Charging system and charging method

Abstract

Provided in the embodiments of the present application are a charging system and a charging method. The charging system comprises a plurality of charging devices, a plurality of energy storage devices and at least one switch module, wherein each charging device comprises an alternating-current to direct-current (AC-DC) conversion apparatus, a DC bus and a DC-DC conversion apparatus, the AC-DC conversion apparatus being used for converting an AC into a DC and outputting the DC into the DC bus, and the DC-DC conversion apparatus being used for acquiring the DC from the DC bus, performing power conversion, and then outputting the DC to a load; and each energy storage device is connected to the DC bus of each charging device by means of at least one switch module, such that power transmission is performed between each energy storage device and the DC bus of each charging device. In the embodiments of the present application, each energy storage device in the charging system can flexibly distribute power to a plurality of charging devices, thereby increasing the utilization rate of energy storage resources in the charging system.

Description

Charging system and charging method

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on December 27, 2023, with application number 202311827496.5, and priority to the Chinese patent application with the invention name “Charging System and Charging Method”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of charging, and more particularly, to a charging system and a charging method. Background Art

[0003] Charging stations, as essential service facilities for electric vehicles, provide the electricity they need to operate. The charging equipment in these stations draws power from the grid to charge electric vehicles. As electric vehicles become increasingly popular, the demand for power from the grid for charging equipment is increasing, placing increasing pressure on the grid.

[0004] To alleviate pressure on the power grid, some charging stations are adding energy storage devices. These devices provide power to charging equipment, reducing the amount of grid power required. Furthermore, to meet the charging needs of more electric vehicles, charging stations require more charging equipment. However, in current practical applications, energy storage devices in charging stations cannot flexibly distribute power to multiple charging devices, resulting in low utilization of energy storage resources within the stations. Summary of the Invention

[0005] The present application provides a charging system and a charging method, which can enable each energy storage device in the charging system to flexibly distribute power to multiple charging devices, thereby improving the utilization rate of energy storage resources in the charging system.

[0006] In a first aspect, a charging system is provided, which includes: multiple charging devices, multiple energy storage devices and at least one switch module; each of the charging devices includes an AC-DC converter, a DC bus and a DC-DC converter, the AC-DC converter is used to convert AC power into DC power and output it to the DC bus, and the DC-DC converter is used to obtain DC power from the DC bus, and output the DC power to a load after power conversion; each of the energy storage devices is connected to the DC bus of each of the charging devices through the at least one switch module; the at least one switch module is used to disconnect or connect the connection between each of the energy storage devices and the DC bus of each of the charging devices, so as to enable power transmission between each of the energy storage devices and the DC bus of each of the charging devices.

[0007] In the above technical solution, by connecting multiple energy storage devices in the charging system to the DC bus of each charging device through at least one switch module, any energy storage device in the charging system can transmit power to the DC bus of any charging device. Furthermore, in actual application, each energy storage device in the charging system can flexibly allocate power to multiple charging devices in the charging system, so that the power of each energy storage device can be shared among multiple charging devices. This can not only increase the output power of each charging device in the charging system to meet the charging power requirements of different loads, but also improve the utilization rate of energy storage resources in the charging system and the balance of SOC between each energy storage device.

[0008] In combination with the first aspect, in certain implementations of the first aspect, at least one switch module includes at least one first switch module and multiple second switch modules, each energy storage device is connected to one end of each second switch module through the same first switch module, and the other ends of the multiple second switch modules are connected one-to-one to the DC bus of multiple charging devices; or, each energy storage device is connected to one end of each first switch module in the multiple first switch modules, the other ends of the multiple first switch modules are connected one-to-one to one end of the multiple second switch modules, and the other ends of the multiple second switch modules are connected one-to-one to the DC bus of the multiple charging devices.

[0009] In the above technical solution, the multiple switch modules in the charging system are configured as two-stage switch modules, including at least one first switch module and multiple second switch modules. The first switch module controls whether each energy storage device is connected to the charging system to enable power transmission with the DC bus of a designated charging device, while the second switch module controls the energy storage device connected to the charging system to transmit power to the DC bus of the designated charging device. This enables power transmission between any energy storage device in the charging system and the DC bus of any charging device, thereby facilitating flexible power distribution from each energy storage device in the charging system to multiple charging devices.

[0010] In addition, since the multiple second switch modules are connected one-to-one with the DC busbars of the multiple charging devices, the multiple second switch modules can be respectively set in the corresponding connected charging devices, which is conducive to making the connection between each second switch module and the DC busbar of the corresponding charging device more in line with the safety requirements of the corresponding charging device, thereby improving the overall safety of the charging system.

[0011] In combination with the first aspect, in certain implementations of the first aspect, when a charging device charges a load, in response to the output power of a charging device being less than the charging power requirement of the load, at least one first switch module is used to conduct the connection between multiple energy storage devices and a second switch module corresponding to the DC bus of a charging device, and the second switch module corresponding to the DC bus of a charging device is used to conduct the connection between the energy storage device conducted through at least one first switch module and the DC bus of a charging device.

[0012] In the above technical solution, when the output power of any charging device in the charging system does not meet the charging power requirement of the load, the first switch module and the second switch module are used to conduct the connection between multiple energy storage devices in the charging system and the DC bus of any charging device, so that the multiple energy storage devices can transmit power to the DC bus of any charging device, thereby increasing the output power of any charging device, which is conducive to meeting the charging power requirement of the load.

[0013] In combination with the first aspect, in certain implementations of the first aspect, at least one first switch module is used to conduct the connection between multiple energy storage devices and a second switch module corresponding to the DC bus of a charging device, including: in response to a difference between the state of charge (SOC) of the two energy storage devices being greater than a preset SOC difference, at least one first switch module is used to conduct the connection between the energy storage device with the largest SOC among the two energy storage devices and the second switch module corresponding to the DC bus of a charging device; or, in response to a difference between the state of charge (SOC) of the two energy storage devices being less than or equal to the preset SOC difference, at least one first switch module is used to conduct the connection between each of the two energy storage devices and the second switch module corresponding to the DC bus of a charging device.

[0014] It is understood that if the difference between the SOCs of the two energy storage devices is greater than the preset SOC difference, it can mean that the difference in the remaining charge of the two energy storage devices is large. If the difference between the SOCs of the two energy storage devices is less than or equal to the preset SOC difference, it can mean that the remaining charge of the two energy storage devices is equal or has a small difference.

[0015] In the above technical solution, when the remaining charge of two energy storage devices in the charging system differs significantly, the first and second switch modules are used to connect the energy storage device with the highest SOC of the two energy storage devices to the DC bus of the charging device, allowing the energy storage device with the higher remaining charge to transmit power to the charging device first. This not only increases the output power of the charging device to meet the charging power demand of the load, but also reduces the difference in remaining charge between the two energy storage devices, thereby improving the SOC balance between the two energy storage devices.

[0016] Furthermore, when the difference in remaining charge between the two energy storage devices in the charging system is small, the first and second switch modules are used to connect each of the two energy storage devices to the DC bus of the charging device, allowing both energy storage devices to transmit power to the charging device. This not only increases the output power of the charging device to meet the charging power demand of the load, but also ensures that the remaining charge of the two energy storage devices remains equal or has a small difference, thereby improving the SOC balance between the two energy storage devices.

[0017] In combination with the first aspect, in certain implementations of the first aspect, when a charging device and another charging device respectively charge a load, in response to the output power of one charging device and the output power of the other charging device being less than the charging demand power of the load, at least one first switch module is used to connect a part of the multiple energy storage devices to the second switch module corresponding to the DC bus of one charging device, and to connect another part of the energy storage devices to the second switch module corresponding to the DC bus of another charging device.

[0018] In the above technical solution, when any two charging devices in the charging system are charging a load separately, the first switch module is used to connect a portion of the multiple energy storage devices to the DC bus of one of the charging devices, and another portion of the energy storage devices to the DC bus of another charging device, so that any one of the multiple energy storage devices transmits power only to the DC bus of one charging device. This not only increases the output power of the two charging devices to meet the charging power requirements of the load, but also avoids the problem of circulating current in the charging system caused by the same energy storage device in the multiple energy storage devices simultaneously transmitting power to the DC buses of the two charging devices, thereby improving the overall operational safety of the charging system.

[0019] In combination with the first aspect, in certain implementations of the first aspect, when the difference between the output power of one charging device and the charging power requirement of the load is greater than the difference between the output power of another charging device and the charging power requirement of the load, the average SOC of one part of the energy storage devices is greater than the average SOC of another part of the energy storage devices.

[0020] It can be understood that when the difference between the output power of one charging device and the charging power requirement of the load is greater than the difference between the output power of another charging device and the charging power requirement of the load, in order to meet the charging power requirement, the output power required by the one charging device is greater than the output power required by the other charging device.

[0021] In the above technical solution, when the output power required by one charging device is greater than the output power required by another charging device in order to meet the charging power demand of the load, by selecting a portion of the multiple energy storage devices in the charging system with relatively more remaining power to transmit power to the DC bus of the one charging device, and selecting another portion of the energy storage devices with relatively less remaining power to transmit power to the DC bus of the other charging device, it is beneficial to ensure that the output power of both charging devices meets the charging power demand of the load, and it is also beneficial to improve the balance between the SOCs of the multiple energy storage devices.

[0022] In a second aspect, a charging method is provided, which includes: when a charging device in a charging system charges a load, obtaining the charging power requirement of the load; in response to the output power of a charging device being less than the charging power requirement of the load, controlling at least one switch module in the charging system to connect multiple energy storage devices in the charging system with a DC bus of a charging device, wherein the DC bus of a charging device is used to collect the DC power output by an AC-DC converter in a charging device, and output the collected DC power to the load through a DC-DC converter.

[0023] In the above technical solution, multiple energy storage devices in the charging system are connected to the DC bus of any charging device in the charging system through at least one switch module. When the output power of any charging device does not meet the charging power requirement of the load, the connection between the multiple energy storage devices and the DC bus of any charging device can be connected by controlling at least one switch module, so that the power of the multiple energy storage devices can be shared with the DC bus of any charging device, thereby increasing the output power of any charging device, which is conducive to meeting the charging power requirement of the load.

[0024] In combination with the second aspect, in certain implementations of the second aspect, controlling at least one switch module in a charging system to conduct the connection between multiple energy storage devices and the DC bus of a charging device includes: controlling at least one first switch module to conduct the connection between multiple energy storage devices and the second switch module corresponding to the DC bus of a charging device, and controlling the second switch module corresponding to the DC bus of a charging device to conduct the connection between the energy storage device conducted through at least one first switch module and the DC bus of a charging device, wherein the at least one first switch module and the second switch module corresponding to the DC bus of a charging device belong to at least one switch module.

[0025] In combination with the second aspect, in certain implementations of the second aspect, controlling at least one first switch module to conduct the connection between multiple energy storage devices and a second switch module corresponding to the DC bus of a charging device includes: in response to a difference between the state of charge (SOC) of two energy storage devices among the multiple energy storage devices being greater than a preset SOC difference, controlling at least one first switch module to conduct the connection between the energy storage device with the largest SOC among the two energy storage devices and the second switch module corresponding to the DC bus of a charging device; or, in response to a difference between the state of charge (SOC) of the two energy storage devices being less than or equal to the preset SOC difference, controlling at least one first switch module to conduct the connection between each of the two energy storage devices and the second switch module corresponding to the DC bus of a charging device.

[0026] In combination with the second aspect, in certain implementations of the second aspect, the charging method further includes: when a charging device and another charging device in the charging system respectively charge a load, in response to the output power of one charging device and the output power of the other charging device being less than the output power of the load, controlling at least one first switch module to connect a part of the multiple energy storage devices with the second switch module corresponding to the DC bus of one charging device, and connecting another part of the energy storage devices with the second switch module corresponding to the DC bus of another charging device.

[0027] In combination with the second aspect, in certain implementations of the second aspect, when the difference between the output power of one charging device and the charging power requirement of the load is greater than the difference between the output power of another charging device and the charging power requirement of the load, the average SOC of one part of the energy storage devices is greater than the average SOC of another part of the energy storage devices.

[0028] For the beneficial effects of the second aspect that are not detailed, please refer to the beneficial effects of the first aspect mentioned above, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG1 is a schematic structural diagram of a charging system provided in an embodiment of the present application.

[0030] FIG2 is a schematic diagram of the connection structure of the charging system shown in FIG1 .

[0031] 3 to 8 are schematic structural diagrams of a charging system provided in an embodiment of the present application.

[0032] 9 to 10 are schematic flow charts of a charging method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0033] To facilitate understanding of the embodiments of the present application, the following points are explained before introducing the embodiments of the present application.

[0034] In the description of the embodiments of this application, "connection" may refer to an electrical connection, which can be understood as the transmission of signals between two electrical components through direct or indirect electrical connection. For example, when A and B are connected, it can be understood that A and B are directly electrically connected, or it can be understood that A and B are indirectly electrically connected through one or more other electrical components.

[0035] In the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may include one or more features, either explicitly or implicitly. In addition, in the description of the embodiments of the present application, "plurality" means two or more than two, and "at least one" and "one or more" mean one, two, or more than two.

[0036] In the description of the embodiments of the present application, unless otherwise specified, "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0037] The following is a brief introduction to the technical terms involved in the embodiments of the present application to facilitate subsequent understanding of the embodiments of the present application.

[0038] State of charge (SOC): This indicator reflects the remaining capacity of an energy storage device. It is the ratio of the remaining capacity to the rated capacity, often expressed as a percentage. An SOC of 0 indicates zero remaining capacity, while an SOC of 100% indicates a fully charged energy storage device.

[0039] Peak electricity prices and valley electricity prices: These refer to an electricity pricing system that charges electricity based on peak and valley electricity usage. Peak electricity usage generally refers to electricity supply when electricity consumption is concentrated and the power supply is tight, such as during daytime. The time period of peak electricity usage can be called the peak period, and the electricity price during peak electricity usage can be called the peak electricity price. Valley electricity usage generally refers to electricity consumption when electricity consumption is relatively low and the power supply is relatively high, such as during nighttime. The time period of valley electricity usage can be called the valley period, and the electricity price during valley electricity usage can be called the valley price. The other electricity usage periods besides peak and valley electricity usage are called normal periods, or normal periods, and the electricity price during normal periods is called the flat price. Peak electricity prices generally have the highest charging standards, followed by flat prices, and valley prices have the lowest charging standards.

[0040] The technical solution in this application will be described below with reference to the accompanying drawings.

[0041] First, to facilitate understanding of the technical solutions provided by the embodiments of the present application, the following first introduces the application scenarios to which the embodiments of the present application are applicable.

[0042] FIG1 exemplarily shows a structural diagram of a charging system 100 provided in an embodiment of the present application.

[0043] Referring to Figures (a) and (b) in Figure 1 , the charging system 100 may include a charging device 110 and an electric vehicle 120. The charging device 110 may receive AC power from an external power grid 20, convert the AC power into stable DC power, and transmit the DC power to the electric vehicle 120 to charge the electric vehicle 120. Alternatively, the electric vehicle 120 may also output power back to the external power grid 200 via the charging device 110.

[0044] It can be understood that in the embodiment of the present application, the alternating current output by the external power grid 20 can be referred to as mains power.

[0045] In some embodiments, as shown in FIG1(a), a charging device 110 may include a charging host 111, at least one charging terminal 112, and at least one charging gun 113. The charging host 111 is connected to at least one charging terminal 112, which in turn is connected to at least one charging gun 113. Each charging gun 113 is configured to connect to an electric vehicle 120. In a specific implementation, one charging terminal 112 may be connected to one or more charging guns 113.

[0046] The charging host 111 may include multiple power conversion devices that can convert AC power from the external power grid 20 into stable DC power and transmit it to the charging terminal 112. The charging terminal 112 can transmit this stable DC power to the electric vehicle 120 via the connected charging gun 113 to charge the electric vehicle 120.

[0047] The charging terminal 112 may include a housing, a human-computer interaction interface, a charging control unit, a metering and billing unit, etc., and is used to perform information exchange, energy transmission, metering and billing, etc. with the electric vehicle 120.

[0048] The electric vehicle 120 is a vehicle that is powered by electricity. It can be a pure electric vehicle (pure EV / battery EV), a hybrid electric vehicle (HEV), a range-extended electric vehicle (REEV), or a plug-in hybrid electric vehicle (PHEV).

[0049] In other embodiments, as shown in (b) of FIG. (1), the charging device 110 may be an integrated charging pile. Specifically, the charging device 110 may directly set the human-machine interface, charging control unit, metering and billing unit, etc. in the charging host 111, so that the charging device 110 may only include the charging host 111 and at least one charging gun 113 connected to the charging host 111, but not the charging terminal 112. The multiple power conversion devices in the charging host 111 may convert the AC power from the external power grid 20 into stable DC power, and then directly transmit it to the electric vehicle 120 through the charging gun 113.

[0050] FIG2 exemplarily shows a schematic diagram of the connection structure of the charging system 100 shown in FIG1( a ).

[0051] Referring to Figure 2 , the charging host 111 includes multiple AC-DC converters 1111, multiple DC-DC converters 1112, a DC bus 1113, and a power distribution device 1114. The multiple AC-DC converters 1111 are connected in parallel between the external power grid 20 and the DC bus 1113. The inputs of the multiple DC-DC converters 1112 are connected to the DC bus 1113, and the outputs of the multiple DC-DC converters 1112 are connected to the input of the power distribution device 1114. The output of the power distribution device 1114 is connected to the charging gun 113 via the charging terminal 112.

[0052] The multiple AC-DC converters 1111 are configured to receive alternating current (AC) from the external power grid 20, convert the AC power into direct current (DC), and output the DC power to the DC bus 1113. Specifically, the DC bus 1113 is configured to aggregate the DC power output by the multiple AC-DC converters 1111. In a specific implementation, the inputs of the multiple AC-DC converters 1111 can be connected to the external power grid 20 via a transformer 30. The transformer 30 is configured to step down the high-voltage AC power from the external power grid 20 and output the resulting low-voltage AC power to the multiple AC-DC converters 1111. For example, the transformer 30 can step down 10 kV AC power from the external power grid 20 to 380 V AC power, which is then output to the multiple AC-DC converters 1111.

[0053] The plurality of DC-DC conversion devices 1112 are used to obtain direct current (DC) from the DC bus 1113 , and further convert the obtained DC into DC power suitable for the electric vehicle 120 before transmitting the converted DC power to the power distribution device 1114 .

[0054] The power distribution device 1114 is used to dynamically distribute the direct current output by multiple DC-DC conversion devices 1112 according to the actual charging power required by the electric vehicle 120, and transmit the distributed charging power to the electric vehicle 120 through the charging gun 113 connected to the charging terminal 112 to charge the electric vehicle 120.

[0055] As described in the background technology section above, to alleviate the load on the external power grid 20, energy storage devices have been added to the charging system 100. These devices provide power to the charging device 110, thereby reducing the amount of power drawn from the external power grid 200 by the charging device 110. At the same time, to meet the charging needs of more electric vehicles 120, the number of charging devices 110 deployed in the charging system 100 has also increased.

[0056] However, in current practical applications, each energy storage device in the charging system 100 is often directly connected to the DC bus 1113 of the fixed charging device 110. This results in each energy storage device in the charging system 100 being able to share power only with the connected charging device 110 and unable to share power with other unconnected charging devices 110, resulting in low utilization of the energy storage resources in the charging system 100.

[0057] In addition, the randomness of charging vehicles and the different charging power requirements of different electric vehicles 120 can easily cause uneven charging loads on different charging devices 110 in the charging system 100. Accordingly, the power usage of the energy storage devices connected to different charging devices 110 varies greatly, resulting in poor SOC balance between the energy storage devices in the charging system 100. For example, the SOC of the energy storage device connected to one charging device 110 is 20%, while the SOC of the energy storage device connected to another charging device 110 is 70%. If the energy storage devices in the charging system 100 are in a state of SOC imbalance for a long time, there is a high risk of a short service life of the energy storage devices and low utilization of the energy storage resources in the charging system 100.

[0058] Based on the above, embodiments of the present application provide a charging system and a charging method, which enable each energy storage device in the charging system to flexibly allocate power to multiple charging devices, thereby improving the utilization rate of energy storage resources in the charging system.

[0059] The following is a detailed description of the charging system and charging method provided in the embodiments of the present application, respectively, with reference to the accompanying drawings. It should be noted that, for ease of understanding, in the drawings provided in the embodiments of the present application, the power transmission line is represented by a real line, and the signal transmission line is represented by a dotted line.

[0060] FIG3 is a schematic structural diagram of a charging system provided in an embodiment of the present application.

[0061] 3 , a charging system 300 may include a plurality of charging devices 310 , a plurality of energy storage devices 320 , and at least one switch module 330 .

[0062] Each charging device 310 includes multiple AC-DC converters 311, multiple DC-DC converters 312, and a DC bus 313. The multiple AC-DC converters 311 are used to receive AC power from an external power grid, such as from an external power grid 20 via the transformer 30 shown in FIG2 , and convert the AC power into DC power before outputting it to the DC bus 313. In other words, the DC bus 313 can aggregate the DC power output by the multiple AC-DC converters 311. The multiple DC-DC converters 312 are used to obtain DC power from the DC bus 313, perform power conversion on the obtained DC power, and output it to the load 40.

[0063] It is understood that the charging device 310 can be a split-type charging pile or an integrated charging pile as shown in Figure 1 above. For a detailed description of the charging device 310, please refer to the relevant description of the embodiments shown in Figures 1 and 2 above, and will not be repeated here. It should be noted that for ease of description and understanding, the embodiment of this application is described using the split-type charging pile shown in Figure 1 (a) as an example in which the charging device 310 is used.

[0064] It is also understood that in the embodiments of the present application, the load 40 may be the electric vehicle 120 shown in FIG. 1 , or other equipment that uses a DC power supply as a power supply, such as industrial vehicles, agricultural vehicles, airplanes, and trains. For ease of description and understanding, the embodiments of the present application are described using the electric vehicle 120 shown in FIG. 1 as an example of the load 40.

[0065] Continuing with FIG3 , each energy storage device 320 is connected to the DC bus 313 of each charging device 310 via at least one switch module 330. The at least one switch module 330 is configured to disconnect or connect the connection between each energy storage device 320 and the DC bus 313 of each charging device 310, thereby enabling power transfer between each energy storage device 320 and the DC bus 313 of each charging device 310.

[0066] It will be understood that in the embodiments of the present application, the specific implementation of the energy storage device 320 can be any method that can achieve the functions of storing and outputting electrical energy. That is, the energy storage device 320 can be charged or discharged. For example, the energy storage device 320 can be an energy storage battery pack, which can include multiple battery packs connected in series and / or in parallel. It should be noted that when the energy storage device 320 is an energy storage battery pack, the SOC of the energy storage device 320 can be the average SOC of the multiple battery packs included in the energy storage battery pack.

[0067] In specific implementations, in some embodiments, the energy storage device 320 may further include a DC-DC converter. The DC-DC converter may be configured to convert the DC power output by the multiple battery packs and transmit the converted DC power to the DC bus 313 of the charging device 310 via at least one switch module 330. This ensures that the voltage of the DC power input to the DC bus 313 is equal to the voltage of the DC bus 313 itself, thereby ensuring normal power transmission from the energy storage device 320 to the DC bus 313 of the charging device 310.

[0068] Furthermore, the DC-DC converter can also be used to convert the DC power transmitted by the DC bus 313 of the charging device 310 through at least one switching module 330, and transmit the converted DC power to the multiple battery packs, so that the voltage of the DC power transmitted to the multiple battery packs meets the charging power requirements of the multiple battery packs. In other words, the DC-DC converter can be a bidirectional DC-DC converter.

[0069] It is also understood that in the embodiment of the present application, the number of charging devices 310 and energy storage devices 320 can be the same or different. For ease of description and understanding, the embodiment of the present application is described as an example in which the number of charging devices 310 and energy storage devices 320 is the same.

[0070] In an embodiment of the present application, multiple energy storage devices 320 in the charging system 300 are connected to the DC bus 313 of each charging device 310 in the charging system 300 through at least one switch module 330, so that power can be transmitted between any energy storage device 320 in the charging system 300 and the DC bus 313 of any charging device 310.

[0071] For example, when any charging device 310 in the charging system 300 charges the load 40, if the output power of any charging device 310 is less than the charging power requirement of the load 40, each energy storage device 320 in the charging system 300 can transmit power to the DC bus 313 of any charging device 310 through at least one switch module 330, thereby increasing the output power of any charging device 310 to meet the charging power requirement of the load 40.

[0072] It is understood that the output power of any charging device 310 may refer to the real-time output power of any charging device 310, or may refer to the maximum output power of any charging device 310. For ease of description and understanding, the present embodiment is described using the example where the output power of any charging device 310 refers to the real-time output power of any charging device 310.

[0073] It is also understandable that when the SOCs of the energy storage devices 320 in the charging system 300 differ significantly, continuing to utilize the energy storage device 320 with the lower SOC, i.e., continuing to utilize the energy storage device 320 with the lower remaining charge to transmit power to the DC bus 313 of any charging device 310, will not only increase the SOC imbalance between the energy storage devices 320, but also prevent the energy stored in the energy storage device 320 with the higher remaining charge from being fully utilized, resulting in a low utilization rate of the energy storage resources in the charging system 300. Furthermore, this may cause the energy storage device 320 with the lower charge to run low on power during the process of transmitting power to the DC bus 313 of any charging device 310, thereby affecting the service life of the energy storage device 320.

[0074] Therefore, in a specific implementation, based on the SOC of each energy storage device 320 in the charging system 300, at least one switch module 330 can prioritize connecting the energy storage device 320 with a higher SOC to the DC bus 313 of any charging device 310, allowing the energy storage device 320 with a higher remaining charge to preferentially transmit power to the DC bus 313 of any charging device 310. This can improve the SOC balance between the energy storage devices 320 in the charging system 300, extend the service life of each energy storage device 320, and increase the utilization rate of energy storage resources in the charging system 300.

[0075] For another example, when the grid price is relatively low at off-peak prices, the charging device 310 in the charging system 300 can receive AC power from the grid, convert the AC power, and then transmit it to each energy storage device 320 via at least one switch module 330, so that the energy storage device 320 can store as much electrical energy as possible. This can also be called charging the energy storage device 320. Thus, when any charging device 310 in the charging system 300 charges the load 40 when the grid price is at peak prices, the energy storage device 320 can be preferentially used to transmit power to the DC bus 313 of any charging device 310 via at least one switch module 330, thereby reducing the amount of AC power received by any charging device 310 from the grid at peak prices, thereby reducing the cost of charging the load 40 and alleviating pressure on the grid. In other words, the energy storage device 320 is used to achieve peak load shifting.

[0076] It is understandable that when the SOCs of the energy storage devices 320 in the charging system 300 differ significantly, if power is continuously transmitted to the energy storage device 320 with a higher SOC through the DC bus 313 of the charging device 310, that is, if the energy storage device 320 with a higher remaining power is continuously charged, this will also increase the imbalance of the SOCs between the energy storage devices 320, and may also cause the energy storage device 320 with less power to be insufficiently charged during the process of transmitting power to the DC bus 313 of the charging device 310, thereby affecting the service life of the energy storage device 320.

[0077] Therefore, in a specific implementation, based on the SOC of each energy storage device 320 in the charging system 300, at least one switch module 330 can prioritize connecting the energy storage device 320 with a lower SOC to the DC bus 313 of the charging device 310, so that the charging device 310 preferentially charges the energy storage device 320 with the lower remaining charge. This helps improve the SOC balance among the energy storage devices 320 in the charging system 300.

[0078] In the above technical solution, each energy storage device 320 in the charging system 300 can be connected to the DC bus 313 of each charging device 310 in the charging system 300 via at least one switch module 330. Furthermore, each energy storage device 320 in the charging system 300 can flexibly allocate power to the multiple charging devices 310 in the charging system 300 based on actual demand, enabling each energy storage device 310 to achieve power sharing among the multiple charging devices 310. This not only improves the utilization rate of the energy storage resources in the charging system 300, but also increases the output power of each charging device 310 in the charging system 300 to meet the charging power requirements of different loads.

[0079] For example, when the charging system 300 is applied to a fully liquid-cooled supercharging station, the DC bus 313 of any charging device 310 in the charging system 300 can receive power transmitted from multiple energy storage devices 320 in the charging system 300 through at least one switch module 330 to increase the power output of any charging device 300 to the electric vehicle, thereby helping to meet the demand for high-power supercharging of electric vehicles. For example, a high-power supercharging of 400kW can be performed on electric vehicles. This is conducive to achieving a charging speed of one kilometer per second, that is, it is conducive to charging an electric vehicle with enough energy to travel one kilometer in one second, and providing users with a charging experience of "a cup of coffee, a full charge".

[0080] It is understood that when the charging system 300 is used in a fully liquid-cooled supercharging station, the charging host, charging terminal, and charging gun in each charging device 310 in the charging system 300 are all liquid-cooled for heat dissipation, and the maximum output power of each charging gun of each charging device 310 is greater than or equal to a preset power threshold. The preset power threshold can be, for example, 250 kW.

[0081] Furthermore, if multiple energy storage devices 320 are directly connected to the DC bus 313 of different charging devices 310, for example, if the two energy storage devices 320 shown in FIG3 are directly connected to the DC bus 313 of two charging devices 310, and the DC bus 313 of the two charging devices 310 are connected, power sharing between the energy storage devices 320 and the two charging devices 310 can also be achieved. However, connecting the DC bus 313 of the two charging devices 310 can easily form a loop between the DC bus 313 of the two charging devices 310 and the transformer 30 connected to the upstream stage, generating a circulating current, thereby affecting the safety of the overall operation of the charging system 300.

[0082] In the embodiment of the present application, the energy storage devices 320 in the charging system 300 share power among multiple charging devices 310 via at least one switch module 330, eliminating the need to connect the DC busbars 313 of different charging devices 310. This helps avoid circulating currents in the charging system 300 caused by connecting the DC busbars 313 of different charging devices 310, thereby improving the overall operational safety of the charging system 300.

[0083] The following is an exemplary description of a specific implementation of connecting each energy storage device 320 mentioned above to the DC bus 313 of each charging device 310 via at least one switch module 330 .

[0084] FIG4 is a schematic structural diagram of a charging system 300 provided in an embodiment of the present application.

[0085] 4 , in some embodiments, a charging system 300 may include multiple charging devices 310, multiple energy storage devices 320, and a switch module 330. The switch module 330 may include multiple switches, with each energy storage device 320 connected to the DC bus 313 of a charging device 310 via a switch in the switch module 330.

[0086] For example, as shown in FIG4 , a charging system 300 includes two charging devices (i.e., charging device 310a and charging device 310b) and two energy storage devices 320 (i.e., including energy storage device 320a and energy storage device 320b). The charging system 300 includes a switch module 330, and the switch module 330 includes a switch S1, a switch S2, a switch S3, and a switch S4. The energy storage device 320a is connected to the DC bus 313 of the charging device 310a via switch S1, and is connected to the DC bus 313 of the charging device 310b via switch S3. The energy storage device 320b is connected to the DC bus 313 of the charging device 310a via switch S2, and is connected to the DC bus 313 of the charging device 310b via switch S4.

[0087] In one example, taking the energy storage device 320a and the energy storage device 320b transmitting power to the DC bus 313 of the charging device 310a as an example, the switch S1 and the switch S2 are closed so that the power output by the energy storage device 320a and the energy storage device 320b can be transmitted to the DC bus 313 of the charging device 310a through the switch S1 and the switch S2 respectively, thereby increasing the output power of the charging device 310a.

[0088] It is understandable that, in a specific implementation, the switch module 330 can be integrated into a separate box in the charging system 300, and connected to the DC bus 313 of the charging device 310a, the DC bus 313 of the charging device 310b, and the energy storage device 320a and the energy storage device 320b respectively through the box.

[0089] In the above technical solution, each energy storage device 320 in the charging system 300 can be connected to the DC bus 313 of each charging device 310 through a switch module 330. The overall connection structure of the charging system 300 is simple, which helps to reduce the design cost of the charging system 300.

[0090] FIG5 and FIG6 are schematic structural diagrams of another charging system 300 provided in an embodiment of the present application.

[0091] 5 and 6 , unlike the embodiment shown in FIG4 , in some embodiments, the charging system 300 may include multiple charging devices 310, multiple energy storage devices 320, and multiple switch modules 330. The multiple switch modules 330 include at least one first switch module 330a and multiple second switch modules 330b.

[0092] Each energy storage device 320 is connected to one end of each of the plurality of second switch modules 330b via the at least one switch module 330a. The other ends of the plurality of second switch modules 330b are connected one-to-one to the DC busbars 313 of the plurality of charging devices 310. The at least one first switch module 330a is used to disconnect or connect each energy storage device 320 with each second switch module 330b. Each second switch module 330b is used to disconnect or connect the energy storage device 320 connected via the first switch module 330a from the DC busbar 313 of the charging device 310a corresponding to each second switch module 330b.

[0093] It will be appreciated that in this embodiment of the present application, the multiple switch modules 330 are configured as a two-stage switch module, including a first switch module 330a and a second switch module 330b. The first switch module 330a controls whether each energy storage device 320 is connected to the charging system 300 to enable power transmission with the DC bus 313 of a designated charging device 310. The second switch module 330b controls power transmission between the energy storage device 320 connected to the charging system 300 and the DC bus 313 of the designated charging device 310. This enables power transmission between any energy storage device 320 in the charging system 300 and the DC bus 313 of any charging device 310.

[0094] In a specific implementation, in some embodiments, as shown in FIG5 , the multiple switch modules 330 in the charging system 300 may include a first switch module 330a and multiple second switch modules 330b. Each energy storage device 320 is connected to one end of each of the multiple second switch modules 330b via the same first switch module 330a, and the other ends of the multiple second switch modules 330b are connected to the DC busbars 313 of the multiple charging devices 310 in a one-to-one correspondence.

[0095] For example, as shown in FIG5 , continuing with the example of a charging system 300 including charging devices 310a and 310b, and energy storage devices 320a and 320b, the multiple switch modules 330 in the charging system 300 include a first switch module 330a and two second switch modules 330b (i.e., a second switch module 330b1 and a second switch module 330b2). The first switch module 330a includes a first switch S11, a first switch S12, a first switch S13, and a first switch S14; the second switch module 330b1 includes a second switch S21; and the second switch module 330b2 includes a second switch S22. The energy storage device 320a is connected to one end of the first switch S11, the energy storage device 320b is connected to one end of the first switch S13, the other end of the first switch S11 and the other end of the first switch S13 are connected in parallel to one end of the second switch S21, and the other end of the second switch S21 is connected to the DC bus of the charging device 310a.

[0096] Similarly, the energy storage device 320a is connected to one end of the first switch S12, the other end of the energy storage device 320b is connected to one end of the first switch S14, the other end of the first switch S12 and the other end of the first switch S14 are connected in parallel to one end of the second switch S22, and the other end of the second switch S22 is connected to the DC bus 313 of the charging device 310b.

[0097] In one example, using energy storage devices 320a and 320b transmitting power to the DC bus 313 of charging device 310a as an example, first switches S11 and S13 are closed, allowing energy storage devices 320a and 320b to be connected to the charging system 300 and to transmit power to the DC bus 313 of the designated charging device 310a. Furthermore, second switch S21 is closed, allowing energy storage devices 320a and 320b connected to the charging system 300 to transmit power to the DC bus 313 of charging device 310a. Consequently, the power output by charging device 320a can be transmitted to the DC bus 313 of charging device 310a via first switch S11 and second switch S21, and the power output by charging device 320b can be transmitted to the DC bus 313 of charging device 310b via first switch S13 and second switch S21, thereby increasing the output power of charging device 310a.

[0098] In a specific implementation, for example, the first switch module 330a can be integrated into a separate box in the charging system 300, the second switch module 330b1 can be set in the corresponding connected charging device 310a, and the second switch module 330b2 can be set in the corresponding connected charging device 310b, and are respectively connected to the first switch module 330a through a separate box in the charging system 300.

[0099] In the above technical solution, by configuring the multiple switch modules 330 in the charging system 300 as a first switch module 330a and multiple second switch modules 330b correspondingly connected to the DC bus 313 of multiple charging devices 310, power transmission can be achieved between any energy storage device 320 in the charging system 300 and the DC bus 313 of any charging device 310, thereby facilitating flexible power distribution from each energy storage device 320 in the charging system 300 to multiple charging devices 310. Furthermore, in practical applications, the multiple second switch modules 330b can be respectively installed in the corresponding charging devices 310, which helps ensure that the connection between each second switch module 330b and the DC bus 313 of the corresponding charging device 310 complies with the safety requirements of the corresponding charging device 310, thereby improving the overall safety of the charging system 300.

[0100] In other embodiments, as shown in FIG6 , unlike the embodiment shown in FIG5 , the multiple switch modules 330 in the charging system 300 may include multiple first switch modules 330a and multiple second switch modules 330b . Each energy storage device 320 is connected to one end of each of the multiple first switch modules 330a , the other ends of the multiple first switch modules 330a are connected in a one-to-one correspondence to one end of the multiple second switch modules 330b , and the other ends of the multiple second switch modules 330b are connected in a one-to-one correspondence to the DC busbars 313 of the multiple charging devices 310 . In other words, the number of the multiple first switch modules 330a, the number of the multiple second switch modules 330b, and the number of the multiple charging devices 310 in the charging system are equal.

[0101] For example, as shown in FIG6 , continuing with the example of a charging system 300 including charging devices 310a and 310b, and energy storage devices 320a and 320b, the multiple switch modules 330 in the charging system 300 include two first switch modules 330a (i.e., a first switch module 330a1 and a first switch module 330a2) and two second switch modules 330b (i.e., a second switch module 330b1 and a second switch module 330b2). The first switch module 330a1 includes a first switch S11 and a first switch S12, the first switch module 330a2 includes a first switch S13 and a first switch S14, the second switch module 330b1 includes a second switch S21, and the second switch module 330b2 includes a second switch S22. The energy storage device 320a is connected to one end of the first switch S11, the energy storage device 320b is connected to one end of the first switch S12, the other end of the first switch S11 and the other end of the first switch S12 are connected in parallel to one end of the second switch S21, and the other end of the second switch S21 is connected to the DC bus of the charging device 310a.

[0102] Similarly, the energy storage device 320a is connected to one end of the first switch S13, the other end of the energy storage device 320b is connected to one end of the first switch S14, the other end of the first switch S13 and the other end of the first switch S14 are connected in parallel to one end of the second switch S22, and the other end of the second switch S22 is connected to the DC bus 313 of the charging device 310b.

[0103] In one example, using the example of energy storage devices 320a and 320b transmitting power to the DC bus 313 of the charging device 310a, the first switch S11 and the first switch S12 are closed, allowing the energy storage devices 320a and 320b to be connected to the charging system 300 and to transmit power to the DC bus 313 of the designated charging device 310a. Furthermore, the second switch S21 is closed, allowing the energy storage devices 320a and 320b connected to the charging system 300 to transmit power to the DC bus 313 of the charging device 310a.

[0104] In a specific implementation, for example, since the number of the plurality of first switch modules 330a and the plurality of second switch modules 330b in the charging system 300 is the same, and the other ends of the plurality of first switch modules 330a are connected to one ends of the plurality of second switch modules 330b in a one-to-one correspondence, each first switch module 330a and the corresponding second switch module 330b can be disposed in a single housing. For example, each first switch module 330a and the corresponding second switch module 330b can be disposed in the charging device 310 to which the corresponding second switch module 330b is connected.

[0105] In the above technical solution, by configuring multiple switch modules 330 in the charging system 300 to be connected to corresponding first switch modules 330a and second switch modules 330b, and by correspondingly connecting the multiple switch modules 330a to the DC bus 313 of multiple charging devices 310a, power transmission can be achieved between any energy storage device 320 in the charging system 300 and the DC bus 313 of any charging device 310, thereby facilitating flexible power distribution from each energy storage device 320 in the charging system 300 to multiple charging devices 310. Furthermore, in practical applications, each first switch module 330a and the corresponding second switch module 330b can be installed in the corresponding charging device 310. In other words, the multiple switch modules 330 in the charging system 300 can be installed in the corresponding charging device 310. This facilitates ensuring that the connection between each switch module 330 and the DC bus 313 of the corresponding charging device 310 complies with the safety regulations of the corresponding charging device 310, thereby improving the overall safety of the charging system 300.

[0106] It is understandable that the specific structure of the multiple switch modules 330 in the charging system 300 introduced in the above embodiment is only an example. In the embodiment of the present application, it is sufficient as long as the multiple switch modules 330 can disconnect or connect the DC bus 313 of each energy storage device 320 and each charging device 310 in the charging system 300.

[0107] The above describes the various structures of the charging system 300 provided in the embodiment of the present application. The following describes the working process of the charging system 300 charging the load 40.

[0108] FIG7 is a schematic structural diagram of a charging system 300 provided in an embodiment of the present application.

[0109] Referring to FIG7 , a charging system 300 includes multiple charging devices 310, multiple energy storage devices 320, at least one first switch module 330a, and multiple second switch modules 330b. When a charging device 310 in the charging system 300 is charging a load 40, and the output power of the charging device 310 is less than the load's required charging power, the at least one first switch module 330a is configured to connect the multiple energy storage devices 320 to the corresponding second switch module 330b of the DC bus 313 of the charging device 310. The corresponding second switch module 330b is configured to connect the energy storage devices 320 connected via the at least one first switch module 330a to the DC bus 313 of the charging device 310. Consequently, the multiple energy storage devices 320 in the charging system 300 can transfer power to the DC bus 313 of the charging device 310, thereby increasing the output power of the charging device 310 and thereby meeting the required charging power of the load 40.

[0110] Specifically, as shown in Figure 7, taking the charging system 300 including the charging device 310a, the charging device 310b, the energy storage device 320a, the energy storage device 320b, the first switch module 330a1, the first switch module 330a2, and the second switch module 330b1, the second switch module 330b2 as an example, when the charging device 310a charges the load 40, in response to the output power of the charging device 310a being less than the charging power requirement of the load 40, the first switch S11 and the first switch S12 in the first switch module 330a1 are closed to connect the energy storage devices 320a and 320b with the second switch module 330b1, and the second switch S21 in the second switch module 330b1 is closed to connect the energy storage devices 320a, 320b and the DC bus 313 of the charging device 310a.

[0111] Thus, the energy storage device 320a and the energy storage device 320b can transmit power to the DC bus 313 of the charging device 310a through the first switch module 330a1 and the second switch module 330b1. The power transmission path can be shown as the bold arrow in FIG7 .

[0112] In a specific implementation, in some embodiments, the charging system 300 may further include a controller 340. The controller 340 may be connected to each charging device 310, each energy storage device 320, and each switch module 330 in the charging system 300, and may be used to control each charging device 310, each energy storage device 320, and each switch module 330. For example, the controller 340 may be used to control the first switch S11 and the first switch S12 in the first switch module 330a1 to close, so that the first switch module 330a1 connects the energy storage devices 320a and 320b with the second switch module 330b1.

[0113] It can be understood that in the embodiment of the present application, the controller 340 can serve as the main controller of the charging system 300 and be integrated into any charging device 310 in the charging system 300 .

[0114] Furthermore, in some embodiments, when a charging device 310 in the charging system 300 charges a load 40, in response to the output power of the charging device 310 being less than the charging power requirement of the load, at least one first switch module 330a is configured to connect the plurality of energy storage devices 320 to the second switch module 330b corresponding to the DC bus 313 of the charging device 310, which may specifically include:

[0115] In response to a difference between the SOCs of any two energy storage devices 320 among the multiple energy storage devices 320 being greater than a preset SOC difference, at least one first switch module 330a is configured to conduct a connection between the energy storage device 320 having the largest SOC among the any two energy storage devices 320 and the second switch module 330b corresponding to the DC bus 313 of the charging device 310; or

[0116] In response to the difference between the SOCs of any two energy storage devices 320 among the multiple energy storage devices 320 being less than or equal to a preset SOC difference, at least one first switch module 330a is used to conduct the connection between each energy storage device 320 among the any two energy storage devices 320 and the second switch module 330b corresponding to the DC bus 313 of the one charging device 310.

[0117] It is understood that if the SOC difference between any two energy storage devices 320 is greater than the preset SOC difference, it can mean that the remaining power of the two energy storage devices 320 differs significantly. If the SOC difference between any two energy storage devices 320 is less than or equal to the preset SOC difference, it can mean that the remaining power of the two energy storage devices 320 is equal or has a small difference. The preset SOC difference can be flexibly adjusted according to actual needs. For example, the preset SOC difference can be 5%, 8%, or 10%.

[0118] If the remaining charge between any two energy storage devices 320 differs significantly, at least one first switch module 330a connects the energy storage device 320 with the highest SOC among the two energy storage devices 320 to the DC bus 313 of the charging device 310. This allows the energy storage device 320 with the relatively higher remaining charge among the two energy storage devices 320 to preferentially transmit power to the DC bus 313 of the charging device 310. This not only increases the output power of the charging device 310 to meet the charging power requirement of the load 40, but also reduces the difference in remaining charge between the two energy storage devices 320, thereby facilitating improved SOC balance between the two energy storage devices 320.

[0119] If the remaining charges of any two energy storage devices 320 are equal or have a small difference, at least one first switch module 330a connects each of the two energy storage devices 320 to the DC bus 313 of the one charging device 310, allowing the two energy storage devices 320 to simultaneously transmit power to the DC bus 313 of the one charging device 310. This not only improves the output power of the one charging device 310 to meet the charging power requirement of the load 40, but also ensures that the remaining charges of the two energy storage devices 320 remain equal or have a small difference, thereby facilitating improved SOC balance between the two energy storage devices 320.

[0120] For example, referring to FIG7 , continuing with the example of charging device 310a supplying power to load 40, if the SOC of energy storage device 320a is 30% and the SOC of energy storage device 320b is 70%, the difference in remaining charge between energy storage devices 320a and 320b is significant. Closing first switch S12 in first switch module 330a1 and second switch S21 in second switch module 330b2 allows energy storage device 320b to preferentially transmit power to DC bus 313 of charging device 310a. This, in turn, helps reduce the difference in remaining charge between energy storage devices 320a and 320b, thereby improving the SOC balance between energy storage devices 320a and 320b.

[0121] Alternatively, when the SOC of energy storage device 320a is 68% and the SOC of energy storage device 320b is 70%, the difference in remaining charge between energy storage device 320a and energy storage device 320b is relatively small. Closing first switch S11 and first switch S12 in first switch module 330a1 and second switch S21 in second switch module 330b2 allows energy storage device 320a and energy storage device 320b to simultaneously transmit power to DC bus 313 of charging device 310a. This helps maintain a relatively small difference in remaining charge between energy storage device 320a and energy storage device 320b, thereby improving the SOC balance between energy storage device 320a and energy storage device 320b.

[0122] FIG8 is a schematic structural diagram of another charging system 300 provided in an embodiment of the present application.

[0123] Unlike the embodiment shown in FIG7 , in which one charging device 310 of the charging system 300 charges the load 40, in the embodiment shown in FIG8 , two charging devices 310 in the charging system 300 charge the load 40 separately. In response to the output power of both charging devices 310 being less than the required output power of the load 40, at least one switch module 330a is configured to connect a portion of the multiple energy storage devices 320 to the second switch module 330b corresponding to the DC bus 313 of one of the charging devices 310, and to connect another portion of the energy storage devices 320 to the second switch module 330b corresponding to the DC bus 313 of another of the charging devices 310.

[0124] Thus, one portion of the energy storage devices 320 transmits power to the DC bus 313 of one of the charging devices 310 via the corresponding second switch modules 330b, while the other portion of the energy storage devices 320 transmits power to the DC bus 313 of the other charging device 310 via the corresponding second switch modules 330b. In other words, any energy storage device 320 transmits power to the DC bus 313 of only one of the two charging devices 310.

[0125] Furthermore, in some embodiments, when the difference between the output power of one charging device 310 and the charging power required by the load 40 is greater than the difference between the output power of another charging device 310 and the charging power required by the load 40, the average SOC value of the aforementioned portion of the energy storage devices 320 is greater than the average SOC value of the aforementioned portion of the energy storage devices 320. That is, in a specific implementation, if the output power required by one charging device 310 is greater than the output power required by another charging device 310, a portion of the multiple energy storage devices 320 with relatively high remaining power is selected to transmit power to the DC bus 313 of one charging device 310, and a portion of the multiple energy storage devices 320 with relatively low remaining power is selected to transmit power to the DC bus 313 of the other charging device 310, so as to better enable the two charging devices 310 to meet the charging power requirements of different loads 40.

[0126] Specifically, referring to Figure 8, continuing to take the charging system 300 shown in Figure 6 as an example, which includes charging devices 310a and 310b, energy storage devices 320a and 320b, first switch modules 330a1 and 330a2, and second switch modules 330b1 and 330b2, when the charging device 310a charges the load 40a and the charging device 310b charges the load 40b, in response to the output power of the charging device 310a being less than the charging power requirement of the load 40a and the output power of the charging device 310b being less than the output power requirement of the load 40b, the first switch S11 in the first switch module 330a1 and the second switch S21 in the second switch module 330b1 are closed to connect the DC bus 313 between the energy storage device 320a and the charging device 310a. At the same time, the first switch S14 in the first switch module 330a2 and the second switch S22 in the second switch module 330b2 are closed to connect the energy storage device 320b and the DC bus 313 of the charging device 310b.

[0127] As a result, energy storage device 320a transmits power to DC bus 313 of charging device 310a via first switch module 330a1 and second switch module 330b1, while energy storage device 320b transmits power to DC bus 313 of charging device 310b via first switch module 330a2 and second switch module 330b2. This increases the output power of charging devices 310a and 310b, thereby facilitating the charging power requirements of loads 40a and 40b. The power transmission paths are shown as bold arrows in FIG8 .

[0128] It is understandable that if the energy storage device 320a (or energy storage device 320b) simultaneously transmits power to the DC bus 313 of the charging device 310a and the DC bus 313 of the charging device 310b, the loop formed between the energy storage device 320a, the DC bus 313 of the charging device 310a, the DC bus 313 of the charging device 310b and the transformer 30 connected to the front stage is prone to generate circulating current, thereby affecting the safety of the overall operation of the charging system 300.

[0129] In the embodiment of the present application, a first switch module 330a and a second switch module 330b are used to connect the energy storage device 320a to the DC bus 313 of the charging device 310a, and to connect the energy storage device 320b to the DC bus 313 of the charging device 310b. This allows the energy storage device 320a and the energy storage device 320b to simultaneously transmit power to the DC bus 313 of only one charging device 310. This not only increases the output power of the charging device 310 to meet the charging power requirements of the load 40, but also avoids the problem of circulating current in the charging system 300 caused by a single energy storage device 320 simultaneously transmitting power to the DC bus 313 of different charging devices 310, thereby improving the overall operational safety of the charging system 300.

[0130] It can also be understood that when the difference between the output power of charging device 310a and the charging power requirement of load 40a is greater than the difference between the output power of charging device 310b and the charging power requirement of load 40b, the SOC of energy storage device 320a is greater than the SOC of energy storage device 320b. In other words, to meet the charging power requirements of load 40a and load 40b, respectively, charging device 310a requires more output power than charging device 310b.

[0131] In this case, the energy storage device 320a with a relatively high remaining power is selected to transmit power to the DC bus 313 of the charging device 310a, and the energy storage device 320b with a relatively low remaining power is selected to transmit power to the DC bus 313 of the charging device 310b. This is beneficial for ensuring that the output power of the charging device 310a and the charging device 310b meet the charging power requirements of the load 40a and the load 40b respectively, and is also beneficial for improving the balance between the SOCs of the energy storage device 320a and the energy storage device 320b.

[0132] It should be noted that the embodiments shown in Figures 7 and 8 are described using the example of multiple energy storage devices 320 in the charging system 300 being able to discharge. In a specific implementation, when the SOC of the energy storage device 320 is greater than or equal to the preset SOC threshold, the remaining power of the energy storage device 320 is relatively large and can be discharged. When the SOC of the energy storage device 320 is less than the preset SOC threshold, the remaining power of the energy storage device 320 is relatively small and can only be charged, not discharged. The preset SOC threshold can be flexibly adjusted according to actual needs, for example, it can be 20% or 25%.

[0133] The structure of the charging system 300 provided in the embodiment of the present application is introduced above. The charging method provided in the embodiment of the present application and applicable to the charging system 300 is introduced below.

[0134] It should be understood that the description of the following method embodiment corresponds to the description of the above-mentioned structural embodiment. Therefore, for the contents not described in detail, reference can be made to the above-mentioned device embodiment and will not be repeated below.

[0135] 9 is a flow chart of a charging method 400 provided in an embodiment of the present application. The charging method 400 can be applied to the charging system 300 and can be specifically executed by a system controller in the charging system 300, such as the controller 340.

[0136] 9 , the charging method 400 may include:

[0137] S410: When a charging device in the charging system charges a load, the charging power requirement of the load is obtained.

[0138] Specifically, in combination with Figures 5 and 6, when a charging device 310 in the charging system 300 is connected to the load 40, the controller 340 can obtain the real-time output power of the charging device 310 and the charging power requirement of the load 40, thereby determining whether the real-time output power of the charging device 310 is less than the charging power requirement of the load 40.

[0139] For example, the controller 340 may be in communication with the one charging device 310 and the load 40 to receive information indicating real-time output power sent by the one charging device 310 and information indicating required charging power sent by the load 40 .

[0140] S420: In response to the output power of the one charging device being less than the charging power requirement of the load, controlling at least one switch module in the charging system to connect the DC bus of the one charging device to multiple energy storage devices in the charging system, so that the multiple energy storage devices transmit power to the DC bus of the one charging device, thereby increasing the output power of the one charging device and thereby facilitating meeting the charging power requirement of the load. The DC bus of the charging device is configured to aggregate the DC power output by the AC-DC converter in the one charging device and output the aggregated DC power to the load via the DC-DC converter.

[0141] In some embodiments, step S420 may specifically include:

[0142] In response to the output power of the charging device being less than the charging power requirement of the load, at least one first switch module is controlled to connect the plurality of energy storage devices to a second switch module corresponding to the DC bus of the charging device, and the second switch module corresponding to the DC bus of the charging device is controlled to connect the energy storage devices connected via the at least one first switch module to the DC bus of the charging device. The at least one first switch module and the second switch module corresponding to the DC bus of the charging device belong to at least one switch module.

[0143] The detailed description can be found in the above device embodiments, which will not be repeated here.

[0144] In the above technical solution, multiple energy storage devices in the charging system are connected to the DC bus of any charging device in the charging system through at least one switch module. When the output power of any charging device does not meet the charging power requirement of the load, the connection between the multiple energy storage devices and the DC bus of any charging device can be connected by controlling at least one switch module, so that the power of the multiple energy storage devices can be shared with the DC bus of any charging device, thereby increasing the output power of any charging device, which is conducive to meeting the charging power requirement of the load.

[0145] The charging method provided in the embodiment of the present application is further described in detail below with reference to FIG10 .

[0146] FIG10 is a flow chart of a charging method 500 provided in an embodiment of the present application. The charging method 500 can be applied to the charging system 300 described above, and can be specifically executed by a system controller in the charging system 300, such as the controller 340.

[0147] 10 , the charging method 500 may include:

[0148] S510: When a charging device in the charging system charges a load, the charging power requirement of the load is obtained.

[0149] For a detailed description of step S510, please refer to the relevant description of step S610 above, which will not be repeated here.

[0150] S520: Determine whether the output power of the charging device is less than the charging power required by the load.

[0151] In one possible case, if the output power of the charging device is greater than or equal to the required charging power of the load, it means that the real-time output power of the charging device meets the required charging power of the load, and S530' is executed.

[0152] S530': Control the charging device to charge the load.

[0153] It is understandable that, when the real-time output power of the one charging device meets the charging power requirement of the load, the one charging device can meet the demand for charging the load by only obtaining power from the power grid.

[0154] In another possible case, if the output power of the charging device is less than the charging power requirement of the load, it means that the real-time output power of the charging device does not meet the charging power requirement of the load, and S530 is executed at this time.

[0155] S530: Determine whether the SOCs of the multiple energy storage devices in the charging system are less than a preset SOC threshold.

[0156] 5 and 6 , the controller 340 may obtain information indicating its own SOC sent by each energy storage device 320 in the charging system 300 , thereby determining whether the SOC of each energy storage device 320 is less than a preset SOC threshold.

[0157] In one possible scenario, if the SOC of each energy storage device in the charging system is less than a preset SOC threshold, it means that the remaining power of each energy storage device in the charging system is low, and each energy storage device in the charging system can only be charged but not discharged. In this case, S530' is executed.

[0158] S530': Control the charging device to charge the load.

[0159] In another possible case, if the SOC of at least one energy storage device in the charging system is greater than or equal to a preset SOC threshold, it means that the remaining power of the at least one energy storage device is relatively large, and the at least one energy storage device can be discharged.

[0160] In one example, if the SOC of only one energy storage device in the charging system is greater than or equal to a preset SOC threshold, at least one switch module in the charging system is controlled to connect the DC bus of the energy storage device and the charging device, so that the energy storage device transmits power to the DC bus of the charging device to increase the output power of the charging device.

[0161] In another example, if the SOCs of the multiple energy storage devices in the charging system are all greater than or equal to the preset SOC threshold, it means that the multiple energy storage devices have a large amount of remaining power and the multiple energy storage devices can be discharged. In this case, S540 is executed.

[0162] S540 , determining whether a difference between the SOCs of any two energy storage devices among a plurality of energy storage devices whose SOCs are greater than or equal to a preset SOC threshold is greater than a preset SOC difference.

[0163] In one possible case, if the difference between the SOCs of the two energy storage devices is less than or equal to the preset SOC difference, it indicates that the difference in the remaining power of the two energy storage devices is small, and S550 ′ is executed.

[0164] S550', in response to the difference between the SOCs of the two energy storage devices being less than or equal to a preset SOC difference, controlling at least one switch module in the charging system to conduct a connection between each of the two energy storage devices and the DC bus of the one charging device, so that the two energy storage devices transmit power to the DC bus of the one charging device, thereby increasing the output power of the one charging device.

[0165] In some embodiments, S550′ may specifically include:

[0166] In response to a difference between the SOCs of the two energy storage devices being less than or equal to a preset SOC difference, at least one first switch module in the charging system is controlled to conduct the connection between each of the two energy storage devices and the second switch module corresponding to the DC bus of the one charging device, and the second switch module corresponding to the DC bus of the one charging device is used to conduct the connection between the two energy storage devices conducted through the at least one first switch module and the DC bus of the one charging device.

[0167] For detailed description, please refer to the above device embodiment, which will not be repeated here.

[0168] In the above technical solution, when the difference in the remaining power of the two energy storage devices is small, the first switch module and the second switch module are controlled to conduct the connection between each of the two energy storage devices and the DC bus of the one charging device, so that the two energy storage devices both transmit power to the DC bus of the one charging device, which is beneficial to improving the balance of the SOC between the two energy storage devices.

[0169] In another possible case, if the difference between the SOCs of the two energy storage devices is greater than the preset SOC difference, it means that the difference in the remaining power of the two energy storage devices is relatively large, and S550 is executed at this time.

[0170] S550, in response to the difference between the SOCs of the two energy storage devices being greater than a preset SOC difference, controlling at least one switch module in the charging system to conduct the connection between the energy storage device with the largest SOC among the two energy storage devices and the DC bus of the one charging device, so that the energy storage device with the largest SOC among the two energy storage devices transmits power to the DC bus of the one charging device, thereby increasing the output power of the one charging device.

[0171] In some embodiments, S550 may specifically include:

[0172] In response to a difference in the SOCs of the two energy storage devices being greater than a preset SOC difference, at least one first switch module in the charging system is controlled to conduct the connection between the energy storage device with the largest SOC among the two energy storage devices and the second switch module corresponding to the DC bus of the one charging device, and the second switch module corresponding to the DC bus of the one charging device is used to conduct the connection between the energy storage device with the largest SOC conducted through the at least one first switch module and the DC bus of the one charging device.

[0173] For detailed description, please refer to the above device embodiment, which will not be repeated here.

[0174] In the above technical solution, when the difference in the remaining power of the two energy storage devices is small, the first switch module and the second switch module are controlled to conduct the connection between the energy storage device with the largest SOC of the two energy storage devices and the DC bus of the one charging device, so that the energy storage device with the largest SOC of the two energy storage devices preferentially transmits power to the DC bus of the one charging device, which is conducive to improving the balance of the SOC between the two energy storage devices.

[0175] In some embodiments, method 500 may further include:

[0176] When a charging device and another charging device of the charging system respectively charge a load, in response to the output power of the one charging device and the output power of the other charging device being less than the output power of the load, at least one first switch module in the charging system is controlled to connect a part of the multiple energy storage devices with the second switch module corresponding to the DC bus of the one charging device, and to connect another part of the energy storage devices with the second switch module corresponding to the DC bus of the other charging device.

[0177] It can be understood that the SOC of each of the multiple energy storage devices is greater than or equal to a preset SOC threshold, that is, the multiple energy storage devices can all be discharged.

[0178] As a result, some of the multiple energy storage devices transmit power to the DC bus of one charging device, and another part of the energy storage devices transmit power to the DC bus of another charging device. This can not only increase the output power of the above-mentioned two charging devices, thereby helping to meet the charging power requirements of the load, but also help avoid the problem of circulating current in the charging system caused by one energy storage device simultaneously transmitting power to the DC buses of different charging devices in the charging system, thereby improving the overall operation safety of the charging system.

[0179] Furthermore, in one example, when the difference between the output power of one charging device and the required charging power of the load is greater than the difference between the output power of another charging device and the required charging power of the load, the average SOC value of one portion of the energy storage devices is greater than the average SOC value of the other portion of the energy storage devices. This not only increases the output power of the two charging devices, but also helps improve the SOC balance between the energy storage devices.

[0180] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A charging system, characterized in that, Comprising: A plurality of charging devices, a plurality of energy storage devices, and at least one switching module; Each of the charging devices includes an AC-DC conversion device, a DC bus, and a DC-DC conversion device. The AC-DC conversion device is configured to convert alternating current into direct current and output it to the DC bus, and the DC-DC conversion device is configured to obtain direct current from the DC bus and perform power conversion on the direct current and then output it to a load; Each of the energy storage devices is connected to the DC bus of each of the charging devices through the at least one switching module; The at least one switching module is configured to disconnect or conduct the connection between each of the energy storage devices and the DC bus of each of the charging devices, so as to perform power transfer between each of the energy storage devices and the DC bus of each of the charging devices.

2. The charging system according to claim 1, wherein The at least one switching module includes at least one first switching module and a plurality of second switching modules, Each of the energy storage devices is connected to one end of each of the second switching modules through the same first switching module, and the other ends of the plurality of second switching modules are connected to the DC buses of the plurality of charging devices in one-to-one correspondence; or, Each of the energy storage devices is connected to one end of each of the plurality of first switching modules, the other ends of the plurality of first switching modules are connected to one end of the plurality of second switching modules in one-to-one correspondence, and the other ends of the plurality of second switching modules are connected to the DC buses of the plurality of charging devices in one-to-one correspondence.

3. The charging system according to claim 2, wherein When one of the charging devices charges the load, in response to the output power of the one charging device being less than the charging demand power of the load, the at least one first switching module is configured to conduct the connection between the plurality of energy storage devices and the second switching module corresponding to the DC bus of the one charging device, and the second switching module corresponding to the DC bus of the one charging device is configured to conduct the connection between the energy storage device conducted by the at least one first switching module and the DC bus of the one charging device.

4. The charging system according to claim 3, characterized in that, The at least one first switching module is configured to conduct the connection between the plurality of energy storage devices and the second switching module corresponding to the DC bus of the one charging device, including: In response to the difference between the state of charge (SOC) of two of the energy storage devices being greater than a preset SOC difference, the at least one first switching module is configured to conduct the connection between the energy storage device with the largest SOC among the two energy storage devices and the second switching module corresponding to the DC bus of the one charging device; or, In response to the difference between the state of charge (SOC) of the two energy storage devices being less than or equal to the preset SOC difference, the at least one first switching module is configured to conduct the connection between each of the two energy storage devices and the second switching module corresponding to the DC bus of the one charging device.

5. The charging system according to claim 3 or 4, wherein When the one charging device and the other charging device respectively charge the load, in response to the output power of the one charging device and the output power of the other charging device being less than the charging demand power of the load, the at least one first switch module is configured to conduct the connection between a part of the plurality of energy storage devices and the second switch module corresponding to the DC bus of the one charging device, and conduct the connection between another part of the energy storage devices and the second switch module corresponding to the DC bus of the other charging device.

6. The charging system according to claim 5, wherein when the difference between the output power of the one charging device and the charging demand power of the load is greater than the difference between the output power of the other charging device and the charging demand power of the load, the average value of the SOC of the part of the energy storage devices is greater than the average value of the SOC of the other part of the energy storage devices.

7. A charging method, characterized in that, The charging method includes: when one charging device in the charging system charges a load, obtaining the charging demand power of the load; in response to the output power of the one charging device being less than the charging demand power of the load, controlling at least one switch module in the charging system to conduct the connection between the plurality of energy storage devices in the charging system and the DC bus of the one charging device, wherein the DC bus of the one charging device is configured to collect the direct current output by the AC-DC conversion device in the one charging device, and output the collected direct current to the load through the DC-DC conversion device.

8. The charging method according to claim 7, wherein The controlling at least one switch module in the charging system to conduct the connection between the plurality of energy storage devices and the DC bus of the one charging device includes: controlling at least one first switch module to conduct the connection between the plurality of energy storage devices and the second switch module corresponding to the DC bus of the one charging device, and controlling the second switch module corresponding to the DC bus of the one charging device to conduct the connection between the energy storage devices conducted by the at least one first switch module and the DC bus of the one charging device, wherein the at least one first switch module and the second switch module corresponding to the DC bus of the one charging device belong to the at least one switch module.

9. The charging method according to claim 8, wherein The controlling at least one first switch module to conduct the connection between the plurality of energy storage devices and the second switch module corresponding to the DC bus of the one charging device includes: in response to the difference between the state of charge (SOC) of two of the plurality of energy storage devices being greater than a preset SOC difference, controlling the at least one first switch module to conduct the connection between the energy storage device with the maximum SOC among the two energy storage devices and the second switch module corresponding to the DC bus of the one charging device; or in response to the difference between the state of charge (SOC) of the two energy storage devices being less than or equal to the preset SOC difference, controlling the at least one first switch module to conduct the connection between each of the two energy storage devices and the second switch module corresponding to the DC bus of the one charging device.

10. The charging method according to claims 8 and 9, characterized in that, The charging method further includes: When the one charging device and the other charging device in the charging system respectively charge the load, in response to the output power of the one charging device and the output power of the other charging device being less than the output power of the load, control the at least one first switch module to conduct the connection between a part of the energy storage devices in the multiple energy storage devices and the second switch module corresponding to the DC bus of the one charging device, and conduct the connection between another part of the energy storage devices and the second switch module corresponding to the DC bus of the other charging device.

11. The charging method according to claim 10, characterized in that, When the difference between the output power of the one charging device and the charging demand power of the load is greater than the difference between the output power of the other charging device and the charging demand power of the load, the average value of the SOC of the part of the energy storage devices is greater than the average value of the SOC of the other part of the energy storage devices.

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