Power battery charging method and system

Abstract

The invention discloses a power battery charging method and system. According to the technical scheme provided by the embodiment of the invention, during direct-current charging, the battery management system BMS communicates with the direct-current charging socket and the vehicle-mounted charger at the same time to perform charging configuration, that is, the direct-current charging pile connected with the direct-current charging socket is configured with the constant-voltage charging mode to output the direct-current charging voltage to the vehicle-mounted charger; the DC charging voltage is kept consistent with the rated working voltage of the vehicle-mounted charger, the DC / DC module of the vehicle-mounted charger is multiplexed through AC charging and DC charging, and under the condition that the DC / DC module is not additionally added, charging can be achieved through an AC charging pile and a DC charging pile, the cost of a battery system is effectively reduced, and the cost of the battery system is reduced. And the charging convenience is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power batteries, and in particular to a power battery charging method and system. Background Art

[0002] The main performance indicators of lithium-ion power batteries include safety, cycle life, energy density, operating temperature range, and charging speed. Energy density determines the range of a single full charge. After the past decade of development, it can now meet the 500-700 km range required for electric vehicles. The cycle life of the battery cell has been extended from the initial 1,000-plus to over 10,000. Safety performance has also been improved from a 5-minute warning of open flames to a prohibition of fire. Currently, the battery can be used in low-temperature conditions, with a 2C charge at -20°C. Although charging speeds can reach 5C or even 10C continuous fast charging, charging convenience remains an issue.

[0003] A00-class electric vehicles, as short-distance urban commuting vehicles, enjoy stable demand, particularly among young consumers and urban commuters. Most A00-class electric vehicles utilize low-voltage battery systems, with a rated voltage of less than 200V. Therefore, they typically require AC slow charging, rather than DC fast charging.

[0004] To address the charging convenience issue for A00-class electric vehicles, enabling them to be charged using both AC and DC charging stations, existing technologies require either the use of high-voltage batteries with a minimum voltage greater than 200V, or the configuration of a DC / DC converter module in addition to the onboard charger, or even a dedicated communication control module. These existing technologies suffer from poor charging convenience and high battery system costs. Summary of the Invention

[0005] The present invention provides a power battery charging method and system to solve the problems of poor charging convenience and high battery system cost in the prior art.

[0006] According to one aspect of the present invention, a power battery charging method is provided, which is performed by a power battery charging system. The system includes: a battery pack, an on-board charger, a battery management system, an AC charging socket, and a DC charging socket; the AC charging socket and the DC charging socket are respectively electrically connected to an AC / DC module and a DC / DC module within the on-board charger, and the on-board charger is electrically connected to the battery pack; the AC charging socket and the DC charging socket are also communicatively connected to the on-board charger, and the battery management system is respectively communicatively connected to the DC charging socket and the on-board charger; the method includes:

[0007] In a first charging mode, the battery management system sends a first battery charging voltage and a first battery maximum allowable charging current to the onboard charger. The first charging mode is a charging mode in which the AC charging socket is connected to an AC charging pile.

[0008] When the on-board charger detects the AC voltage of the power grid, determining the AC charging current of the battery pack according to the maximum allowable charging current of the first battery and the rated current of the on-board charger;

[0009] The on-board charger converts the grid AC voltage into the first battery charging voltage, and charges the battery pack according to the first battery charging voltage and the AC charging current;

[0010] In the second charging mode, the battery management system obtains the rated operating voltage of the on-board charger and sends the rated operating voltage to the DC charging pile connected to the DC charging socket, so that the DC charging pile is configured to output a DC charging voltage to the on-board charger in a constant voltage charging mode, and the DC charging voltage is consistent with the rated operating voltage of the on-board charger; the second charging mode is a charging mode in which the DC charging socket is connected to the DC charging pile;

[0011] The battery management system sends a second battery charging voltage and a second battery maximum allowable charging current to the on-board charger;

[0012] The on-board charger determines the DC charging current of the battery pack according to the maximum allowable charging current of the second battery and the rated current of the on-board charger;

[0013] The on-board charger converts the DC charging voltage into the second battery charging voltage, and charges the battery pack according to the second battery charging voltage and the DC charging current.

[0014] Optionally, when the on-board charger detects the AC voltage of the power grid, determining the AC charging current of the battery pack according to the maximum allowable charging current of the first battery and the rated current of the on-board charger includes:

[0015] When the on-board charger detects an AC voltage from a power grid, comparing the maximum allowable charging current of the first battery with the rated current of the on-board charger to obtain a first comparison result;

[0016] The on-board charger determines the AC charging current of the battery pack according to the first comparison result.

[0017] Optionally, the on-board charger determining the AC charging current of the battery pack according to the first comparison result includes:

[0018] If the first comparison result is that the maximum allowable charging current of the first battery is greater than or equal to the rated current of the on-board charger, the on-board charger uses the rated current of the on-board charger as the AC charging current of the battery pack;

[0019] If the first comparison result is that the maximum allowable charging current of the first battery is less than the rated current of the on-board charger, the on-board charger uses the maximum allowable charging current of the first battery as the AC charging current of the battery pack.

[0020] Optionally, determining the DC charging current of the battery pack by the on-board charger according to the maximum allowable charging current of the second battery and the rated current of the on-board charger includes:

[0021] comparing, at the on-board charger, the maximum allowable charging current of the second battery and the rated current of the on-board charger to obtain a second comparison result;

[0022] The on-board charger determines a DC charging current of the battery pack according to the second comparison result.

[0023] Optionally, the on-board charger determining the DC charging current of the battery pack according to the second comparison result includes:

[0024] If the second comparison result is that the maximum allowable charging current of the second battery is greater than or equal to the rated current of the on-board charger, the on-board charger uses the rated current of the on-board charger as the DC charging current of the battery pack;

[0025] If the second comparison result is that the maximum allowable charging current of the second battery is less than the rated current of the on-board charger, the on-board charger uses the maximum allowable charging current of the second battery as the DC charging current of the battery pack.

[0026] Optionally, in the first charging mode, before the battery management system sends the first battery charging voltage and the first battery maximum allowable charging current to the onboard charger, the method further includes:

[0027] detecting a first connection signal of the AC charging socket and a second connection signal of the DC charging socket, wherein the first connection signal is a signal when the AC charging socket is connected to an AC charging plug, and the second connection signal is a signal when the DC charging socket is connected to a DC charging plug;

[0028] A charging mode of the battery pack is determined according to the first connection signal or the second connection signal.

[0029] Optionally, determining a charging mode of the battery pack according to the first connection signal or the second connection signal includes:

[0030] When the first connection signal of the AC charging socket is detected, the charging mode of the battery pack is the first charging mode;

[0031] When the second connection signal of the DC charging socket is detected, the charging mode of the battery pack is the second charging mode.

[0032] Optionally, after the on-board charger converts the grid AC voltage into the first battery charging voltage and charges the battery pack according to the first battery charging voltage and the AC charging current, the method further includes:

[0033] When a charging termination condition is met, the on-board charger stops outputting the AC charging current to the battery pack based on a charging stop signal sent by the battery management system.

[0034] Optionally, after the on-board charger converts the DC charging voltage into the second battery charging voltage and charges the battery pack according to the second battery charging voltage and the DC charging current, the method further includes:

[0035] When a charging termination condition is met, the on-board charger stops outputting a DC charging current to the battery pack based on a charging stop signal sent by the battery management system.

[0036] According to another aspect of the present invention, a power battery charging system is provided, comprising: a battery pack, an onboard charger, a battery management system, an AC charging socket, and a DC charging socket; the AC charging socket and the DC charging socket are electrically connected to an AC / DC module and a DC / DC module within the onboard charger, respectively; the onboard charger is electrically connected to the battery pack; the AC charging socket and the DC charging socket are also communicatively connected to the onboard charger, and the battery management system is communicatively connected to the DC charging socket and the onboard charger, respectively;

[0037] In a first charging mode, the battery management system is used to send a first battery charging voltage and a first battery maximum allowable charging current to the on-board charger. The first charging mode is a charging mode in which the AC charging socket is connected to an AC charging pile.

[0038] The on-board charger is used to determine the AC charging current of the battery pack according to the maximum allowable charging current of the first battery and the rated current of the on-board charger when the AC voltage of the power grid is detected;

[0039] The on-board charger is further configured to convert the grid AC voltage into the first battery charging voltage, and charge the battery pack according to the first battery charging voltage and the AC charging current;

[0040] In the second charging mode, the battery management system is used to obtain the rated operating voltage of the on-board charger and send the rated operating voltage to the DC charging pile connected to the DC charging socket, so that the DC charging pile is configured to output a DC charging voltage to the on-board charger in a constant voltage charging mode, and the DC charging voltage is consistent with the rated operating voltage of the on-board charger; the second charging mode is a charging mode in which the DC charging socket is connected to the DC charging pile;

[0041] The battery management system is further configured to send a second battery charging voltage and a second battery maximum allowable charging current to the onboard charger;

[0042] The on-board charger is used to determine the DC charging current of the battery pack according to the maximum allowable charging current of the second battery and the rated current of the on-board charger;

[0043] The on-board charger is further configured to convert the DC charging voltage into the second battery charging voltage, and charge the battery pack according to the second battery charging voltage and the DC charging current.

[0044] An embodiment of the present invention provides a power battery charging method and system, the method comprising: in a first charging mode, a battery management system sends a first battery charging voltage and a first battery maximum allowable charging current to an on-board charger, the first charging mode being a charging mode in which an AC charging socket is connected to an AC charging pile; when the on-board charger detects the AC voltage of the power grid, the AC charging current of the battery pack is determined according to the first battery maximum allowable charging current and the rated current of the on-board charger; the on-board charger converts the AC voltage of the power grid into the first battery charging voltage, and charges the battery pack according to the first battery charging voltage and the AC charging current; in a second charging mode, the battery management system obtains the rated operating voltage of the on-board charger, And send the rated working voltage to the DC charging pile connected to the DC charging socket, so that the DC charging pile is configured to output a DC charging voltage to the on-board charger in a constant voltage charging mode, and the DC charging voltage is consistent with the rated working voltage of the on-board charger; the second charging mode is the charging mode in which the DC charging socket is connected to the DC charging pile; the battery management system sends the second battery charging voltage and the maximum allowable charging current of the second battery to the on-board charger; the on-board charger determines the DC charging current of the battery pack based on the maximum allowable charging current of the second battery and the rated current of the on-board charger; the on-board charger converts the DC charging voltage into the second battery charging voltage, and charges the battery pack according to the second battery charging voltage and the DC charging current. The technical solution of the embodiment of the present invention is that during DC charging, the battery management system BMS communicates with the DC charging socket and the on-board charger simultaneously to perform charging configuration. That is, the DC charging pile connected to the DC charging socket is configured in a constant voltage charging mode to output a DC charging voltage to the on-board charger, and the DC charging voltage is consistent with the rated operating voltage of the on-board charger. The DC / DC module of the on-board charger is reused through AC charging and DC charging. Without adding an additional DC / DC module, charging can be achieved using both AC charging piles and DC charging piles, effectively reducing the cost of the battery system and improving charging convenience.

[0045] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0047] Figure 1A flowchart of a power battery charging method provided by an embodiment of the present invention;

[0048] Figure 2 A schematic structural diagram of a power battery charging system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0049] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described 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 should fall within the scope of protection of the present invention.

[0050] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0051] Figure 1 This is a flowchart of a power battery charging method provided in an embodiment of the present invention. This embodiment is applicable to situations where A00-class electric vehicles can be charged using both AC charging piles and DC charging piles without increasing costs. The method can be executed by a power battery charging system. Figure 2 A schematic diagram of a power battery charging system according to an embodiment of the present invention is provided. Figure 2 The system includes: a battery pack 110, an onboard charger 120, a battery management system (BMS) 130, an AC charging socket 140, and a DC charging socket 150; the AC charging socket 140 and the DC charging socket 150 are respectively electrically connected to the AC / DC module and the DC / DC module inside the onboard charger 120, and the onboard charger 120 is electrically connected to the battery pack 110; the AC charging socket 140 and the DC charging socket 150 are also communicatively connected to the onboard charger 120, and the battery management system BMS 130 is respectively communicatively connected to the DC charging socket 150 and the onboard charger 120; wherein, Figure 2 Thick solid lines indicate electrical connections, and thin solid lines indicate communication connections. Figure 1 , the method comprising:

[0052] S110. In a first charging mode, the battery management system sends a first battery charging voltage and a first battery maximum allowable charging current to the onboard charger. The first charging mode is a charging mode in which an AC charging socket is connected to an AC charging pile.

[0053] The first battery charging voltage is the target charging voltage set by the BMS based on the battery's current state of charge, temperature, and other factors. This value is set in real time to prevent overcharging that could lead to battery damage or safety risks. The first battery's maximum allowable charging current is the upper limit of the charging current, adjusted in real time by the BMS based on the battery's current state of charge, temperature, and other factors. This is to prevent high-current charging from causing battery overheating, life degradation, or safety hazards.

[0054] Specifically, the battery management system (BMS) establishes communication with the onboard charger. The BMS sends the first battery charging voltage and the first battery's maximum allowable charging current to the onboard charger according to the charging MAP. The charging MAP is a mapping table that uses battery state parameters (such as SOC, temperature, and state of health (SOH)) as input dimensions and pre-sets optimal charging voltage, current, power, and other parameters. This table replaces a single fixed parameter and dynamically adjusts the charging strategy based on the battery's real-time status, taking into account charging efficiency, battery life, and safety.

[0055] S120 : When the on-board charger detects the AC voltage of the power grid, determine the AC charging current of the battery pack according to the maximum allowable charging current of the first battery and the rated current of the on-board charger.

[0056] Specifically, the onboard charger connects to the AC charging pile via the AC charging socket, confirms the charging plug is plugged in, establishes a communication channel between the vehicle charger and the AC charging pile, and establishes the AC power supply path. If the onboard charger can detect the AC grid voltage, it indicates that the AC charging socket has been confirmed to be plugged in and the onboard charger and the AC charging pile are connected. If the onboard charger cannot detect the AC grid voltage, it indicates that the AC charging socket has not established communication with the onboard charger and AC power is not connected. The AC charging socket and the onboard charger need to establish communication to connect AC power. If the onboard charger detects the AC grid voltage, it determines the relationship between the maximum allowable charging current of the first battery and the rated current of the onboard charger, and selects the minimum value as the AC charging current for the battery pack.

[0057] S130 : The on-board charger converts the AC voltage of the power grid into a first battery charging voltage, and charges the battery pack according to the first battery charging voltage and the AC charging current.

[0058] Specifically, the on-board charger first converts the grid AC voltage into an equivalent DC voltage of AC power through its internal AC / DC module, then converts the equivalent DC voltage into a first battery charging voltage through its internal DC / DC module, and finally charges the battery pack according to the first battery charging voltage and AC charging current.

[0059] S140. In the second charging mode, the battery management system obtains the rated operating voltage of the on-board charger and sends the rated operating voltage to the DC charging pile connected to the DC charging socket, so that the DC charging pile is configured to output a DC charging voltage to the on-board charger in a constant voltage charging mode, and the DC charging voltage is consistent with the rated operating voltage of the on-board charger; the second charging mode is a charging mode in which the DC charging socket is connected to the DC charging pile.

[0060] Specifically, the rated operating voltage of the onboard charger can be pre-stored as a hardware parameter in the BMS database or read in real time via the onboard charger's CAN bus. The battery management system (BMS) sends instructions to the DC charging pile connected to the DC charging socket via the CAN bus. The instructions include the rated operating voltage of the onboard charger and a constant voltage charging mode request. After receiving the instructions from the battery management system (BMS), the DC charging pile analyzes the rated operating voltage, adjusts the output voltage of the internal DC-DC converter to be consistent with the rated operating voltage, and outputs the DC charging voltage to the onboard charger. The purpose of keeping the DC charging voltage consistent with the rated operating voltage of the onboard charger is to protect the onboard charger and prevent the DC charging pile output voltage from exceeding the rated operating voltage of the onboard charger, causing the internal capacitor of the onboard charger to break down and easily causing a short circuit failure.

[0061] S150: The battery management system sends the second battery charging voltage and the second battery maximum allowable charging current to the onboard charger.

[0062] The second battery charging voltage and the second battery maximum allowable charging current have the same meaning as the first battery charging voltage and the first battery maximum allowable charging current in step S110, and are not further described here. The second battery charging voltage and the first battery charging voltage may be the same or different, and the second battery maximum allowable charging current may be the same or different from the first battery maximum allowable charging current, and the present invention is not limited thereto.

[0063] Specifically, the battery management system BMS establishes communication with the onboard charger, and the battery management system BMS sends the second battery charging voltage and the second battery maximum allowable charging current to the onboard charger according to the charging MAP table.

[0064] S160: The on-board charger determines a DC charging current for the battery pack according to the maximum allowable charging current of the second battery and the rated current of the on-board charger.

[0065] Specifically, the on-board charger determines the relationship between the maximum allowable charging current of the first battery and the rated current of the on-board charger, and selects the minimum value between the two as the DC charging current of the battery pack.

[0066] S170 : The on-board charger converts the DC charging voltage into a second battery charging voltage, and charges the battery pack according to the second battery charging voltage and the DC charging current.

[0067] Specifically, the on-board charger converts the DC charging voltage into the second battery charging voltage through the DC / DC module inside the on-board charger, and charges the battery pack according to the second battery charging voltage and the DC charging current.

[0068] The technical solution provided by the embodiment of the present invention, during DC charging, communicates with the DC charging socket and the on-board charger simultaneously through the battery management system (BMS) to perform charging configuration. That is, the DC charging pile connected to the DC charging socket is configured to output a DC charging voltage to the on-board charger in a constant voltage charging mode, and the DC charging voltage is consistent with the rated operating voltage of the on-board charger. The DC / DC module of the on-board charger is reused through AC charging and DC charging. Without adding an additional DC / DC module, charging can be achieved using both AC and DC charging piles, effectively reducing the cost of the battery system and improving charging convenience.

[0069] In other embodiments, optionally, step S120 specifically includes:

[0070] When the on-board charger detects the AC voltage of the power grid, the maximum allowable charging current of the first battery is compared with the rated current of the on-board charger to obtain a first comparison result.

[0071] The on-board charger determines the AC charging current of the battery pack according to the first comparison result.

[0072] Specifically, if the first comparison result is that the maximum allowable charging current of the first battery is greater than or equal to the rated current of the on-board charger, the on-board charger uses the rated current of the on-board charger as the AC charging current of the battery pack; if the first comparison result is that the maximum allowable charging current of the first battery is less than the rated current of the on-board charger, the on-board charger uses the maximum allowable charging current of the first battery as the AC charging current of the battery pack.

[0073] In other embodiments, optionally, step S160 specifically includes:

[0074] The on-board charger compares the maximum allowable charging current of the second battery with the rated current of the on-board charger to obtain a second comparison result.

[0075] The on-board charger determines the DC charging current of the battery pack according to the second comparison result.

[0076] Specifically, if the second comparison result is that the maximum allowable charging current of the second battery is greater than or equal to the rated current of the on-board charger, the on-board charger uses the rated current of the on-board charger as the DC charging current of the battery pack; if the second comparison result is that the maximum allowable charging current of the second battery is less than the rated current of the on-board charger, the on-board charger uses the maximum allowable charging current of the second battery as the DC charging current of the battery pack.

[0077] Optionally, before step S110, the method further includes:

[0078] Detect a first connection signal of the AC charging socket and a second connection signal of the DC charging socket, where the first connection signal is a signal when the AC charging socket is connected to an AC charging gun, and the second connection signal is a signal when the DC charging socket is connected to a DC charging gun.

[0079] Specifically, the onboard charger detects a first connection signal of the AC charging socket, and the battery management system BMS detects a second connection signal of the DC charging socket.

[0080] A charging mode of the battery pack is determined according to the first connection signal or the second connection signal.

[0081] Specifically, when the on-board charger detects the first connection signal of the AC charging socket, the charging mode of the battery pack is the first charging mode; when the battery management system BMS detects the second connection signal of the DC charging socket, the charging mode of the battery pack is the second charging mode.

[0082] Optionally, after step S130, the method further includes:

[0083] When the charging termination conditions are met, the on-board charger stops outputting AC charging current to the battery pack based on the stop charging signal sent by the battery management system.

[0084] Specifically, the BMS monitors the battery status, such as state of charge, voltage, temperature, internal resistance, etc., and the charging environment, such as grid voltage stability, in real time. When any termination condition is met, for example, the battery's state of charge reaches the set threshold, or the battery temperature is detected to exceed the safe range, the BMS enters the "termination of charging" logic. The BMS sends a "stop charging signal" to the on-board charger via the CAN bus or hard-wired connection. The signal contains a clear shutdown instruction. After receiving the signal, the on-board charger immediately cuts off the drive signal of the internal power device and stops converting the AC input into DC output, thereby cutting off the charging current to the battery pack. This process is the "active shutdown" mechanism of the charging system, which avoids battery overcharging leading to life degradation or safety hazards, or promptly interrupts charging under abnormal circumstances to ensure system safety.

[0085] Optionally, after step S170, the method further includes:

[0086] When the charging termination conditions are met, the on-board charger stops outputting DC charging current to the battery pack based on the stop charging signal sent by the battery management system.

[0087] This step has the same principle as the above step of "when the charging termination conditions are met, the on-board charger stops outputting AC charging current to the battery pack based on the stop charging signal sent by the battery management system", and will not be repeated here.

[0088] Continue to see Figure 2 An embodiment of the present invention further provides a power battery charging system, which includes: a battery pack 110, an on-board charger 120, a battery management system BMS130, an AC charging socket 140, and a DC charging socket 150; the AC charging socket 140 and the DC charging socket 150 are respectively electrically connected to the AC / DC module and DC / DC module inside the on-board charger 120, and the on-board charger 120 is electrically connected to the battery pack 110; the AC charging socket 140 and the DC charging socket 150 are also communicatively connected to the on-board charger 120, and the battery management system BMS130 is respectively communicatively connected to the DC charging socket 150 and the on-board charger 120.

[0089] In the first charging mode, the battery management system BMS130 is used to send a first battery charging voltage and a first battery maximum allowable charging current to the on-board charger. The first charging mode is a charging mode in which the AC charging socket is connected to the AC charging pile.

[0090] The on-board charger 120 is used to determine the AC charging current of the battery pack according to the maximum allowable charging current of the first battery and the rated current of the on-board charger when the AC voltage of the power grid is detected.

[0091] The on-board charger 120 is further configured to convert the AC voltage of the power grid into a first battery charging voltage, and charge the battery pack according to the first battery charging voltage and the AC charging current.

[0092] In the second charging mode, the battery management system BMS130 is used to obtain the rated operating voltage of the on-board charger and send the rated operating voltage to the DC charging pile connected to the DC charging socket, so that the DC charging pile is configured to output a DC charging voltage to the on-board charger in a constant voltage charging mode, and the DC charging voltage is consistent with the rated operating voltage of the on-board charger; the second charging mode is the charging mode in which the DC charging socket is connected to the DC charging pile.

[0093] The battery management system BMS130 is further configured to send the second battery charging voltage and the second battery maximum allowable charging current to the onboard charger.

[0094] The on-board charger 120 is configured to determine the DC charging current of the battery pack according to the maximum allowable charging current of the second battery and the rated current of the on-board charger.

[0095] The on-board charger 120 is further configured to convert the DC charging voltage into a second battery charging voltage, and charge the battery pack according to the second battery charging voltage and the DC charging current.

[0096] The power battery charging system provided in the embodiment of the present invention can execute the power battery charging method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0097] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0098] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A power battery charging method, characterized in that: The method is performed by a power battery charging system, the system including: a battery pack, an on-board charger, a battery management system, an AC charging socket, and a DC charging socket; the AC charging socket and the DC charging socket are electrically connected to the AC / DC module and DC / DC module inside the on-board charger, respectively, and the on-board charger is electrically connected to the battery pack; the AC charging socket and the DC charging socket are also communicatively connected to the on-board charger, and the battery management system is communicatively connected to the DC charging socket and the on-board charger, respectively; the method includes: In a first charging mode, the battery management system sends a first battery charging voltage and a first battery maximum allowable charging current to the onboard charger. The first charging mode is a charging mode in which the AC charging socket is connected to an AC charging pile. When the on-board charger detects the AC voltage of the power grid, determining the AC charging current of the battery pack according to the maximum allowable charging current of the first battery and the rated current of the on-board charger; The on-board charger converts the grid AC voltage into the first battery charging voltage, and charges the battery pack according to the first battery charging voltage and the AC charging current; In the second charging mode, the battery management system obtains the rated operating voltage of the on-board charger and sends the rated operating voltage to the DC charging pile connected to the DC charging socket, so that the DC charging pile is configured to output a DC charging voltage to the on-board charger in a constant voltage charging mode, and the DC charging voltage is consistent with the rated operating voltage of the on-board charger; the second charging mode is a charging mode in which the DC charging socket is connected to the DC charging pile; The battery management system sends a second battery charging voltage and a second battery maximum allowable charging current to the on-board charger; The on-board charger determines the DC charging current of the battery pack according to the maximum allowable charging current of the second battery and the rated current of the on-board charger; The on-board charger converts the DC charging voltage into the second battery charging voltage, and charges the battery pack according to the second battery charging voltage and the DC charging current.

2. The method according to claim 1, characterized in that When the on-board charger detects the AC voltage of the power grid, determining the AC charging current of the battery pack according to the maximum allowable charging current of the first battery and the rated current of the on-board charger includes: When the on-board charger detects an AC voltage from a power grid, comparing the maximum allowable charging current of the first battery with the rated current of the on-board charger to obtain a first comparison result; The on-board charger determines the AC charging current of the battery pack according to the first comparison result.

3. The method according to claim 2, characterized in that The on-board charger determining the AC charging current of the battery pack according to the first comparison result includes: If the first comparison result is that the maximum allowable charging current of the first battery is greater than or equal to the rated current of the on-board charger, the on-board charger uses the rated current of the on-board charger as the AC charging current of the battery pack; If the first comparison result is that the maximum allowable charging current of the first battery is less than the rated current of the on-board charger, the on-board charger uses the maximum allowable charging current of the first battery as the AC charging current of the battery pack.

4. The method according to claim 1, wherein The determining, by the on-board charger, the DC charging current of the battery pack according to the maximum allowable charging current of the second battery and the rated current of the on-board charger includes: comparing, at the on-board charger, the maximum allowable charging current of the second battery and the rated current of the on-board charger to obtain a second comparison result; The on-board charger determines a DC charging current of the battery pack according to the second comparison result.

5. The method according to claim 4, characterized in that The on-board charger determining the DC charging current of the battery pack according to the second comparison result includes: If the second comparison result is that the maximum allowable charging current of the second battery is greater than or equal to the rated current of the on-board charger, the on-board charger uses the rated current of the on-board charger as the DC charging current of the battery pack; If the second comparison result is that the maximum allowable charging current of the second battery is less than the rated current of the on-board charger, the on-board charger uses the maximum allowable charging current of the second battery as the DC charging current of the battery pack.

6. The method according to claim 1, characterized in that In the first charging mode, before the battery management system sends the first battery charging voltage and the first battery maximum allowable charging current to the onboard charger, the battery management system further includes: detecting a first connection signal of the AC charging socket and a second connection signal of the DC charging socket, wherein the first connection signal is a signal when the AC charging socket is connected to an AC charging plug, and the second connection signal is a signal when the DC charging socket is connected to a DC charging plug; A charging mode of the battery pack is determined according to the first connection signal or the second connection signal.

7. The method according to claim 6, characterized in that The determining of the charging mode of the battery pack according to the first connection signal or the second connection signal includes: When the first connection signal of the AC charging socket is detected, the charging mode of the battery pack is the first charging mode; When the second connection signal of the DC charging socket is detected, the charging mode of the battery pack is the second charging mode.

8. The method according to claim 1, characterized in that After the on-board charger converts the grid AC voltage into the first battery charging voltage and charges the battery pack according to the first battery charging voltage and the AC charging current, the method further includes: When a charging termination condition is met, the on-board charger stops outputting the AC charging current to the battery pack based on a charging stop signal sent by the battery management system.

9. The method according to claim 1, characterized in that After the on-board charger converts the DC charging voltage into the second battery charging voltage and charges the battery pack according to the second battery charging voltage and the DC charging current, the method further includes: When a charging termination condition is met, the on-board charger stops outputting a DC charging current to the battery pack based on a charging stop signal sent by the battery management system.

10. A power battery charging system, characterized in that: include: A battery pack, an onboard charger, a battery management system, an AC charging socket, and a DC charging socket; the AC charging socket and the DC charging socket are electrically connected to the AC / DC module and DC / DC module inside the onboard charger, respectively, and the onboard charger is electrically connected to the battery pack; the AC charging socket and the DC charging socket are also communicatively connected to the onboard charger, and the battery management system is communicatively connected to the DC charging socket and the onboard charger, respectively; In a first charging mode, the battery management system is used to send a first battery charging voltage and a first battery maximum allowable charging current to the on-board charger. The first charging mode is a charging mode in which the AC charging socket is connected to an AC charging pile. The on-board charger is used to determine the AC charging current of the battery pack according to the maximum allowable charging current of the first battery and the rated current of the on-board charger when the AC voltage of the power grid is detected; The on-board charger is further configured to convert the grid AC voltage into the first battery charging voltage, and charge the battery pack according to the first battery charging voltage and the AC charging current; In the second charging mode, the battery management system is used to obtain the rated operating voltage of the on-board charger and send the rated operating voltage to the DC charging pile connected to the DC charging socket, so that the DC charging pile is configured to output a DC charging voltage to the on-board charger in a constant voltage charging mode, and the DC charging voltage is consistent with the rated operating voltage of the on-board charger; the second charging mode is a charging mode in which the DC charging socket is connected to the DC charging pile; The battery management system is further configured to send a second battery charging voltage and a second battery maximum allowable charging current to the onboard charger; The on-board charger is used to determine the DC charging current of the battery pack according to the maximum allowable charging current of the second battery and the rated current of the on-board charger; The on-board charger is further configured to convert the DC charging voltage into the second battery charging voltage, and charge the battery pack according to the second battery charging voltage and the DC charging current.

Images