Charging System

Abstract

The present application provides a charging system, including a multi-pulse transformer, an AC-DC conversion unit, a power supply end, and a charging scheduling device, wherein the secondary winding of the multi-pulse transformer forms n winding pairs; the n AC-DC conversion units are connected to the n winding pairs in a one-to-one correspondence; the n power supply ends correspond to the n AC-DC conversion units in a one-to-one correspondence, and each power supply end is electrically connected to the output end of the corresponding AC-DC conversion unit; the charging scheduling device is used to detect the number of charging devices and the state of the power supply end, and determine M target winding pairs for supplying power to the charging devices from the n winding pairs, wherein the M target winding pairs include a winding pair distributed near the first end of the magnetic core and a winding pair distributed near the second end of the magnetic core, thereby reducing the winding loss generated by the leakage magnetic flux of the primary winding on the winding, and also reducing the eddy current loss of the leakage magnetic flux in the surrounding metal, thereby reducing the loss of the multi-pulse transformer.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a charging system. Background Art

[0002] With the development of electric vehicles, a large number of charging stations need to be built. Reducing charging losses is one of the design goals of the charging system in the charging station, and the leakage flux of the winding on the transformer in the charging system will cause losses.

[0003] In the prior art, the influence of leakage flux is reduced by modifying the structure of the transformer itself. However, it is difficult to change the structure of the transformer in the prior art, which increases the complexity of the transformer structure, and the structural change may also bring about changes in the transformer characteristics. Summary of the invention

[0004] The embodiment of the present application provides a charging system, which reduces the electromagnetic loss of a multi-pulse transformer.

[0005] According to a first aspect of an embodiment of the present application, a charging system is provided, including:

[0006] A multi-pulse transformer, comprising a primary winding, a magnetic core and a plurality of secondary windings, wherein the plurality of secondary windings form n winding pairs;

[0007] n AC-DC conversion units, corresponding one to one with the n winding pairs, and an input end of each AC-DC conversion unit is electrically connected to a corresponding winding pair;

[0008] n power supply terminals, corresponding one to one with the n AC-DC conversion units, each of the power supply terminals being electrically connected to an output terminal of a corresponding AC-DC conversion unit; and

[0009] A charging scheduling device is used to detect the number M of charging devices and the state of the power supply end, and determine M target winding pairs for powering the charging devices from the n winding pairs, wherein the M target winding pairs include the winding pairs distributed near the first end of the magnetic core and the winding pairs distributed near the second end of the magnetic core.

[0010] Optionally, the n winding pairs are distributed sequentially along the center line of the magnetic core;

[0011] The target winding pairs for supplying power to the charging device include at least the i-th winding pair and the ni-th winding pair, where 3≧i≧1, and n>3.

[0012] Optionally, the n winding pairs are distributed sequentially along the center line of the magnetic core;

[0013] The charging scheduling device is specifically used for:

[0014] If it is determined that M is 2, two winding pairs sequentially distributed at both ends of the n winding pairs are determined as target winding pairs;

[0015] If it is determined that M is greater than 2, two winding pairs sequentially distributed at both ends of the n winding pairs and M-2 winding pairs distributed between the two winding pairs are determined as target winding pairs.

[0016] Optionally, the M-2 target winding pairs distributed between the two winding pairs are evenly distributed.

[0017] Optionally, the charging scheduling device is specifically used to set the target winding pair for powering n / 2 charging devices as an interval-distributed winding pair with an interval of 1 winding pair if it is determined that M is greater than n / 2.

[0018] According to a second aspect of an embodiment of the present application, a charging system is provided, comprising: a multi-pulse transformer, n power supply devices, and a charging scheduling device;

[0019] The multi-pulse transformer comprises: a primary winding, a magnetic core and a plurality of secondary windings, wherein the plurality of secondary windings form 2n winding pairs;

[0020] Each of the power supply devices corresponds to two winding pairs, and the power supply device includes: a first AC-DC conversion unit and a second AC-DC conversion unit; wherein the input end of the first AC-DC conversion unit is electrically connected to one of the two winding pairs, and the output end of the first AC-DC conversion unit is a first power supply end; the input end of the second AC-DC conversion unit is electrically connected to the other of the two winding pairs, and the output end of the second AC-DC conversion unit is a second power supply end;

[0021] The charging scheduling device is used to detect the number M of charging devices and the status of the power supply end, and determine the target winding pair for powering the charging device among the 2n winding pairs, wherein the multiple target winding pairs include the winding pair distributed near the first end of the magnetic core and the winding pair distributed near the second end of the magnetic core.

[0022] Optionally, the winding pair connected to the first AC-DC conversion unit includes a first winding and a second winding, and the winding pair connected to the second AC-DC conversion unit includes a third winding and a fourth winding; the phases of the output voltages of the first winding, the third winding, the second winding, and the fourth winding are shifted left or right by 15° respectively.

[0023] Optionally, the 2n winding pairs are distributed sequentially along the center line of the magnetic core.

[0024] Optionally, the charging scheduling device is specifically used for:

[0025] If M is determined to be 3, two winding pairs sequentially distributed at both ends of the 2n winding pairs and an adjacent winding pair of one of the two winding pairs are determined as target winding pairs, wherein the adjacent winding pair and one of the two winding pairs correspond to the same power supply device.

[0026] Optionally, the charging scheduling device is specifically used for:

[0027] If it is determined that M is greater than or equal to 4, the two winding pairs distributed at the first end of the magnetic core and the two winding pairs distributed at the second end of the magnetic core are used as the four target winding pairs for powering four of the charging devices, wherein the two winding pairs distributed at the first end of the magnetic core both correspond to one power supply device, and the two winding pairs distributed at the second end of the magnetic core both correspond to another power supply device.

[0028] Optionally, the charging scheduling device is specifically used for:

[0029] If it is determined that M is greater than 4, then the remaining M-4 target winding pairs are determined among the winding pairs between the two winding pairs distributed at the first end of the magnetic core and the two winding pairs distributed at the second end of the magnetic core.

[0030] Optionally, M is an even number, and the remaining M-4 target winding pairs are electrically connected to M / 2-2 power supply devices.

[0031] Optionally, the two winding pairs distributed at the first end of the magnetic core and the M-4 target winding pairs distributed between the two windings at the second end of the magnetic core are evenly distributed.

[0032] The present application provides a charging system in which M target winding pairs include the winding pair distributed near the first end of the magnetic core and the winding pair distributed near the second end of the magnetic core, so that the magnetic field range of the target winding on the magnetic core is close to the magnetic field range of the primary winding on the magnetic core, thereby reducing the winding loss generated by the leakage magnetic flux of the primary winding on the winding, and also reducing the eddy current loss of the leakage magnetic flux in the surrounding metal, thereby reducing the loss of the multi-pulse transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of an application scenario of an embodiment of the present application;

[0034] Figure 2 It is a schematic diagram of a charging system structure provided in an embodiment of the present application;

[0035] Figure 3a It is an existing reference example of target winding pair distribution;

[0036] Figure 3bis an example of target winding pair distribution provided in an embodiment of the present application;

[0037] Figure 4 is a target winding pair scheduling example provided in an embodiment of the present application;

[0038] Figure 5 is another schematic diagram of the charging system structure provided in an embodiment of the present application;

[0039] Figure 6 The embodiment of this application provides Figure 5 An example of a target winding pair distribution for the structure shown;

[0040] Figure 7 The embodiment of this application provides Figure 5 Another example of target winding pair distribution for the structure shown;

[0041] Figure 8 This is a schematic diagram of the structure of a first AC-DC conversion unit provided in an embodiment of the present application;

[0042] Fig. 9 is another schematic diagram of the structure of a first AC-DC conversion unit provided in an embodiment of the present application;

[0043] Fig.10 This is a schematic diagram of the structure of another first AC-DC conversion unit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0045] The terms "first", "second", "third", "fourth", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0046] It should be understood that in the various embodiments of the present application, the size of the serial number of each process does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0047] It should be understood that in the present application, "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0048] It should be understood that, in the present application, “plurality” means two or more than two.

[0049] It should be understood that the term “connection” herein includes any direct and indirect electrical connection means. Therefore, if the text describes a first element as being connected to a second element, it means that the first element can be directly electrically connected to the second element, or indirectly electrically connected to the second element through other elements or connection means.

[0050] It should be understood that in this application, "B corresponding to A", "B corresponding to A", "A corresponds to B" or "B corresponds to A" means that B is associated with A and B can be determined based on A. Determining B based on A does not mean determining B based only on A, but B can also be determined based on A and / or other information. A and B match when the similarity between A and B is greater than or equal to a preset threshold.

[0051] Depending on the context, "if" as used herein may be interpreted as "when" or "when" or "in response to determining" or "in response to detecting."

[0052] The technical solution of the present application is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0053] In order to solve the technical problem of high transformer loss in the existing charging system, the present application provides a charging system, which reduces the winding loss generated by the leakage flux of the primary winding on the winding, and also reduces the eddy current loss of the leakage flux in the surrounding metal, thereby reducing the loss of the multi-pulse transformer. The various optional structures of the charging system provided by the present application are illustrated below in combination with the accompanying drawings and specific embodiments.

[0054] See also Figure 1 , is a schematic diagram of an application scenario of an embodiment of the present application. Figure 1In the scenario shown, the charging system is, for example, installed in a charging station, and the charging device can be, for example, an electric car that needs to be charged. M electric vehicles are connected to the charging system of the charging station for charging. In the prior art, electric vehicles are randomly connected to idle power supply terminals, with some power supply terminals working and other power supply terminals idle. The transformer in the charging system generates a large leakage flux, which results in large winding losses on the windings and large eddy current losses on the metal casing where the transformer is installed. If the influence of the leakage flux is reduced by modifying the structure of the transformer itself, the design difficulty and structural complexity of the transformer are increased, and the structural changes may also bring about changes in the characteristics of the transformer, and the reliability is not high enough. In order to reduce the losses generated when the transformer is not working at full load, it can be done in the following ways: Figure 1 In the scenario shown, the charging system provided by the embodiment of the present application is applied to reduce the leakage flux coupling effect between the windings by scheduling the distribution of the secondary windings in the working state, thereby reducing the leakage flux and thus reducing the loss caused by the leakage flux.

[0055] See also Figure 2 , is a schematic diagram of the structure of a charging system provided in an embodiment of the present application. Figure 2 The charging system 10 shown includes: a multi-pulse transformer 11, AC-DC conversion units (1, ..., n), power supply terminals (D1, ..., Dn) and a charging scheduling device (not shown in the figure).

[0056] The multi-pulse transformer 11 includes a primary winding 111, a magnetic core 112 and a plurality of secondary windings 113, wherein the plurality of secondary windings 113 form n winding pairs. In this embodiment, the number of secondary windings 113 in the multi-pulse transformer is an even number, and the secondary windings 113 form n winding pairs in pairs. Figure 2 The multi-pulse transformer 11 shown can be a 24-pulse transformer, a 36-pulse transformer, a 48-pulse transformer, a 64-pulse transformer or a 72-pulse transformer, which is not limited here. Further, the difference in phase shift angles between the two secondary windings in each winding pair is 30°.

[0057] Continue to see Figure 2, n AC-DC conversion units (1, ..., n) correspond one-to-one to n winding pairs, and the input end of each AC-DC conversion unit is electrically connected to the corresponding winding pair. And n power supply ends (D1, ..., Dn) correspond one-to-one to n AC-DC conversion units, and each power supply end is electrically connected to the output end of the corresponding AC-DC conversion unit. The power supply end may be, for example, a power supply interface electrically connected to a charging pile. In some embodiments, the power supply end may be fixedly electrically connected to the charging pile in a one-to-one correspondence, and the charging scheduling device may realize distributed control of the power supply end in a working state by scheduling the charging pile to which the charging device is connected. In other embodiments, the power supply end may be selectively electrically connected to the charging pile, and the charging scheduling device may realize distributed control of the power supply end in a working state by selecting which power supply ends are electrically connected to the charging pile to which the charging device is connected.

[0058] The charging scheduling device in this embodiment is used to detect the number M of charging devices and the status of the power supply end, and determine M target winding pairs for powering the M charging devices from the n winding pairs, wherein the M target winding pairs include a winding pair distributed near the first end of the magnetic core and a winding pair distributed near the second end of the magnetic core.

[0059] It should be understood that among the n winding pairs, the winding pair electrically connected to the power supply end for charging the charging device is the target winding pair in this embodiment. When the number of charging devices M is less than the number of winding pairs n, the power supply end corresponding to some secondary windings 113 is not connected to the charging device and is in an idle state. The primary winding 111 corresponding to the idle secondary winding 113 generates a large leakage flux. In order to reduce the loss generated by these leakage fluxes, the charging scheduling device in this embodiment selects multiple winding pairs from the n winding pairs according to the number of charging devices M and the state of each power supply end as the target winding pair for powering the charging device. When selecting the target winding pair, the charging scheduling device of this embodiment includes the winding pairs distributed near the two ends of the magnetic core into the target winding pair, so that the distribution range of the target winding pair is close to the distribution range of the primary winding 111, and then the magnetic field formed by the target winding pair in the working state is further offset by the magnetic field formed by the primary winding, reducing the loss caused by the leakage flux to the multi-pulse transformer and the impact on the metal shell of the transformer.

[0060] A charging system provided in this embodiment includes a multi-pulse transformer, an AC-DC conversion unit, a power supply end, and a charging scheduling device, wherein the multi-pulse transformer includes a primary winding, a magnetic core, and a plurality of secondary windings, wherein the plurality of secondary windings form n winding pairs; n AC-DC conversion units correspond one-to-one to the n winding pairs, and the input end of each AC-DC conversion unit is electrically connected to the corresponding winding pair; n power supply ends correspond one-to-one to the n AC-DC conversion units, and each power supply end is electrically connected to the output end of the corresponding AC-DC conversion unit A charging scheduling device, used for detecting the number M of charging devices and the state of the power supply end, and determining M target winding pairs for supplying power to the charging devices from the n winding pairs, wherein the M target winding pairs include the winding pairs distributed near the first end of the magnetic core and the winding pairs distributed near the second end of the magnetic core, so as to achieve a magnetic field range of the target winding on the magnetic core close to the magnetic field range of the primary winding on the magnetic core, reduce the winding loss generated by the leakage magnetic flux of the primary winding on the winding, and also reduce the eddy current loss of the leakage magnetic flux in the surrounding metal, thereby reducing the loss of the multi-pulse transformer.

[0061] See also Figure 3a , is an existing reference example of target winding pair distribution. Figure 3a In the prior art example shown, the primary winding and the secondary winding are concentrically wound on the magnetic core. Figure 3a When electric vehicles are connected to the power supply end in sequence, winding pairs are connected to the multi-pulse transformer in sequence, resulting in the target winding pairs used to charge the electric vehicles being concentrated at one end close to the magnetic core, while the other end of the magnetic core is all idle winding pairs. Figure 3a The secondary winding magnetic field of the multi-pulse transformer shown is concentrated on the upper part of the magnetic core. Assuming that there are 12 electric vehicles that need to be charged, the number of winding pairs is 24. Figure 3a In the example shown, the 12 vehicles are connected to the 12 power supply terminals ( Figure 3a See Table 1 for a comparison of two sets of loss magnetic field simulation data of this application. Figure 3a In a set of loss magnetic field simulation data, if the influence of leakage flux is not considered, the total loss of the primary side is 886W, the total loss of the secondary side is 996W, that is, the total loss of the multi-pulse transformer is 1882W. If the influence of leakage flux is considered, the total loss of the primary side of the multi-pulse transformer is 1054W, the total loss of the secondary side is 1310W, that is, the total loss of the multi-pulse transformer is 2366.2W. In addition, the single-side loss of the metal shell of the multi-pulse transformer is 646W.

[0062] See also Figure 3b , is an example of target winding pair distribution provided in an embodiment of the present application. Figure 3bIn an optional embodiment shown, the primary winding and the secondary winding are concentrically wound on the magnetic core. Figure 3b When electric vehicles are connected to the power supply end in sequence, the winding pairs formed by the secondary windings of the multi-pulse transformer are scheduled by the charging scheduling device, and the winding pairs close to the first end of the magnetic core and the winding pairs close to the second end of the magnetic core are both used as target winding pairs, and winding pairs are evenly selected between the two ends as target winding pairs. Figure 3b In the example shown, the target winding pairs are spaced apart in the distribution range of the winding pairs, and the projection of the distribution range of the target winding on the magnetic core is close to the projection of the distribution range of the primary winding on the magnetic core. Figure 3b The secondary winding magnetic field of the multi-pulse transformer is evenly distributed over the entire core. Assume that there are 12 electric vehicles that need to be charged, and the number of winding pairs is 24. Figure 3b In the example shown, the 12 vehicles are connected to the 12 power supply terminals distributed in the winding pairs No. 1, No. 3, No. 5, No. 7, No. 9, No. 11, No. 13, No. 15, No. 17, No. 19, No. 21, and No. 23 ( Figure 3b ), continue to refer to Table 1, Figure 3b In a set of loss magnetic field simulation data, if the influence of leakage flux is not considered, the total loss of the multi-pulse transformer is 1885W. If the influence of leakage flux is considered, the total loss of the multi-pulse transformer is 1925.7W. In addition, the single-side loss of the metal shell of the multi-pulse transformer is 4W.

[0063] Continue to refer to the comparison in Table 1. Figure 3b The target winding pair distribution shown is relative to Figure 3a The target winding pair distribution shown reduces the total transformer loss by 440.5W considering the leakage flux, and reduces the single-side loss of the metal casing by 642W, achieving better loss reduction effect.

[0064] Table 1

[0065]

[0066] exist Figure 2 , Figure 3a and Figure 3b In the multi-pulse transformer structure shown, n winding pairs are sequentially distributed along the center line of the magnetic core. The winding pairs distributed near the two ends of the magnetic core can be, for example, one of the first i winding pairs at the beginning of the sequence and one of the last i winding pairs at the end of the sequence. The value of i can be any value from 1 to 4.

[0067] In some embodiments, the winding pair distributed near the first end of the magnetic core as the target winding pair can correspond to any one of the three winding pairs in positive sequence; and the winding pair distributed near the second end of the magnetic core can also include any one corresponding to the third winding pair in reverse sequence.

[0068] In some embodiments, the charging scheduling device is specifically used to include the i-th winding pair and the ni-th winding pair in sequence as the target winding pair for powering the charging device, where 3≧i≧1, n>3. Figure 3a or Figure 3b In the example, if winding pair 1 is used as the target winding pair, winding pair 23 is also used as the target winding pair. Figure 3a or Figure 3b In the example, if winding pair 2 is used as the target winding pair, winding pair 22 is also used as the target winding pair. Figure 3a or Figure 3b The 3rd winding pair is taken as the target winding pair, and the 21st winding pair is also taken as the target winding pair. The i-th winding pair is the winding pair distributed near the first end of the magnetic core, and the ni-th winding pair is the winding pair distributed near the second end of the magnetic core. However, the present invention is not limited to this. For example, Figure 3a or Figure 3b For example, if winding pair 1 is used as the target winding pair, winding pair 24 or 22 is also used as the target winding pair. Figure 3a or Figure 3b If winding pair 2 is used as the target winding pair, then winding pair 24 or 23 is also used as the target winding pair. Figure 3a or Figure 3b If winding pair No. 3 is taken as the target winding pair, then winding pair No. 24, 23 or 22 is also taken as the target winding pair; as long as the multiple target winding pairs include winding pairs distributed near the first end and winding pairs near the second end, they should all fall within the protection scope of the present invention.

[0069] The n winding pairs are distributed in sequence along the center line of the magnetic core. Figure 2 , Figure 3a and Figure 3b In the multi-pulse transformer structure shown, the winding pairs distributed at the start position and the end position are closer to the two ends of the magnetic core. In some embodiments, M is greater than or equal to 2, and the charging scheduling device is specifically used for:

[0070] If M is determined to be 2, then two winding pairs sequentially distributed at both ends of the n winding pairs are determined as target winding pairs; for example Figure 3b The winding pair No. 1 and the winding pair No. 24 in.

[0071] If it is determined that M is greater than 2, two winding pairs sequentially distributed at both ends of the n winding pairs and M-2 winding pairs distributed between the two winding pairs are determined as target winding pairs.

[0072] It can be understood that when it is detected that only two charging devices need to be charged, the charging scheduling device schedules the power supply ends corresponding to the winding pairs across the two ends of the magnetic core to be connected to the two charging devices for power supply, that is, the first winding pair and the last winding pair in sequence can be used as the target winding pairs. When more than two charging devices are detected, in addition to scheduling the two power supply ends corresponding to the winding pairs across the two ends of the magnetic core to be connected to the charging devices for power supply, the charging scheduling device also selects and schedules the remaining M-2 winding pairs from the winding pairs distributed between the winding pairs across the two ends of the magnetic core, and schedules the M-2 power supply ends corresponding to the M-2 winding pairs to be connected to the charging devices for power supply. Therefore, the distribution of the target winding pairs in working state on the center line of the magnetic core is at the two ends of the magnetic core and between the two ends. Regardless of the scheduling scheme when M is 2 or when M is greater than 2, the first winding pair and the last winding pair in sequence are used as the target winding pair, and the distribution range of the target winding pair along the magnetic core is determined from the first winding pair in sequence to the last winding pair in sequence. The distribution range of the target winding pair along the magnetic core, the distribution range of the primary winding pair along the magnetic core, and the distribution range of the secondary winding pair along the magnetic core are all consistent. The consistency of the distribution range allows the magnetic field of the primary winding to overlap with the magnetic field of the target winding, reducing the loss of the multi-pulse transformer, reducing the influence of the leakage flux, and reducing the additional loss of the metal shell of the transformer. It should be noted that the first winding pair and the last winding pair in sequence here are not the first and last in the strict sense, as long as they are close to the first end (or the front end) and close to the second end (or the last end), they meet the requirements.

[0073] In some embodiments, in the above embodiment where M is greater than 2, the M-2 target winding pairs selected by the charging scheduling device and distributed between the two winding pairs are uniformly distributed winding pairs. The uniform distribution here can be understood as the number of winding pairs between two adjacent target winding pairs differing by 1, 2 or 0, which can minimize the leakage flux, thereby minimizing the loss effect caused by the leakage flux.

[0074] On the basis of the various embodiments described above, in some of the embodiments, the charging scheduling device is further used to set the target winding pairs that power n / 2 charging devices as interval-distributed winding pairs if it is determined that M is greater than n / 2, and the interval is 1 winding pair. It can be understood that if the charging scheduling device detects that the number of charging devices M is greater than half of the number of power supply terminals, it cannot be guaranteed that the number of winding pairs between two adjacent target winding pairs is exactly the same, so the n / 2 target winding pairs are first determined to be distributed as intervals of a single winding pair, and then the remaining Mn / 2 target winding pairs are selected from the interval winding pairs. Optionally, the charging scheduling device can select the remaining Mn / 2 target winding pairs from the interval winding pairs in a uniform selection manner, for example, the remaining Mn / 2 target winding pairs are uniformly distributed in the interval winding pairs.

[0075] In actual applications, the number of charging devices is not fixed. As electric vehicles are continuously connected or disconnected, the number M changes. The charging scheduling device schedules the target winding pair and its corresponding power supply end according to the currently detected M. For example, the charging scheduling device is specifically used to obtain the number M of charging devices when determining to connect a new charging device, based on the number of charging devices that have been connected for charging plus the number of charging devices that are about to be connected. Of course, the number M of charging devices can also only include the number of charging devices that need to be connected, that is, the target winding pair and power supply end are scheduled for the device to be charged, and the original charging device no longer participates in the scheduling.

[0076] See also Figure 4 , is an example of target winding pair scheduling provided in an embodiment of the present application. Figure 4 As shown in the figure, the symbol "#" represents the winding pair number selected as the target winding pair.

[0077] like Figure 4 As shown, when it is detected that the number of charging devices M is 2, the charging scheduling device uses winding pairs No. 1 and No. 23 as target winding pairs to charge the current two charging devices.

[0078] like Figure 4 As shown, when it is detected that the number of charging devices M is 4, the charging scheduling device uses winding pairs 1, 9, 17 and 23 as target winding pairs to charge the current 4 charging devices. In some embodiments, the number of charging devices 4 is the original 2 charging devices plus the newly connected 2 charging devices; in other embodiments, the number of charging devices 4 corresponds to the newly connected 4 charging devices.

[0079] like Figure 4As shown, when it is detected that the number of charging devices M is 7, the charging scheduling device uses winding pairs 1, 5, 9, 13, 17, 21 and 23 as target winding pairs to charge the current 7 charging devices. In some embodiments, the number of charging devices 7 is the original 4 charging devices plus the newly connected 3 charging devices; in other embodiments, the number of charging devices 7 corresponds to the newly connected 7 charging devices.

[0080] like Figure 4 As shown in the figure, when the number of charging devices M is detected to be 12, the charging scheduling device uses winding pairs No. 1, No. 3, No. 5, No. 7, No. 9, No. 11, No. 13, No. 15, No. 17, No. 19, No. 21 and No. 23 as target winding pairs to charge the current 12 charging devices. It can be seen that when M is n / 2, the target winding pairs scheduled by the charging scheduling device can achieve strict uniform distribution, that is, the number of winding pairs between two adjacent target winding pairs is the same, for example, the number of winding pairs between two adjacent target winding pairs is 1.

[0081] like Figure 4 As shown in the figure, when the number of charging devices M is detected to be 14, the charging scheduling device uses winding pairs No. 1, No. 2, No. 3, No. 5, No. 7, No. 9, No. 11, No. 13, No. 15, No. 17, No. 19, No. 21, No. 23 and No. 24 as target winding pairs to charge the current 14 charging devices. For example, winding pairs No. 1, No. 3, No. 5, No. 7, No. 9, No. 11, No. 13, No. 15, No. 17, No. 19, No. 21 and No. 23 are selected as target winding pairs to charge 12 of the charging devices, and winding pairs No. 2 and No. 24 are selected as target winding pairs to power the remaining 2 charging devices. It can be seen that when M is greater than n / 2, n / 2 target winding pairs with strict uniform distribution can be determined first, and then the remaining Mn / 2 target winding pairs can be selected symmetrically.

[0082] like Figure 4 As shown, when it is detected that the number of charging devices M is 16, the charging scheduling device takes winding pairs No. 1, 2, 3, 4, 5, 7, 9, 11, 13, 15, 17, 19, 21, 22, 23 and 24 as target winding pairs to charge the current 16 charging devices.

[0083] Figure 4 The embodiment shown is an optional implementation method for the charging scheduling device to evenly select winding pairs, but the present application is not limited thereto. Figure 4 In the embodiment shown, after determining that winding pairs No. 1 and No. 23 (or No. 24) are target winding pairs, winding pairs can be randomly selected from winding pairs No. 2 to No. 22 in sequence as the remaining target winding pairs, and both can be relative to Figure 3aThe prior art shown reduces the losses of the multi-pulse transformer.

[0084] In the above embodiment, when the charging scheduling device detects that a charging device has finished charging using a connected power supply end, it can also preferentially transfer the connected power supply end to a new device to be charged for charging, so as to maintain the original target winding pair distribution. The specific transfer method can be to schedule the new device to be charged to charge on the charging pile used by other charging devices that have finished charging, or to switch the connected power supply end to the charging pile where the new device to be charged is located by switching a switch. The specific transfer method is not limited here.

[0085] This application also provides another charging system. Figure 5 , is another schematic diagram of the charging system structure provided by the embodiment of the present application. Figure 5 The charging system 20 shown includes: a multi-pulse transformer 21, n power supply devices (Y1, ..., Yn) and a charging scheduling device (not shown in the figure).

[0086] The multi-pulse transformer 21 includes: a primary winding 211 , a magnetic core 212 and a plurality of secondary windings 213 , wherein the plurality of secondary windings 213 form 2n winding pairs.

[0087] Each power supply device (Y1, ..., Yn) corresponds to 2 winding pairs. Figure 5 The power supply device (Y1, ..., Yn) comprises: a first AC-DC conversion unit and a second AC-DC conversion unit. The input end of the first AC-DC conversion unit is electrically connected to one of the two winding pairs, and the output end of the first AC-DC conversion unit is a first power supply end (D11, ..., Dn1); the input end of the second AC-DC conversion unit is electrically connected to the other of the two winding pairs, and the output end of the second AC-DC conversion unit is a second power supply end (D12, ..., Dn2).

[0088] The charging scheduling device is used to detect the number M of charging devices and the status of the power supply end, and determine the target winding pair for powering the charging device among 2n winding pairs, wherein the multiple target winding pairs include the winding pair distributed near the first end of the magnetic core and the winding pair distributed near the second end of the magnetic core.

[0089] Figure 5 The charging system 20 shown is Figure 2 The charging system 10 shown is similar in structure except that Figure 5 In the charging system 20 shown, two adjacent AC-DC conversion units form a power supply device.

[0090] A charging system provided in this embodiment includes a multi-pulse transformer, n power supply devices and a charging scheduling device; wherein the multi-pulse transformer includes: a primary winding, a magnetic core and a plurality of secondary windings, wherein the plurality of secondary windings form 2n winding pairs; each of the power supply devices corresponds to two winding pairs, and the power supply device includes: a first AC-DC conversion unit and a second AC-DC conversion unit; wherein the input end of the first AC-DC conversion unit is electrically connected to one of the two winding pairs, and the output end of the first AC-DC conversion unit is a first power supply end; the input end of the second AC-DC conversion unit is electrically connected to the two winding pairs. another winding pair in the middle, the output end of the second AC-DC conversion unit is the second power supply end; the charging scheduling device is used to detect the number M of charging devices and the state of the power supply end, and determine the target winding pair for powering the charging device from the 2n winding pairs, wherein the multiple target winding pairs include the winding pair distributed near the first end of the magnetic core and the winding pair distributed near the second end of the magnetic core, so as to achieve a magnetic field range of the target winding on the magnetic core close to the magnetic field range of the primary winding on the magnetic core, reduce the winding loss generated by the leakage magnetic flux of the primary winding on the winding, and also reduce the eddy current loss of the leakage magnetic flux in the surrounding metal, thereby reducing the loss of the multi-pulse transformer.

[0091] In some embodiments, when both power supply terminals of a single power supply device are connected to a charging device for charging, 24-pulse charging is formed, thereby reducing transformer losses and system harmonics. Figure 5 In each power supply device shown, the winding pair connected to the first AC-DC conversion unit includes a first winding and a second winding, and the winding pair connected to the second AC-DC conversion unit includes a third winding and a fourth winding. The phases of the output voltages of the first winding, the third winding, the second winding, and the fourth winding are shifted to the left or right by 15° in sequence, so that 24 pulses can be formed when the first power supply terminal and the second power supply terminal of the same power supply device are simultaneously connected to the charging device for charging.

[0092] exist Figure 5 In the illustrated embodiment, 2n winding pairs are sequentially distributed along the center line of the magnetic core.

[0093] In some embodiments, the charging scheduling device is specifically configured to determine, if M is determined to be 2, two winding pairs sequentially distributed at both ends of the 2n winding pairs as target winding pairs; for example Figure 5 The uppermost winding pair 213 and the lowermost winding pair 213 are determined as the target winding pair. At this time, the power supply device Y1 and the power supply device Yn form a 12-pulse rectification charging and cannot form a 24-pulse.

[0094] If M is determined to be 3, two winding pairs sequentially distributed at both ends of the 2n winding pairs and an adjacent winding pair of one of the two winding pairs are determined as target winding pairs, wherein the adjacent winding pair and one of the two winding pairs correspond to the same power supply device, and the power supply device forms 24-pulse rectified charging.

[0095] See also Figure 6 , is provided in the embodiment of the present application Figure 5 An example of a target winding pair distribution for the structure shown. Figure 6 As shown, the number M of charging devices is equal to 3, and the charging scheduling device needs to determine 3 target winding pairs among 2n winding pairs. Figure 6 The charging scheduling device takes the first winding pair (No. 1) and the last winding pair (No. 2n) in the sequence as the target winding pair, and also takes the second winding pair (No. 2) in the sequence as the target winding pair. The first winding pair (No. 1) and the second winding pair (No. 2) in the sequence both correspond to the same power supply device Y1. This embodiment is not limited to this. In another implementation, the charging scheduling device may also take Figure 6 The first winding pair (No. 1) and the last winding pair (No. 2n) in the sequence are taken as the target winding pair, and the second winding pair (No. 2n-1) in the reverse sequence is taken as the target winding pair. Among them, the last winding pair (No. 2n) and the second winding pair (No. 2n-1) in the reverse sequence correspond to the same power supply device Yn. Therefore, while reducing the influence of leakage flux and the loss of multi-pulse transformer, 24-pulse charging can be achieved, harmonic pollution can be reduced, and power supply quality can be improved.

[0096] For the implementation method of determining M to be 2 in this embodiment, see Figure 2 Among the various embodiments shown, the embodiment in which M is detected to be equal to 2 has similar principles and technical effects, which will not be elaborated here.

[0097] In some embodiments, the charging scheduling device is specifically used to: if it is determined that M is greater than or equal to 4, then the two winding pairs distributed at the first end of the magnetic core and the two winding pairs distributed at the second end of the magnetic core are used as four target winding pairs for powering four charging devices, wherein the two winding pairs distributed at the first end of the magnetic core both correspond to one power supply device, and the two winding pairs distributed at the second end of the magnetic core both correspond to another power supply device. It should be understood that when the number of charging devices is 4 or greater than 4, at least 4 target winding pairs can form two 24-pulse charging power supplies. The first power supply device in sequence is used as a charging power supply for 24-pulse charging, and the last power supply device in sequence is used as another charging power supply for 24-pulse charging. In this way, while reducing the loss of the multi-pulse transformer, the charging device can be used to the maximum extent to form 24-pulse charging, thereby reducing the harmonics generated by the charging system.

[0098] In some embodiments, for the case where M is greater than 4, based on the above embodiment of determining the four target windings corresponding to the two power supply devices, the charging scheduling device is also used to determine the remaining M-4 target winding pairs in the winding pairs between the two winding pairs distributed at the first end of the magnetic core and the two windings distributed at the second end of the magnetic core if it is determined that M is greater than 4. Wherein, if M is an even number, that is, a multiple of 2, the remaining M-4 target winding pairs determined by the charging scheduling device are electrically connected to M / 2-2 power supply devices. It should be understood that if M is an even number, then M-4 is also a multiple of 2, that is, at least one power supply device (that is, M / 2-2) can be used to charge the remaining M-4 charging devices. For example, if the number of charging devices M is 12, and the number of winding pairs 2n is 24, then after determining the four target winding pairs located at both ends of the magnetic core, it is necessary to determine 8 target winding pairs. The eight target winding pairs can be four power supply devices selected from the ten power supply devices located between the first power supply device in the sequence and the last power supply device in the sequence, and the eight winding pairs corresponding to the four power supply devices are used as the remaining eight target winding pairs.

[0099] Based on the above embodiment, the two winding pairs distributed at the first end of the magnetic core and the M-4 target winding pairs distributed between the two windings at the second end of the magnetic core selected by the charging scheduling device can be evenly distributed. The even distribution here can be understood as the number of winding pairs between two adjacent target winding pairs differing by 1, 2 or 0.

[0100] In some embodiments, the winding pair distributed near the first end of the magnetic core as the target winding pair can correspond to any one of the three winding pairs in positive sequence; and the winding pair distributed near the second end of the magnetic core can also correspond to any one of the three winding pairs in reverse sequence.

[0101] See also Figure 7 , is provided in the embodiment of the present application Figure 5 Another example of target winding pair distribution for the structure shown. Figure 7 In the structure shown, the number M of charging devices is 12, and the number 2n of winding pairs is 24, which correspond to 12 power supply devices (not shown in the figure) in turn. Figure 7 The 12 target winding pairs in are winding pairs No. 1, No. 2, No. 5, No. 6, No. 9, No. 10, No. 13, No. 14, No. 17, No. 18, No. 21, and No. 22 ( Figure 7). Among them, winding pairs 1 and 2 correspond to the same power supply device; winding pairs 5 and 6 correspond to the same power supply device; winding pairs 9 and 10 correspond to the same power supply device; winding pairs 13 and 14 correspond to the same power supply device; winding pairs 17 and 18 correspond to the same power supply device; winding pairs 21 and 22 correspond to the same power supply device. Thus, 6 power supply devices are used to charge the charging equipment, and a 24-pulse rectification charging system is performed, which reduces the system harmonics while reducing the transformer loss.

[0102] exist Figure 5 In some embodiments of the structure shown, the winding pair connected to the first AC-DC conversion unit includes a first winding and a second winding, and the winding pair connected to the second AC-DC conversion unit includes a third winding and a fourth winding. The first winding and the second winding obtain electric energy from the grid side through the multi-pulse transformer, and input it into the first AC-DC conversion unit for AC-DC conversion. The DC power output by the first AC-DC conversion unit after the conversion is charged to the charging device through the first power supply terminal (D11, ..., Dn1). The third winding and the fourth winding obtain electric energy from the grid side through the multi-pulse transformer, and input it into the second AC-DC conversion unit for AC-DC conversion. The DC power output by the second AC-DC conversion unit after the conversion is charged to the charging device through the second power supply terminal (D12, ..., Dn2).

[0103] The phases of the output voltages of the first winding, the third winding, the second winding, and the fourth winding are shifted to the left or right by 15° in sequence. The shift to the left in sequence means, for example, that the output voltage phase of the third winding is shifted to the left (or right) by 15° relative to the output voltage phase of the first winding, the output voltage phase of the second winding is shifted to the left (or right) by 15° relative to the output voltage phase of the third winding, and the output voltage phase of the fourth winding is shifted to the left (or right) by 15° relative to the output voltage phase of the second winding. In this embodiment, while each power supply device realizes dual-output power supply, grid-side harmonics are suppressed, reducing circuit costs.

[0104] For example, when a charging device is connected to the first power supply terminal for charging, in addition to the fundamental wave component, the current flowing into the power grid ideally only contains 12k±1 harmonic currents k=1,2,3…, and k is an odd number of 6k±1 harmonic currents that cancel each other out; when two charging devices are connected to the first power supply terminal and the second power supply terminal for charging, in addition to the fundamental wave component, the current flowing into the power grid ideally only contains 24k±1 harmonic currents k=1,2,3…, and k is an odd number of 12k±1 harmonic currents that cancel each other out. The power supply device of this embodiment is compatible and the power supply mode can be flexibly configured according to actual needs.

[0105] In some embodiments, Figure 5 In the embodiment shown, the structures of the first winding, the second winding, the third winding, and the fourth winding can have multiple options. For example, the first winding can be a star winding; the second winding can be a triangle winding; the third winding can be a Yanbian triangle winding; and the fourth winding can be a Yanbian triangle winding. However, the specific structures of the first winding, the second winding, the third winding, and the fourth winding in the present application are not limited, as long as the output voltage phase is shifted to the left or right by 15° in sequence according to the above embodiment.

[0106] In the above embodiment, the first AC-DC conversion unit may be implemented in a variety of ways. Two optional circuit structures of the first AC-DC conversion unit are exemplified below with reference to the accompanying drawings.

[0107] See also Figure 8 , is a schematic diagram of the structure of a first AC-DC conversion unit provided in an embodiment of the present application. Fig. 9 , is another schematic diagram of the structure of the first AC-DC conversion unit provided in an embodiment of the present application. In some embodiments of the first AC-DC conversion unit, the first AC-DC conversion unit includes: a first rectifier bridge unit and a second rectifier bridge unit. Figure 8 and Fig. 9 In the first AC-DC conversion unit structure shown in FIG. 1 , six diodes D 11 , D 12 , D 13 , D 14 , D 15 , D 16 The first rectifier bridge unit consists of six diodes D 21 , D 22 , D 23 , D 24 , D 25 , D 26 The first AC-DC conversion unit may also include more rectifier elements. Figure 8 , Fig. 9 The structure shown is only an example, and the present application is not limited thereto.

[0108] See also Figure 8 , Fig. 9, the first rectifier bridge unit is connected to the first winding, and the input end of the first rectifier bridge unit is connected to the output end of the first winding. The three-phase AC power input by the first winding enters the first rectifier bridge unit for rectification processing to achieve AC to DC conversion. The second rectifier bridge unit is connected to the second winding, and the input end of the second rectifier bridge unit is connected to the output end of the second winding. The three-phase AC power input by the second winding enters the second rectifier bridge unit for rectification processing to achieve AC to DC conversion. The first DC-DC conversion unit is connected between the first port B1+, B1- and the first power supply end.

[0109] There are at least two ways to connect the output ends of the first rectifier bridge unit and the second rectifier bridge unit, such as Figure 8 A schematic diagram of a connection method of output terminals in series, and Fig. 9 Another output terminal parallel connection method is shown in FIG.

[0110] In some embodiments, see Figure 8 The output ends of the first rectifier bridge unit and the second rectifier bridge unit are connected in series to form first ports B1+ and B1-, and the first ports B1+ and B1- are connected to the first power supply end. The first AC-DC conversion unit may also include: a first DC-DC conversion unit. Figure 8 As shown, the first DC-DC conversion unit is connected between the first ports B1+, B1- and the first power supply terminal.

[0111] In some other embodiments, see Fig. 9 In the first AC-DC conversion unit, the output ends of the first rectifier bridge unit and the second rectifier bridge unit may be connected in parallel to form first ports B1+ and B1-, and the first ports B1+ and B1- are connected to the first power supply end. Fig. 9 As shown, the first AC-DC conversion unit may further include: a first DC-DC conversion unit. The first DC-DC conversion unit is connected between the first ports B1+, B1- and the first power supply terminal.

[0112] In some embodiments of the second AC-DC conversion unit, the second AC-DC conversion unit includes: a third rectifier bridge unit and a fourth rectifier bridge unit. The second AC-DC conversion unit may also include more rectifier elements, but the following example is taken as an example of a structure including the third rectifier bridge unit and the fourth rectifier bridge unit, and the present application is not limited thereto.

[0113] In some embodiments, the input end of the third rectifier bridge unit is connected to the output end of the third winding. The three-phase alternating current input by the third winding enters the third rectifier bridge unit for rectification processing to achieve the conversion from AC to DC. The input end of the fourth rectifier bridge unit is connected to the output end of the fourth winding. The three-phase alternating current input by the fourth winding enters the fourth rectifier bridge unit for rectification processing to achieve the conversion from AC to DC. Among them, the connection mode between the third rectifier bridge unit and the fourth rectifier bridge unit can have at least two optional series and parallel connections as follows.

[0114] In some embodiments, the output ends of the third rectifier bridge unit and the fourth rectifier bridge unit are connected in series to form a second port, and the second port is connected to the second power supply end. The second AC-DC conversion unit may also include: a second DC-DC conversion unit. The second DC-DC conversion unit is connected between the second port and the second power supply end. Figure 8 The structure of the first rectifier bridge unit and the second rectifier bridge unit constituting the first port is similar.

[0115] In some other embodiments, the output ends of the third rectifier bridge unit and the fourth rectifier bridge unit are connected in parallel to form a second port, and the second port is connected to the second power supply end. The second AC-DC conversion unit may also include: a second DC-DC conversion unit. The second DC-DC conversion unit is connected between the second port and the second power supply end. Fig. 9 The structure of the first rectifier bridge unit and the second rectifier bridge unit constituting the first port is similar.

[0116] In the above embodiment, the structures of the first DC-DC conversion unit and the second DC-DC conversion unit may be the same or different, and their specific structures are not limited here.

[0117] Based on the above embodiments, see Fig.10 , is a schematic diagram of the structure of another first AC-DC conversion unit provided in an embodiment of the present application. Fig.10 The first AC-DC conversion unit shown in the figure includes a first DC-DC conversion unit, which mainly includes a bus capacitor C BH , C BL , power tube Q 51 , Q 52 , Q 53 , Q 54 , Q 55 , Q 56 , Q 57 , Q 58 , output inductor L 51 , L 52 , L 53 , L 54 , and the output capacitor C 51, C 52 Among them, the power tube Q 51 , Q 52 , Q 53 , Q 54 The first DC conversion circuit is formed, and the power tube Q 55 , Q 56 , Q 57 , Q 58 The second DC conversion circuit is formed, but the present application is not limited thereto. The current obtained from the first port B1+ and B1- passes through Fig.10 The first DC-DC conversion unit performs conversion to output direct current to the first power supply end.

[0118] In some embodiments, for example Figure 8 and Fig. 9 In the embodiment shown, the first rectifier bridge unit and the second rectifier bridge unit are both rectifier bridge units with uncontrolled rectification, which have a simple circuit structure and low cost. However, the first rectifier bridge unit and the second rectifier bridge unit may also be rectifier bridge units with active rectification, which is not limited here.

[0119] In some embodiments, the third rectifier bridge unit and the fourth rectifier bridge unit are both rectifier bridge units with uncontrolled rectification, which have simple circuit structures and low costs. However, the third rectifier bridge unit and the fourth rectifier bridge unit may also be rectifier bridge units with active rectification, which is not limited here.

[0120] In the above embodiments, preferably, the structures of the first rectifier bridge unit, the second rectifier bridge unit, the third rectifier bridge unit and the fourth rectifier bridge unit are consistent. When the two power supply ends work at the same time, the 12k±1 grid-side harmonic currents where k is an odd number can be completely offset by each other, and the power factor effect is better.

[0121] In some embodiments, the primary winding of the multi-pulse transformer may be a star winding or a delta winding.

[0122] In some embodiments, the number of power supply devices is greater than or equal to 2. If the number of power supply devices is Z, then the charging system can provide 2Z power supply ports to meet the charging needs of 2Z charging devices. Compared with the charging system composed of Z single-power supply port power supply devices in the prior art, this embodiment can configure the power supply port more flexibly, obtain double the number of power supply ports, and improve resource utilization.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A charging system, characterized in that: include: A multi-pulse transformer, comprising a primary winding, a magnetic core and a plurality of secondary windings, wherein the plurality of secondary windings form n winding pairs; n AC-DC conversion units, corresponding one to one with the n winding pairs, and an input end of each AC-DC conversion unit is electrically connected to a corresponding winding pair; n power supply terminals, corresponding one to one with the n AC-DC conversion units, each of the power supply terminals being electrically connected to an output terminal of a corresponding AC-DC conversion unit; as well as A charging scheduling device, used to detect the number M of charging devices and the state of the power supply end, and determine M target winding pairs for supplying power to the charging devices from the n winding pairs, wherein the M target winding pairs include the winding pairs distributed near the first end of the magnetic core and the winding pairs distributed near the second end of the magnetic core; The n winding pairs are distributed in sequence along the center line of the magnetic core; The target winding pair for supplying power to the charging device includes at least the i-th winding pair and the ni-th winding pair, wherein , .

2. The system according to claim 1, characterized in that The n winding pairs are distributed in sequence along the center line of the magnetic core; The charging scheduling device is specifically used for: If it is determined that M is 2, two winding pairs sequentially distributed at both ends of the n winding pairs are determined as target winding pairs; If it is determined that M is greater than 2, two winding pairs sequentially distributed at both ends of the n winding pairs and M-2 winding pairs distributed between the two winding pairs are determined as target winding pairs.

3. The system according to claim 2, characterized in that The M-2 target winding pairs distributed between the 2 winding pairs are evenly distributed.

4. The system according to any one of claims 1 to 3, characterized in that: The charging scheduling device is specifically used to set the target winding pair for powering n / 2 charging devices as an interval-distributed winding pair with an interval of 1 winding pair if it is determined that M is greater than n / 2.

5. A charging system, characterized in that: include: Multi-pulse transformer, n power supply devices and charging scheduling device; The multi-pulse transformer comprises: a primary winding, a magnetic core and a plurality of secondary windings, wherein the plurality of secondary windings form 2n winding pairs; Each of the power supply devices corresponds to two winding pairs, and the power supply device includes: a first AC-DC conversion unit and a second AC-DC conversion unit; wherein the input end of the first AC-DC conversion unit is electrically connected to one of the two winding pairs, and the output end of the first AC-DC conversion unit is a first power supply end; the input end of the second AC-DC conversion unit is electrically connected to the other of the two winding pairs, and the output end of the second AC-DC conversion unit is a second power supply end; The charging scheduling device is used to detect the number M of charging devices and the status of the power supply end, and determine the target winding pair for powering the charging device among the 2n winding pairs, wherein the multiple target winding pairs include the winding pair distributed near the first end of the magnetic core and the winding pair distributed near the second end of the magnetic core.

6. The system according to claim 5, characterized in that The winding pair connected to the first AC-DC conversion unit includes a first winding and a second winding, and the winding pair connected to the second AC-DC conversion unit includes a third winding and a fourth winding; the phases of the output voltages of the first winding, the third winding, the second winding, and the fourth winding are shifted left or right by 15° respectively.

7. The system according to claim 6, characterized in that The 2n winding pairs are distributed in sequence along the center line of the magnetic core.

8. The system according to claim 7, characterized in that The charging scheduling device is specifically used for: If M is determined to be 3, two winding pairs sequentially distributed at both ends of the 2n winding pairs and an adjacent winding pair of one of the two winding pairs are determined as target winding pairs, wherein the adjacent winding pair and one of the two winding pairs correspond to the same power supply device.

9. The system according to claim 7, characterized in that The charging scheduling device is specifically used for: If it is determined that M is greater than or equal to 4, the two winding pairs distributed at the first end of the magnetic core and the two winding pairs distributed at the second end of the magnetic core are used as the four target winding pairs for powering four of the charging devices, wherein the two winding pairs distributed at the first end of the magnetic core both correspond to one power supply device, and the two winding pairs distributed at the second end of the magnetic core both correspond to another power supply device.

10. The system according to claim 9, characterized in that The charging scheduling device is specifically used for: If it is determined that M is greater than 4, then in the winding pairs between the two winding pairs distributed at the first end of the magnetic core and the two winding pairs distributed at the second end of the magnetic core, determine the remaining target winding pair.

11. The system according to claim 10, characterized in that M is an even number, and the rest The target winding pair is electrically connected to A power supply unit.

12. The system according to claim 10, characterized in that The two winding pairs distributed at the first end of the magnetic core and the two windings distributed between the two windings at the second end of the magnetic core target winding pairs, evenly distributed.

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