Charge control device and charge control method

Abstract

To make sure that charging time is not long.SOLUTION: An ECU controls charging of a battery. The ECU includes a CPU and a communication unit for communicating with a charger. The CPU identifies a limit value Win of charging power after a predetermined period (step S113), determines whether power corresponding to a current charging command value to the charger exceeds the limit value Win (step S114), and if it determines that the power corresponding to the charging command value exceeds the limit value Win, limits the charging command value so that the power corresponding to the charging command value does not exceed the limit value Win before the predetermined period has elapsed (step S115), and controls the communication unit to transmit the limited charging command value to the charger (step S117). This makes it possible to limit the charging command value only when necessary, and not to limit the charging command value except when necessary.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a charge control device and a charge control method, and more particularly to a charge control device that controls charging of a power storage device and a charge control method using the charge control device. [Background technology]

[0002] Conventionally, in order to prevent the charging power limit value from being exceeded when charging a power storage device, a margin has been provided for a predicted value of the charging power (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-182262 A Summary of the Invention [Problem to be solved by the invention]

[0004] There is a possibility that various chargers may be used when charging, and there was an issue that adding a margin to accommodate various chargers would result in longer charging times.

[0005] This disclosure has been made to solve the above-mentioned problems, and its purpose is to provide a charge control device and a charge control method that can prevent the charging time from being long. [Means for solving the problem]

[0006] A charging control device according to the present disclosure controls charging of a power storage device. The charging control device includes a processor and a communication unit for communicating with a charger. The processor identifies a limit value for charging power after a predetermined period of time, determines whether the power corresponding to a current charging command value to the charger will exceed the limit value, and if it determines that the power corresponding to the charging command value will exceed the limit value, limits the charging command value so that the power corresponding to the charging command value does not exceed the limit value before the predetermined period has elapsed, and controls the communication unit to transmit the limited charging command value to the charger.

[0007] According to this configuration, when it is determined that the power corresponding to the current charging command value to the charger will exceed the limit value of the charging power after a predetermined period of time, a charging command value limited so that the power corresponding to the charging command value does not exceed the limit value until the predetermined period of time has elapsed is transmitted to the charger. This makes it possible to limit the charging command value only when necessary and not limit the charging command value when not necessary. As a result, it is possible to provide a charging control device that can prevent the charging time from becoming long.

[0008] The processor may limit the charge command value by lowering it in a predetermined manner. With this configuration, the charge command value can be appropriately limited when necessary.

[0009] When the processor determines that the power corresponding to the charge command value does not exceed the limit value, the processor may maintain the charge command value and control the communication unit to transmit the maintained charge command value to the charger. With this configuration, it is possible to avoid limiting the charge command value unless necessary.

[0010] The processor may calculate the charge amount of the power storage device that increases over a predetermined period of time, and specify the limit value using the calculated charge amount. With this configuration, the limit value of the charge power after the predetermined period of time can be appropriately specified.

[0011] According to another aspect of the disclosure, a charging control method is a charging control method by a charging control device that controls charging of a power storage device. The charging control device includes a processor and a communication unit for communicating with a charger. The charging control method includes a step of the processor specifying a limit value of charging power after a predetermined period of time, a step of determining whether power corresponding to a current charging command value to the charger exceeds the limit value, and a step of limiting the charging command value when it is determined that the power corresponding to the charging command value exceeds the limit value so that the power corresponding to the charging command value does not exceed the limit value until the predetermined period has elapsed, and a step of controlling the communication unit to transmit the limited charging command value to the charger.

[0012] According to this configuration, it is possible to provide a charging control method that can prevent the charging time from becoming long. Effect of the Invention

[0013] According to this disclosure, it is possible to provide a charge control device and a charge control method that can prevent a charging time from becoming long. [Brief description of the drawings]

[0014] [Figure 1] 1 is a diagram illustrating an overall configuration of a charging system according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a diagram showing the configuration of a charging system in more detail. [Diagram 3] 4 is a flowchart showing a flow of a charging control process in this embodiment. [Figure 4] 10 is a flowchart showing a flow of a charge control process when a margin is provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and their description will not be repeated.

[0016] <Charging system configuration> 1 is a diagram illustrating a schematic overall configuration of a charging system 9 according to this embodiment. With reference to FIG 1, the charging system 9 includes a vehicle 1 of a user, a charger 3, and a charging cable 4 extending from the charger 3.

[0017] Vehicle 1 is, for example, an electric vehicle equipped with a battery 11 (see FIG. 2 described later). Vehicle 1 is configured to enable "external charging" in which battery 11 is charged with power supplied from charger 3 in a state in which vehicle 1 and charger 3 are electrically connected by a charging cable 4. Note that vehicle 1 may be a plug-in hybrid vehicle or a fuel cell vehicle as long as it is configured to enable external charging.

[0018] The charger 3 is installed, for example, at a public charging stand (also called a charging spot or a charging station). The charger 3 converts AC power (for example, a three-phase 200V power supply) supplied from a commercial power source into DC power and supplies the DC power to the vehicle 1.

[0019] In this embodiment, the charger 3 is a charger that supports quick charging. Furthermore, for the charger 3 in this embodiment, a nominal minimum power corresponding to a nominal minimum current that can be output is determined in advance, and this nominal minimum power is stored. The charger 3 transmits this minimum power to the vehicle 1 when charging of the battery 11 of the vehicle 1 starts.

[0020] Fig. 2 is a diagram showing in more detail the configuration of charging system 9. With reference to Fig. 1 and Fig. 2, vehicle 1 includes battery 11, a monitoring unit 111, a system main relay (SMR) 121, a power control unit (PCU) 122, a motor generator (MG) 123, a power transmission gear 124, driving wheels 125, and an ECU (Electronic Control Unit) 10.

[0021] The battery 11 is a rechargeable power storage device, and includes a secondary battery such as a lithium ion secondary battery or a nickel-metal hydride battery. The battery 11 supplies the PCU 122 with electric power for generating a driving force for the vehicle 1 to travel. The battery 11 is charged with electric power generated by regenerative braking of the motor generator 123, or with electric power supplied from the charger 3. Instead of the battery 11, a capacitor such as an electric double layer capacitor may be used.

[0022] The monitoring unit 111 monitors the state of the battery 11. Although none of these are shown, the monitoring unit 111 includes a voltage sensor, a current sensor, and a temperature sensor. The voltage sensor detects the voltage Vb of the battery 11. The current sensor detects the current Ib input to and output from the battery 11. The temperature sensor detects the temperature of the battery 11. Each sensor outputs the detection result to the ECU 10. The ECU 10 can calculate the SOC (State Of Charge) of the battery 11 based on the detection results of each sensor.

[0023] The SMR 121 is electrically connected between the battery 11 and the PCU 122. The closing / opening of the SMR 121 is controlled in response to a command from the ECU 10.

[0024] The PCU 122 is a power conversion device that performs power conversion between the battery 11 and the motor generator 123 in accordance with a command from the ECU 10. The PCU 122 includes an inverter that receives power from the battery 11 and drives the motor generator 123, and a converter that adjusts the level of the DC voltage supplied to the inverter (neither of which is shown), and the like.

[0025] The motor generator 123 is an AC motor. The motor generator 123 is driven by an inverter included in the PCU 122 to rotate a drive shaft. Torque output by the motor generator 123 is transmitted to drive wheels 125 via a power transmission gear 124, thereby causing the vehicle 1 to run. Furthermore, when braking the vehicle, the motor generator 123 receives the rotational force of the drive wheels 125 to generate electricity. The electric power generated by the motor generator 123 is charged into the battery 11 via the PCU 122.

[0026] Vehicle 1 further includes a charging relay 131, power lines PL, GL, and an inlet 135 as components for rapid charging.

[0027] The charger 3 includes a control device 30 and a power supply unit 31. The charging cable 4 includes a power line 42, a communication line 43, and a connector 41.

[0028] During rapid charging of the battery 11, the connector 41 of the charging cable 4 is connected to the inlet 135. Then, power from the charger 3 is supplied to the vehicle 1 through the power line 42 in the charging cable 4, and transmitted to the charging relay 131 through the power lines PL and GL.

[0029] The charging relay 131 and the SMR 121 are electrically connected between the battery 11 and the inlet 135. When the charging relay 131 is closed and the SMR 121 is closed, power transmission between the inlet 135 and the battery 11 is enabled.

[0030] In addition, when the vehicle 1 and the charger 3 are connected by the charging cable 4, the ECU 10 is configured to be able to communicate bidirectionally with the control device 30 of the charger 3 via a communication line 43 in the charging cable 4 and the in-vehicle network 16.

[0031] The ECU 10 includes a CPU (Central Processing Unit) 101, a memory 102, a communication unit 103, an input / output port (not shown) for inputting and outputting various signals, etc. The ECU 10 controls each device (SMR 121, PCU 122, charging relay 131, etc.) in the vehicle 1 so that the vehicle 1 is in a desired state.

[0032] If the battery 11 is charged with high power, the battery 11 may break down or its lifespan may be shortened. For this reason, a limit value Win of the charging power is determined in advance for each battery 11 according to the SOC, temperature, voltage, and current of the battery 11.

[0033] In order not to exceed the limit value Win of the charging power when charging the battery 11 of the vehicle 1 described above, it is considered to provide a margin for the predicted value of the charging power. FIG. 4 is a flowchart showing the flow of the charging control process when a margin is provided. Specifically, with reference to FIG. 4, it is considered to be done as follows. The CPU 101 of the ECU 10 judges whether or not charging is in progress (step S911). If it is judged that charging is in progress (YES in step S911), the current limit value Win is specified from the SOC (State Of Charge), temperature, and voltage of the battery 11 (step S913), a margin is added to the limit value Win (step S915), a charging command value corresponding to the Win with the margin added is calculated (step S916), and the communication unit 103 of the ECU 10 is controlled to transmit the calculated charging command value to the charger 3 (step S917).

[0034] During charging, various chargers 3 may be used. If a margin is provided in step S915 to accommodate various chargers 3, the charging command value will be lowered even when it is not necessary, which causes a problem of longer charging time.

[0035] Therefore, the CPU 101 of the ECU 10 identifies a limit value Win of the charging power after a predetermined period of time, determines whether the power corresponding to the current charging command value to the charger 3 will exceed the limit value Win, and if it determines that the power corresponding to the charging command value will exceed the limit value Win, limits the charging command value so that the power corresponding to the charging command value does not exceed the limit value Win before the predetermined period has elapsed, and controls the communication unit 103 of the ECU 10 to transmit the limited charging command value to the charger 3.

[0036] As a result, when it is determined that the power corresponding to the current charging command value to the charger 3 will exceed the limit value Win of the charging power after a predetermined period of time, a charging command value limited so that the power corresponding to the charging command value does not exceed the limit value Win until the predetermined period has elapsed is transmitted to the charger 3. This makes it possible to limit the charging command value only when necessary, and not to limit the charging command value unless necessary. As a result, it is possible to prevent the charging time from becoming long.

[0037] 3 is a flowchart showing a flow of the charge control process in this embodiment. Referring to FIG 3, the charge control process is called from a higher-level process by the CPU 101 of the ECU 10 at predetermined intervals and executed.

[0038] The CPU 101 of the ECU 10 determines whether charging is in progress (step S111). If it is determined that charging is not in progress (NO in step S111), the CPU 101 returns the process to be executed to the upper process that called this charging control process.

[0039] On the other hand, if it is determined that charging is in progress (YES in step S111), CPU 101 calculates ΔSOC that increases in a predetermined period (for example, T seconds) (step S112). ΔSOC can be calculated by multiplying the maximum current that charger 3 can output, or, when charging power is limited, the limited current by T, and converting the result into SOC.

[0040] The current value of the actual charging command value is not necessarily equal to the maximum current or the limited current. For example, the current value of the actual charging command value differs depending on the charging method. In CC (Constant Current) charging, charging is performed at a constant current value until the termination conditions (normal voltage, charging power amount) are reached. In CCCV (Constant Current, Constant Voltage) charging, charging is performed by CC charging until a predetermined voltage is reached, and when the predetermined voltage is reached, the charging current is reduced to maintain the predetermined voltage. The current value of the actual charging command value differs depending on the charging method and charging conditions. A current value according to the charging method is calculated, and the power corresponding to the calculated current value is compared with the limit value Win of the current charging power. If the limit value Win is not exceeded, the calculated current value is set as the charging command value, and if it is exceeded, a current value limited so as not to exceed the limit value Win is set as the charging command value.

[0041] Next, CPU 101 specifies a limit value Win of charging power after a predetermined period (e.g., T seconds) taking into consideration ΔSOC calculated in step S112 (step S113). For example, the charge amount (e.g., SOC) of battery 11 that increases during the predetermined period is calculated, and the charge amount is used to specify limit value Win of charging power. CPU 101 then determines whether or not the power corresponding to the current charging command value exceeds limit value Win of charging power after a predetermined period (e.g., T seconds) (step S114).

[0042] When it is determined that the power corresponding to the current charging command value exceeds the limit value Win of the charging power after the predetermined period (YES in step S114), CPU 101 limits the charging command value so that the charging command value does not exceed the limit value Win of the charging power within the predetermined period (for example, T seconds) (step S115). The charging command value is limited by lowering it in a predetermined manner. The predetermined manner may be, for example, a manner of lowering the charging command value by a predetermined rate, a manner of lowering the charging command value by a predetermined value, a manner of lowering the charging command value proportionally, or a manner of lowering the charging command value exponentially.

[0043] On the other hand, when it is determined that the power corresponding to the current charging command value does not exceed the limit value Win of the charging power after the predetermined period (NO in step S114), the CPU 101 leaves the charging command value as it is (step S116).

[0044] Then, CPU 101 transmits the charge command value determined in step S115 or step S116 to charger 3 (step S117). After that, CPU 101 returns the process to be executed to the higher-level process that called this charge control process.

[0045] When the control device 30 of the charger 3 receives a charging command value, it controls the power supply unit 31 to supply power of the current value of the charging command value to the vehicle 1 if the current value of the charging command value does not exceed the maximum current of the charger 3, and if it does exceed the maximum current, it controls the power supply unit 31 to supply power corresponding to the maximum current to the vehicle 1.

[0046] [Variations] (1) In the above-described embodiment, the charge command value to the charger 3 is a current value. However, this is not limited thereto, and the charge command value to the charger 3 may be a power value.

[0047] (2) The above disclosure can be regarded as disclosure of a charge control device such as ECU 10 that controls charging of battery 11, or as disclosure of a charge control method by the charge control device or a charge control program that executes the processing shown in FIG. 3.

[0048] [summary] (1) As shown in Fig. 1 and Fig. 2, the ECU 10 controls charging of the battery 11. As shown in Fig. 2, the ECU 10 includes a CPU 101 and a communication unit 103 for communicating with the charger 3. As shown in Fig. 3, the CPU 101 identifies a limit value Win of charging power after a predetermined period (for example, T seconds) (for example, step S113), determines whether the power corresponding to the current charging command value to the charger 3 exceeds the limit value Win (for example, step S114), and when it is determined that the power corresponding to the charging command value exceeds the limit value Win, limits the charging command value so that the power corresponding to the charging command value does not exceed the limit value Win before the predetermined period has elapsed (for example, step S115), and controls the communication unit 103 to transmit the limited charging command value to the charger 3 (for example, step S117).

[0049] As a result, when it is determined that the power corresponding to the current charging command value to the charger 3 will exceed the limit value Win of the charging power after a predetermined period of time, a charging command value limited so that the power corresponding to the charging command value does not exceed the limit value Win until the predetermined period has elapsed is transmitted to the charger 3. This makes it possible to limit the charging command value only when necessary, and not to limit the charging command value unless necessary. As a result, it is possible to prevent the charging time from becoming long.

[0050] (2) As shown in Fig. 3, the CPU 101 may limit the charge command value by lowering it in a predetermined manner (for example, step S115). This makes it possible to appropriately limit the charge command value when necessary.

[0051] (3) As shown in Fig. 3, when the CPU 101 determines that the power corresponding to the charging command value does not exceed the limit value Win, the CPU 101 may maintain the charging command value (for example, step S116) and control the communication unit 103 to transmit the maintained charging command value to the charger 3 (for example, step S117). This makes it possible to avoid limiting the charging command value unless necessary.

[0052] 3, the CPU 101 may calculate the charge amount (e.g., SOC) of the battery 11 that increases over a predetermined period (e.g., step S112) and specify the limit value Win using the calculated charge amount (e.g., step S113). This allows the limit value Win of the charging power after the predetermined period to be appropriately specified.

[0053] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the disclosure is defined by the claims, not by the description of the embodiments described above, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0054] 1 vehicle, 3 charger, 4 charging cable, 9 charging system, 10 ECU, 11 battery, 16 on-board network, 30 control device, 31 power supply unit, 41 connector, 42,GL,PL power lines, 43 communication line, 101 CPU, 102 memory, 103 communication unit, 111 monitoring unit, 121 SMR, 122 PCU, 123 motor generator, 124 power transmission gear, 125 drive wheel, 131 charging relay, 135 inlet.

Claims

1. A charge control device that controls charging of a power storage device, A processor; A communication unit for communicating with the charger, The processor, Identifying a limit value of charging power after a predetermined period of time; determining whether the power corresponding to a current charging command value to the charger exceeds the limit value; when it is determined that the power corresponding to the charging command value will exceed the limit value, limiting the charging command value so that the power corresponding to the charging command value does not exceed the limit value until the predetermined period has elapsed; The charge control device controls the communication unit to transmit the limited charge command value to the charger.

2. The charge control device according to claim 1 , wherein the processor limits the charge command value by lowering it in a predetermined manner.

3. The processor, When it is determined that the power corresponding to the charging command value does not exceed the limit value, the charging command value is maintained; The charge control device according to claim 1 , further comprising: a control unit configured to control the communication unit so as to transmit the maintained charge command value to the charger.

4. The processor, Calculating an increase in a charge amount of the power storage device during the predetermined period; The charge control device according to claim 1 , wherein the limit value is determined by using the calculated charged amount.

5. A charge control method for controlling charging of a power storage device, comprising: The charging control device includes: A processor; A communication unit for communicating with the charger, The charging control method includes: determining a limit value of charging power after a predetermined period of time; determining whether a power corresponding to a current charging command value to the charger exceeds the limit value; When it is determined that the power corresponding to the charging command value will exceed the limit value, limiting the charging command value so that the power corresponding to the charging command value does not exceed the limit value until the predetermined period has elapsed; and controlling the communication unit to transmit the limited charging command value to the charger.

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