A method, device and vehicle for estimating state of charge in a power battery self-heating mode

Abstract

The present invention discloses a method, device and vehicle for estimating the state of charge of a power battery in a self-heating mode, which belongs to the technical field of power battery state of charge estimation. When receiving state of charge estimation request data, the state of charge estimation related parameters in the state of charge estimation request data and the amplitude and frequency data of the control voltage on the heating source side are respectively obtained. The state of charge estimation related parameters include: the initial state of charge of the power battery at the initial moment, the current value and battery pack capacity collected in real time by the BMS battery management system at the target moment; the corresponding current conversion coefficient is determined by the amplitude and frequency of the control voltage on the heating source side; the target state of charge of the power battery at the target moment is determined according to the state of charge estimation related parameters and the corresponding current conversion coefficient. This patent ensures the accuracy and stability of the state of charge estimation.

Description

Technical Field

[0001] The invention discloses a method, a device and a vehicle for estimating the state of charge of a power battery in a self-heating mode, and belongs to the technical field of power battery state of charge estimation. Background Art

[0002] The performance of the battery at low temperature is poor, including the battery power capability and the actual use capacity of the battery. It affects the driving performance, driving range and charging time of the whole vehicle. The battery needs to be heated to room temperature to maintain the best performance of the battery. Conventional heating methods include water circulation heating in the battery and heating with a heating plate. However, this method usually requires additional hardware settings, which in turn increases the cost of the battery pack. The battery self-heating method generates alternating current on the motor side, generates pulse charging and discharging for the battery, and uses the internal resistance of the battery to heat the entire pack. No additional hardware facilities are required, which reduces the cost of the entire pack. However, the estimation of the state of charge in the self-heating mode has encountered challenges. The traditional ampere-hour integration method fails because it cannot accurately collect the battery current. The equivalent circuit model method also fails because it cannot accurately collect the current and the collection of the single cell voltage cycle is slower than the high-frequency alternating current. The estimation of the state of charge during self-heating has become a problem. The current solution for estimating the self-heating state of charge is to accurately control the alternating current output on the motor side through an algorithm, and then calculate the battery state of charge through a stable current waveform. However, this method is highly theoretical and requires cooperation on the motor side, and the final alternating current control effect is not ideal. Summary of the invention

[0003] In view of the defects of the prior art, the present invention proposes a method, device and vehicle for estimating the state of charge in the self-heating mode of a power battery, thereby solving the problem that in the self-heating mode of the existing battery, due to the high-frequency alternating current, the current sensor at the BMS battery management system end cannot accurately collect the alternating current at this time, which brings great difficulty to the estimation of the state of charge, and the alternating current will cause the single cell voltage to fluctuate up and down.

[0004] The technical solution of the present invention is as follows:

[0005] According to a first aspect of an embodiment of the present invention, a method for estimating a state of charge of a power battery in a self-heating mode is provided, comprising:

[0006] When receiving the state of charge estimation request data, respectively obtaining the state of charge estimation related parameters in the state of charge estimation request data and the amplitude and frequency data of the control voltage on the heating source side, wherein the state of charge estimation related parameters include: the initial state of charge of the power battery at the initial moment, the real-time current value collected by the BMS battery management system at the target moment, and the battery pack capacity;

[0007] Determine the corresponding current conversion coefficient by controlling the voltage amplitude and frequency on the heating source side;

[0008] The target state of charge of the power battery at the target time is determined according to the state of charge estimation related parameters and the corresponding current conversion coefficient.

[0009] Preferably, the obtaining of the amplitude and frequency data of the control voltage on the heating source side includes: obtaining the CAN bus status and determining whether information can be transmitted:

[0010] Yes, the amplitude and frequency data of the control voltage on the heating source side are obtained through the CAN bus;

[0011] If no, proceed to the next step;

[0012] Acquire the current on the BMS battery management system side, and determine the current characteristics of the BMS battery management system side through the current on the BMS battery management system side;

[0013] Acquire the current mean and variance in a predetermined time interval according to the current on the BMS battery management system side;

[0014] The amplitude and frequency data of the control voltage on the heating source side at that moment are determined according to the current mean and variance in the predetermined time interval.

[0015] Preferably, when the CAN bus state cannot transmit information, the method further comprises:

[0016] The range interval of the BMS battery management system current is obtained, and the amplitude and frequency data of the control voltage on the heating source side at this moment are determined through the range interval of the BMS battery management system current.

[0017] Preferably, the corresponding current conversion coefficient is determined by the amplitude and frequency of the control voltage on the heating source side, including:

[0018] Determining a high-frequency AC self-heating mode by controlling the amplitude and frequency of the voltage on the heating source side;

[0019] Obtain a current conversion coefficient library, and determine a corresponding current conversion coefficient according to the current conversion coefficient library and the high-frequency AC self-heating mode, wherein the current conversion coefficient library includes: a current conversion coefficient for a heating time of 10 min, a current conversion coefficient for a heating time of 20 min…a current conversion coefficient for a heating time of Xmin, and the high-frequency AC self-heating mode corresponds to the current conversion coefficient library and includes: a first heating mode, a second heating mode…an Xth heating mode.

[0020] Preferably, the obtaining of the current conversion coefficient library comprises:

[0021] Perform battery pack capacity test to determine the actual capacity of the battery pack;

[0022] After sufficient rest, obtain the cell terminal voltage value in the battery pack, and determine the initial state of charge based on the relationship between the cell terminal voltage value and the state of charge;

[0023] The AC high-frequency heating process with a heating time of 10 minutes is carried out. After completion, the heating time is fully allowed to stand and the current state of charge corresponding to the heating time of 10 minutes is determined through the relationship between the single-cell terminal voltage value and the state of charge. The current value actually discharged by the battery with a heating time of 10 minutes, the initial state of charge and the battery pack capacity are determined by formula (1):

[0024]

[0025] Among them: Current real1 The actual current value discharged by the battery when the heating time is 10 minutes, and the state of charge real1 The current state of charge corresponding to the heating time of 10 minutes. real0 is the initial state of charge, Cap is the battery pack capacity;

[0026] Obtain the current value actually collected within a heating time of 10 minutes, and determine the current conversion coefficient for a heating time of 10 minutes according to formula (2):

[0027]

[0028] Among them: Factor 1 is the current value actually collected within 10 minutes of heating time, Current BMS1 is the current value actually collected within 10 minutes of heating time;

[0029] Repeat the AC high-frequency heating process with a heating time of Xmin, and obtain the actual current value discharged by the battery with a heating time of Xmin by formula (1) and formula (2) respectively;

[0030] Obtain the current value actually collected within the heating time of Xmin, and determine the current conversion coefficient of the heating time of Xmin by formula (3):

[0031]

[0032] Where: Factor X is the current conversion coefficient for heating time Xmin, Current BMSX Current is the current value actually collected within the heating time of Xmin. realX is the actual current value discharged by the battery when the heating time is Xmin, X is 10n, n is a positive number and 1≤n≤18.

[0033] Preferably, determining the target state of charge of the power battery at the target time according to the state of charge estimation related parameters and the corresponding current conversion coefficient includes:

[0034] The state of charge estimation related parameters and the current conversion coefficient are used to obtain the target state of charge of the power battery at the target time according to formula (4):

[0035]

[0036] Where: State of Charge real is the target state of charge of the power battery at the target time, init The initial charge state of the power battery at the initial moment, Current is the real-time current value collected by the BMS battery management system at the target moment, t is the time from the BMS battery management system working normally to the target moment, Cap is the battery pack capacity, and Factor is the corresponding current conversion coefficient.

[0037] According to a second aspect of an embodiment of the present invention, a device for estimating a state of charge in a power battery self-heating mode is provided, comprising:

[0038] A data acquisition module, for respectively acquiring state-of-charge estimation related parameters and the amplitude and frequency data of the control voltage on the heating source side in the state-of-charge estimation request data when receiving the state-of-charge estimation request data, wherein the state-of-charge estimation related parameters include: the initial state of charge of the power battery at the initial moment, the real-time current value collected by the BMS battery management system at the target moment, and the battery pack capacity;

[0039] A coefficient determination module, used to determine the current conversion coefficient by the amplitude and frequency of the control voltage on the heating source side;

[0040] The estimation module is used to determine the target state of charge of the power battery at a target time according to the state of charge estimation related parameters and the current conversion coefficient.

[0041] Preferably, the estimation module is used for:

[0042] The state of charge estimation related parameters and the current conversion coefficient are used to obtain the target state of charge of the power battery at the target time according to formula (4):

[0043]

[0044] Where: State of Charge real is the target state of charge of the power battery at the target time, initThe initial charge state of the power battery at the initial moment, Current is the real-time current value collected by the BMS battery management system at the target moment, t is the time from the BMS battery management system working normally to the target moment, Cap is the battery pack capacity, and Factor is the corresponding current conversion coefficient.

[0045] According to a third aspect of an embodiment of the present invention, there is provided a vehicle, comprising:

[0046] one or more processors;

[0047] a memory for storing the one or more processor-executable instructions;

[0048] Wherein, the one or more processors are configured to:

[0049] Execute the method described in the first aspect of the embodiment of the present invention.

[0050] According to a fourth aspect of an embodiment of the present invention, a non-temporary computer-readable storage medium is provided. When instructions in the storage medium are executed by a processor of a terminal, the terminal is enabled to execute the method described in the first aspect of the embodiment of the present invention.

[0051] According to a fifth aspect of an embodiment of the present invention, an application product is provided. When the application product is running on a terminal, the terminal executes the method described in the first aspect of the embodiment of the present invention.

[0052] The beneficial effects of the present invention are:

[0053] This patent provides a method, device and vehicle for estimating the state of charge of a power battery in the self-heating mode. The traditional ampere-hour integration method is modified, and statistical current and equivalent forms are used to correct the statistical current to estimate the state of charge of the battery in the self-heating mode, thereby ensuring the accuracy and stability of the state of charge estimation, and is not affected by the aging factors of the battery itself, the state of charge factors, the starting heating temperature, and the ending heating temperature, thereby reducing a large amount of preliminary development and calibration work.

[0054] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 is a flow chart showing a method for estimating the state of charge of a power battery in a self-heating mode according to an exemplary embodiment;

[0056] Figure 2 is a schematic block diagram of a structure of an electric vehicle data quality assessment device according to an exemplary embodiment;

[0057] Figure 3 The present invention is a schematic block diagram of a vehicle structure according to an exemplary embodiment. DETAILED DESCRIPTION

[0058] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0060] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] An embodiment of the present invention provides a method for estimating the state of charge of a power battery in a self-heating mode. The method is implemented by a vehicle, and the vehicle at least includes a CPU and the like.

[0062] Embodiment 1

[0063] Figure 1 The present invention is a flow chart of a method for estimating the state of charge of a power battery in a self-heating mode according to an exemplary embodiment. The method is used in a terminal and includes the following steps:

[0064] Step 101 : when receiving state of charge estimation request data, respectively obtaining state of charge estimation related parameters in the state of charge estimation request data and amplitude and frequency data of a heating source side control voltage.

[0065] Obtain the amplitude and frequency data of the control voltage on the heating source side. The specific contents are as follows:

[0066] Get the CAN bus status and determine whether information can be transmitted:

[0067] Yes, the amplitude and frequency data of the control voltage on the heating source side are obtained through the CAN bus. The voltage amplitude information includes the step voltage amplitude information V m (0V, kV, 2kV, 3kV, ... voltage upper limit), frequency information V f Divided into several frequencies such as A hz, B hz, Chz, etc.

[0068] If no, proceed to the next step;

[0069] Acquire the current on the BMS battery management system side, and determine the current characteristics of the BMS battery management system side through the current on the BMS battery management system side;

[0070] Acquire the current mean and variance in a predetermined time interval according to the current on the BMS battery management system side;

[0071] The amplitude and frequency data of the control voltage on the heating source side at that moment are determined according to the current mean and variance in the predetermined time interval.

[0072] Assume that n current values ​​are collected within the time Δt, namely cur1, cur2, ...curn, and the sampling period is m.

[0073] Then the mean current is:

[0074] The current variance is:

[0075]

[0076] For different amplitudes and frequencies, the corresponding currents and amplitudes are not the same;

[0077] As (Cur mean1 , Cur D1 ) corresponds to amplitude k V and frequency Ahz.

[0078] (Cur mean2 , Cur D2 ) corresponds to an amplitude of 5k V and a frequency of Ahz.

[0079] (Cur mean_n , Cur D_n ) corresponds to amplitude nk V, frequency B hz, etc.

[0080] By testing the current pair (Cur mean , Cur D ) and control voltage pair (V m , V f ) can determine the corresponding relationship between the current performance under different control voltage pairs.

[0081] When the CAN bus status cannot transmit information, it also includes:

[0082] The range interval of the BMS battery management system current is obtained, and the amplitude and frequency data of the control voltage on the heating source side at this moment are determined through the range interval of the BMS battery management system current.

[0083] Assume that n current values ​​are collected within the time Δt, namely cur1, cur2, ...curn, and the sampling period is m.

[0084] Find the maximum and minimum current values ​​within the Δt time period:

[0085] Cur max =max(cur1,cur2,...,cur n )

[0086] Cur min =min(cur1,cur2,...,cur n )

[0087] By measuring the current upper limit Cur_UpperLimit and the current lower limit Cur_UpperLimit under the control voltage frequency and amplitude offline LowerLimit.

[0088] With Cur max <Cur UpperLimitmin , and Cur min <Cur LowerLimit , the control voltage frequency and amplitude under current can be determined (V m , V f ).

[0089] The parameters related to the state of charge estimation include: the initial state of charge of the power battery at the initial moment, the current value and battery pack capacity collected in real time by the BMS battery management system at the target moment.

[0090] Step 102, determining the corresponding current conversion coefficient by the amplitude and frequency of the control voltage on the heating source side, the specific contents are as follows:

[0091] Determining a high-frequency AC self-heating mode by controlling the amplitude and frequency of the voltage on the heating source side;

[0092] Obtain a current conversion coefficient library, and determine a corresponding current conversion coefficient according to the current conversion coefficient library and the high-frequency AC self-heating mode, wherein the current conversion coefficient library includes: a current conversion coefficient for a heating time of 10 min, a current conversion coefficient for a heating time of 20 min…a current conversion coefficient for a heating time of Xmin, and the high-frequency AC self-heating mode corresponds to the current conversion coefficient library and includes: a first heating mode, a second heating mode…an Xth heating mode.

[0093] Among them, obtain the current conversion coefficient library, the specific content is as follows:

[0094] Perform battery pack capacity test to determine the actual capacity of the battery pack;

[0095] After sufficient rest, obtain the cell terminal voltage value in the battery pack, and determine the initial state of charge based on the relationship between the cell terminal voltage value and the state of charge;

[0096] The AC high-frequency heating process with a heating time of 10 minutes is carried out. After completion, the heating time is fully allowed to stand and the current state of charge corresponding to the heating time of 10 minutes is determined through the relationship between the single-cell terminal voltage value and the state of charge. The current value actually discharged by the battery with a heating time of 10 minutes, the initial state of charge and the battery pack capacity are determined by formula (1):

[0097]

[0098] Among them: Current real1 The actual current value discharged by the battery when the heating time is 10 minutes, and the state of charge real1 The current state of charge corresponding to the heating time of 10 minutes. real0 is the initial state of charge, Cap is the battery pack capacity;

[0099] Obtain the current value actually collected within a heating time of 10 minutes, and determine the current conversion coefficient for a heating time of 10 minutes according to formula (2):

[0100]

[0101] Among them: Factor 1 is the current value actually collected within 10 minutes of heating time, Current BMS1 is the current value actually collected within 10 minutes of heating time;

[0102] Repeat the AC high-frequency heating process with a heating time of Xmin, and obtain the actual current value discharged by the battery with a heating time of Xmin by formula (1) and formula (2) respectively;

[0103] Obtain the current value actually collected within the heating time Xmin, and determine the current conversion coefficient for the heating time Xmin using formula (3). First, remove the current data of the first 10 minutes and only calculate the coefficient of the next 10 minutes interval:

[0104]

[0105] Where: Factor Xis the current conversion coefficient for heating time Xmin, Current BMSX Current is the current value actually collected within the heating time of Xmin. realX is the actual current value discharged by the battery when the heating time is Xmin, X is 10n, n is a positive number and 1≤n≤18.

[0106] Step 103, determining the target state of charge of the power battery at the target time according to the state of charge estimation related parameters and the corresponding current conversion coefficient, the specific contents are as follows:

[0107] The state of charge estimation related parameters and the current conversion coefficient are used to obtain the target state of charge of the power battery at the target time according to formula (4):

[0108]

[0109] Where: State of Charge real is the target state of charge of the power battery at the target time, init The initial charge state of the power battery at the initial moment, Current is the real-time current value collected by the BMS battery management system at the target moment, t is the time from the BMS battery management system working normally to the target moment, Cap is the battery pack capacity, and Factor is the corresponding current conversion coefficient.

[0110] According to the above steps, the specific distances are as follows:

[0111] Assuming that the current single cell voltage value in the static state is 4.001V, the corresponding OCV-state of charge curve shows that the current state of charge is 80%. At this time, self-heating begins, and the self-heating time is 10 minutes. After heating, it is left to stand for 1 hour. At this time, the single cell voltage value is 3.951V, and the corresponding OCV-state of charge curve shows that the current state of charge is 78%. The battery capacity is 100Ah, then the actual cumulative Ah of discharge at this time is 2Ah, and the average current value corresponding to 10 minutes is 2*3600 / (10*60)=12A. At this time, the cumulative Ah value collected by BMS within 10 minutes is 1200A.s, and the average current value is 1200 / (10*60)=2A, so the current conversion factor Factor at this time is 12 / 2=6;

[0112] Discharge again, the discharge time is 20min, and stand for 1h. At this time, the single cell voltage is 3.943V, and the current state of charge is 74% according to the OCV-state of charge curve. The actual amount of electricity discharged at this time is 4Ah, and the amount of electricity discharged in the second 10min is 2Ah. The corresponding average current is 2*3600 / (10*60)=12A. The current value collected by BMS in 20min is 2300A.s. The current in the first 10min is basically the same as the first test, about 1200A.s. The current value collected in the second 10min is 1100A.s, and the average current value is 1100 / (10*60)=1.83. The current conversion factor at this time is 12 / 1.83=6.545.

[0113] Similarly, calculate the current conversion factor within the third 10 minutes, assuming that the Factor is 6.8.

[0114] At this time, a car needs to be self-heated. The current state of charge is 60%, the temperature is -15℃, and after heating for 25 minutes, the temperature rises to 0℃, and the self-heating stops. When entering the self-heating mode, the state of charge calculation adopts an improved Ah integration strategy, and the current value collected by the BMS is always calculated by ampere-hour integration. Assume that the accumulated Ah of the BMS in the first 10 minutes is 1150A.s, the accumulated Ah of the BMS in the second 10 minutes is 1120A.s, and the accumulated Ah of the BMS in the third 5 minutes is 580Ah. The accumulated Ah reduction value at this time is:

[0115] 1150*6+1120*6.545+580*6.8=6900+7330.4+3944=18174.4As,

[0116]

[0117] The state of charge at this time is 54.952%.

[0118] Embodiment 2

[0119] Figure 2 The present invention is a schematic block diagram of a device for estimating the state of charge of a power battery in a self-heating mode according to an exemplary embodiment, comprising:

[0120] The data acquisition module 210 is used to respectively acquire state-of-charge estimation related parameters and the amplitude and frequency data of the control voltage on the heating source side in the state-of-charge estimation request data when receiving the state-of-charge estimation request data, wherein the state-of-charge estimation related parameters include: the initial state of charge of the power battery at the initial moment, the real-time current value collected by the BMS battery management system at the target moment, and the battery pack capacity;

[0121] A coefficient determination module 220, configured to determine a current conversion coefficient by controlling the voltage amplitude and frequency at the heating source side;

[0122] The estimation module 230 is used to determine the target state of charge of the power battery at a target time according to the state of charge estimation related parameters and the current conversion coefficient.

[0123] Preferably, the estimation module is used for:

[0124] The state of charge estimation related parameters and the current conversion coefficient are used to obtain the target state of charge of the power battery at the target time according to formula (4):

[0125]

[0126] Where: State of Charge real is the target state of charge of the power battery at the target time, init The initial charge state of the power battery at the initial moment, Current is the real-time current value collected by the BMS battery management system at the target moment, t is the time from the BMS battery management system working normally to the target moment, Cap is the battery pack capacity, and Factor is the corresponding current conversion coefficient.

[0127] Embodiment 3

[0128] Figure 3 The vehicle 300 shown may include a main controller 310 and a memory 320 , wherein the memory 320 is used to store a computer program, and the main controller 310 is used to control the vehicle to execute the method of any embodiment of the present specification under the control of the computer program.

[0129] The main controller 310 is a main component of the electronic control unit (ECU) of the vehicle, and is used to execute a computer program, which can be written in an instruction set of an architecture such as x47, Arm, RISC, MIPS, SSE, etc.

[0130] The memory 320 includes, for example, a ROM (Read Only Memory), a RAM (Random Access Memory), a nonvolatile memory such as a hard disk, and the like, and is used to store the above computer programs and the like.

[0131] The vehicle in this embodiment is specifically a vehicle provided with a power battery, and may be a pure vehicle or a hybrid vehicle.

[0132] In one example, the vehicle may have Figure 2 The charge state estimation device in the power battery self-heating mode shown in is not limited here.

[0133] In one example, the vehicle may also have at least one of other hardware structures such as an engine, a motor controller, a sensing device, an input device, an interface device, an output device, a motor, a power battery, etc., which are not limited here.

[0134] The rear end of the engine (the end connected to the flywheel) can be connected to the input end of the reducer through a clutch, and the output end of the reducer is connected to the wheel axle so that the wheel can be driven to rotate through the engine.

[0135] The motor controller is used to control the motor action according to the control instructions sent by the main controller 310, for example, to control the motor output torque to drive the wheel shaft to rotate; for example, to control the motor to feed back electrical energy to the power battery.

[0136] The sensing device may include various sensors, for example, at least one of a rotation speed sensor, a posture sensor, a temperature sensor, a humidity sensor, a pressure sensor, etc.

[0137] The input device may include a key circuit, a touch screen, a microphone, a knob circuit, a throttle control device with an accelerator pedal, a brake control device with a brake pedal, and the like.

[0138] The interface device may include an earphone interface, an on-board diagnostics (OBD) interface, a charging interface, a USB interface, and the like.

[0139] Output devices may include display screens, speakers, various indicator lights, etc.

[0140] When the motor is used as an electric motor, the power battery can be used to provide electrical energy to the motor.

[0141] The present invention may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present invention.

[0142] A computer-readable storage medium may be a tangible device that can hold and store instructions used by an instruction execution device. A computer-readable storage medium may be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples of computer-readable storage media (a non-exhaustive list) include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or a raised structure in a groove on which instructions are stored, and any suitable combination of the foregoing. As used herein, a computer-readable storage medium is not to be interpreted as a transient signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through a wire.

[0143] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, optical fiber transmissions, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in the computer-readable storage medium in each computing / processing device.

[0144] The computer program instructions for performing the operation of the present invention may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages, such as Smalltalk, C++, etc., and conventional procedural programming languages, such as "C" language or similar programming languages. Computer-readable program instructions may be executed entirely on a user's computer, partially on a user's computer, as an independent software package, partially on a user's computer, partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., using an Internet service provider to connect via the Internet). In some embodiments, an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), may be personalized by utilizing the state information of the computer-readable program instructions, and the electronic circuit may execute the computer-readable program instructions, thereby realizing various aspects of the present invention.

[0145] Various aspects of the present invention are described herein with reference to the flow charts and / or block diagrams of the methods, devices (systems) and computer program products according to embodiments of the present invention. It should be understood that each box of the flow chart and / or block diagram and the combination of each box in the flow chart and / or block diagram can be implemented by computer-readable program instructions.

[0146] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, thereby producing a machine, so that when these instructions are executed by the processor of the computer or other programmable data processing device, a device that implements the functions / actions specified in one or more boxes in the flowchart and / or block diagram is generated. These computer-readable program instructions can also be stored in a computer-readable storage medium, and these instructions cause the computer, programmable data processing device, and / or other equipment to work in a specific manner, so that the computer-readable medium storing the instructions includes a manufactured product, which includes instructions for implementing various aspects of the functions / actions specified in one or more boxes in the flowchart and / or block diagram.

[0147] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device so that a series of operating steps are performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to implement the functions / actions specified in one or more boxes in the flowchart and / or block diagram.

[0148] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily realized. Therefore, without departing from the general concept defined by the claims and equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. A method for estimating the state of charge of a power battery in a self-heating mode, characterized in that: include: When receiving the state of charge estimation request data, respectively obtaining the state of charge estimation related parameters in the state of charge estimation request data and the amplitude and frequency data of the control voltage on the heating source side, wherein the state of charge estimation related parameters include: the initial state of charge of the power battery at the initial moment, the real-time current value collected by the BMS battery management system at the target moment, and the battery pack capacity; Determine the corresponding current conversion coefficient by controlling the voltage amplitude and frequency on the heating source side; Determining a target state of charge of the power battery at the target time according to the state of charge estimation related parameters and the corresponding current conversion coefficient; Obtain the amplitude and frequency data of the control voltage on the heating source side, including: Obtain the CAN bus status and determine whether information can be transmitted: Yes, the amplitude and frequency data of the control voltage on the heating source side are obtained through the CAN bus; If no, proceed to the next step; Acquire the current on the BMS battery management system side, and determine the current characteristics of the BMS battery management system side through the current on the BMS battery management system side; Acquire the current mean and variance in a predetermined time interval according to the current on the BMS battery management system side; Determine the amplitude and frequency data of the control voltage on the heating source side at that moment according to the current mean and variance in the predetermined time interval; When the CAN bus status cannot transmit information, it also includes: Obtaining a range of the BMS battery management system current, and determining the amplitude and frequency data of the control voltage on the heating source side at that moment through the range of the BMS battery management system current; The corresponding current conversion coefficient is determined by the amplitude and frequency of the control voltage on the heating source side, including: Determining a high-frequency AC self-heating mode by controlling the amplitude and frequency of the voltage on the heating source side; Acquire a current conversion coefficient library, and determine a corresponding current conversion coefficient according to the current conversion coefficient library and the high-frequency AC self-heating mode, wherein the current conversion coefficient library includes: a current conversion coefficient for a heating time of 10 min, a current conversion coefficient for a heating time of 20 min...a current conversion coefficient for a heating time of Xmin, and the high-frequency AC self-heating mode corresponds to the current conversion coefficient library and includes: a first heating mode, a second heating mode...an Xth heating mode; The method of obtaining a current conversion coefficient library comprises: Perform battery pack capacity test to determine the actual capacity of the battery pack; After sufficient rest, obtain the cell terminal voltage value in the battery pack, and determine the initial state of charge based on the relationship between the cell terminal voltage value and the state of charge; The AC high-frequency heating process with a heating time of 10 minutes is carried out. After completion, the heating time is fully allowed to stand and the current state of charge corresponding to the heating time of 10 minutes is determined through the relationship between the single-cell terminal voltage value and the state of charge. The current value actually discharged by the battery with a heating time of 10 minutes, the initial state of charge and the battery pack capacity are determined by formula (1): Among them: Current real1 The actual current value discharged by the battery when the heating time is 10 minutes, and the state of charge real1 The current state of charge corresponding to the heating time of 10 minutes. real0 is the initial state of charge, Cap is the battery pack capacity; Obtain the current value actually collected within a heating time of 10 minutes, and determine the current conversion coefficient for a heating time of 10 minutes according to formula (2): Among them: Factor1 is the current conversion coefficient when the heating time is 10 minutes, Current BMS1 is the current value actually collected within 10 minutes of heating time; Repeat the AC high-frequency heating process with a heating time of Xmin, and obtain the actual current value discharged by the battery with a heating time of Xmin by formula (1) and formula (2) respectively; Obtain the current value actually collected within the heating time of Xmin, and determine the current conversion coefficient of the heating time of Xmin by formula (3): Where: Factor X is the current conversion coefficient for heating time Xmin, Current BMSX Current is the current value actually collected within the heating time of Xmin. realX is the actual current value discharged by the battery when the heating time is Xmin, X is 10n, n is a positive number and 1≤n≤18; The determining the target state of charge of the power battery at the target time according to the state of charge estimation related parameters and the corresponding current conversion coefficient includes: The state of charge estimation related parameters and the current conversion coefficient are used to obtain the target state of charge of the power battery at the target time according to formula (4): Where: State of Charge real is the target state of charge of the power battery at the target time, init The initial charge state of the power battery at the initial moment, Current is the real-time current value collected by the BMS battery management system at the target moment, t is the time from the BMS battery management system working normally to the target moment, Cap is the battery pack capacity, and Factor is the corresponding current conversion coefficient.

2. A device for estimating the state of charge of a power battery in a self-heating mode, characterized in that: include: A data acquisition module, for respectively acquiring state-of-charge estimation related parameters and the amplitude and frequency data of the control voltage on the heating source side in the state-of-charge estimation request data when receiving the state-of-charge estimation request data, wherein the state-of-charge estimation related parameters include: the initial state of charge of the power battery at the initial moment, the real-time current value collected by the BMS battery management system at the target moment, and the battery pack capacity; A coefficient determination module, used to determine the current conversion coefficient by the amplitude and frequency of the control voltage on the heating source side; An estimation module, used to determine a target state of charge of the power battery at a target time according to the state of charge estimation related parameters and a current conversion coefficient; Obtain the amplitude and frequency data of the control voltage on the heating source side, including: Obtain the CAN bus status and determine whether information can be transmitted: Yes, the amplitude and frequency data of the control voltage on the heating source side are obtained through the CAN bus; If no, proceed to the next step; Acquire the current on the BMS battery management system side, and determine the current characteristics of the BMS battery management system side through the current on the BMS battery management system side; Acquire the current mean and variance in a predetermined time interval according to the current on the BMS battery management system side; Determine the amplitude and frequency data of the control voltage on the heating source side at that moment according to the current mean and variance in the predetermined time interval; When the CAN bus status cannot transmit information, it also includes: Obtaining a range of the BMS battery management system current, and determining the amplitude and frequency data of the control voltage on the heating source side at that moment through the range of the BMS battery management system current; The corresponding current conversion coefficient is determined by the amplitude and frequency of the control voltage on the heating source side, including: Determining a high-frequency AC self-heating mode by controlling the amplitude and frequency of the voltage on the heating source side; Acquire a current conversion coefficient library, and determine a corresponding current conversion coefficient according to the current conversion coefficient library and the high-frequency AC self-heating mode, wherein the current conversion coefficient library includes: a current conversion coefficient for a heating time of 10 min, a current conversion coefficient for a heating time of 20 min...a current conversion coefficient for a heating time of Xmin, and the high-frequency AC self-heating mode corresponds to the current conversion coefficient library and includes: a first heating mode, a second heating mode...an Xth heating mode; The method of obtaining a current conversion coefficient library comprises: Perform battery pack capacity test to determine the actual capacity of the battery pack; After sufficient rest, obtain the cell terminal voltage value in the battery pack, and determine the initial state of charge based on the relationship between the cell terminal voltage value and the state of charge; The AC high-frequency heating process with a heating time of 10 minutes is carried out. After completion, the heating time is fully allowed to stand and the current state of charge corresponding to the heating time of 10 minutes is determined through the relationship between the single-cell terminal voltage value and the state of charge. The current value actually discharged by the battery with a heating time of 10 minutes, the initial state of charge and the battery pack capacity are determined by formula (1): Among them: Current real1 The actual current value discharged by the battery when the heating time is 10 minutes, and the state of charge real1 The current state of charge corresponding to the heating time of 10 minutes. real0 is the initial state of charge, Cap is the battery pack capacity; Obtain the current value actually collected within a heating time of 10 minutes, and determine the current conversion coefficient for a heating time of 10 minutes according to formula (2): Among them: Factor1 is the current conversion coefficient when the heating time is 10 minutes, Current BMS1 is the current value actually collected within 10 minutes of heating time; Repeat the AC high-frequency heating process with a heating time of Xmin, and obtain the actual current value discharged by the battery with a heating time of Xmin by formula (1) and formula (2) respectively; Obtain the current value actually collected within the heating time of Xmin, and determine the current conversion coefficient of the heating time of Xmin by formula (3): Where: Factor X is the current conversion coefficient for heating time Xmin, Current BMSX Current is the current value actually collected within the heating time of Xmin. realX is the actual current value discharged by the battery when the heating time is Xmin, X is 10n, n is a positive number and 1≤n≤18; The determining the target state of charge of the power battery at the target time according to the state of charge estimation related parameters and the corresponding current conversion coefficient includes: The state of charge estimation related parameters and the current conversion coefficient are used to obtain the target state of charge of the power battery at the target time according to formula (4): Where: State of Charge real is the target state of charge of the power battery at the target time, init The initial charge state of the power battery at the initial moment, Current is the real-time current value collected by the BMS battery management system at the target moment, t is the time from the BMS battery management system working normally to the target moment, Cap is the battery pack capacity, and Factor is the corresponding current conversion coefficient.

3. A vehicle, characterized in that: include: one or more processors; a memory for storing the one or more processor-executable instructions; Wherein, the one or more processors are configured to: Execute a method for estimating the state of charge of a power battery in a self-heating mode as described in claim 1.

4. A non-transitory computer-readable storage medium, characterized in that: When the instructions in the storage medium are executed by the processor of the terminal, the terminal is enabled to execute the method for estimating the state of charge in the self-heating mode of a power battery as claimed in claim 1.

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