current sensors for overcurrent detection, resulting in low accuracy and poor safety. Summary of the Invention

[0005] This invention provides a method, apparatus, and vehicle for functional safety testing of power batteries, which at least solves the technical problem that existing functional safety testing methods for power batteries rely solely on current sensors for overcurrent detection, resulting in low accuracy and poor safety.

[0006] According to one aspect of the present invention, a method for functional safety testing of a power battery is provided, comprising:

[0007] The system acquires a first current signal, a second current signal, a voltage signal, and a temperature signal corresponding to the power battery, wherein the first current signal is a digital signal and the second current signal is an analog signal; it performs sensor fault diagnosis and overcurrent detection based on the first and second current signals to obtain a first detection result; it performs rationality detection and overcurrent detection based on the voltage signal, temperature signal, and the opening and closing state of the power battery contactor to obtain a second detection result; and it determines a target overcurrent detection result corresponding to the power battery based on the first and second detection results, wherein the target overcurrent detection result is used to assist in the functional safety testing of the power battery.

[0008] Optionally, acquiring the first current signal and the second current signal corresponding to the power battery includes: controlling the first sensor to collect current data to generate the first current signal, and controlling the second sensor to collect current data to generate the second current signal, wherein the first sensor and the second sensor are connected to the power battery.

[0009] Optionally, the sensor fault diagnosis and overcurrent detection based on the first current signal and the second current signal to obtain the first detection result includes: determining the allowable current value of the power battery under the current operating condition according to the charge and discharge state parameters of the power battery, wherein the charge and discharge state parameters include: charge and discharge mode, current temperature, current voltage and current charge; performing fault diagnosis on the first sensor and the second sensor to obtain the diagnosis result; and performing overcurrent detection on the power battery based on the first current signal, the second current signal, the allowable current value and the diagnosis result to obtain the first detection result.

[0010] Optionally, overcurrent detection of the power battery is performed based on the first current signal, the second current signal, the allowable current value, and the diagnostic result to obtain the first detection result, including: in response to the fault diagnosis that the first sensor is not faulty and the second sensor is faulty, determining the first current value as the target current value, wherein the first current value is the current current value corresponding to the first current signal; in response to the fault diagnosis that the first sensor is faulty and the second sensor is not faulty, determining the second current value as the target current value, wherein the second current value is the current current value corresponding to the second current signal; in response to the fault diagnosis that neither the first nor the second sensor is faulty, and the difference between the first current value and the second current value is less than a preset error threshold, performing a weighted calculation on the first current value and the second current value to obtain the target current value; in response to the target current value exceeding the allowable current value, determining the first detection result as indicating that the power battery has an overcurrent fault.

[0011] Optionally, the rationality detection and overcurrent detection based on the voltage signal, temperature signal and the opening and closing state of the contactor of the power battery are performed to obtain the second detection result, including: performing rationality detection on the voltage signal, temperature signal and the opening and closing state of the contactor of the power battery to obtain the third detection result; in response to the third detection result meeting the preset vehicle safety integrity level conditions, performing overcurrent detection based on the voltage signal and temperature signal to obtain the second detection result.

[0012] Optionally, the rationality of the voltage signal, temperature signal, and the opening and closing state of the power battery contactor is tested to obtain a third test result, including: testing the range rationality of the voltage signal and temperature signal to obtain a fourth test result; testing the disconnection rationality of the opening and closing state of the power battery contactor to obtain a fifth test result; and determining that the third test result meets the preset vehicle safety integrity level conditions if both the fourth and fifth test results meet the preset vehicle safety integrity level conditions.

[0013] Optionally, in response to the third detection result satisfying the preset vehicle safety integrity level condition, overcurrent detection is performed based on voltage and temperature signals to obtain a second detection result, including: using a voltage safety mechanism to perform overcurrent detection on the voltage signal to obtain a sixth detection result, wherein the voltage safety mechanism is used to determine whether the power battery has experienced an overcurrent fault according to the overcurrent voltage change rule of the power battery; using a temperature safety mechanism to perform overcurrent detection on the temperature signal to obtain a seventh detection result, wherein the temperature safety mechanism is used to determine whether the power battery has experienced an overcurrent fault according to the overcurrent temperature change rule of the power battery; in response to at least one of the sixth and seventh detection results being an overcurrent fault in the power battery, the second detection result is determined to be an overcurrent fault in the power battery.

[0014] Optionally, determining the target overcurrent detection result corresponding to the power battery based on the first detection result and the second detection result includes: in response to at least one of the first detection result and the second detection result indicating that the power battery has an overcurrent fault, determining the target overcurrent detection result as indicating that the power battery has an overcurrent fault.

[0015] According to another aspect of the present invention, an overcurrent detection device for a power battery is also provided, comprising:

[0016] The acquisition module is used to acquire a first current signal, a second current signal, a voltage signal, and a temperature signal corresponding to the power battery, wherein the first current signal is a digital signal and the second current signal is an analog signal; the first detection module is used to perform sensor fault diagnosis and overcurrent detection based on the first current signal and the second current signal to obtain a first detection result; the second detection module is used to perform rationality detection and overcurrent detection based on the voltage signal, temperature signal, and the opening and closing state of the power battery contactor to obtain a second detection result; the determination module is used to determine the target overcurrent detection result corresponding to the power battery based on the first detection result and the second detection result, wherein the target overcurrent detection result is used to assist in the functional safety testing of the power battery.

[0017] Optionally, the acquisition module is further configured to: acquire the first current signal and the second current signal corresponding to the power battery, including: controlling the first sensor to collect current data to generate the first current signal, and controlling the second sensor to collect current data to generate the second current signal, wherein the first sensor and the second sensor are connected to the power battery.

[0018] Optionally, the first detection module is further configured to: perform sensor fault diagnosis and overcurrent detection based on the first current signal and the second current signal to obtain a first detection result, including: determining the allowable current value of the power battery under the current operating condition according to the charge and discharge state parameters of the power battery, wherein the charge and discharge state parameters include: charge and discharge mode, current temperature, current voltage and current charge; performing fault diagnosis on the first sensor and the second sensor to obtain a diagnosis result; and performing overcurrent detection on the power battery based on the first current signal, the second current signal, the allowable current value and the diagnosis result to obtain a first detection result.

[0019] Optionally, the first detection module is further configured to: perform overcurrent detection on the power battery based on the first current signal, the second current signal, the allowable current value, and the diagnostic result, and obtain a first detection result including: in response to a fault diagnosis that the first sensor is not faulty and the second sensor is faulty, determining the first current value as the target current value, wherein the first current value is the current current value corresponding to the first current signal; in response to a fault diagnosis that the first sensor is faulty and the second sensor is not faulty, determining the second current value as the target current value, wherein the second current value is the current current value corresponding to the second current signal; in response to a fault diagnosis that neither the first nor the second sensor is faulty, and the difference between the first current value and the second current value is less than a preset error threshold, performing a weighted calculation on the first current value and the second current value to obtain the target current value; in response to the target current value exceeding the allowable current value, determining that the first detection result indicates an overcurrent fault in the power battery.

[0020] Optionally, the second detection module is further configured to: perform rationality detection and overcurrent detection based on voltage signals, temperature signals, and the opening and closing states of the contactor of the power battery, and obtain a second detection result including: performing rationality detection on voltage signals, temperature signals, and the opening and closing states of the contactor of the power battery to obtain a third detection result; and, in response to the third detection result satisfying the preset vehicle safety integrity level conditions, performing overcurrent detection based on voltage signals and temperature signals to obtain a second detection result.

[0021] Optionally, the second detection module is further configured to: perform reasonableness detection on the voltage signal, temperature signal, and the opening / closing state of the power battery contactor to obtain a third detection result, including: performing range reasonableness detection on the voltage signal and temperature signal to obtain a fourth detection result; performing disconnection reasonableness detection on the opening / closing state of the power battery contactor to obtain a fifth detection result; and determining that the third detection result meets the preset vehicle safety integrity level conditions if both the fourth and fifth detection results satisfy the preset vehicle safety integrity level conditions.

[0022] Optionally, the second detection module is further configured to: in response to the third detection result satisfying the preset vehicle safety integrity level condition, perform overcurrent detection based on voltage and temperature signals to obtain a second detection result, including: using a voltage safety mechanism to perform overcurrent detection on the voltage signal to obtain a sixth detection result, wherein the voltage safety mechanism is used to determine whether the power battery has experienced an overcurrent fault according to the overcurrent voltage change rule of the power battery; using a temperature safety mechanism to perform overcurrent detection on the temperature signal to obtain a seventh detection result, wherein the temperature safety mechanism is used to determine whether the power battery has experienced an overcurrent fault according to the overcurrent temperature change rule of the power battery; in response to at least one of the sixth and seventh detection results being an overcurrent fault in the power battery, determine the second detection result as an overcurrent fault in the power battery.

[0023] Optionally, the above-mentioned determining module is further configured to: determine the target overcurrent detection result corresponding to the power battery based on the first detection result and the second detection result, including: in response to at least one of the first detection result and the second detection result being an overcurrent fault in the power battery, determine the target overcurrent detection result as an overcurrent fault in the power battery.

[0024] According to another aspect of the present invention, a vehicle is also provided, including an on-board memory and an on-board processor, characterized in that the on-board memory stores a computer program, and the on-board processor is configured to run the computer program to execute the power battery functional safety testing method described in any of the preceding embodiments.

[0025] In this embodiment of the invention, firstly, a first current signal, a second current signal, a voltage signal, and a temperature signal corresponding to the power battery are acquired, wherein the first current signal is a digital signal and the second current signal is an analog signal. Then, sensor fault diagnosis and overcurrent detection are performed based on the first current signal and the second current signal to obtain a first detection result. Next, rationality detection and overcurrent detection are performed based on the voltage signal, the temperature signal, and the opening and closing state of the power battery contactor to obtain a second detection result. Finally, based on the first detection result and the second detection result, a target overcurrent detection result corresponding to the power battery is determined, wherein the target overcurrent detection result is used to assist in the functional safety testing of the power battery.

[0026] As is easily understood, this invention improves the accuracy and safety of overcurrent detection by performing rationality and overcurrent detection on the first and second current signals, voltage signals, temperature signals, and the opening and closing state of the contactor obtained by dual current sensors. This achieves the technical effect of combining voltage signals, temperature signals, and the opening and closing state of the contactor to perform overcurrent detection on the power battery, thereby improving the accuracy and safety of overcurrent detection. Furthermore, it solves the technical problem of low accuracy and poor safety in existing functional safety testing methods for power batteries that rely solely on current sensors for overcurrent detection. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0028] Figure 1 This is a hardware structure block diagram of a vehicle terminal for an optional overcurrent detection method for a power battery according to an embodiment of the present invention.

[0029] Figure 2 This is a flowchart of an overcurrent detection method for a power battery according to an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of an optional overcurrent detection process for a power battery according to an embodiment of the present invention;

[0031] Figure 4 This is a flowchart of an optional overcurrent detection method for a power battery according to an embodiment of the present invention;

[0032] Figure 5 This is a structural block diagram of an overcurrent detection device for a power battery according to an embodiment of the present invention. Detailed Implementation

[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 an embodiment of the present invention, a method embodiment for overcurrent detection 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] Figure 1 This is a hardware structure block diagram of a vehicle terminal for an optional overcurrent detection method for a power battery according to an embodiment of the present invention, such as... Figure 1 As shown, the vehicle terminal 10 (or a mobile device 10 that communicates with the vehicle) may include one or more processors 102 (processor 102 may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.), a memory 104 for storing data, and a transmission device 106 for communication functions. In addition, it may also include: a display device 110, an input / output device 108 (i.e., I / O device), a universal serial bus (USB) port (which may be included as one of the ports of a BUS bus, not shown in the figure), a network interface (not shown in the figure), a power supply (not shown in the figure), and / or a camera (not shown in the figure). Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the vehicle terminal 1 described above. For example, the vehicle terminal 10 may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0037] It should be noted that the aforementioned one or more processors 102 and / or other data processing circuits may be embodied, in whole or in part, as software, hardware, firmware, or any other combination thereof. Furthermore, the data processing circuitry may be a single, independent processing module, or may be integrated, in whole or in part, into any other element within the vehicle terminal 10 (or mobile device).

[0038] The memory 104 can be used to store software programs and modules for application software, such as the program instructions / data storage device corresponding to the overcurrent detection method for a power battery in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the software programs and modules stored in the memory 104, thereby realizing the aforementioned overcurrent detection method for a power battery. The memory 104 may include high-speed random access memory, and may also include 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 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the vehicle terminal 10 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] The transmission device 106 is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the communication provider of the vehicle terminal 10. In one example, the transmission device 106 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 transmission device 106 may be a Radio Frequency (RF) module, used for wireless communication with the Internet.

[0040] Under the above operating environment, the embodiments of the present invention provide as follows: Figure 2 The overcurrent detection method for the power battery shown is as follows: Figure 2 This is a flowchart of an overcurrent detection method for a power battery according to an embodiment of the present invention, as shown below. Figure 2 As shown above, Figure 2 The embodiments shown may include at least the following implementation steps, namely, the technical solutions implemented by steps S21 to S23.

[0041] Step S21: Obtain the first current signal, the second current signal, the voltage signal, and the temperature signal corresponding to the power battery, wherein the first current signal is a digital signal and the second current signal is an analog signal;

[0042] In one optional solution provided by step S21 above, the power battery can be a power source for electric vehicles (including but not limited to pure electric vehicles and hybrid electric vehicles). The first current signal can be a current signal obtained based on a first current sensor, and the second current signal can be a current signal obtained based on a second current sensor. It should also be noted that in the solution provided by this invention, the first current sensor and the second current sensor are two current sensors with different principles and transmission paths. For example, the first current sensor can be a shunt-type current sensor, and the second current sensor can be a Hall sensor. The voltage signal and the temperature signal can be signals obtained after sampling by an analog-to-digital converter (ADC) using a sampling chip. It should also be noted that different models of sampling chips can be selected for sampling according to different sampling indicators (such as sampling rate, bit depth, power consumption, and cost). This embodiment of the invention does not specifically limit the model of the sampling chip.

[0043] Step S22: Perform sensor fault diagnosis and overcurrent detection based on the first current signal and the second current signal to obtain the first detection result;

[0044] In one optional solution provided by step S22 above, the first detection result may include, but is not limited to: whether the sensor corresponding to the first current signal is faulty, what kind of fault the sensor corresponding to the first current signal is, whether the sensor corresponding to the second current signal is faulty, what kind of fault the sensor corresponding to the second current signal is, whether the power battery is at risk of overcurrent, whether the first current signal reaches a preset safety level (such as ASIL-B), and whether the second current signal reaches a preset safety level (such as ASIL-B). It should also be noted that the fault may include, but is not limited to: zero drift fault, ground fault, short circuit to power supply fault, current out-of-range fault, power supply fault, and message reception fault.

[0045] In the solution provided by this invention, it should be noted that the automotive functional safety requirements (or the aforementioned preset safety levels) involved in this invention refer to the Automotive Safety Integrity Level (ASIL). This ASIL is a safety level standard defined by the International Organization for Standardization (ISO) 26262, which can be used to describe the safety of electronic or electronic systems in a vehicle, and can represent the potential level of danger and the necessary preventative measures in an automotive application. Specifically, the ASIL includes: ASIL-A, representing a low-risk level with accidental occurrence, suitable for occupant protection of ordinary drivers and passengers in accidental situations; ASIL-B, suitable for situations where specific risks and injury risks are reduced; ASIL-C, suitable for applications that are likely to lead to significant harm and death; and ASIL-D, suitable for actions specifically taken to address risks that are likely to lead to significant harm and death and are difficult to estimate (or when ensuring the correctness of actions). It should also be noted that in automotive functional safety requirements, Quality Management (QM) can be used to represent automotive functional safety requirements that meet quality management processes.

[0046] In the solution provided by the present invention, as an optional implementation, two current sensors with different principles and transmission paths are used to acquire a first current signal and a second current signal respectively. The signal value of the first current signal (or the second current signal) is measured, or the signal characteristics of the first current signal (or the second current signal) are analyzed to determine whether the sensor corresponding to the first current signal (or the second current signal) is faulty.

[0047] In the solution provided by this invention, as another optional implementation, two current sensors with different principles and transmission paths are used to acquire historical first current signals, real-time first current signals, historical second current signals, and real-time second current signals, respectively. The historical first current signal and the real-time first current signal are compared and analyzed to determine whether the sensor corresponding to the (historical or real-time) first current signal is faulty. Similarly, the historical second current signal and the real-time second current signal are compared and analyzed to determine whether the sensor corresponding to the (historical or real-time) second current signal is faulty. In addition, overcurrent detection is performed on the first current signal (or the second current signal) to make the overcurrent signal reach a preset safety level (ASIL-D).

[0048] Step S23: Perform rationality detection and overcurrent detection based on voltage signal, temperature signal and the opening and closing status of the contactor of the power battery to obtain the second detection result;

[0049] In one optional solution provided by step S23 above, the contactor can be a safety device connected to high-power applications in an electric vehicle. This safety device can possess functional characteristics such as high voltage resistance, load resistance, and impact resistance, and can be used to ensure the driving safety of the vehicle and the operational safety of its components. Specifically, for example, when the vehicle is powered off, the power battery and traction inverter can be electrically isolated through the main contactor. The second detection result mentioned above may include, but is not limited to: whether the voltage signal reaches the preset safety level (ASIL-D), whether the temperature signal reaches the preset safety level (ASIL-D), whether the contactor's state reaches the preset safety level (ASIL-D), and whether there is an overcurrent hazard in the power battery.

[0050] In one optional solution provided by step S23 above, the aforementioned rationality test may include, but is not limited to, voltage rationality verification. This voltage rationality verification ensures that, under load conditions of disconnection and connection, the measured voltage value should not be less than the rated minimum voltage requirement and not greater than the rated maximum voltage requirement. Furthermore, when the load is at full load, the obtained voltage should not be less than 85% of the rated minimum voltage requirement and not greater than 115% of the rated maximum voltage requirement. It should also be noted that voltage rationality verification ensures that all components of the system operate within their specified operating range, effectively guaranteeing the safe and reliable operation of the system.

[0051] In one optional solution provided by step S23 above, the aforementioned rationality test may include, but is not limited to, current rationality verification. This current rationality verification refers to verifying, based on the electrical equipment and system design parameters, whether all electrical components can withstand currents exceeding their capacity (or permissible values) during normal operation by checking the maximum current of each branch. It should also be noted that in actual current testing, current rationality verification is performed on the circuit before and after each component is installed. When an excessive current is detected in the circuit (e.g., exceeding three times the component's rated value), it indicates that one or more components in the circuit may suffer permanent damage.

[0052] In the solution provided by this invention, as an optional implementation, sensors are used to acquire voltage and temperature signals with higher reliability, and the voltage and temperature signals are tested for reasonableness to ensure that the voltage and temperature signals reach a preset safety level (ASIL-D); the opening and closing state of the power battery contactor is acquired, and the opening and closing state of the contactor is tested for reasonableness to ensure that the opening and closing state of the contactor reaches a preset safety level (ASIL-D); based on the voltage signal, current signal, and the opening and closing state of the contactor, overcurrent detection is performed on the current signal to ensure that the overcurrent signal reaches a preset safety level (ASIL-D).

[0053] Step S24: Based on the first detection result and the second detection result, determine the target overcurrent detection result corresponding to the power battery. The target overcurrent detection result is used to assist in the functional safety testing of the power battery.

[0054] In one optional solution provided by step S24 above, the target overcurrent detection result may include, but is not limited to: whether the sensor corresponding to the first current signal is faulty, what kind of fault the sensor corresponding to the first current signal is, whether the sensor corresponding to the second current signal is faulty, what kind of fault the sensor corresponding to the second current signal is, whether the power battery is in danger of overcurrent, whether the overcurrent signal of the power battery reaches the preset safety level (ASIL-D), and the current value of the power battery at the current moment.

[0055] In this embodiment of the invention, firstly, a first current signal, a second current signal, a voltage signal, and a temperature signal corresponding to the power battery are acquired, wherein the first current signal is a digital signal and the second current signal is an analog signal. Then, sensor fault diagnosis and overcurrent detection are performed based on the first current signal and the second current signal to obtain a first detection result. Next, rationality detection and overcurrent detection are performed based on the voltage signal, the temperature signal, and the opening and closing state of the power battery contactor to obtain a second detection result. Finally, based on the first detection result and the second detection result, a target overcurrent detection result corresponding to the power battery is determined, wherein the target overcurrent detection result is used to assist in the functional safety testing of the power battery.

[0056] As is easily understood, this invention improves the accuracy and safety of overcurrent detection by performing rationality and overcurrent detection on the first and second current signals, voltage signals, temperature signals, and the opening and closing state of the contactor obtained by dual current sensors. This achieves the technical effect of combining voltage signals, temperature signals, and the opening and closing state of the contactor to perform overcurrent detection on the power battery, thereby improving the accuracy and safety of overcurrent detection. Furthermore, it solves the technical problem of low accuracy and poor safety in existing functional safety testing methods for power batteries that rely solely on current sensors for overcurrent detection.

[0057] The methods described in the embodiments of the present invention will be further described below.

[0058] In an optional embodiment, step S21, obtaining the first current signal and the second current signal corresponding to the power battery includes:

[0059] Step S211: Control the first sensor to collect current data to generate a first current signal, and control the second sensor to collect current data to generate a second current signal, wherein the first sensor and the second sensor are connected to the power battery.

[0060] In one optional solution provided by step S211 above, the first sensor can be a shunt-type current sensor connected to the power battery. This shunt-type current sensor is made based on the principle that a voltage is generated across a resistor when a direct current flows through it, and can be used to measure direct current and acquire a digital signal of the current. It should also be noted that this shunt-type current sensor can be a current-voltage-temperature (IVT) sensor. The second sensor can be a Hall current sensor connected to the power battery. This Hall current sensor is made based on the Hall effect and can be used to convert a changing magnetic field into a change in output voltage, and can acquire an analog signal of the current.

[0061] In an optional embodiment, in step S22, sensor fault diagnosis and overcurrent detection are performed based on the first current signal and the second current signal to obtain a first detection result, including:

[0062] Step S221: Determine the allowable current value of the power battery under the current operating condition based on the charge and discharge state parameters of the power battery. The charge and discharge state parameters include: charge and discharge mode, current temperature, current voltage and current charge.

[0063] Step S222: Perform fault diagnosis on the first sensor and the second sensor to obtain the diagnosis results;

[0064] Step S223: Based on the first current signal, the second current signal, the allowable current value, and the diagnostic results, perform overcurrent detection on the power battery to obtain the first detection result.

[0065] In the optional solutions provided in steps S221 to S223 above, the aforementioned charge / discharge state parameters may include, but are not limited to: charge / discharge mode, current temperature, current voltage, and current charge level, which can be used to characterize the current charge (or discharge) state of the power battery. The aforementioned current operating condition may be the operating status of the electric vehicle during its current driving process, which may include, but is not limited to: acceleration, deceleration, uphill driving, turning, and stopping. The aforementioned allowable current value may be the safe current value allowed for the electric vehicle's power battery under the aforementioned current operating condition. The aforementioned charge / discharge mode may include, but is not limited to: DC charging mode, AC charging mode, and discharging mode. The aforementioned current charge level (State of Charge, SOC) may refer to the current remaining charge of the power battery. This charge / discharge state parameter can be expressed as a percentage; for example, 100% indicates that the power battery is fully charged, and 0% indicates that the power battery is fully discharged.

[0066] In the optional solutions provided in steps S221 to S223 above, the diagnostic result may be whether the first sensor (second sensor) is faulty, and the type of fault present in the first sensor (second sensor) (such as loss of current measurement signal or damage to current measurement signal).

[0067] The following combination Figure 3 , Figure 4 The above methods will be further explained.

[0068] Figure 3 This is a schematic diagram of an optional overcurrent detection process for a power battery according to an embodiment of the present invention. Figure 4 This is a flowchart of an optional overcurrent detection method for a power battery according to an embodiment of the present invention, such as... Figure 3 , 4 As shown, a first current signal (signal value denoted as I1) is acquired through an IVT current sensor (i.e., the aforementioned shunt-type current sensor), and a second current signal (signal value denoted as I2) is acquired through a Hall current sensor. This determines the current operating mode of the power battery (i.e., the aforementioned current operating condition). Furthermore, the current voltage signal (i.e., the aforementioned current voltage) and temperature signal (i.e., the aforementioned current temperature) of the power battery are acquired. Based on these voltage and temperature signals, the SOC retrieves the current allowable current value of the power battery (signal value denoted as I4) from the map (MAP) table for the current operating mode. It should be noted that the MAP table can be a table pre-stored in the electronic control unit (ECU) of the electric vehicle. This MAP table can contain parameters or information (such as allowable current value and location information) for the electric vehicle in different operating modes.

[0069] Still as Figure 3 As shown, it should also be noted that in the solution provided by this invention, both the IVT current input and the Hall current input meet the automotive functional safety requirements of the Quality Management (QM) process. Furthermore, when diagnosing faults in the IVT current sensor and the Hall current sensor, the safety level of the current signal can be downgraded (e.g., from ASIL-D to ASIL-B).

[0070] Still as Figure 3 , 4 As shown, during the overcurrent detection process of the power battery, fault diagnosis is performed on the IVT current sensor (first current sensor) and the Hall current sensor (second current sensor). When both current sensors are faulty (or the first current signal measured by the IVT current sensor and the second current signal measured by the Hall current sensor are both invalid), it indicates that the current current signal of the power battery is invalid. At this time, the current value of the power battery is set to an invalid value (i.e., the first detection result mentioned above).

[0071] Still as Figure 3 , 4 As shown, when both the first current signal measured by the IVT current sensor and the second current signal measured by the Hall current sensor are valid, the difference between the first current signal and the second current signal is calculated. When the difference does not meet the current verification condition (e.g., the difference is greater than the preset current verification value), it indicates that the current current signal of the power battery is invalid. At this time, the current value of the power battery is set to an invalid value (i.e., the first detection result mentioned above).

[0072] Still as Figure 3 , 4 As shown, when the difference between the first current signal and the second current signal meets the current verification condition (such as the difference being less than or equal to the preset current verification value), it indicates that the current current signal of the power battery is valid. Then, the first current signal and the second current signal are calculated (such as weighted calculation) to obtain the valid value of the current current signal of the power battery (i.e., the first detection result mentioned above).

[0073] In the above optional embodiments, the technical effects that can be achieved are as follows: by using a first sensor and a second sensor with different principles and transmission paths to acquire the first current signal and the second current signal respectively, the problems of inaccurate current values ​​acquired by a single sensor and inability to acquire current when a single sensor fails can be avoided; furthermore, by performing fault diagnosis on the first sensor and the second sensor, and by performing rationality verification and overcurrent detection on the current, the accuracy of the current verification results can be improved, thereby improving the accuracy of the overcurrent detection results; and, during the fault diagnosis, rationality verification, and overcurrent detection process, the safety level of the current signal is adaptively adjusted, which can improve the adaptability of the power battery functional safety testing method to the functional safety requirements of automobiles.

[0074] In an optional embodiment, in step S223, overcurrent detection is performed on the power battery based on the first current signal, the second current signal, the allowable current value, and the diagnostic result to obtain the first detection result, which includes:

[0075] Step S2231: In response to the fault diagnosis that the first sensor is not faulty and the second sensor is faulty, the first current value is determined as the target current value, wherein the first current value is the current current value corresponding to the first current signal;

[0076] Step S2232: In response to the fault diagnosis that the first sensor has failed and the second sensor has not failed, the second current value is determined as the target current value, wherein the second current value is the current current value corresponding to the second current signal;

[0077] Step S2233: In response to the fault diagnosis that neither the first sensor nor the second sensor has failed, and the difference between the first current value and the second current value is less than a preset error threshold, the first current value and the second current value are weighted and calculated to obtain the target current value.

[0078] Step S2234: In response to the target current value exceeding the allowable current value, the first detection result is determined to be an overcurrent fault in the power battery.

[0079] In the optional solutions provided in steps S2231 to S2234 above, the first current value can be the current value corresponding to the first current signal in the current operating mode. The target current value can refer to the current value of the power battery in the current operating mode. The second current value can be the current value corresponding to the second current signal in the current operating mode. The preset error threshold can be a verification value of the power battery current signal predetermined by a technician. This preset error threshold can be used to determine whether the power battery current signal is valid. Specifically, for example, when the difference between the first current value and the second current value is less than (or equal to) the preset error threshold, it can be determined that the power battery current signal verification is successful (e.g., indicating that the current signal is valid). For another example, when the difference between the first current value and the second current value is greater than the preset error threshold, it can be determined that the power battery current signal verification fails (e.g., indicating that the current signal is invalid). It should also be noted that the preset error threshold can be presented in numerical or percentage form.

[0080] In the solution provided by this invention, the aforementioned overcurrent fault can include multiple fault levels. Specifically, under the current operating condition of the electric vehicle, multiple overcurrent values ​​can be preset according to the current magnitude, and each overcurrent value corresponds to a fault level. As an optional implementation, when the electric vehicle is accelerating, the preset overcurrent fault table can be as shown in Table 1 below:

[0081] Table 1

[0082] Overcurrent value Fault Level <![CDATA[I a ]]> Grade A <![CDATA[I b ]]> Grade B <![CDATA[I c ]]> Class C <![CDATA[I d ]]> Class D

[0083] In Table 1 above, specifically, for example, when the target current value (denoted as I) satisfies I a ≤I b At this time, it can be determined that the power battery currently has an overcurrent fault, and the current overcurrent fault level is Class A. For example, when the target current value satisfies I... c ≤I d At this time, it can be determined that the power battery is currently experiencing an overcurrent fault, and the current overcurrent fault level is C.

[0084] Still as Figure 3 , 4 ​​As shown, firstly, fault diagnosis is performed on the first current sensor (IVT current sensor) and the second current sensor (Hall current sensor) for errors (such as power supply errors), and the fault diagnosis results are sent to the Battery Management System (BMS).

[0085] The specific method for fault diagnosis of the first current sensor provided by this invention can be as follows: Read the current signal measurement value on the internal control area network (CAN) bus every preset time period (e.g., 10ms), and detect fault information (such as loss information, damage information, or stall information) of the current signal measurement value on the CAN bus based on the rolling counter and Cyclic Redundancy Check (CRC) data connected to the CAN bus; if the first current sensor is faulty, the fault may include, but is not limited to: receiving incorrect data, receiving invalid values, not receiving messages, or power supply exceeding the range. In this case, the current signal state of the first current sensor is set to invalid and the fault of the first current sensor is reported; furthermore, if the current signal state of the first current sensor is diagnosed as invalid, and it is detected that both the main positive and main negative contactors are in a closed state, then the fault information is reported and the vehicle user is reminded to perform timely fault repair.

[0086] The specific method for fault diagnosis of the Hall current sensor provided by this invention may be as follows: diagnose the Hall current sensor within a preset time (e.g., 100ms); if the Hall current sensor is faulty, the fault may include, but is not limited to: short circuit to ground, short circuit to battery, open circuit, power supply out of range, current value out of range, in which case, the current signal state of the Hall current sensor is set to invalid and the Hall current sensor fault is reported; furthermore, if the current signal state of the Hall current sensor is diagnosed as invalid, and it is detected that both the main positive and main negative contactors are in a closed state, then the fault information is reported and the car user is reminded to perform fault repair in a timely manner.

[0087] Still as Figure 3 , 4As shown, after fault diagnosis of the first current sensor and the second current sensor, when the first current sensor has no fault and the second current sensor has a fault, report the fault of the second current sensor, and determine the above first current value as the target current value, that is, I = I1; when the first current sensor has a fault and the second current sensor has no fault, report the fault of the first current sensor, and determine the above second current value as the target current value, that is, I = I2; when the first current sensor has a fault and the second current sensor both have faults, report the faults of the first current sensor and the second current sensor, and report that the current is invalid. At the same time, announce the system fault type and take a series of vehicle safety protection measures (such as prohibiting battery charging and restricting the use of the vehicle).

[0088] Still as Figure 3 、 4 shown, when the difference between the first current value and the second current value is greater than the preset error threshold (that is, |I1 - I2| > I3) and it is detected that the main positive and main negative contactors are closed, it indicates that the current signal of the power battery is invalid. At this time, report that the current is invalid, announce the system fault type, and take a series of vehicle safety protection measures (such as restricting the allowable power of the power battery to zero, cutting off the contactor within 300 ms, and not responding to the high-voltage power-on request).

[0089] Still as Figure 3 、 4 shown, when the first current sensor has a fault and the second current sensor has no faults, determine the difference between the first current value and the second current value, and compare it with the preset error threshold (denoted as I3) for judgment. When the difference between the first current value and the second current value is less than (or equal to) the preset error threshold (that is, |I1 - I2| ≤ I3), it indicates that the current signal of the power battery is valid. Further, use the Battery Management Unit (BMU) to perform weighted calculation on the first current value and the second current value to obtain the target current value I, that is, I = I1 × K1 + I2 × K2, where K1 is the weight value of the first current value I1, and K2 is the weight value of the second current value I2. Here, it should also be noted that K1 and K2 can be determined according to the accuracy of the first current sensor and the second current sensor, and satisfy K1 + K2 = 1. Further, compare the target current value with the allowable current value. When the target current value is less than the allowable current value (that is, I < I4), it indicates that the current value of the power battery is valid. At this time, report the current target current value; when the target current value is greater than (or equal to) the allowable current value (that is, I ≥ I4), it indicates that the power battery has an overcurrent fault. At this time, perform overcurrent protection operations according to different fault levels corresponding to the current working conditions (such as sequentially cutting off the contactor and not responding to the high-voltage power-on request).

[0090] In the above optional embodiments, the technical effects that can be achieved are as follows: Before performing overcurrent detection on the power battery, a comprehensive fault diagnosis is performed on the current sensors (including the first current sensor and the second current sensor mentioned above), which can avoid the problem that the overcurrent detection of the power battery cannot be performed due to the fault of the current sensor itself (or the overcurrent detection result of the power battery is inaccurate or has a large error), and improve the accuracy of the overcurrent detection result; and, by using current sensors with different principles and transmission paths to obtain current signals (including the first current signal and the second current signal mentioned above), the problem of inaccurate current values ​​obtained by a single sensor and the inability to obtain current when a single sensor fails can be avoided, and the accuracy of the overcurrent detection result can be improved; in addition, during the overcurrent detection process, the safety level of the current signal is adaptively adjusted, which can improve the adaptability of the functional safety testing method of the power battery to the functional safety requirements of automobiles.

[0091] In an optional embodiment, in step S23, based on the voltage signal, temperature signal, and the opening / closing state of the contactor of the power battery, a rationality test and an overcurrent test are performed to obtain a second test result, including:

[0092] Step S231: Perform a rationality test on the voltage signal, temperature signal, and the opening and closing status of the contactor of the power battery to obtain the third test result;

[0093] In step S232, in response to the third detection result meeting the preset vehicle safety integrity level conditions, overcurrent detection is performed based on voltage and temperature signals to obtain the second detection result.

[0094] In the optional solutions provided in steps S231 to S232 above, the aforementioned rationality testing may include, but is not limited to: voltage rationality testing, temperature rationality testing, and contactor rationality testing. The aforementioned third result may include, but is not limited to, one or more rationality testing results from the voltage rationality testing, temperature rationality testing, and contactor rationality testing. The aforementioned preset vehicle safety integrity level condition may be that the aforementioned voltage rationality testing, temperature rationality testing, and contactor rationality testing meet the ASIL-D safety level. The aforementioned second test result may be the test result obtained by performing overcurrent testing on the voltage signal and temperature signal in the third test result that meets the preset vehicle safety integrity level condition.

[0095] In an optional embodiment, in step S231, a reasonableness test is performed on the voltage signal, temperature signal, and the open / closed state of the power battery contactor to obtain a third test result, including:

[0096] Step S2311: Perform range rationality detection on the voltage signal and temperature signal to obtain the fourth detection result;

[0097] Step S2312: Perform a disconnection rationality test on the open / closed state of the power battery contactor to obtain the fifth test result;

[0098] Step S2313: In response to the fact that both the fourth and fifth test results meet the preset vehicle safety integrity level conditions, it is determined that the third test result meets the preset vehicle safety integrity level conditions.

[0099] In the optional solutions provided in steps S2311 to S2313 above, the fourth detection result may include the voltage rationality test and the temperature rationality test meeting the preset vehicle safety integrity level condition (ASIL-D). The fifth detection result may be the contactor rationality test (i.e., the rationality test of the opening and closing state of the power battery contactor) meeting the preset vehicle safety integrity level condition (ASIL-D).

[0100] In the solution provided by this invention, the rationality of the opening and closing state of the power battery contactor is tested to obtain a fifth test result. The specific method may be: performing state diagnosis and rationality verification on the main positive and main negative contactors of the power battery. The state diagnosis and rationality verification may include, but are not limited to: contactor hardware error monitoring, contactor state detection, contactor timing monitoring, contactor adhesion monitoring, contactor request monitoring, and contactor disconnection rationality verification; and performing disconnection rationality verification on the contactors. The disconnection rationality verification may include, but is not limited to: when the main positive and main negative contactors are detected to be disconnected, the detected battery current value exceeds a certain range (such as exceeding the minimum battery current value required by the vehicle under a certain operating condition) and the battery current detection is normal.

[0101] In the above optional embodiments, the technical effects that can be achieved are as follows: by utilizing the more mature voltage and temperature rationality detection technologies, high-accuracy voltage and temperature signals can be obtained. Furthermore, by using voltage and temperature rationality detection to assist in overcurrent detection, overcurrent fault scenarios that cannot be detected by current detection methods can be covered, thereby expanding the detection scenarios of the power battery functional safety testing method, improving the accuracy of the power battery overcurrent detection results, and enhancing the safety of overcurrent detection. In addition, by adaptively adjusting the safety levels of the fourth and fifth detection results, the adaptability of the power battery functional safety testing method to automotive functional safety requirements can be improved.

[0102] In an optional embodiment, in step S232, in response to the third detection result satisfying the preset vehicle safety integrity level condition, overcurrent detection is performed based on voltage and temperature signals to obtain a second detection result, including:

[0103] Step S2321: Using the voltage safety mechanism, overcurrent detection is performed on the voltage signal to obtain the sixth detection result. The voltage safety mechanism is used to determine whether the power battery has an overcurrent fault based on the overcurrent voltage change rules of the power battery.

[0104] Step S2322: Using the temperature safety mechanism, the temperature signal is overcurrent detected to obtain the seventh detection result. The temperature safety mechanism is used to determine whether the power battery has an overcurrent fault based on the overcurrent temperature change rule of the power battery.

[0105] Step S2323: In response to at least one of the sixth and seventh detection results being an overcurrent fault in the power battery, determine the second detection result as an overcurrent fault in the power battery.

[0106] In the optional solutions provided in steps S2321 to S2323 above, the sixth detection result may include whether an overcurrent fault has occurred in the power battery based on a voltage signal. The seventh detection result may include whether an overcurrent fault has occurred in the power battery based on a temperature signal. The overcurrent temperature change rule may be the temperature rise caused by overcurrent.

[0107] In the solution provided by this invention, considering the voltage changes during overcurrent heating and overcurrent lithium plating (single occurrence), a voltage safety mechanism is used to detect voltage rationality to cover overcurrent, and a temperature safety mechanism is used to detect temperature rationality to cover overcurrent. Specifically, the voltage safety mechanism may include, but is not limited to: open-circuit detection, leakage current detection, voltage monitoring, battery voltage detection, battery voltage rationality monitoring, single-cell voltage ineffectiveness monitoring, single-cell overvoltage monitoring, and single-cell undervoltage monitoring; the temperature safety mechanism may include, but is not limited to: module temperature detection, module temperature effectiveness and rationality monitoring, module over-temperature monitoring, module low-temperature charging monitoring, coolant inlet temperature monitoring, and coolant temperature rationality monitoring.

[0108] In the above optional embodiments, the technical effects that can be achieved are as follows: by utilizing the more mature voltage and temperature rationality detection technologies, highly reliable voltage and temperature signals can be obtained. Furthermore, by using voltage and temperature rationality detection to assist in overcurrent detection, overcurrent fault scenarios that cannot be detected by current detection methods can be covered, thereby expanding the overcurrent detection scenarios of power batteries, improving the overcurrent detection safety level, improving the accuracy of overcurrent detection results, and enhancing overcurrent detection safety. In addition, by adaptively adjusting the safety levels of the sixth and seventh detection results, the adaptability of the power battery functional safety testing method to automotive functional safety requirements can be improved.

[0109] In an optional embodiment, in step S24, determining the target overcurrent detection result corresponding to the power battery based on the first detection result and the second detection result includes:

[0110] Step S241: In response to at least one of the first detection result and the second detection result being an overcurrent fault in the power battery, determine the target overcurrent detection result as an overcurrent fault in the power battery.

[0111] The following combination Figure 3 The above methods will be further explained.

[0112] Still as Figure 3 As shown, after using two current sensors with different principles and transmission paths to perform current rationality verification (i.e., the aforementioned current rationality detection), when the current rationality verification passes and meets the ASIL-D level, an overcurrent detection is performed on the power battery to obtain the first detection result. After performing voltage rationality verification (i.e., the aforementioned voltage rationality detection) and temperature rationality verification (i.e., the aforementioned temperature rationality detection), based on the voltage rationality verification result, temperature rationality verification result, contactor status diagnosis, and rationality verification result, the current request is rationally verified. When the current request rationality verification passes and meets the ASIL-D level, an overcurrent detection is performed on the power battery to obtain the second detection result. Furthermore, when at least one of the first and second detection results indicates that the power battery has an overcurrent fault, it indicates that the power battery has an overcurrent fault, and the target overcurrent detection result is output.

[0113] Still as Figure 3 As shown, it should also be noted that in the solution provided by the present invention, both the voltage input and temperature input meet the automotive functional safety requirements of the quality management (QM) process.

[0114] In the above optional embodiments, the technical effects that can be achieved are as follows: by performing mutual verification (i.e., the first current signal and the second current signal) through dual redundant current (i.e., the above current rationality verification), the accuracy of the first current signal and the second current signal can be improved, thereby improving the accuracy of the overcurrent detection results of the power battery; and by using highly reliable voltage and temperature signals, and by covering the temperature rise and voltage drop caused by overcurrent conditions through voltage safety mechanisms and temperature safety mechanisms, the overcurrent detection scenario can be expanded, the accuracy of the overcurrent detection results can be improved, the overcurrent detection safety level can be improved, and the overcurrent detection safety can be enhanced.

[0115] In an optional embodiment, the functional safety testing method for power batteries provided by the present invention further includes:

[0116] Step S25: In response to the target overcurrent detection result indicating an overcurrent fault in the power battery, an overcurrent alarm message is generated, and the power battery is controlled to perform an overcurrent protection operation, wherein the overcurrent protection operation includes at least one of the following: charging power limiting, discharging power limiting, and contactor disconnection.

[0117] In the optional solution provided in step S25 above, the overcurrent alarm message can be used to promptly remind the vehicle user of an overcurrent fault, enabling the user to perform corresponding manual overcurrent protection operations in a timely manner to avoid driving hazards and reduce damage to the vehicle. It should also be noted that the overcurrent alarm message may include, but is not limited to, instrument panel prompts and in-vehicle voice alarm messages. The overcurrent protection operation can consist of a series of control commands, which can be automatically executed by the ECU when an overcurrent fault occurs in the power battery.

[0118] In the above optional embodiments, the technical effect that can be achieved is: when an overcurrent fault occurs in the power battery of an electric vehicle, an overcurrent alarm message is generated in a timely manner and provided to the vehicle user. At the same time, the overcurrent protection operation is executed autonomously, thereby avoiding (or reducing) the harm caused by the overcurrent fault of the power battery, and thus improving the intelligence level of the functional safety testing method of the power battery.

[0119] In this embodiment, an overcurrent detection device for a power battery is also provided. This device is used to implement the above embodiments and preferred embodiments, and details already described will not be repeated. As used below, a "module" is a combination of software and / or hardware that can perform 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.

[0120] Figure 5 This is a structural block diagram of an overcurrent detection device for a power battery according to an embodiment of the present invention, as shown below. Figure 5 As shown, the device includes:

[0121] The acquisition module 501 is used to acquire a first current signal, a second current signal, a voltage signal, and a temperature signal corresponding to the power battery, wherein the first current signal is a digital signal and the second current signal is an analog signal;

[0122] The first detection module 502 is used to perform sensor fault diagnosis and overcurrent detection based on the first current signal and the second current signal, and obtain the first detection result.

[0123] The second detection module 503 is used to perform rationality detection and overcurrent detection based on voltage signal, temperature signal and the opening and closing status of the contactor of the power battery, and obtain the second detection result;

[0124] The determination module 504 is used to determine the target overcurrent detection result corresponding to the power battery based on the first detection result and the second detection result, wherein the target overcurrent detection result is used to assist in the functional safety testing of the power battery.

[0125] Optionally, the acquisition module 501 is further configured to: acquire the first current signal and the second current signal corresponding to the power battery, including: controlling the first sensor to collect current data to generate the first current signal, and controlling the second sensor to collect current data to generate the second current signal, wherein the first sensor and the second sensor are connected to the power battery.

[0126] Optionally, the first detection module 502 is further configured to: perform sensor fault diagnosis and overcurrent detection based on the first current signal and the second current signal to obtain a first detection result, including: determining the allowable current value of the power battery under the current operating condition according to the charge and discharge state parameters of the power battery, wherein the charge and discharge state parameters include: charge and discharge mode, current temperature, current voltage and current charge; performing fault diagnosis on the first sensor and the second sensor to obtain a diagnosis result; and performing overcurrent detection on the power battery based on the first current signal, the second current signal, the allowable current value and the diagnosis result to obtain a first detection result.

[0127] Optionally, the first detection module 502 is further configured to: perform overcurrent detection on the power battery based on the first current signal, the second current signal, the allowable current value, and the diagnostic result, and obtain a first detection result including: in response to the fault diagnosis that the first sensor is not faulty and the second sensor is faulty, determining the first current value as the target current value, wherein the first current value is the current current value corresponding to the first current signal; in response to the fault diagnosis that the first sensor is faulty and the second sensor is not faulty, determining the second current value as the target current value, wherein the second current value is the current current value corresponding to the second current signal; in response to the fault diagnosis that neither the first sensor nor the second sensor is faulty, and the difference between the first current value and the second current value is less than a preset error threshold, performing a weighted calculation on the first current value and the second current value to obtain the target current value; in response to the target current value exceeding the allowable current value, determining that the first detection result indicates that the power battery has an overcurrent fault.

[0128] Optionally, the second detection module 503 is further configured to: perform rationality detection and overcurrent detection based on voltage signal, temperature signal and the opening and closing state of the contactor of the power battery, and obtain a second detection result including: performing rationality detection on voltage signal, temperature signal and the opening and closing state of the contactor of the power battery to obtain a third detection result; and, in response to the third detection result satisfying the preset vehicle safety integrity level conditions, performing overcurrent detection based on voltage signal and temperature signal to obtain a second detection result.

[0129] Optionally, the second detection module 503 is further configured to: perform reasonableness detection on the voltage signal, temperature signal, and the opening and closing state of the power battery contactor to obtain a third detection result, including: performing range reasonableness detection on the voltage signal and temperature signal to obtain a fourth detection result; performing disconnection reasonableness detection on the opening and closing state of the power battery contactor to obtain a fifth detection result; and determining that the third detection result meets the preset vehicle safety integrity level conditions in response to both the fourth and fifth detection results.

[0130] Optionally, the second detection module 503 is further configured to: perform overcurrent detection based on voltage and temperature signals to obtain a second detection result, including: using a voltage safety mechanism to perform overcurrent detection on the voltage signal to obtain a sixth detection result, wherein the voltage safety mechanism is used to determine whether the power battery has experienced an overcurrent fault according to the overcurrent voltage change rule of the power battery; using a temperature safety mechanism to perform overcurrent detection on the temperature signal to obtain a seventh detection result, wherein the temperature safety mechanism is used to determine whether the power battery has experienced an overcurrent fault according to the overcurrent temperature change rule of the power battery; and in response to at least one of the sixth and seventh detection results indicating that the power battery has experienced an overcurrent fault, determine that the second detection result is that the power battery has experienced an overcurrent fault.

[0131] Optionally, the determining module 504 is further configured to: determine the target overcurrent detection result corresponding to the power battery based on the first detection result and the second detection result, including: in response to at least one of the first detection result and the second detection result being an overcurrent fault in the power battery, determine the target overcurrent detection result as an overcurrent fault in the power battery.

[0132] 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.

[0133] According to another aspect of the present invention, a vehicle is also provided, including an on-board memory and an on-board processor, characterized in that the on-board memory stores a computer program, and the on-board processor is configured to run the computer program to execute the power battery functional safety testing method described in any of the preceding embodiments.

[0134] Optionally, in this embodiment, the on-board storage can be configured to store a program for performing the following steps:

[0135] Step S1: Obtain the first current signal, the second current signal, the voltage signal, and the temperature signal corresponding to the power battery, wherein the first current signal is a digital signal and the second current signal is an analog signal;

[0136] Step S2: Perform sensor fault diagnosis and overcurrent detection based on the first current signal and the second current signal to obtain the first detection result;

[0137] Step S3: Based on the voltage signal, temperature signal, and the opening and closing status of the contactor of the power battery, perform rationality detection and overcurrent detection to obtain the second detection result;

[0138] Step S4: Based on the first detection result and the second detection result, determine the target overcurrent detection result corresponding to the power battery. The target overcurrent detection result is used to assist in the functional safety testing of the power battery.

[0139] Optionally, in this embodiment, the aforementioned vehicle-mounted storage device 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.

[0140] Optionally, in this embodiment, the on-board processor can be configured to perform the following steps via a computer program:

[0141] Step S1: Obtain the first current signal, the second current signal, the voltage signal, and the temperature signal corresponding to the power battery, wherein the first current signal is a digital signal and the second current signal is an analog signal;

[0142] Step S2: Perform sensor fault diagnosis and overcurrent detection based on the first current signal and the second current signal to obtain the first detection result;

[0143] Step S3: Based on the voltage signal, temperature signal, and the opening and closing status of the contactor of the power battery, perform rationality detection and overcurrent detection to obtain the second detection result;

[0144] Step S4: Based on the first detection result and the second detection result, determine the target overcurrent detection result corresponding to the power battery. The target overcurrent detection result is used to assist in the functional safety testing of the power battery.

[0145] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments and their optional implementations, which will not be repeated here.

[0146] 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.

[0147] 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.

[0148] In the several embodiments provided by this invention, 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 example, 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 can be through some interfaces; the indirect coupling or communication connection of units or modules can be electrical or other forms.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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 functional safety detection of a power battery, characterized in that, The method comprises: obtaining a first current signal, a second current signal, a voltage signal and a temperature signal corresponding to a power battery, wherein the first current signal is a digital signal, and the second current signal is an analog signal; determining an allowable current value of the power battery in a current working condition according to a charging and discharging state parameter of the power battery, wherein the charging and discharging state parameter comprises a charging and discharging mode, a current temperature, a current voltage and a current power; performing fault diagnosis on a first sensor and a second sensor to obtain a diagnosis result, wherein the first sensor is used to detect the first current signal, and the second sensor is used to detect the second current signal; wherein the fault diagnosis on the first sensor comprises: reading a current current signal measurement value on an internal control domain local area network bus every first preset time period; detecting fault information of the current current signal measurement value according to a rolling counter and a cyclic redundancy check data connected with the internal control domain local area network bus; in response to determining that the first sensor has a fault according to the fault information, setting a current signal state of the first sensor as invalid; in response to the current signal state of the first sensor being invalid and detecting that both a main positive contactor and a main negative contactor are in a closed state, reporting the fault information to remind a user of the automobile to perform fault maintenance in a timely manner; performing overcurrent detection on the power battery based on the first current signal, the second current signal, the allowable current value and the diagnosis result to obtain a first detection result; wherein the overcurrent detection on the power battery based on the first current signal, the second current signal, the allowable current value and the diagnosis result to obtain the first detection result comprises: in response to the diagnosis result of the fault diagnosis being that neither the first sensor nor the second sensor has a fault, and a difference between a first current value corresponding to the first current signal and a second current value corresponding to the second current signal being less than a preset error threshold, performing weighted calculation on the first current value and the second current value to obtain a target current value; in response to the target current value exceeding the allowable current value, determining that the first detection result is that the power battery has an overcurrent fault; performing rationality detection and overcurrent detection based on the voltage signal, the temperature signal and an open and close state of a contactor of the power battery to obtain a second detection result; determining a target overcurrent detection result corresponding to the power battery according to the first detection result and the second detection result, wherein the target overcurrent detection result is used to assist in performing functional safety detection on the power battery.

2. The method for functional safety detection of a power battery according to claim 1, characterized in that, The method comprises: controlling a first sensor to collect current data to generate the first current signal, and controlling a second sensor to collect current data to generate the second current signal, wherein the first sensor and the second sensor are connected with the power battery.

3. The method for functional safety detection of a power battery according to claim 1, characterized in that, The overcurrent detection is performed on the power battery based on the first current signal, the second current signal, the allowable current value and the diagnosis result, and the first detection result comprises: In response to the diagnosis result of the fault diagnosis being that the first sensor does not fail and the second sensor fails, a first current value is determined as a target current value, where the first current value is a current value corresponding to the first current signal; In response to the diagnosis result of the fault diagnosis being that the first sensor fails and the second sensor does not fail, a second current value is determined as the target current value, where the second current value is a current value corresponding to the second current signal.

4. The method for functional safety detection of a power battery according to claim 1, characterized in that, The rationality detection and the overcurrent detection are performed based on the voltage signal, the temperature signal and the on-off state of a contactor of the power battery, and the second detection result comprises: The rationality detection is performed on the voltage signal, the temperature signal and the on-off state of the contactor of the power battery, and a third detection result is obtained; In response to the third detection result meeting a preset automotive safety integrity level condition, the overcurrent detection is performed based on the voltage signal and the temperature signal, and the second detection result is obtained.

5. The method for functional safety detection of a power battery according to claim 4, characterized in that, The rationality detection is performed on the voltage signal, the temperature signal and the on-off state of the contactor of the power battery, and a third detection result is obtained, which comprises: The range rationality detection is performed on the voltage signal and the temperature signal, and a fourth detection result is obtained; The disconnection rationality detection is performed on the on-off state of the contactor of the power battery, and a fifth detection result is obtained; In response to the fourth detection result and the fifth detection result both meeting the preset automotive safety integrity level condition, it is determined that the third detection result meets the preset automotive safety integrity level condition.

6. The method for functional safety detection of a power battery according to claim 4, characterized in that, In response to the third detection result meeting a preset automotive safety integrity level condition, the overcurrent detection is performed based on the voltage signal and the temperature signal, and the second detection result is obtained, which comprises: The overcurrent detection is performed on the voltage signal by using a voltage safety mechanism, and a sixth detection result is obtained, where the voltage safety mechanism is used to determine whether the power battery fails in overcurrent according to an overcurrent voltage variation rule of the power battery; The overcurrent detection is performed on the temperature signal by using a temperature safety mechanism, and a seventh detection result is obtained, where the temperature safety mechanism is used to determine whether the power battery fails in overcurrent according to an overcurrent temperature variation rule of the power battery; In response to at least one of the sixth detection result and the seventh detection result being that the power battery fails in overcurrent, it is determined that the second detection result is that the power battery fails in overcurrent.

7. The method for functional safety detection of a power battery according to claim 1, characterized in that, The target overcurrent detection result corresponding to the power battery is determined according to the first detection result and the second detection result, which comprises: In response to at least one of the first detection result and the second detection result being that the power battery fails in overcurrent, it is determined that the target overcurrent detection result is that the power battery fails in overcurrent.

8. A device for detecting overcurrent of a power battery, characterized in that, which comprises: The acquisition module is configured to acquire a first current signal, a second current signal, a voltage signal, and a temperature signal corresponding to the power battery, wherein the first current signal is a digital signal, and the second current signal is an analog signal; The first detection module is configured to determine an allowable current value of the power battery in a current working condition according to a charging and discharging state parameter of the power battery, wherein the charging and discharging state parameter includes a charging and discharging mode, a current temperature, a current voltage, and a current power; perform fault diagnosis on a first sensor and a second sensor to obtain a diagnosis result, wherein the first sensor is configured to detect the first current signal, and the second sensor is configured to detect the second current signal; wherein the fault diagnosis on the first sensor includes reading a current current signal measurement value on an internal control domain local area network bus every first preset time period; detecting fault information of the current current signal measurement value according to a rolling counter and a cyclic redundancy check data connected to the internal control domain local area network bus; in response to determining that the first sensor has a fault according to the fault information, setting a current signal state of the first sensor as invalid; in response to the current signal state of the first sensor being invalid and detecting that both a main positive contactor and a main negative contactor are in a closed state, reporting the fault information to remind a user of the automobile to perform fault maintenance in a timely manner; performing overcurrent detection on the power battery based on the first current signal, the second current signal, the allowable current value, and the diagnosis result to obtain a first detection result; wherein the overcurrent detection on the power battery based on the first current signal, the second current signal, the allowable current value, and the diagnosis result to obtain the first detection result includes: in response to the diagnosis result of the fault diagnosis being that neither the first sensor nor the second sensor has a fault, and a difference between a first current value corresponding to the first current signal and a second current value corresponding to the second current signal being less than a preset error threshold, performing weighted calculation on the first current value and the second current value to obtain a target current value; in response to the target current value exceeding the allowable current value, determining that the first detection result is that the power battery has an overcurrent fault; The second detection module is configured to perform rationality detection and overcurrent detection based on the voltage signal, the temperature signal, and an open and close state of a contactor of the power battery to obtain a second detection result; The determination module is configured to determine a target overcurrent detection result corresponding to the power battery according to the first detection result and the second detection result, wherein the target overcurrent detection result is used to assist in performing functional safety detection on the power battery.

9. A vehicle comprising an on-board memory and an on-board processor, characterized in that The vehicle-mounted memory stores a computer program, and the vehicle-mounted processor is configured to run the computer program to perform the functional safety detection method of the power battery in any one of claims 1 to 7.

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