A battery emulation-based electric vehicle charging failure early warning method and system

Abstract

The application relates to a battery simulation-based electric vehicle charging fault early warning method and system, which comprises the following steps: monitoring actual charging state information of an electric vehicle, charging state information of a non-vehicle-mounted charger and battery charging demand information of the electric vehicle; and based on the actual charging state information of the electric vehicle, the charging state information of the non-vehicle-mounted charger, the battery charging demand information of the electric vehicle and simulated charging state information of the electric vehicle, the electric vehicle is subjected to charging fault early warning. The technical scheme provided by the application simultaneously considers charging parameters of the electric vehicle side and the generator side, and the electric vehicle issues a charging fault early warning based on the charging parameters, so that the identification accuracy of the electric vehicle charging fault is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle charging and battery replacement, and in particular to an electric vehicle charging fault early warning method and system based on battery simulation. Background Art

[0002] As the global energy crisis intensifies and environmental issues become increasingly prominent, the significant advantages of electric vehicles over traditional vehicles in energy conservation and emissions reduction are gaining attention from governments and automakers worldwide. The rapid development of the electric vehicle industry has driven the development of electric vehicle charging infrastructure. Countries around the world have implemented a series of incentives and invested heavily in supporting the construction of electric vehicle charging stations and charging piles to meet the charging needs of electric vehicles.

[0003] With the release of a series of standards related to electric vehicle charging infrastructure, energy supply companies have also invested in the construction of electric vehicle charging infrastructure such as charging stations and charging piles. Seven standards related to the technical requirements and testing specifications for electric vehicle charging equipment have been updated and released, making great progress in the construction of electric vehicle charging infrastructure.

[0004] With the construction and operation of a large number of electric vehicle charging equipment, charging reliability and safety have gradually become a focus of attention. The operating status of electric vehicle charging equipment not only affects its own reliability but also the service life of the power battery. Routine maintenance and inspection of electric vehicle charging equipment is not to be neglected, but fault monitoring during the charging process is also crucial.

[0005] Research has been conducted on monitoring and early warning methods for electric vehicle charging faults. A mobile monitoring and fault diagnosis system for electric vehicle charging piles uses a fault tree method to analyze and diagnose charging pile faults. Charging facility detection technology and its application in the field are analyzed, and common faults encountered during field testing are classified and analyzed. This article analyzes and describes fault diagnosis methods for pure electric vehicles where the charging port indicator light does not illuminate and charging does not occur after the charging gun is plugged in. Using the EV300 electric vehicle charging system as an example, this article explores fault diagnosis methods for electric vehicle charging systems, including charging gun insertion sensing signal faults and charging conduction signal faults. These electric vehicle charging fault diagnosis methods focus solely on potential faults on the charger side, and do not monitor and provide early warnings for potential faults on the battery management system side during the charging process. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide an electric vehicle charging fault warning method based on battery simulation. The method takes into account the charging parameters of the electric vehicle side and the generator side at the same time, and issues a charging fault warning based on the charging parameters of the electric vehicle, thereby improving the accuracy of identifying electric vehicle charging faults.

[0007] The purpose of the present invention is achieved by adopting the following technical solutions:

[0008] The present invention provides an electric vehicle charging fault early warning method based on battery simulation, wherein the method comprises:

[0009] Monitor the actual charging status information of electric vehicles, the charging status information of off-board chargers, and the battery charging demand information of electric vehicles;

[0010] Based on the actual charging status information of the electric vehicle, the charging status information of the off-board charger, the battery charging demand information of the electric vehicle and the simulated charging status information of the electric vehicle, a charging failure warning is issued for the electric vehicle.

[0011] Preferably, the monitoring of the actual charging status information of the electric vehicle, the charging status information of the off-board charger and the battery charging demand information of the electric vehicle includes:

[0012] Use CAN bus monitoring technology to monitor BCS messages, CCS messages and BCL messages during the communication process between the off-board charger and the electric vehicle BMS;

[0013] Parse the BCS, CCS, and BCL messages between the off-board charger and the electric vehicle's BMS during communication to obtain the actual charging status of the electric vehicle, the charging status of the off-board charger, and the battery charging demand information of the electric vehicle;

[0014] The actual charging status information of the electric vehicle includes the charging current, charging voltage and battery SOC of the electric vehicle during the actual charging process;

[0015] The charging status information of the off-board charger includes the charging current and charging voltage actually output by the off-board charger;

[0016] The battery charging requirement information of the electric vehicle includes the battery charging current requirement and the battery charging voltage requirement of the electric vehicle.

[0017] Preferably, the process of determining the simulated charging status information of the electric vehicle includes:

[0018] The battery parameters of the electric vehicle and the BMS simulation technology are used to simulate the electric vehicle charging response environment to obtain the simulated charging state information of the electric vehicle in the electric vehicle charging response environment.

[0019] Furthermore, the battery parameters of the electric vehicle include:

[0020] The battery type, number of battery packs, battery rated capacity, battery rated voltage, battery initial temperature, battery initial SOC, battery maximum allowable charging current, battery maximum allowable total charging voltage and battery maximum allowable temperature of the electric vehicle.

[0021] Furthermore, the simulated charging state information of the electric vehicle includes: charging current, charging voltage and battery SOC of the electric vehicle in a simulated charging response environment.

[0022] Preferably, the charging failure warning for the electric vehicle based on the actual charging status information of the electric vehicle, the charging status information of the off-board charger, the battery charging demand information of the electric vehicle and the simulated charging status information of the electric vehicle includes:

[0023] comparing actual charging state information of the electric vehicle with simulated charging state information of the electric vehicle to obtain a first comparison result;

[0024] comparing the charging state information of the off-board charger with the battery charging requirement information of the electric vehicle to obtain a second comparison result;

[0025] When the first comparison result satisfies the first constraint condition and the second comparison result satisfies the second constraint condition, a charging failure warning is issued to the electric vehicle;

[0026] The first constraint condition includes: the deviation values ​​of the charging current and charging voltage between the actual charging state information of the electric vehicle and the simulated charging state information of the electric vehicle are both less than 2%, and the deviation value of the battery SOC between the actual charging state information of the electric vehicle and the simulated charging state information of the electric vehicle is less than 5%;

[0027] The second constraint condition includes: a deviation value between the charging current in the charging status information of the off-board charger and the charging current requirement in the battery charging requirement information of the electric vehicle is less than 2%, and a deviation value between the charging voltage in the charging status information of the off-board charger and the charging voltage requirement in the battery charging requirement information of the electric vehicle is less than 2%.

[0028] The present invention provides an electric vehicle charging fault early warning system based on battery simulation, characterized in that the system comprises:

[0029] A monitoring module is used to monitor the actual charging status information of the electric vehicle, the charging status information of the off-board charger, and the battery charging demand information of the electric vehicle;

[0030] The early warning module is used to provide charging failure early warning for electric vehicles based on the actual charging status information of the electric vehicle, the charging status information of the off-board charger, the battery charging demand information of the electric vehicle, and the simulated charging status information of the electric vehicle.

[0031] Preferably, the monitoring module includes:

[0032] The receiving unit is used to monitor the BCS messages, CCS messages and BCL messages during the communication between the off-board charger and the electric vehicle BMS using CAN bus monitoring technology;

[0033] The parsing unit is used to parse the BCS message, CCS message and BCL message during the communication process between the off-board charger and the electric vehicle BMS, and obtain the actual charging status information of the electric vehicle, the charging status information of the off-board charger and the battery charging demand information of the electric vehicle;

[0034] The actual charging status information of the electric vehicle includes the charging current, charging voltage and battery SOC of the electric vehicle during the actual charging process;

[0035] The charging status information of the off-board charger includes the charging current and charging voltage actually output by the off-board charger;

[0036] The battery charging requirement information of the electric vehicle includes the battery charging current requirement and the battery charging voltage requirement of the electric vehicle.

[0037] Preferably, the process of determining the simulated charging status information of the electric vehicle includes:

[0038] The battery parameters of the electric vehicle and the BMS simulation technology are used to simulate the electric vehicle charging response environment to obtain the simulated charging state information of the electric vehicle in the electric vehicle charging response environment.

[0039] Furthermore, the battery parameters of the electric vehicle include:

[0040] The battery type, number of battery packs, battery rated capacity, battery rated voltage, battery initial temperature, battery initial SOC, battery maximum allowable charging current, battery maximum allowable total charging voltage and battery maximum allowable temperature of the electric vehicle.

[0041] Furthermore, the simulated charging state information of the electric vehicle includes: charging current, charging voltage and battery SOC of the electric vehicle in a simulated charging response environment.

[0042] Preferably, the early warning module includes:

[0043] a first comparing unit, configured to compare actual charging state information of the electric vehicle with simulated charging state information of the electric vehicle to obtain a first comparison result;

[0044] a second comparing unit, configured to compare the charging state information of the off-board charger with the battery charging requirement information of the electric vehicle to obtain a second comparison result;

[0045] an early warning unit, configured to issue a charging failure early warning to the electric vehicle when the first comparison result satisfies a first constraint condition and the second comparison result satisfies a second constraint condition;

[0046] The first constraint condition includes: the deviation values ​​of the charging current and charging voltage between the actual charging state information of the electric vehicle and the simulated charging state information of the electric vehicle are both less than 2%, and the deviation value of the battery SOC between the actual charging state information of the electric vehicle and the simulated charging state information of the electric vehicle is less than 5%;

[0047] The second constraint condition includes: a deviation value between the charging current in the charging status information of the off-board charger and the charging current requirement in the battery charging requirement information of the electric vehicle is less than 2%, and a deviation value between the charging voltage in the charging status information of the off-board charger and the charging voltage requirement in the battery charging requirement information of the electric vehicle is less than 2%.

[0048] Compared with the closest prior art, the present invention has the following beneficial effects:

[0049] The technical solution provided by this invention monitors the actual charging status of electric vehicles, the charging status of off-board chargers, and the charging requirements of the electric vehicle's batteries. Based on this information, the charging status of the off-board chargers, the charging requirements of the electric vehicle's batteries, and the simulated charging status of the electric vehicle, it provides a charging fault warning for the electric vehicle. This solution considers charging parameters on both the electric vehicle side and the generator side, and issues a charging fault warning based on these charging parameters, thereby improving the accuracy of identifying charging faults in electric vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a flow chart of an electric vehicle charging fault early warning method based on battery simulation;

[0051] Figure 2 This is a functional module diagram for realizing electric vehicle charging fault warning in an embodiment of the present invention;

[0052] Figure 3 This is a structural diagram of an electric vehicle charging fault warning system based on battery simulation. DETAILED DESCRIPTION

[0053] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. 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 making creative efforts shall fall within the scope of protection of the present invention.

[0055] The present invention provides an electric vehicle charging fault early warning method based on battery simulation, such as Figure 1 As shown, the method includes:

[0056] Step 101: Monitor the actual charging status information of the electric vehicle, the charging status information of the off-board charger, and the battery charging demand information of the electric vehicle;

[0057] Step 102: Based on the actual charging status information of the electric vehicle, the charging status information of the off-board charger, the battery charging demand information of the electric vehicle, and the simulated charging status information of the electric vehicle, a charging failure warning is issued to the electric vehicle.

[0058] In the best embodiment of the present invention, the functional module diagram for realizing electric vehicle charging fault warning is as follows: Figure 2 As shown, it includes a power vehicle charging model, a measurement signal receiving module, a CAN bus monitoring module, a central data processing unit, and an electric vehicle and non-on-board charger charging interaction module;

[0059] The power vehicle charging model is used to simulate the electric vehicle charging response environment based on the battery parameters of the electric vehicle and the BMS simulation technology, and input the simulated charging status information of the electric vehicle in the electric vehicle charging response environment into the central data processing module; the human-machine interface module displays the simulated electric vehicle charging status information and provides an interface for setting battery parameters. It can be manually set according to the type, specifications and parameters of the electric vehicle power battery, and can also monitor the battery charging status in real time.

[0060] The measurement signal receiving module transmits the measured actual charging current or voltage of the electric vehicle to the power vehicle charging model to simulate the charging response;

[0061] The CAN bus monitoring module is used to monitor the BCS message (battery charging status message), CCS message (motor charging status message) and BCL message (battery charging demand message) during the communication process between the off-board charger and the electric vehicle BMS.

[0062] The charging interaction module between electric vehicles and off-board chargers: In the third stage (charging stage) of the charging communication process between the off-board charger and the electric vehicle BMS, the BMS sends a battery charging requirement message (BCL) and a battery charging status message (BCS) to the off-board charger, and the off-board charger sends a charger charging status message (CCS) to the BMS.

[0063] The central data processing unit monitors the actual charging status information of the electric vehicle, the charging status information of the off-board charger and the charging demand information of the electric vehicle by parsing the BCS messages, CCS messages and BCL messages monitored by the CAN bus monitoring module, and compares the simulated charging status information of the electric vehicle in the electric vehicle charging response environment with the actual charging status information of the electric vehicle. At the same time, it compares the charging status information of the off-board charger with the battery charging demand information of the electric vehicle, so as to timely discover charging faults and issue alarm prompts.

[0064] Specifically, step 101 includes:

[0065] Step 101-1. Use CAN bus monitoring technology to monitor the BCS message, CCS message and BCL message during the communication process between the non-onboard charger and the electric vehicle BMS;

[0066] Step 101-2. parse the BCS message, CCS message, and BCL message between the off-board charger and the electric vehicle BMS during the communication process to obtain the actual charging status information of the electric vehicle, the charging status information of the off-board charger, and the battery charging demand information of the electric vehicle;

[0067] The actual charging status information of the electric vehicle includes the charging current, charging voltage and battery SOC of the electric vehicle during the actual charging process;

[0068] The charging status information of the off-board charger includes the charging current and charging voltage actually output by the off-board charger;

[0069] The battery charging requirement information of the electric vehicle includes the battery charging current requirement and the battery charging voltage requirement of the electric vehicle.

[0070] The CAN bus monitoring technology uses the USBCAN-2I interface card as a CAN communication node to connect to the CAN communication network of the off-board charger and the battery management system. The CAN communication node acts as a third-party CAN monitoring unit and only receives and parses the communication messages sent between the off-board charger and the electric vehicle battery management system according to the communication protocol during the charging communication process.

[0071] Specifically, the process of determining the simulated charging status information of the electric vehicle includes:

[0072] The battery parameters of the electric vehicle and the BMS simulation technology are used to simulate the electric vehicle charging response environment to obtain the simulated charging state information of the electric vehicle in the electric vehicle charging response environment.

[0073] In the best embodiment of the present invention, the charging mode of the electric vehicle includes constant current charging and constant voltage charging. When the battery parameters of the electric vehicle and the BMS simulation technology are used to simulate the charging response process of the electric vehicle, the charging mode of the electric vehicle is controlled by the electric vehicle BMS, and the open circuit voltage U oc The relationship between the load and the battery state of charge (SOC) is expressed using Gregory L.Plett's "composite model," and the load relationship is as follows:

[0074]

[0075] Where K1, K2, K3, K4, and K0 are fitting coefficients. The reorganized fitting coefficients under different battery types can be obtained by the power vehicle charging model parameter identification method. In addition, the battery internal resistance characteristics include the polarization internal resistance caused by concentration polarization and electrochemical polarization, and the ohmic internal resistance characteristics caused by resistance polarization. Two RC parallel circuits in series with the ohmic internal resistance can jointly simulate the battery internal resistance characteristics.

[0076] The battery charging response simulation model of the electric vehicle is based on the measured charging output and obtains the battery voltage, current, SOC and temperature and other charging response information through simulation calculation. The battery SOC expression in the discrete time domain is:

[0077]

[0078] Where C is the capacity of the single cell, η0 is the benchmark coulombic efficiency, is the SOC influence coefficient of the single battery, is the temperature influence coefficient of the single battery, SOC k is the battery capacity of the single battery in the kth calculation cycle, SOC k-1 is the battery capacity of the single battery in the k-1th calculation cycle, I C(k-1) is the charging current of the single battery in the k-1th calculation cycle, and Δt is the duration of the calculation cycle;

[0079] In constant current charging mode, the charging voltage is calculated as follows:

[0080] U Tk =f Uoc (SOC k )+U P1k +U P2k +I Ck ROk

[0081]

[0082] Among them, U P1k is the concentration polarization voltage of the single cell in the kth calculation cycle, U P2k is the electrochemical polarization voltage of the single cell in the kth calculation cycle, U P1(k-1) is the concentration polarization voltage of the single cell in the k-1th calculation cycle, U P2(k-1) is the electrochemical polarization voltage of the single cell in the k-1th calculation cycle, f Uoc (SOC k ) is the open circuit voltage of the single cell in the kth calculation cycle, I Ck is the charging current of the single battery in the kth calculation cycle, R OK is the first polarization internal resistance of the single cell in the kth calculation cycle, R 1(k-1) is the second polarization internal resistance of the single cell in the k-1th calculation cycle, I C(k-1) is the charging current of the single battery in the k-1th calculation cycle, τ 1(k-1) is the first polarization time constant of the single cell in the k-1th calculation cycle, R 2(k-1) is the third polarization internal resistance of the single cell in the k-1th calculation cycle, τ 2(k-1) is the second polarization time constant of the single cell in the k-1th calculation cycle;

[0083] In constant voltage charging mode, the charging current is calculated as:

[0084]

[0085] Among them, U ck is the charging voltage under constant voltage charging mode, is the charging voltage of the single cell in the kth calculation cycle.

[0086] The calculation formula for battery temperature is:

[0087]

[0088] Where Q k is the heat generated by the single cell in the kth calculation cycle, Q1 is the unit electrochemical reaction heat, Φ k is the heat dissipation of the single battery in the kth calculation cycle, T k is the battery temperature of the single battery in the kth calculation cycle, T k+1 is the battery temperature of the single battery in the k+1th calculation cycle, T m is the ambient temperature, R kis the thermal resistance of the conduction process of the single battery in the kth calculation cycle, R 1k is the second polarization internal resistance of the single cell in the kth calculation cycle, R 2k is the third polarization internal resistance of the single cell in the kth calculation cycle.

[0089] Furthermore, the battery parameters of the electric vehicle include:

[0090] The battery type, number of battery packs, battery rated capacity, battery rated voltage, battery initial temperature, battery initial SOC, battery maximum allowable charging current, battery maximum allowable total charging voltage and battery maximum allowable temperature of the electric vehicle.

[0091] Furthermore, the simulated charging state information of the electric vehicle in the electric vehicle charging response environment includes: charging current, charging voltage and battery SOC of the electric vehicle in the simulated charging response environment.

[0092] In the best embodiment of the present invention, the charging response of an electric vehicle can be simulated through the battery parameters of the electric vehicle, the BMS simulation technology, and the maximum output of the off-board charging pile to which the electric vehicle is connected. Depending on the parameters of the electric vehicle, the charging process of electric vehicles of different types and specifications can be simulated.

[0093] Specifically, step 102 includes:

[0094] Step 102-1. Compare the actual charging status information of the electric vehicle with the simulated charging status information of the electric vehicle to obtain a first comparison result;

[0095] Step 102-2 compares the charging status information of the non-onboard charger and the battery charging demand information of the electric vehicle to obtain a second comparison result;

[0096] Step 102-3. When the first comparison result satisfies the first constraint condition and the second comparison result satisfies the second constraint condition, a charging failure warning is issued to the electric vehicle;

[0097] The first constraint condition includes: the deviation values ​​of the charging current and charging voltage between the actual charging state information of the electric vehicle and the simulated charging state information of the electric vehicle are both less than 2%, and the deviation value of the battery SOC between the actual charging state information of the electric vehicle and the simulated charging state information of the electric vehicle is less than 5%;

[0098] The second constraint condition includes: a deviation value between the charging current in the charging status information of the off-board charger and the charging current requirement in the battery charging requirement information of the electric vehicle is less than 2%, and a deviation value between the charging voltage in the charging status information of the off-board charger and the charging voltage requirement in the battery charging requirement information of the electric vehicle is less than 2%.

[0099] In the best embodiment of the present invention, more than 10 types of faults including BMS function failure can be identified by comparing the charge status information deviation values.

[0100] In a preferred embodiment of the present invention, CAN bus monitoring technology is used to analyze CAN communication messages between an off-board charger and the electric vehicle's battery management system (BMS) during the charging process. This allows real-time acquisition of charging status information from the off-board charger and the electric vehicle, as well as the electric vehicle's charging demand information. The simulated electric vehicle charging status information is then compared with the electric vehicle's charging status information, and the off-board charger's charging status information is then compared with the electric vehicle's charging demand information to determine whether the charging process is normal. If the difference between the voltage and current in the simulated electric vehicle charging status information and the actual battery voltage and current is less than 2%, and the difference between the battery SOC in the simulated electric vehicle charging status information and the actual battery SOC is less than 5%, and the difference between the off-board charger's charging voltage and current and the electric vehicle's charging voltage and current requirements is less than 2%, then the charging process is normal. Otherwise, it indicates an error in the charging process. Specific analysis of the difference information can identify charging fault information, thereby providing a charging fault warning.

[0101] The present invention provides an electric vehicle charging fault early warning system based on battery simulation, characterized in that the system comprises:

[0102] A monitoring module is used to monitor the actual charging status information of the electric vehicle, the charging status information of the off-board charger, and the battery charging demand information of the electric vehicle;

[0103] The early warning module is used to provide charging failure early warning for electric vehicles based on the actual charging status information of the electric vehicle, the charging status information of the off-board charger, the battery charging demand information of the electric vehicle, and the simulated charging status information of the electric vehicle.

[0104] Specifically, the monitoring module includes:

[0105] The receiving unit is used to monitor the BCS messages, CCS messages and BCL messages during the communication between the off-board charger and the electric vehicle BMS using CAN bus monitoring technology;

[0106] The parsing unit is used to parse the BCS message, CCS message and BCL message during the communication process between the off-board charger and the electric vehicle BMS, and obtain the actual charging status information of the electric vehicle, the charging status information of the off-board charger and the battery charging demand information of the electric vehicle;

[0107] The actual charging status information of the electric vehicle includes the charging current, charging voltage and battery SOC of the electric vehicle during the actual charging process;

[0108] The charging status information of the off-board charger includes the charging current and charging voltage actually output by the off-board charger;

[0109] The battery charging requirement information of the electric vehicle includes the battery charging current requirement and the battery charging voltage requirement of the electric vehicle.

[0110] Specifically, the process of determining the simulated charging status information of the electric vehicle includes:

[0111] The battery parameters of the electric vehicle and the BMS simulation technology are used to simulate the electric vehicle charging response environment to obtain the simulated charging state information of the electric vehicle in the electric vehicle charging response environment.

[0112] Furthermore, the battery parameters of the electric vehicle include:

[0113] The battery type, number of battery packs, battery rated capacity, battery rated voltage, battery initial temperature, battery initial SOC, battery maximum allowable charging current, battery maximum allowable total charging voltage and battery maximum allowable temperature of the electric vehicle.

[0114] Furthermore, the simulated charging state information of the electric vehicle includes: charging current, charging voltage and battery SOC of the electric vehicle in a simulated charging response environment.

[0115] Specifically, the early warning module includes:

[0116] a first comparing unit, configured to compare actual charging state information of the electric vehicle with simulated charging state information of the electric vehicle to obtain a first comparison result;

[0117] a second comparing unit, configured to compare the charging state information of the off-board charger with the battery charging requirement information of the electric vehicle to obtain a second comparison result;

[0118] an early warning unit, configured to issue a charging failure early warning to the electric vehicle when the first comparison result satisfies a first constraint condition and the second comparison result satisfies a second constraint condition;

[0119] The first constraint condition includes: the deviation values ​​of the charging current and charging voltage between the actual charging state information of the electric vehicle and the simulated charging state information of the electric vehicle are both less than 2%, and the deviation value of the battery SOC between the actual charging state information of the electric vehicle and the simulated charging state information of the electric vehicle is less than 5%;

[0120] The second constraint condition includes: a deviation value between the charging current in the charging status information of the off-board charger and the charging current requirement in the battery charging requirement information of the electric vehicle is less than 2%, and a deviation value between the charging voltage in the charging status information of the off-board charger and the charging voltage requirement in the battery charging requirement information of the electric vehicle is less than 2%.

[0121] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0122] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0123] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0124] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0125] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A method for early warning of electric vehicle charging failure based on battery simulation, characterized in that: The method comprises: Monitor the actual charging status information of electric vehicles, the charging status information of off-board chargers, and the battery charging demand information of electric vehicles; Based on the actual charging status information of the electric vehicle, the charging status information of the off-board charger, the battery charging demand information of the electric vehicle and the simulated charging status information of the electric vehicle, the electric vehicle charging fault warning is issued; Among them, based on the actual charging status information of the electric vehicle, the charging status information of the off-board charger, the battery charging demand information of the electric vehicle and the simulated charging status information of the electric vehicle, the charging failure warning of the electric vehicle is carried out, specifically including: comparing actual charging state information of the electric vehicle with simulated charging state information of the electric vehicle to obtain a first comparison result; comparing the charging state information of the off-board charger with the battery charging requirement information of the electric vehicle to obtain a second comparison result; When the first comparison result satisfies the first constraint condition and the second comparison result satisfies the second constraint condition, a charging failure warning is issued to the electric vehicle; The battery charging requirement information of the electric vehicle includes the battery charging current requirement and the battery charging voltage requirement of the electric vehicle; The process of determining the simulated charging state information of the electric vehicle includes: Using electric vehicle battery parameters and BMS simulation technology to simulate the electric vehicle charging response environment, and obtain the simulated charging state information of the electric vehicle in the electric vehicle charging response environment; Open circuit voltage U of a single power battery in an electric vehicle oc The relationship between the load and the battery state of charge (SOC) is expressed using a composite model, and the load relationship is as follows: Where K1, K2, K3, K4, and K0 are fitting coefficients; The electric vehicle charging model simulates the battery charging response based on the measured charging output. The battery voltage, current, SOC and temperature charging response information are obtained through simulation calculation. The battery SOC is expressed in the discrete time domain as follows: Where C is the capacity of the single cell, η0 is the benchmark coulombic efficiency, is the SOC influence coefficient of the single battery, is the temperature influence coefficient of the single battery, SOC k is the battery capacity of the single battery in the kth calculation cycle, SOC k-1 is the battery capacity of the single battery in the k-1th calculation cycle, I C(k-1) is the charging current of the single battery in the k-1th calculation cycle, and Δt is the duration of the calculation cycle; In constant current charging mode, the charging voltage is calculated as follows: The Tk =f Uoc (SOC k )+U P1k +U P2k +I Ck R Ok Among them, U P1k is the concentration polarization voltage of the single cell in the kth calculation cycle, U P2k is the electrochemical polarization voltage of the single cell in the kth calculation cycle, U P1(k-1) is the concentration polarization voltage of the single cell in the k-1th calculation cycle, U P2(k-1) is the electrochemical polarization voltage of the single cell in the k-1th calculation cycle, f Uoc (SOC k ) is the open circuit voltage of the single cell in the kth calculation cycle, I Ck is the charging current of the single battery in the kth calculation cycle, R OK is the first polarization internal resistance of the single cell in the kth calculation cycle, R 1(k-1) is the second polarization internal resistance of the single cell in the k-1th calculation cycle, I C(k-1) is the charging current of the single battery in the k-1th calculation cycle, τ 1(k-1) is the first polarization time constant of the single cell in the k-1th calculation cycle, R 2(k-1) is the third polarization internal resistance of the single cell in the k-1th calculation cycle, τ 2(k-1) is the second polarization time constant of the single cell in the k-1th calculation cycle; In constant voltage charging mode, the charging current is calculated as: Among them, U Ck is the charging voltage under constant voltage charging mode, is the charging voltage of the single battery in the kth calculation cycle; The calculation formula for battery temperature is: Where Q k is the heat generated by the single cell in the kth calculation cycle, Q1 is the unit electrochemical reaction heat, Φ k is the heat dissipation of the single battery in the kth calculation cycle, T k is the battery temperature of the single battery in the kth calculation cycle, T k+1 is the battery temperature of the single battery in the k+1th calculation cycle, T m is the ambient temperature, R k is the thermal resistance of the conduction process of the single battery in the kth calculation cycle, R 1k is the second polarization internal resistance of the single cell in the kth calculation cycle, R 2k is the third polarization internal resistance of the single cell in the kth calculation cycle.

2. The method according to claim 1, wherein The monitoring of the actual charging status information of the electric vehicle, the charging status information of the off-board charger and the battery charging demand information of the electric vehicle includes: Use CAN bus monitoring technology to monitor BCS messages, CCS messages and BCL messages during the communication process between the off-board charger and the electric vehicle BMS; Parse the BCS, CCS, and BCL messages between the off-board charger and the electric vehicle's BMS during communication to obtain the actual charging status of the electric vehicle, the charging status of the off-board charger, and the battery charging demand information of the electric vehicle; The actual charging status information of the electric vehicle includes the charging current, charging voltage and battery SOC of the electric vehicle during the actual charging process; The charging status information of the off-board charger includes the charging current and charging voltage actually output by the off-board charger.

3. The method according to claim 1, wherein The process of determining the simulated charging state information of the electric vehicle includes: The battery parameters of electric vehicles and BMS simulation technology are used to simulate the electric vehicle charging response environment and obtain the simulated charging status information of the electric vehicle in the simulated charging response environment.

4. The method according to claim 3, wherein The battery parameters of the electric vehicle include: The battery type, number of battery packs, battery rated capacity, battery rated voltage, battery initial temperature, battery initial SOC, battery maximum allowable charging current, battery maximum allowable total charging voltage and battery maximum allowable temperature of the electric vehicle.

5. The method according to claim 3, wherein The simulated charging state information of the electric vehicle includes: the charging current, charging voltage and battery SOC of the electric vehicle in the electric vehicle charging response environment.

6. The method according to claim 1, wherein The method of providing a charging fault warning for the electric vehicle based on the actual charging status information of the electric vehicle, the charging status information of the off-board charger, the battery charging demand information of the electric vehicle, and the simulated charging status information of the electric vehicle further includes: The first constraint condition includes: the deviation values ​​of the charging current and charging voltage between the actual charging state information of the electric vehicle and the simulated charging state information of the electric vehicle are both less than 2%, and the deviation value of the battery SOC between the actual charging state information of the electric vehicle and the simulated charging state information of the electric vehicle is less than 5%; The second constraint condition includes: a deviation value between the charging current in the charging status information of the off-board charger and the charging current requirement in the battery charging requirement information of the electric vehicle is less than 2%, and a deviation value between the charging voltage in the charging status information of the off-board charger and the charging voltage requirement in the battery charging requirement information of the electric vehicle is less than 2%.

7. An electric vehicle charging failure warning system based on battery simulation, used in the method according to any one of claims 1 to 6, characterized in that: The system comprises: A monitoring module is used to monitor the actual charging status information of the electric vehicle, the charging status information of the off-board charger, and the battery charging demand information of the electric vehicle; The early warning module is used to provide charging failure early warning for electric vehicles based on the actual charging status information of the electric vehicle, the charging status information of the off-board charger, the battery charging demand information of the electric vehicle, and the simulated charging status information of the electric vehicle.

8. The system according to claim 7, wherein: The monitoring module includes: The receiving unit is used to receive BCS messages, CCS messages and BCL messages during the communication process between the off-board charger and the electric vehicle BMS using CAN bus monitoring technology; The parsing unit is used to parse the BCS message, CCS message and BCL message during the communication process between the off-board charger and the electric vehicle BMS, and obtain the actual charging status information of the electric vehicle, the charging status information of the off-board charger and the battery charging demand information of the electric vehicle; The actual charging information of the electric vehicle includes the charging current, charging voltage and battery SOC of the electric vehicle during the actual charging process; The charging status information of the off-board charger includes the charging current and charging voltage actually output by the off-board charger; The battery charging requirement information of the electric vehicle includes the battery charging current requirement and the battery charging voltage requirement of the electric vehicle.

9. The system according to claim 7, wherein: The process of determining the simulated charging state information of the electric vehicle includes: The battery parameters of the electric vehicle and the BMS simulation technology are used to simulate the electric vehicle charging response environment to obtain the simulated charging state information of the electric vehicle in the electric vehicle charging response environment.

10. The system according to claim 9, wherein: The battery parameters of the electric vehicle include: The battery type, number of battery packs, battery rated capacity, battery rated voltage, battery initial temperature, battery initial SOC, battery maximum allowable charging current, battery maximum allowable total charging voltage and battery maximum allowable temperature of the electric vehicle.

11. The system according to claim 9, wherein The simulated charging state information of the electric vehicle includes: the charging current, charging voltage and battery SOC of the electric vehicle in a simulated charging response environment.

12. The system according to claim 7, wherein: The early warning module includes: a first comparing unit, configured to compare actual charging state information of the electric vehicle with simulated charging state information of the electric vehicle to obtain a first comparison result; a second comparing unit, configured to compare the charging state information of the off-board charger with the battery charging requirement information of the electric vehicle to obtain a second comparison result; an early warning unit, configured to issue a charging failure early warning to the electric vehicle when the first comparison result satisfies a first constraint condition and the second comparison result satisfies a second constraint condition; The first constraint condition includes: the deviation values ​​of the charging current and charging voltage between the actual charging state information of the electric vehicle and the simulated charging state information of the electric vehicle are both less than 2%, and the deviation value of the battery SOC between the actual charging state information of the electric vehicle and the simulated charging state information of the electric vehicle is less than 5%; The second constraint condition includes: a deviation value between the charging current in the charging status information of the off-board charger and the charging current requirement in the battery charging requirement information of the electric vehicle is less than 2%, and a deviation value between the charging voltage in the charging status information of the off-board charger and the charging voltage requirement in the battery charging requirement information of the electric vehicle is less than 2%.

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