Charging system and control device for charging system

Abstract

To provide a charging system capable of appropriately allocating a power conversion unit to a charging target apparatus.SOLUTION: When a new charging target apparatus (42-k) is connected to any charging port (40-k), a unit allocation section 54 reduces an allocation unit number Nm preferentially for an apparatus of a minimum reduction of charge power in a case where the allocation unit number Nm is reduced among charging target apparatuses (42-m) of the plurality of allocation unit numbers Nm, and allocates a power conversion unit 22, which is brought into an idle state by the reduction, to the newly connected charging target apparatus (42-k).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a charging system and a control device for a charging system.

Background Art

[0002] As background art in this technical field, in claim 1 of Patent Document 1 below, "In a charging device for charging a storage battery mounted on an electric vehicle, a plurality of DC power supply units capable of current control and parallel operation, a plurality of power transmission means for connecting to the vehicle and supplying current, operation means for performing charging start and charging stop operations for each vehicle, a matrix switch for allocating a plurality of output circuits of the DC power supply unit to an arbitrary circuit of the plurality of power transmission means, current control means for individually controlling the magnitude of the output current of the DC power supply unit, and switch control means for controlling the matrix switch, wherein the switch control means controls the matrix switch so that one of the DC power supply units is not connected to two or more circuits of the power transmission means, and the current control means controls the DC power supply units allocated by the switch control means to be operated in parallel so that the total output current becomes the current required for charging the storage battery of the vehicle." is described.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the above-described technology, it is preferable that the power conversion unit (DC power supply unit) is appropriately allocated to the device to be charged. The present invention has been made in view of the above circumstances, and an object thereof is to provide a charging system and a control device for the charging system in which a power conversion unit can be appropriately assigned to a device to be charged. [Means for Solving the Problems]

[0005] To solve the above problems, a charging system of the present invention includes a plurality of power conversion units, a plurality of charging ports that supply power to a plurality of devices to be charged, respectively, the aforesaid a switch unit that switches a connection relationship between the power conversion unit the aforesaid and the charging port, to the charging port a unit assignment unit that assigns the power conversion unit, The switch unit is controlled based on the result of the unit allocation unit allocating the power conversion unit to the charging port and a switching control unit. The unit assignment unit When a device to be charged is connected to a certain charging port among the plurality of charging ports, at least one power conversion unit is allocated to the charging port from the plurality of power conversion units allocated to other charging ports is characterized by the following. [Advantages of the Invention]

[0006] According to the present invention, a power conversion unit can be appropriately assigned to a device to be charged. [Brief Description of the Drawings]

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

[0008] [First Embodiment] FIG. 1 is a block diagram of a charging system 1 according to the first embodiment. In Fig. 1, the charging system 1 includes a high-voltage input section 10, a power conversion section 20, a matrix switch section 30 (switch section), four charging ports 40-1 to 40-4, and a control device 50 (charging system control device).

[0009] The charging ports 40-1 to 40-4 are connected to vehicles 42-1 to 42-4 (devices to be charged), such as electric vehicles. In the following description, a plurality of components, information, etc. having the same or similar functions and meanings may be denoted by the same reference numeral with "-" and alphanumeric characters, such as "charging ports 40-1 to 40-4". However, when it is not necessary to distinguish these multiple components, etc., they may be denoted by omitting "-" and alphanumeric characters, such as "charging port 40".

[0010] The high-voltage input section 10 receives power from, for example, a three-phase 6.6 kV AC system 16 (AC power supply), and outputs a three-phase 6.6 kV AC voltage to the lines 18U, 18V, 18W of the U phase, V phase, and W phase via the switch 12 and the reactor 14. The power conversion section 20 includes a total of 21 cell converter units 22 (power conversion units). Between the line 18U and the neutral point 24, the AC terminals (left side in the figure) of seven cell converter units 22-U1 to 22-U7 are connected in series.

[0011] Similarly, between the line 18V and the neutral point 24, the AC terminals of seven cell converter units 22-V1 to 22-V7 are connected in series, and between the line 18W and the neutral point 24, the AC terminals of seven cell converter units 22-W1 to 22-W7 are connected in series. Also, the DC terminals (right side in the figure) of the cell converter units 22-U1, 22-V1, 22-W1 are connected in parallel to the line 26-1. Similarly, the DC terminals of the cell converter units 22-Up, 22-Vp, 22-Wp (where p = 2 to 6) are also connected in parallel to the line 26-p.

[0012] The matrix switch unit 30 includes three DC buses 32-A, 32-B, 32-C and a plurality of switches 34. A total of three switches 34, one each, are connected between the line 26-1 and the DC buses 32-A, 32-B, 32-C, and these switches 34 switch the on / off state of the connection between the line 26-1 and the DC buses 32-A, 32-B, 32-C.

[0013] Similarly, a total of three switches 34, one each, are connected between the line 26-p (where p = 2 to 6) and the DC buses 32-A, 32-B, 32-C, and these switches 34 switch the on / off state of the connection between the line 26-p and the DC buses 32-A, 32-B, 32-C. Also, a total of nine switches 34 are connected between the DC terminals (right side in the figure) of the cell converter units 22-U7, 22-V7, 22-W7 and the DC buses 32-A, 32-B, 32-C. These switches 34 switch the on / off state of the connection between the cell converter units 22-U7, 22-V7, 22-W7 and the DC buses 32-A, 32-B, 32-C.

[0014] The charging ports 40-1, 40-2, 40-3 are respectively connected to the DC buses 32-A, 32-B, 32-C. Also, the charging port 40-4 is connected to both the DC buses 32-A and 32-B. Each charging port 40 supplies the DC power received from the corresponding DC bus 32 to the vehicle 42 connected to the charging port 40, thereby charging a battery (not shown) provided in the vehicle 42. The control device 50 controls each part of the charging system 1. The details of the control device 50 will be described later.

[0015] Figure 2 is a block diagram of the cell converter unit 22. In Figure 2, the cell converter unit 22 includes an AC / DC converter 71, a smoothing capacitor 72, a DC / AC converter 73, a high-frequency transformer 74, an AC / DC converter 75, and a smoothing capacitor 76.

[0016] The AC / DC converter 71 converts the single-phase AC voltage of the commercial frequency input from the input terminal IN into a DC voltage, and supplies it to the DC / AC converter 73 via the smoothing capacitor 72. The DC / AC converter 73 converts the DC voltage into a high-frequency single-phase AC voltage, and supplies it to the AC / DC converter 75 via the high-frequency transformer 74. Here, the high frequency is, for example, a frequency of 100 Hz or higher, but it is preferable to adopt a frequency of 1 kHz or higher, and it is more preferable to adopt a frequency of 10 kHz or higher. The AC / DC converter 75 rectifies this high-frequency single-phase AC voltage, and outputs a DC voltage from the output terminal OUT via the smoothing capacitor 76.

[0017] The AC / DC converters 71, 75 and the DC / AC converter 73 each have four switching elements (not labeled) connected in an H-bridge configuration and diodes (not labeled) connected in anti-parallel to these switching elements. As these switching elements, semiconductor switching elements such as MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) and IGBT (Insulated Gate Bipolar Transistor) can be applied, but other semiconductor switching elements may also be applied.

[0018] Figure 3 is a block diagram of the computer 980. The control device 50 shown in Figure 1 includes one or more computers 980 shown in Figure 3. In Figure 3, the computer 980 includes a CPU 981, a storage unit 982, a communication I / F (interface) 983, an input / output I / F 984, and a media I / F 985. Here, the storage unit 982 includes a RAM 982a, a ROM 982b, and an HDD 982c. The communication I / F 983 is connected to the communication circuit 986. The input / output I / F 984 is connected to the input / output device 987. The media I / F 985 reads and writes data from and to the recording medium 988.

[0019] The ROM 982b stores a control program executed by the CPU, various data, etc. The CPU 981 realizes various functions by executing the application program read into the RAM 982a. The interior of the control device 50 shown in FIG. 1 earlier is shown as blocks of functions realized by an application program or the like. That is, as shown in FIG. 1, the control device 50 includes a charging time monitoring unit 52, a unit allocation unit 54, and a switching control unit 56.

[0020] The charging time monitoring unit 52 monitors the charging times T1 to T4 for each vehicle 42-1 to 42-4, that is, the elapsed time from the start time of charging. The unit allocation unit 54 determines the allocated unit numbers N1 to N4, which are the numbers of cell converter units 22 to be allocated to each vehicle 42-1 to 42-4. The switching control unit 56 sets the on / off states of the respective switches 34 in the matrix switch unit 30 so as to realize the determined allocated unit numbers N1 to N4.

[0021] FIG. 4 is a schematic diagram showing an example of a parking lot where the charging system 1 is installed. In FIG. 4, the parking lot 200 includes a ceiling 210 and a floor 220. The vehicle 42 described above is provided with a power receiving connector 42a and is parked on the floor 220 of the parking lot 200. The charging system 1 includes a substantially flat plate-shaped housing 106 along the shape of the ceiling 210 and is mounted on the ceiling 210 of the parking lot 200.

[0022] A cable 102 is attached to the charging system 1, and the cable 102 hangs downward. A power supply connector 104 is attached to the lower end of the cable 102. When the user fits the power supply connector 104 to the power receiving connector 42a and performs a predetermined operation, power is supplied from the charging system 1 to the vehicle 42, and the battery (not shown) of the vehicle 42 is charged. In this way, by mounting the charging system 1 on the ceiling 210 of the parking lot 200, the charging system 1 can be easily installed in the existing parking lot 200.

[0023] Figure 5 is a flowchart of the unit allocation routine. When a vehicle 42 is newly connected to any of the charging ports 40, the control device 50 activates this routine. In the following description, "m" and "k" are the port numbers of the charging ports 40. In the example shown in FIG. 1, they are any of "1" to "4". In particular, the port number k is the port number of the charging port 40-k to which the vehicle 42 is newly connected.

[0024] When the process proceeds to step S4 in FIG. 5, the charging time monitoring unit 52 determines whether there is a charging port 40-m for which the charging time Tm exceeds the predetermined time Tth. Here, the predetermined time Tth is, for example, the upper limit time of charging. If it is determined "Yes" in step S4, the process proceeds to step S6, and the unit allocation unit 54 releases the allocation of the cell converter unit 22 for the charging port 40-m. If it is determined "No" in step S4 or when the process of step S6 ends, the process proceeds to step S8.

[0025] In step S8, the unit allocation unit 54 determines whether there is an empty unit, that is, a unit among the cell converter units 22 that is not being used for charging. If it is determined "Yes" in step S8, the process proceeds to step S20. Here, the unit allocation unit 54 allocates an empty unit to the charging port 40-k, that is, the charging port to which the newly connected vehicle 42-k is connected. Next, when the process proceeds to step S26, charging starts for the newly connected vehicle 42-k from the charging port 40-k, and the process of this routine ends.

[0026] On the other hand, if there is no empty unit, it is determined "No" in step S8, and the process proceeds to step S10. In the following description, the number of cell converter units 22 assigned to the charging port 40-m is referred to as the assigned unit number Nm. Also, the power supplied from the charging port 40-m to the vehicle 42-m is referred to as the supply power Pm. Further, the rated power that one cell converter unit 22 can output is referred to as the unit rated power Pu.

[0027] In step S10, the unit assignment section 54 performs an integer division of the supply power Pm / the unit rated power Pu for the charging port 40-m for which the assigned unit number Nm is plural, and calculates the quotient Qm and the remainder Rm. Next, when the process proceeds to step S12, the unit assignment section 54 determines whether there is a charging port 40-m for which "Nm > Qm + 1". That is, it is determined whether there is a charging port 40-m for which the assigned unit number Nm is larger than necessary.

[0028] The reason why the assigned unit number Nm can become larger than necessary is that as the charging rate of the battery provided in the vehicle 42 increases, the charging current that can be supplied to the vehicle 42 decreases. That is, even if the assigned unit number Nm is a sufficient number at the start of charging, the assigned unit number Nm can become larger than necessary as the charging time elapses. When it is determined "Yes" in step S10, the process proceeds to step S22.

[0029] In step S22, the unit assignment section 54 reduces the assigned unit number Nm of the charging port 40-m to "Qm + 1". Even if the assigned unit number Nm is reduced in this way, the previous supply power Pm can be maintained. Further, the unit assignment section 54 assigns the empty unit generated as a result of reducing the assigned unit number Nm to the charging port 40-k to which the new vehicle 42-k is connected.

[0030] On the other hand, if it is determined "No" in step S12, the process proceeds to step S14. Here, the unit allocation unit 54 determines whether the minimum value of the surplus Rm is less than a predetermined value Rth. The predetermined value Rth is, for example, 1 / 2 of the unit rated power Pu. If it is determined "Yes" here, the process proceeds to step S24. In step S24, the unit allocation unit 54 reduces the number of allocated units Nm of the charging port 40-m with the minimum surplus Rm to the quotient Qm. Further, the unit allocation unit 54 allocates the resulting vacant units to the charging port 40-k to which the new vehicle 42-k is connected.

[0031] When the processing of step S22 or S24 described above is completed, the process proceeds to step S26. Here, as described above, charging is started for the newly connected vehicle 42-k from the charging port 40-k, and the processing of this routine is completed. On the other hand, if it is determined "No" in step S14, the process proceeds to step S16, and the process waits for a predetermined time. Thereafter, the process returns to step S4, and the same processing as described above is repeated.

[0032] Here, the significance of steps S14 and S24 will be described with a specific example. As an example, assume that the unit rated power Pu is 50 [kW], the supply power Pm at a certain charging port 40-m is 210 [kW], and the number of allocated units Nm is "5". In this case, the quotient Qm obtained in step S10 is "4", and the surplus Rm is "10 [kW]".

[0033] Assume that this surplus Rm = 10 [kW] is the minimum value among the surpluses R1 to R4 at all the charging ports 40-1 to 40-4 and is less than the predetermined value Rth. Then, in step S24, the number of allocated units Nm, which was originally "5", is reduced to the quotient Qm = 4. The maximum supply power Pm that can be achieved with the number of allocated units Nm = 4 is 4 × 50 [kW] = 200 [kW]. Therefore, the supply power Pm, which was originally 210 [kW], is reduced by the surplus Rm = 10 [kW] and becomes 200 [kW].

[0034] When the supply power Pm of the charging port 40-m is reduced, the charging time at the charging port 40-m becomes longer. However, when the surplus Rm, that is, the reduced power, is small, the influence can be suppressed to a relatively minor level. Therefore, in the above-described steps S14 and S24, the number of allocated units Nm is reduced for the charging port 40-m with the minimum surplus Rm.

[0035] [Effects of the Embodiment] As described above, according to the above-described embodiment, the charging system 1 includes a plurality of power conversion units (22), a plurality of charging ports 40 that supply power to a plurality of devices to be charged (42), a switch unit (30) that switches the connection relationship between the plurality of power conversion units (22) and the plurality of charging ports 40, a unit allocation unit 54 that allocates a power conversion unit (22) by a number of allocated units Nm, which is one or a plurality, to each device to be charged (42-m), and a switching control unit 56 that sets the connection relationship in the switch unit (30) according to the allocation result by the unit allocation unit 54. When a new device to be charged (42-k) is connected to any charging port (40-k), the unit allocation unit 54 preferentially reduces the number of allocated units Nm among the devices to be charged (42-m) having a plurality of allocated units Nm, for which the decrease in charging power is small when the number of allocated units Nm is reduced, and allocates the power conversion unit (22) in the free state generated by the reduction to the newly connected device to be charged (42-k). Thereby, since the number of allocated units Nm can be preferentially reduced for those with a small decrease in charging power (the smallest in the embodiment), it is possible to appropriately allocate the power conversion units (22) to all the devices to be charged (42) while suppressing the influence on the already charged devices to be charged (42-m).

[0036] Moreover, it is more preferable that the plurality of power conversion units (22) are connected in series to the AC power supply (16), and each converts the input AC voltage into a DC voltage and outputs it. Thereby, power can be directly received from the high-voltage AC system 16.

[0037] Further, it is more preferable that the unit allocation unit 54 further has a function of releasing the allocation of the power conversion unit (22) to the corresponding charging port 40 when there is a device to be charged (42) whose charging time Tm exceeds a predetermined time Tth. This enables more effective utilization of the power conversion unit (22).

[0038] Further, it is more preferable that the charging system 1 further includes a housing 106 attached to the ceiling 210 of the parking lot 200. This allows the charging system 1 to be easily installed in an existing parking lot 200.

[0039] [Modification Example] The present invention is not limited to the above-described embodiments, and various modifications are possible. The above-described embodiments are examples for easy understanding and explanation of the present invention, and are not necessarily limited to those having all the configurations described. Also, other configurations may be added to the configurations of the above embodiments, and a part of the configurations may be replaced with other configurations. Further, the control lines and information lines shown in the figures indicate those considered necessary for explanation, and do not necessarily show all the control lines and information lines required in the product. In practice, it may be considered that almost all the configurations are interconnected. Possible modifications to the above embodiments are, for example, as follows.

[0040] (1) In the above embodiment, an example in which the vehicle 42 is applied as an example of the device to be charged has been described. However, the device to be charged is not limited to the vehicle 42, and may be a moving body such as a ship or a flying object equipped with a battery, or an electric device.

[0041] (2) In the above embodiment, the charging system 1 received power from the AC power system 16. However, in recent years, DC power systems are also becoming more popular. Therefore, instead of the AC power system 16, the charging system 1 may be connected to a DC power source such as a DC power system. In this case, the AC / DC converter 71 and the smoothing capacitor 72 shown in FIG. 2 can be omitted inside the cell converter unit 22.

[0042] (3) Since the hardware of the control device 50 in the above embodiment can be realized by a general computer, a flowchart shown in FIG. 5, a program for executing various processes described above, etc. may be stored in a storage medium or distributed via a transmission line.

[0043] (4) The processes shown in FIG. 5 and other processes described above were described as software processes using a program in the above embodiment, but a part or all of them may be replaced with hardware processes using an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0044] (5) The various processes executed in the above embodiment may be executed by a server computer via a network (not shown), and various data stored in the above embodiment may also be stored in the server computer.

Explanation of Reference Numerals

[0045] 1 Charging system 16 AC system (AC power supply) 22 Cell converter unit (power conversion unit) 30 Matrix switch section (switch section) 40 Charging port 42 Vehicle (device to be charged) 50 Control device (control device for charging system) 54 Unit allocation section 56 Switching control section 106 Housing 200 Parking lot 210 Ceiling Nm Number of allocated units Tm Charging time Tth Predetermined time

Claims

1. A plurality of power conversion units; A plurality of charging ports for supplying power to a plurality of devices to be charged respectively; A switch unit for switching the connection relationship between the power conversion unit and the charging port; A unit allocation unit for allocating the power conversion unit to the charging port; A switching control unit for controlling the switch unit based on the result of the unit allocation unit allocating the power conversion unit to the charging port, comprising: When a device to be charged is connected to a certain charging port among the plurality of charging ports, the unit allocation unit allocates at least one power conversion unit from the plurality of power conversion units allocated to other charging ports to the charging port. A charging system characterized by the above.

2. When a device to be charged is connected to a certain charging port among the plurality of charging ports, the unit allocation unit allocates at least one power conversion unit from the plurality of power conversion units allocated to other charging ports to the charging port, among the plurality of other charging ports where the number of power conversion units is reduced, and the decrease in charging power is small. The charging system according to claim 1, characterized by the above.

3. When a device to be charged is connected to a certain charging port among the plurality of charging ports, the unit allocation unit allocates at least one power conversion unit from the plurality of power conversion units allocated to other charging ports to the charging port, among the plurality of other charging ports excluding the one with the smallest difference between the rated charging power by the allocated power conversion unit and the charging power required by the device to be charged connected to the other charging port. The charging system according to claim 1, characterized by the above.

4. When a device to be charged is connected to a certain charging port among the plurality of charging ports, the unit allocation unit allocates at least one power conversion unit from the plurality of power conversion units allocated to the other charging port with the largest difference between the rated charging power by the allocated power conversion unit and the charging power required by the device to be charged connected to the other charging port, among the plurality of other charging ports where the power conversion unit is allocated. The charging system according to claim 1, characterized in that...

5. When a charging target device is connected to a certain charging port among the plurality of charging ports, the unit allocation unit, among the plurality of other charging ports to which a plurality of power conversion units are allocated, allocates at least one power conversion unit from the plurality of power conversion units allocated to another charging port where the difference between the rated charging power by the allocated power conversion unit and the charging power required by the charging target device connected to the other charging port is greater than a predetermined value to the charging port. The charging system according to claim 1, characterized in that...

6. When a charging target device is connected to a certain charging port among the plurality of charging ports, the unit allocation unit, among the plurality of other charging ports to which a plurality of power conversion units are allocated, allocates at least one power conversion unit from the plurality of power conversion units allocated to another charging port where the difference between the total rated output power of the allocated power conversion unit and the total power output by the allocated power conversion unit is greater than the rated output power of the power conversion unit to the charging port. The charging system according to claim 1, characterized in that...

7. When a charging target device is connected to a certain charging port among the plurality of charging ports, the unit allocation unit divides the total power output by the allocated power conversion unit by the rated output power of the power conversion unit, uses the quotient as the required number of rated units, and allocates at least one power conversion unit from the plurality of power conversion units allocated to another charging port where the number of the allocated power conversion units is greater than the number obtained by adding 1 to the required number of rated units to the charging port. The charging system according to claim 1, characterized in that... **Claim 8**: When a charging target device is connected to a certain charging port among the plurality of charging ports, the unit allocation unit removes at least one of the power conversion units allocated to at least one of the other charging ports among the plurality of other charging ports to which a plurality of power conversion units are allocated, and the power output to the other charging ports is minimized. Allocate at least one of the power conversion units to the charging port. The charging system according to claim 1, characterized in that. **Claim 9**: When a charging target device is connected to a certain charging port among the plurality of charging ports, the unit allocation unit divides the total power output by the allocated power conversion unit among the plurality of other charging ports to which a plurality of power conversion units are allocated by the rated output power of the power conversion unit, and uses the remainder as the unit adjustment output. Allocate at least one of the power conversion units to the charging port when the unit adjustment output is smaller than a predetermined value. The charging system according to claim 1, characterized in that. **Claim 10**: When a charging target device is connected to a certain charging port among the plurality of charging ports, the unit allocation unit divides the total power output by the allocated power conversion unit among the plurality of other charging ports to which a plurality of power conversion units are allocated by the rated output power of the power conversion unit, and uses the remainder as the unit adjustment output. Allocate at least one of the power conversion units to the charging port when the unit adjustment output is the smallest. The charging system according to claim 1, characterized in that. **Claim 11** The plurality of power conversion units are connected in series to an AC power source, and each converts the input AC voltage into a DC voltage and outputs it. The charging system according to claim 1, characterized in that. **Claim 12** The unit allocation unit further has a function of releasing the allocation of the power conversion unit to the corresponding charging port when there is a charging target device whose charging time exceeds a predetermined time. The charging system according to claim 1, characterized in that. **Claim 13** It further includes a housing mounted on the ceiling of the parking lot. The charging system according to claim 1, characterized in that...

14. A plurality of power conversion units, A plurality of charging ports for supplying power to a plurality of devices to be charged respectively, A control device for a charging system applied to a charging system comprising a switch unit for switching the connection relationship between the power conversion unit and the charging port, A unit allocation unit for allocating the power conversion unit to the charging port, A switching control unit for controlling the switch unit based on the result of the unit allocation unit allocating the power conversion unit to the charging port, When a device to be charged is connected to a certain charging port among the plurality of charging ports, the unit allocation unit allocates at least one power conversion unit from the plurality of power conversion units allocated to other charging ports to the charging port The control device for a charging system, characterized in that...

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