Charging system

Abstract

To provide a charging system capable of preventing a charging connector from becoming unable to be detached from a charging inlet due to freezing while suppressing an increase in cost.SOLUTION: A charging system according to the present invention that charges a battery mounted on a vehicle by fitting a charging connector of a charging device into a charging inlet of the vehicle includes: temperature detection means that detects a temperature of the charging inlet; usage start time acquisition means that acquires a usage start time at which a user starts using the vehicle; and control means that executes control to perform charging by flowing a larger current than before immediately before the usage start time when the charging inlet temperature is lower than a preset threshold temperature on the basis of a detection result of the temperature detection means at the time of charging the battery by mating the charging inlet and charging connector.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a charging system. [Background technology]

[0002] Patent Document 1 discloses a technology in which a heating mechanism is added to the charging connector of a charging device, and when the charging connector connected to a vehicle's charging inlet freezes and becomes unable to be removed at low temperatures, power is supplied to the heating mechanism to prevent the charging connector from freezing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-167003 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology disclosed in Patent Document 1 requires a separate heating mechanism for heating the charging connector, which leads to increased costs.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a charging system that can prevent freezing and the inability to detach a charging connector from a charging inlet while suppressing increases in costs. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the charging system of the present invention is a charging system that charges a battery installed in a vehicle by engaging a charging connector of a charging device with a charging inlet of the vehicle, and is characterized by comprising: a temperature detection means for detecting the temperature of the charging inlet; a usage start time acquisition means for acquiring the usage start time when the user starts using the vehicle; and a control means that, when the charging inlet and the charging connector are engaged to charge the battery, if the temperature of the charging inlet is lower than a predetermined threshold temperature based on the detection result of the temperature detection means, executes control to flow a larger current than before to charge the battery just before the usage start time.

[0007] This increases the amount of heat generated by the resistance to current flow in the charging inlet and charging connector at low temperatures, making it possible to prevent the mating portion between the charging inlet and charging connector from freezing, thereby preventing the charging connector from freezing and becoming unable to be detached from the charging inlet, while minimizing the cost increase that would be caused by adding a separate heating mechanism to the charging connector.

[0008] In the above configuration, when the temperature of the charging inlet is lower than a preset threshold temperature, the control means may increase the charging current as the time from the start of charging approaches the usage start time.

[0009] This makes it possible to prevent the charging inlet and the charging connector from freezing before the start time of use.

[0010] Furthermore, the charging system of the present invention is a charging system that charges a battery mounted on a vehicle by fitting a charging connector of a charging device to a charging inlet of the vehicle, and is characterized in that it includes: control means that fits the charging inlet and the charging connector to charge the battery, starts to detach the charging connector from the charging inlet after charging of the battery is completed, and, if the charging connector cannot be detached from the charging inlet, executes control that alternately and repeatedly performs discharging, in which current flows from the charging inlet side to the charging connector side, and charging, in which current flows from the charging connector side to the charging inlet side.

[0011] This allows for repeated alternating charging and discharging, increasing the amount of heat generated by the resistance to current flow in the charging inlet and charging connector, thereby preventing the mating portion between the charging inlet and charging connector from freezing, thereby preventing the charging connector from freezing and becoming unable to be detached from the charging inlet, while minimizing the cost increase that would be caused by adding a separate heating mechanism to the charging connector.

[0012] In the above invention, a portion of the charging connector may be made of a highly thermally conductive material.

[0013] This makes it possible to easily transfer a large amount of heat generated by the current flow resistance to the mating portion between the charging inlet and the charging connector.

[0014] In the above invention, the charging device may be provided with an arm mechanism that holds the charging connector and automatically connects and disconnects the charging connector from the charging inlet.

[0015] This prevents the mating portion between the charging inlet and the charging connector from freezing even at low temperatures, and allows the charging connector to be automatically detached from the charging inlet. [Effects of the Invention]

[0016] The charging system of the present invention increases the amount of heat generated by the resistance to current flow in the charging inlet and charging connector at low temperatures, thereby preventing the mating portion between the charging inlet and charging connector from freezing, thereby preventing the charging connector from becoming unable to be detached from the charging inlet due to freezing, while minimizing the cost increase that would be caused by adding a separate heating mechanism to the charging connector. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a block diagram showing the configuration of a charging system according to an embodiment. [Figure 2] FIG. 2 is a flowchart showing an example of the flow of the charge control process performed by the charge control unit. [Figure 3] FIG. 3 is a diagram showing an example of a low-temperature charging profile. [Figure 4] FIG. 4 is a diagram showing an example of a room temperature charging profile. [Figure 5] FIG. 5 is a flowchart showing another example of the flow of the charge control process performed by the charge control unit. [Figure 6] FIG. 6 is an explanatory diagram of freeze avoidance charging and discharging. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of a charging system according to the present invention will be described, but the present invention is not limited to the embodiment.

[0019] Fig. 1 is a block diagram showing the configuration of a charging system 1 according to an embodiment. As shown in Fig. 1, the charging system 1 according to the embodiment is a system for charging a battery 21 mounted on a vehicle 2 such as an electric vehicle by connecting a charging connector 33 of a charging device 3 installed outside the vehicle 2 to a charging inlet 25 of the vehicle 2.

[0020] In this charging system 1, a battery 21, a charging control unit 22, a temperature detection unit 23, a usage start time acquisition unit 24, and a charging inlet 25 are provided on the vehicle 2 side. However, depending on the type of vehicle 2, the temperature detection unit 23 and the usage start time acquisition unit 24 may not be provided.

[0021] The battery 21 is configured by, for example, a nickel-metal hydride battery or a lithium-ion battery, and is a battery that stores high-voltage DC power for driving the vehicle 2.

[0022] The charging control unit 22 is configured by an electronic circuit mainly consisting of a well-known microcomputer including a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), an input / output interface, etc. The charging control unit 22 cooperates with a charging control unit 31 provided on the charging device 3 side to control the charging process of charging the battery 21 using the charging device 3. The charging control unit 22 also acquires information about the SOC (State Of Charge) of the battery 21 via an in-vehicle network such as a CAN (Controller Area Network).

[0023] Temperature detection unit 23 is configured by a temperature sensor mounted on charging inlet 25. Temperature detection unit 23 detects temperature T of charging inlet 25 and outputs an electrical signal indicating the detected temperature T of charging inlet 25 to charging control unit 22.

[0024] The usage start time acquisition unit 24 acquires the usage start time when the user starts using the vehicle 2. For example, the usage start time acquisition unit 24 acquires the usage start time input by the user using a communication terminal owned by the user or an input device mounted on the vehicle 2, by communicating with the communication terminal, the input device, or the like.

[0025] The charging inlet 25 is configured by providing a current-carrying terminal inside a housing having a hole formed therein into which the charging connector 33 of the charging device 3 is inserted.

[0026] On the other hand, the charging device 3 is provided with a charging control unit 31, a storage unit 32, and a charging connector 33.

[0027] The charging control unit 31 is configured with an electronic circuit mainly including a microcomputer similar to that of the charging control unit 22. The charging control unit 31 cooperates with the charging control unit 22 on the vehicle 2 side to control the charging process for charging the battery 21 via the charging connector 33 and the charging inlet 25. The charging control unit 31 also communicates with the charging control unit 22 to acquire various information such as the temperature T of the charging inlet 25 detected by the temperature detection unit 23, the usage start time acquired by the usage start time acquisition unit 24, and information related to the SOC of the battery 21.

[0028] Furthermore, when charging connector 33 and charging inlet 25 are mated and electrically connected, charging control unit 31 acquires a mating signal indicating the mated state from charging control unit 22 of vehicle 2 via charging inlet 25 and charging connector 33, and determines that charging connector 33 and charging inlet 25 are mated. At this time, charging control unit 31 detects that mating of charging connector 33 and charging inlet 25 has started when the mating signal is first acquired, and then detects that mating of charging connector 33 and charging inlet 25 has been completed when the mating signal is continuously acquired for a certain period of time. On the other hand, when the mating signal is no longer acquired, charging control unit 31 determines that charging connector 33 has been detached from charging inlet 25 and that the mating of charging connector 33 and charging inlet 25 has been released (disconnected state). At this time, charging control unit 31 detects that detachment of charging connector 33 from charging inlet 25 has started when the mating signal is not acquired for the first time, and then detects that detachment of charging connector 33 from charging inlet 25 has been completed when the mating signal is not acquired continuously for a certain period of time. Note that the method for determining whether charging connector 33 and charging inlet 25 are mated or not, and the method for detecting that mating has started, mating has been completed, detachment has started, and detachment has been completed are not particularly limited, and known techniques can be adopted.

[0029] The storage unit 32 stores information used when the charge control unit 31 performs charge control, such as a room temperature charge profile and a low temperature charge profile.

[0030] Charging connector 33 is composed of a current-carrying terminal that is electrically connected to the current-carrying terminal of charging inlet 25 when inserted into charging inlet 25 of vehicle 2, and a holding portion that holds the current-carrying terminal. The holding portion of charging connector 33 is made of a highly thermally conductive material, such as a resin material that has relatively high thermal conductivity.

[0031] In the charging system 1 having such a configuration, the charging control unit 31 on the charging device 3 side executes the charging control process described below to charge the battery 21 while avoiding freezing of the charging connector 33. The operation of the charging control unit 31 when executing the charging control process will be described below.

[0032] 2 is a flowchart showing an example of the flow of the charge control process performed by the charge control unit 31. First, the charge control unit 31 detects that the charging connector 33 of the charging device 3 has started to be mated with the charging inlet 25 of the vehicle 2 (step S1). Next, the charge control unit 31 detects that the mating of the charging connector 33 of the charging device 3 with the charging inlet 25 of the vehicle 2 has been completed (step S2). Next, the charge control unit 31 starts charging (step S3). Next, the charge control unit 31 determines whether the temperature T of the charging inlet 25 detected by the temperature detection unit 23 is lower than a preset threshold temperature T0 (step S4). Note that the threshold temperature T0 is set to a low temperature below which the charging connector 33 and the charging inlet 25 may freeze.

[0033] When the charging control unit 31 determines that the temperature T of the charging inlet 25 is lower than the threshold temperature T0 (Yes in step S4), the charging control unit 31 acquires the usage start time at which the user starts using the vehicle 2 from the usage start time acquisition unit 24 (step S5). Note that the usage start time at which the user starts using the vehicle 2 is the departure time at which the user gets into the vehicle 2 and departs. Next, the charging control unit 31 performs charging using the low-temperature charging profile stored in the memory unit 32 (step S6).

[0034] FIG. 3 is a diagram showing an example of a low-temperature charging profile. In charging using the low-temperature charging profile, the battery 21 is charged by supplying a current so that the battery 21 is fully charged by the acquired departure time (use start time). In this case, as shown in FIG. 3, the charging control unit 31 gradually increases the current from the start of charging as the departure time (use start time) approaches, and in the latter half of charging, just before the departure time (use start time), the charging control unit 31 supplies a current that is larger than before, the largest current (high current) set in the low-temperature charging profile, to charge the battery. Then, after charging using the low-temperature charging profile, the charging control unit 31 proceeds to the processing of step S8.

[0035] On the other hand, if, in the process of step S4, charge control unit 31 determines that temperature T of charge inlet 25 is equal to or higher than threshold temperature T0 (No in step S4), charge is performed using the room temperature charge profile (step S7).

[0036] Fig. 4 is a diagram showing an example of a room temperature charging profile. In charging using the room temperature charging profile, the battery 21 is charged by passing a current so that the battery 21 is fully charged as soon as possible after the start of charging. In this case, as shown in Fig. 4, the charging control unit 31 passes the largest current (high current) set in the room temperature charging profile from the start of charging, gradually reduces the current as the battery 21 approaches full charge, and passes a low current in the latter half of charging. Then, after performing charging using the room temperature charging profile, the charging control unit 31 proceeds to the processing of step S8.

[0037] The charging control unit 31 performs charging using the low temperature charging profile or the normal temperature charging profile, and determines that the battery 21 is fully charged based on information related to the SOC of the battery 21 (step S8). Next, the charging control unit 31 detects that removal of the charging connector 33 of the charging device 3 from the charging inlet 25 of the vehicle 2 has started (step S9). Next, the charging control unit 31 detects that removal of the charging connector 33 of the charging device 3 from the charging inlet 25 of the vehicle 2 has been completed (step S10). Then, the charging control unit 31 ends the example charging control process.

[0038] In the charging system 1 according to the embodiment, at the start of charging, the temperature detector 23 mounted on the vehicle 2 detects the temperature T of the charging inlet 25. The detected temperature T is compared with a threshold temperature T0 to determine whether the mating portion between the charging inlet 25 and the charging connector 33 is likely to freeze. If the temperature T is less than the threshold temperature T0, the time when the user's use of the vehicle 2 begins, such as a departure time, is acquired, and charging using a low-temperature profile is then performed. In charging using this low-temperature charging profile, a high current is applied immediately before the start of use (departure time). This allows for a greater amount of heat generation due to current flow resistance in the charging inlet 25 and the charging connector 33 than in charging using a room-temperature charging profile, in which a low current is applied in the latter half of charging. In particular, in the charging system 1 according to the embodiment, a portion (a holding portion) of the charging connector 33 is made of a highly thermally conductive material, which allows for a greater amount of heat generated due to current flow resistance to be easily transferred to the mating portion between the charging inlet 25 and the charging connector 33.

[0039] As a result, in the charging system 1 according to the embodiment, the amount of heat generated by the current-flow resistance in the charging inlet 25 and the charging connector 33 can be increased without adding a heating mechanism to the charging connector 33, and the mating portion between the charging inlet 25 and the charging connector 33 can be heated and prevented from freezing by the time of start of use (departure time) even at low temperatures. Therefore, in the charging system 1 according to the embodiment, it is possible to prevent the charging connector 33 from becoming unable to be detached from the charging inlet 25 due to freezing, while suppressing an increase in costs.

[0040] 5 is a flowchart showing another example of the flow of the charging control process performed by the charging control unit 31. First, the charging control unit 31 detects that the charging connector 33 of the charging device 3 has started to be mated with the charging inlet 25 of the vehicle 2 (step S11). Next, the charging control unit 31 detects that the mating of the charging connector 33 of the charging device 3 with the charging inlet 25 of the vehicle 2 has been completed (step S12). Next, the charging control unit 31 starts charging (step S13). Based on information about the SOC of the battery 21, the charging control unit 31 determines that the battery 21 is fully charged (step S14). Next, the charging control unit 31 detects that the disconnection of the charging connector 33 of the charging device 3 from the charging inlet 25 of the vehicle 2 has started (step S15). Next, the charging control unit 31 determines whether the disconnection of the charging connector 33 of the charging device 3 from the charging inlet 25 of the vehicle 2 has been completed (step S16). If charging control unit 31 determines that the removal of charging connector 33 from charging inlet 25 is complete (Yes in step S16), it ends the series of charging control processes. On the other hand, if charging control unit 31 determines that the removal of charging connector 33 from charging inlet 25 is not complete (No in step S16), it determines that charging connector 33 and charging inlet 25 are frozen, and performs freeze avoidance charging and discharging (step S17).

[0041] This freeze avoidance charge / discharge is performed after the charging control unit 31 determines that the removal of the charging connector 33 from the charging inlet 25 has not been completed (removal NG). As shown in FIG. 6, this involves alternately repeating discharging, which flows current from the charging inlet 25 to the charging connector 33 (from the battery 21 of the vehicle 2 to the charging device 3), and charging, which flows current from the charging connector 33 to the charging inlet 25 (from the charging device 3 to the battery 21 of the vehicle 2), so as to balance the power balance. This prevents the SOC of the battery 21 from being kept within a predetermined range and prevents the mating portion between the charging inlet 25 and the charging connector 33 from freezing due to heat generation caused by current resistance in the charging inlet 25 and the charging connector 33.

[0042] Thereafter, after performing freeze avoidance charge and discharge for a certain period of time, the process proceeds to step S16, where freeze avoidance charge and discharge are repeatedly performed until it is determined that the disconnection of charging connector 33 from charging inlet 25 is complete. Then, when charging control unit 31 determines that the disconnection of charging connector 33 from charging inlet 25 is complete (Yes in step S16), it ends the series of charge and discharge control processes.

[0043] In charging system 1 according to the embodiment, if charging connector 33 cannot be detached from charging inlet 25 when charging is completed, it is determined that charging connector 33 and charging inlet 25 are frozen, and charging and discharging are performed to balance the power balance, and current is passed between charging inlet 25 and charging connector 33. As a result, in charging system 1 according to the embodiment, the amount of heat generated by current flow resistance in charging inlet 25 and charging connector 33 is increased even at low temperatures, without adding a separate heating mechanism to charging connector 33, thereby preventing freezing of the mating portion between charging inlet 25 and charging connector 33 and enabling charging connector 33 to be detached from charging inlet 25.

[0044] Note that the charging system 1 according to the embodiment is not limited to a system in which the insertion and removal (engagement and removal) of the charging connector 33 of the charging device 3 into and from the charging inlet 25 of the vehicle 2 is performed manually by the user. For example, an automatic charging device capable of automatic charging may be employed, in which the charging device 3 is provided with an arm mechanism that holds the charging connector 33 and automatically inserts and removes (engages and removes) the charging connector 33 into and from the charging inlet 25. In this way, when the battery 21 of the vehicle 2 is charged by the automatic charging device, the amount of heat generated by current flow resistance in the charging inlet 25 and the charging connector 33 can be increased, preventing freezing of the engagement between the charging inlet 25 and the charging connector 33 even at low temperatures, and allowing the charging connector 33 to be automatically detached from the charging inlet 25.

[0045] When an automatic charging device is used, in addition to the above-described methods, it is also possible to determine whether charging connector 33 and charging inlet 25 are mated, and to detect that mating has started, that mating has been completed, and that disengagement has started and been completed, based on, for example, the operating state of the arm mechanism. For example, the time when the arm mechanism holds charging connector 33 and starts the operation of inserting charging connector 33 into charging inlet 25 can be detected as the time when mating between charging connector 33 and charging inlet 25 has started. [Explanation of symbols]

[0046] 1 Charging System 2 vehicles 3 Charging device 21 Battery 22 Charging control unit 23 Temperature detection unit 24 Usage start time acquisition part 25 Charging inlet 31 Charging control unit 32 Storage section 33 Charging connector

Claims

1. A charging system that charges a battery mounted on a vehicle by fitting a charging connector of a charging device into a charging inlet of the vehicle, a temperature detection means for detecting the temperature of the charging inlet; a usage start time acquisition means for acquiring a usage start time when the user starts using the vehicle; a control means for controlling the charging of the battery by passing a current larger than that used up until the start of use immediately before the start of use when the temperature of the charging inlet is lower than a predetermined threshold temperature based on the detection result of the temperature detection means when the charging inlet and the charging connector are mated to charge the battery; It is equipped with The control means is capable of executing control to alternately repeat discharging, which causes a current to flow from the charging inlet to the charging connector, and charging, which causes a current to flow from the charging connector to the charging inlet, so as to balance the power balance, by engaging the charging inlet with the charging connector and starting to detach the charging connector from the charging inlet after charging of the battery is completed, and, if the charging connector cannot be detached from the charging inlet, by alternately repeating discharging, which causes a current to flow from the charging inlet to the charging connector, and charging, which causes a current to flow from the charging connector to the charging inlet, so as to balance the power balance. A charging system characterized by:

2. 2. The charging system according to claim 1, wherein the control means increases the charging current as the usage start time approaches from the start of charging when the temperature of the charging inlet is lower than a preset threshold temperature.

3. 3. The charging system according to claim 1, wherein a part of the charging connector is made of a highly thermally conductive material.

4. 3. The charging system according to claim 1, wherein the charging device is provided with an arm mechanism that holds the charging connector and automatically inserts and removes the charging connector from the charging inlet.

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