Method and device for determining SOC (State of Charge) of power battery

Abstract

The invention provides a method and device for determining the SOC of a power battery, and the method comprises the steps: determining the SOC of the power battery if the SOC calibration condition of the power battery is satisfied at the power-on moment of a BMS of a vehicle; if yes, the SOC of the power battery at the current moment is determined according to a failure combination of the temperature of the power battery at the current moment, the effectiveness of the single voltage of the power battery at the current moment and the effectiveness of the SOC of the power battery stored when the BMS is powered off last time; if the SOC calibration condition of the power battery is not met, the SOC of the power battery at the current moment is determined according to the validity of the power battery temperature stored when the BMS is powered off last time; and at the BMS operation moment of the vehicle, the SOC of the power battery at the current moment is determined according to the effectiveness of the single voltage of the power battery at the current moment and the effectiveness of the current of the power battery at the current moment. According to the method and the device, the condition that the SOC is abnormal can be effectively reduced, and the SOC estimation precision is improved.

Description

Technical Field

[0001] The present application relates to the field of vehicle networking technology, and in particular to a method and device for determining the SOC of a power battery. Background Art

[0002] With the increasing global energy shortage and environmental pollution, the development of new energy vehicles has attracted more and more attention. As the energy carrier of new energy vehicles, the status monitoring of power batteries is particularly important. The battery management system (BMS) detects the status of each single battery in the power battery pack and adjusts the corresponding control strategy of the power battery system according to their status, thereby realizing the charge and discharge management of the power battery system to ensure its safe and stable operation. At present, the state of charge SOC estimation of the power battery is one of the cores of BMS. The accurate estimation of SOC plays an important role in optimizing the energy management of the whole vehicle, improving the capacity and energy utilization of the power battery, preventing the power battery from overcharging and over-discharging, and ensuring the safety and long life of the power battery during use. It can also bring protection for the driving safety of the driver.

[0003] However, SOC cannot be measured directly in BMS and can only be estimated indirectly through direct measurement parameters of the battery. Currently, the most commonly used SOC estimation method is the basic ampere-hour integration algorithm combined with the voltage correction algorithm. The above estimation methods all have the problems of SOC jumping, no change for a long time, and large deviation, which seriously affect the user experience. Summary of the invention

[0004] In view of this, the purpose of the embodiments of the present application is to provide a method and device for determining the SOC of a power battery. This solution can fully consider the impact of failures such as current, voltage and temperature on SOC estimation, and calculate the SOC under different failure combinations. In this way, it is possible to effectively reduce the occurrence of SOC abnormalities and improve the accuracy of SOC estimation.

[0005] In a first aspect, a method for determining a power battery SOC is provided, the method comprising:

[0006] At the moment when the BMS of the vehicle is powered on, if the SOC calibration condition of the power battery is met, the SOC of the power battery at the current moment is determined according to the failure combination of the temperature of the power battery at the current moment, the validity of the single cell voltage of the power battery at the current moment, and the validity of the SOC of the power battery stored when the BMS was powered off last time; if the SOC calibration condition of the power battery is not met, the SOC of the power battery at the current moment is determined according to the validity of the power battery temperature stored when the BMS was powered off last time;

[0007] When the BMS of the vehicle is running, the SOC of the power battery at the current moment is determined according to the validity of the single cell voltage of the power battery at the current moment and the validity of the current of the power battery at the current moment.

[0008] Optionally, the SOC calibration condition of the power battery is the interval time between the power-on time of the current BMS and the power-off time of the last BMS;

[0009] Meeting the SOC calibration condition of the power battery means that the interval between the power-on time of the current BMS and the power-off time of the last BMS is greater than the preset time;

[0010] Failure to meet the SOC calibration condition of the power battery means that the interval between the power-on time of the current BMS and the power-off time of the previous BMS is not greater than the preset time.

[0011] Optionally, if the SOC calibration condition of the power battery is met, the step of determining the SOC of the power battery at the current moment according to a failure combination of the temperature of the power battery at the current moment, the validity of the single cell voltage of the power battery at the current moment, and the validity of the SOC of the power battery stored when the BMS was powered off last time includes:

[0012] If the SOC calibration condition of the power battery is met, determine whether the single cell voltage of the power battery at the current moment is valid;

[0013] If the cell voltage is valid, determining whether the cell voltage is in a non-plateau region of a discharge characteristic curve;

[0014] If the cell voltage is in the non-platform region of the discharge characteristic curve, the SOC of the power battery at the current moment is determined by referring to the SOC-OCV curve according to the cell voltage and the temperature of the power battery at the current moment;

[0015] If the single cell voltage is not in the non-platform area of ​​the discharge characteristic curve, it is determined whether the SOC of the power battery stored when the BMS was powered off last time is valid; if the SOC of the power battery stored when the BMS was powered off last time is valid, the SOC of the power battery stored when the BMS was powered off last time is determined as the SOC of the power battery at the current moment; if the SOC of the power battery stored when the BMS was powered off last time is invalid, the SOC of the power battery at the current moment is determined by referring to the SOC-OCV curve based on the single cell voltage and the temperature of the power battery at the current moment.

[0016] Optionally, if the power battery SOC calibration condition is not met, the step of determining the SOC of the power battery at the current moment according to the validity of the power battery temperature stored when the BMS was powered off last time includes:

[0017] If the SOC calibration condition of the power battery is not met and the cell voltage is invalid, determining whether the SOC of the power battery stored when the BMS was powered off last time is valid;

[0018] If the SOC of the power battery stored when the BMS was powered off last time is valid, the SOC of the power battery stored when the BMS was powered off last time is determined as the SOC of the power battery at the current moment;

[0019] If the SOC of the power battery stored when the BMS was powered off last time is invalid, the open circuit voltage of the power battery at the time when the BMS is powered on is calculated according to the battery equivalent circuit model, and the SOC of the power battery at the current moment is determined by referring to the SOC-OCV curve based on the open circuit voltage and the temperature of the power battery at the current moment.

[0020] Optionally, the step of calculating the open circuit voltage of the power battery at the time when the BMS is powered on according to the battery equivalent circuit model includes:

[0021] Get the terminal voltage and polarization voltage during the last BMS power-off process;

[0022] The difference between the terminal voltage and the polarization voltage is determined as the open circuit voltage of the power battery when the BMS is powered on.

[0023] Optionally, the step of determining the SOC of the power battery at the current moment according to the validity of the single cell voltage of the power battery at the current moment and the validity of the current of the power battery at the current moment includes:

[0024] Determine whether the single cell voltage of the power battery is valid at the current moment;

[0025] If the single cell voltage of the power battery at the current moment is invalid, determine whether the current of the power battery at the current moment is valid;

[0026] If the current of the power battery at the current moment is invalid, the SOC of the power battery at the previous moment is used as the SOC of the power battery at the current moment;

[0027] If the current of the power battery at the current moment is valid, the SOC of the power battery at the current moment is estimated based on the current of the power battery at the current moment using the ampere-hour integration algorithm and the dynamic voltage correction algorithm.

[0028] Optionally, the step of determining the SOC of the power battery at the current moment according to the validity of the single cell voltage of the power battery at the current moment and the validity of the current of the power battery at the current moment further includes:

[0029] If the single cell voltage of the power battery at the current moment is valid, then determine whether the current of the power battery at the current moment is valid;

[0030] If the current of the power battery at the current moment is valid, then the SOC of the power battery at the current moment is estimated based on the current of the power battery at the current moment using the ampere-hour integration algorithm and the dynamic voltage correction algorithm;

[0031] If the current of the power battery at the current moment is invalid, the estimated current of the power battery at the current moment is obtained according to the battery equivalent circuit model, and based on the estimated current, the SOC of the power battery at the current moment is estimated using the ampere-hour integration algorithm and the dynamic voltage correction algorithm.

[0032] Optionally, when the BMS of the vehicle is powered on, the temperature of the power battery at the current moment is determined by the following steps:

[0033] When the vehicle's BMS is powered on, determine whether the current power battery temperature is valid;

[0034] If the temperature of the power battery at the current moment is invalid, determine whether the temperature of the power battery stored when the BMS was powered off last time is valid;

[0035] If the temperature of the power battery stored when the BMS was powered off last time is valid, the temperature of the power battery stored when the BMS was powered off last time is determined as the temperature of the power battery at the current moment;

[0036] If the temperature of the power battery stored when the BMS was powered off last time is invalid, the preset temperature is determined as the temperature of the power battery at the current moment.

[0037] Optionally, when the BMS of the vehicle is running, the temperature of the power battery at the current moment is determined by the following steps:

[0038] When the vehicle's BMS is running, determine whether the temperature of the power battery at the current moment is valid;

[0039] If the temperature of the power battery at the current moment is invalid, the temperature of the power battery at the previous moment is used as the temperature of the power battery at the current moment.

[0040] In a second aspect, a device for determining the SOC of a power battery is provided, the device comprising:

[0041] The first SOC determination module determines the SOC of the power battery at the current moment according to a failure combination of the temperature of the power battery at the current moment, the validity of the single cell voltage of the power battery at the current moment, and the validity of the SOC of the power battery stored when the BMS was powered off last time, if the SOC calibration condition of the power battery is met at the time of power-on of the vehicle; if the SOC calibration condition of the power battery is not met, determines the SOC of the power battery at the current moment according to the validity of the power battery temperature stored when the BMS was powered off last time;

[0042] The second SOC determination module determines the SOC of the power battery at a current moment according to the validity of the single cell voltage of the power battery at a current moment and the validity of the current of the power battery at a current moment when the BMS of the vehicle is running.

[0043] In the third aspect, an embodiment of the present application also provides an electronic device, comprising: a processor, a memory and a bus, the memory storing machine-readable instructions executable by the processor, when the electronic device is running, the processor and the memory communicate through the bus, and when the machine-readable instructions are executed by the processor, the steps of any possible implementation of the first aspect or the first aspect of the first aspect are performed.

[0044] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of any possible implementation of the above-mentioned first aspect, or the first aspect of the first aspect are executed.

[0045] In a fifth aspect, an embodiment of the present application further provides a vehicle, including an on-board controller, a power battery and a BMS; the on-board controller is configured as follows:

[0046] At the moment when the BMS of the vehicle is powered on, if the SOC calibration condition of the power battery is met, the SOC of the power battery at the current moment is determined according to the failure combination of the temperature of the power battery at the current moment, the validity of the single cell voltage of the power battery at the current moment, and the validity of the SOC of the power battery stored when the BMS was powered off last time; if the SOC calibration condition of the power battery is not met, the SOC of the power battery at the current moment is determined according to the validity of the power battery temperature stored when the BMS was powered off last time;

[0047] When the BMS of the vehicle is running, the SOC of the power battery at the current moment is determined according to the validity of the single cell voltage of the power battery at the current moment and the validity of the current of the power battery at the current moment.

[0048] According to the method and device for determining the SOC of the power battery in the embodiment of the present application, the influence of failures such as current, voltage and temperature on SOC estimation can be fully considered, and the SOC can be calculated under different failure combinations. In this way, the abnormality of SOC can be effectively reduced and the accuracy of SOC estimation can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0050] Figure 1 A flow chart showing a method for determining the SOC of a power battery provided in an embodiment of the present application is shown;

[0051] Figure 2 A flowchart showing the steps of determining the SOC of the power battery at the current moment when the BMS provided by the embodiment of the present application is powered on;

[0052] Figure 3 A flowchart showing the steps of determining the temperature of the power battery when the BMS is powered on provided by an exemplary embodiment of the present application;

[0053] Figure 4 A circuit diagram showing a first-order RC equivalent circuit model provided by an exemplary embodiment of the present application;

[0054] Figure 5 A flowchart showing the steps of determining the SOC of the power battery at the current moment when the BMS is running provided by an exemplary embodiment of the present application;

[0055] Figure 6 A schematic diagram showing the structure of a device for determining the SOC of a power battery provided by an exemplary embodiment of the present application is shown;

[0056] Figure 7 A schematic structural diagram of an electronic device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0057] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application usually described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, each other embodiment obtained by those skilled in the art without making creative work belongs to the scope of protection of the present application.

[0058] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0059] The following method or device of the embodiment of the present application can be applied to any scenario where the SOC of the power battery of the vehicle needs to be estimated, for example, it can be applied to the vehicle control terminal, server, etc. The embodiment of the present application does not limit the specific application scenario, and any solution that uses the method provided in the embodiment of the present application to estimate the SOC of the power battery of the vehicle is within the protection scope of the present application.

[0060] It should be noted that the term "comprising" will be used in the embodiments of the present application to indicate the existence of the features declared thereafter, but does not exclude the addition of other features.

[0061] With the increasing global energy shortage and environmental pollution, the development of new energy vehicles has attracted more and more attention. As the energy carrier of new energy vehicles, the status monitoring of power batteries is particularly important. The battery management system (BMS) detects the status of each single battery in the power battery pack and adjusts the corresponding control strategy of the power battery system according to their status, thereby realizing the charge and discharge management of the power battery system to ensure its safe and stable operation. At present, the state of charge SOC estimation of the power battery is one of the cores of BMS. The accurate estimation of SOC plays an important role in optimizing the energy management of the whole vehicle, improving the capacity and energy utilization of the power battery, preventing the power battery from overcharging and over-discharging, and ensuring the safety and long life of the power battery during use. It can also bring protection for the driving safety of the driver.

[0062] However, SOC cannot be directly measured in BMS, and its size can only be estimated indirectly through the direct measurement parameters of the battery. At present, the most commonly used SOC estimation method is the basic ampere-hour integration algorithm combined with the voltage correction algorithm. Among them, the basic ampere-hour integration algorithm estimates the SOC of the power battery by calculating the cumulative ampere-hours of charge and discharge of the battery; the voltage correction algorithm includes but is not limited to open circuit voltage correction, dynamic terminal voltage correction and Kalman filter algorithm. However, no matter which SOC estimation algorithm is used, most of them involve the two basic measurements of BMS, current and voltage. At the same time, considering that the battery characteristic parameters including capacity, internal resistance and other parameters will change with temperature, any abnormal failure of any of the BMS measurement quantities (for example, current, voltage, temperature, etc.) will cause SOC to jump, remain unchanged for a long time, and have excessive deviations, thereby affecting the SOC estimation and further affecting the user experience.

[0063] In response to at least one of the above-mentioned problems, an embodiment of the present application provides a method and a device for determining the SOC of a power battery. This solution can fully consider the impact of failures such as current, voltage and temperature on SOC estimation, and calculate the SOC under different failure combinations. In this way, it is possible to effectively reduce the occurrence of SOC abnormalities and improve the accuracy of SOC estimation.

[0064] To facilitate understanding of this embodiment, a method for determining the SOC of a power battery disclosed in an embodiment of the present application is first introduced in detail.

[0065] Figure 1 A flowchart showing a method for determining the power battery SOC provided by an exemplary embodiment of the present application is shown in FIG. Figure 1 Exemplarily, the method for determining the power battery SOC may be executed by an onboard controller of a vehicle, and the method for determining the power battery SOC specifically includes:

[0066] The vehicle's BMS is powered on. Here, BMS refers to the vehicle's battery management system. The battery management system is mainly used to detect the status of each single cell in the power battery pack and adjust the corresponding control strategy of the power battery according to the status of each single cell, so as to realize the charge and discharge management of the power battery system to ensure its safe and stable operation.

[0067] Step S110: When the BMS of the vehicle is powered on, determine whether the SOC calibration condition of the power battery is met.

[0068] As an example, the SOC calibration condition of the power battery may be the interval time between the power-on time of the current BMS and the power-off time of the previous BMS. Here, satisfying the SOC calibration condition of the power battery means that the interval time between the power-on time of the current BMS and the power-off time of the previous BMS is greater than the preset time; not satisfying the SOC calibration condition of the power battery means that the interval time between the power-on time of the current BMS and the power-off time of the previous BMS is not greater than the preset time. Here, the preset time may be a fixed time pre-set according to the battery characteristics, for example, 30 minutes, etc.

[0069] In addition, it should be understood that the SOC calibration condition of the power battery can also be set according to actual scenarios or needs in addition to other conditions of whether the above-mentioned interval time meets the preset time, and this application does not make any limitation here.

[0070] Step S120: If the SOC calibration condition of the power battery is met, the SOC of the power battery at the current moment is determined according to a failure combination of the temperature of the power battery at the current moment, the validity of the single cell voltage of the power battery at the current moment, and the validity of the SOC of the power battery stored when the BMS was powered off last time.

[0071] Figure 2 A flowchart showing the steps of determining the SOC of the power battery at the current moment when the BMS is powered on provided by an exemplary embodiment of the present application.

[0072] like Figure 2 As shown, as an example, regarding step S120, in specific implementation, the following steps may be included:

[0073] Step S201: If the SOC calibration condition of the power battery is met, determine whether the single cell voltage of the power battery at the current moment is valid.

[0074] Here, it should be noted that the power battery is composed of a plurality of single cells stacked in a certain manner, and each single cell itself is an independent individual. The single cell voltage refers to the voltage of each single cell. Specifically, the voltage of each single cell of the power battery can be obtained under the condition that the SOC calibration of the power battery is satisfied. As an example, whether the single cell voltage is valid refers to determining whether the single cell voltage is within the predetermined allowable variation range of the single cell voltage. If the detected single cell voltage of the power battery at the current moment is within the predetermined variation range, the single cell voltage is determined to be valid. If the detected single cell voltage of the power battery at the current moment is not within the predetermined variation range, the single cell voltage is determined to be invalid. For example, assuming that the single cell voltage range of the power battery is 2V to 4V, and the allowable variation range of the single cell voltage when the BMS is powered on is 2±0.01 to 4±0.01V, therefore, when the single cell voltage does not exceed 4.01V and is not less than 1.99V when the BMS is powered on, the single cell voltage when the BMS is powered on can be considered valid; otherwise, the single cell voltage when the BMS is powered on is considered invalid.

[0075] In addition, it should be understood that the determination condition of whether the cell voltage is valid can also be other conditions other than the above-mentioned predetermined variation range set according to the actual scenario or demand, for example, the failure of cell voltage collection, where collection failure refers to the situation where the collected cell voltage is not successfully received. If the cell voltage of the power battery at the current moment is successfully received, the cell voltage is deemed valid, and if the cell voltage of the power battery at the current moment is not successfully received, the cell voltage is deemed invalid. In addition, multiple conditions can also be superimposed and used. For example, after successfully receiving the cell voltage of the power battery at the current moment, it can be further determined whether the cell voltage is within the predetermined variation range of the cell voltage. If it is within the predetermined variation range, it is considered that the cell voltage is valid when the BMS is powered on. Otherwise, it is considered that the cell voltage is invalid when the BMS is powered on. The above-mentioned setting method can be flexibly set, and this application does not make any limitation here.

[0076] Step S202: If the cell voltage is valid, determine whether the cell voltage is in a non-plateau region of a discharge characteristic curve.

[0077] Here, it should be noted that when a battery is discharged, its operating voltage always changes with the passage of time. The curve drawn by the operating voltage and discharge time or capacity of the battery is called the discharge characteristic curve. In other words, the discharge characteristic curve can be a curve of the terminal voltage of the battery changing with time. According to the discharge characteristic curve, the voltage of the battery changes rapidly in the initial stage and the end stage of discharge. This section of the curve is called the non-platform area of ​​the battery. The voltage changes slowly in the middle stage. This section of the curve becomes the platform area of ​​the battery.

[0078] Step S203: If the cell voltage is in the non-platform region of the discharge characteristic curve, the SOC of the power battery at the current moment is determined by consulting the SOC-OCV curve according to the cell voltage and the temperature of the power battery at the current moment.

[0079] Here, it should be noted that the SOC-OCV curve is a curve that characterizes the chemical properties of a battery, OCV is the open circuit voltage of the battery, SOC is the state of charge of the battery, and the SOC-OCV curve of the battery is different at different temperatures.

[0080] Here, the SOC-OCV curve can mostly be obtained through an open circuit voltage test. If the single cell voltage is in the non-platform area of ​​the discharge characteristic curve, when the single cell voltage and temperature of the power battery are known, the SOC in the SOC-OCV curve of the power battery at the temperature and the single cell voltage (i.e., the open circuit voltage OCV) can be consulted to obtain the SOC of the power battery at the current moment.

[0081] The temperature of the power battery at the current moment can be determined by:

[0082] Figure 3 A flowchart showing the steps of determining the temperature of the power battery when the BMS is powered on provided by an exemplary embodiment of the present application. Figure 3 As shown, as an example, when the vehicle's BMS is powered on, the temperature of the power battery at the current moment can be determined by the following steps:

[0083] Step S301: When the BMS of the vehicle is powered on, determine whether the temperature of the power battery at the current moment is valid.

[0084] Here, it should be noted that, in an example of the present application, a pre-set effective temperature range can be determined. If the temperature of the power battery detected by the sensor at the current moment is within the effective range, the temperature of the power battery at the current moment is determined to be valid; if the temperature of the power battery detected by the sensor at the current moment is not within the effective range, the temperature of the power battery at the current moment is determined to be invalid.

[0085] Step S302: If the temperature of the power battery at the current moment is invalid, determine whether the temperature of the power battery stored when the BMS was powered off last time is valid.

[0086] Here, it should be noted that, similar to determining whether the stored SOC is valid, the BMS stores the temperature of the power battery in a predetermined storage space, wherein the temperature stored in the predetermined storage space can be determined to be valid by determining whether the temperature is within the valid temperature range. If the temperature of the power battery stored when the BMS was powered off last time is within the valid range, it is determined that the temperature of the power battery stored when the BMS was powered off last time is valid; if the temperature of the power battery stored when the BMS was powered off last time is not within the valid range, it is determined that the temperature of the power battery stored when the BMS was powered off last time is invalid.

[0087] Step S303: If the temperature of the power battery stored when the BMS was powered off last time is valid, the temperature of the power battery stored when the BMS was powered off last time is determined as the temperature of the power battery at the current moment.

[0088] In step S304 : if the temperature of the power battery stored when the BMS was powered off last time is invalid, the preset temperature is determined as the temperature of the power battery at the current moment.

[0089] Here, it should be noted that the preset temperature may be a pre-set temperature that conforms to the actual situation. For example, the preset temperature may be set to 25 degrees Celsius.

[0090] In addition, correspondingly, in step S305: if the temperature of the power battery at the current moment is valid, the valid temperature may be determined as the temperature of the power battery at the current moment.

[0091] Return to reference Figure 2 , step S204: if the single cell voltage is not in the non-platform area of ​​the discharge characteristic curve, it is determined whether the SOC of the power battery stored when the BMS was powered off last time is valid.

[0092] Here, it should be noted that, in order to prevent the BMS from abnormally powering off, the SOC is usually saved in a predetermined storage space, for example, the SOC is saved in NVM, etc. If the cell voltage is not in the non-platform area of ​​the discharge characteristic curve, the SOC of the power battery stored when the BMS was powered off last time can be read from the corresponding predetermined storage space to determine whether it is valid. The criteria for determining whether the SOC is valid are similar to those described above. For example, there is a preset valid interval for the SOC. If the SOC of the power battery stored when the BMS was powered off last time is within the preset valid interval, the SOC is determined to be valid. On the contrary, if the SOC of the power battery stored when the BMS was powered off last time is not within the preset valid interval, the SOC is determined to be invalid. In addition, other SOC validity conditions can also be set according to actual conditions, and this application does not make any restrictions here.

[0093] Step S205: If the SOC of the power battery stored when the BMS was powered off last time is valid, the SOC of the power battery stored when the BMS was powered off last time is determined as the SOC of the power battery at the current moment.

[0094] Specifically, if the SOC of the power battery stored when the BMS was powered off last time is valid, the SOC of the power battery stored when the BMS was powered off last time is read from the predetermined storage space, and the stored SOC is determined as the SOC of the power battery at the current moment.

[0095] Step S206: If the SOC of the power battery stored when the BMS was powered off last time is invalid, the SOC of the power battery at the current moment is determined by consulting the SOC-OCV curve according to the cell voltage and the temperature of the power battery at the current moment.

[0096] Refer again Figure 2 , step S130: if the power battery SOC calibration condition is not met, the SOC of the power battery at the current moment is determined according to the validity of the power battery temperature stored when the BMS was powered off last time. In the specific implementation, the following steps may also be included:

[0097] Step S207: If the SOC calibration condition of the power battery is not met and the cell voltage is invalid, determine whether the SOC of the power battery stored when the BMS was powered off last time is valid.

[0098] Here, it should be noted that the SOC calibration conditions of the power battery and the method for determining whether the SOC of the power battery stored when the BMS was powered off last time is valid have been described in detail above and will not be repeated here.

[0099] Step S208: If the SOC of the power battery stored when the BMS was powered off last time is valid, the SOC of the power battery stored when the BMS was powered off last time is determined as the SOC of the power battery at the current moment.

[0100] Step S209: If the SOC of the power battery stored when the BMS was powered off last time is invalid, the open circuit voltage of the power battery at the time when the BMS is powered on is calculated according to the battery equivalent circuit model, and the SOC of the power battery at the current moment is determined by referring to the SOC-OCV curve based on the open circuit voltage and the temperature of the power battery at the current moment.

[0101] As an example, regarding step S209, in specific implementation, the terminal voltage and polarization voltage during the last BMS power-off process can be first obtained; then, the difference between the terminal voltage and the polarization voltage is determined as the open circuit voltage of the power battery at the time of BMS power-on. Here, the battery equivalent circuit model is taken as a first-order RC equivalent circuit model as an example to illustrate the process of calculating the SOC of the power battery at the current moment.

[0102] Specifically, Figure 4 A circuit diagram showing a first-order RC equivalent circuit model provided by an exemplary embodiment of the present application; a first-order RC equivalent circuit model of a power battery is shown in FIG. Figure 4 As shown, Rp and Cp are polarization internal resistance and polarization capacitance respectively, R0 is ohmic internal resistance, Voc is open circuit voltage, and Uk is battery terminal voltage. Rp and Cp can be obtained by offline fitting of pulse test data. During the BMS power-off process, the battery pack current is 0A, so the battery terminal voltage u during the BMS power-off process is k The calculation formula (1) is:

[0103] u k =OCV+U p (1)

[0104] Among them, OCV is the open circuit voltage during the BMS power-on process, U p is the polarization voltage, where the polarization voltage U p It can be determined by the following calculation formula (2):

[0105]

[0106] Among them, U p (0) is the polarization voltage value when the BMS was powered off last time, U p (1) is the polarization voltage at the moment of BMS power-on, and ΔT is the interval time between the moment of BMS power-on and the moment of BMS last power-off.

[0107] Accordingly, the open circuit voltage OCV at the time of BMS power-on can be determined by the following calculation formula (3):

[0108] OCV=u k -U p (3)

[0109] After obtaining the open circuit voltage OCV at the time of BMS power-on, the SOC of the power battery at the current moment can be determined by referring to the SOC-OCV curve according to the open circuit voltage and the temperature of the power battery at the current moment in the aforementioned manner.

[0110] Return to reference Figure 1 , the method for determining the power battery SOC also includes the step of determining the SOC of the power battery at the current moment when the BMS of the vehicle is running:

[0111] Specifically, the BMS of the vehicle is running. In step S140 , when the BMS of the vehicle is running, the SOC of the power battery at the current moment is determined according to the validity of the single cell voltage of the power battery at the current moment and the validity of the current of the power battery at the current moment.

[0112] Combine the following Figure 5 The following describes in detail how to determine the SOC of the power battery at the current moment when the BMS is running. Figure 5 A flowchart showing the steps of determining the SOC of the power battery at the current moment when the BMS is running provided by an exemplary embodiment of the present application. Figure 5 As shown, as an example, regarding step S140, during specific implementation, the following steps may be included:

[0113] Step S501: Determine whether the single cell voltage of the power battery at the current moment is valid.

[0114] In specific implementation, whether the single cell voltage of the power battery at the current moment is valid can be determined in the manner described above. The specific manner has been mentioned above and will not be repeated here.

[0115] Step S502: If the single cell voltage of the power battery at the current moment is invalid, determine whether the current of the power battery at the current moment is valid.

[0116] Here, it can be determined whether the acquired current is within the predetermined current range. If the acquired current is within the predetermined current range, it is determined that the current of the power battery at the current moment is valid; if the acquired current is no longer within the predetermined current range, it is determined that the current of the power battery at the current moment is invalid.

[0117] Step S503: If the current of the power battery at the current moment is invalid, the SOC of the power battery at the previous moment is used as the SOC of the power battery at the current moment.

[0118] Step S504: If the current of the power battery at the current moment is valid, then based on the current of the power battery at the current moment, the SOC of the power battery at the current moment is estimated using an ampere-hour integration algorithm and a dynamic voltage correction algorithm.

[0119] Here, it should be noted that the SOC estimation method is a basic ampere-hour integration algorithm combined with a dynamic voltage correction algorithm, wherein the basic ampere-hour integration algorithm estimates the SOC of the power battery by calculating the cumulative ampere-hours of charge and discharge of the battery; the above-mentioned existing method can be used to use the ampere-hour integration algorithm combined with the dynamic voltage correction algorithm based on the effective current of the power battery at the current moment to estimate the SOC of the power battery at the current moment. Here, the dynamic voltage correction algorithm includes but is not limited to open circuit voltage correction, dynamic terminal voltage correction, and Kalman filter algorithm.

[0120] On the other hand, if the single cell voltage of the power battery at the current moment is valid, then in step S502: continue to determine whether the current of the power battery at the current moment is valid.

[0121] Step S505: If the current of the power battery at the current moment is valid, then based on the current of the power battery at the current moment, the SOC of the power battery at the current moment is estimated using an ampere-hour integration algorithm and a dynamic voltage correction algorithm.

[0122] Step S506: If the current of the power battery at the current moment is invalid, the estimated current of the power battery at the current moment is obtained according to the battery equivalent circuit model, and based on the estimated current, the SOC of the power battery at the current moment is estimated using the ampere-hour integration algorithm and the dynamic voltage correction algorithm.

[0123] Here, taking the battery equivalent circuit model as a first-order RC equivalent circuit model as an example, the process of calculating the SOC of the power battery at the current moment is explained.

[0124] Specifically, the first-order RC equivalent circuit model of the power battery is as follows: Figure 4 As shown, Rp and Cp are polarization internal resistance and polarization capacitance respectively, R0 is ohmic internal resistance, u k is the battery terminal voltage. Rp and Cp can be obtained by offline fitting of pulse test data. The charge / discharge state current value of the power battery can be derived according to the equivalent circuit model formula. The calculation method of the estimated current is explained by the first-order RC equivalent circuit model (4) as follows:

[0125] Battery terminal voltage u k The calculation formula is as follows:

[0126]

[0127] Among them, U p (k) is the polarization voltage at the current BMS operation time.

[0128] After derivation, the estimated current i at the current BMS operation time is k The calculation formula (5) is:

[0129]

[0130] In this way, the estimated current of the power battery at the current moment can be obtained according to the above-mentioned battery equivalent circuit model, and the estimated current can be used as the current current of the power battery, and the SOC of the power battery at the current moment can be estimated using the ampere-hour integration algorithm and the dynamic voltage correction algorithm.

[0131] In view of the accuracy of the above method, in actual testing, the CLTC test condition of lithium iron phosphate battery was used as an example to conduct the test, and the current value was calculated by Simulink simulation according to the above formula, and the SOC value was calculated using the calculated current value. The simulation results show that the current value calculated according to this application is consistent with the current trend collected by the real current collector, and the maximum deviation of the calculated SOC value is less than 5%. This test verifies that in the case of invalid current, the solution provided by this application can effectively approach the real value of SOC.

[0132] In summary, according to the method for determining the SOC of a power battery of the exemplary embodiment of the present application, the influence of failures such as current, voltage and temperature on SOC estimation can be fully considered, and the SOC can be calculated under different failure combinations. In this way, the abnormality of SOC can be effectively reduced and the accuracy of SOC estimation can be improved.

[0133] Based on the same application concept, an embodiment of the present application also provides a device for determining the SOC of a power battery corresponding to the method provided in the above embodiment. Since the principle of solving the problem by the device in the embodiment of the present application is similar to a method for determining the SOC of a power battery in the above embodiment of the present application, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be repeated.

[0134] Figure 6 The following is a schematic diagram of a device for determining the SOC of a power battery provided by an exemplary embodiment of the present application. Figure 6 As shown, the power battery SOC determination device includes:

[0135] The first SOC determination module 610 determines the SOC of the power battery at the current moment according to a failure combination of the temperature of the power battery at the current moment, the validity of the single cell voltage of the power battery at the current moment, and the validity of the SOC of the power battery stored when the BMS was powered off last time, if the SOC calibration condition of the power battery is met at the time when the BMS is powered on; if the SOC calibration condition of the power battery is not met, determines the SOC of the power battery at the current moment according to the validity of the power battery temperature stored when the BMS was powered off last time;

[0136] The second SOC determination module 620 determines the SOC of the power battery at a current moment according to the validity of the single cell voltage and the validity of the current of the power battery at a current moment when the BMS of the vehicle is running.

[0137] Optionally, the SOC calibration condition of the power battery is the interval time between the power-on time of the current BMS and the power-off time of the last BMS;

[0138] Meeting the SOC calibration condition of the power battery means that the interval between the power-on time of the current BMS and the power-off time of the last BMS is greater than the preset time;

[0139] Failure to meet the SOC calibration condition of the power battery means that the interval between the power-on time of the current BMS and the power-off time of the previous BMS is not greater than the preset time.

[0140] Optionally, the first SOC determination module 610 is specifically configured to:

[0141] If the SOC calibration condition of the power battery is met, determine whether the single cell voltage of the power battery at the current moment is valid;

[0142] If the cell voltage is valid, determining whether the cell voltage is in a non-plateau region of a discharge characteristic curve;

[0143] If the cell voltage is in the non-platform region of the discharge characteristic curve, the SOC of the power battery at the current moment is determined by referring to the SOC-OCV curve according to the cell voltage and the temperature of the power battery at the current moment;

[0144] If the single cell voltage is not in the non-platform area of ​​the discharge characteristic curve, it is determined whether the SOC of the power battery stored when the BMS was powered off last time is valid; if the SOC of the power battery stored when the BMS was powered off last time is valid, the SOC of the power battery stored when the BMS was powered off last time is determined as the SOC of the power battery at the current moment; if the SOC of the power battery stored when the BMS was powered off last time is invalid, the SOC of the power battery at the current moment is determined by referring to the SOC-OCV curve based on the single cell voltage and the temperature of the power battery at the current moment.

[0145] Optionally, the first SOC determination module 610 is specifically configured to:

[0146] If the SOC calibration condition of the power battery is not met and the cell voltage is invalid, determining whether the SOC of the power battery stored when the BMS was powered off last time is valid;

[0147] If the SOC of the power battery stored when the BMS was powered off last time is valid, the SOC of the power battery stored when the BMS was powered off last time is determined as the SOC of the power battery at the current moment;

[0148] If the SOC of the power battery stored when the BMS was powered off last time is invalid, the open circuit voltage of the power battery at the time when the BMS is powered on is calculated according to the battery equivalent circuit model, and the SOC of the power battery at the current moment is determined by referring to the SOC-OCV curve based on the open circuit voltage and the temperature of the power battery at the current moment.

[0149] Optionally, the first SOC determination module 610 is specifically configured to:

[0150] Get the terminal voltage and polarization voltage during the last BMS power-off process;

[0151] The difference between the terminal voltage and the polarization voltage is determined as the open circuit voltage of the power battery when the BMS is powered on.

[0152] Optionally, the second SOC determination module 620 is specifically used to: determine whether the single cell voltage of the power battery at the current moment is valid;

[0153] If the single cell voltage of the power battery at the current moment is invalid, determine whether the current of the power battery at the current moment is valid;

[0154] If the current of the power battery at the current moment is invalid, the SOC of the power battery at the previous moment is used as the SOC of the power battery at the current moment;

[0155] If the current of the power battery at the current moment is valid, the SOC of the power battery at the current moment is estimated based on the current of the power battery at the current moment using the ampere-hour integration algorithm and the dynamic voltage correction algorithm.

[0156] Optionally, the second SOC determination module 620 is specifically configured to: if the single cell voltage of the power battery at the current moment is valid, determine whether the current of the power battery at the current moment is valid;

[0157] If the current of the power battery at the current moment is valid, then the SOC of the power battery at the current moment is estimated based on the current of the power battery at the current moment using the ampere-hour integration algorithm and the dynamic voltage correction algorithm;

[0158] If the current of the power battery at the current moment is invalid, the estimated current of the power battery at the current moment is obtained according to the battery equivalent circuit model, and based on the estimated current, the SOC of the power battery at the current moment is estimated using the ampere-hour integration algorithm and the dynamic voltage correction algorithm.

[0159] The control device also includes:

[0160] Temperature determination unit ( Figure 6 Not shown): The temperature determination unit is used to:

[0161] When the vehicle's BMS is powered on, the temperature of the power battery at the current moment is determined through the following steps:

[0162] When the vehicle's BMS is powered on, determine whether the current power battery temperature is valid;

[0163] If the temperature of the power battery at the current moment is invalid, determine whether the temperature of the power battery stored when the BMS was powered off last time is valid;

[0164] If the temperature of the power battery stored when the BMS was powered off last time is valid, the temperature of the power battery stored when the BMS was powered off last time is determined as the temperature of the power battery at the current moment;

[0165] If the temperature of the power battery stored when the BMS was powered off last time is invalid, the preset temperature is determined as the temperature of the power battery at the current moment.

[0166] Optionally, the temperature determination unit is used to determine the temperature of the power battery at the current moment by the following steps when the BMS of the vehicle is running:

[0167] When the vehicle's BMS is running, determine whether the temperature of the power battery at the current moment is valid;

[0168] If the temperature of the power battery at the current moment is invalid, the temperature of the power battery at the previous moment is used as the temperature of the power battery at the current moment.

[0169] See also Figure 7 , Figure 7 The structural diagram of the electronic device provided by the exemplary embodiment of the present application. Figure 7 As shown, the electronic device 900 includes a processor 910 , a memory 920 , and a bus 930 .

[0170] The memory 920 stores machine-readable instructions executable by the processor 910. When the electronic device 900 is running, the processor 910 communicates with the memory 920 via the bus 930. When the machine-readable instructions are executed by the processor 910, the steps of the method for determining the power battery SOC in any of the above embodiments may be performed, which are specifically as follows:

[0171] At the moment when the BMS of the vehicle is powered on, if the SOC calibration condition of the power battery is met, the SOC of the power battery at the current moment is determined according to the failure combination of the temperature of the power battery at the current moment, the validity of the single cell voltage of the power battery at the current moment, and the validity of the SOC of the power battery stored when the BMS was powered off last time; if the SOC calibration condition of the power battery is not met, the SOC of the power battery at the current moment is determined according to the validity of the power battery temperature stored when the BMS was powered off last time;

[0172] When the BMS of the vehicle is running, the SOC of the power battery at the current moment is determined according to the validity of the single cell voltage of the power battery at the current moment and the validity of the current of the power battery at the current moment.

[0173] An embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for controlling the in-vehicle air conditioner in the above-mentioned method embodiment can be executed. The specific implementation method can be found in the method embodiment, which will not be repeated here.

[0174] Specifically, the storage medium can be a general storage medium, such as a mobile disk, a hard disk, etc. When the computer program on the storage medium is run, the above-mentioned method for controlling the in-vehicle air conditioner can be executed.

[0175] The embodiment of the present application also provides a vehicle, including an on-board controller, a power battery and a BMS; the on-board controller is configured to: when the BMS of the vehicle is powered on, if the SOC calibration condition of the power battery is met, the SOC of the power battery at the current moment is determined according to the failure combination of the temperature of the power battery at the current moment, the validity of the single cell voltage of the power battery at the current moment, and the validity of the SOC of the power battery stored when the BMS was powered off last time; if the SOC calibration condition of the power battery is not met, the SOC of the power battery at the current moment is determined according to the validity of the power battery temperature stored when the BMS was powered off last time; when the BMS of the vehicle is running, the SOC of the power battery at the current moment is determined according to the validity of the single cell voltage of the power battery at the current moment and the validity of the current of the power battery at the current moment. The specific implementation method can be found in the method embodiment, which will not be repeated here.

[0176] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working process of the system and device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. In the several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0177] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0178] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0179] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc., various media that can store program codes.

[0180] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for determining the SOC of a power battery, characterized in that: The determination method comprises: At the moment when the BMS of the vehicle is powered on, if the SOC calibration condition of the power battery is met, the SOC of the power battery at the current moment is determined according to the failure combination of the temperature of the power battery at the current moment, the validity of the single cell voltage of the power battery at the current moment, and the validity of the SOC of the power battery stored when the BMS was powered off last time; if the SOC calibration condition of the power battery is not met, the SOC of the power battery at the current moment is determined according to the validity of the power battery temperature stored when the BMS was powered off last time; When the BMS of the vehicle is running, the SOC of the power battery at the current moment is determined according to the validity of the single cell voltage of the power battery at the current moment and the validity of the current of the power battery at the current moment.

2. The determination method according to claim 1, characterized in that: The SOC calibration condition of the power battery is the interval between the power-on time of the current BMS and the power-off time of the last BMS; Meeting the SOC calibration condition of the power battery means that the interval between the power-on time of the current BMS and the power-off time of the last BMS is greater than the preset time; Failure to meet the SOC calibration condition of the power battery means that the interval between the power-on time of the current BMS and the power-off time of the previous BMS is not greater than the preset time.

3. The determination method according to claim 1, characterized in that: If the SOC calibration condition of the power battery is met, the step of determining the SOC of the power battery at the current moment according to a failure combination of the temperature of the power battery at the current moment, the validity of the single cell voltage of the power battery at the current moment, and the validity of the SOC of the power battery stored when the BMS was powered off last time includes: If the SOC calibration condition of the power battery is met, determine whether the single cell voltage of the power battery at the current moment is valid; If the cell voltage is valid, determining whether the cell voltage is in a non-plateau region of a discharge characteristic curve; If the cell voltage is in the non-platform region of the discharge characteristic curve, the SOC of the power battery at the current moment is determined by referring to the SOC-OCV curve according to the cell voltage and the temperature of the power battery at the current moment; If the single cell voltage is not in the non-platform area of ​​the discharge characteristic curve, it is determined whether the SOC of the power battery stored when the BMS was powered off last time is valid; if the SOC of the power battery stored when the BMS was powered off last time is valid, the SOC of the power battery stored when the BMS was powered off last time is determined as the SOC of the power battery at the current moment; if the SOC of the power battery stored when the BMS was powered off last time is invalid, the SOC of the power battery at the current moment is determined by referring to the SOC-OCV curve based on the single cell voltage and the temperature of the power battery at the current moment.

4. The determination method according to claim 1, characterized in that: If the power battery SOC calibration condition is not met, the step of determining the SOC of the power battery at the current moment according to the validity of the power battery temperature stored when the BMS was powered off last time includes: If the SOC calibration condition of the power battery is not met and the cell voltage is invalid, determining whether the SOC of the power battery stored when the BMS was powered off last time is valid; If the SOC of the power battery stored when the BMS was powered off last time is valid, the SOC of the power battery stored when the BMS was powered off last time is determined as the SOC of the power battery at the current moment; If the SOC of the power battery stored when the BMS was powered off last time is invalid, the open circuit voltage of the power battery at the time when the BMS is powered on is calculated according to the battery equivalent circuit model, and the SOC of the power battery at the current moment is determined by referring to the SOC-OCV curve based on the open circuit voltage and the temperature of the power battery at the current moment.

5. The determination method according to claim 4, characterized in that: The step of calculating the open circuit voltage of the power battery at the time when the BMS is powered on according to the battery equivalent circuit model includes: Get the terminal voltage and polarization voltage during the last BMS power-off process; The difference between the terminal voltage and the polarization voltage is determined as the open circuit voltage of the power battery when the BMS is powered on.

6. The determination method according to claim 1, characterized in that: The step of determining the SOC of the power battery at the current moment according to the validity of the single cell voltage of the power battery at the current moment and the validity of the current of the power battery at the current moment comprises: Determine whether the single cell voltage of the power battery is valid at the current moment; If the single cell voltage of the power battery at the current moment is invalid, determine whether the current of the power battery at the current moment is valid; If the current of the power battery at the current moment is invalid, the SOC of the power battery at the previous moment is used as the SOC of the power battery at the current moment; If the current of the power battery at the current moment is valid, the SOC of the power battery at the current moment is estimated based on the current of the power battery at the current moment using the ampere-hour integration algorithm and the dynamic voltage correction algorithm.

7. The determination method according to claim 6, characterized in that: The step of determining the SOC of the power battery at the current moment according to the validity of the single cell voltage of the power battery at the current moment and the validity of the current of the power battery at the current moment also includes: If the single cell voltage of the power battery at the current moment is valid, then determine whether the current of the power battery at the current moment is valid; If the current of the power battery at the current moment is valid, then the SOC of the power battery at the current moment is estimated based on the current of the power battery at the current moment using the ampere-hour integration algorithm and the dynamic voltage correction algorithm; If the current of the power battery at the current moment is invalid, the estimated current of the power battery at the current moment is obtained according to the battery equivalent circuit model, and based on the estimated current, the SOC of the power battery at the current moment is estimated using the ampere-hour integration algorithm and the dynamic voltage correction algorithm.

8. The determination method according to claim 1, characterized in that: When the vehicle's BMS is powered on, the temperature of the power battery at the current moment is determined through the following steps: When the vehicle's BMS is powered on, determine whether the current power battery temperature is valid; If the temperature of the power battery at the current moment is invalid, determine whether the temperature of the power battery stored when the BMS was powered off last time is valid; If the temperature of the power battery stored when the BMS was powered off last time is valid, the temperature of the power battery stored when the BMS was powered off last time is determined as the temperature of the power battery at the current moment; If the temperature of the power battery stored when the BMS was powered off last time is invalid, the preset temperature is determined as the temperature of the power battery at the current moment.

9. The determination method according to claim 1, characterized in that: When the vehicle's BMS is running, the temperature of the power battery at the current moment is determined by the following steps: When the vehicle's BMS is running, determine whether the temperature of the power battery at the current moment is valid; If the temperature of the power battery at the current moment is invalid, the temperature of the power battery at the previous moment is used as the temperature of the power battery at the current moment.

10. A device for determining the SOC of a power battery, characterized in that: The determining device comprises: The first SOC determination module determines the SOC of the power battery at the current moment according to a failure combination of the temperature of the power battery at the current moment, the validity of the single cell voltage of the power battery at the current moment, and the validity of the SOC of the power battery stored when the BMS was powered off last time, if the SOC calibration condition of the power battery is met at the time of power-on of the vehicle; if the SOC calibration condition of the power battery is not met, determines the SOC of the power battery at the current moment according to the validity of the power battery temperature stored when the BMS was powered off last time; The second SOC determination module determines the SOC of the power battery at a current moment according to the validity of the single cell voltage of the power battery at a current moment and the validity of the current of the power battery at a current moment when the BMS of the vehicle is running.

11. An electronic device, characterized in that: include: A processor, a storage medium and a bus, wherein the storage medium stores machine-readable instructions executable by the processor. When the electronic device is running, the processor communicates with the storage medium via the bus, and the processor executes the machine-readable instructions to perform the steps of the method for determining the SOC of a power battery as described in any one of claims 1 to 9.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for determining the SOC of a power battery as claimed in any one of claims 1 to 9 are executed.

13. A vehicle, characterized in that: It includes an on-board controller, a power battery and a BMS; the on-board controller is configured as follows: When the vehicle's BMS is powered on, if the power battery SOC calibration condition is met, the power battery SOC at the current moment is determined based on a failure combination of the power battery temperature at the current moment, the validity of the power battery single cell voltage at the current moment, and the validity of the power battery SOC stored when the BMS was powered off last time; If the power battery SOC calibration condition is not met, the power battery SOC at the current moment is determined based on the validity of the power battery temperature stored when the BMS was last powered off; When the BMS of the vehicle is running, the SOC of the power battery at the current moment is determined according to the validity of the single cell voltage of the power battery at the current moment and the validity of the current of the power battery at the current moment.

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