Vehicle charging and discharging systems and electric vehicles
The system addresses the challenge of achieving convenience in electric vehicle charging and discharging systems by using a unidirectional rectifier and relay configuration to facilitate non-contact discharge with reduced costs and complexity.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- SUBARU CORP
- Filing Date
- 2022-07-29
- Publication Date
- 2026-05-27
AI Technical Summary
Existing vehicle charging and discharging systems for electric vehicles face challenges in achieving convenience with a simple configuration, particularly due to the complexity and cost associated with bidirectional inverters used for contactless charging and discharging.
A vehicle charging and discharging system for electric vehicles that includes a unidirectional rectifier, a relay on a second path between an inverter and a vehicle-side coil, and a control unit to manage the relay's state, allowing for non-contact discharge with a simpler configuration by using a unidirectional rectifier and a relay to control power flow.
Enables non-contact discharge with reduced costs and weight, achieving improved convenience and simplicity in system configuration by eliminating the need for a larger bidirectional inverter and unnecessary switching controls.
Smart Images
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Abstract
Description
Technical Field
[0001] The present disclosure relates to a vehicle charging and discharging system and an electric vehicle equipped with such a vehicle charging and discharging system.
Background Art
[0002] Various technologies have been disclosed as charging systems (vehicle charging systems) applied to electric vehicles (see, for example, Patent Document 1).
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 a charging and discharging system applied to an electric vehicle, for example, it is required to improve convenience with a simple configuration. It is desirable to provide a vehicle charging and discharging system capable of improving convenience with a simple configuration and an electric vehicle equipped with such a vehicle charging and discharging system.
Means for Solving the Problems
[0005] A vehicle charging and discharging system according to an embodiment of the present disclosure is a charging and discharging system applied to an electric vehicle, including a rectifier arranged on a charging path when non-contact charging a battery from an external device through a coil in the electric vehicle, an inverter arranged on a first path between the battery and a power output terminal for outputting the power stored in this battery, a relay arranged on a second path between the inverter and the coil, and a control unit for controlling the operating state of the relay so that the power stored in the battery is non-contact discharged to the external device via the inverter, the relay, and the coil on the second path, respectively.
[0006] An electric vehicle according to one embodiment of the present disclosure is equipped with a vehicle charging and discharging system according to the above embodiment of the present disclosure. [Brief explanation of the drawing]
[0007] [Figure 1] This is a block diagram showing a schematic configuration example of an electric vehicle, etc., according to one embodiment of the present disclosure. [Figure 2] This is a block diagram showing a schematic configuration example of an electric vehicle, etc., related to a comparative example. [Figure 3A] This flowchart illustrates an example of processing during discharge operations and other operations according to the embodiment. [Figure 3B] This flowchart shows an example of the process following Figure 3A. [Figure 4] These are block diagrams illustrating examples of operations during the processes shown in Figures 3A and 3B. [Figure 5] These block diagrams illustrate other operational examples during the processes shown in Figures 3A and 3B. [Figure 6] These block diagrams illustrate other operational examples during the processes shown in Figures 3A and 3B. [Modes for carrying out the invention]
[0008] The embodiments of this disclosure will be described in detail below with reference to the drawings. The description will be in the following order. 1. Embodiment (Example of a charging and discharging system that performs contactless charging and discharging with an electric vehicle) 2. Variations
[0009] <1. Embodiment> [composition] Figure 1 is a block diagram illustrating a schematic configuration example of an electric vehicle (electric vehicle 1) according to one embodiment of the present disclosure. This electric vehicle 1 is composed of an electric vehicle (EV) or a hybrid electric vehicle (HEV).
[0010] The electric vehicle 1 comprises a vehicle body 10, a battery 11, a vehicle-side coil 12, a rectifier 13, a power output terminal 14, an inverter 15, relays 161 and 162, a variable resistor element 17, and a control unit 18. In addition, as shown in Figure 1, an external facility 9 installed on the ground G and an equipment-side coil 92 electrically connected to the external facility 9 via an external cable R9 are provided in the vicinity of the electric vehicle 1. As will be described in detail later, the electric vehicle 1 is capable of both contactless charging and discharging via the vehicle-side coil 12 and the equipment-side coil 92 in connection with the external facility 9.
[0011] The rectifier 13, inverter 15, relay 162, variable resistor element 17, and control unit 18 correspond to a specific example of the "vehicle charging / discharging system" in this disclosure. The vehicle-side coil 12 corresponds to a specific example of the "coil in an electric vehicle" in this disclosure, and the relay 162 corresponds to a specific example of the "relay" in this disclosure.
[0012] The battery 11 stores the electricity used in the electric vehicle 1 and is composed of various types of secondary batteries, such as lithium-ion batteries. As will be described in more detail later, the electricity stored in this battery 11 can be discharged to external equipment 9 or supplied to external devices 8.
[0013] Here, the external equipment 9 is, for example, connected to the power grid and capable of contactless (wireless) charging and discharging with the electric vehicle 1. Specifically, as will be described in more detail later, contactless charging (contactless charging) is performed from the external equipment 9 to the electric vehicle 1, contactless discharge (contactless discharge) is performed from the electric vehicle 1 to the external equipment 9, and further discharge is performed from this external equipment 9 to the power grid, thereby achieving so-called V2G (Vehicle-to-Grid) operation. It is becoming a reality.
[0014] Further, the external device 8 is, for example, various household electrical appliances. Although details will be described later, power feeding from the electric vehicle 1 to the external device 8 enables the realization of so-called V2L (Vehicle-to-Load).
[0015] As shown in FIG. 1, the vehicle-side coil 12 is disposed, for example, below the vehicle body 10 in the electric vehicle 1. Specifically, the vehicle-side coil 12 is arranged to face the equipment-side coil 92 connected to the external equipment 9. As a result, although details will be described later, bidirectional non-contact power feeding is performed between the vehicle-side coil 12 and the equipment-side coil 92.
[0016] The rectifier 13 is disposed on the charging path Rc (see FIG. 1) when non-contact charging the battery 11 via the external cable R9, the equipment-side coil 92, and the vehicle-side coil 12 from the external equipment 9. Specifically, in the example of FIG. 1, the rectifier 13 is disposed between the vehicle-side coil 12 and a relay 161 (to be described later) on the charging path Rc. The rectifier 13 is a device that converts the AC power supplied by non-contact power feeding from the external equipment 9 side into DC power and outputs it to the battery 11 side. That is, the rectifier 13 performs one-way AC / DC conversion (rectification).
[0017] In FIG. 1 (and FIGS. 2, 4 to 6 to be described later), for the sake of convenience, among the paths connected among the external equipment 9, the equipment-side coil 92, inside the electric vehicle 1, and the external devices 8, the AC power path is indicated by a dashed line, and the DC power path is indicated by a solid line. However, for the above-described charging path Rc and the discharge paths Rd1, Rd2 and the power feeding path Rs to be described later, since they straddle such AC and DC paths, they are indicated by a dashed line as a whole for the sake of convenience.
[0018] The power output terminal 14 is a terminal (connector) for outputting the power stored in the battery 11 to the outside. Specifically, although details will be described later, the power stored in the battery 11 is output from the power output terminal 14 to the external device 8 via the inverter 15, so that power supply to the external device 8 is performed.
[0019] As shown in FIG. 1, the inverter 15 is arranged on the path R1 between the battery 11 and the power output terminal 14. This inverter 15 is a device that converts the DC power supplied from the battery 11 into AC power and outputs it (performs DC / AC conversion).
[0020] The relay 161 is arranged between the rectifier 13 and the battery 11 on the above-described charging path Rc. This relay 161 is configured to be mutually switchable between an ON state (connection state of the charging path Rc) and an OFF state (cut-off state of the charging path Rc) according to the control by the control unit 18 described later.
[0021] As shown in FIG. 1, the relay 162 is arranged on the path R2 between the inverter 15 and the vehicle-side coil 12. This relay 162 is also configured to be mutually switchable between an ON state (connection state of the path R2) and an OFF state (cut-off state of the path R2) according to the control by the control unit 18.
[0022] As shown in FIG. 1, the variable resistance element 17 is arranged between the relay 162 and the vehicle-side coil 12 on the above-described path R2. The resistance value Rv of this variable resistance element 17 is configured to change according to the control by the control unit 18, although details will be described later. That is, this resistance value Rv is a variable resistance value.
[0023] In addition, the above-described path R1 corresponds to a specific example of the "first path" in the present disclosure. Also, the above-described path R2 corresponds to a specific example of the "second path" in the present disclosure.
[0024] The control unit 18 controls various operations in the electric vehicle 1 (driving operation, charging and discharging operation of the battery 11, operation of various components, etc.) and performs various calculation processes. Specifically, the control unit 18 controls the operating state of relay 162, etc., so that the power stored in the battery 11 is discharged non-contact to the external equipment 9 via the inverter 15, relay 162, and vehicle-side coil 12 on path R2. The control unit 18 also controls the operating state of relay 162 and the resistance value Rv of variable resistor element 17, respectively, so that the power stored in the battery 11 is discharged non-contact to the external equipment via path R2, and power is supplied to the external device 8 from the power output terminal 14 via path R1. Furthermore, the control unit 18 sets the resistance value Rv of variable resistor element 17 so that, for example, when non-contact discharge to the external equipment 9 and power supply to the external device 8 are performed in parallel, power supply to the external device 8 is given priority over non-contact discharge to the external equipment 9.
[0025] Details of the control processing by the control unit 18 (relays 161, 162 and variable resistor element 17, etc.) will be described later (Figures 3A to 6).
[0026] Such a control unit 18 is configured to include, for example, one or more processors (CPU: Central Processing Unit) that execute a program, and one or more memories that are communicatively connected to these processors. Such memories are composed of, for example, RAM (Random Access Memory) for temporarily storing processing data, and ROM (Read Only Memory) for storing programs.
[0027] [Action and function / effect] Next, the operation, function, and effects of this embodiment will be described in detail, in comparison with the comparative example.
[0028] (A. Comparative example) Figure 2 is a block diagram showing a schematic configuration example of the electric vehicle (electric vehicle 101) etc. related to the comparative example described above. The electric vehicle 101 of this comparative example corresponds to the electric vehicle 1 of this embodiment shown in Figure 1, but with a bidirectional inverter (rectifier and inverter) 103 and a control unit 108 instead of the rectifier 13 and control unit 18, and without the relay 162 and variable resistor element 17. The other configurations are basically the same.
[0029] In this comparative example, the electric vehicle 101 is configured such that, according to various controls by the control unit 108, contactless charging and discharging are performed between the external equipment 9 and the battery 11 inside the electric vehicle 101 via the bidirectional inverter 103, and power is supplied from the battery 11 to the external equipment 8.
[0030] Specifically, contactless charging is performed from the external equipment 9 to the battery 11 via the equipment-side coil 92, the vehicle-side coil 12, the bidirectional inverter 103, and the relay 161 (see route R101 in Figure 2). In this case, the bidirectional inverter 103 performs AC / DC conversion (rectification) from AC power to DC power. Conversely, contactless discharge is performed from the battery 11 to the external equipment 9 via the relay 161, the bidirectional inverter 103, the vehicle-side coil 12, and the equipment-side coil 92 (see route R101 in Figure 2). In this case, the bidirectional inverter 103 performs DC / AC conversion from DC power to AC power. Furthermore, in the electric vehicle 101, power is supplied from the battery 11 to the external equipment 8 via the inverter 15 and the power output terminal 14 (see route R102 in Figure 2). In this comparative example, in addition to conventional contactless charging, contactless discharge to external equipment 9 and power supply to external devices 8 are also performed, resulting in the realization of so-called V2G and V2L, and thus improving convenience.
[0031] However, in this comparative example, as described above, contactless charging and discharging is performed via the bidirectional inverter 103, which results in the following compared to the case where a unidirectional rectifier 13 is provided as in this embodiment. In other words, the bidirectional inverter 103 is larger than the rectifier 13, which has a greater impact on cost and weight. Also, in the case of the bidirectional inverter 103, as described above, in addition to rectification (AC / DC conversion) similar to that of the rectifier 13, reverse DC / AC conversion is also performed, so new switching control for DC / AC conversion is required. For these reasons, it can be said that it is difficult to improve convenience with a simple configuration in this comparative example.
[0032] (B. This embodiment) In contrast, the electric vehicle 1 of this embodiment is provided with a unidirectional rectifier 13 on the aforementioned charging path Rc, a relay 162 on the path R2 between the inverter 15 and the vehicle-side coil 12, and a control unit 18 that controls the operating state of the relay 162, etc. Thus, in this embodiment, in addition to contactless charging of the battery 11, contactless discharge to the external equipment 9 and power supply to the external device 8 are realized by the methods described in detail below.
[0033] (Examples of processing during discharge operations, etc.) In the following, with reference to Figure 1, as well as Figures 3A, 3B, and Figures 4 to 6, we will describe in detail the processing examples (control processing examples by the control unit 18, etc.) during the discharge operation (the non-contact discharge and power supply operations described above) according to this embodiment.
[0034] Figures 3A and 3B are flowcharts illustrating examples of the processes involved in the discharge operation and other operations according to this embodiment. Figures 4 to 6 are block diagrams illustrating examples of the operations involved in the processes shown in Figures 3A and 3B.
[0035] In the series of processing examples shown in Figures 3A and 3B, first, the control unit 18 determines whether or not the electric vehicle 1 is stopped (step S11 in Figure 3A). If it is determined that the electric vehicle 1 is not stopped (is running) (step S11:N), the determination in step S11 is performed again.
[0036] On the other hand, if it is determined that the electric vehicle 1 is stopped, as shown in Figure 4 (step S11:Y), the process proceeds to step S12. In Figure 4 (initial state while stopped), both relays 161 and 162 are set to the OFF state (shut-off state). In the examples of Figures 4 to 6 described below, relay 161 is assumed to remain in the OFF state.
[0037] In step S12 described above, the control unit 18 determines whether or not to perform contactless discharge to the external equipment 9 in response to, for example, an operation instruction from the user of the electric vehicle 1. If it is determined that no such contactless discharge will be performed (step S12:N), the control unit 18 maintains the OFF state in the relay 162 (step S13). In this case, the series of processing examples shown in Figures 3A and 3B then end.
[0038] On the other hand, if it is determined that the above-mentioned non-contact discharge is to be performed (step S12:Y), the control unit 18 then determines whether or not the inverter 15 is in an operating state (step S14). If it is determined that the inverter 15 is not in an operating state (is in a stopped state) (step S14:N), the control unit 18 sets the inverter 15 to an operating state (step S15 in Figure 3B) and proceeds to step S16, which will be described below.
[0039] On the other hand, if it is determined that the inverter 15 is operating (step S14:Y), the control unit 18 then determines whether or not to supply power to the external device 8 in response to, for example, an operation instruction from the user of the electric vehicle 1 (step S16). If it is determined that power should be supplied to such an external device 8 (step S16:Y), the process proceeds to step S23 (Figure 3B) and subsequent steps, which will be described later.
[0040] On the other hand, if it is determined that power should not be supplied to the external device 8 (step S16:N), the control unit 18 then sets the relay 162 to the ON state (connected state) if it is currently in the OFF state (step S17). At this time, the resistance value Rv of the variable resistor element 17 is set to Rv ≈ 0. Subsequently, the control unit 18 performs a non-contact discharge to the external equipment 9 via the aforementioned path R2, as shown in the discharge path Rd1 in Figure 5, for example (step S18).
[0041] Next, the control unit 18 determines whether or not to supply power to the external device 8 again (step S19). If it is determined that power should be supplied to the external device 8 (step S19:Y), the control unit 18 sets the relay 162 to the OFF state (step S20 in Figure 3B) and proceeds to step S23 (Figure 3B) and subsequent steps, which will be described later.
[0042] On the other hand, if it is determined that power will not be supplied to the external device 8 (step S19:N), the control unit 18 then determines whether or not to terminate the contactless discharge to the external equipment 9, for example, in response to an operation instruction from the user of the electric vehicle 1 (step S21). If it is determined that the contactless discharge will not be terminated (step S21:N), the process returns to step S19 described above.
[0043] On the other hand, if it is determined that the non-contact discharge should be terminated (step S21:Y), the control unit 18 sets the relay 162 to the OFF state and sets the inverter to the stopped state (step S22). In this case, the series of processes shown in Figures 3A and 3B are then completed.
[0044] In step S23 (Figure 3B) described above, the control unit 18 monitors the amount of power supplied to the external device 8 Ps using calculation processing, etc. For example, if the external device 8 is not connected to the power output terminal 14 or if the operation of the external device 8 has stopped, the amount of power supplied Ps is calculated as 0.
[0045] Next, the control unit 18 sets the resistance value Rv (Rv>0) of the variable resistor element 17 according to the magnitude of the monitored power supply amount Ps (step S24). Subsequently, if the relay 162 is in the OFF state, the control unit 18 sets it to the ON state (step S25).
[0046] Next, the control unit 18 performs a non-contact discharge to the external equipment 9 via the aforementioned path R2, as shown in the discharge path Rd2 in Figure 6 (step S26). At the same time, power is supplied to the external device 8 via the aforementioned path R1, as shown in the power supply path Rs in Figure 6. Here, the discharge power amount Pd at this time is the difference in power obtained by subtracting the power supplied to the external device 8 Ps from the power supplied (output) amount Pin from the inverter 15. In other words, the discharge power amount Pd at this time is set to such a difference in power (Pd = Pin - Ps).
[0047] Next, the control unit 18 determines whether or not to supply power to the external device 8 again (step S27). If it is determined that power should not be supplied to the external device 8 (step S27:N), the process proceeds to step S17 (Figure 3A) as described above.
[0048] On the other hand, if it is determined that power should be supplied to the external device 8 (step S27:Y), the control unit 18 then determines whether or not to terminate the contactless discharge to the external equipment 9, for example, in response to an operation instruction from the user of the electric vehicle 1 (step S28). If it is determined that the contactless discharge should not be terminated (step S28:N), the process returns to step S23 described above.
[0049] On the other hand, if it is determined that the non-contact discharge should be terminated (step S28:Y), the control unit 18 sets the relay 162 to the OFF state (step S29). In this case, the series of processes shown in Figures 3A and 3B are then completed.
[0050] This concludes the explanation of the series of processing examples shown in Figures 3A and 3B.
[0051] (C. Action / Effect) In this embodiment, the electric vehicle 1 is provided with a unidirectional rectifier 13 on the charging path Rc and a relay 162 on the path R2 between the inverter 15 and the vehicle-side coil 12. The operation state of the relay 162 is controlled so that the power stored in the battery 11 inside the electric vehicle 1 is discharged non-contact to the external equipment 9 via the inverter 15, relay 162, and vehicle-side coil 12 on the path R2, respectively.
[0052] As a result, in this embodiment, non-contact discharge from the battery 11 to the external equipment 9 can be achieved with a simpler configuration compared to, for example, the case in the comparative example above where a bidirectional inverter 103 is provided instead of a unidirectional rectifier 13. In other words, compared to the case of such a bidirectional inverter 103, the rectifier 13 can be made smaller, and costs and weight can be reduced, and new switching control for DC / AC conversion is not required, so non-contact discharge can be achieved with a general-purpose configuration. As a result, in this embodiment, convenience can be improved with a simpler configuration compared to the comparative example above.
[0053] Furthermore, in this embodiment, the operating state of the relay 162 and the resistance value Rv of the variable resistor element 17 are controlled so that non-contact discharge is performed to the external equipment 9 as described above, and power is supplied to the external device 8 from the power output terminal 14 via the path R1. This results in the following: In other words, such control enables non-contact discharge to the external equipment 9 and power supply to the external device 8 to be achieved with a simple configuration. As a result, convenience can be further improved with a simple configuration.
[0054] Furthermore, in this embodiment, the resistance value Rv of the variable resistor element 17 is set so that power supply to the external device 8 is given priority over non-contact discharge to the external equipment 9, as follows: When both non-contact discharge to the external equipment 9 and power supply to the external device 8 are performed, priority power supply to the external device 8 can be easily achieved according to the setting of such resistance value Rv. As a result, it becomes possible to further improve convenience with a simple configuration.
[0055] <2. Variant> Although the present disclosure has been described above with reference to embodiments, the present disclosure is not limited to these embodiments, and various modifications are possible.
[0056] For example, the configuration (type, shape, arrangement, number, etc.) of each component in the electric vehicle 1, etc., is not limited to those described in the above embodiment. That is, the configuration of each of these components may be of a different type, shape, arrangement, number, etc. Also, the values, ranges, magnitudes, etc. of the various parameters described in the above embodiment are not limited to those described in the above embodiment, and may be of a different value, range, magnitude, etc.
[0057] Specifically, in the above embodiment, for example, an example was described in which a variable resistor element 17 is placed on the path R2 between the inverter 15 and the vehicle-side coil 12. However, in some cases, such a variable resistor element 17 may not be provided. Also, in some cases, a semiconductor switch or the like that can reduce resistance loss may be provided instead of such a variable resistor element 17.
[0058] Furthermore, although the above embodiment specifically described an example of processing during charging and discharging operations (such as an example of control processing by the control unit 18), it is not limited to this example. That is, for example, other methods may be used to perform processing during charging and discharging operations. Specifically, for example, in some cases, the power supply process from the electric vehicle 1 to the external device 8 may be prevented.
[0059] Furthermore, the series of processes described in the above embodiment may be performed by hardware (circuits) or by software (programs). If performed by software, the software consists of a group of programs that cause the computer to execute each function. Each program may, for example, be pre-installed in the computer or installed on the computer from a network or recording medium.
[0060] In addition, the various examples described so far may be applied in any combination.
[0061] Furthermore, the effects described herein are merely illustrative and not limiting, and other effects may also occur. [Explanation of Symbols]
[0062] 1...Electric vehicle, 10...Vehicle body, 11...Battery, 12...Vehicle-side coil, 13...Rectifier, 14...Power output terminal, 15...Inverter, 161,162...Relay, 17...Variable resistor element, 18...Control unit, 8...External equipment, 9...External equipment, 92...Equipment-side coil, R1,R2...Path, R9...External cable, Rc...Charging path, Rd1,Rd2...Discharge path, Rs...Power supply path, Rv...Resistance value, Pin...Power supplied, Pd...Power discharged, Ps...Power supplied, G...Ground.
Claims
1. A charging and discharging system applicable to electric vehicles, A rectifier positioned on the charging path when contactlessly charging the battery from an external device via a coil inside the electric vehicle, An inverter is arranged on a first path between the battery and a power output terminal for outputting the power stored in the battery, A relay is arranged on the second path between the inverter and the coil, A control unit controls the operating state of the relay so that the power stored in the battery is discharged non-contact to the external equipment via the inverter, relay, and coil on the second path, respectively. A vehicle charging and discharging system equipped with the following features.
2. A variable resistor element is further provided on the second path, The control unit, The power stored in the battery is discharged non-contact to the external equipment via the second path, and power is supplied to the external device from the power output terminal via the first path. The operating state of the relay and the resistance value of the variable resistor element are controlled, respectively. The vehicle charging and discharging system according to claim 1.
3. The control unit, Compared to non-contact discharge to the external equipment, power supply to the external device is given priority. The resistance value of the variable resistor element is set. The vehicle charging and discharging system according to claim 2.
4. The control unit, The difference in power obtained by subtracting the amount of power supplied to the external equipment from the amount of power supplied from the inverter is set as the amount of discharged power during non-contact discharge to the external equipment, The resistance value of the variable resistor element is set according to the magnitude of the power supply amount. The vehicle charging and discharging system according to claim 2 or claim 3.
5. Equipped with a vehicle charging and discharging system applicable to electric vehicles, The aforementioned vehicle charging and discharging system is A rectifier positioned on the charging path when contactlessly charging the battery from an external device via a coil inside the electric vehicle, An inverter is arranged on a first path between the battery and a power output terminal for outputting the power stored in the battery, A relay is arranged on the second path between the inverter and the coil, A control unit controls the operating state of the relay so that the power stored in the battery is discharged non-contact to the external equipment via the inverter, relay, and coil on the second path, respectively. A sharp electric vehicle.