Charging system and method for controlling charging system

Abstract

To provide a charging system capable of corresponding to various charging specifications while an increase in size and cost is suppressed in a multi-port type charging system which can simultaneously charge a plurality of loads and storage batteries.SOLUTION: A charging system includes a plurality of transformer units each of which is configured of a primary side circuit and a secondary side circuit, which are insulated by a high frequency transformer, and input terminals of the primary side circuits of the plurality of transformer units are connected in series. At least one transformer unit in the plurality of transformer units includes a plurality of secondary side circuits, and output terminals of the plurality of secondary side circuits are connected to a plurality of different loads.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the configuration and control of a charging system, and in particular to a technique that is effective when applied to a multi-port charger that can simultaneously charge a plurality of loads or storage batteries with different charging specifications. [Background technology]

[0002] As electric vehicles (EVs) become more widespread, demand for various types of chargers is expected to increase. In particular, multi-port chargers, which combine a converter panel with a built-in solid-state transformer (SST) and multiple user terminals (EV ports), are compact and can charge multiple EVs simultaneously, so they are expected to become popular in a variety of locations, such as parking lots within buildings, convenience stores, shopping malls, and residential areas.

[0003] Meanwhile, in the logistics sector, the conversion of delivery vehicles to electric vehicles is being considered, but charging of delivery EVs is concentrated during loading and driver breaks. If chargers are limited to specific vehicle uses, improving the utilization rate of charging facilities becomes an issue. For example, sharing chargers among EVs for different purposes, such as regular cars, commercial trucks, and buses, can be expected to improve facility utilization, but adapting to the widely differing charging specifications (voltage, power) that result from differences in battery specifications (voltage, capacity) and usage conditions (normal charging, rapid charging) presents a challenge.

[0004] Background art in this technical field includes, for example, technology such as that disclosed in Patent Document 1. Patent Document 1 discloses a power supply device that can maintain primary-side voltage balance even when charging power differs greatly between power storage devices by sharing a high-frequency transformer core among multiple cell units.

[0005] Furthermore, Patent Document 2 discloses a multi-port power conversion system that can reduce the load on the converter and improves versatility in response to changes in battery voltage specifications. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-182257 [Patent Document 2] Patent Publication No. 2021-27768 Summary of the Invention [Problem to be solved by the invention]

[0007] The multi-port charger described above is generally configured with the primary input terminals of multiple solid-state transformers (SSTs, hereafter referred to as "transformer units") installed within a converter panel connected in series. To ensure voltage balance in the series-connected primary circuits, there are restrictions on the power imbalance conditions between the transformer units, making it difficult to simultaneously charge loads with significantly different charging specifications. While it is possible to expand the range of charging specifications that can be simultaneously charged by reducing the voltage and power shared by each unit and increasing the number of units, this leads to an increase in the size and cost of the multi-port charger as the system scale increases.

[0008] In the above Patent Document 1, a special transformer is required, which is large in size.

[0009] Furthermore, in Patent Document 2, the power balance between the transformer units is not taken into consideration, making it difficult to simultaneously charge loads with significantly different charging specifications.

[0010] Therefore, an object of the present invention is to provide a charging system and a control method for a charging system that can accommodate a variety of charging specifications while suppressing increases in size and cost in a multi-port charging system capable of simultaneously charging multiple loads and storage batteries. [Means for solving the problem]

[0011] In order to solve the above problems, the present invention provides a charging system including a plurality of transformer units each composed of a primary circuit and a secondary circuit insulated by a high-frequency transformer, the input terminals of the primary circuits of the plurality of transformer units being connected in series, at least one of the plurality of transformer units having a plurality of secondary circuits, the output terminals of the plurality of secondary circuits being connected to a plurality of different loads. AC power is input to the input terminal of the primary side circuit, DC power is output from the output terminals of the plurality of secondary circuits, and the primary circuit of the transformer unit having the plurality of secondary circuits is configured by a combination of one AC / DC conversion circuit and a plurality of DC / AC conversion circuits. It is characterized by the following.

[0012] The present invention also provides the above A control method for a charging system, comprising: (a) different The plurality of transformer units are determined based on the charging capacity of each load, the rated power of each transformer unit, and the total number of the transformer units. different (b) determining the number of main ports to be assigned to each load and the number of sub-ports branched from the main ports; different and determining an output power command to be supplied to each of the loads. [Effects of the Invention]

[0013] According to the present invention, in a multi-port charging system capable of simultaneously charging multiple loads and storage batteries, it is possible to realize a charging system and a control method for the charging system that can accommodate a variety of charging specifications while suppressing increases in size and cost.

[0014] This will enable simultaneous charging of EVs for different purposes, such as regular cars, commercial trucks, and buses, thereby improving the utilization rate of charging facilities.

[0015] Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a circuit diagram showing a schematic configuration of a charging system according to a first embodiment of the present invention. [Figure 2]FIG. 6 is a circuit diagram showing a schematic configuration of a charging system according to a second embodiment of the present invention. [Figure 3] FIG. 10 is a circuit diagram showing a schematic configuration of a charging system according to a third embodiment of the present invention. [Figure 4] 4 is a timing chart showing an example of the operation of the charging system of FIG. 3. [Figure 5] FIG. 10 is a circuit diagram showing a schematic configuration of a charging system according to a fourth embodiment of the present invention. [Figure 6] 6 is a timing chart showing an example of the operation of the charging system of FIG. 5. [Figure 7] 10 is a flowchart showing a control method (port distribution mode) of a charging system according to a fifth embodiment of the present invention. [Figure 8] 10 is a flowchart showing a control method (charging mode) of a charging system according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same components are designated by the same reference numerals, and detailed description of overlapping parts will be omitted. [Example]

[0018] A charging system according to a first embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a circuit diagram showing a schematic configuration of a charging system 1 of this embodiment.

[0019] As shown in FIG. 1, the charging system 1 of this embodiment includes a voltage transformer unit 2 and a voltage transformer unit 3 as its main components.

[0020] The charging system 1 is provided with input terminals 4 to 7 as input terminals, and with output terminals 8 to 13 as output terminals.

[0021] Input terminals 4 to 7 are connected to a power supply source (not shown), and AC power is input from the power supply source via input terminals 4 to 7. Input terminal 5 and input terminal 6 are connected in series.

[0022] The output terminals 8 to 13 are connected to a load (not shown) or a storage battery (battery) of an EV or a transport robot, and the power converted from AC power to DC power by the charging system 1 is output to the load or storage battery (battery) via the output terminals 8 to 13.

[0023] In addition, since storage batteries (batteries) for EVs and transport robots can also be considered loads in a broad sense, we will use the term "load" in the following explanation.

[0024] The primary circuit of transformer unit 2 is composed of a combination of an AC / DC conversion circuit made up of switching elements H1 to H4 and multiple (here, two) DC / AC conversion circuits made up of switching elements Qa1 to Qa4 and switching elements Qb1 to Qb4. A capacitor C11 is disposed as a smoothing capacitor at the connection between the AC / DC conversion circuit and the DC / AC conversion circuit.

[0025] The secondary circuit of the transformer unit 2 is composed of a combination of a rectifier circuit 14 consisting of diodes D21 to D24, an inductance L21, and a capacitor C21, a chopper circuit 15 consisting of an inductance Lb1, a switching element Sb1, a diode Db1, and a capacitor C22, a rectifier circuit 14 consisting of diodes D31 to D34, an inductance L31, and a capacitor C31, and a chopper circuit 15 consisting of an inductance Lb2, a switching element Sb2, a diode Db2, and a capacitor C32.

[0026] The rectifier circuit 14 and chopper circuit 15 of the secondary side circuit of the transformer unit 2 are combined to form an AC / DC conversion circuit.

[0027] Between the multiple (two) DC / AC conversion circuits of the primary circuit of the transformer unit 2 and the multiple (two) rectifier circuits 14 of the secondary circuit, an inductance Lra and a high-frequency transformer Tra, and an inductance Lrb and a high-frequency transformer Trb are arranged, respectively. The primary circuit and the secondary circuit are insulated by the high-frequency transformers Tra and Trb, and AC power is transmitted from the primary circuit to the secondary circuit by high-frequency coupling.

[0028] The primary circuit of the transformer unit 3 is configured by a combination of an AC / DC conversion circuit made up of switching elements H1 to H4 and a DC / AC conversion circuit made up of switching elements Qa1 to Qa4. A capacitor C11 is disposed as a smoothing capacitor at the connection between the AC / DC conversion circuit and the DC / AC conversion circuit.

[0029] The secondary circuit of the transformer unit 3 is composed of a rectifier circuit 14 consisting of diodes D21 to D24, an inductor L21, and a capacitor C21, and a chopper circuit 15 consisting of an inductor Lb1, a switching element Sb1, a diode Db1, and a capacitor C22.

[0030] An inductance Lra and a high-frequency transformer Tra are arranged between the DC / AC conversion circuit of the primary circuit of the transformer unit 3 and the rectifier circuit 14 of the secondary circuit. The primary circuit and secondary circuit are insulated by the high-frequency transformer Tra, and AC power is transmitted from the primary circuit to the secondary circuit by high-frequency coupling.

[0031] As described above, the charging system 1 of this embodiment includes a plurality of transformer units each composed of a primary circuit and a secondary circuit insulated by high-frequency transformers Tra and Trb, and the input terminals 5 and 6 of the primary circuits of the plurality of transformer units 2 and 3 are connected in series. At least one transformer unit 2 of the plurality of transformer units 2 and 3 has a plurality of secondary circuits, and the output terminals 8 and 9 and 10 and 11 of the plurality of secondary circuits are connected to different loads (not shown).

[0032] This means that, for example, if the rated power of both transformer units 2 and 3 is 10 kW, an EV with a power requirement of 5 kW can be assigned and connected to output terminals 8 and 9 of transformer unit 2, while an EV with a power requirement of up to 15 kW can be assigned and connected to output terminals 10 and 11 of transformer unit 2 and output terminals 12 and 13 of transformer unit 3.

[0033] In other words, the rated power of unit 2 is 10 kW, and the output power of 5 kW from output terminals 8 and 9 is subtracted to output the remaining 5 kW from output terminals 10 and 11. When combined with the output power of 10 kW from output terminals 12 and 13 of transformer unit 3, a maximum output power of 15 kW can be supplied.

[0034] Although FIG. 1 shows an example in which two transformer units 2 and 3 are arranged within the charging system 1, by increasing the number of transformer units built into the charging system 1, it is possible to accommodate EVs with larger capacities.

[0035] Although not shown, for example, if two more transformer units with the same configuration as transformer unit 3 are added to charging system 1 to form a four-unit configuration, an EV with a power requirement of 5 kW can be assigned and connected to output terminals 8 and 9 of transformer unit 2, while output terminals 10 and 11 of transformer unit 2 and output terminals 12 and 13 of transformer unit 3, as well as the output terminals of the two additional transformer units, can be assigned and connected to an EV with a power requirement of up to 35 kW.

[0036] It is also possible to assign and connect an EV with a power requirement of 5 kW to output terminals 8 and 9 of transformer unit 2, assign and connect an EV with a power requirement of 15 kW to output terminals 10 and 11 of transformer unit 2 and output terminals 12 and 13 of transformer unit 3, and assign and connect an EV with a power requirement of 20 kW to the output terminals of the two additional transformer units.

[0037] The charging system 1 of this embodiment can realize a charging system that can accommodate a variety of charging specifications while suppressing increases in size and cost. [Example]

[0038] Second Embodiment A charging system according to a second embodiment of the present invention will be described with reference to Fig. 2. Fig. 2 is a circuit diagram showing a schematic configuration of a charging system 1 of this embodiment, which corresponds to a modified example of the first embodiment (Fig. 1).

[0039] In the charging system 1 of Example 1 (Figure 1), the primary side circuit of the transformer unit 2 is composed of a combination of an AC / DC conversion circuit composed of switching elements H1 to H4 and multiple (two) DC / AC conversion circuits composed of switching elements Qa1 to Qa4 and switching elements Qb1 to Qb4.

[0040] In contrast, in the charging system 1 of this embodiment, as shown in Fig. 2, the primary circuit of the transformer unit 2 is configured by combining an AC / DC conversion circuit configured with switching elements H1 to H4 and one DC / AC conversion circuit configured with switching elements Qa1 to Qa4. That is, the primary circuit of the transformer unit 2 does not have a DC / AC conversion circuit configured with switching elements Qb1 to Qb4, and the two rectifier circuits 14 of the secondary circuit share one high-frequency transformer Tra and are high-frequency coupled to the primary circuit. The other configurations are the same as those of the first embodiment (Fig. 1).

[0041] By adopting a configuration such as that of this embodiment (FIG. 2), the number of elements in the primary side circuit of the transformer unit 2 can be reduced. [Example]

[0042] A charging system according to a third embodiment of the present invention will be described with reference to Fig. 3 and Fig. 4. Fig. 3 is a circuit diagram showing a schematic configuration of the charging system 1 of this embodiment. Fig. 4 is a timing chart showing an example of the operation of the charging system 1 of Fig. 3.

[0043] In the first and second embodiments, examples of an AC / DC conversion type charging system that converts AC power supplied from a power supply source into DC power and outputs it to a load have been described. In the present embodiment, however, an example of a DC / DC conversion type charging system that performs power conversion (voltage conversion, frequency conversion) on DC power supplied from a power supply source and outputs it to a load will be described.

[0044] The charging system 1 of this embodiment includes a voltage transformer unit 2 and a voltage transformer unit 3 as main components, similar to the first embodiment (FIG. 1).

[0045] The charging system 1 is provided with input terminals 4 to 7 as input terminals, and with output terminals 8 to 13 as output terminals.

[0046] Input terminals 4 to 7 are connected to a power supply source (not shown), and DC power is input from the power supply source via input terminals 4 to 7. Input terminal 5 and input terminal 6 are connected in series.

[0047] A load (not shown) is connected to the output terminals 8-13, and DC power converted (voltage converted, frequency converted) by the charging system 1 is output to the load via the output terminals 8-13.

[0048] The primary circuit of the transformer unit 2 is made up of a plurality of (here, two) DC / AC conversion circuits each consisting of switching elements Qa1 to Qa4 and switching elements Qb1 to Qb4. A capacitor C11 is disposed on the input side of the DC / AC conversion circuit as a smoothing capacitor.

[0049] The secondary circuit of transformer unit 2 is made up of multiple (here, two) AC / DC conversion circuits, each consisting of switching elements Q21-Q24 and switching elements Q31-Q34. Capacitors C21 and C31 are arranged as smoothing capacitors on the output side of the AC / DC conversion circuits.

[0050] Between the multiple (two) DC / AC conversion circuits of the primary circuit of the transformer unit 2 and the multiple (two) AC / DC conversion circuits of the secondary circuit, an inductance Lra and a high-frequency transformer Tra, and an inductance Lrb and a high-frequency transformer Trb are arranged, respectively. The primary and secondary circuits are insulated by the high-frequency transformers Tra and Trb, and AC power is transmitted from the primary circuit to the secondary circuit by high-frequency coupling.

[0051] The primary circuit of the transformer unit 3 is made up of a DC / AC conversion circuit made up of switching elements Qa1 to Qa4. A capacitor C11 is disposed as a smoothing capacitor on the input side of the DC / AC conversion circuit.

[0052] The secondary circuit of transformer unit 3 is made up of an AC / DC conversion circuit made up of switching elements Q21 to Q24. A capacitor C21 is disposed as a smoothing capacitor on the output side of the AC / DC conversion circuit.

[0053] An inductance Lra and a high-frequency transformer Tra are arranged between the DC / AC conversion circuit of the primary circuit of the transformer unit 3 and the AC / DC conversion circuit of the secondary circuit. The primary circuit and secondary circuit are insulated by the high-frequency transformer Tra, and AC power is transmitted from the primary circuit to the secondary circuit by high-frequency coupling.

[0054] As described above, the charging system 1 of this embodiment includes a plurality of transformer units each composed of a primary circuit and a secondary circuit insulated by high-frequency transformers Tra and Trb, and the input terminals 5 and 6 of the primary circuits of the plurality of transformer units 2 and 3 are connected in series. At least one transformer unit 2 of the plurality of transformer units 2 and 3 has a plurality of secondary circuits, and the output terminals 8 and 9 and 10 and 11 of the plurality of secondary circuits are connected to different loads (not shown).

[0055] As a result, similar to Examples 1 and 2, for example, if the rated power of transformer units 2 and 3 is both 10 kW, an EV with a required power of 5 kW can be assigned and connected to output terminals 8 and 9 of transformer unit 2, while an EV with a required power of up to 15 kW can be assigned and connected to output terminals 10 and 11 of transformer unit 2 and output terminals 12 and 13 of transformer unit 3.

[0056] In other words, the rated power of unit 2 is 10 kW, and the output power of 5 kW from output terminals 8 and 9 is subtracted to output the remaining 5 kW from output terminals 10 and 11. When combined with the output power of 10 kW from output terminals 12 and 13 of transformer unit 3, a maximum output power of 15 kW can be supplied.

[0057] FIG. 4 shows an example of the ON / OFF operation of each switching element in the charging system 1 of FIG.

[0058] As shown in FIG. 4, the charging system 1 of this embodiment can control the power output from the transformer unit 2 by changing the timing (phases Φ1, Φ2) of the ON / OFF operation of the switching elements Q21 to Q24 and switching elements Q31 to Q34 that constitute multiple (two) AC / DC conversion circuits in the secondary circuit of the transformer unit 2.

[0059] In the above, the symbols 4 to 7 are described as input terminals and the symbols 8 to 13 as output terminals, but as shown in Figure 3, both transformer units 2 and 3 have a DAB (Dual Active Bridge) configuration with full bridge circuits on both the primary and secondary sides, so symbols 8 to 13 can be used as input terminals and symbols 4 to 7 as output terminals in both directions. [Example]

[0060] A charging system according to a fourth embodiment of the present invention will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is a circuit diagram showing a schematic configuration of a charging system 1 of this embodiment, which corresponds to a modified example of the third embodiment (Fig. 3). Fig. 6 is a timing chart showing an example of the operation of the charging system of Fig. 5.

[0061] In the charging system 1 of the third embodiment (FIG. 3), the primary circuit of the transformer unit 2 is made up of a plurality of (two) DC / AC conversion circuits each made up of switching elements Qa1 to Qa4 and switching elements Qb1 to Qb4.

[0062] In contrast, in the charging system 1 of this embodiment, as shown in Fig. 5, the primary circuit of the transformer unit 2 is configured with one DC / AC conversion circuit made up of switching elements Qa1 to Qa4. That is, the primary circuit of the transformer unit 2 does not have a DC / AC conversion circuit made up of switching elements Qb1 to Qb4, and the two AC / DC conversion circuits of the secondary circuit share one DC / AC conversion circuit of the primary circuit, and are each high-frequency coupled to the one DC / AC conversion circuit of the primary circuit by high-frequency transformers Tra and Trb. The other configurations are the same as those of the third embodiment (Fig. 3).

[0063] By adopting a configuration such as that of this embodiment (FIG. 5), the number of elements in the primary side circuit of the transformer unit 2 can be reduced.

[0064] In this embodiment, as shown in FIG. 6, the power output from the transformer unit 2 can be controlled by changing the timing (phases Φ1, Φ2) of the ON / OFF operation of the switching elements Q21 to Q24 and the switching elements Q31 to Q34 that constitute the multiple (two) AC / DC conversion circuits in the secondary circuit of the transformer unit 2. [Example]

[0065] A control method for a charging system according to a fifth embodiment of the present invention will be described with reference to Fig. 7 and Fig. 8. Fig. 7 is a flowchart showing a port distribution mode in the control method for a charging system according to this embodiment. Fig. 8 is a flowchart showing a charging mode in the control method for a charging system according to this embodiment.

[0066] In this embodiment, a method for distributing ports (output terminals) of the charging system 1 described in the first to fourth embodiments and a subsequent charging method will be described.

[0067] As shown in FIG. 7, when the port distribution mode starts in step S71, the charging power Pc_x of the loads is sorted in ascending or descending order in step S72.

[0068] Next, in step S73, the number Npm_x of main ports (e.g., output terminals 8, 9 and 12, 13 in Figure 1) to be assigned to each load and the number Nps_x of sub-ports branched from the main ports (e.g., output terminals 10, 11 in Figure 1) are calculated from the charging power Pc_x of each load, the rated power Pconv of the converter (transformer unit), and the total number of units Nu.

[0069] Here, Np_x=Pc_x / Pconv×Nu, where x is the number of loads (a natural number).

[0070] If Np_x<1, the number of sub-ports to be allocated is determined in the following procedure.

[0071] The number of sub-ports to be allocated is calculated using the following formula (1).

[0072]

number

[0073] Nps_x (round off to the nearest whole number), Ks=Pu_sub / Pu_main Pu_sub: Rated power of sub-port, Pu_main: Rated power of main port If Np_x≧1, the value rounded down to the nearest integer is set as the number of main ports allocated Npm_x.

[0074] If there are any remaining sub-ports after the allocation calculation is completed, the sub-ports are allocated in order from the load with the largest charging power.

[0075] If there are loads with the same charging power, the load with the earliest desired charging completion time or the load with the larger amount of charging power is determined to be the load with the larger charging power.

[0076] Subsequently, in step S74, an output power command Pout_x to be supplied to each load is calculated.

[0077] Specifically, the output power command Pout_x is calculated by the following method.

[0078] (i) The provisional value Pu01 of the output power of the main port is calculated using equation (2).

[0079]

number

[0080] (ii) Using Pu01 and the load Pc_min with the smallest output power assigned to the subport, the provisional value of the power output from the remaining subport, Pu02, is calculated using equation (3).

[0081]

number

[0082] where Nps_sum is the total number of sub-boats.

[0083] At this time, if Pu02>Pu_sub, Pu02=Pu_sub is set, and Pu01 is updated using equation (4).

[0084]

number

[0085] (iii) The provisional value Pout0_x of the power to be supplied to each load is calculated using equation (5).

[0086]

number

[0087] (iv) A provisional value Pout0_x of the power to be supplied to each load is compared with the required charging power Pc_x, and if Pout0_x≦Pc_x for all loads, the power is output as is as the output power command Pout_z.

[0088] If there is a load condition where Pout0_x>Pc_x in (v) and (iv), the adjustment amount ΔPout is calculated, and adjusted provisional values ​​Pu11 and Pu12 are obtained by subtracting the adjustment amount ΔPout from the provisional values ​​Pu01 and Pu02 of each port.

[0089]

number

[0090]

number

[0091]

number

[0092] (vi) Using the adjusted provisional values ​​Pu11 and Pu12 of each port, the power command Pout_x to be supplied to each load is calculated using equation (9).

[0093]

number

[0094] In step S75, the port distribution mode is ended and the mode shifts to the charging mode shown in FIG.

[0095] As shown in FIG. 8, when the charging mode starts in step S81, the current charging power Pc_x(t) is detected in step S82.

[0096] Next, in step S83, the difference ΔPc_x between the detected value Pc_x(t) and the value Pc_x_int at the start of the charging mode is calculated using equation (10).

[0097]

number

[0098] Subsequently, in step S84, the difference ΔPc_x obtained in step S83 is compared with a predetermined threshold value Pref1.

[0099] If it is determined that the difference ΔPc_x is greater than the predetermined threshold Pref1 (Yes), the process proceeds to step S89, where the charging mode is terminated. Depending on the demand of the charging system 1, the process again transitions to the port distribution mode of FIG.

[0100] On the other hand, if it is determined that the difference ΔPc_x is equal to or smaller than the predetermined threshold Pref1 (No), the process proceeds to step S85, where the difference ΔPc_x is compared with another threshold Pref2 different from the threshold Pref1.

[0101] If it is determined that the difference ΔPc_x is greater than the threshold Pref2 (Yes), the process proceeds to step S86. On the other hand, if it is determined that the difference ΔPc_x is equal to or less than the threshold Pref2 (No), the process returns to step S82 and repeats the processes from step S82 onwards.

[0102] Next, in step S86, the allocated power for each port is updated.

[0103] Specifically, Pu1_new and Pu2_new are calculated using the following method.

[0104] (i) The adjusted power ΔPu of each port is calculated using equation (11).

[0105]

number

[0106] (ii) Using the adjusted power Δpu and the current allocated powers Pu1 and Pu2 of each port, updated allocated powers Pu1_new and Pu2_new are calculated using equations (12) and (13).

[0107]

number

[0108]

number

[0109] Subsequently, in step S87, the output power command Pout_x to be supplied to each load is updated using equation (14).

[0110]

number

[0111] Next, in step S88, the absolute value of the difference (|Pc_x-Pout_x|) between the load charge power Pc_x and the output power command Pout_x is compared with a threshold value Pref3 different from the threshold values ​​Pref1 and Pref2.

[0112] If it is determined that the absolute value of the difference between the load charge power Pc_x and the output power command Pout_x (|Pc_x - Pout_x|) is greater than the threshold Pref3 (Yes), the process proceeds to step S89, where the charging mode is terminated. Depending on the demand of the charging system 1, the process returns to the port distribution mode shown in FIG.

[0113] On the other hand, if it is determined that the absolute value of the difference between the load charge power Pc_x and the output power command Pout_x (|Pc_x-Pout_x|) is equal to or smaller than the threshold value Pref3 (No), the process returns to step S82, and the processes from step S82 onwards are repeated.

[0114] The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations. [Explanation of symbols]

[0115] 1. Charging system 2,3...Transformer unit 4, 5, 6, 7...Input terminals 8, 9, 10, 11, 12, 13...Output terminals 14... Rectifier circuit 15...Chopper circuit H1 to H4, Qa1 to Qa4, Qb1 to Qb4, Q21 to Q24, Q31 to Q34...Switching elements C11, C21, C22, C31, C32... Capacitors Lra, Lrb, L21, L31, Lb1, Lb2...Inductance Tra,Trb...High frequency transformer D21~D24, D31~D34, Db1, Db2...Diodes Sb1, Sb2...Switching elements

Claims

1. A charging system including a plurality of transformer units each including a primary circuit and a secondary circuit insulated by a high-frequency transformer, wherein input terminals of the primary circuits of the plurality of transformer units are connected in series, At least one of the plurality of transformer units has a plurality of secondary circuits, output terminals of the plurality of secondary side circuits are connected to a plurality of different loads; AC power is input to the input terminal of the primary side circuit, DC power is output from output terminals of the plurality of secondary side circuits, A charging system characterized in that the primary side circuit of the transformer unit having the plurality of secondary side circuits is configured by a combination of one AC / DC conversion circuit and a plurality of DC / AC conversion circuits.

2. 2. The charging system according to claim 1, A charging system, wherein each of the plurality of secondary circuits is configured with a rectifier circuit and a chopper circuit.

3. 2. The charging system according to claim 1, A charging system, wherein each of the plurality of secondary circuits is configured as a full-bridge circuit.

4. 2. The charging system according to claim 1, 10. A charging system according to claim 9, wherein the load is a battery of an electric vehicle or a transport robot.

5. A control method for a charging system according to any one of claims 1 to 4, (a) determining the number of main ports to be assigned to each of the plurality of different loads and the number of sub-ports branched from the main port based on the charging capacities of the plurality of different loads, the rated powers of the plurality of transformer units, and the total number of the plurality of transformer units; (b) determining an output power command to be supplied to each of the plurality of different loads; A method for controlling a charging system, comprising:

6. 6. A control method for a charging system according to claim 5, (c) after the step (b), charging each of the plurality of different loads from each of the plurality of transformer units based on the output power command; (d) detecting a current charging power of each of the plurality of different loads; (e) calculating a difference between the current charging power detected in the step (d) and the charging power at the start of charging in the step (c); (f) comparing the difference obtained in step (e) with a predetermined threshold value; and a step (f) for updating an output power command to be supplied to each of the plurality of different loads when it is determined that the difference is greater than the predetermined threshold value;

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