Charging device

Abstract

The present application provides a charging device. The charging device comprises a plurality of first charging cabinets, a plurality of AC-DC conversion modules, a DC bus, and a plurality of groups of charging guns, wherein each of the plurality of first charging cabinets comprises a group of DC-DC conversion modules. An input end of each of the plurality of AC-DC conversion modules is configured to be connected to an output end of a corresponding transformer, and an output end of each AC-DC conversion module and an input end of each DC-DC conversion module in one group of DC-DC conversion modules are both connected to the DC bus. Output ends of one group of DC-DC conversion modules are connected to one group of charging guns among the plurality of groups of charging guns, and each group of the plurality of groups of charging guns are configured to be connected to vehicles to be charged. By means of the present application, the requirement of a higher power level can be satisfied, and the charging utilization rate of the charging device can also be increased.

Description

Charging equipment

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on December 14, 2023, with application number 202311722982.0, and priority to the Chinese patent application with the invention name “Charging Device”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of power supply technology, and in particular to a charging device. Background Art

[0003] With the widespread adoption of new energy vehicles, demand for high-power supercharging systems for electric vehicles is growing rapidly. Currently, high-power DC charging systems on the market primarily consist of a charging cabinet (i.e., a charging stack) with multiple charging terminals. The total output power of a charging cabinet ranges from 240 kW to 960 kW, and the trend is towards increasing power.

[0004] In current applications, to achieve a higher power level (e.g., 2MW to 4MW) supercharging station, several independent supercharging cabinets are generally deployed. Although this supercharging station can meet the demand for higher power levels, because the multiple charging cabinets are independent of each other, power sharing is impossible between the multiple charging cabinets. For example, if the pre-stage transformer capacity of charging cabinet A is limited, while the pre-stage transformer capacity of charging cabinet B is surplus, the surplus power cannot be utilized, resulting in a decrease in charging utilization.

[0005] In summary, it is particularly important to provide a charging device with a higher power level and high charging utilization rate. Summary of the Invention

[0006] The present application provides a charging device that can not only meet the demand for a higher power level, but also improve the charging utilization rate of the charging device.

[0007] In a first aspect, the present application provides a charging device, which includes a plurality of first charging cabinets, a plurality of AC-DC conversion modules, a DC bus, and a plurality of groups of charging guns, wherein each of the plurality of first charging cabinets includes a group of DC-DC conversion modules. The input end of each AC-DC conversion module in the plurality of AC-DC conversion modules is used to connect to the output end of the transformer, and the output end of each AC-DC conversion module and the input end of each DC-DC conversion module in a group of DC-DC conversion modules are connected to the DC bus. The output end of a group of DC-DC conversion modules is connected to a group of charging guns in a plurality of groups of charging guns, and each group of charging guns in the plurality of groups of charging guns is used to connect to a charging vehicle.

[0008] In this embodiment, the charging device pools the power capacity of the DC bus by having all AC-DC conversion modules in multiple AC-DC conversion modules and all DC-DC conversion modules in multiple first charging cabinets share the DC bus, so that when the input limiting power of different AC-DC conversion modules in the charging device is different and / or the output power of different first charging cabinets is different, the power on the DC bus can be flexibly distributed in the form of the entire charging device, thereby not only meeting the higher power level requirements of the charging device, but also maximizing the charging utilization rate of the charging device.

[0009] In combination with the first aspect, in a first possible implementation, the AC-DC conversion module is used to generate a modulation wave of the AC-DC conversion module based on an actual common-mode circulating current value of the AC-DC conversion module when a common-mode circulating current exists in the AC-DC conversion module, so as to reduce the common-mode circulating current of the AC-DC conversion module, wherein the modulation wave is used to control the switching tube in the AC-DC conversion module to be turned on or off.

[0010] In this embodiment, since each AC-DC conversion module in the charging device reduces its own actual common-mode circulating current through this low-frequency circulating current control method, the low-frequency circulating current between multiple AC-DC conversion modules can be reduced, thereby improving the efficiency, electromagnetic compatibility (EMC) and reliability of the charging device.

[0011] In combination with the first aspect or the first possible implementation manner of the first aspect, in a second possible implementation manner, the multiple groups of AC-DC conversion modules include an AC-DC conversion module i. The AC-DC conversion module i is configured to send a control signal of the AC-DC conversion module i to other AC-DC conversion modules in the multiple AC-DC conversion modules except the AC-DC conversion module i. Each of the other AC-DC conversion modules is configured to receive the control signal of the AC-DC conversion module i and control the control signal of each of the other AC-DC conversion modules to be aligned with the control signal of the AC-DC conversion module i.

[0012] In this embodiment, based on this high-frequency circulating current control method, the control signal of each of the other AC-DC conversion modules mentioned above can be aligned with the control signal of AC-DC conversion module i, thereby reducing the high-frequency circulating current between multiple AC-DC conversion modules and improving the efficiency, EMC and reliability of the charging equipment.

[0013] In combination with any one of the first aspect to the second possible implementation manner of the first aspect, in a third possible implementation manner, the AC-DC conversion module is used to control the ratio of the output power of the AC-DC conversion module i to the rated power to be a first ratio, wherein the first ratio is the ratio of the actual total output power of multiple AC-DC conversion modules to the total rated power.

[0014] In this embodiment, the charging device uses a proportional current sharing control method based on each AC-DC conversion module, so that the output power of each AC-DC conversion module is output proportionally based on its respective rated power size, so as to ensure that the AC-DC conversion module with a large rated power outputs more power and the AC-DC conversion module with a small rated power outputs less power, thereby extending the service life of each AC-DC conversion module and improving the reliability of the charging device.

[0015] In combination with any one of the first aspect to the third possible implementation scheme of the first aspect, in a fourth possible implementation scheme, the product of the total input power capacity of the charging device and the actual operating efficiency of the charging device is greater than or equal to the total output power of multiple groups of charging guns, wherein the total input power capacity of the charging device is the minimum value of the sum of the maximum input powers of multiple AC-DC conversion modules and the total rated power of the transformers connected to the multiple AC-DC conversion modules, and the actual operating efficiency of the charging device is the ratio of the total output power of multiple groups of charging guns to the total input power of the charging device.

[0016] In this embodiment, the product of the total input power capacity of the charging device and the actual operating efficiency of the charging device is greater than or equal to the total output power of multiple groups of charging guns. It can be obtained that the total output power capacity of the charging device (that is, the maximum total output power of the charging device) is greater than or equal to the total output power of multiple groups of charging guns. When the total output power of the multiple groups of charging guns is too large, the charging device stops working because it cannot meet the total output power of the multiple groups of charging guns, thereby improving the reliability of the charging device.

[0017] In combination with any one of the second possible implementation manner of the first aspect to the fourth possible implementation manner of the first aspect, in a fifth possible implementation manner, the charging device further includes a parallel communication line, and each AC-DC conversion module is connected to the parallel communication line. The parallel communication line is used to transmit the rated power or actual output power of any one of the multiple AC-DC conversion modules.

[0018] In this embodiment, the charging device sets a parallel communication line between each AC-DC conversion module to facilitate subsequent proportional current sharing control among all AC-DC conversion modules in the charging device, thereby improving the working efficiency of the charging device.

[0019] In conjunction with the fifth possible implementation of the first aspect, in a sixth possible implementation, the charging device further includes a carrier synchronization line or a power frequency synchronization line, and each AC-DC conversion module is connected to the carrier synchronization line or the power frequency synchronization line. The carrier synchronization line is used to transmit control signals for AC-DC conversion module i, and the power frequency synchronization line is used to transmit input voltage phase information for any AC-DC conversion module.

[0020] In this embodiment, when the circuit topology type of each AC-DC conversion module in the charging device is a non-isolated type, a carrier synchronization line or a power frequency synchronization line is further provided between each AC-DC conversion module in the charging device to facilitate subsequent implementation of high-frequency carrier synchronization, power frequency phase detection and synchronization, and low-frequency band circulating current control among all AC-DC conversion modules in the charging device, thereby achieving circulating current control among all AC-DC conversion modules in the charging device, reducing high-frequency and low-frequency circulating currents between parallel machines, and thereby improving the efficiency, EMC, and reliability of the charging device.

[0021] In combination with any one of the first aspect to the sixth possible implementation of the first aspect, in a seventh possible implementation, the multiple AC-DC conversion modules include N groups of AC-DC conversion modules, the number of the multiple first charging cabinets is N, and each first charging cabinet also includes a group of AC-DC conversion modules.

[0022] In this embodiment, the charging device includes N first charging cabinets, each of which includes a group of AC-DC conversion modules and a group of DC-DC conversion modules. The first charging cabinet in this embodiment is a DC charging cabinet, and the charging device can be applied to a discrete DC charging pile system.

[0023] In combination with any one of the first aspect to the sixth possible implementation of the first aspect, in an eighth possible implementation, the multiple AC-DC conversion modules include M groups of AC-DC conversion modules, the charging device also includes M second charging cabinets, and each of the M second charging cabinets includes a group of AC-DC conversion modules.

[0024] In this embodiment, a group of AC-DC conversion modules are located in a second charging cabinet, and a group of DC-DC conversion modules are located in a first charging cabinet. The charging cabinets have diverse structures, which makes the charging equipment structure diverse and highly flexible.

[0025] In combination with the seventh possible implementation manner of the first aspect or the eighth possible implementation manner of the first aspect, in a ninth possible implementation manner, each first charging cabinet further includes a controller, the group of charging guns connected to each first charging cabinet includes multiple charging guns, and the group of DC-DC conversion modules in each first charging cabinet includes multiple DC-DC conversion modules. The controller is configured to control the output power of a DC-DC conversion module corresponding to each first charging gun, or the total output power of the multiple DC-DC conversion modules, to the product of the charging power required by the charging vehicle connected to each first charging gun and a power attenuation coefficient, in response to the total rated power of the multiple AC-DC conversion modules being less than or equal to the total charging power required by the charging vehicles connected to the multiple groups of charging guns. The first charging gun is a charging gun among the multiple charging guns that is connected to the charging vehicle, and the power attenuation coefficient is less than or equal to the ratio of the total rated power to the total charging power.

[0026] In this embodiment, when the total rated power of all AC-DC conversion modules in the charging device is less than or equal to the total charging power of all vehicles connected to the charging gun, the device outputs a proportional portion of the required charging power to each vehicle connected to the charging gun. This prevents individual vehicles from being unable to charge, thereby ensuring that each vehicle connected to the charging gun is fully charged and enhancing the user's charging experience. Furthermore, by outputting a proportional portion of the required charging power to each vehicle connected to the charging gun, the charging device ensures that the power input to the DC bus is always greater than or equal to the power output from the DC bus when charging a vehicle, thereby further improving the reliability of the charging device.

[0027] In combination with the seventh possible implementation manner of the first aspect or the eighth possible implementation manner of the first aspect, in a tenth possible implementation manner, each first charging cabinet further includes a controller, a group of charging guns connected to each first charging cabinet includes multiple charging guns, and a group of DC-DC conversion modules in each first charging cabinet includes multiple DC-DC conversion modules. The controller is configured to control the output power of a DC-DC conversion module corresponding to each first charging gun, or the total output power of the multiple DC-DC conversion modules, to the charging power required by the charging vehicle connected to each first charging gun, in response to a total rated power of the multiple AC-DC conversion modules being greater than a total charging power required by the charging vehicles connected to the multiple groups of charging guns, wherein the first charging gun is a charging gun among the multiple charging guns that is connected to the charging vehicle.

[0028] In this embodiment, when the total rated power of all AC-DC converter modules in the charging device exceeds the total charging power of all connected vehicles, the charging device effectively improves the charging efficiency of each vehicle by delivering the required charging power to each connected vehicle, thereby enhancing the user's charging experience. Furthermore, the power input to the DC bus is always greater than or equal to the power output from the DC bus, further improving the reliability of the charging device. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG1 is a schematic diagram of an application scenario of a charging device provided by this application;

[0030] FIG2 is a schematic structural diagram of a charging device provided by the present application;

[0031] FIG3 is another structural schematic diagram of the charging device provided by the present application;

[0032] FIG4 is a schematic diagram of common-mode circulating current provided by the present application;

[0033] FIG5 is a schematic diagram of the control logic of the common-mode circulating current provided by the present application;

[0034] FIG6 is another structural diagram of the charging device provided in this application. DETAILED DESCRIPTION

[0035] The charging equipment provided in this application can be applied to various application fields such as the field of new energy electric vehicles, the field of photovoltaic power generation, and the field of energy storage power generation. The charging equipment provided in this application is applicable to different application scenarios, such as electric vehicle power supply scenarios (including discrete DC charging pile power supply scenarios, high-power supercharging station power supply scenarios, etc.), light charging power supply scenarios (i.e., power supply scenarios with photovoltaic systems superimposed on charging equipment), storage charging power supply scenarios (i.e., power supply scenarios with energy storage systems superimposed on charging equipment), light storage charging power supply scenarios (i.e., power supply scenarios with photovoltaic systems and energy storage systems superimposed on charging equipment), etc. The following is an example of the power supply scenario of electric vehicles.

[0036] Refer to Figure 1, which is a schematic diagram of the application scenario of the charging device provided by the present application. In the electric vehicle power supply scenario, the charging device provided by the present application may be the charging device 1 shown in Figure 1, which includes multiple first charging cabinets, multiple AC-DC conversion modules, a DC bus and multiple groups of charging guns. Each of the multiple first charging cabinets includes a group of DC-DC conversion modules. The multiple first charging cabinets provided by the present application are N charging cabinets, from charging cabinet 11 to charging cabinet 1N shown in Figure 1, where N is an integer greater than 1. The multiple AC-DC conversion modules provided by the present application are all AC-DC conversion modules in the charging device 1 shown in Figure 1. The DC bus provided by the present application is the DC bus BUS shown in Figure 1. The group of charging guns provided by the present application is the charging guns of all charging terminals connected to any one of the charging cabinets shown in Figure 1. The multiple groups of charging guns provided by the present application are the charging guns of all charging terminals connected to the N charging cabinets shown in Figure 1. The group of DC-DC conversion modules provided by the present application is all DC-DC conversion modules in any one of the charging cabinets shown in Figure 1. Each charging cabinet also includes a composite switching matrix.

[0037] The input of each AC-DC conversion module in charging cabinet 11 is connected to the output of the transformer via the input of charging cabinet 11. The output of each AC-DC conversion module and the input of each DC-DC conversion module in charging cabinet 11 are both connected to the DC bus BUS. The output of each DC-DC conversion module in charging cabinet 11 is connected to the output of charging cabinet 11 via the composite switching matrix in charging cabinet 11. .... The input of each AC-DC conversion module in charging cabinet 1N is connected to the output of the transformer via the input of charging cabinet 1N. The output of each AC-DC conversion module and the input of each DC-DC conversion module in charging cabinet 1N are both connected to the DC bus BUS. The output of each DC-DC conversion module in charging cabinet 1N is connected to the output of charging cabinet 1N via the composite switching matrix in charging cabinet 1N. The output of each of the N charging cabinets is connected to an electric vehicle via multiple charging terminals. The inputs of the N transformers connected to the N charging cabinets are all connected to the AC power grid.

[0038] After charging device 1 begins operation, each of the N transformers steps down the AC power from the AC grid and outputs it to the input of its connected charging cabinet. Each of the N charging cabinets rectifies the AC power at its input via its own multiple AC-DC conversion modules and outputs it to the DC bus BUS. Based on the charging power it needs to deliver to the electric vehicles to be charged, each charging cabinet controls the switching operations within the composite switching matrix and the output power of the DC-DC conversion modules connected to the closed switches within the composite switching matrix to meet the charging needs of the corresponding electric vehicles to be charged.

[0039] It is understandable that the charging device 1 pools the power capacity of the DC bus BUS by sharing the DC bus BUS among N charging cabinets. This allows the power on the DC bus BUS to be flexibly distributed across the entire charging device when different charging cabinets in the charging device 1 have different input power limits and / or different output powers. This not only meets the higher power level requirements of the charging device 1, but also maximizes the charging efficiency of the charging device 1. The above is merely an example of the application scenarios of the charging device provided by this application, and is not an exhaustive list. This application does not limit the application scenarios.

[0040] The working principle of the charging device provided in this application is illustrated below with reference to Figures 2 to 6.

[0041] Refer to Figure 2, which is a schematic diagram of the structure of the charging device provided by this application. As shown in Figure 2, the charging device 1 includes N first charging cabinets, Q AC-DC conversion modules, a DC bus BUS and N groups of charging guns, where N and Q are both integers greater than 1. Among them, the N first charging cabinets correspond to the first charging cabinets 11, ..., and the first charging cabinet 1N shown in Figure 2. The Q AC-DC conversion modules include AC-DC conversion modules 111a1, ..., AC-DC conversion modules 111a i , ..., AC-DC conversion module 1N1d1, ..., AC-DC conversion module 1N1d l The N groups of charging guns include the first group of charging guns, ..., the Nth group of charging guns, wherein the charging guns 113c1, ..., and 113c shown in FIG. 2 are k The first group of charging guns is formed; ...; the charging guns 1N3f1, ..., and 1N3f shown in FIG. 2 q Each of the N first charging cabinets includes a set of DC-DC conversion modules. Specifically, the first charging cabinet 11 includes a DC-DC conversion module 112b1, ..., a DC-DC conversion module 112b j The first group of DC-DC conversion modules is composed of: ...; the first charging cabinet 1N includes a DC-DC conversion module 1N2e1, ..., a DC-DC conversion module 1N2e p The DC bus BUS provided in this application is a high-voltage DC bus. Exemplarily, the voltage of the DC bus BUS is 800 V. Wherein, i, j, k, l, p, and q are all integers greater than 1, and this application does not limit the relationship between any two of i, j, k, l, p, and q.

[0042] The input end of each of the Q AC-DC conversion modules is used to connect to the output end of the transformer. Specifically, the input end of the AC-DC conversion module 111a1, ..., the input end of the AC-DC conversion module 111a i The input ends of the AC-DC conversion module 1N1d1 are connected to the output end of the transformer 21; ...; the input end of the AC-DC conversion module 1N1d1, ..., the AC-DC conversion module 1N1d l The input ends of the transformer 2N are all connected to the output ends of the transformer 2N. The input ends of the transformer 21, ..., and the input ends of the transformer 2N are all connected to the AC power grid. The output end of each AC-DC conversion module in the Q AC-DC conversion modules, the input ends of the j DC-DC conversion modules in the first group of DC-DC conversion modules, ..., and the input ends of the p DC-DC conversion modules in the Nth group of DC-DC conversion modules are all connected to the DC bus BUS. The output ends of a group of DC-DC conversion modules in each first charging cabinet are connected to a group of charging guns in the N groups of charging guns. Specifically, the output ends of the j DC-DC conversion modules in the first group of DC-DC conversion modules are connected to the k charging guns in the first group of charging guns by connecting to the input ends of the charging terminal where the first group of charging guns are located; ...; the output ends of the p DC-DC conversion modules in the Nth group of DC-DC conversion modules are connected to the q charging guns in the Nth group of charging guns by connecting to the input ends of the charging terminal where the Nth group of charging guns are located. Each charging gun in each group of charging guns is used to connect to a charging vehicle.

[0043] It should be noted that the connection between A and B in this application can be a direct connection between A and B, or an indirect connection between A and B through C, and this application does not impose any restrictions on this. In addition, the rated power of the above-mentioned N transformers can be the same or different. The charging device 1 provided in this application does not impose any restrictions on the difference between the rated power of the AC-DC conversion module and the rated power of the DC-DC conversion module.

[0044] In an embodiment of the present application, the charging device 1 pools the power capacity of the DC bus BUS by having all AC-DC conversion modules share the DC bus BUS with all DC-DC conversion modules in N first charging cabinets, so that when the input limiting power of different AC-DC conversion modules in the charging device 1 is different and / or the output power of different first charging cabinets is different, the power on the DC bus BUS can be flexibly distributed in the form of the entire charging device, thereby not only meeting the higher power level requirements of the charging device 1, but also maximizing the charging utilization rate of the charging device 1.

[0045] For example, refer to Figure 3, which is another structural diagram of the charging device provided in this application. As shown in Figure 3, compared with the charging device 1 shown in Figure 2, the Q AC-DC conversion modules in the charging device 1 shown in Figure 3 are divided into N groups of AC-DC conversion modules, and each first charging cabinet also includes a group of AC-DC conversion modules, a controller and a compound switching matrix. Specifically, as shown in Figure 3, the first charging cabinet 11 also includes a first group of AC-DC conversion modules, a controller 114 and a compound switching matrix 115, ..., the first charging cabinet 1N also includes the Nth group of AC-DC conversion modules, a controller 1N4 and a compound switching matrix 1N5. Among them, the first group of AC-DC conversion modules includes AC-DC conversion modules 111a1, ..., AC-DC conversion modules 111a i The input terminals of the i AC-DC conversion modules in the first group of AC-DC conversion modules are connected to the output terminal of the transformer 21 through the input terminal of the first charging cabinet 11; ...; the Nth group of AC-DC conversion modules includes AC-DC conversion modules 1N1d1, ..., AC-DC conversion modules 1N1d l The input terminals of the first AC-DC conversion modules in the Nth group are connected to the output terminals of the transformer 2N through the input terminals of the first charging cabinet 1N. The controllers 114, ..., and 1N4 establish communication connections with each other via wired (such as CAN bus) or wireless (such as 4G, Wi-Fi, etc.) to facilitate the scheduling and control of the total input power and total output power of the charging device 1. Here, the controllers in this application are all energy management systems (EMS). The j DC-DC conversion modules in the first group of DC-DC conversion modules are connected to the output terminals of the first charging cabinet 11 via a composite switching matrix 115. The output terminals of the first charging cabinet 11 are connected to the k charging guns in the first group of charging guns by connecting to the charging terminals where the first group of charging guns are located. ...; the p DC-DC conversion modules in the Nth group of DC-DC conversion modules are connected to the output terminals of the first charging cabinet 1N via a composite switching matrix 1N5. The output terminals of the first charging cabinet 1N are connected to the q charging guns in the Nth group of charging guns by connecting to the charging terminals where the Nth group of charging guns are located. Optionally, the N first charging cabinets may be connected to the same transformer; optionally, one of the N first charging cabinets may be connected to multiple transformers. Optionally, the multiple DC-DC conversion modules in each first charging cabinet may be connected to the output end of each first charging cabinet in a fixed switching manner.

[0046] Since the input ends of different first charging cabinets are connected to different transformers, the input ends of different transformers are all connected to the AC power grid. Also, since the outputs of different transformers have phase differences, and the various AC-DC conversion modules in the charging device 1 share a common DC bus BUS, when the circuit topology types of the various AC-DC conversion modules in the charging device 1 are all non-isolated types and the N lines of different transformers have a common grounding network, a common-mode circulating current as shown in FIG4 will appear. The common-mode circulating current includes a low-frequency circulating current or a high-frequency circulating current. Based on this, when the circuit topology types of the various AC-DC conversion modules in the charging device 1 are all non-isolated types, the charging device 1 shown in FIG3 also provides a parallel signal bus, and each AC-DC conversion module in the charging device 1 is connected to the parallel signal bus. The parallel signal bus includes but is not limited to signal lines such as a carrier synchronization line or an industrial frequency synchronization line. The carrier synchronization line is used to transmit control signals from the master module of the Q AC-DC conversion modules, thereby synchronizing the switching signals between the various AC-DC conversion modules in the charging device 1 and thus achieving high-frequency circulating current control between different first charging cabinets. The power frequency synchronization line is used to transmit input voltage phase information of any AC-DC conversion module in the charging device 1. Furthermore, regardless of whether the circuit topology of each AC-DC conversion module is isolated or non-isolated, the parallel signal bus always includes a parallel communication line. The parallel communication line is used to transmit the rated power or actual output power of any AC-DC conversion module in the charging device 1 to achieve proportional current sharing control between the various AC-DC conversion modules in the charging device 1. It should be noted that when the circuit topology of each AC-DC conversion module in the charging device 1 is isolated, no common-mode circulating current will exist between different first charging cabinets. Therefore, when the circuit topology of each AC-DC conversion module in the charging device 1 is isolated, the carrier synchronization line and the power frequency synchronization line can be omitted from the parallel signal bus.

[0047] In one embodiment, the low-frequency circulating current control method of charging device 1 is as follows: After charging device 1 is in operation, each AC-DC conversion module in charging device 1 generates its own modulation wave based on its actual common-mode circulating current value in the presence of common-mode circulating current, thereby reducing its own common-mode circulating current. Because the low-frequency circulating current control method of each AC-DC conversion module in charging device 1 is consistent, for ease of description, the following description uses AC-DC conversion module 111a1 as an example.

[0048] Specifically, please refer to FIG5 , which is a schematic diagram of the control logic of the common-mode circulating current provided by the present application. As shown in FIG5 , after the charging device 1 is working, the AC-DC conversion module 111a1 superimposes the three-phase input current of the AC-DC conversion module 111a1 to obtain the actual common-mode circulating current value Icom1 of the AC-DC conversion module 111a1, or obtains the actual common-mode circulating current value Icom1 of the AC-DC conversion module 111a1 through the residual current detection device RCD1, and when the actual common-mode circulating current value Icom1 of the AC-DC conversion module 111a1 is not 0, the AC-DC conversion module 111a1 is described. If common-mode circulating current exists in 111a1, the deviation between the actual common-mode circulating current value Icom1 of the AC-DC conversion module 111a1 and the target common-mode circulating current value Icomref is processed by a PI controller to obtain a common-mode circulating current modulation voltage for the AC-DC conversion module 111a1. This common-mode circulating current modulation voltage is then superimposed on the initial three-phase modulation wave A0 of the AC-DC conversion module 111a1, thereby obtaining a modulation wave A1 of the AC-DC conversion module 111a1. The initial three-phase modulation wave A0 of the AC-DC conversion module 111a1 may be a modulation wave generated based on the reference output voltage of the AC-DC conversion module 111a1. For example, the target common-mode circulating current value Icomref is 0. The AC-DC conversion module 111a1 then outputs the modulation wave A1 to its own controllable switch transistor to reduce the deviation between its actual common-mode circulating current value and the target common-mode circulating current value, thereby reducing its own common-mode circulating current. Since each AC-DC conversion module in the charging device 1 reduces its own actual common-mode circulating current through this low-frequency circulating current control method, the low-frequency circulating current between the N first charging cabinets can be reduced to improve the efficiency, EMC and reliability of the charging device 1.

[0049] In one embodiment, all AC-DC conversion modules in the charging device 1 are composed of the AC-DC conversion module 1N1d1 and other AC-DC conversion modules except the AC-DC conversion module 1N1d1, wherein the AC-DC conversion module 1N1d1 is the master module of the AC-DC conversion module in the charging device 1, and the other AC-DC conversion modules except the AC-DC conversion module 1N1d1 are slave modules of the AC-DC conversion module 1N1d1.

[0050] The high-frequency circulating current control method of charging device 1 is as follows: After charging device 1 is in operation, AC-DC conversion module 1N1d1 transmits a control signal from AC-DC conversion module 1N1d1 to each of the other AC-DC conversion modules via a carrier synchronization line. Each of the other AC-DC conversion modules receives the control signal from AC-DC conversion module 1N1d1 via the carrier synchronization line and aligns its own control signal with the control signal from AC-DC conversion module 1N1d1 to achieve high-frequency circulating current control between different AC-DC conversion modules. Because the high-frequency circulating current control method of each AC-DC conversion module in the other first power conversion is consistent, for ease of description, the following description uses AC-DC conversion module 111a1 as an example.

[0051] Specifically, as shown in Figure 5, after charging device 1 is operational, AC-DC conversion module 111a1 receives the control signal from AC-DC conversion module 1N1d1 via the carrier synchronization line and aligns the rising edge of its own control signal with that of AC-DC conversion module 1N1d1, thereby aligning its own control signal with that of AC-DC conversion module 1N1d1. This high-frequency circulating current control method aligns the control signal of each of the other AC-DC conversion modules described above with the control signal of AC-DC conversion module 1N1d1, thereby reducing high-frequency circulating currents between the N first charging cabinets and improving the efficiency, EMC, and reliability of charging device 1.

[0052] In one embodiment, the proportional current sharing control method for each AC-DC conversion module in the charging device 1 is as follows: after the charging device 1 is in operation, each AC-DC conversion module in the charging device 1 obtains the rated power and actual output power of all AC-DC conversion modules other than itself through the parallel communication line, and determines the ratio of the actual total output power of all AC-DC conversion modules in the charging device 1 to the total rated power as a first ratio, thereby controlling its own output power to be the product of its own rated power and the first ratio, thereby achieving proportional current sharing control for each AC-DC conversion module. In this application, the rated power of each AC-DC conversion module can be the same or different.

[0053] For example, assuming N=i=l=2, the charging device 1 includes a first charging cabinet 11 and a first charging cabinet 12. The first charging cabinet 11 includes an AC-DC conversion module 111a1 and an AC-DC conversion module 111a2, and the first charging cabinet 12 includes an AC-DC conversion module 121d1 and an AC-DC conversion module 121d2. The rated power and actual output power of the AC-DC conversion module 111a1 are 100 kW and 80 kW, respectively. The rated power and actual output power of the AC-DC conversion module 111a2 are 150 kW and 100 kW, respectively. The rated power and actual output power of the AC-DC conversion module 121d1 are 150 kW and 120 kW, respectively. The rated power and actual output power of the AC-DC conversion module 121d2 are 100 kW and 80 kW, respectively. Then, the first ratio calculated by each of the above four AC-DC conversion modules is (80+100+120+80) / (100+150+150+100)=0.76. The output power of the AC-DC conversion module 111a1 is controlled to be 100*0.76=76KW, the output power of the AC-DC conversion module 111a2 is controlled to be 150*0.76=114KW, the output power of the AC-DC conversion module 121d1 is controlled to be 150*0.76=114KW, and the output power of the AC-DC conversion module 121d2 is controlled to be 100*0.76=76KW.

[0054] It can be understood that the charging device 1, based on the proportional current sharing control method of each AC-DC conversion module, can make the output power of each AC-DC conversion module output proportionally based on its respective rated power size, so as to ensure that the AC-DC conversion module with a large rated power outputs more power and the AC-DC conversion module with a small rated power outputs less power, thereby extending the service life of each AC-DC conversion module and improving the reliability of the charging device 1.

[0055] In addition, when the charging gun of the charging device 1 is connected to the charging vehicle, it controls the output power of the DC-DC conversion module connected to the charging vehicle through proportional distribution or on-demand distribution to ensure that the power input to the DC bus BUS of the charging device 1 when charging the charging vehicle is always greater than or equal to the power output from the DC bus BUS, thereby improving the reliability of the charging device 1.

[0056] In an optional embodiment, in response to the total rated power of all AC-DC conversion modules in the charging device 1 being less than or equal to the total charging power required by all charging vehicles connected to the charging guns in the charging device 1, the controller in each first charging cabinet controls the output power of a DC-DC conversion module corresponding to each first charging gun, or the total output power of multiple DC-DC conversion modules, to be the product of the charging power required by the charging vehicle connected to each first charging gun and a power attenuation coefficient, wherein the first charging gun is a charging gun connected to a charging vehicle in each first charging cabinet. The power attenuation coefficient is greater than a preset threshold and less than or equal to a second ratio, which is the ratio of the total rated power of all AC-DC conversion modules to the total charging power required by all charging vehicles connected to the charging guns. Exemplarily, the preset threshold is 0.

[0057] For example, assuming that the power attenuation coefficient is the second ratio, all the charging guns in the charging device 1 are only the charging gun 113c1 and the charging gun 1N3f q Connect the charging vehicle, the DC-DC conversion module corresponding to the charging gun 113c1 is the DC-DC conversion module 112b1 and the DC-DC conversion module 112b3, and the charging gun 1N3f q The corresponding DC-DC conversion module is DC-DC conversion module 1N2e p The charging power required by the charging vehicle connected to the charging gun 113c1 is 400KW, and the charging gun 1N3f q The charging power required to connect the charging vehicle is 300KW. The total rated power of all AC-DC conversion modules in the charging device 1 is 560KW. Obviously, the total rated power of all AC-DC conversion modules in the charging device 1, 560KW, is less than the total charging power of all charging vehicles connected to the charging guns in the charging device 1, that is, 400+300=700KW. Then the controller 114 in the first charging cabinet 11 and the controller 1N4 in the first charging cabinet 1N calculate the second ratio to be 560 / 700=0.8. The controller 114 controls the total output power of the DC-DC conversion module 112b1 and the DC-DC conversion module 112b3, that is, the sum of the output power of the DC-DC conversion module 112b1 and the output power of the DC-DC conversion module 112b3, which is the product of the charging power of 400KW required by the charging vehicle connected to the charging gun 113c1 and the second ratio of 0.8, that is, 320KW. The controller 1N4 controls the DC-DC conversion module 1N2e p The output power of the charging gun is 1N3f q The product of the charging power 300 kW required for connecting the charging vehicle and the second ratio 0.8 is 240 kW.

[0058] It is understood that when the total rated power of all AC-DC conversion modules in charging device 1 is less than or equal to the total charging power of all charging vehicles connected to the charging gun in charging device 1, by outputting a proportional portion of the required charging power to each charging vehicle connected to the charging gun, the situation where individual charging vehicles connected to the charging gun cannot be charged is avoided, thereby ensuring that each charging vehicle connected to the charging gun can be in a charging state, thereby improving the user's charging experience. In addition, by outputting a proportional portion of the required charging power to each charging vehicle connected to the charging gun, charging device 1 can ensure that the power input to the DC bus BUS of charging device 1 is always greater than or equal to the power output from the DC bus BUS when charging the charging vehicle, thereby also improving the reliability of charging device 1.

[0059] In another optional embodiment, the controller in each first charging cabinet controls the output power of a DC-DC conversion module corresponding to each first charging gun or the total output power of multiple DC-DC conversion modules to be the charging power required by the charging vehicle connected to each first charging gun in response to the total rated power of all AC-DC conversion modules in the charging device 1 being greater than the total charging power required by the charging vehicles connected to all charging guns in the charging device 1, wherein the first charging gun is the charging gun connected to the charging vehicle in each first charging cabinet.

[0060] For example, it is assumed that all charging guns in the charging device 1 are only charging gun 113c1 and charging gun 1N3f. q Connect the charging vehicle, the DC-DC conversion module corresponding to the charging gun 113c1 is the DC-DC conversion module 112b1 and the DC-DC conversion module 112b3, and the charging gun 1N3f q The corresponding DC-DC conversion module is DC-DC conversion module 1N2e p The charging power required by the charging vehicle connected to the charging gun 113c1 is 400KW, and the charging gun 1N3f q The charging power required to connect the charging vehicle is 300KW. The total rated power of all AC-DC conversion modules in the charging device 1 is 800KW. Obviously, the total rated power of 800KW of all AC-DC conversion modules in the charging device 1 is greater than the total charging power of all charging vehicles connected to the charging guns in the charging device 1, that is, 400+300=700KW, then the controller 114 in the first charging cabinet 11 controls the total output power of the DC-DC conversion module 112b1 and the DC-DC conversion module 112b3, that is, the sum of the output power of the DC-DC conversion module 112b1 and the output power of the DC-DC conversion module 112b3, which is the charging power of 400KW required for the charging vehicle connected to the charging gun 113c1. The controller 1N4 in the first charging cabinet 1N controls the DC-DC conversion module 1N2e pThe output power of the charging gun is 1N3f q The charging power required to connect the charging vehicle is 300KW.

[0061] It can be understood that when the total rated power of all AC-DC conversion modules in charging device 1 exceeds the total charging power of all vehicles connected to the charging guns of charging device 1, by outputting the required charging power to each connected vehicle, the charging efficiency of charging device 1 for each vehicle can be effectively improved, thereby enhancing the user's charging experience. In addition, when charging a vehicle, the power input to the DC bus of charging device 1 is always greater than or equal to the power output from the DC bus, which also improves the reliability of charging device 1.

[0062] Furthermore, the product of the total input power capacity of the charging device 1 and its actual operating efficiency is greater than or equal to the total output power of all charging plugs in the charging device 1. The total input power capacity of the charging device 1 is the minimum of the sum of the maximum input power of each AC-DC conversion module in the charging device 1 and the total rated power of the transformers connected to all the AC-DC conversion modules in the charging device 1. This ensures that the total output power capacity of the charging device 1 (i.e., the maximum total output power of the charging device 1) is greater than or equal to the total output power of all the charging plugs in the charging device 1. This prevents the charging device 1 from shutting down due to an inability to meet the total output power of all the charging plugs in the charging device 1 when the total output power of all the charging plugs in the charging device 1 is excessive, thereby improving the reliability of the charging device 1. The controller in each first charging cabinet is also configured to control the total input power of all the AC-DC conversion modules in the cabinet to not exceed the rated power of the transformer connected to the first charging cabinet in which it resides, ensuring that the transformers connected to each first charging cabinet do not operate beyond their rated capacity, thereby improving the reliability of the charging device 1.

[0063] In the embodiment of the present application, the charging device 1 pools the power capacity of the DC bus BUS by having all AC-DC conversion modules and all DC-DC conversion modules in N first charging cabinets share the DC bus BUS. This allows the power on the DC bus BUS to be flexibly distributed as a whole in the form of the entire charging device when different first charging cabinets in the charging device 1 have different input power limits and / or different output powers. This not only meets the higher power level requirements of the charging device 1, but also maximizes the charging utilization rate of the charging device 1. In addition, the charging device 1 sets parallel communication lines between the various AC-DC conversion modules to achieve proportional current sharing control between the various first power conversion modes, thereby improving the efficiency of the charging device 1. When the circuit topology of each AC-DC converter module in charging device 1 is non-isolated, carrier synchronization lines or power frequency synchronization lines are provided between the modules to implement high-frequency carrier synchronization, power frequency phase detection and synchronization, and low-frequency circulating current control among the non-isolated AC-DC converter modules in charging device 1. This allows for circulating current control between the N first charging cabinets, reducing high- and low-frequency circulating currents between parallel units, thereby improving the efficiency, EMC, and reliability of charging device 1. Furthermore, when charging a vehicle, the power input to the DC bus BUS of charging device 1 is always greater than or equal to the power output from the DC bus BUS, further improving the reliability of charging device 1.

[0064] For example, refer to Figure 6, which is another structural diagram of the charging device provided by the present application. As shown in Figure 6, compared with the charging device 1 shown in Figure 2, the Q AC-DC conversion modules in the charging device 1 shown in Figure 6 are divided into M groups of AC-DC conversion modules, and the charging device 1 also includes M second charging cabinets, and each of the M second charging cabinets includes a group of AC-DC conversion modules. Here, M and N are both integers greater than 1, and the present application does not limit the size relationship between M and N. Specifically, as shown in Figure 6, the charging device 1 also includes a second charging cabinet 31, ..., a second charging cabinet 3M, and the second charging cabinet 31 includes a first group of AC-DC conversion modules, ..., and the second charging cabinet 3M includes the Mth group of AC-DC conversion modules. Among them, the first group of AC-DC conversion modules includes AC-DC conversion modules 111a1, ..., AC-DC conversion modules 111a i ...; The Mth group of AC-DC conversion modules includes AC-DC conversion module 1M1g1, ..., AC-DC conversion module 1M1g r Here, i and r are both integers greater than 1, and this application does not impose any restrictions on the size relationship between i and r.

[0065] The output ends of each AC-DC conversion module in the M second charging cabinets are connected to the DC bus BUS. Specifically, the output ends of the i AC-DC conversion modules in the second charging cabinet 31 are connected to the DC bus BUS via the output end of the second charging cabinet 31; ...; the output ends of the r AC-DC conversion modules in the second charging cabinet 3M are connected to the DC bus BUS via the output end of the second charging cabinet 3M. The input ends of the i AC-DC conversion modules in the second charging cabinet 31 are connected and then connected to the output end of the transformer 21 via the input end of the second charging cabinet 31; ...; the input ends of the r AC-DC conversion modules in the second charging cabinet 3M are connected and then connected to the output end of the transformer 2M via the input end of the second charging cabinet 3M. The second charging cabinet 31 also includes a controller 311, ..., and the second charging cabinet 3M also includes a controller 3M1.

[0066] The input ends of each DC-DC conversion module in the N first charging cabinets are connected to the DC bus BUS. Specifically, the input ends of the j DC-DC conversion modules in the first charging cabinet 11 are connected to the DC bus BUS via the input ends of the first charging cabinet 11; ...; the input ends of the p DC-DC conversion modules in the first charging cabinet 1N are connected to the DC bus BUS via the input ends of the first charging cabinet 1N. Here, the connection relationship between the DC-DC conversion modules in each first charging cabinet and the composite switching matrix, as well as the connection relationship between the N first charging cabinets and the N groups of charging guns, can be found in the description of the corresponding parts of the charging device 1 shown in Figure 3, and will not be repeated here.

[0067] In addition, each controller in the N first charging cabinets establishes a communication connection with each controller in the M second charging cabinets through a wired method (such as CAN bus) or a wireless method (such as 4G, wifi, etc.) to facilitate the scheduling and control of the total input power and total output power of the charging device 1.

[0068] Since the input ends of different second charging cabinets are connected to different transformers, the input ends of different transformers are all connected to the AC power grid. Also, since the outputs of different transformers have phase differences, and the various AC-DC conversion modules in the charging device 1 share a common DC bus BUS, when the circuit topology types of the various AC-DC conversion modules in the charging device 1 are all non-isolated types and the N lines of the different transformers have a common grounding network, a common-mode circulating current as shown in FIG4 will appear. The common-mode circulating current includes a low-frequency circulating current or a high-frequency circulating current. Based on this, when the circuit topology types of the various AC-DC conversion modules in the charging device 1 are all non-isolated types, the charging device 1 shown in FIG6 also provides a parallel signal bus, and each AC-DC conversion module in the charging device 1 is connected to the parallel signal bus. The parallel signal bus includes but is not limited to signal lines such as a carrier synchronization line or an industrial frequency synchronization line. The carrier synchronization line is used to transmit control signals from the master module of the Q AC-DC conversion modules, thereby synchronizing the switching signals between the various AC-DC conversion modules in the charging device 1 and thus achieving high-frequency circulating current control between different secondary charging cabinets. The power frequency synchronization line is used to transmit input voltage phase information of any AC-DC conversion module in the charging device 1. Furthermore, regardless of whether the circuit topology of each AC-DC conversion module is isolated or non-isolated, the parallel signal bus always includes a parallel communication line. The parallel communication line is used to transmit the rated power or actual output power of any AC-DC conversion module in the charging device 1 to achieve proportional current sharing control between the various AC-DC conversion modules in the charging device 1. It should be noted that when the circuit topology of each AC-DC conversion module in the charging device 1 is isolated, no common-mode circulating current will exist between different secondary charging cabinets. Therefore, when the circuit topology of each AC-DC conversion module in the charging device 1 is isolated, the carrier synchronization line and the power frequency synchronization line can be omitted from the parallel signal bus.

[0069] In one embodiment, the low-frequency circulating current control method of charging device 1 is as follows: After charging device 1 is in operation, each AC-DC converter module in charging device 1, if common-mode circulating current exists within itself, generates its own modulation wave based on its actual common-mode circulating current value to reduce its own common-mode circulating current. Because each AC-DC converter module in charging device 1 reduces its actual common-mode circulating current through this low-frequency circulating current control method, the low-frequency circulating current between the M second charging cabinets can be reduced, thereby improving the efficiency, EMC, and reliability of charging device 1.

[0070] In one embodiment, all AC-DC conversion modules in the charging device 1 are composed of the AC-DC conversion module 1M1g1 and other AC-DC conversion modules except the AC-DC conversion module 1M1g1, wherein the AC-DC conversion module 1M1g1 is the master module of the AC-DC conversion module in the charging device 1, and the other AC-DC conversion modules except the AC-DC conversion module 1M1g1 are slave modules of the AC-DC conversion module 1M1g1.

[0071] The high-frequency circulating current control method of charging device 1 is as follows: After charging device 1 is in operation, AC-DC conversion module 1M1g1 sends a control signal of AC-DC conversion module 1M1g1 to each of the other AC-DC conversion modules mentioned above via a carrier synchronization line. Each of the other AC-DC conversion modules mentioned above receives the control signal of AC-DC conversion module 1M1g1 via a carrier synchronization line and aligns its own control signal with the control signal of AC-DC conversion module 1M1g1 to achieve high-frequency circulating current control between different AC-DC conversion modules. Based on this high-frequency circulating current control method, the control signal of each of the other AC-DC conversion modules mentioned above can be aligned with the control signal of AC-DC conversion module 1M1g1, thereby reducing the high-frequency circulating current between the N second charging cabinets and improving the efficiency, EMC, and reliability of charging device 1.

[0072] In one embodiment, the proportional current sharing control method for each AC-DC conversion module in the charging device 1 is as follows: After the charging device 1 is in operation, each AC-DC conversion module in the charging device 1 obtains the rated power and actual output power of all other AC-DC conversion modules other than itself via the parallel communication line. Each AC-DC conversion module in the charging device 1 then determines the ratio of the actual total output power of all AC-DC conversion modules in the charging device 1 to the total rated power as a first ratio, thereby controlling its own output power to be the product of its own rated power and the first ratio, thereby achieving proportional current sharing control for each AC-DC conversion module. Furthermore, the output power of each AC-DC conversion module can be proportionally output based on its rated power, ensuring that AC-DC conversion modules with higher rated power output more power and AC-DC conversion modules with lower rated power output less power, thereby extending the service life of each AC-DC conversion module and improving the reliability of the charging device 1.

[0073] In addition, when the charging gun of the charging device 1 is connected to the charging vehicle, it controls the output power of the DC-DC conversion module connected to the charging vehicle through proportional distribution or on-demand distribution to ensure that the power input to the DC bus BUS of the charging device 1 when charging the charging vehicle is always greater than or equal to the power output from the DC bus BUS, thereby improving the reliability of the charging device 1.

[0074] In an optional embodiment, in response to the total rated power of all AC-DC conversion modules in the charging device 1 being less than or equal to the total charging power required by all charging vehicles connected to all charging guns in the charging device 1, the controller in each first charging cabinet controls the output power of one DC-DC conversion module corresponding to each first charging gun, or the total output power of multiple DC-DC conversion modules, to be equal to the product of the charging power required by the charging vehicle connected to each first charging gun and a power attenuation coefficient, wherein the first charging gun is a charging gun connected to a charging vehicle in each first charging cabinet. The power attenuation coefficient is greater than a preset threshold value and less than or equal to a second ratio, where the second ratio is the ratio of the total rated power of all AC-DC conversion modules to the total charging power required by all charging vehicles connected to the charging guns.

[0075] It is understood that when the total rated power of all AC-DC conversion modules in charging device 1 is less than or equal to the total charging power of all charging vehicles connected to the charging gun in charging device 1, by outputting a proportional portion of the required charging power to each charging vehicle connected to the charging gun, the situation where individual charging vehicles connected to the charging gun cannot be charged is avoided, thereby ensuring that each charging vehicle connected to the charging gun can be in a charging state, thereby improving the user's charging experience. In addition, by outputting a proportional portion of the required charging power to each charging vehicle connected to the charging gun, charging device 1 can ensure that the power input to the DC bus BUS of charging device 1 is always greater than or equal to the power output from the DC bus BUS when charging the charging vehicle, thereby also improving the reliability of charging device 1.

[0076] In another optional embodiment, the controller in each first charging cabinet controls the output power of a DC-DC conversion module corresponding to each first charging gun or the total output power of multiple DC-DC conversion modules to be the charging power required by the charging vehicle connected to each first charging gun in response to the total rated power of all AC-DC conversion modules in the charging device 1 being greater than the total charging power required by the charging vehicles connected to all charging guns in the charging device 1, wherein the first charging gun is the charging gun connected to the charging vehicle in each first charging cabinet.

[0077] It can be understood that when the total rated power of all AC-DC conversion modules in charging device 1 exceeds the total charging power of all vehicles connected to the charging guns of charging device 1, by outputting the required charging power to each connected vehicle, the charging efficiency of charging device 1 for each vehicle can be effectively improved, thereby enhancing the user's charging experience. In addition, when charging a vehicle, the power input to the DC bus of charging device 1 is always greater than or equal to the power output from the DC bus, which also improves the reliability of charging device 1.

[0078] Here, the specific implementation process of the low-frequency circulating current control method, high-frequency circulating current control method, proportional current sharing control method of each AC-DC conversion module, and controlling the output power of the DC-DC conversion module connected to the charging vehicle through proportional distribution or on-demand distribution of the charging device 1 is described in the corresponding part of the charging device 1 shown in Figure 3, and will not be repeated here.

[0079] In addition, the product of the total input power capacity of charging device 1 and the actual operating efficiency of charging device 1 is greater than or equal to the total output power of all charging guns in charging device 1, where the total input power capacity of charging device 1 is the minimum value of the sum of the maximum input power of each AC-DC conversion module in charging device 1 and the total rated power of the transformers connected to all AC-DC conversion modules in charging device 1. The controller in each second charging cabinet is also used to control the sum of the input power of all AC-DC conversion modules in its own cabinet to not exceed the rated power of the transformer connected to the second charging cabinet to which it is located, so as to ensure that the transformers connected to each second charging cabinet do not operate at excessive capacity, thereby improving the reliability of charging device 1.

[0080] In the embodiment of the present application, the charging device 1 pools the power capacity of the DC bus BUS by having all the AC-DC conversion modules in the M second charging cabinets and all the DC-DC conversion modules in the N first charging cabinets share the DC bus BUS. This allows the power on the DC bus BUS to be flexibly distributed as a whole in the form of the entire charging device when different second charging cabinets in the charging device 1 have different input power limits and / or different output powers. This not only meets the higher power level requirements of the charging device 1, but also maximizes the charging utilization rate of the charging device 1. In addition, the charging device 1 sets parallel communication lines between the various AC-DC conversion modules to achieve proportional current sharing control between the various first power conversion modes, thereby improving the efficiency of the charging device 1. When the circuit topology of each AC-DC converter module in charging device 1 is non-isolated, carrier synchronization lines or power frequency synchronization lines are provided between the modules to enable high-frequency carrier synchronization, power frequency phase detection and synchronization, and low-frequency circulating current control between the non-isolated AC-DC converter modules. This allows for circulating current control between the M second charging cabinets, reduces high- and low-frequency circulating currents between parallel units, and thereby improves the efficiency (reducing losses), EMC, and reliability of charging device 1. Furthermore, when charging a vehicle, the power input to the DC bus BUS of charging device 1 is always greater than or equal to the power output from the DC bus BUS, further improving the reliability of charging device 1.

[0081] It should be noted that in the above embodiment, a particular AC-DC conversion module in the charging device 1 obtains control signals, rated power, actual output power, or input voltage phase information of other AC-DC conversion modules other than itself via the parallel signal bus. In other words, the above data is obtained via wired communication. Alternatively, the above data can be obtained via wireless communication.

[0082] The above are only specific embodiments of the present application, but the scope of protection of this 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 device, characterized in that: The charging device includes a plurality of first charging cabinets, a plurality of AC-DC conversion modules, a DC bus and a plurality of charging guns, each of the plurality of first charging cabinets includes a group of DC-DC conversion modules, wherein: The input end of each AC-DC conversion module in the plurality of AC-DC conversion modules is used to connect to the output end of the transformer, and the output end of each AC-DC conversion module and the input end of each DC-DC conversion module in the group of DC-DC conversion modules are both connected to the DC bus; The output end of the group of DC-DC conversion modules is connected to a group of charging guns in the multiple groups of charging guns, and each group of charging guns in the multiple groups of charging guns is used to connect to a charging vehicle.

2. The charging device according to claim 1, characterized in that: The AC-DC conversion module is used to generate a modulation wave of the AC-DC conversion module based on an actual common-mode circulating current value of the AC-DC conversion module when a common-mode circulating current exists in the AC-DC conversion module, so as to reduce the common-mode circulating current of the AC-DC conversion module, wherein the modulation wave is used to control the switching tube in the AC-DC conversion module to be turned on or off.

3. The charging device according to claim 1 or 2, characterized in that: The plurality of AC-DC conversion modules include an AC-DC conversion module i; The AC-DC conversion module i is used to send a control signal of the AC-DC conversion module i to other AC-DC conversion modules among the multiple AC-DC conversion modules except the AC-DC conversion module i; Each of the other AC-DC conversion modules is used to receive the control signal of the AC-DC conversion module i, and control the control signal of each of the other AC-DC conversion modules to be aligned with the control signal of the AC-DC conversion module i.

4. The charging device according to any one of claims 1 to 3, characterized in that: The AC-DC conversion module is used to control the ratio of the output power of the AC-DC conversion module to the rated power to be a first ratio, wherein the first ratio is the ratio of the actual total output power of the multiple AC-DC conversion modules to the total rated power.

5. The charging device according to any one of claims 1 to 4, characterized in that: The product of the total input power capacity of the charging device and the actual operating efficiency of the charging device is greater than or equal to the total output power of the multiple groups of charging guns, wherein the total input power capacity of the charging device is the minimum value of the sum of the maximum input powers of the multiple AC-DC conversion modules and the total rated power of the transformers connected to the multiple AC-DC conversion modules, and the actual operating efficiency of the charging device is the ratio of the total output power of the multiple groups of charging guns to the total input power of the charging device.

6. The charging device according to any one of claims 3 to 5, characterized in that: The charging device also includes a parallel communication line, each of the AC-DC conversion modules is connected to the parallel communication line, and the parallel communication line is used to transmit the rated power or actual output power of any one of the multiple AC-DC conversion modules.

7. The charging device according to claim 6, characterized in that: The charging device also includes a carrier synchronization line or an industrial frequency synchronization line, each of the AC-DC conversion modules is connected to the carrier synchronization line or the industrial frequency synchronization line, the carrier synchronization line is used to transmit the control signal of the AC-DC conversion module i, and the industrial frequency synchronization line is used to transmit the input voltage phase information of any one of the AC-DC conversion modules.

8. The charging device according to any one of claims 1 to 7, characterized in that: The multiple AC-DC conversion modules include N groups of AC-DC conversion modules, the number of the multiple first charging cabinets is N, and each of the first charging cabinets also includes a group of AC-DC conversion modules.

9. The charging device according to any one of claims 1 to 7, characterized in that: The multiple AC-DC conversion modules include M groups of AC-DC conversion modules, and the charging device also includes the M second charging cabinets, each of the M second charging cabinets includes a group of AC-DC conversion modules.

10. The charging device according to claim 8 or 9, characterized in that: Each of the first charging cabinets further includes a controller, a group of charging guns connected to each of the first charging cabinets includes a plurality of charging guns, and a group of DC-DC conversion modules in each of the first charging cabinets includes a plurality of DC-DC conversion modules; The controller is used to control the output power of a DC-DC conversion module corresponding to each first charging gun or the total output power of multiple DC-DC conversion modules to be the product of the charging power required by the charging vehicle connected to each first charging gun and the power attenuation coefficient in response to the total rated power of the multiple AC-DC conversion modules being less than or equal to the total charging power required by the charging vehicles connected to the multiple groups of charging guns, wherein the first charging gun is a charging gun among the multiple charging guns that is connected to the charging vehicle, and the power attenuation coefficient is less than or equal to the ratio of the total rated power to the total charging power.

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