Charging method and power conversion device

Abstract

The present application discloses a charging method, comprising: a power conversion device acquiring state parameters of a power battery, the state parameters including the battery temperature; when the battery temperature is lower than a first preset threshold, the power conversion device sets the charging mode to a pulse charging mode; in the pulse charging mode, the power conversion device converts the charging power of a charging pile and then charges the power battery, wherein the pulse charging mode is a charging mode that outputs a pulsed voltage or a pulsed current. Through this technical solution, the power conversion device acquires the battery temperature of the power battery, and when the battery temperature is lower than the first preset threshold, the power conversion device converts the charging power output by the charging pile and outputs pulse electricity to charge the power battery, thereby preventing the charging pile from directly charging the power battery at low temperatures and affecting the performance of the power battery, thereby ensuring the performance of the power battery.

Description

Technical Field

[0001] The present application relates to the field of power batteries, and more specifically, to a charging method and a power conversion device. Background Art

[0002] With the development of the times, electric vehicles have huge market prospects due to their high environmental protection, low noise, low cost of use and other advantages. They can effectively promote energy conservation and emission reduction, which is beneficial to the development and progress of society.

[0003] For electric vehicles, power battery technology is a crucial factor in their development. Due to the electrochemical characteristics of power batteries, DC charging in low-temperature environments can significantly impact their performance, affecting the user experience.

[0004] Therefore, how to ensure the battery performance of power batteries is a technical problem to be solved. Summary of the Invention

[0005] The embodiments of the present application provide a charging method and a power conversion device, which can ensure the battery performance of a power battery.

[0006] In a first aspect, a charging method is provided, the method comprising: a power conversion device acquiring state parameters of a power battery, the state parameters including a battery temperature; when the battery temperature is lower than a first preset threshold value, the power conversion device sets the charging mode to a pulse charging mode; in the pulse charging mode, the power conversion device converts the charging power of the charging pile and then charges the power battery, the pulse charging mode being a charging mode that outputs a pulse voltage or a pulse current.

[0007] Through the technical solutions of the embodiments of the present application, the power conversion device obtains the battery temperature of the power battery. When the battery temperature is low, for example, below a first preset threshold, its charging mode is set to pulse charging mode. In this pulse charging mode, the power conversion device converts the charging power output by the charging pile and outputs pulse electricity to charge the power battery, preventing the charging pile from directly charging the power battery at low temperatures and affecting the performance of the power battery, thereby ensuring the performance of the power battery. In addition, through the technical solutions of the embodiments of the present application, there is no need to configure a thermal management system for the power battery. On the basis of reducing the overall cost of the power battery, it saves the heating time of the power battery at low temperatures and improves charging efficiency.

[0008] In one possible implementation, the method also includes: when the battery temperature is not lower than the first preset threshold, the power conversion device switches the charging mode from the pulse charging mode to the DC charging mode; in the DC charging mode, the power conversion device transmits the charging power of the charging pile to the power battery to charge the power battery, wherein the DC charging mode is a charging mode that outputs a constant voltage or a constant current.

[0009] Through the technical solution of the embodiment of the present application, the power conversion device continuously obtains the battery temperature of the power battery. When the battery temperature is high, for example, not lower than the first preset threshold value, its charging mode is switched from the pulse charging mode to the DC charging mode, and then the power conversion device directly transmits the charging power of the charging pile to the power battery to charge the power battery, thereby improving the charging efficiency of the power battery under non-low temperature conditions. Therefore, through the technical solution of the embodiment of the present application, the power conversion device can flexibly set its charging mode according to the battery temperature of the power battery, thereby improving the charging efficiency of the entire charging process while ensuring the performance of the power battery.

[0010] In one possible implementation, the state parameter also includes: battery voltage; when the battery temperature is lower than a first preset threshold, the power conversion device sets the charging mode to a pulse charging mode, including: when the battery temperature is lower than the first preset threshold and the battery voltage is lower than a second preset threshold, the power conversion device sets the charging mode to the pulse charging mode.

[0011] In the technical solution of the embodiment of the present application, in addition to obtaining the battery temperature of the power battery, the power conversion device also obtains the battery voltage of the power battery, and sets its charging mode to the pulse charging mode based on the comprehensive information of the battery temperature and battery voltage. At low temperatures, it can further determine whether the power battery is in a low-voltage waiting-to-charge state, which can further ensure charging safety.

[0012] In one possible implementation, the state parameter also includes: battery voltage. When the battery temperature is not lower than the first preset threshold, the power conversion device switches the charging mode from the pulse charging mode to the DC charging mode, including: when the battery temperature is not lower than the first preset threshold or the battery voltage is not lower than the second preset threshold, the power conversion device switches the charging mode from the pulse charging mode to the DC charging mode.

[0013] Through the technical solution of the embodiment of the present application, the power conversion device continuously obtains the battery temperature and battery voltage of the power battery, and switches its charging mode from the pulse charging mode to the DC charging mode based on the information of the battery temperature and battery voltage. When the battery is not in a low temperature or low voltage state, the rechargeable battery is directly charged with DC power, which can further improve the charging efficiency.

[0014] In one possible implementation, the state parameter also includes the battery state of charge; the power conversion device sets the charging mode to a pulse charging mode, including: the power conversion device sends first DC charging information to the charging pile, and the first DC charging information is determined by the power conversion device based on the pulse charging information, wherein the pulse charging information includes at least one of the following information: pulse current information, pulse voltage information, pulse direction information, pulse frequency information and pulse time information, and the pulse charging information is determined by the power conversion device based on the battery temperature and the battery state of charge; in the pulse charging mode, the power conversion device converts the charging power of the charging pile and then charges the power battery, including: the power conversion device outputs a pulse current to the power battery, wherein the pulse current is generated by converting the DC current based on the pulse charging information, and the DC current is the DC current output by the charging pile to the power conversion device based on the first DC charging information.

[0015] Through the technical solution of the embodiment of the present application, the power conversion equipment can determine the corresponding pulse charging information based on the state parameters of the power battery it obtains, and convert different pulse currents according to the pulse charging information to adapt to the different charging requirements of the power battery in different situations, with high flexibility and adaptability.

[0016] In one possible implementation, before the power conversion device sets the charging mode to the pulse charging mode, the method further includes: the power conversion device sends a charging prohibition message to the charging pile, and the charging prohibition message is used to instruct the charging pile to stop outputting DC current to the power conversion device.

[0017] In a possible implementation, after the power conversion device sends a charging prohibition message to the charging pile, the method further includes: the power conversion device performs pre-charging.

[0018] Through the technical solution of the embodiment of the present application, after the power conversion device sends a charging prohibition message to the charging pile, the capacitor in the power conversion device is pre-charged. In this way, during the subsequent charging process of the power battery, the capacitor will no longer induce a large pulse current, thereby ensuring the normal and safe charging process.

[0019] In a possible implementation, the power conversion device performs pre-charging, including: the power conversion device obtains a voltage difference between an input terminal and an output terminal thereof; if the voltage difference is less than a third preset threshold, the power conversion device performs pre-charging.

[0020] Through the technical solution of the embodiment of the present application, in order to protect the relays in the power conversion device and ensure the performance of the power conversion device, before controlling the switch of the relay to pre-charge the power conversion device, the power conversion device can also obtain the voltage difference between its input and output ends, and determine whether the voltage difference is less than a third preset threshold value. If the voltage difference is less than the third preset threshold value, the power conversion device is pre-charged.

[0021] In one possible implementation, the power conversion device switches the charging mode from the pulse charging mode to the DC charging mode, including: the power conversion device stops outputting pulse current to the power battery; the power conversion device obtains second DC charging information of the power battery and sends the second DC charging information to the charging pile; the power conversion device transmits the charging power of the charging pile to the power battery to charge the power battery, including: the power conversion device outputs the DC current output by the charging pile according to the second DC charging information to the power battery to charge the power battery.

[0022] In one possible implementation, before the power conversion device stops outputting pulse current to the power battery, the method further includes: the power conversion device sends a charging prohibition message to the charging pile, where the charging prohibition message is used to instruct the charging pile to stop outputting DC current to the power conversion device.

[0023] In one possible implementation, the power conversion device outputs the DC current output by the charging pile according to the second DC charging information to the power battery to charge the power battery, including: the power conversion device obtains the voltage difference between its input end and output end; if the voltage difference is less than a fourth preset threshold, the power conversion device outputs the DC current output by the charging pile according to the second DC charging information to the power battery to charge the power battery.

[0024] Through the technical solution of the embodiment of the present application, in order to protect the relay in the power conversion device and ensure the performance of the power conversion device, before controlling the switch of the relay to output the DC current output by the charging pile to the power battery, the power conversion device can also obtain the voltage difference between its input and output ends, and determine whether the voltage difference is less than a fourth preset threshold value. If the voltage difference is less than the fourth preset threshold value, the power conversion device outputs the DC current output by the charging pile to the power battery to charge the power battery.

[0025] In a possible implementation, the power conversion device acquires the state parameter of the power battery, including: the power conversion device receives the state parameter of the power battery sent by a battery management system of the power battery.

[0026] In a second aspect, a power conversion device is provided, including: a control unit and a power unit; the control unit is used to obtain state parameters of the power battery, the state parameters including the battery temperature of the power battery; when the battery temperature is lower than a first preset threshold value, the control unit is used to set the charging mode of the power unit to a pulse charging mode, in which the power unit converts the charging power of the charging pile and then charges the power battery, and the pulse charging mode is a charging mode using a pulse voltage or a pulse current.

[0027] In one possible implementation, when the battery temperature is not lower than a first preset threshold, the control unit is further used to: switch the charging mode of the power unit from the pulse charging mode to the DC charging mode, in which the power unit is used to transmit the charging power of the charging pile to the power battery to charge the power battery, wherein the DC charging mode is a charging mode using a constant voltage or a constant current.

[0028] In a possible implementation, the state parameter also includes: battery voltage. When the battery temperature is lower than the first preset threshold and the battery voltage is lower than the second preset threshold, the control unit is configured to set the charging mode of the power unit to the pulse charging mode.

[0029] In one possible implementation, the state parameter also includes: battery voltage. When the battery temperature is not lower than the first preset threshold or the battery voltage is not lower than the second preset threshold, the control unit is used to switch the charging mode of the power unit from the pulse charging mode to the DC charging mode.

[0030] In one possible implementation, the status parameter also includes a battery state of charge; the control unit is used to determine pulse charging information based on the battery temperature and the battery state of charge, and send the pulse charging information to the power unit, where the pulse charging information includes at least one of the following information: pulse current, pulse voltage, pulse direction, pulse frequency, and pulse time; the power unit is used to determine first DC charging information corresponding to the pulse charging information based on the pulse charging information, and send the first DC charging information to the control unit; the control unit is used to send the first DC charging information to the charging pile, and control the power unit to output a pulse current to the power battery, wherein the pulse current is generated by converting the DC current based on the pulse charging information, and the DC current is the DC current output by the charging pile to the power unit based on the first DC charging information.

[0031] In one possible implementation, before the control unit is used to set the charging mode of the power unit to the pulse charging mode, the control unit is also used to: send a charging prohibition message to the charging pile, wherein the charging prohibition message is used to instruct the charging pile to stop outputting direct current to the power unit.

[0032] In a possible implementation, after the control unit is used to send a charging prohibition message to the charging pile, the control unit is further used to send a pre-charging instruction to the power unit; and the power unit is used to perform pre-charging according to the pre-charging instruction.

[0033] In one possible implementation, the control unit is used to obtain a voltage difference between an input end and an output end of the power unit; if the voltage difference is less than a third preset threshold, the control unit is used to send a pre-charge instruction to the power unit.

[0034] In one possible implementation, the control unit is also used to obtain second DC charging information of the power battery; the control unit is used to control the power unit to stop outputting pulse current; and the control unit is used to control the power unit to output the DC current output by the charging pile according to the second DC charging information to the power battery.

[0035] In one possible implementation, before the control unit is used to control the power unit to stop outputting pulse current, the control unit is also used to: send a charging prohibition message to the charging pile, and the charging prohibition message is used to instruct the charging pile to stop outputting DC current to the power unit.

[0036] In one possible implementation, the control unit is used to obtain the voltage difference between the input and output ends of the power unit; if the voltage difference is less than a fourth preset threshold, the control unit is used to control the power unit to output the DC current output by the charging pile according to the second DC charging information to the power battery.

[0037] In a possible implementation, the control unit is configured to receive a state parameter of the power battery sent by a battery management system of the power battery.

[0038] In a third aspect, a power conversion device is provided, comprising a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call the computer program to execute the method in the above-mentioned first aspect and any possible implementation of the first aspect.

[0039] In a fourth aspect, a computer-readable storage medium is provided for storing a computer program for executing the method according to the first aspect and any possible implementation of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0041] Figure 1 is a schematic diagram of a charging system disclosed in an embodiment of the present application;

[0042] Figure 2 is a schematic diagram of the application architecture of the charging system disclosed in one embodiment of the present application;

[0043] Figure 3 is a schematic flow chart of a charging method disclosed in one embodiment of the present application;

[0044] Figure 4 is a schematic flow chart of a charging method disclosed in another embodiment of the present application;

[0045] Figure 5 is a schematic flow chart of a charging method disclosed in another embodiment of the present application;

[0046] Figure 6 is a schematic flow chart of a charging method disclosed in another embodiment of the present application;

[0047] Figure 7 is a schematic interactive flow chart of a charging method disclosed in another embodiment of the present application;

[0048] Figure 8 is a schematic interactive flow chart of a charging method disclosed in another embodiment of the present application;

[0049] Figure 9 is a schematic interactive flow chart of a charging method disclosed in another embodiment of the present application;

[0050] Figure 10 is a schematic interactive flow chart of a charging method disclosed in another embodiment of the present application;

[0051] Figure 11 is a schematic flow chart of a charging method disclosed in another embodiment of the present application;

[0052] Figure 12 is a schematic interactive flow chart of a charging method disclosed in another embodiment of the present application;

[0053] Figure 13 is a schematic interactive flow chart of a charging method disclosed in another embodiment of the present application;

[0054] Figure 14 is a schematic interactive flow chart of a charging method disclosed in another embodiment of the present application;

[0055] Figure 15 is a schematic interactive flow chart of a charging method disclosed in another embodiment of the present application;

[0056] Figure 16 is a schematic block diagram of a power conversion device disclosed in an embodiment of the present application;

[0057] Figure 17 is a schematic block diagram of a power conversion device disclosed in another embodiment of the present application;

[0058] Figure 18 It is a schematic block diagram of a power conversion device disclosed in another embodiment of the present application. DETAILED DESCRIPTION

[0059] The following detailed description of the embodiments of the present application is provided in conjunction with the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present application, but are not intended to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0060] In the description of this application, it should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0061] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0062] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0063] In the field of new energy, power batteries are the main power source for electrical devices such as vehicles, ships or spacecraft, and their importance is self-evident. Among them, the temperature of power batteries has a great impact on their performance, lifespan and safety. Currently, most power batteries on the market are rechargeable batteries, the most common of which are lithium-ion batteries or lithium-ion polymer batteries. At low temperatures, lithium-ion batteries will experience increased internal resistance and reduced capacity. In extreme cases, it will cause the electrolyte to freeze and the battery to be unable to discharge. The low-temperature performance of the battery system is greatly affected, resulting in a decline in the power output performance and a reduction in the driving range of electric vehicles. Furthermore, DC charging of lithium-ion batteries at low temperatures will cause lithium plating. Lithium plating not only reduces the performance of lithium batteries and significantly shortens the cycle life, but also limits the fast charging capacity of the battery and may cause catastrophic consequences such as combustion and explosion.

[0064] To address the issue of charging electric vehicles in low-temperature environments, most electric vehicle power batteries currently on the market are equipped with thermal management systems. When the power battery temperature is too low, the thermal management system converts some of the electrical energy into heat, thereby heating the entire battery pack. This preheating method brings the power battery to a more suitable temperature before charging. However, this preheating method raises the power battery temperature before charging, resulting in limited room for improvement in heating efficiency and inability to reduce heating time, making it unable to fundamentally address the issue of long charging times in low-temperature environments. Furthermore, incorporating a thermal management system into the power battery increases both weight and cost.

[0065] In view of this, compared with the existing technology, this application proposes a new charging system and charging method, which does not require the use of a thermal management system to preheat the power battery and can also solve the above-mentioned problem of charging electric vehicles in low temperature environments.

[0066] Figure 1 A charging system applicable to the embodiment of the present application is shown. The charging system can be applied to various types of electrical devices, including but not limited to electric vehicles, etc.

[0067] Figure 1A schematic diagram of a charging system 10 in the present application is shown.

[0068] like Figure 1 As shown, the charging system 10 may include: a power conversion device 110 , a charging pile 120 and an electric vehicle 130 .

[0069] Specifically, the charging pile 120 is a device for replenishing electric energy for electric vehicles 130 (including pure electric vehicles and plug-in hybrid electric vehicles), which can be divided into two categories: AC charging piles and DC charging piles. Among them, the DC charging pile directly charges the power battery of the electric vehicle by outputting adjustable direct current. The output voltage and current have a large adjustment range and can meet the needs of fast charging. The AC charging pile only provides power output and has no charging function. The subsequent rectification and DC-DC (DC-DC) conversion are all completed by the on-board charger. The charging pile is used to act as a power controller. In the following application embodiments, the charging pile is a DC charging pile as an example to illustrate the charging method of the present application. The relevant charging method of the on-board charger can refer to the relevant description of the following embodiments.

[0070] Specifically, the electric vehicle 130 may include a battery system, which may be provided with at least one battery pack to provide energy and power for the electric vehicle. The at least one battery pack may be collectively referred to as a power battery. In terms of battery type, the power battery may be a lithium-ion battery, a lithium metal battery, a lead-acid battery, a nickel-cathode battery, a nickel-metal hydride battery, a lithium-sulfur battery, a lithium-air battery, or a sodium-ion battery, etc., which is not specifically limited in the embodiments of the present application. In terms of battery size, the power battery in the embodiments of the present application may be a battery cell / battery monomer, or a battery module or a battery pack, which is not specifically limited in the embodiments of the present application.

[0071] In addition, in order to intelligently manage and maintain the power battery, prevent overcharging and over-discharging, and extend the battery life, the battery system is generally equipped with a battery management system (BMS) to monitor the status of the power battery. Optionally, the BMS can be integrated with the power battery and installed in the same device / apparatus, or the BMS can be installed as an independent device / apparatus outside the power battery.

[0072] Compared with the existing technology, the charging system 10 has a new power conversion device 110. Specifically, the power conversion device 110 can be electrically connected to the charging pile 120 and to the battery system of the electric vehicle 130. The power conversion device 110 can serve as a power transfer device between the charging pile 120 and the battery system of the electric vehicle 130. Specifically, the power conversion device 110 can serve as a power transfer device between the charging pile 120 and the power battery of the electric vehicle 130.

[0073] Specifically, in the present application, the power conversion device 110 is used to receive first electrical energy of a first power type transmitted by the charging station 120, convert the first electrical energy into second electrical energy of a second power type different from the first power type, and then transmit the second electrical energy to the power battery of the electric vehicle 130 to achieve power conversion. As an example, the first electrical energy of the first power type transmitted by the charging station 120 is direct current, which can be constant voltage direct current or constant current direct current. The power conversion device 110 can convert the direct current into second electrical energy of other power types, such as voltage changes, current changes, power state changes, current, voltage, and power timing changes, and then transmit it to the power battery of the electric vehicle 130 to charge the power battery.

[0074] Alternatively, as Figure 1 As shown, the power conversion device 110 is an independent power transfer device, which is installed outside the charging pile 120 and the electric vehicle 130. As an optional electrical connection method, the charging pile 120 is provided with a first charging gun head, and the power conversion device 110 is provided with a first charging socket corresponding to the first charging gun head to receive the power transmitted from the charging pile 120. In addition, the power conversion device 110 is also provided with a second charging gun head, which is used to electrically connect to the second charging socket on the electric vehicle 110 to enable the power conversion device 110 to transmit power to the electric vehicle.

[0075] To adapt to the electrical connection between the existing charging pile 120 and the battery system of the electric vehicle 130, the specific type and structure of the second charging gun head on the power conversion device 110 can optionally be the same as the specific type and structure of the first charging gun head on the charging pile 120. Correspondingly, the specific type and structure of the first charging socket on the power conversion device 110 can be the same as the specific type and structure of the second charging socket on the electric vehicle. Of course, the second charging gun head and the first charging socket on the power conversion device 110 can also be different from the first charging gun head on the charging pile 120 and the second charging socket on the electric vehicle. This embodiment of the present application does not specifically limit this. The purpose is to achieve electrical connection between the charging gun head and its corresponding charging socket.

[0076] Optionally, in addition to being designed as an independent power transfer device, the power conversion device 110 can also be integrated into the charging pile 120 or integrated into the electric vehicle 130, or some functional modules in the power conversion device 110 are set in the charging pile 120, and other functional modules are set in the electric vehicle 130. The embodiment of the present application does not specifically limit the specific setting method of the power conversion device 110, and is intended to be electrically connected between the charging pile 120 and the battery system of the electric vehicle 130 to realize the power conversion function.

[0077] Figure 2 Schematic diagram of an application architecture of the charging system 10 according to an embodiment of the present application.

[0078] like Figure 2 As shown, the battery system may be the battery system in the electric vehicle 130 in the above-mentioned charging system 10 , and the battery system includes a power battery 131 and a battery management system BMS 132 .

[0079] Optionally, the power conversion device 110 may include a power unit 111 and a control unit 112. The power unit 111 is used to convert the power type output by the charging pile 120 into the power type required by the power battery 131. As an example, the power unit 111 may include a power conversion module. The power conversion module may include a pulse generating circuit for generating pulse electricity to provide to the power battery 131. In addition, the power conversion module may also include other functional circuits such as a drive circuit, a communication circuit, and a processing circuit. The control unit 112 may include a controller and / or a processor, which is responsible for detecting the status of the charging pile 120 and the BMS 130 during the charging process, and controlling the operation of the power unit 111 and other electrical components in the power conversion device.

[0080] Specifically, the power unit 111 is connected to the charging pile 120 and the power battery 131 through the high-voltage line 150, so as to convert the charging power outputted by the charging pile 120 through the high-voltage line 150 and output it to the power battery 131 to charge the power battery 131. As an example, Figure 2 As shown, the power conversion module in the power unit 111 is connected to the positive output port (for example: DC positive output port DC+) and the negative output port (for example: DC negative output port DC-) of the charging pile through the high-voltage line 150, and is connected to the positive output port and the negative output port of the power battery.

[0081] Optionally, the power unit 111 includes at least one relay in addition to the power conversion module, for example Figure 2As shown, it includes a first relay K1, a second relay K2, and a third relay K3. The power conversion module is connected to the charging pile 120 and the power battery 131 through the second relay K2 and the third relay K3, respectively. Whether the power conversion module is connected to the charging pile 120 and the power battery 131 can be controlled by controlling the second relay K2 and the third relay K3.

[0082] In addition, the charging pile 120 and the power battery 131 are connected to each other through the first relay K1. In other words, if the second relay K2 and the third relay K3 are both disconnected and the first relay K1 is closed, the charging power output by the charging pile 120 can be directly transmitted to the power battery 131 without the need for conversion by the power conversion module.

[0083] It should be noted that Figure 2 The first relay K1, the second relay K2 and the third relay K3 are only schematically illustrated circuit structures, which can also be replaced by other functional circuits to achieve selective connection of the power conversion module between the charging pile 120 and the power battery 131.

[0084] It can be understood that the first relay K1 , the second relay K2 and the third relay K3 can be controlled by the control unit 112 in the power conversion device 110 .

[0085] It can also be understood that the power unit 111 may not include the first relay K1, the second relay K2 and the third relay K3. The operating status of the power conversion module can be directly controlled by software, and the power conversion module can be selectively connected between the charging pile 120 and the power battery 131, so that the power conversion device 110 is in different charging modes.

[0086] See further Figure 2 The charging pile 120 and the BMS 132 can also be connected to the power conversion device 110 via a communication line 140, respectively, to enable information exchange between the charging pile 120, the BMS 132, and the power conversion device 110. Specifically, the control unit 112 is connected to the charging pile 120 and the BMS 130 via the communication line 140, respectively, to exchange information with the charging pile 120 and the BMS 130, respectively. In addition, the control unit 112 is also connected to the power unit 111 via the communication line 140 to exchange information with the power unit 111 and control the power unit 111 to perform power conversion.

[0087] As an example, the communication line 140 includes, but is not limited to, a controller area network (CAN) communication bus or a daisy chain communication bus. Optionally, the charging station 120, the BMS 132, and the power conversion device 110 can communicate based on the relevant protocols of the communication physical layer, data link layer, and application layer of the CAN communication protocol or the daisy chain communication protocol.

[0088] Specifically, in conventional charging systems on the market, the charging pile 120 and the BMS 132 directly exchange information through a communication protocol. In an embodiment of the present application, the power conversion device 110 can receive and send messages and messages between the charging pile 120 and the BMS 132, and realize power conversion between the charging pile 120 and the BMS 132 while being compatible with the current communication protocol of the charging pile 120 and the BMS 132.

[0089] Figure 3 A schematic flow chart of a charging method 200 proposed in an embodiment of the present application is shown. The method 200 is applied to a power conversion device. For example, the power conversion device can be the above Figure 1 and Figure 2 The power conversion device 110 in.

[0090] like Figure 3 As shown, the charging method 200 may include the following steps.

[0091] Step 210: The power conversion device obtains state parameters of the power battery, which include the battery temperature.

[0092] Optionally, in this step, the power battery can be Figure 2 The power battery 131 shown in FIG. 1 generally includes at least one battery pack, each of which may include multiple battery cells connected in series and parallel. The battery temperature of the power battery includes, but is not limited to, the temperature of each battery cell. In related art, a battery cell may also be referred to as a battery cell.

[0093] Optionally, in some embodiments, the BMS of the power battery, e.g. Figure 2The BMS 132 shown in the figure is used to detect the state parameters of the power battery, such as the battery temperature of the power battery, and transmit them to the power conversion device so that the power conversion device obtains the state parameters of the power battery. As an example, communication between the BMS and the power conversion device can be based on CAN. In this example, the battery temperature of the power battery can be the lowest power battery temperature in the power battery status information message (battery state message, BSM) sent by the BMS. In other examples, the BMS and the power conversion device can also communicate based on other communication protocols, which is not specifically limited in the embodiments of the present application.

[0094] Of course, in other embodiments, the power conversion device may also obtain the status parameters of the power battery through other means. As an example, other control units other than the BMS in the power vehicle are used to obtain the status parameters of the power battery, which are then transmitted to the power conversion device by the control unit; or, as another example, the BMS or other control unit in the power vehicle stores the status parameters of the power battery in a storage unit or the cloud, and the power conversion device obtains the battery status parameters from the storage unit or the cloud. The embodiments of the present application do not limit the specific method for the power conversion device to obtain the status parameters of the power battery.

[0095] Step 220: When the battery temperature is lower than a first preset threshold, the power conversion device sets the charging mode to a pulse charging mode.

[0096] Specifically, in this step, the pulse charging mode is a charging mode using a pulse voltage or a pulse current. In other words, in the pulse charging mode, the power conversion device can generate a pulse voltage or a pulse current.

[0097] Optionally, the operating status of each functional module in the power conversion device can be controlled by controlling the software program and / or hardware circuit in the power conversion device, so that the power conversion device can convert the direct current received from the charging pile into pulse power.

[0098] As an example, in Figure 2 In the power conversion device 110 shown, the second relay K2 and the third relay K3 can be controlled to be closed to connect the power conversion module between the charging pile 120 and the power battery 131, so that the power conversion device 110 can convert the direct current received from the charging pile 120 into pulse power.

[0099] Optionally, the first preset threshold value may be any preset value, intended to indicate that the power battery is in a low-temperature state. The first preset threshold value may be set based on factors such as the location of the power battery, its battery type, property parameters, and the system architecture in which the power battery is located. The present application does not limit its specific value. As an example, the first preset threshold value may be any value lower than 10 degrees Celsius (°C), for example, the first preset threshold value may be 5°C.

[0100] Step 230: In the pulse charging mode, the power conversion device converts the charging power of the charging pile to charge the power battery.

[0101] Specifically, in this step, the power conversion device is used to convert the charging power of the charging pile and output the converted charging power to the power battery to charge the power battery. In the pulse charging mode, the charging power converted by the power conversion device is a pulse charging voltage or a pulse charging current.

[0102] In summary, through the technical solutions of the embodiments of the present application, the power conversion device obtains the battery temperature of the power battery. When the battery temperature is low, for example, below a first preset threshold, its charging mode is set to pulse charging mode. In this pulse charging mode, the power conversion device converts the charging power output by the charging pile and outputs pulse electricity to charge the power battery, preventing direct charging of the power battery at low temperatures from affecting the performance of the power battery, thereby ensuring the performance of the power battery. In addition, through the technical solutions of the embodiments of the present application, there is no need to configure a thermal management system for the power battery. On the basis of reducing the overall cost of the power battery, it saves the heating time of the power battery at low temperatures and improves charging efficiency.

[0103] Figure 4 A schematic flow chart of another charging method 300 provided in an embodiment of the present application is shown.

[0104] like Figure 4 As shown, the charging method 300 may include the following steps.

[0105] Step 310: The power conversion device obtains battery status parameters of the power battery, which include battery temperature and battery voltage.

[0106] Step 320: When the battery temperature is lower than a first preset threshold and the battery voltage is lower than a second preset threshold, the power conversion device sets the charging mode to a pulse charging mode.

[0107] Step 330: In the pulse charging mode, the power conversion device converts the charging power of the charging pile to charge the power battery.

[0108] In the embodiment of the present application, compared with the above step 210, in step 310, the power conversion device not only obtains the battery temperature of the power battery, but also obtains the battery voltage of the power battery.

[0109] Specifically, during the charging and discharging process of a power battery, in addition to the significant impact of battery temperature, simultaneously detecting its voltage can better reflect the current charging and discharging status of the power battery, preventing overcharging or overdischarging, which could cause permanent damage to the power battery. Therefore, in an embodiment of the present application, the power conversion device not only obtains the battery temperature of the power battery, but also obtains the battery voltage of the power battery. This information is integrated into the subsequent charging mode setting phase to improve charging safety. Specifically, the battery voltage of the power battery includes, but is not limited to, the voltage of each battery cell in the power battery and / or the total voltage of the entire power battery.

[0110] Similar to the power conversion device obtaining the battery temperature of the power battery in step 210 above, in some embodiments, the power battery's BMS is used to detect the battery voltage of the power battery and transmit it to the power conversion device, so that the power conversion device obtains the battery voltage of the power battery. In this embodiment, the battery voltage of the power battery can be transmitted to the power conversion device via a battery charge state (BCS) message.

[0111] In step 320, when the battery temperature is below a first preset threshold and the battery voltage is below a second preset threshold, the power conversion device sets the charging mode to pulse charging mode. Optionally, the second preset threshold can be any preset value, intended to indicate that the power battery is in a low-voltage state ready for charging. The second preset threshold may be set to different values ​​depending on the type and structure of the power battery, and this embodiment of the present application does not specifically limit this.

[0112] Specifically, the relevant technical solutions of step 330 in the embodiment of the present application can be found in the relevant description of step 230 above, which will not be repeated here.

[0113] In the technical solution of the embodiment of the present application, in addition to obtaining the battery temperature of the power battery, the power conversion device also obtains the battery voltage of the power battery, and sets its charging mode to the pulse charging mode based on the comprehensive information of the battery temperature and battery voltage. At low temperatures, it can further determine whether the power battery is in a low-voltage waiting-to-charge state, which can further ensure charging safety.

[0114] It should be noted that in the embodiments of the present application, in addition to obtaining the battery temperature and battery voltage of the power battery, the power conversion device can also obtain other state parameters of the power battery and further set its charging mode to pulse charging mode based on these other state parameters. Specifically, the other state parameters of the power battery include, but are not limited to, battery current, battery state of charge (SOC), estimated remaining charging time, and other related parameters. SOC can be regarded as a thermodynamic quantity that can be used to evaluate the potential electrical energy of the battery.

[0115] In the above Figure 3 and Figure 4 In the described charging method, the power conversion device sets its charging mode to pulse charging mode and converts the output power of the charging pile before outputting it to the power battery. Furthermore, the power conversion device can also switch its charging mode to DC charging mode and transmit the charging power from the charging pile directly to the power battery.

[0116] Figure 5 A schematic flow chart of another charging method 200 provided in an embodiment of the present application is shown.

[0117] like Figure 5 As shown, the charging method 200 may further include the following steps.

[0118] Step 240: When the battery temperature is not lower than a first preset threshold, the power conversion device switches the charging mode from the pulse charging mode to the DC charging mode.

[0119] Step 250: In the DC charging mode, the power conversion device transmits the charging power of the charging pile to the power battery.

[0120] Specifically, in the embodiment of the present application, the above steps 240 and 250 occur in Figure 3 After step 230 in , if the battery temperature obtained by the power conversion device in the current state is not lower than the first preset threshold value, it means that the current power battery is in a non-low temperature state, and the charging mode of the power conversion device can be switched from the pulse charging mode to the DC charging mode. In the DC charging mode, the power conversion device directly transmits the charging power output by the charging pile to the power battery to charge the power battery. The DC charging mode is a charging mode that outputs a constant voltage or a constant current. In other words, the charging power of the charging pile is a constant voltage or a constant current.

[0121] As an example, the operating status of each functional module in the power conversion device can be controlled by controlling the software program and / or hardware circuit in the power conversion device, so that the power conversion device can directly output the DC power it receives from the charging pile to the power battery.

[0122] For example, in Figure 2 In the power conversion device 110 shown, by controlling the second relay K2 and the third relay K3 to be disconnected and controlling the first relay K1 to be closed, a direct electrical connection is achieved between the charging pile 120 and the power battery 131, so that the power conversion device 110 can directly output the DC power it receives from the charging pile 120 to the power battery 131.

[0123] Furthermore, in Figure 2 In the power conversion device 110 shown, the power conversion module can be controlled to stop running to further enhance the reliability and flexibility during the charging mode switching process.

[0124] Through the technical solution of the embodiment of the present application, the power conversion device continuously obtains the battery temperature of the power battery. When the battery temperature is high, for example, not lower than the first preset threshold value, its charging mode is switched from the pulse charging mode to the DC charging mode, and then the power conversion device directly transmits the charging power of the charging pile to the power battery to charge the power battery, thereby improving the charging efficiency of the power battery under non-low temperature conditions. Therefore, through the technical solution of the embodiment of the present application, the power conversion device can flexibly set its charging mode according to the battery temperature of the power battery, thereby improving the charging efficiency of the entire charging process while ensuring the performance of the power battery.

[0125] Similarly, Figure 6 A schematic flow chart of another charging method 300 provided in an embodiment of the present application is shown.

[0126] like Figure 6 As shown, the charging method 300 may further include the following steps.

[0127] Step 340: When the battery temperature is not lower than a first preset threshold, or the battery voltage is not lower than a second preset threshold, the power conversion device switches the charging mode from the pulse charging mode to the DC charging mode.

[0128] Step 350: In the DC charging mode, the power conversion device transmits the charging power of the charging pile to the power battery.

[0129] In the embodiment of the present application, steps 340 and 350 occur in the above Figure 4After step 330 in , if the battery temperature obtained by the power conversion device in the current state is not lower than the first preset threshold value, it means that the current power battery is in a non-low temperature state, or if the battery voltage obtained by the power conversion device in the current state is not lower than the second preset threshold value, it means that the current power battery is not in a state to be charged, or is in a state to be charged with a higher voltage. The charging mode of the power conversion device can be switched from the pulse charging mode to the DC charging mode. In the DC charging mode, the charging pile charges the power battery through the power conversion device.

[0130] Through the technical solution of the embodiment of the present application, the power conversion device continuously obtains the battery temperature and battery voltage of the power battery, and switches its charging mode from the pulse charging mode to the DC charging mode based on the information of the battery temperature and battery voltage. When the battery is not in a low temperature or low voltage state, the rechargeable battery is directly charged with DC power, which can further improve the charging efficiency.

[0131] It should be noted that in the above-mentioned application embodiments, when the power conversion device is in pulse charging mode, if it is detected that the battery temperature is not lower than a first preset threshold, or the battery voltage is not lower than a second preset threshold, the power conversion device needs to switch its charging mode from pulse charging mode to DC charging mode. In other application embodiments, in the initial state of the power conversion device, that is, when the power conversion device is not set to a charging mode, if the battery temperature of the power battery obtained by the power conversion device is not lower than the first preset threshold, or the battery voltage is not lower than the second preset threshold, the power conversion device can directly set its charging mode to DC charging mode.

[0132] In addition, it should be noted that in the above steps 220 and 320, in some cases, if the power conversion device is in the initial state, when the battery temperature is lower than the first preset threshold, or when the battery temperature is lower than the first preset threshold and the battery voltage is lower than the second preset threshold, the power conversion device directly sets its charging mode to the pulse charging mode. In other cases, if the power conversion device is in the DC charging mode, when the battery temperature is lower than the first preset threshold, or when the battery temperature is lower than the first preset threshold and the battery voltage is lower than the second preset threshold, the power conversion device may switch the charging mode from the DC charging mode to the pulse charging mode.

[0133] In summary, the technical solutions of the embodiments of this application enable the power conversion device to adjust its charging mode at any time according to the state parameters of the power battery throughout the charging process. Specifically, pulse charging of the power battery can be performed at low temperatures, while DC charging can be performed at warm temperatures, flexibly adapting to different charging environments and improving charging efficiency.

[0134] Figure 7FIG. 4 is a schematic flow chart showing a charging method 400 according to another embodiment of the present application.

[0135] like Figure 7 As shown, the charging method 400 may include the following steps.

[0136] Step 410: The battery management system BMS sends battery status parameters of the power battery to the power conversion device. The status parameters include battery temperature and battery state of charge.

[0137] Specifically, in this step, the battery management system (BMS) not only sends the power battery's temperature to the power conversion device, but also sends the power battery's state of charge (SOC). This SOC can more accurately reflect the remaining power in the power battery. Optionally, the battery management system (BMS) can also send other parameters such as the power battery's voltage to the power conversion device.

[0138] Optionally, in an embodiment of the present application, the battery temperature of the power battery can be sent to the power conversion device through a power battery status information message (BSM), and the battery state of charge SOC, battery voltage and other parameters of the power battery can be sent to the power conversion device through a battery charging status message (BCS).

[0139] Step 421: When the battery temperature is lower than a first preset threshold, the power conversion device determines pulse charging information according to the state parameter.

[0140] Specifically, in this step, when the battery temperature is lower than the first preset threshold, the pulse charging information determined by the power conversion device based on the battery temperature and SOC can adapt to both the current temperature and SOC of the power battery.

[0141] Alternatively, in another embodiment of this step, when the battery temperature is lower than a first preset threshold and the battery voltage is lower than a second preset threshold, the power conversion device determines the pulse charging information according to the battery temperature and the SOC.

[0142] Optionally, there are multiple ways to determine pulse charging information based on battery temperature and SOC. As an example, a mapping relationship between battery temperature, SOC, and pulse charging information can be determined, and specific pulse charging information can be determined based on this mapping relationship. This mapping relationship can be a mapping relationship obtained by fitting a large amount of experimental data, with high reliability and accuracy. The mapping relationship can specifically be a mapping table, a mapping diagram, or a mapping formula. Furthermore, in other examples, a dedicated neural network model can be trained based on a large amount of experimental data. This neural network model can output pulse charging information based on the input battery temperature and SOC.

[0143] In some embodiments, the pulse charging information includes but is not limited to: effective value of pulse current, peak value of pulse current, pulse voltage, pulse direction, pulse frequency, pulse pause, and pulse duration.

[0144] Step 422: The power conversion device determines first DC charging information according to the pulse charging information.

[0145] Specifically, the power conversion device may calculate first DC charging information corresponding to the pulse charging information based on the pulse charging information. The first DC charging information may include at least one of the following information: a required charging voltage, a required charging current, and a required charging mode. The required charging mode may be a constant current mode or a constant voltage mode.

[0146] Step 423: The power conversion device sends first DC charging information to the charging pile.

[0147] Optionally, in some embodiments, the first DC charging information may be sent to the charging pile as a charging requirement from the BMS. Optionally, the power conversion device may send the first DC charging information via a battery charging requirement (BCL) message. Alternatively, in other embodiments, the first DC charging information may be sent to the charging pile via other messages. This embodiment of the application does not specifically limit the message type and sending method.

[0148] Optionally, the above steps 421 to 423 may be Figure 3 The implementation method included in step 220 in FIG.

[0149] Step 431: The charging pile outputs a DC current to the power conversion device.

[0150] Step 432: The power conversion device converts the DC current into a pulse current.

[0151] Step 433: The power conversion device outputs a pulse current to the power battery.

[0152] Optionally, the above steps 431 to 433 may be Figure 3 The implementation method included in step 230.

[0153] Specifically, in the above steps, the charging pile outputs a DC current to the power conversion device. The power conversion device is used to convert the DC current into a pulse current and output it to the power battery to achieve pulse charging of the power battery. The pulse current is a pulse current generated by converting the DC current based on the above pulse charging information. The DC current is the DC current output by the charging pile to the power conversion device based on the above first DC charging information.

[0154] Through the technical solution of the embodiment of the present application, the power conversion equipment can determine the corresponding pulse charging information based on the state parameters of the power battery it obtains, and convert different pulse currents according to the pulse charging information to adapt to the different charging requirements of the power battery in different situations, with high flexibility and adaptability.

[0155] It is understandable that the above Figure 7 The charging method 400 may be a schematic flow chart of a method for setting the charging mode of a power conversion device to a pulse charging mode in an initial stage, ie, when the charging mode is not set.

[0156] When the power conversion device switches its charging mode from the DC charging mode to the pulse charging mode, or switches from other charging modes to the pulse charging mode, Figure 8 A schematic flowchart of a charging method 500 according to another embodiment of the present application is shown.

[0157] like Figure 8 As shown, the charging method 500 may include the following steps.

[0158] Step 510: The battery management system BMS sends battery status parameters of the power battery to the power conversion device. The status parameters include battery temperature and battery state of charge.

[0159] Optionally, the battery management system BMS may also send other parameters such as the battery voltage of the power battery to the power conversion device.

[0160] Optionally, the relevant technical solutions of step 510 can be found in the above Figure 7 The relevant description of step 410 is not repeated here.

[0161] Step 521: When the battery temperature is lower than a first preset threshold, the power conversion device sends a charging prohibition message to the charging pile.

[0162] Specifically, in this step, the charging prohibition message is used to instruct the charging pile to stop outputting direct current to the power conversion device.

[0163] Optionally, in other implementations of this step, when the battery temperature is lower than a first preset threshold and the battery voltage is lower than a second preset threshold, the power conversion device sends a charging prohibition message to the charging pile.

[0164] Optionally, before step 521, the power conversion device may send a battery charging requirement message (BCL) to the charging pile. Specifically, in the requirement message, the required voltage may be the total voltage of the power battery, and the required current is set to the minimum output current of the charging pile, for example, a current value of 10A.

[0165] Through the technical solution of the embodiment of the present application, before the power conversion device sends a charging prohibition message to the charging pile, it first sends a smaller demand current to the charging pile, and then prohibits the charging pile from outputting, thereby preventing the charging prohibition message from being sent directly to the charging pile. The charging pile can be prohibited from outputting current more quickly, and the impact on the entire charging system is relatively small.

[0166] Step 522: The power conversion device obtains a voltage difference between the input terminal and the output terminal, and determines whether the voltage difference is less than a third preset threshold.

[0167] Optionally, in this step, the power conversion device switches its charging mode from a DC charging mode to a pulse charging mode, which involves controlling the switching of a relay. Since an excessively large voltage difference between the input and output terminals of the power conversion device can easily damage the relay, affecting the normal operation of the power conversion device. Therefore, to protect the relay and ensure the performance of the power conversion device, before controlling the relay switching, the power conversion device may also obtain the voltage difference between its input and output terminals and determine whether the voltage difference is less than a third preset threshold. If the voltage difference is less than the third preset threshold, the power conversion device performs subsequent actions. If the voltage difference is not less than the third preset threshold, the power conversion device stops outputting. Alternatively, the power conversion device may wait for a period of time until the voltage difference is less than the third preset threshold. As an example, the third preset threshold includes, but is not limited to, 10V.

[0168] Optionally, in some embodiments, the power conversion device can directly detect the voltage difference between its input and output ends, or, in other embodiments, the power conversion device can receive the voltage value sent by the power battery and the voltage value sent by the charging pile, and use the voltage value sent by the power battery as the voltage of its output end, and use the voltage value sent by the charging pile as the voltage of its input end.

[0169] Specifically, if the charging mode of the power conversion device is switched from the DC charging mode to the pulse charging mode, when the voltage difference between the input and output terminals of the power conversion device is less than a third preset threshold, the state of the relay in the power conversion device changes, for example, Figure 2 The second relay K2 and the third relay K3 in the circuit are closed, and then the following pre-charging step is performed.

[0170] Step 523: The power conversion device performs pre-charging.

[0171] Specifically, the power conversion module of a power conversion device contains large-capacity capacitors in the high-voltage charging circuits at its input and output ends. The moment the power conversion module is connected to the high-voltage circuit, the high voltage in the charging circuit charges the large-capacity capacitors, generating a large pulse current. This large pulse current can damage components in the power conversion device or power battery, such as the high-voltage contactor.

[0172] Therefore, when the power conversion device switches from DC charging mode to pulse charging mode, after the power conversion device sends a charging prohibition message to the charging station, the capacitor in the power conversion device needs to be pre-charged. Optionally, the battery voltage of the power battery can be used to pre-charge the capacitor. In this way, during the subsequent charging of the power battery, the capacitor will no longer induce a large pulse current, thereby ensuring the normal and safe charging process.

[0173] Furthermore, if the precharge is successful, Figure 2 The first relay K1 in the charging station is disconnected to disconnect the DC connection between the charging pile and the power battery.

[0174] Step 524: The power conversion device determines pulse charging information according to the state parameters.

[0175] Step 525: The power conversion device determines first DC charging information according to the pulse charging information.

[0176] Step 526: The power conversion device sends the first DC charging information and the charging permission message to the charging pile.

[0177] Specifically, in step 526 , in addition to sending the first DC charging information to the charging pile, the power conversion device also sends a charging permission message to the charging pile. The charging permission message is used to indicate that the charging pile can output DC current.

[0178] Optionally, other related solutions of steps 524 to 526 can be found in the above Figure 7 The relevant descriptions of steps 421 to 423 are not repeated here.

[0179] Step 531: The charging pile outputs a DC current to the power conversion device.

[0180] Step 532: The power conversion device converts the DC current into a pulse charging current.

[0181] Step 533: The power conversion device outputs a pulse charging current to the power battery.

[0182] Optionally, the above steps 531 to 533 can refer to the above Figure 7 The relevant descriptions of steps 431 to 433 are not repeated here.

[0183] Combined with the above Figure 8 The following describes the technical solution for switching the charging mode of the power conversion device from the DC charging mode to the pulse charging mode in the embodiment of the present application. Figure 9The following describes a technical solution for switching a power conversion device from a pulse charging mode to a DC charging mode in an embodiment of the present application.

[0184] Figure 9 A schematic flowchart of a charging method 600 according to another embodiment of the present application is shown.

[0185] like Figure 9 As shown, the charging method 600 may include the following steps.

[0186] Step 611: The battery management system BMS sends second DC charging information of the power battery to the power conversion device.

[0187] Optionally, in some embodiments, the battery management system (BMS) may send second DC charging information of the power battery to the power conversion device via a battery charging requirement (BCL) message. The second DC charging information is charging information determined by the battery management system (BMS) based on current state parameters of the power battery. The second DC charging information may include at least one of the following information: required charging voltage, required charging current, and required charging mode. The required charging mode may be a constant current mode or a constant voltage mode.

[0188] Alternatively, in some other implementations, the first DC charging information may also be sent to the power conversion device via other messages. The embodiment of the present application does not specifically limit the message type and sending method.

[0189] Step 612: The battery management system BMS sends the battery status parameters of the power battery to the power conversion device. The status parameters include the battery temperature and the battery state of charge.

[0190] Optionally, the battery management system BMS may also send other parameters such as the battery voltage of the power battery to the power conversion device.

[0191] Optionally, the relevant technical solutions of step 612 can be found in the above Figure 7 The relevant description of step 410 is not repeated here.

[0192] Step 621: When the battery temperature is not lower than a first preset threshold, the power conversion device stops outputting pulse current to the power battery.

[0193] Specifically, in this step, when the battery temperature is not lower than the first preset threshold value, it indicates that the current state of the power battery can receive DC power, and DC charging will not affect the power battery. At this time, the power conversion device stops outputting pulse power to the power battery, and in subsequent steps it realizes outputting DC power to the power battery, thereby improving the charging speed and charging efficiency of the power battery when the battery temperature is not lower than the first preset threshold value.

[0194] Optionally, in another embodiment of this step, when the battery temperature is not lower than a first preset threshold, or when the battery voltage is not lower than a second preset threshold, the power conversion device stops outputting the pulse current to the power battery.

[0195] It is understandable that in this step, the operating status of the functional modules in the power conversion device can be controlled through communication signaling and software programs to enable the power conversion device to stop outputting pulse current to the power battery.

[0196] It is also understandable that in this step, the power conversion device can also be controlled by controlling the relay in the power conversion device to stop outputting the pulse current to the power battery. As an example, for example, by controlling Figure 2 The third relay K3 in the power conversion device is disconnected, so that the power conversion device stops outputting pulse current to the power battery. Figure 2 The second relay K2 and the third relay K3 are both disconnected, so that the power conversion device stops outputting pulse current to the power battery.

[0197] Step 622: The power conversion device sends the second DC charging information to the charging pile.

[0198] Specifically, in this step, the power conversion device directly forwards the second DC charging information sent by the battery management system BMS to the charging pile, for example, forwards the battery charging requirement (BCL) message to the charging pile.

[0199] Optionally, the above steps 612 and 622 may be Figure 5 The implementation method included in step 240 in FIG.

[0200] Step 631: The charging pile outputs direct current to the power battery through the power conversion device.

[0201] Specifically, in this step, by closing the first relay K1 and disconnecting the second relay K2 and the third relay K3, a direct electrical connection is achieved between the charging pile and the power battery, so that the charging pile outputs DC current to the power battery through the power conversion device. In other words, it can also be understood that the power conversion device directly transmits the DC current of the charging pile to the power battery.

[0202] Specifically, in this step, the DC current output by the charging pile is the DC power output by the charging pile according to the above-mentioned second DC charging information, which can meet the charging demand of the power battery.

[0203] Optionally, the above step 631 may be Figure 5 The embodiment included in step 250 in FIG.

[0204] Figure 10A schematic flowchart of a charging method 700 according to another embodiment of the present application is shown.

[0205] like Figure 10 As shown, the charging method 700 may include the following steps.

[0206] Step 711: The battery management system BMS sends second DC charging information of the power battery to the power conversion device.

[0207] Step 712: The battery management system BMS sends the battery status parameters of the power battery to the power conversion device. The status parameters include the battery temperature and the battery state of charge.

[0208] Optionally, the battery management system BMS may also send other parameters such as the battery voltage of the power battery to the power conversion device.

[0209] Step 721: When the battery temperature is not lower than a first preset threshold, the power conversion device sends a charging prohibition message to the charging pile.

[0210] Specifically, in this step, the charging prohibition message is used to instruct the charging pile to stop outputting direct current to the power conversion device.

[0211] Optionally, in other implementations of this step, when the battery temperature is not lower than a first preset threshold or the battery voltage is not lower than a second preset threshold, the power conversion device sends a charging prohibition message to the charging pile.

[0212] Optionally, before step 721, the power conversion device may send a battery charging requirement message (BCL) to the charging pile. Specifically, in the requirement message, the required voltage may be the total voltage of the power battery, and the required current is set to the minimum output current of the charging pile, for example, a current value of 10A.

[0213] Through the technical solution of the embodiment of the present application, before the power conversion device stops outputting pulse current to the power battery, it first sends a smaller demand current to the charging pile, and then prohibits the charging pile from outputting, thereby preventing the charging prohibition message from being sent directly to the charging pile. The charging pile can be prohibited from outputting current more quickly, and the impact on the entire charging system is relatively small.

[0214] Step 722: The power conversion device stops outputting pulse current to the power battery.

[0215] Specifically, in this step, the functional modules in the power conversion device may be controlled to stop working, so that the power conversion device stops outputting pulse current to the power battery.

[0216] Step 723: The power conversion device obtains a voltage difference between its input terminal and output terminal, and determines whether the voltage difference is less than a fourth preset threshold.

[0217] Optionally, in this step, when the power conversion device switches its charging mode from a pulse charging mode to a DC charging mode, if the switching control of the relay is involved, a large voltage difference between the input and output terminals of the power conversion device may easily damage the relay, affecting the normal operation of the power conversion device. Therefore, in order to protect the relay and ensure the performance of the power conversion device, before controlling the relay switching, the power conversion device may also obtain the voltage difference between its input and output terminals and determine whether the voltage difference is less than a fourth preset threshold. If the voltage difference is less than the fourth preset threshold, the power conversion device performs subsequent actions. If the voltage difference is not less than the fourth preset threshold, the power conversion device stops outputting, or it may wait for a period of time until the voltage difference is less than the fourth preset threshold. As an example, the fourth preset threshold includes, but is not limited to, 10V.

[0218] Specifically, if the charging mode of the power conversion device is switched from the pulse charging mode to the DC charging mode, when the voltage difference between the input and output terminals of the power conversion device is less than a fourth preset threshold, the state of the relay in the power conversion device changes, for example, Figure 2 The first relay K1 is closed, and the second relay K2 and the third relay K3 are opened.

[0219] Furthermore, when the voltage difference between the input terminal and the output terminal of the power conversion device is less than the fourth preset threshold and the first relay K1 is closed, the following steps 724 and 731 are performed.

[0220] Step 724: The power conversion device sends the second DC charging information and the charging permission message to the charging pile.

[0221] Specifically, in this step, in addition to sending the second DC charging information to the charging pile, the power conversion device also sends a charging permission message to the charging pile, where the charging permission message is used to indicate that the charging pile can output DC current.

[0222] Step 731: The charging pile outputs direct current to the power battery through the power conversion device.

[0223] Specifically, in this step, when the voltage difference between the input and output ends of the power conversion device is less than the fourth preset threshold, the power conversion device outputs the DC current output by the charging pile according to the above-mentioned second DC charging information to the power battery to charge the power battery, which can meet the charging needs of the power battery.

[0224] Optionally, the relevant solutions of the embodiments of the present application can be found in the above Figure 9 The relevant description in , I will not go into details here.

[0225] The above describes various embodiments of the charging method provided by the present application using a power conversion device as the execution subject. The following describes the charging process of the power conversion device by taking the power conversion device including a control unit and a power unit as an example. For example, the power conversion device can be Figure 2 The power conversion device 110 includes a control unit 112 and a power unit 111.

[0226] Figure 11 A schematic flow chart of a charging method of a power conversion device according to another embodiment of the present application is shown. The power conversion device is used to convert power between a charging pile and a power battery, and includes: a control unit and a power unit.

[0227] Return to the previous reference Figure 3 The charging method 200 shown, Figure 11 Another schematic flow chart of the charging method 200 provided in an embodiment of the present application is shown.

[0228] like Figure 11 As shown, the above step 210 may include: Step 211: The control unit obtains the battery status parameter of the power battery, and the status parameter includes the battery temperature.

[0229] The above step 220 may include: Step 221: when the battery temperature is lower than a first preset threshold, the control unit sets the charging mode of the power unit to a pulse charging mode.

[0230] Specifically, in this step, in the pulse charging mode, the control unit controls the operation of the power unit so that the power unit can generate a pulse voltage or a pulse current.

[0231] Optionally, the control unit controls the software program and / or hardware circuit in the power unit, thereby controlling the operating state of the power unit, so that the power unit can convert the direct current received from the charging pile into pulse electricity.

[0232] As an example, in Figure 2 In the power conversion device 110 shown, the control unit controls the second relay K2 and the third relay K3 to close, and controls the first relay K1 to disconnect, so as to connect the power conversion module between the charging pile 120 and the power battery 131, so that the power conversion module operates and converts the DC power received from the charging pile into pulse power.

[0233] The above step 230 may include: Step 231: In the pulse charging mode, the power unit converts the charging power of the charging pile and then charges the power battery.

[0234] Specifically, in this step, the power unit in the power conversion device is used to convert the charging power of the charging pile and output the converted charging power to the power battery to charge the power battery. In the pulse charging mode, the charging power converted by the power conversion device is a pulse charging voltage or a pulse charging current.

[0235] Specifically, in the embodiment of the present application, the power conversion device realizes the use of a pulse charging mode to charge the power battery through the cooperation between the control unit and the power unit. Figure 3 The relevant description in will not be repeated here.

[0236] Similarly, for the above Figure 5 In the method 200 shown in FIG, the above step 240 may include: Step 241: when the battery temperature is not lower than a first preset threshold, the control unit switches the charging mode of the power unit from the pulse charging mode to the DC charging mode.

[0237] Specifically, in this step, in the DC charging mode, the control unit controls the operation of the power unit so that the power unit can output a constant voltage or a constant current.

[0238] As an example, the control unit can control the operating status of each functional module in the power unit by controlling the software program and / or hardware circuit in the power unit, so that the power unit can output the DC power it receives from the charging pile directly to the power battery.

[0239] For example, in Figure 2 In the power conversion device 110 shown, the control unit can control the second relay K2 and the third relay K3 to disconnect, and control the first relay K1 to close, so as to achieve a direct electrical connection between the charging pile 120 and the power battery 131, so that the power unit 111 can directly output the DC power it receives from the charging pile 120 to the power battery 131.

[0240] Furthermore, in Figure 2 In the power conversion device 110 shown, the control unit can also control the power conversion module to stop running, so as to further enhance the reliability and flexibility during the charging mode switching process.

[0241] The above step 250 may include: Step 251: In the DC charging mode, the power unit transmits the charging power of the charging pile to the power battery.

[0242] Similarly, for the above Figure 4 and Figure 6In the method 300 shown in FIG, the above step 310 may include: Step 311: The control unit obtains battery status parameters of the power battery, where the status parameters include battery temperature and battery voltage.

[0243] The above step 320 may include: Step 321: when the battery temperature is lower than a first preset threshold and the battery voltage is lower than a second preset threshold, the control unit sets the charging mode of the power unit to a pulse charging mode.

[0244] The above step 330 may include: Step 331: In the pulse charging mode, the power unit converts the charging power of the charging pile and then charges the power battery.

[0245] The above step 340 may include: Step 341: when the battery temperature is not lower than a first preset threshold, or the battery voltage is not lower than a second preset threshold, the control unit switches the charging mode of the power unit from the pulse charging mode to the DC charging mode.

[0246] The above step 350 may include: Step 351: In the DC charging mode, the power unit transmits the charging power of the charging pile to the power battery.

[0247] Specifically, in the embodiment of the present application, the power conversion device switches the pulse charging mode to the DC charging mode to charge the power battery through the cooperation between the control unit and the power unit. Figures 4 to 6 The relevant description in will not be repeated here.

[0248] Return Reference Figure 7 The charging method 400 shown in FIG. Figure 12 Another schematic flowchart of a charging method 400 provided in an embodiment of the present application is shown.

[0249] like Figure 12 As shown, the above step 410 may include: Step 4101: The battery management system BMS sends battery status parameters of the power battery to the control unit, and the status parameters include battery temperature and battery state of charge.

[0250] Optionally, the battery management system BMS may also send other parameters such as the battery voltage of the power battery to the control unit.

[0251] Optionally, in an embodiment of the present application, the battery temperature of the power battery can be sent to the control unit via a power battery status information message (BSM), and parameters such as the battery state of charge SOC and battery voltage of the power battery can be sent to the control unit via a battery charging status message (BCS).

[0252] The above step 421 may include: Step 4211: when the battery temperature is lower than a first preset threshold, the control unit determines pulse charging information according to the state parameter.

[0253] Specifically, in this step, when the battery temperature is lower than the first preset threshold, the control unit determines the pulse charging information based on the battery temperature and SOC, which can adapt to both the current temperature and SOC of the power battery.

[0254] Alternatively, in another embodiment of this step, when the battery temperature is lower than a first preset threshold and the battery voltage is lower than a second preset threshold, the control unit determines the pulse charging information according to the battery temperature and the SOC.

[0255] The above step 422 may include: Step 4221: The control unit sends pulse charging information to the power unit.

[0256] Optionally, the control unit can determine the pulse charging information based on the battery temperature and SOC in a variety of ways. As an example, a mapping relationship between the battery temperature, SOC, and pulse charging information can be determined, and specific pulse charging information can be determined based on this mapping relationship. This mapping relationship can be a mapping relationship obtained by fitting a large amount of experimental data, which has high reliability and accuracy. Furthermore, in other examples, a dedicated neural network model can be trained based on a large amount of experimental data. This neural network model can output pulse charging information based on the input battery temperature and SOC.

[0257] Step 4222: The power unit determines first DC charging information according to the pulse charging information.

[0258] Specifically, the power unit may determine first DC charging information corresponding to the pulse charging information based on the pulse charging information. The first DC charging information may include at least one of the following information: a required charging voltage, a required charging current, and a required charging mode. The required charging mode may be a constant current mode or a constant voltage mode.

[0259] Step 4223: The power unit sends first DC charging information to the control unit.

[0260] The above step 423 may include: Step 4231: The control unit sends first DC charging information to the charging pile.

[0261] Specifically, the control unit forwards the first DC charging information received from the power unit to the charging pile.

[0262] Optionally, in some embodiments, the first DC charging information may be sent to the charging pile as a charging requirement from the BMS. Optionally, the control unit may send the first DC charging information via a battery charging requirement (BCL) message. Alternatively, in other embodiments, the first DC charging information may be sent to the charging pile via other messages. This embodiment of the application does not specifically limit the message type and sending method.

[0263] The above step 431 may include: Step 4311: The charging pile outputs a direct current to the power unit.

[0264] The above step 432 may include: Step 4321: The control unit sends a start output message to the power unit.

[0265] Specifically, the startup output message is used to instruct the power unit to start running to implement the subsequent step 4322.

[0266] Step 4322: The power unit converts the DC current into a pulse current.

[0267] The above step 433 may include: Step 4331: the power unit outputs a pulse current to the power battery.

[0268] Specifically, the specific implementation of the embodiment of the present application can be found in the above Figure 7 For the sake of brevity, the relevant description of the charging method 400 shown in FIG. 4 is not repeated here in detail.

[0269] Return Reference Figure 8 The charging method 500 shown in FIG. Figure 13 Another schematic flowchart of a charging method 500 provided in an embodiment of the present application is shown.

[0270] like Figure 13 As shown, the above step 510 may include: Step 5101: The battery management system BMS sends battery status parameters of the power battery to the control unit, and the status parameters include battery temperature and battery state of charge.

[0271] The above step 521 may include: Step 5211: when the battery temperature is lower than a first preset threshold, the control unit sends a charging prohibition message to the charging pile.

[0272] Optionally, in other implementations of this step, when the battery temperature is lower than a first preset threshold and the battery voltage is lower than a second preset threshold, the control unit sends a charging prohibition message to the charging pile.

[0273] Optionally, before step 5211, the control unit may send a battery charging requirement message (BCL) to the charging pile. Specifically, in the requirement message, the required voltage may be the total voltage of the power battery, and the required current is set to the minimum output current of the charging pile, for example, a current value of 10A.

[0274] The above step 522 may include: Step 5221: The control unit obtains the voltage difference between the input end and the output end, and determines whether the voltage difference is less than a third preset threshold.

[0275] Optionally, in this step, the control unit switches the power unit's charging mode from a DC charging mode to a pulse charging mode, which involves controlling the on / off switching of a relay. Since an excessively large voltage difference between the power unit's input and output terminals can easily damage the relay, affecting the normal operation of the power conversion device. Therefore, to protect the relay and ensure the performance of the power conversion device, before controlling the relay's on / off switching, the control unit may also obtain the voltage difference between the power unit's input and output terminals, determine whether the voltage difference is less than a third preset threshold, and if so, execute subsequent actions. If the voltage difference is not less than the third preset threshold, the control unit may control the power unit to stop outputting power, or may wait for a period of time until the voltage difference is less than the third preset threshold.

[0276] Optionally, in some embodiments, the control unit may directly detect the voltage difference between the input and output ends of the power unit, or, in other embodiments, the control unit may receive the voltage value sent by the power battery and the voltage value sent by the charging pile, and use the voltage value sent by the power battery as the voltage of the output end of the power unit, and use the voltage value sent by the charging pile as the voltage of the input end of the power unit.

[0277] Specifically, if the charging mode of the power unit is switched from the DC charging mode to the pulse charging mode, when the voltage difference between the input and output terminals of the power unit is less than a third preset threshold, the state of the relay in the power conversion device changes, for example, Figure 2 The second relay K2 and the third relay K3 in the power supply are closed, electrically connecting the power unit to the charging pile and the power battery.

[0278] The above step 523 may include the following steps.

[0279] Step 5231: The control unit sends a pre-charge instruction to the power unit.

[0280] Step 5232: The power unit is pre-charged.

[0281] Step 5233: The power unit sends its pre-charge status to the control unit.

[0282] Step 5234: The control unit determines whether the power unit is pre-charged successfully.

[0283] After the charging pile stops outputting DC current and the second relay K2 and the third relay K3 are closed, the control unit sends a pre-charge instruction to the power unit. The power unit starts pre-charging according to the pre-charge instruction, which includes charging the capacitor in the power unit.

[0284] During the pre-charging process of the power unit, the power unit sends its pre-charging status to the control unit in real time. The control unit determines whether the power unit is pre-charged successfully based on the pre-charging status. If successful, the control unit performs subsequent operations. If unsuccessful, the control unit controls the power unit to stop output.

[0285] Furthermore, if the pre-charge is successful, the control unit controls Figure 2 The first relay K1 in the charging station is disconnected to disconnect the DC connection between the charging pile and the power battery.

[0286] The above step 524 may include: Step 5241: The control unit determines pulse charging information according to the state parameters.

[0287] The above step 525 may be performed as follows.

[0288] Step 5251: The control unit sends pulse charging information to the power unit.

[0289] Step 5252: The power unit determines first DC charging information according to the pulse charging information.

[0290] Step 5253: The power unit sends first DC charging information to the control unit.

[0291] The above step 526 may include: Step 5261: The control unit sends first DC charging information to the charging pile.

[0292] The above step 531 may include: Step 5311: the charging pile outputs a direct current to the power unit.

[0293] The above step 532 may include: step 5321: the control unit sends a start output message to the power unit; step 5322: the power unit converts the direct current into a pulse current.

[0294] The above step 533 may include: Step 5331: The power unit outputs a pulse current to the power battery.

[0295] Specifically, the specific implementation of the embodiment of the present application can be found in the above Figure 8 For the sake of brevity, the relevant description of the charging method 500 shown in FIG. 5 is not repeated here in detail.

[0296] Return Reference Figure 9 The charging method 600 shown in FIG. Figure 14 Another schematic flowchart of a charging method 600 provided in an embodiment of the present application is shown.

[0297] like Figure 14 As shown, the above step 611 may include: Step 6111: The battery management system BMS sends second DC charging information of the power battery to the control unit.

[0298] Optionally, in some embodiments, the battery management system BMS may send the second DC charging information of the power battery to the control unit via a battery charging requirement (BCL) message.

[0299] Alternatively, in some other implementations, the first DC charging information may also be sent to the control unit via other messages. The embodiment of the present application does not specifically limit the message type and sending method.

[0300] The above step 612 may include: Step 6121: The battery management system BMS sends the battery status parameters of the power battery to the control unit, where the status parameters include the battery temperature and the battery state of charge.

[0301] Optionally, the battery management system BMS may also send other parameters such as the battery voltage of the power battery to the control unit.

[0302] The above step 621 may include: Step 6211: when the battery temperature is not lower than a first preset threshold, the control unit sends an output prohibition message to the power unit.

[0303] Specifically, in this step, when the battery temperature is not lower than the first preset threshold, the control unit sends an output prohibition message to the power unit to control the power unit to stop outputting the pulse current.

[0304] Optionally, in another embodiment of this step, when the battery temperature is not lower than a first preset threshold, or when the battery voltage is not lower than a second preset threshold, the control unit sends an output prohibition message to the power unit to control the power unit to stop outputting pulse current to the power battery.

[0305] Optionally, the output prohibition message may include multiple types, for example, a pause output message and a stop output message. The pause output message is used to instruct the power unit to temporarily stop outputting pulse current. In this state, the power unit can resume outputting pulse current if it receives a start output message. However, the stop output message is used to instruct the capacitor in the power unit to perform a power-down discharge process, and the power unit enters a dormant state.

[0306] Optionally, the output disable message and the output enable message sent by the control unit to the power unit are carried in the same type of message. For example, in this message, the output enable message is represented by "1", the output disable message is represented by "2", and the output stop message is represented by "3".

[0307] The above step 622 may include: Step 6221: The control unit sends the second DC charging information to the charging pile.

[0308] The above step 631 may include: Step 6311: the charging pile outputs direct current to the power battery through the power unit.

[0309] Specifically, in this step, by closing the first relay K1 in the power unit and disconnecting the second relay K2 and the third relay K3, a direct electrical connection is achieved between the charging pile and the power battery, so that the charging pile outputs DC current to the power battery through the power unit.

[0310] Return Reference Figure 10 The charging method 600 shown in FIG. Figure 15 Another schematic flowchart of a charging method 700 provided in an embodiment of the present application is shown.

[0311] like Figure 15 As shown, the above step 711 may include: Step 7111: The battery management system BMS sends second DC charging information of the power battery to the power conversion device.

[0312] The above step 712 may include: Step 7121: The battery management system BMS sends the battery status parameters of the power battery to the control unit, where the status parameters include the battery temperature and the battery state of charge.

[0313] Optionally, the battery management system BMS may also send other parameters such as the battery voltage of the power battery to the control unit.

[0314] The above step 721 may include: Step 7211: when the battery temperature is not lower than a first preset threshold, the control unit sends a charging prohibition message to the charging pile.

[0315] Optionally, in other implementations of this step, when the battery temperature is not lower than a first preset threshold or the battery voltage is not lower than a second preset threshold, the control unit sends a charging prohibition message to the charging pile.

[0316] Optionally, before step 7211, the control unit may send a battery charging requirement message (BCL) to the charging pile. Specifically, in the requirement message, the required voltage may be the total voltage of the power battery, and the required current is set to the minimum output current of the charging pile, for example, a current value of 10A.

[0317] The above step 722 may include: Step 7221: The control unit sends an output prohibition message to the power unit.

[0318] Specifically, the control unit sends an output prohibition message to the power unit to control the power unit to stop outputting the pulse current.

[0319] Optionally, the relevant technical solutions in this step can be found above Figure 14 The description of step 6211 will not be repeated here.

[0320] The above step 723 may include: Step 7231: The control unit obtains a voltage difference between the input end and the output end of the power unit, and determines whether the voltage difference is less than a fourth preset threshold.

[0321] If the voltage difference is less than the fourth preset threshold, the control unit continues to perform subsequent actions. If the voltage difference is not less than the fourth preset threshold, the control unit may continue to wait until the voltage difference is less than the fourth preset threshold. In this case, if the waiting time of the control unit is greater than a certain threshold, the control unit may send a charging stop message to the power unit to cause the capacitor in the power unit to perform power-down discharge.

[0322] Specifically, when the voltage difference between the input and output terminals of the power unit is less than a fourth preset threshold, the state of the relay in the power conversion device changes, for example, Figure 2 The first relay K1 is closed, and the second relay K2 and the third relay K3 are opened to disconnect the electrical connection between the power unit and the charging pile, and the electrical connection between the power unit and the power battery, and directly connect the charging pile and the power battery.

[0323] Furthermore, when the voltage difference between the input terminal and the output terminal of the power unit is less than the fourth preset threshold value and the first relay K1 is closed, the following step 7241 is executed.

[0324] The above step 724 may include: Step 7241: The control unit sends the second DC charging information and the charging permission message to the charging pile.

[0325] The above step 731 may include: Step 7311: the charging pile outputs direct current to the power battery through the power unit.

[0326] It should be noted that in addition to providing a charging method using a power conversion device as the execution subject, this application also provides a charging method using a charging pile and a BMS as the execution subject. Specifically, the charging method using a charging pile and a BMS as the execution subject can refer to the relevant descriptions of the various method embodiments above, and will not be detailed here.

[0327] Combined with the above Figures 3 to 15The specific embodiment of the charging method provided by this application is described below. Figures 16 to 18 The specific embodiments of the charging device provided in this application are described. It can be understood that the relevant descriptions in the following embodiments can refer to the aforementioned embodiments, and for the sake of brevity, they will not be repeated.

[0328] Figure 16 FIG. 8 shows a schematic structural diagram of a power conversion device 800 according to an embodiment of the present application. Figure 16 As shown, the power conversion device 800 includes: a receiving module 810 , a sending module 820 and a processing module 830 .

[0329] In one embodiment of the present application, the receiving module 810 is used to receive status parameters of the power battery, which include the battery temperature; the processing module 830 is used to set the charging mode to a pulse charging mode when the battery temperature is lower than a first preset threshold; in this pulse charging mode, the processing module 830 is used to convert the charging power of the charging pile and then charge the power battery. The pulse charging mode is a charging mode that outputs a pulse voltage or a pulse current.

[0330] Optionally, the processing module 830 is also used to switch the charging mode from the pulse charging mode to the DC charging mode when the battery temperature is not lower than a first preset threshold; in the DC charging mode, the processing module 830 transmits the charging power of the charging pile to the power battery to charge the power battery, wherein the DC charging mode is a charging mode that outputs a constant voltage or a constant current.

[0331] Optionally, the state parameter further includes: battery voltage; the processing module 830 is configured to set the charging mode to the pulse charging mode when the battery temperature is lower than a first preset threshold and the battery voltage is lower than a second preset threshold.

[0332] Optionally, the state parameter further includes: battery voltage, and the processing module 830 is configured to switch the charging mode from the pulse charging mode to the DC charging mode when the battery temperature is not lower than a first preset threshold or the battery voltage is not lower than a second preset threshold.

[0333] In the process of the processing module 830 being used to set the charging mode to the pulse charging mode, optionally, the state parameter also includes the battery state of charge; the sending module 820 is used to send first DC charging information to the charging pile, and the first DC charging information is determined by the processing module 830 based on the pulse charging information, wherein the pulse charging information includes at least one of the following information: pulse current information, pulse voltage information, pulse direction information, pulse frequency information and pulse time information, and the pulse charging information is determined by the processing module 830 based on the battery temperature and the battery state of charge; in the pulse charging mode, the processing module 830 is used to output a pulse current to the power battery, wherein the pulse current is generated by converting the DC current based on the pulse charging information, and the DC current is the DC current output by the charging pile to the processing module 830 based on the first DC charging information.

[0334] Optionally, before the processing module 830 sets the charging mode to the pulse charging mode, the sending module 820 is further configured to send a charging prohibition message to the charging pile, where the charging prohibition message is configured to instruct the charging pile to stop outputting direct current to the processing module 830 .

[0335] Optionally, after the sending module 820 is used to send a charging prohibition message to the charging pile, the processing module 830 is further used to perform pre-charging.

[0336] Optionally, the processing module 830 is configured to obtain a voltage difference between its input terminal and its output terminal; if the voltage difference is less than a third preset threshold, the processing module 830 performs pre-charging.

[0337] During the process of the processing module 830 being used to switch the charging mode from the pulse charging mode to the DC charging mode, optionally, the processing module 830 is used to stop outputting the pulse current to the power battery; the receiving module 810 is also used to receive second DC charging information of the power battery, and the sending module 820 is also used to send the second DC charging information to the charging pile; the processing module 830 is used to output the DC current output by the charging pile according to the second DC charging information to the power battery to charge the power battery.

[0338] Optionally, before the processing module 830 is used to stop outputting pulse current to the power battery, the sending module 820 is further used to send a charging prohibition message to the charging pile, where the charging prohibition message is used to instruct the charging pile to stop outputting DC current to the power conversion device.

[0339] Optionally, the processing module 830 is used to obtain the voltage difference between its input end and output end; if the voltage difference is less than a fourth preset threshold, the processing module 830 is used to output the DC current output by the charging pile according to the second DC charging information to the power battery to charge the power battery.

[0340] Optionally, the state parameters of the power battery are parameters acquired by a battery management system of the power battery.

[0341] Figure 17 FIG. 1 shows a schematic diagram of a power conversion device 900 according to another embodiment of the present application. Figure 8 As shown, the power conversion device 900 includes: a control unit 910 and a power unit 920. Optionally, the control unit 910 may be Figure 2 As shown in the control unit 112, the power unit 920 may be Figure 2 The power unit 111 shown in FIG. 1 may include Figure 2 The power conversion module, the first relay K1, the second relay K2 and the third relay K3 shown in FIG.

[0342] Optionally, the power battery, battery management system BMS and charging pile mentioned below may correspond to Figure 2 The power battery 131, BMS 132 and charging pile 120 shown in FIG.

[0343] Specifically, in the power conversion device 900 provided in the embodiment of the present application, the control unit 910 is used to obtain the state parameters of the power battery, which include the battery temperature of the power battery; when the battery temperature is lower than a first preset threshold value, the control unit 910 is used to set the charging mode of the power unit 920 to a pulse charging mode. In this pulse charging mode, the power unit 920 converts the charging power of the power battery to the charging pile and then charges the power battery. The pulse charging mode is a charging mode that uses a pulse voltage or a pulse current.

[0344] Optionally, when the battery temperature is not lower than a first preset threshold, the control unit 910 is also used to: switch the charging mode of the power unit 920 from a pulse charging mode to a DC charging mode, in which the power unit 920 is used to transmit the charging power of the charging pile to the power battery to charge the power battery, wherein the DC charging mode is a charging mode that uses a constant voltage or a constant current.

[0345] Optionally, the state parameters of the power battery acquired by the control unit 910 also include: battery voltage. When the battery temperature is lower than a first preset threshold and the battery voltage is lower than a second preset threshold, the control unit 910 is configured to set the charging mode of the power unit 920 to a pulse charging mode.

[0346] Optionally, the status parameters of the power battery obtained by the control unit 910 also include: battery voltage. When the battery temperature is not lower than a first preset threshold or the battery voltage is not lower than a second preset threshold, the control unit 910 is used to switch the charging mode of the power unit 920 from a pulse charging mode to a DC charging mode.

[0347] In the process of the control unit 910 being used to set the charging mode of the power unit 920 to the pulse charging mode, optionally, the state parameter also includes the battery state of charge; the control unit 910 is used to determine the pulse charging information based on the battery temperature and the battery state of charge, and send the pulse charging information to the power unit 920, the pulse charging information including at least one of the following information: pulse current, pulse voltage, pulse direction, pulse frequency and pulse time; the power unit 920 is used to determine the first DC charging information corresponding to the pulse charging information based on the pulse charging information, and send the first DC charging information to the control unit 910; the control unit 910 is used to send the first DC charging information to the charging pile, and control the power unit 920 to output a pulse current to the power battery, wherein the pulse current is generated by converting the DC current based on the pulse charging information, and the DC current is the DC current output by the charging pile to the power unit 920 according to the first DC charging information.

[0348] Optionally, before the control unit 910 is used to set the charging mode of the power unit 920 to the pulse charging mode, the control unit 910 is also used to: send a charging prohibition message to the charging pile, wherein the charging prohibition message is used to instruct the charging pile to stop outputting DC current to the power unit 920.

[0349] Optionally, after the control unit 910 is used to send a charging prohibition message to the charging pile, the control unit 910 is further used to send a pre-charging instruction to the power unit 920, and the power unit 920 is used to perform pre-charging according to the pre-charging instruction.

[0350] Optionally, the power unit 920 is used to obtain the voltage at its input end and the voltage at its output end, and send the voltage at the input end and the voltage at the output end to the control unit 910; if the voltage difference between the input end and the output end is less than a third preset threshold, the control unit 910 is used to send a pre-charge instruction to the power unit 920.

[0351] In the process of the control unit 910 being used to switch the charging mode of the power unit 920 from the pulse charging mode to the DC charging mode, optionally, the control unit 910 is also used to obtain second DC charging information of the power battery, where the second DC charging information is DC charging information determined according to the state parameters of the power battery; the control unit 910 is used to control the power unit 920 to stop outputting pulse current; the control unit 910 is used to control the power unit 920 to output the DC current output by the charging pile to the power battery according to the second DC charging information.

[0352] Optionally, before the control unit 910 is used to control the power unit 920 to stop outputting pulse current, the control unit 910 is further used to: send a charging prohibition message to the charging pile, where the charging prohibition message is used to instruct the charging pile to stop outputting DC current to the power unit 920.

[0353] Optionally, the control unit 910 is used to obtain the voltage difference between the input and output ends of the power unit 920; if the voltage difference is less than a fourth preset threshold, the control unit 910 is used to control the power unit 920 to output the DC current output by the charging pile to the power battery according to the second DC charging information.

[0354] Optionally, the state parameters of the power battery are parameters acquired by a battery management system of the power battery.

[0355] Figure 18 FIG1 shows a schematic diagram of an electronic device 1000 according to another embodiment of the present application. Figure 18 As shown, the electronic device 1000 includes a memory 1010 and a processor 1020, wherein the memory 1010 is used to store computer programs, and the processor 1020 is used to read the computer programs and execute the methods of the various embodiments of the present application based on the computer programs.

[0356] Optionally, the electronic device 1000 may be used for any one or more of: a charging pile, a BMS, and a power conversion device. In the embodiments of the present application, in addition to the processor in the power conversion device reading the corresponding computer program and executing the corresponding charging method of the power conversion device in the various embodiments described above based on the computer program, the processor in the charging pile or BMS may also read the corresponding computer program and execute the corresponding charging method of the charging pile or BMS in the various embodiments described above based on the computer program.

[0357] In addition, embodiments of the present application further provide a readable storage medium for storing a computer program for executing the methods of the various embodiments of the present application. Optionally, the computer program may be a computer program in one or more of the power conversion device, charging pile, and BMS.

[0358] It should be understood that the specific examples in this article are only intended to help those skilled in the art better understand the embodiments of the present application, and are not intended to limit the scope of the embodiments of the present application.

[0359] It should also be understood that in the various embodiments of the present application, the size of the serial number of each process does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0360] It should also be understood that the various implementation methods described in this specification can be implemented individually or in combination, and the embodiments of the present application are not limited to this.

[0361] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be substituted with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A charging method, characterized in that: The method comprises: The power conversion device obtains state parameters of the power battery, where the state parameters include battery temperature; When the battery temperature is lower than a first preset threshold, the power conversion device sets the charging mode to a pulse charging mode; In the pulse charging mode, the power conversion device converts the charging power of the charging pile to charge the power battery. The pulse charging mode is a charging mode that outputs a pulse voltage or a pulse current. Before the power conversion device sets the charging mode to the pulse charging mode, the power conversion device also includes sending a battery charging demand message to the charging pile, in which the demand current is set to the minimum output current of the charging pile; the power conversion device sends a charging prohibition message to the charging pile, and the charging prohibition message is used to instruct the charging pile to stop outputting DC current to the power conversion device; The power conversion device includes a power unit and a control unit. The power unit includes a power conversion module, a first relay, a second relay, and a third relay. The power conversion module is connected to the charging pile and the power battery through the second relay and the third relay respectively. The charging pile and the power battery are connected to each other through the first relay. If the second relay and the third relay are both disconnected and the first relay is closed, the charging power output by the charging pile is directly transmitted to the power battery. The control unit controls the second relay and the third relay to close, and controls the first relay to open, so as to connect the power conversion module between the charging pile and the power battery, so that the power conversion module operates and converts the DC power received from the charging pile into pulse power.

2. The method according to claim 1, characterized in that The method further comprises: When the battery temperature is not lower than the first preset threshold, the power conversion device switches the charging mode from the pulse charging mode to the DC charging mode; In the DC charging mode, the power conversion device transmits the charging power of the charging pile to the power battery to charge the power battery, wherein the DC charging mode is a charging mode that outputs a constant voltage or a constant current.

3. The method according to claim 1 or 2, characterized in that The state parameters also include: battery voltage; When the battery temperature is lower than a first preset threshold, the power conversion device sets the charging mode to a pulse charging mode, including: When the battery temperature is lower than the first preset threshold and the battery voltage is lower than a second preset threshold, the power conversion device sets the charging mode to the pulse charging mode.

4. The method according to claim 2, characterized in that The state parameters also include: battery voltage, When the battery temperature is not lower than the first preset threshold, the power conversion device switches the charging mode from the pulse charging mode to the DC charging mode, including: When the battery temperature is not lower than the first preset threshold or the battery voltage is not lower than a second preset threshold, the power conversion device switches the charging mode from the pulse charging mode to the DC charging mode.

5. The method according to claim 1, characterized in that The state parameters also include battery state of charge; The power conversion device sets the charging mode to the pulse charging mode, including: The power conversion device sends first DC charging information to the charging pile, where the first DC charging information is determined by the power conversion device based on pulse charging information, wherein the pulse charging information includes at least one of the following information: pulse current information, pulse voltage information, pulse direction information, pulse frequency information, and pulse time information, and the pulse charging information is determined by the power conversion device based on the battery temperature and the battery state of charge; In the pulse charging mode, the power conversion device converts the charging power of the charging pile to charge the power battery, including: The power conversion device outputs a pulse current to the power battery, wherein the pulse current is generated by converting a DC current based on the pulse charging information, and the DC current is the DC current output by the charging pile to the power conversion device according to the first DC charging information.

6. The method according to claim 1, characterized in that After the power conversion device sends a charging prohibition message to the charging pile, the method further includes: The power conversion device is pre-charged.

7. The method according to claim 6, characterized in that The power conversion device performs pre-charging, including: The power conversion device obtains a voltage difference between an input terminal and an output terminal thereof; If the voltage difference is less than a third preset threshold, the power conversion device performs pre-charging.

8. The method according to claim 2 or 4, characterized in that The power conversion device switches the charging mode from the pulse charging mode to the DC charging mode, comprising: The power conversion device stops outputting pulse current to the power battery; The power conversion device obtains second DC charging information of the power battery and sends the second DC charging information to the charging pile; The power conversion device transmits the charging power of the charging pile to the power battery to charge the power battery, including: The power conversion device outputs the DC current output by the charging pile according to the second DC charging information to the power battery to charge the power battery.

9. The method according to claim 8, characterized in that Before the power conversion device stops outputting the pulse current to the power battery, the method further includes: The power conversion device sends a charging prohibition message to the charging pile, where the charging prohibition message is used to instruct the charging pile to stop outputting direct current to the power conversion device.

10. The method according to claim 9, characterized in that The power conversion device outputs the DC current output by the charging pile according to the second DC charging information to the power battery to charge the power battery, including: The power conversion device obtains a voltage difference between an input terminal and an output terminal thereof; If the voltage difference is less than a fourth preset threshold, the power conversion device outputs the DC current output by the charging pile according to the second DC charging information to the power battery to charge the power battery.

11. The method according to claim 1, wherein The power conversion device obtains the state parameters of the power battery, including: The power conversion device receives the status parameter of the power battery sent by the battery management system of the power battery.

12. A power conversion device, characterized in that: include: Control unit and power unit; The control unit is used to obtain state parameters of the power battery, where the state parameters include a battery temperature of the power battery; When the battery temperature is lower than a first preset threshold, the control unit is configured to set the charging mode of the power unit to a pulse charging mode. In the pulse charging mode, the power unit converts the charging power of the charging pile to charge the power battery. The pulse charging mode is a charging mode that uses a pulse voltage or a pulse current. Before the control unit is used to set the charging mode of the power unit to the pulse charging mode, the control unit is further used to: send a battery charging demand message to the charging pile, in which the demand current is set to the minimum output current of the charging pile; send a charging prohibition message to the charging pile, and the charging prohibition message is used to instruct the charging pile to stop outputting direct current to the power conversion device; The power unit includes a power conversion module, a first relay, a second relay, and a third relay. The power conversion module is connected to the charging pile and the power battery through the second relay and the third relay respectively. The charging pile and the power battery are connected to each other through the first relay. If the second relay and the third relay are both disconnected and the first relay is closed, the charging power output by the charging pile is directly transmitted to the power battery. The control unit controls the second relay and the third relay to close, and controls the first relay to open, so as to connect the power conversion module between the charging pile and the power battery, so that the power conversion module operates and converts the DC power received from the charging pile into pulse power.

13. The power conversion device according to claim 12, characterized in that When the battery temperature is not lower than a first preset threshold, the control unit is further configured to: The charging mode of the power unit is switched from the pulse charging mode to the DC charging mode. In the DC charging mode, the power unit is used to transmit the charging power of the charging pile to the power battery to charge the power battery, wherein the DC charging mode is a charging mode using a constant voltage or a constant current.

14. The power conversion device according to claim 12 or 13, characterized in that: The state parameters also include: battery voltage, When the battery temperature is lower than the first preset threshold and the battery voltage is lower than a second preset threshold, the control unit is configured to set the charging mode of the power unit to the pulse charging mode.

15. The power conversion device according to claim 13, wherein: The state parameters also include: battery voltage, When the battery temperature is not lower than the first preset threshold or the battery voltage is not lower than a second preset threshold, the control unit is configured to switch the charging mode of the power unit from the pulse charging mode to the DC charging mode.

16. The power conversion device according to claim 12, wherein: The state parameters also include battery state of charge; The control unit is configured to determine pulse charging information according to the battery temperature and the battery state of charge, and send the pulse charging information to the power unit, wherein the pulse charging information includes at least one of the following information: pulse current, pulse voltage, pulse direction, pulse frequency, and pulse time; The power unit is configured to determine, based on the pulse charging information, first DC charging information corresponding to the pulse charging information, and send the first DC charging information to the control unit; The control unit is used to send the first DC charging information to the charging pile and control the power unit to output a pulse current to the power battery, wherein the pulse current is generated by converting a DC current based on the pulse charging information, and the DC current is the DC current output by the charging pile to the power unit according to the first DC charging information.

17. The power conversion device according to claim 12, wherein: After the control unit is used to send a charging prohibition message to the charging pile, The control unit is further configured to send a pre-charge instruction to the power unit; The power unit is used to perform pre-charging according to the pre-charging instruction.

18. The power conversion device according to claim 17, characterized in that The control unit is used to obtain the voltage difference between the input end and the output end of the power unit; If the voltage difference is less than a third preset threshold, the control unit is configured to send a pre-charge instruction to the power unit.

19. The power conversion device according to claim 13 or 15, characterized in that: The control unit is further configured to obtain second DC charging information of the power battery; The control unit is used to control the power unit to stop outputting pulse current; The control unit is used to control the power unit to output the DC current output by the charging pile according to the second DC charging information to the power battery.

20. The power conversion device according to claim 19, characterized in that Before the control unit is used to control the power unit to stop outputting the pulse current, the control unit is further used to: A charging prohibition message is sent to the charging pile, where the charging prohibition message is used to instruct the charging pile to stop outputting direct current to the power unit.

21. The power conversion device according to claim 20, characterized in that The control unit is used to obtain the voltage difference between the input end and the output end of the power unit; If the voltage difference is less than a fourth preset threshold, the control unit is configured to control the power unit to output the DC current output by the charging pile according to the second DC charging information to the power battery.

22. The power conversion device according to claim 12, wherein: The control unit is used to receive the status parameters of the power battery sent by the battery management system of the power battery.

23. A power conversion device, characterized in that: The device comprises a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call the computer program to execute the charging method according to any one of claims 1 to 11.

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