Charging system

Abstract

A charging system makes a charging connector of a charging device fit in a charging port of a vehicle to charge a battery mounted on the vehicle. The charging system includes a temperature detection section that detects a temperature of the charging port, a utilization start time acquisition section that acquires a utilization start time at which a user starts to utilize the vehicle, and a control section that, when charging of the battery is performed, performs control to flow a current larger than before to charge until just before the utilization start time, based on a detection result of the temperature detection section, when the temperature of the charging port is lower than a threshold temperature set in advance.

Description

Technical Field

[0001] This invention relates to charging systems. Background Technology

[0002] Japanese Patent Application Publication No. 2011-167003 discloses a technology that adds a heating mechanism to the charging connector of a charging device, and suppresses the freezing of the charging connector by supplying power to the heating mechanism when the charging connector connected to the charging port of a vehicle freezes at low temperatures and cannot be pulled out. Summary of the Invention

[0003] However, the technology disclosed in Japanese Patent Application Publication No. 2011-167003 requires an additional heating mechanism for heating the charging connector, which increases costs.

[0004] This invention provides a charging system that can suppress cost increases while preventing the charging connector from freezing and becoming unable to detach from the charging port.

[0005] The first aspect of the present invention is a charging system. The charging system is configured to charge a battery mounted in a vehicle by engaging a charging connector of a charging device with a charging port. The charging system includes a temperature detection unit, a usage start time acquisition unit, and a control unit. The temperature detection unit is configured to detect the temperature of the charging port. The usage start time acquisition unit is configured to acquire the usage start time when a user begins using the vehicle. The control unit is configured to, when charging the battery by engaging the charging port with the charging connector, based on the detection result of the temperature detection unit, execute control to flow a larger current than previously expected to charge the battery before the usage start time, if the temperature of the charging port is lower than a preset threshold temperature.

[0006] Based on the above configuration, the heat generated by the electrical resistance at the charging port and charging connector can be increased at low temperatures, preventing the mating part of the charging port and charging connector from freezing. This can suppress the cost increase caused by adding an additional heating mechanism to the charging connector, while also preventing the charging connector from freezing and becoming unable to detach from the charging port.

[0007] In the charging system, the control unit may increase the charging current as the start of charging approaches the start of utilization when the temperature of the charging port is lower than a preset threshold temperature.

[0008] Based on the above configuration, it is possible to prevent the charging port and charging connector from freezing before the start of use.

[0009] Furthermore, a second aspect of the present invention is a charging system. The charging system includes a control unit configured to engage a charging connector of a charging device with a vehicle's charging port to charge a battery mounted on the vehicle. After the battery is fully charged, the control unit initiates the disengagement of the charging connector from the charging port. The control unit is configured to, if it is impossible to disengage the charging connector from the charging port, perform alternating and repetitive control of discharging current from the charging port side to the charging connector side and charging current from the charging connector side to the charging port side.

[0010] Based on the above configuration, alternating and repeated charging and discharging can increase the heat generated by the electrical resistance at the charging port and charging connector, preventing the mating part of the charging port and charging connector from freezing. This can suppress the cost increase caused by adding an additional heating mechanism to the charging connector, while also preventing the charging connector from freezing and becoming unable to detach from the charging port.

[0011] In the charging system of the present invention, a portion of the charging connector may be made of a material with high thermal conductivity.

[0012] Based on the above configuration, it is possible to easily transfer the large amount of heat generated by the energizing resistance to the mating part of the charging port and the charging connector.

[0013] In the charging system involved in the present invention, an arm mechanism for holding the charging connector and automatically inserting or removing the charging connector relative to the charging port may also be provided in the charging device.

[0014] Based on the above configuration, the mating part between the charging port and the charging connector can be prevented from freezing even at low temperatures, allowing the charging connector to automatically detach from the charging port.

[0015] The charging system involved in the present invention has the following effects: it can increase the heat generated by the electrical resistance at the charging port and charging connector at low temperatures, avoid freezing of the mating part of the charging port and charging connector, and suppress the increase in cost caused by adding an additional heating mechanism to the charging connector while suppressing the situation where the charging connector freezes and cannot be detached from the charging port. Attached Figure Description

[0016] Hereinafter, with reference to the accompanying drawings, the features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described, in which the same reference numerals denote the same elements, and wherein:

[0017] Figure 1 This is a block diagram illustrating the configuration of the charging system according to the embodiment.

[0018] Figure 2 This is a flowchart illustrating an example of the charging control process implemented by the charging control unit.

[0019] Figure 3 This is a diagram showing an example of a low-temperature charging curve.

[0020] Figure 4 This is a graph showing an example of a room temperature charging curve.

[0021] Figure 5 This is another flowchart illustrating the charging control process implemented by the charging control unit.

[0022] Figure 6 This is an explanatory diagram about freezing to prevent charging and discharging. Detailed Implementation

[0023] Hereinafter, embodiments of the charging system according to the present invention will be described. However, the present invention is not limited to these embodiments.

[0024] Figure 1 This is a block diagram illustrating the configuration of the charging system 1 according to the embodiment. (As shown) Figure 1 As shown, the charging system 1 according to the embodiment is a system for charging the battery 21 mounted on the vehicle 2 by connecting the charging connector 33 of the charging device 3 installed on the outside of the vehicle 2, such as an electric vehicle, to the charging port 25 of the vehicle 2.

[0025] In this charging system 1, a battery 21, a charging control unit 22, a temperature detection unit 23, a utilization start time acquisition unit 24, and a charging port 25 are provided on the vehicle 2 side. However, depending on the model of the vehicle 2, there are cases where the temperature detection unit 23 and the utilization start time acquisition unit 24 are not provided.

[0026] Battery 21, for example, is composed of nickel-metal hydride batteries or lithium-ion batteries, and is a battery that stores high-voltage DC power used to drive vehicle 2.

[0027] The charging control unit 22 is composed of electronic circuitry, primarily consisting of a well-known microcomputer, including a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and input / output interfaces. The charging control unit 22 coordinates with the charging control unit 31 located on the charging device 3 side to control the charging process of charging the battery 21 using the charging device 3. Furthermore, the charging control unit 22 obtains information related to the SOC (State of Charge) of the battery 21 via an in-vehicle network such as CAN (Controller Area Network).

[0028] The temperature detection unit 23 consists of a temperature sensor mounted on the charging port 25. The temperature detection unit 23 detects the temperature T of the charging port 25 and outputs an electrical signal representing the detected temperature T of the charging port 25 to the charging control unit 22.

[0029] The start time acquisition unit 24 acquires the start time of the user's use of the vehicle 2. For example, the start time acquisition unit 24 acquires the start time of the user's use of the communication terminal, input device, etc., by communicating with the user's communication terminal, input device, etc.

[0030] The charging port 25 is constructed by providing a power-conducting terminal in a housing with a hole in which the charging connector 33 for the charging device 3 is inserted.

[0031] On the other hand, a charging control unit 31, a storage unit 32, and a charging connector 33 are provided on the charging device 3 side.

[0032] The charging control unit 31 is composed of electronic circuitry with a microcomputer as its main component, similar to that of the charging control unit 22. The charging control unit 31 coordinates with the charging control unit 22 on both sides of the vehicle to control the charging process of charging the battery 21 via the charging connector 33 and the charging port 25. Furthermore, the charging control unit 31 communicates with the charging control unit 22 to obtain various information, such as the temperature T of the charging port 25 detected by the temperature detection unit 23, the utilization start time obtained by the utilization start time acquisition unit 24, and information related to the state of charge (SOC) of the battery 21.

[0033] Furthermore, when the charging connector 33 is electrically connected to the charging port 25 by engaging with it, the charging control unit 31 obtains an engagement signal indicating an engaged state from the charging control unit 22 of the vehicle 2 via the charging port 25 and the charging connector 33, and determines that the charging connector 33 and the charging port 25 are engaged. At this time, the charging control unit 31 detects the start of engagement between the charging connector 33 and the charging port 25 at the initial point when the engagement signal is first obtained, and then detects that the engagement between the charging connector 33 and the charging port 25 is complete after the engagement signal has been continuously obtained for a certain period of time. On the other hand, if the charging control unit 31 no longer obtains the engagement signal, it determines that the charging connector 33 has disengaged from the charging port 25, and is in a state where the engagement between the charging connector 33 and the charging port 25 has been released (disengaged state). At this time, the charging control unit 31 detects the start of the disengagement of the charging connector 33 from the charging port 25 at, for example, the point at which the engagement signal is no longer acquired initially. Then, if the engagement signal is not continuously acquired for a certain period of time, it detects that the disengagement of the charging connector 33 from the charging port 25 is complete. Furthermore, the method for determining whether the charging connector 33 is engaged with the charging port 25, and the methods for detecting the start of engagement, the completion of engagement, the start of disengagement, and the completion of disengagement, are not particularly limited, and known techniques can be used.

[0034] The storage unit 32 stores information used when implementing charging control based on the charging control unit 31, such as normal temperature charging curves and low temperature charging curves.

[0035] The charging connector 33 consists of a power-contact terminal that is electrically connected to the power-contact terminal of the charging port 25 when inserted into the charging port 25 of the vehicle 2, and a retaining part that holds the power-contact terminal. The retaining part of the charging connector 33 is made of a highly thermally conductive material such as a resin material.

[0036] In the charging system 1 with this configuration, the charging control unit 31 on the charging device 3 side performs the charging control process as shown below, charging the battery 21 while preventing the charging connector 33 from freezing. The operation of the charging control unit 31 during the execution of the charging control process will be described below.

[0037] Figure 2This is a flowchart illustrating an example of the charging control process implemented by the charging control unit 31. First, the charging control unit 31 detects that the engagement between the charging connector 33 of the charging device 3 and the charging port 25 of the vehicle 2 has begun (step S1). Next, the charging control unit 31 detects that the engagement between the charging connector 33 of the charging device 3 and the charging port 25 of the vehicle 2 has been completed (step S2). Next, the charging control unit 31 begins charging (step S3). Next, the charging control unit 31 determines whether the temperature T of the charging port 25 detected by the temperature detection unit 23 is lower than a preset threshold temperature T0 (step S4). Furthermore, the threshold temperature T0 is set to a low temperature at which the charging connector 33 and the charging port 25 may freeze if the temperature is lower than the threshold temperature T0.

[0038] When the charging control unit 31 determines that the temperature T of the charging port 25 is less than the threshold temperature T0 ("Yes" in step S4), it obtains the start time of user's use of vehicle 2 from the use start time acquisition unit 24 (step S5). Furthermore, here, the start time of user's use of vehicle 2 is set to the departure time when the user departs from vehicle 2. Next, the charging control unit 31 performs charging using the low-temperature charging curve stored in the storage unit 32 (step S6).

[0039] Figure 3 This is a diagram showing an example of a low-temperature charging curve. In charging using the low-temperature charging curve, current flows to charge the battery 21 in a manner that ensures the battery 21 is fully charged before the acquired start time (using the start time). At this time, the charging control unit 31... Figure 3 As shown, from the start of charging, the current gradually increases as the start time approaches (utilizing the start time). Then, in the latter half of the charging process, just before the start time (utilizing the start time), a larger current than before is applied, resulting in the maximum current (high current) set in the low-temperature charging curve. After performing charging using the low-temperature charging curve, the charging control unit 31 proceeds to step S8.

[0040] On the other hand, in the processing of step S4, if the charging control unit 31 determines that the temperature T of the charging port 25 is above the threshold temperature T0 (in step S4, it is "No"), it performs charging using the normal temperature charging curve (step S7).

[0041] Figure 4 This is a diagram showing an example of a room temperature charging curve. In charging using a room temperature charging curve, current flows to charge the battery 21 so that it is fully charged as early as possible from the start of charging. At this time, the charging control unit 31... Figure 4As shown, from the start of charging, the maximum current (high current) set in the room temperature charging curve flows. As the battery 21 approaches full charge, the current gradually decreases, and in the latter half of charging, a low current flows to perform charging. Furthermore, after performing charging using the room temperature charging curve, the charging control unit 31 moves to step S8.

[0042] The charging control unit 31 performs charging using a low-temperature charging curve or a normal-temperature charging curve, and determines whether 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 the charging connector 33 of the charging device 3 has begun to disconnect from the charging port 25 of the vehicle 2 (step S9). Next, the charging control unit 31 detects that the disconnection of the charging connector 33 of the charging device 3 from the charging port 25 of the vehicle 2 has been completed (step S10). Then, the charging control unit 31 ends one example of charging control processing.

[0043] In the charging system 1 according to the embodiment, at the start of charging, the temperature T of the charging port 25 is detected by the temperature detection unit 23 mounted on the vehicle 2. The detected temperature T is compared with a threshold temperature T0 to determine whether the mating part of the charging port 25 and the charging connector 33 may freeze. If the temperature T is less than the threshold temperature T0, the user's vehicle 2 utilization start time, such as the departure time, is obtained, and then charging using a low-temperature charging curve is performed. In this low-temperature charging curve, a high current is applied just before the utilization start time (departure time). Therefore, compared with the case where a low current is applied in the latter half of the charging process, as in charging using a normal temperature charging curve, more heat is generated due to the resistance at the charging port 25 and the charging connector 33. In particular, in the charging system 1 according to the embodiment, a part (holding part) of the charging connector 33 is made of a material with high thermal conductivity, so it is easy to transfer the large amount of heat generated by the resistance to the mating part of the charging port 25 and the charging connector 33.

[0044] Therefore, in the charging system 1 according to the embodiment, it is possible to avoid adding a heating mechanism to the charging connector 33, thereby preventing an increase in heat generation caused by the electrical resistance at the charging port 25 and the charging connector 33. Even at low temperatures, the mating portion of the charging port 25 and the charging connector 33 is heated before the start of use (departure time) to prevent freezing. Thus, in the charging system 1 according to the embodiment, it is possible to suppress cost increases while preventing freezing and the charging connector 33 from detaching from the charging port 25.

[0045] Figure 5This is a flowchart illustrating another example of the charging control process implemented by the charging control unit 31. First, the charging control unit 31 detects that the engagement of the charging connector 33 of the charging device 3 with the charging port 25 of the vehicle 2 has begun (step S11). Next, the charging control unit 31 detects that the engagement of the charging connector 33 of the charging device 3 with the charging port 25 of the vehicle 2 has been completed (step S12). Next, the charging control unit 31 begins charging (step S13). Based on information related to 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 disengagement of the charging connector 33 of the charging device 3 from the charging port 25 of the vehicle 2 has begun (step S15). Next, the charging control unit 31 determines whether the disengagement of the charging connector 33 of the charging device 3 from the charging port 25 of the vehicle 2 has been completed (step S16). If the charging control unit 31 determines that the disengagement of the charging connector 33 from the charging port 25 has been completed ("Yes" in step S16), the series of charging control processes ends. On the other hand, if the charging control unit 31 determines that the disconnection of the charging connector 33 from the charging port 25 is not completed ("No" in step S16), it considers the charging connector 33 and the charging port 25 to be frozen, and performs freezing to avoid charging and discharging (step S17).

[0046] This freezing to prevent charging and discharging is to prevent the charging connector 33 from completely disengaging from the charging port 25 after the charging control unit 31 determines that the disengagement is incomplete (disengagement NG). Figure 6 As shown, the discharge process, in a manner that balances the power supply and demand, alternately and repeatedly performs discharge, in which current flows from the charging port 25 side to the charging connector 33 side (from the battery 21 side of the vehicle 2 to the charging device 3 side), and charging process, in which current flows from the charging connector 33 side to the charging port 25 side (from the charging device 3 side to the battery 21 side of the vehicle 2). This maintains the SOC of the battery 21 within a predetermined range while preventing the mating portion of the charging port 25 and the charging connector 33 from freezing due to the heat generated by the resistance at the charging port 25 and the charging connector 33.

[0047] After freezing to prevent charging and discharging for a certain period of time, the process moves to step S16 and repeats the freezing to prevent charging and discharging process until it is determined that the charging connector 33 has been completely disconnected from the charging port 25. Then, if the charging control unit 31 determines that the charging connector 33 has been completely disconnected from the charging port 25 ("Yes" in step S16), it ends the series of charging and discharging control processes.

[0048] In the charging system 1 according to the embodiment, if the charging connector 33 cannot detach from the charging port 25 when charging is finished, it is determined that the charging connector 33 and the charging port 25 are frozen. Charging and discharging are then performed in a way that balances the power supply, and power is supplied between the charging port 25 and the charging connector 33. Therefore, in the charging system 1 according to the embodiment, without adding an additional heating mechanism to the charging connector 33, even at low temperatures, the heat generated by the resistance at the charging port 25 and the charging connector 33 increases, preventing the mating portion of the charging port 25 and the charging connector 33 from freezing and allowing the charging connector 33 to detach from the charging port 25.

[0049] Furthermore, the charging system 1 described in the embodiment is not limited to manual operation by the user to insert and remove the charging connector 33 of the charging device 3 relative to the charging port 25 of the vehicle 2. For example, an automatic charging device can be used, in which an arm mechanism is provided on the charging device 3 to hold the charging connector 33 and automatically insert and remove the charging connector 33 relative to the charging port 25. As a result, when the battery 21 of the vehicle 2 is charged by the automatic charging device, the heat generated by the resistance at the charging port 25 and the charging connector 33 can be increased. At low temperatures, the mating part of the charging port 25 and the charging connector 33 is prevented from freezing, and the charging connector 33 is automatically detached from the charging port 25.

[0050] Furthermore, when using an automatic charging device, determining whether the charging connector 33 is engaged with the charging port 25, and detecting the start of engagement, completion of engagement, start of disengagement, and completion of disengagement, can be performed, in addition to the methods described above, for example, based on the operating state of the arm mechanism. For example, the time when the arm mechanism holds the charging connector 33 and begins to insert the charging connector 33 into the charging port 25 can be used as the start time of engagement between the charging connector 33 and the charging port 25.

Claims

1. A charging system configured to charge a battery mounted in a vehicle by engaging a charging connector of a charging device with a charging port of the vehicle, characterized in that, have: The temperature detection unit is configured to detect the temperature of the charging port; The start time acquisition unit is configured to acquire the start time of user's commencement of use of the vehicle; and The control unit is configured to, when charging the battery by engaging the charging port with the charging connector, based on the detection result of the temperature detection unit, execute control to flow a larger current than before to charge the battery just before the start of the usage time, if the temperature of the charging port is lower than a preset threshold temperature. The control unit is further configured to engage the charging port with the charging connector to charge the battery, and after the battery is fully charged, to begin disengaging the charging connector from the charging port. If it is determined that the disengagement of the charging connector from the charging port is incomplete, control is executed to alternately and repeatedly discharge current from the charging port side to the charging connector side and charge current from the charging connector side to the charging port side in a manner that balances the power supply and demand, until it is determined that the disengagement of the charging connector from the charging port is complete.

2. The charging system according to claim 1, characterized in that, When the temperature of the charging port is lower than a preset threshold temperature, the control unit increases the charging current as the start of use approaches.

3. The charging system according to claim 1 or 2, characterized in that, A portion of the charging connector is made of a material with high thermal conductivity.

4. The charging system according to claim 1 or 2, characterized in that, The charging device is provided with an arm mechanism that holds the charging connector and automatically inserts or removes the charging connector relative to the charging port.

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