Charging control method, charging control device, power conversion device and medium

Abstract

The present application belongs to the field of energy technology, and in particular, relates to a charging control method, a charging control device, a power conversion device, and a medium. The charging control method includes: obtaining the access status of an external power source; when the access status indicates that the external power source is connected, monitoring the working status of the battery pack, the working status including the charging state and the standby state; when it is monitored that the working state is switched from the charging state to the standby state, obtaining the voltage parameter and the charging protection parameter of the battery pack; when the voltage parameter is greater than a preset voltage threshold and the charging protection parameter does not meet the preset protection condition, outputting a stop charging instruction to the power conversion circuit to control the power conversion circuit to stop outputting the charging current to the battery pack. The charging control method provided by the present application can timely determine whether the battery pack is in a charging overvoltage state, and avoid the situation where the battery pack is repeatedly charged in an overvoltage state.

Description

Technical Field

[0001] The present invention relates to the field of new energy technologies, and in particular to a charging control method, a charging control device, a power conversion device, and a medium for a battery pack. Background Art

[0002] For many energy storage products on the market, the hardware protection circuit board directly connected to the battery pack is usually a pure hardware control. This circuit board is used to control the on and off of the battery pack's charge and discharge circuits and is generally referred to as a BMS (BATTERY MANAGEMENT SYSTEM) board. However, in order to save costs, related solutions do not have a microcontroller unit MCU for running software algorithms on such BMS boards. Instead, the control chip used to run the software algorithm, such as the BMS chip, is integrated on other circuit boards, such as a power conversion circuit board electrically connected to the BMS board. It can be understood that in battery protection, the control chip is used to trigger software protection, while the BMS circuit board automatically triggers hardware protection.

[0003] In actual applications, the overvoltage information of the battery cells during the charging process of the battery pack often cannot trigger the software protection and hardware protection synchronously in time, which can easily cause repeated charging of the battery pack and damage the battery pack.

[0004] Therefore, how to promptly detect the overvoltage state of the battery pack during the charging process to avoid repeated charging of the battery pack is a difficult problem that urgently needs to be solved in the field of new energy technology. Summary of the Invention

[0005] The main purpose of the present invention is to provide a charging control method, a charging control device, a power conversion device and a medium, which aim to monitor the state transitions of the battery pack during the charging process and determine whether the battery pack is in a charging overvoltage state based on the voltage parameters and charging protection parameters of the battery pack, thereby avoiding repeated charging of the battery pack after the battery pack has entered an overvoltage state.

[0006] According to one aspect of an embodiment of the present application, a charging control method is disclosed, including:

[0007] Get the access status of the external power supply;

[0008] When the access status indicates that the external power source is connected, monitoring the working status of the battery pack, the working status including a charging state and a standby state;

[0009] When it is monitored that the working state is switched from the charging state to the standby state, obtaining voltage parameters and charging protection parameters of the battery pack;

[0010] When the voltage parameter is greater than a preset voltage threshold and the charging protection parameter does not meet a preset protection condition, a stop charging instruction is output to the power conversion circuit to control the power conversion circuit to stop outputting charging current to the battery pack.

[0011] In some embodiments of the present application, based on the above technical solution, the voltage parameter is an average voltage of a battery cell, the battery pack includes a plurality of battery cells, and obtaining the voltage parameter of the battery pack includes:

[0012] detecting a current total voltage of the battery pack;

[0013] The average voltage of the battery cells is calculated according to the current total voltage of the battery pack and the number of the battery cells.

[0014] In some embodiments of the present application, based on the above technical solution, the charging protection parameters include battery charging parameters and charging fault parameters, and obtaining the charging protection parameters of the battery pack includes:

[0015] detecting a charging temperature and a charging current of the battery pack during charging to determine charging parameters of the battery;

[0016] detecting the operating state of the power conversion circuit board to determine the charging fault parameter;

[0017] When the charging fault parameter matches a preset fault code, or when the battery charging parameter is greater than or equal to a preset charging protection threshold, it is confirmed that the charging protection parameter meets the preset protection condition.

[0018] In some embodiments of the present application, based on the above technical solution, when the voltage parameter is greater than a preset voltage threshold and the charging protection parameter does not meet a preset protection condition, outputting a stop charging instruction to the power conversion circuit to control the power conversion circuit to stop outputting the charging current to the battery pack includes:

[0019] Get the overvoltage detection duration;

[0020] During the overvoltage detection time, if the voltage parameter continues to be greater than the preset threshold and the charging protection parameter continues to fail to meet the preset protection condition, a stop charging instruction is output to the power conversion circuit to control the power conversion circuit to stop outputting charging current to the battery pack.

[0021] In some embodiments of the present application, based on the above technical solution, after executing the stop charging instruction to stop outputting the charging current to the battery pack, the method further includes:

[0022] The state of charge of the battery pack is assigned to a fully charged state, where the state of charge is used to reflect the remaining power of the battery pack.

[0023] In some embodiments of the present application, based on the above technical solution, after assigning the state of charge of the battery pack to a fully charged state according to the stop charging instruction, the method further includes:

[0024] When it is detected that the external power supply is disconnected and then reconnected, and the state of charge of the battery pack is lower than a preset power threshold, a charging instruction is output to the power conversion circuit to control the power conversion circuit to output a charging current to the battery pack.

[0025] In some embodiments of the present application, based on the above technical solution, monitoring the working status of the battery pack includes:

[0026] Acquiring a current sampling value collected by a sampling device, wherein the sampling device is provided on the power conversion circuit board and is used to sample the current output from the power conversion circuit board to the battery pack;

[0027] Comparing the current sampling value with a preset current threshold range;

[0028] If the current sampling value is within the preset current threshold range, determining that the battery pack is in a standby state;

[0029] If the current sampling value is greater than the maximum value of the preset current threshold range, it is determined that the battery pack is in a charging state.

[0030] According to one aspect of an embodiment of the present application, a charging control device is disclosed, comprising:

[0031] A first acquisition module is configured to acquire a connection status of an external power source;

[0032] a monitoring module configured to monitor the operating state of the battery pack when the access state indicates that the external power source is connected, the operating state including a charging state and a standby state;

[0033] a second acquisition module, configured to acquire a voltage parameter and a charging protection parameter of the battery pack when monitoring that the working state is switched from the charging state to the standby state;

[0034] The charging control module is configured to output a stop charging instruction to the power conversion circuit when the voltage parameter is greater than a preset voltage threshold and the charging protection parameter does not meet a preset protection condition, so as to control the power conversion circuit to stop outputting charging current to the battery pack.

[0035] According to one aspect of an embodiment of the present application, a computer program product or computer program is provided. The computer program product or computer program includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the charging control method described in the above technical solution.

[0036] The charging control method provided in the present application monitors the working state of the battery pack in the energy storage device when it is detected that the energy storage device is connected to an external power supply. When it is detected that the working state of the battery pack is switched from the charging state to the standby state, it indicates that the battery pack has stopped charging, that is, the charging circuit of the battery pack may have actually been disconnected. At this time, the voltage parameters and charging protection parameters of the battery pack are obtained. From the charging protection parameters, it can be determined whether the charging is stopped because the battery pack triggers a preset protection condition during the charging process, that is, whether the charging stop is triggered by software. When the voltage parameter of the battery pack is greater than the preset voltage threshold, that is, the battery pack has a higher voltage and power at this time, and the charging protection parameter does not meet the preset protection condition, it can be determined that the reason why the battery pack stops charging is not the software protection caused by the triggering of the preset protection condition, but because the battery pack is already in a charging overvoltage state, which triggers the protection in the hardware, causing the charge and discharge circuit to be directly disconnected. At this time, a stop charging instruction is output to the power conversion circuit to control the power conversion circuit to stop outputting the charging current to the battery pack. In this way, the software also triggers the protection function synchronously, stopping the output of high current. This can avoid the situation where after the hardware protection function is restored and the battery pack charging circuit is restored, the power conversion board immediately outputs a large charging current to charge the battery pack because the software has not performed protection. This will cause the hardware protection function to be triggered again, and this cycle will be repeated, resulting in hiccups and repeated charging of the battery pack.

[0037] In this way, the charging control method provided in the present application monitors the state transitions of the battery pack during the charging process, and determines whether the battery pack charging circuit has been disconnected due to overvoltage based on the voltage parameters and charging protection parameters of the battery pack. If so, the charging current output to the battery pack is stopped, thereby avoiding the battery pack from being repeatedly charged in an overvoltage state.

[0038] It should be understood that the foregoing general description and the following detailed description are merely illustrative and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0040] Figure 1 A schematic diagram of an application environment of the technical solution of an embodiment of the present application is shown.

[0041] Figure 2 A flowchart of the steps of a charging control method in one embodiment of the present application is shown.

[0042] Figure 3 The structural block diagram of the charging control device provided in an embodiment of the present application is schematically shown.

[0043] Figure 4 The structural block diagram of the power conversion device provided in an embodiment of the present application is schematically shown.

[0044] Figure 5 The following schematically shows a block diagram of a computer system structure of an electronic device suitable for implementing an embodiment of the present application. DETAILED DESCRIPTION

[0045] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art.

[0046] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner.In the following description, many specific details are provided so as to provide a full understanding of the embodiments of the present application. However, it will be appreciated by those skilled in the art that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps etc. can be adopted. In other cases, known methods, devices, implementations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0047] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically separate entities. That is, these functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0048] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all content and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, while others may be combined or partially combined. Therefore, the actual execution order may vary depending on the actual situation.

[0049] The following describes in detail the technical solutions such as the charging control method, device, power conversion device, and storage medium provided in this application in conjunction with specific implementation methods.

[0050] Figure 1 The following is a schematic diagram showing an application environment of the technical solution of the embodiment of the present application. Figure 1 As shown, the battery pack 10 discharges to the outside through the power conversion circuit 40 or receives charging from the external power source 30. The battery pack 10 is generally further provided with a BMS board 20 for managing the charge and discharge of the battery pack.

[0051] like Figure 1 As shown, the battery pack 10 includes a plurality of battery cells 11. For example, the battery cells 11 can be connected in series to form the battery pack 10. It is understood that the battery cells 11 can also be connected in parallel or in other combinations to form a battery pack, which is not limited in this application.

[0052] The BMS board 20 electrically connected to the battery pack is generally arranged adjacent to the battery pack or encapsulated in the battery pack. The BMS board 20 includes a charging switch tube 22 and / or a discharging switch tube 22 arranged on the discharge circuit of the battery pack, that is, the charging and discharging switch tube 22. For example, Figure 1 As shown, the charge and discharge switch tube 22 can be a MOS tube (Metal-Oxide-SemiconductorField-Effect Transistor, MOSFET, metal oxide semiconductor field effect transistor). In other embodiments, it can also be other devices with switching functions, such as IGBT tubes (Insulated Gate Bipolar Transistor) or triodes, etc. The BMS board 20 is also provided with an AFE chip 21 (analog front end) 21 for detecting battery charging parameters, for example, for collecting the voltage, current temperature, and temperature of the charge and discharge switch tube 22 of each battery cell in the battery pack, and controlling the on or off of the charge and discharge switch tube 22. It can be understood that the analog front end chip 21 can accurately detect different charging parameters of the battery pack 10 on the BMS board 20. For example, the voltage, current, and temperature of the charge and discharge switch tube 22 of a single battery cell 11.

[0053] The power conversion circuit 40 can be located on a circuit board and performs voltage conversion functions, such as AC-DC or DC-DC conversion, to charge the battery pack 10 or discharge the battery pack 10. The battery pack 10 discharges and receives charge via the switching transistor 220 on the BMS board 20 and the power conversion circuit 40. The external power source 30 charges the battery pack 10 through the power conversion circuit 40. The circuit board where the power conversion circuit 40 is located can include an interface for connecting to the external power source 30.

[0054] It is understood that the power conversion circuit 40, BMS board 20, and battery pack 10 described above can be integrated into the same device to form an energy storage device, or they can be independent devices forming an energy storage system. For example, the BMS board 20 and battery pack 10 can form an independent battery device, and the circuit board where the power conversion circuit 40 is located can be an independent inverter device. The inverter device is provided with different interfaces for connecting to the battery device, other external power sources, and loads. The battery device is connected to the inverter device, and the inverter device supplies power to the load or receives charging from an external power source. Thus, the external power source, inverter device, and battery device form an energy storage system.

[0055] It can be understood that the power conversion circuit 40 further includes a controller ( Figure 1 (not shown) for executing the charging control method of each embodiment of the present application.

[0056] It is understood that in other embodiments, the power conversion circuit 40 may also be disposed on different circuit boards. For example, the circuits related to the AC-DC conversion portion may be disposed on a first circuit board to implement the AC-DC conversion function, while the circuits related to the DC-DC conversion portion may be disposed on a second circuit board to implement the DC conversion function. Alternatively, other arrangements may be employed, and this application is not limited thereto.

[0057] It should be noted that in relevant battery technologies, the overvoltage information of the battery cells of the battery pack 10 energy storage device during the charging process is often not detected synchronously by the software, such as the controller, and the hardware circuit directly set on the battery pack 10, resulting in the energy storage device battery pack being repeatedly charged in an overvoltage state. For example, the hardware overvoltage point of a single battery cell is 3.65V, while the software overvoltage point is 3.63V. Since the AFE chip on the BMS circuit board can directly detect the voltage of a single battery cell, when the BMS circuit board detects that the voltage of any battery cell exceeds 3.65V, it will trigger the hardware overvoltage protection and stop charging. As for software protection, the control chip can only detect the voltage at the P+ of the power conversion circuit 40 energy storage device as the total voltage of the battery pack 10 energy storage device, and then obtain the average voltage through the total voltage and the number of battery cells of the energy storage device, and judge whether the battery pack 10 energy storage device is overvoltage based on the average voltage. The battery pack 10 energy storage device often has unbalanced cell voltages during charging. Therefore, the voltage of a certain cell may exceed 3.65V, while the average voltage detected by the control chip has not reached 3.63V. Therefore, the control chip will not trigger the charging completion instruction. This causes the power conversion circuit 40 to continue to repeatedly charge the battery pack 10 energy storage device with a large current after the hardware overvoltage protection is released, thereby causing damage to the battery pack 10 energy storage device.

[0058] In order to solve the above problems, Figure 2 A flowchart showing the steps of a charging control method in one embodiment of the present application is shown in FIG. Figure 2 As shown, the charging control method is applied to a controller, which is provided on a power conversion circuit. The power conversion circuit is connected to both ends of the battery pack. The battery pack discharges or receives charge through the power conversion circuit. The charging control method may mainly include the following steps S100 to S400. Each step of the charging control method is described in detail below.

[0059] Step S100: Acquire the connection status of the external power supply.

[0060] Specifically, the purpose of the technical solution of this application is to avoid the situation where the battery pack has reached an overvoltage state and is still repeatedly input with high-power current during the charging process. Therefore, it is necessary to obtain the access status of the external power supply, that is, the battery pack can only be overvoltage charged when the energy storage device is connected to the external power supply.

[0061] It is understood that the above energy storage device may include Figure 1 The power conversion circuit 40, the BMS board 20 and the battery pack 10 are shown. In other embodiments, the solution can also be executed by an independent device where the power conversion circuit 40 is located, and this application does not limit this.

[0062] The connection status of the external power supply can be determined by detecting the connection of the external power supply. For example, as described above, a first interface for connecting to the external power supply can be provided on the circuit board where the power conversion circuit is located, and whether the external power supply is connected can be determined by detecting a change in the voltage at the first interface.

[0063] Step S200: When the access status indicates that an external power source is connected, the working status of the battery pack is monitored.

[0064] When it is detected that the power conversion circuit is connected to an external power supply, the working state of the battery pack is monitored. Among them, the working state includes charging state, standby state and discharging state. The charging state is the state when the battery pack obtains electric energy from the external power supply through the power conversion circuit, the discharging state is the state when the battery pack releases electric energy to the external device through the power conversion circuit, and the standby state is the state when the battery pack neither obtains electric energy from the outside nor releases electric energy to the outside. The monitoring of the working state of the battery pack can be achieved by monitoring the current or voltage at the connection between the power conversion circuit and the battery pack. For example, it can be achieved by monitoring Figure 1 The voltage or current at P+ is shown.

[0065] Step S300 , when it is monitored that the working state is switched from the charging state to the standby state, the voltage parameters and the charging protection parameters of the battery pack are obtained.

[0066] When the working state of the battery pack is monitored to switch from the charging state to the standby state, it means that the battery pack has stopped charging. At this time, the voltage parameters and charging protection parameters of the battery pack are obtained. Among them, the voltage parameters can measure the current charging state of the battery pack, for example, whether it is fully charged. For the battery pack, a voltage threshold can be set. When the voltage of the battery pack reaches this voltage threshold, it means that the battery pack is nearly fully charged. When the battery pack voltage exceeds this voltage threshold, it is considered that the battery pack is in an overvoltage state. It is understandable that for software overvoltage protection, since the single cell voltage of each battery cell in the battery pack cannot be directly obtained, the above voltage parameter can be the average voltage of the battery cells in the battery pack. The charging protection parameters are used to determine whether the preset protection condition is triggered because the battery pack is in an abnormal state during the charging process, thereby causing the battery pack to stop charging. Charging protection parameters include but are not limited to the overcurrent protection value, overvoltage protection value, and overtemperature protection value of the battery pack during the charging process.

[0067] In step S400 , when the voltage parameter is greater than the preset voltage threshold and the charging protection parameter does not meet the preset protection condition, a stop charging instruction is output to the power conversion circuit to control the power conversion circuit to stop outputting the charging current to the battery pack.

[0068] Specifically, when the voltage parameter of the battery pack is greater than a preset voltage threshold, a cell in the battery pack may be in an overvoltage state. Here, the preset voltage threshold is less than the voltage protection threshold in the preset protection condition, that is, less than the overvoltage protection value at which the controller triggers the battery pack overvoltage protection.

[0069] Under the above premise, if the charging protection parameters do not meet the preset protection conditions, it can be determined that the reason why the battery pack stops charging is not because the preset protection conditions are triggered, but because the overvoltage triggers the hardware protection, indicating that the battery pack is already in a charging overvoltage state.

[0070] At this time, a stop charging instruction is output to the power conversion circuit to control the power conversion circuit to stop outputting charging current to the battery pack. This can avoid the situation where after the hardware protection is restored and the battery pack charging circuit is restored, the power conversion circuit immediately outputs a large charging current to the battery pack for charging due to the lack of software protection, which triggers the hardware protection again. This is repeated, resulting in hiccups and causing the battery pack to be charged repeatedly.

[0071] The charging control method provided in the present application monitors the working state of the battery pack in the energy storage device when it is detected that the energy storage device is connected to an external power supply. When it is detected that the working state of the battery pack is switched from the charging state to the standby state, it indicates that the battery pack has stopped charging, that is, the charging circuit of the battery pack may have actually been disconnected. At this time, the voltage parameters and charging protection parameters of the battery pack are obtained. From the charging protection parameters, it can be determined whether the charging is stopped because the battery pack triggers a preset protection condition during the charging process, that is, whether the charging stop is triggered by software. When the voltage parameter of the battery pack is greater than the preset voltage threshold, that is, the battery pack has a higher voltage and power at this time, and the charging protection parameter does not meet the preset protection condition, it can be determined that the reason why the battery pack stops charging is not the software protection caused by the triggering of the preset protection condition, but because the battery pack is already in a charging overvoltage state, which triggers the protection in the hardware, causing the charge and discharge circuit to be directly disconnected. At this time, a stop charging instruction is output to the power conversion circuit to control the power conversion circuit to stop outputting the charging current to the battery pack. In this way, the protection is also triggered synchronously from the software to stop outputting high current. This can avoid the situation where after the hardware protection is restored and the battery pack charging circuit is restored, the power conversion board immediately outputs a large charging current to charge the battery pack because the software has not performed protection, which causes the hardware protection to be triggered again. This is repeated, resulting in hiccups and causing the battery pack to be repeatedly charged.

[0072] In this way, the charging control method provided in the present application monitors the state transitions of the battery pack during the charging process, and determines whether the battery pack charging circuit has been disconnected due to overvoltage based on the voltage parameters and charging protection parameters of the battery pack. If so, the charging current output to the battery pack is stopped, thereby avoiding the battery pack from being repeatedly charged in an overvoltage state.

[0073] Furthermore, based on the above embodiment, the voltage parameter is the average voltage of the battery cells, and the battery pack includes multiple battery cells. The above step S300 of obtaining the voltage parameter of the battery pack includes the following steps S301 and S302.

[0074] Step S301: Detect the current total voltage of the battery pack.

[0075] Step S302 : Calculate the average cell voltage according to the current total voltage of the battery pack and the number of cells.

[0076] Specifically, the protection measures used to prevent the battery pack of the energy storage device from being over-charged include software protection and hardware protection, both of which trigger overvoltage protection when the voltage of a single cell in the battery pack is greater than the overvoltage protection value. Figure 2 As shown, since the power conversion circuit that performs software protection can only detect the total voltage of the battery pack at P+, the voltage parameter used by the controller to determine whether the battery pack is over-voltage can only be the average parameter calculated based on the total voltage, rather than the directly measured single-cell voltage. Hardware protection is to directly detect the voltage of a single cell by the sensor. As long as a single cell overvoltage occurs, it is determined that the battery pack has reached an overvoltage state. It can be understood that since the hardware device that performs hardware protection is, for example, Figure 1 The BMS board shown is directly connected to the battery pack, and its AFE chip can be directly set at each cell of the battery pack, so the voltage of a single cell in the battery pack can be accurately detected.

[0077] Furthermore, based on the above embodiment, the charging protection parameters include battery charging parameters and charging fault parameters. Acquiring the charging protection parameters of the battery pack in the above step S300 includes the following steps S303 to S305.

[0078] Step S303 , detecting the charging temperature and charging current of the battery pack during the charging process to determine the battery charging parameters.

[0079] Specifically, during the charging process of the battery pack, whether the battery pack is in a normal charging state is determined by detecting the temperature at P+ on the power conversion circuit provided with a controller and the magnitude of the output charging current.

[0080] It can be understood that the magnitude of the charging current at B+ on the BMS board is substantially the same as the magnitude of the charging current at P+ on the power conversion circuit and the temperature.

[0081] Step S304: detecting the working state of the power conversion circuit board to determine the charging fault parameter.

[0082] Specifically, by detecting the working status of the power conversion circuit, such as detecting whether the conversion circuit in the power conversion circuit, such as the inverter, has excessive current / excessive temperature during the charging process, or fan stalling, or bus overvoltage, etc., it can be determined whether the battery pack stops charging due to a power conversion circuit failure.

[0083] Step S305 , when the charging fault parameter matches the preset fault code, or when the battery charging parameter is greater than or equal to the preset charging protection threshold, confirming that the charging protection parameter meets the preset protection condition.

[0084] Specifically, when the controller detects excessive current or temperature in the power conversion circuit during charging, fan stall, or bus overvoltage, it generates a preset fault code corresponding to the aforementioned fault condition. Based on the preset fault code, it can be determined that the battery pack stopped charging because a preset protection condition was met, namely, hardware protection was triggered by an inverter fault. Alternatively, if the battery pack is detected to be overheated or the charging current is too high during charging, the preset protection condition is also met, namely, charging protection is triggered by an abnormal charging state of the power conversion circuit or battery pack.

[0085] In this way, this embodiment traverses the situations that cause the battery pack to stop charging according to the charging temperature, charging current and working status of the inverter during the charging process. That is to say, if the above situations meet the preset protection conditions, the protection will be triggered to cause the battery pack to stop charging. Only when the preset protection conditions are not met, it is possible that the hardware protection is triggered due to the overvoltage state, cutting off the charging circuit and causing charging to stop.

[0086] Furthermore, based on the above embodiments, in the above step S400, when the voltage parameter is greater than the preset voltage threshold and the charging protection parameter does not meet the preset protection condition, a stop charging instruction is output to the power conversion circuit to control the power conversion circuit to stop outputting the charging current to the battery pack, including the following steps S401 and S402.

[0087] Step S401: Obtain overvoltage detection duration.

[0088] In step S402 , if the voltage parameter is continuously greater than the preset threshold value and the charging protection parameter continuously fails to meet the preset protection condition during the overvoltage detection period, a stop charging instruction is output to the power conversion circuit to control the power conversion circuit to stop outputting the charging current to the battery pack.

[0089] Specifically, if the average cell voltage of the battery pack continuously reaches a preset threshold for a certain period of time and none of the above-mentioned preset protection conditions are met, it can be determined that the battery pack has reached an overvoltage state, triggering hardware protection, causing the battery pack to stop charging. It is understood that the above-mentioned time period can be 2 seconds, 5 seconds, or 8 seconds, etc., and is not specifically limited here.

[0090] This embodiment limits the overvoltage detection time of the battery pack to avoid the situation where the battery pack is mistakenly judged as overvoltage and charging is stopped due to voltage fluctuations of the battery pack during the charging process when the overvoltage detection time is too short. It also avoids the situation where the power conversion circuit cannot be controlled in time to stop outputting the charging current when the overvoltage detection time is too long, resulting in the battery pack repeatedly receiving excessive charging current in an overvoltage state.

[0091] Furthermore, based on the above embodiment, after executing the stop charging instruction in the above step S400 to stop outputting the charging current to the battery pack, the method further includes the following step S403.

[0092] Step S403 : Assigning the state of charge of the battery pack to a fully charged state. The state of charge is used to reflect the remaining power of the battery pack.

[0093] Specifically, because the hardware protection triggered by overvoltage, directly detecting the battery pack's voltage parameters through sensors, responds faster than the software protection implemented by the controller, when the controller determines that the battery pack has stopped charging due to overvoltage triggering hardware protection, it indicates that the battery pack is fully charged. At this point, assigning the battery pack's state of charge from a partially charged state to a fully charged state provides a more accurate state of charge display and improves the user experience.

[0094] Furthermore, based on the above embodiment, after assigning the state of charge of the battery pack to a fully charged state according to the stop charging instruction in the above step S403, the method further includes the following step S404.

[0095] In step S404 , when it is detected that the external power source is disconnected and then reconnected, and the state of charge of the battery pack is lower than a preset power threshold, a charging instruction is output to the power conversion circuit to control the power conversion circuit to output a charging current to the battery pack.

[0096] Specifically, if the energy storage device is disconnected from the external power source while being connected, and is reconnected to the external power source after a period of time, and the battery pack's state of charge falls below a preset power threshold, the energy storage device is deemed to have undergone a certain amount of energy consumption. At this point, the battery pack in the energy storage device is no longer fully charged and can therefore be recharged. A charging instruction is then output to the power conversion circuit, which controls the power conversion circuit to output a charging current to the battery pack for charging. The preset power threshold can be 98%, 95%, or 90% of a full charge, for example, and is not specifically limited here.

[0097] In this way, this embodiment provides specific limiting conditions for resuming charging after the battery pack stops charging due to overvoltage triggering hardware protection, thereby avoiding the situation where the energy storage device is continuously connected to the external power supply and is immediately input with a high-power charging current after being discharged due to some reasons in the battery pack, thereby causing damage to the battery pack.

[0098] Furthermore, based on the above embodiment, monitoring the working status of the battery pack in the above step S100 includes the following steps S101 to S104.

[0099] Step S101: obtaining a current sampling value collected by a sampling device.

[0100] Step S102 : comparing the current sampling value with a preset current threshold range.

[0101] Step S103 : If the current sampling value is within the preset current threshold range, it is determined that the battery pack is in the standby state.

[0102] In step S104 , if the current sampling value is greater than the maximum value of the preset current threshold range, it is determined that the battery pack is in a charging state.

[0103] Specifically, a sampling device is provided on the power conversion circuit board, and is used to sample the current output from the power conversion circuit board to the battery pack. The current input to the battery pack through the charge and discharge switch is sampled by the sampling device provided on the power conversion circuit board. If the current sampling value is within the preset current threshold range, it is determined that the battery pack is in a standby state, that is, the battery pack is not charging at this time. Exemplarily, the preset current threshold range can be between -1A and 1A, which can be determined based on the characteristics of the battery cell and the sampling device of the battery pack, and is not specifically limited here. If the current sampling value is greater than 1A, it is determined that the battery pack is in a charging state and is obtaining electrical energy through the charge and discharge switch tube. The preset current threshold range is used to avoid the battery pack being mistakenly judged as being in a charging state due to current sampling errors, that is, under normal circumstances, even if the battery pack is in a standby state, the sampling device will detect a certain current value due to sampling errors.

[0104] In addition, in other feasible embodiments, the sampling current can be obtained by collecting the voltage drop on the sampling resistor provided in the power conversion circuit and connected to the battery pack through a voltage sensor, and then calculating the current flowing through the sampling resistor based on the voltage drop.

[0105] The following introduces an embodiment of a device of the present application, which can be used to execute the charging control method in the above-mentioned embodiment of the present application. Figure 3 The structural block diagram of the charging control device provided by the embodiment of the present application is schematically shown. The above device is set in the controller. Figure 3 As shown, the charging control device 300 includes:

[0106] The first acquisition module 310 is configured to acquire the connection status of the external power source.

[0107] The monitoring module 320 is configured to monitor the working state of the battery pack when the access state indicates that an external power source is connected, where the working state includes a charging state and a standby state.

[0108] The second acquisition module 330 is configured to acquire the voltage parameters and charging protection parameters of the battery pack when it is detected that the working state is switched from the charging state to the standby state.

[0109] The charging control module 340 is configured to output a stop charging instruction to the power conversion circuit when the voltage parameter is greater than a preset voltage threshold and the charging protection parameter does not meet the preset protection condition, so as to control the power conversion circuit to stop outputting the charging current to the battery pack.

[0110] In one embodiment of the present application, based on the above embodiment, the second acquisition module includes:

[0111] The voltage acquisition unit is configured to detect the current total voltage of the battery pack; and calculate the average voltage of the battery cells according to the current total voltage of the battery pack and the number of battery cells.

[0112] In one embodiment of the present application, based on the above embodiment, the second acquisition module further includes:

[0113] The charging protection parameter acquisition module is configured to detect the charging temperature and charging current of the battery pack during the charging process to determine the battery charging parameters; and to detect the working status of the power conversion circuit board to determine the charging fault parameters; wherein, when the charging fault parameters match the preset fault code, or when the battery charging parameters are greater than or equal to the preset charging protection threshold, it is confirmed that the charging protection parameters meet the preset protection conditions.

[0114] In one embodiment of the present application, based on the above embodiment, the charging control module 340 includes:

[0115] A detection duration acquisition unit is configured to acquire an overvoltage detection duration;

[0116] The charging control unit is configured to output a stop charging instruction to the power conversion circuit to control the power conversion circuit to stop outputting charging current to the battery pack if the voltage parameter continues to be greater than the preset threshold and the charging protection parameter continues to fail to meet the preset protection conditions within the overvoltage detection period.

[0117] In one embodiment of the present application, based on the above embodiment, the charging control module 340 further includes:

[0118] The assignment unit is configured to assign the state of charge of the battery pack to a fully charged state, where the state of charge is used to reflect the remaining power of the battery pack.

[0119] In one embodiment of the present application, based on the above embodiment, the charging control module 340 further includes:

[0120] The instruction output unit is configured to output a charging instruction to the power conversion circuit to control the power conversion circuit to output a charging current to the battery pack when it detects that the external power supply is disconnected and then reconnected and the charge state of the battery pack is lower than a preset power threshold.

[0121] In one embodiment of the present application, based on the above embodiment, the monitoring module 320 includes:

[0122] A current sampling unit is configured to obtain a current sampling value collected by a sampling device, the sampling device is provided on the power conversion circuit board, and is used to sample the current output from the power conversion circuit board to the battery pack;

[0123] The current comparison unit is configured to compare the current sampling value with a preset current threshold range; if the current sampling value is within the preset current threshold range, it is determined that the battery pack is in a standby state; if the current sampling value is greater than the maximum value of the preset current threshold range, it is determined that the battery pack is in a charging state.

[0124] This application also provides a power conversion device that can be used to implement the charging control method described in the above embodiments of this application. The power conversion device includes a power conversion circuit and a first interface, wherein the first interface is configured to connect to a battery pack. The power conversion device also includes a memory, a processor, and a battery pack charging control program stored in the memory and executable by the processor. When executed by the processor, the charging control program implements the charging control method described in the above embodiments.

[0125] like Figure 4As shown, the power conversion device 400 includes a power conversion circuit 410, a memory 420, a processor 430 and a first interface 440. The first interface 440 can be used to connect to the battery pack. In addition, the power conversion device 400 can also include a second interface ( Figure 4 (not shown) for accessing an external power source to charge the battery pack.

[0126] It can be understood that in this embodiment, the battery pack can be integrated with Figure 1 The battery pack 10 of the BMS board shown includes a plurality of battery cells 11 and a BMS board 20 .

[0127] It is understood that the power conversion circuit 410 can be as follows Figure 1 The power conversion circuit, processor 430 and memory 420 shown can be arranged on the circuit board where the power conversion circuit is located, or can be arranged on other circuit boards in the energy storage device.

[0128] It is understandable that the power conversion device 400 may include more or fewer modules. For example, the power conversion device 400 may also include a battery pack, and this application does not impose any restrictions on this.

[0129] The present application also provides an electronic device, which may be an energy storage device including the power conversion device.

[0130] Figure 5 The block diagram schematically shows a computer system structure of an electronic device used to implement an embodiment of the present application.

[0131] It should be noted that Figure 5 The computer system 500 of the electronic device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0132] It should be noted that Figure 5 The computer system 500 of the electronic device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0133] like Figure 5As shown, the computer system 500 includes a central processing unit (CPU) 501, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) 502 or the program loaded from the storage part 508 into the random access memory (RAM) 503. Various programs and data required for system operation are also stored in the random access memory 503. The CPU 501, the read-only memory 502, and the random access memory 503 are connected to each other via a bus 504. An input / output interface 505 (i.e., an I / O interface) is also connected to the bus 504.

[0134] The following components are connected to the input / output interface 505: an input section 506 including a keyboard, a mouse, and the like; an output section 507 including devices such as a cathode ray tube (CRT), a liquid crystal display (LCD), and speakers; a storage section 508 including a hard disk; and a communication section 509 including a network interface card such as a local area network card or a modem. The communication section 509 performs communication processing via a network such as the Internet. A drive 510 is also connected to the input / output interface 505 as needed. Removable media 511, such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, is installed in the drive 510 as needed, so that computer programs read therefrom can be installed into the storage section 508 as needed.

[0135] In particular, according to embodiments of the present application, the processes described in the various method flowcharts can be implemented as computer software programs. For example, embodiments of the present application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for executing the methods illustrated in the flowcharts. In such embodiments, the computer program can be downloaded and installed over a network and / or installed from removable media. When executed by a processor, the computer program performs the various functions defined in the charging control device or power conversion device of the present application.

[0136] It should be noted that the computer-readable medium shown in the embodiments of the present application may be a computer-readable signal medium or a computer-readable storage medium or any combination of the two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or component, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a flash memory, an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, device or device. In the present application, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries a computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, or any suitable combination thereof.

[0137] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, program segment, or a part of code, and the above-mentioned module, program segment, or a part of code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0138] It should be noted that although several modules or units of the device for action execution are mentioned in the detailed description above, this division is not mandatory. In fact, according to the embodiment of the application, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided into multiple modules or units to be embodied.

[0139] Through the description of the above embodiments, it is easy for those skilled in the art to understand that the example embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, and includes a number of instructions to enable a computing device (which can be a personal computer, a server, a touch terminal, or a network device, etc.) to execute the method according to the embodiments of the present application.

[0140] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of this application and include common knowledge or customary techniques in the art that are not disclosed herein.

[0141] It should be understood that the present application is not limited to the exact structures described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A charging control method, applied to a controller, characterized in that: The controller is provided on a power conversion circuit, the power conversion circuit is connected to both ends of the battery pack, and the battery pack is discharged or charged via the power conversion circuit. The charging control method includes: Get the access status of the external power supply; When the access status indicates that the external power source is connected, monitoring the working status of the battery pack, the working status including a charging state and a standby state; When it is monitored that the working state is switched from the charging state to the standby state, obtaining voltage parameters and charging protection parameters of the battery pack; When the voltage parameter is greater than a preset voltage threshold and the charging protection parameter does not meet a preset protection condition, outputting a stop charging instruction to the power conversion circuit to control the power conversion circuit to stop outputting charging current to the battery pack; The battery pack includes multiple battery cells, the voltage parameter is the average voltage of the battery cells, the charging protection parameter includes a battery charging parameter and a charging fault parameter, and obtaining the voltage parameter and charging protection parameter of the battery pack includes: Detecting the current total voltage of the battery pack; Calculating the average voltage of the battery cells according to the current total voltage of the battery pack and the number of the battery cells; detecting a charging temperature and a charging current of the battery pack during charging to determine charging parameters of the battery; detecting the operating state of the power conversion circuit to determine the charging fault parameter; When the charging fault parameter matches a preset fault code, or when the battery charging parameter is greater than or equal to a preset charging protection threshold, it is confirmed that the charging protection parameter meets the preset protection condition.

2. The charging control method according to claim 1, wherein: When the voltage parameter is greater than a preset voltage threshold and the charging protection parameter does not meet a preset protection condition, outputting a stop charging instruction to the power conversion circuit to control the power conversion circuit to stop outputting a charging current to the battery pack, including: Get the overvoltage detection duration; During the overvoltage detection time, if the voltage parameter continues to be greater than the preset voltage threshold and the charging protection parameter continues to fail to meet the preset protection condition, the stop charging instruction is output to the power conversion circuit to control the power conversion circuit to stop outputting charging current to the battery pack.

3. The charging control method according to claim 1, wherein: After executing the stop charging instruction to stop outputting the charging current to the battery pack, the method further includes: The state of charge of the battery pack is assigned to a fully charged state, where the state of charge is used to reflect the remaining power of the battery pack.

4. The charging control method according to claim 3, wherein: After assigning the state of charge of the battery pack to a fully charged state, the method further includes: When it is detected that the external power supply is disconnected and then reconnected, and the state of charge of the battery pack is lower than a preset power threshold, a charging instruction is output to the power conversion circuit to control the power conversion circuit to output a charging current to the battery pack.

5. The charging control method according to claim 1, wherein: The monitoring of the working status of the battery pack includes: Acquiring a current sampling value collected by a sampling device, wherein the sampling device is provided on a power conversion circuit board and is used to sample the current output from the power conversion circuit board to the battery pack; Comparing the current sampling value with a preset current threshold range; If the current sampling value is within the preset current threshold range, determining that the battery pack is in a standby state; If the current sampling value is greater than the maximum value of the preset current threshold range, it is determined that the battery pack is in a charging state.

6. A charging control device, characterized in that: The charging control device includes: A first acquisition module is configured to acquire a connection status of an external power source; a monitoring module configured to monitor the working state of the battery pack when the access state indicates that the external power source is connected, wherein the working state includes a charging state and a standby state; a second acquisition module, configured to acquire a voltage parameter and a charging protection parameter of the battery pack when monitoring that the working state is switched from the charging state to the standby state; a charging control module configured to output a charging stop instruction to the power conversion circuit when the voltage parameter is greater than a preset voltage threshold and the charging protection parameter does not meet a preset protection condition, so as to control the power conversion circuit to stop outputting a charging current to the battery pack; The battery pack includes a plurality of battery cells, the voltage parameter is the average voltage of the battery cells, the charging protection parameter includes a battery charging parameter and a charging fault parameter, and the second acquisition module includes: a voltage acquisition unit configured to detect a current total voltage of the battery pack; and calculate the average voltage of the battery cells according to the current total voltage of the battery pack and the number of the battery cells; A charging protection parameter acquisition module is configured to detect the charging temperature and charging current of the battery pack during the charging process to determine the battery charging parameters; and to detect the working state of the power conversion circuit to determine the charging fault parameters; wherein, when the charging fault parameters match a preset fault code, or when the battery charging parameters are greater than or equal to a preset charging protection threshold, it is confirmed that the charging protection parameters meet the preset protection conditions.

7. A power conversion device, characterized in that: The power conversion device includes a power conversion circuit and a first interface, wherein the first interface is used to access a battery pack. The power conversion device also includes a memory, a processor, and a charging control program for the battery pack stored in the memory and runnable on the processor. When the charging control program for the battery pack is executed by the processor, it implements the charging control method according to any one of claims 1 to 5.

8. A storage medium, characterized in that: The storage medium stores a computer program, which, when executed by a processor, implements the charging control method according to any one of claims 1 to 5.

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