Charging device

Abstract

To provide a charging device capable of presenting charging time to a user.SOLUTION: A charging device disclosed in this specification estimates and displays a charging time from the difference between the current capacity and target charging capacity of a battery and the current supplied to the battery. A user can know the charging time by looking at the display of the charging device. The charging device may estimate the charging time from the pattern of the current (current supplied to the battery) from the current capacity to the target charging capacity. This makes it possible to estimate the charging time more accurately. Furthermore, when the current supplied to the battery exceeds a predetermined normal charging current value, the charging device may display that the charging time is to be shorter than normal. The charging device may display the planned charging end time, which is the current time plus the charging time. The planned charging end time is equivalent to the charging time.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a charging device that charges a battery. [Background technology]

[0002] The charging efficiency of a battery decreases when the temperature is low. In order to use the battery effectively, technologies for heating the battery before charging are disclosed in Patent Documents 1 and 2. Patent Document 1 proposes using a seat heater to warm the battery. Patent Document 2 proposes heating the battery by varying the voltage applied to the battery at a frequency lower than normal.

[0003] Technologies for raising the temperature of a battery are also disclosed in Patent Documents 3 and 4. Patent Documents 3 and 4 disclose technologies for raising the temperature of a battery in an electric vehicle equipped with a motor and a battery. Patent Documents 3 and 4 propose raising the temperature of the battery by transferring power back and forth between the battery and a coil of a motor via an inverter and charging and discharging the battery.

[0004] On the other hand, in recent years, in order to shorten the charging time, a current larger than normal is sometimes supplied to the battery (so-called quick charging). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2011-238428 A [Patent Document 2] JP 2002-369402 A [Patent Document 3] JP 2023-95217 A [Patent Document 4] Patent Publication No. 2023-38755 Summary of the Invention [Problem to be solved by the invention]

[0006] The charging time varies depending on the battery condition. Also, the charging time varies depending on the amount of current supplied to the battery. It is inconvenient if you do not know the charging time. [Means for solving the problem]

[0007] The charging device disclosed in this specification estimates and displays the planned charging time until the battery reaches the target charging capacity from the difference between the current capacity of the battery and the target charging capacity and the current supplied to the battery. The charging device disclosed in this specification can present the planned charging time to the user.

[0008] The charging device may identify a pattern of the current (current supplied to the battery) from the current capacity to the target charging capacity, and estimate the planned charging time based on the identified pattern. The planned charging time can be estimated more accurately. Furthermore, the charging device may display a message indicating that the charging time will be shorter than normal when the current supplied to the battery is greater than a predetermined normal charging current value.

[0009] The charging device may display a planned charging end time obtained by adding the planned charging time to the current time. The planned charging end time is equivalent to the planned charging time. Details and further improvements of the technology disclosed in this specification will be described in the "Description of Embodiments" below. [Brief description of the drawings]

[0010] [Figure 1] 1 is a block diagram of an electric vehicle equipped with a charging device according to an embodiment and a charging station. [Diagram 2] 4 is a flowchart of charging control performed by a controller of the charging device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A charging device 10 according to an embodiment will be described with reference to the drawings. The charging device 10 is mounted on an electric vehicle 100. Fig. 1 is a block diagram of the electric vehicle 100 including the charging device 10 and a charging stand 200. In Fig. 1, dotted arrows indicate signal lines.

[0012] The electric vehicle 100 is equipped with a motor and inverter (not shown), a battery 101, and a voltage converter 102. The DC power of the battery 101 is converted to AC by the inverter and supplied to the motor. The motor drives the wheels. When the charge level of the battery 101 becomes low, the user goes to a charging station 200 and charges the battery 101 with a power source 201. The power source 201 is equipped with a controller 202 and a display device 203.

[0013] A user connects the charging plug 204 of the power source 201 to the charging port 103 of the electric vehicle 100. When the controller 11 of the charging device 10 detects the connection of the charging plug 204, it communicates with the controller 202 of the power source 201 and starts charging. If the voltage of the power supplied by the power source 201 differs from the voltage of the battery 101, the voltage converter 102 adjusts the voltage. The charging device 10 includes a display device 12 in addition to the controller 11. The controller 11 causes the display device 12 to display the charging status. The controller 11 also communicates the charging status to the controller 202 of the power source 201. The controller 202 causes the display device 203 to display the charging status.

[0014] The displayed charging state includes the charging time until the battery 101 reaches the target charging capacity. The user can know the time until the target charging capacity is reached (i.e., the scheduled end time of charging). In addition, when the current supplied to the battery 101 is larger than the normal charging current value, the controller 11 displays the text "Quick charging" on the display device 12. The controller 202 also displays the text "Quick charging" on the display device 203. "Quick charging" means that a large current is supplied to the battery 101. When "quick charging" is performed, the charging time of the battery 101 is shortened. The target charging capacity is specified by the user prior to charging. The target charging capacity is typically the maximum charging capacity of the battery 101, that is, the fully charged capacity. The charging capacity of the battery 101 is often expressed as a percentage when the fully charged capacity is set to 100%.

[0015] Fig. 2 shows a flowchart of the charging process executed by the controller 11. The charging process will be described with reference to Fig. 2. When the controller 11 detects that the charging plug 204 is connected to the charging port 103, it starts the process of Fig. 2.

[0016] The controller 11 acquires the current capacity of the battery (current capacity) and the temperature of the battery 101 (step S2). Note that the battery 101 is equipped with a temperature sensor.

[0017] Next, the controller 11 communicates with the controller 202 of the power supply 201 and acquires information about the power supply 201 (step S3). The information acquired by the controller 11 includes the output voltage and maximum output current value of the power supply 201.

[0018] Next, the controller 11 identifies a pattern of a current to be supplied to the battery 101 (current pattern) (step S4). For convenience of explanation, the current supplied to the battery 101 will be referred to as a supply current hereinafter.

[0019] For example, if the temperature of the battery 101 is lower than a predetermined low temperature threshold, the controller 11 varies the supply current at a predetermined frequency so that the battery 101 warms up for a predetermined time from the start of charging. Supplying an oscillating current to the battery 101 increases the loss inside the battery 101, causing the battery 101 to generate heat. As a result, the battery 101 warms up. After the predetermined time has elapsed, the controller 11 stops varying the supply current.

[0020] The controller 11 controls the voltage converter 102. When the output voltage of the power source 201 is different from the voltage of the battery 101, the voltage converter 102 converts the output voltage of the power source 201 into a voltage suitable for charging the battery 101. In addition, the controller 11 oscillates the output voltage of the voltage converter 102, thereby fluctuating the supply current.

[0021] If the temperature of the battery 101 exceeds the low temperature threshold, there is no need to vary the supply current. In this case, the controller 11 starts charging without varying the supply current.

[0022] The controller 11 determines the magnitude of the supply current from information on the power source 201. The controller 11 limits the supply current while the supply current is being varied to raise the temperature of the battery 101. The controller 11 determines whether or not to vary the supply current based on the temperature of the battery 101, and specifies the supply current pattern (current pattern) until the target charge capacity is reached based on whether or not the variation is necessary and the magnitude of the supply current after the variation.

[0023] The controller 11 calculates the time (planned charging time) until the battery 101 reaches the target charging capacity from the difference between the current capacity and the target charging capacity and the current pattern (step S5). The time until the integrated value of the current pattern reaches "target charging capacity - current capacity" becomes the planned charging time.

[0024] Next, the controller 11 causes its own display device 12 to display the planned charging time (step S6). At the same time, the controller 11 also notifies the controller 202 of the power source 201 of the planned charging time. The controller 202 causes the display device 203 to display the planned charging time. The planned charging time to be displayed may be the planned charging end time. The planned charging end time is obtained by adding the planned charging time to the current time. In other words, the planned charging end time is equivalent to the planned charging time.

[0025] Next, the controller 11 commands the controller 202 of the power source 201 to start charging (step S7). The controller 11 also controls the voltage converter 102 so that the supply current changes according to the current pattern. As described above, when changing the supply current, the controller 11 changes the output voltage of the voltage converter 102.

[0026] The controller 11 periodically recalculates the planned charging time and updates the display until the battery 101 reaches the target charging capacity (steps S8: NO, S9). In step S9, the controller 11 executes the following process in addition to recalculating the planned charging time. If the supplied current is greater than a predetermined normal charging current value, the controller 11 causes the display device 12 to display the words "rapid charging in progress." The controller 11 also causes the display device 203 of the power source 201 to display the words "rapid charging in progress." "Rapid charging in progress" informs the user that the supplied current is greater than normal and that the charging time will be shorter than normal.

[0027] When the battery 101 reaches the target charge capacity, the controller 11 commands the controller 202 of the power source 201 to stop charging, and ends the process (step S8: YES, S10).

[0028] The charging device 10 of the embodiment displays the planned charging time (or the planned charging end time). By looking at the display device 12 (203), the user can know the time required until charging is completed (or the time when charging is scheduled to end).

[0029] Points to note regarding the technology described in the embodiment are described below. When the temperature of the battery 101 is low, the controller 11 limits the maximum value of the supply current to a value lower than that during normal charging, and varies the supply current. While varying the supply current, the controller 11 may cause the display device 12 (203) to display the message "Battery heating up."

[0030] The charging device 10 of the embodiment is mounted on an electric vehicle 100. The charging device may be installed in a charging station 200. A voltage converter 102 that converts the voltage of a power source 201 into a voltage suitable for charging the battery 101 may also be installed in the charging station 200.

[0031] When a charging device is installed at a charging station, various types of batteries may be connected to the power supply of the charging station. That is, a battery with unknown characteristics is connected to the charging device. In this case, the charging device may investigate a current fluctuation frequency suitable for heating the battery before heating the battery. The investigation process of the current fluctuation frequency will be outlined. The controller of the charging device varies the supply current at a predetermined frequency while limiting the supply current to a predetermined small current value. The controller measures the temperature rise of the battery after a certain period of time has elapsed since the supply of the varying current. This process is performed while changing the frequency. The controller identifies the frequency at which the temperature rise was the largest. This frequency is the frequency at which the battery can be efficiently heated. The controller supplies the battery with a current that varies at the identified frequency until the temperature of the battery exceeds the minimum temperature suitable for charging.

[0032] Although specific examples of the present invention have been described above in detail, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives is itself technically useful. [Explanation of symbols]

[0033] 10: Charging device 11, 202: Controller 12, 203: Display device 100: Electric vehicle 101: Battery 102: Voltage converter 103: Charging port 200: Charging stand 201: Power source 204: Charging plug

Claims

1. A charging device that estimates and displays a planned charging time until a battery reaches a target charging capacity based on the difference between the current capacity of the battery and the target charging capacity and the current supplied to the battery.

2. The charging device according to claim 1 , further comprising: a current pattern for a period from the current capacity to the target charging capacity; and an estimated charging time based on the identified current pattern.

3. 3. The charging device according to claim 1, further comprising a display indicating that the charging time will be shorter than normal when the current is greater than a predetermined normal charging current value.

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