Charging control system, charging control method, and program

Abstract

To provide a charge control system or the like which appropriately calculates cell parameters of a battery while suppressing elongation of the time required for charging the battery.SOLUTION: A charge control system 100 comprises charge control means which calculates predetermined cell parameters of a battery 21 based on a state amount of the battery 21 in charging the battery 21 in an intermittent manner. The charge control means performs the next intermittent charge in different timing from the present intermittent charge, and this timing is set based on a charging rate, a voltage or internal resistance of the battery 21 in temporarily stopping the charge during the intermittent charge of the battery 21.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a charging control system and the like.

Background Art

[0002] In order to reduce carbon dioxide emissions, electrification using batteries is being promoted not only in automobiles but also in all moving bodies on water, land, and air (ships, railway vehicles on non-electrified lines, aircraft, flying objects, etc.), regardless of whether they are manned or unmanned. As a charging control system for controlling the charging of such batteries, for example, the technique described in Patent Document 1 is known.

[0003] That is, Patent Document 1 describes that "when the terminal voltage of the secondary battery during charging reaches a predetermined voltage or when the charging capacity of the secondary battery reaches a predetermined capacity, the charging of the secondary battery is temporarily stopped, and after detecting the open terminal voltage of the secondary battery, the charging of the secondary battery is restarted and charged until full charge."

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the technique described in Patent Document 1, it is premised that the characteristics of the secondary battery (for example, the open terminal voltage) are grasped in advance, so there is room for improvement in terms of versatility. Further, in the technique described in Patent Document 1, since the charging of the secondary battery is performed intermittently, the charging time may be lengthened.

[0006] Therefore, an object of the present invention is to provide a charging control system or the like that appropriately calculates battery parameters of a battery while suppressing an increase in the charging time required for the battery.

Means for Solving the Problem

[0007] In order to solve the above-described problems, the present invention includes charge control means for calculating a predetermined battery parameter of the battery based on the state of the battery when the battery is intermittently charged. The charge control means performs the next intermittent charge at a timing different from the current intermittent charge, and the timing is set based on the charge rate, voltage, or internal resistance of the battery when charging is temporarily stopped during the intermittent charging of the battery.

Effect of the Invention

[0008] According to the present invention, it is possible to provide a charge control system or the like that appropriately calculates the battery parameters of the battery while suppressing an increase in the time required for charging the battery.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6A

Figure 6B

Figure 7

Figure 8A

Figure 8B

Figure 9

Figure 10

Figure 11

Figure 12A

Figure 12B

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Mode for Carrying Out the Invention

[0010] ≪First Embodiment≫ <Configuration of Charging Control System> FIG. 1 is a configuration diagram including a charging control system 100 according to the first embodiment. Among the lines connecting each configuration in FIG. 1, solid lines indicate power lines and dashed lines indicate signal lines. The charging control system 100 is a system that controls the charging of the battery 21 of the vehicle 20 (mobile object). Further, the charging control system 100 also has a function of estimating characteristics such as the degradation rate (State of Health: SOH) of the battery 21. Hereinafter, prior to the description of the charging control system 100, the vehicle 20 as an example of a mobile object including railways, ships, etc. will be briefly described.

[0011] The vehicle 20 is a land vehicle that runs on power such as that from the battery 21. Examples of such a vehicle 20 include an electric vehicle and a plug-in hybrid vehicle. As shown in FIG. 1, the vehicle 20 includes a battery 21, an inverter 22, a motor 23, and an insertion port 24 for a charging plug (not shown). The battery 21 is a secondary battery capable of charging and discharging. As shown in FIG. 1, the battery 21 is connected to the insertion port 24 via a wiring 25, and is connected to the inverter 22 via the wiring 25 (a part) and the wiring 26 in sequence.

[0012] The inverter 22 is a power converter that converts DC power into AC power. That is, the inverter 22 converts the DC power supplied from the battery 21 into AC power, and outputs the converted AC power to the motor 23. The motor 23 is a drive source of the vehicle 20, and is connected to the inverter 22 via a three-phase wiring 27. The insertion port 24 is a connection part into which a charging plug (not shown) is inserted when charging the battery 21. When the charging plug is inserted into the insertion port 24, the battery 21 and the charger 10 are electrically connected.

[0013] The charger 10 is a device that charges the battery 21. Further, the charger 10 also has a function of estimating the degradation rate of the battery 21 based on the measured values of current and voltage and the state of charge (SOC) during the process of charging the battery 21. In the example of FIG. 1, the charging control system 100 is configured to include the charger 10, but may further include one or more servers (not shown) capable of communicating with the charger 10.

[0014] As shown in FIG. 1, the charger 10 includes a charging control means 1, a voltage measuring means 2, a current measuring means 3, and a charging circuit 4, and is driven by the power supplied from a commercial power supply E (three-phase AC power supply). The voltage measuring means 2 measures the voltage of the battery 21. The current measuring means 3 measures the charging current supplied from the charging circuit 4 to the battery 21. The charging circuit 4 generates a charging current at a predetermined value based on a current command from the charging control means 1.

[0015] As a hardware configuration, the charging control means 1 includes electronic circuits such as a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and various interfaces, although not shown in the figure. Then, the program stored in the ROM is read out and expanded in the RAM, and the CPU executes various processes. The charging control means 1 generates a current command for charging based on the measured values of the voltage measuring means 2 and the current measuring means 3 in addition to the charging current command value transmitted from the vehicle 20 to the charger 10, and outputs the generated current command to the charging circuit 4.

[0016] For example, when the vehicle 20 is managed by a predetermined operation management system (not shown), on the operation management system side, it is required to grasp the remaining travelable distance of the vehicle 20 based on the deterioration state of the battery 21 and appropriately set the travel route of the vehicle 20. However, it is often difficult to obtain in advance on the operation management system side the characteristic data such as the open circuit voltage (OCV) and the internal resistance related to the deterioration state of the battery 21.

[0017] Therefore, in the first embodiment, the charging control means 1 calculates a predetermined "battery parameter" of the battery 21 based on the "state quantity" of the battery 21 when the charging of the battery 21 of the vehicle 20 (mobile body) is intermittently performed. The above-mentioned "state quantity" includes the voltage, charging current, and SOC of the battery 21. The "battery parameter" is, for example, the OCV or internal resistance of the battery 21. The OCV of the battery 21 is the stable voltage at no load (or when almost no current is flowing) in the battery 21. The calculated battery parameter is used, for example, to calculate the state, degree of deterioration, and life of the battery (battery 21).

[0018] Figure 2 is a functional block diagram of the charging control means 1. As shown in FIG. 2, the charge control means 1 includes a battery state estimation unit 11, a charge stop condition determination unit 12, a charge control unit 13, and a storage unit 14. The battery state estimation unit 11 calculates a predetermined battery parameter indicating the state (characteristics) of the battery 21. For example, the battery state estimation unit 11 intermittently charges the battery 21, and acquires the voltage of the battery 21 when a predetermined time has elapsed after temporarily stopping the charging as the OCV. Further, the battery state estimation unit 11 calculates the internal resistance of the battery 21 based on the state quantities (voltage, charging current, and SOC) during the process in which the charging of the battery 21 is intermittently performed.

[0019] The charge stop condition determination unit 12 determines a charge stop condition, which is a condition for temporarily stopping the charging when the battery 21 is intermittently charged. Here, the "charge stop condition" is the SOC (or the voltage of the battery 21) that serves as a threshold value when the charging of the battery 21 is temporarily stopped. And each time the charge control unit 13 temporarily stops the charging of the battery 21, the battery state estimation unit 11 calculates battery parameters such as the OCV and the internal resistance corresponding to the SOC at that time.

[0020] The charge control unit 13 has a function of transmitting to the vehicle 20 (see FIG. 1) the value of the chargeable current, which is the upper limit value of the charging current of the battery 21. On the vehicle 20 side, the charge current command value is reset as necessary so that the charge current command value is equal to or less than the chargeable current. The charge control unit 13 outputs a predetermined charge command to the charge circuit 4 (see FIG. 1) based on the charge current command value transmitted from the vehicle 20 and the SOC of the battery 21.

[0021] A parameter table 14a is stored in the storage unit 14. The parameter table 14a is a table in which battery parameters such as the OCV and the internal resistance of the battery 21 are stored in association with the identification information of the battery 21. As described above, the battery parameters are the OCV and the internal resistance of the battery 21, and are calculated by the battery state estimation unit 11.

[0022] FIG. 3 is a functional block diagram of the charge control unit 13 included in the charge control means. As shown in FIG. 3, the charge control unit 13 includes a charger operation change unit 13a and a charge current determination unit 13b. The charger operation change unit 13a switches the operation of the charger 10 (see FIG. 1) as prescribed based on the charge stop condition input from the charge stop condition determination unit 12 (see FIG. 2) and the SOC received from the vehicle 20 (see FIG. 1).

[0023] For example, when the SOC of the battery 21 (see FIG. 1) reaches the threshold value defined by the charge stop condition, the charger operation change unit 13a temporarily stops charging the battery 21 by reducing the charger output from a predetermined value to 0 [kW]. The charger operation change unit 13a outputs the value of the charger output based on the charge stop condition to the charge current determination unit 13b.

[0024] The charge current determination unit 13b determines the chargeable current in the charger 10 (see FIG. 1) based on the value of the charger output input from the charger operation change unit 13a. For example, the charge current determination unit 13b increases the chargeable current as the charger output increases. Also, when the charger output is 0 [kW], the charge current determination unit 13b sets the chargeable current to 0 [A]. The value of the chargeable current thus determined is transmitted from the charge current determination unit 13b to the vehicle 20 (see FIG. 1). Note that the charge control unit 13 may output a predetermined signal to the charge circuit 4 (see FIG. 1) without particularly changing the chargeable current to temporarily stop charging the battery 21 (see FIG. 1).

[0025] FIG. 19 is a time chart showing changes in the current and voltage of the battery when charging is continuously performed in the comparative example. Note that the horizontal axis in FIG. 19 is time. The vertical axis in FIG. 19 is, in order from the top of the page, the current (charge current) flowing through the battery 21 and the voltage of the battery 21. FIG. 19 shows the waveforms of the current and voltage when so-called constant current constant voltage charge (CCCV charge) is performed. In CCCV charge, when the voltage of the battery 21 reaches the upper limit value V LimUntil reaching that point, CC (Constant Current) charging is performed while maintaining the magnitude of the charging current at a predetermined value, and then CV (Constant Voltage) charging is performed while maintaining the voltage of the battery 21. Note that what charging mode is to be performed during charging of the battery 21 is preset on the vehicle 20 side.

[0026] In the example of FIG. 19, during the CC charging period (time t1 to t2), the charging current command value I transmitted from the vehicle 20 com has a value I2 that is smaller than the chargeable current I p based on the output setting value of the charger 10 (charger output: see FIG. 3). Therefore, during CC charging, the charging current command value I com is set as the current command in the charger 10, and the charging current I ch based on this current command is supplied to the battery 21. Then, at time t2 when the voltage of the battery 21 reaches the upper limit value V Lim , the charging is switched from CC charging to CV charging.

[0027] FIG. 4 is a time chart showing changes in current and voltage when charging of the battery is temporarily stopped (refer to FIG. 1 as appropriate). Note that the downward white arrow W shown in FIG. 4 indicates the timing at which the charger operation changing unit 13a (see FIG. 3) changes the operation of the charger 10. In the example of FIG. 4, during the time t2 to t3 in the middle of CC charging, the chargeable current I p is set to zero, and charging of the battery 21 is temporarily stopped. When charging is thus temporarily stopped, the voltage of the battery 21 rapidly decreases at time t2 and then gradually decreases until time t3 when charging is resumed. Although details will be described later, the measured values such as voltage when charging is temporarily stopped are used for calculating the OCV and internal resistance of the battery 21.

[0028] FIG. 5 is an explanatory diagram of the battery voltage equivalent circuit model 30. The voltage equivalent circuit model 30 shown in FIG. 5 is a model that simulates the internal resistance of the battery 21 (see FIG. 1) with a resistor in an electric circuit and simulates the OCV of the battery 21 with a power supply voltage in order to reproduce the change in the voltage of the battery 21. Ro included in the voltage equivalent circuit model 30 is a resistance component that does not depend on the energization time in the internal resistance of the battery 21 (see FIG. 1). This resistance component Ro corresponds to the member resistance such as the electrodes and the electrolyte of the battery 21. On the other hand, the parallel circuit of Rp and C included in the voltage equivalent circuit model 30 is a resistance component that depends on the energization time in the internal resistance of the battery 21. This resistance component Rp corresponds to the voltage change caused by the electrochemical reaction inside the battery 21 and the internal resistance (polarization resistance) that causes a voltage change due to the diffusion of lithium ions.

[0029] The OCV and the resistance components Ro and Rp of the battery 21 shown in FIG. 5 are battery parameters indicating the characteristics of the battery 21. These battery parameters have different values depending on the magnitude of the SOC of the battery 21. An example thereof will be described with reference to FIGS. 6A and 6B.

[0030] FIG. 6A is an explanatory diagram showing the relationship between the SOC and the OCV when the battery is an NMC-C type battery. Note that the horizontal axis in FIG. 6A is the SOC of the battery 21 (see FIG. 1). The vertical axis in FIG. 6A is the OCV of the battery 21. The above-mentioned NMC-C type battery is a ternary battery using lithium, nickel, and cobalt manganese oxide as a positive electrode material. As shown in FIG. 6A, the OCV curve 41 when the battery 21 is an NMC-C type battery is a smooth curve of monotonically increasing, and as the SOC of the battery 21 increases, the OCV also increases.

[0031] FIG. 6B is an explanatory diagram showing the relationship between the SOC and the OCV when the battery is an LFP-C type battery. As shown in FIG. 6B, even when the battery 21 is an LFP-C battery (lithium iron phosphate battery), as the SOC of the battery 21 increases, the OCV increases, but the way of change is different from that of the NMC-C battery (see FIG. 6A). Specifically, there is a portion 42a where the gradient (positive gradient) of the OCV curve 42 becomes small while the SOC of the battery 21 is increasing. Thus, the shape of the OCV curve differs depending on the type of the battery 21. Note that FIGS. 6A (in the case of the NMC-C battery) and 6B (in the case of the LFP-C battery) do not particularly limit the type of the battery 21.

[0032] Incidentally, even if the type of the battery 21 is the same, there are slight individual differences, and the shape of the OCV curve and the OCV value at each SOC often differ depending on the degree of deterioration. Also, in the operation management system (not shown) and the charge control system 100 of the vehicle 20, it is often difficult to acquire in advance the characteristics of the battery 21 such as the OCV curve. Therefore, in the first embodiment, based on the state quantities (the voltage, charge current, and SOC of the battery 21) in the process of intermittently charging the battery 21, the charge control means 1 calculates the OCV and internal resistance of the battery 21. That is, the OCV curves 41 and 42 shown in FIGS. 6A and 6B are not known ones but are estimated by the charge control means 1.

[0033] FIG. 7 is a time chart showing the changes in current and voltage when the charging of the battery is temporarily stopped. Note that the charging current command value I shown in FIG. 7 com , the charging current I ch , and the way of change of the voltage of the battery 21 are the same as those in FIG. 4. Also, in FIG. 7, although the illustration of the chargeable current I p is omitted, the chargeable current I pIt also changes in the same manner as in FIG. 4. When the charging of the battery 21 is temporarily stopped at times t2 to t3 in FIG. 7, the current of the battery 21 decreases. To explain in more detail, the voltage of the battery 21 rapidly decreases at time t2 and then gradually decreases. The rapid decrease in voltage at time t2 is the voltage drop ΔVo caused by the member resistance of the battery 21. Also, the gradual decrease in voltage from immediately after time t2 is the voltage drop ΔVp associated with the electrochemical reaction of the battery 21 and the diffusion of lithium ions.

[0034] The charge control means 1 (see FIG. 2) acquires the measured value of the voltage of the battery 21 when a predetermined time (the time from time t2 to t3) has elapsed since the time t2 when the charging of the battery 21 was temporarily stopped, as the OCV corresponding to a predetermined SOC. Also, the charge control means 1 (see FIG. 2) calculates a resistance component Ro (see FIG. 5) that does not depend on the energization time of the battery 21 and a resistance component Rp (see FIG. 5) that changes depending on the energization time of the battery 21, based on the following equations (1) and (2).

[0035] Ro = ΔVo / I ··· Equation (1) Rp = ΔVp / I ··· Equation (2)

[0036] In this way, the charge control means 1 calculates the battery parameters (OCV, Ro, Rp) of the battery 21. Note that each battery parameter of the battery 21 changes depending on the SOC of the battery 21. For example, as the SOC of the battery 21 increases, the internal resistance decreases. Therefore, for example, a predetermined SOC that serves as a reference when calculating the internal resistance of the battery 21 is often set in advance. The charge control means 1 calculates the overall internal resistance R1 of the battery 21 by taking the sum of the resistance components Ro and Rp at the predetermined SOC serving as the reference.

[0037] FIG. 20 is a time chart showing changes in the current, voltage, and SOC of a battery when charging is performed intermittently in another comparative example. Note that the horizontal axis of FIG. 20 represents time. The vertical axis of FIG. 20 represents, in order from the top of the paper surface, the charging current of the battery 21, the voltage of the battery 21, and the SOC of the battery 21. In the example of FIG. 20, the SOC thresholds SOC11, SOC12, ··· when charging the battery 21 intermittently are set at relatively small intervals (for example, every 5% in terms of SOC). Then, for example, charging is performed from time t1 (charging is "ON"), and charging is temporarily stopped (charging is "OFF") at time t2 when the SOC of the battery 21 reaches the threshold SOC11. And charging is resumed at time t3. When the interval of the SOC when charging the battery 21 intermittently in this way (that is, the difference between adjacent SOC thresholds) is set finely, the time required to reach full charge becomes longer accordingly. On the other hand, if the interval of the SOC when charging the battery 21 intermittently is too long, the accuracy when estimating the characteristics of the battery 21 will decrease.

[0038] Therefore, in the first embodiment, the charge control means 1 sets the interval of the SOC when performing the first intermittent charging of the battery 21 to be longer (coarser), and in the second intermittent charging, charging is temporarily stopped at a timing different from that during the first intermittent charging. That is, in the first embodiment, the charge control means 1 estimates the battery parameters of the battery 21 based on the data obtained by performing intermittent charging of the battery 21 twice in total. Thereby, the time required for charging can be shortened, and the battery parameters of the battery 21 can be estimated with high accuracy.

[0039] FIGS. 8A and 8B are flowcharts of the processes executed by the charge control means (refer to FIGS. 1 and 2 as appropriate). Note that it is assumed that when "START" in FIG. 8A, a charging plug (not shown) is inserted into the insertion port 24 (refer to FIG. 1) of the vehicle 20 (refer to FIG. 1), and communication is started between the charger 10 and the vehicle 20. In step S101, the charging control means 1 acquires the identification information of the battery 21. That is, the charging control means 1 communicates with the vehicle 20 to acquire the predetermined identification information assigned to the battery 21. Note that the identification information of the vehicle 20 may be used instead of the identification information of the battery 21.

[0040] In step S102, the charging control means 1 determines whether this is the first intermittent charging in the most recent predetermined period. That is, the charging control means 1 determines whether intermittent charging for estimating the battery parameters of the battery 21 has not been performed within a past predetermined period (for example, within several months). This predetermined period is a period in which the deterioration of the battery 21 is likely to progress (that is, the characteristics of the battery 21 are changing), and is set in advance. Every time this predetermined period elapses, a total of two intermittent chargings are performed. In step S102, if this is the first intermittent charging (S102: Yes), the process of the charging control means 1 proceeds to step S103.

[0041] In step S103, the charging control means 1 sets the timing of charging suspension. That is, the charging control means 1 sets the SOC interval when intermittently charging the battery 21 by the charge stop condition determination unit 12 (see FIG. 2). For example, the charging control means 1 sets a longer SOC interval in intermittent charging, such as suspending charging every 20% of the SOC interval. This SOC interval may be set in advance or may be changed as appropriate.

[0042] For example, based on the congestion level of a charging station (not shown) provided with the charger 10, the charging control means 1 may change the SOC interval in intermittent charging. That is, when the charging control means 1 temporarily stops charging every time the charging rate of the battery 21 increases by a first predetermined value, the charging control means 1 may change the first predetermined value based on the allowable time when performing the first (this time) intermittent charging. Specifically, the charging control means 1 increases the first predetermined value as the allowable time for charging is shorter. As a result, the number of times the charging of the battery 21 is temporarily stopped decreases, and the battery 21 reaches a fully charged state in a relatively short time. Consequently, the charging control means 1 can complete the charging of the battery 21 within a predetermined allowable time.

[0043] In step S104, the charging control means 1 executes the charging of the battery 21. That is, the charging control means 1 outputs a predetermined charging command to the charging circuit 4 (see FIG. 1) based on the charging current command value transmitted from the vehicle 20, thereby executing the charging of the battery 21. As the charging of the battery 21 progresses, the SOC of the battery 21 increases.

[0044] In step S105, the charging control means 1 determines whether the SOC of the battery 21 has reached a predetermined threshold value. This predetermined threshold value (for example, the predetermined threshold values SOC1, SOC2, SOC3 shown in FIG. 9) is the threshold value of SOC that serves as a criterion for determining whether to temporarily stop the charging of the battery 21 and is set in the process of step S103. In step S105, when the SOC of the battery 21 has not reached the predetermined threshold value (S105: No), the charging control means 1 continues charging (S104). Also, in step S103, when the SOC of the battery 21 has reached the predetermined threshold value (S105: Yes), the process of the charging control means 1 proceeds to step S106.

[0045] In step S106, the charging control means 1 temporarily stops charging the battery 21. That is, the charging control means 1 controls the charging circuit 4 (see FIG. 1) so that the charging current of the battery 21 becomes substantially zero. In this case, the charging control means 1 may lower the value of the chargeable current of the battery 21 to zero. As described above, since the charging current command value transmitted from the vehicle 20 to the charger 10 is reset to a value equal to or less than the chargeable current (see FIG. 2) transmitted from the charger 10 to the vehicle 20, the charging current command value reaches its peak and is forcibly lowered to zero. Even in such a method, charging of the battery 21 can be temporarily stopped.

[0046] In step S107, the charging control means 1 acquires each measurement value. That is, the charging control means 1 acquires measurement values of state quantities including the voltage of the battery 21 measured by the voltage measurement means 2, the charging current measured by the current measurement means 3, and the SOC of the battery 21 transmitted from the vehicle 20. Each measurement value acquired in step S105 is stored in the storage unit 14 (see FIG. 2) in association with the identification information of the battery 21.

[0047] In step S108, the charging control means 1 calculates the battery parameters of the battery 21. That is, the charging control means 1 acquires the voltage of the battery 21 after a predetermined time has elapsed since the charging of the battery 21 was temporarily stopped as the OCV. Then, the charging control means 1 stores the OCV of the battery 21 in association with the SOC in the parameter table 14a (see FIG. 2). Regarding the internal resistance of the battery 21, it may be calculated at each SOC having a different magnitude (Second Embodiment), but in the First Embodiment, the internal resistance is calculated at a predetermined reference SOC.

[0048] In step S109, the charge control means 1 determines whether the battery 21 is fully charged. In step S109, if the battery 21 is not fully charged (S109: No), the process of the charge control means 1 returns to step S104 to resume charging the battery 21. In this way, the charge control means 1 intermittently charges the battery 21 and calculates battery parameters based on the current, voltage, and SOC when charging is temporarily stopped.

[0049] In step S109, if the battery 21 is fully charged (S109: Yes), the process of the charge control means 1 proceeds to step S110. Note that it is not particularly necessary for the battery 21 to be fully charged, and charging may be completed at an SOC lower than full charge, such as 90% SOC. In step S110, the charge control means 1 completes the first intermittent charge of the battery 21.

[0050] Figure 9 is a time chart for the first intermittent charge. Note that the horizontal axis of Figure 9 is time. The vertical axis of Figure 9 is, in order from the top of the page, the charging current of the battery 21, the voltage of the battery 21, and the SOC of the battery 21. The predetermined threshold values SOC1, SOC2, and SOC3 shown in Figure 9 are the threshold values (the predetermined threshold values in S105 of Figure 8A) used as the determination criteria when temporarily stopping charging, and are set in the process of step S103. For example, in the first (this time) intermittent charge, the charge control means 1 temporarily stops charging each time the SOC (charge rate) of the battery 21 increases by a first predetermined value. The above-mentioned first predetermined value is, for example, within the range of 10% or more and 50% or less.

[0051] By making the interval of the SOC relatively large when performing charging intermittently in this way, the number of times of suspension is reduced, so that the time required for charging can be shortened. In FIG. 9, the interval of the SOC when charging is suspended is set to be equal intervals, but it may be unequal intervals. As shown in FIG. 9, the OCV of the battery 21 is measured at each measurement point K1 to K5. That is, the charging control means 1 acquires the voltage value of the measurement point K1 at the start of charging of the battery 21 as the OCV, and also acquires the voltage values of the measurement points K2 to K5 when a predetermined time has elapsed after charging is suspended as the OCV.

[0052] FIG. 10 is an explanatory diagram showing the relationship between the SOC and the OCV of the battery. Note that the horizontal axis in FIG. 10 is the SOC of the battery 21, and the vertical axis is the OCV of the battery 21. The black circles in FIG. 10 are the measurement points of the OCV obtained by the first intermittent charging. The black squares in FIG. 10 are the measurement points of the OCV obtained by the second intermittent charging. By measuring the OCV at the five measurement points K1 to K5 shown in FIG. 9, the data of the five black circles (measurement points K1 to K5) shown in FIG. 10 are obtained. The data of these measurement points K1 to K5 are the actual OCV corresponding to the SOC of the battery 21.

[0053] In step S102 of FIG. 8A, when this is not the first intermittent charging (S102: No), the process of the charging control means 1 proceeds to step S111 of FIG. 8B. For example, when this is the second intermittent charging, the process of the charging control means 1 proceeds to step S111. As described above, in the first embodiment, the charging control means 1 performs intermittent charging twice in total to create a predetermined parameter table 14a (see FIG. 2).

[0054] In step S111 of FIG. 8B, the charging control means 1 sets the timing of temporarily stopping charging. That is, the charging control means 1 sets the SOC threshold value when temporarily stopping the charging of the battery 21 by the charging stop condition determination unit 12 (see FIG. 2). When setting such an SOC threshold value, the charging control means 1 reads the data of the measurement points K1 to K5 (see FIG. 10) obtained during the first intermittent charging. Then, the charging control means 1 calculates the differences in OCV at adjacent measurement points respectively.

[0055] In the example of FIG. 10, the difference Δα in OCV between the measurement points K1 and K2 is relatively large, and the difference Δβ in OCV between the measurement points K4 and K5 is also relatively large. For those where the difference in OCV at adjacent measurement points is equal to or greater than a predetermined value (second predetermined value), the charging control means 1 sets the SOC of a new measurement point (the measurement point when temporarily stopping charging) so as to supplement the data therebetween. That is, by performing the next measurement at a location where the sensitivity of OCV to changes in SOC is high, the data indicating the characteristics of OCV is extracted without waste.

[0056] In this way, among the plurality of timings (SOC) for temporarily stopping charging in the first (this time) intermittent charging, for those where the difference in OCV (open circuit voltage) of the battery 21 at adjacent timings is equal to or greater than a predetermined value (second predetermined value), the charging is temporarily stopped at another timing between the adjacent timings in the next intermittent charging. In the first intermittent charging, for those where the difference in OCV between adjacent measurement points is equal to or greater than a predetermined value, for example, the midpoint between the SOCs of adjacent measurement points (for example, SOC0 and SOC1 in FIG. 10) may be used as the timing for temporarily stopping charging, or it may be a point other than the midpoint.

[0057] On the one hand, the difference in OCV between the measurement points K2 and K3 shown in FIG. 10 is relatively small, and the difference in OCV between the measurement points K3 and K4 is also relatively small. Thus, for those where the difference in OCV between adjacent measurement points is less than a predetermined value (second predetermined value), there is no particular problem even if it is considered that the OCV increases linearly between adjacent measurement points, so there is no particular need to obtain a new measurement point. Therefore, in the second intermittent charging, the charging control means 1 continues charging without temporarily stopping it in this section (for example, the SOC section between the measurement points K2 and K3).

[0058] Thus, among the plurality of timings (SOC) at which the charging control means 1 temporarily stops charging in the first (this time) intermittent charging, for those where the difference in the OCV (open circuit voltage) of the battery 21 between adjacent timings is less than the second predetermined value, between the adjacent timings, the next charging is continued without being temporarily stopped. Thereby, it is possible to prevent the temporary stop of charging from being performed uselessly, and ultimately, the time required for charging can be shortened. Note that the above-described second predetermined value is a threshold value of the OCV width serving as a determination criterion for whether it is necessary to obtain a new measurement point and is set in advance.

[0059] In step S112 of FIG. 8B, the charging control means 1 executes charging of the battery 21. Next, in step S113, the charging control means 1 determines whether the SOC of the battery 21 has reached a predetermined threshold value. This predetermined threshold value is a threshold value of the SOC serving as a determination criterion for whether to temporarily stop charging of the battery 21 and is set in the process of step S111. In step S113, if the SOC of the battery 21 has not reached the predetermined threshold value (S113: No), the charging control means 1 continues charging (S112). Also, in step S113, if the SOC of the battery 21 has reached the predetermined threshold value (S113: Yes), the process of the charging control means 1 proceeds to step S114.

[0060] In step S114, the charging control means 1 temporarily stops charging of the battery 21. In step S115, the charging control means 1 acquires each measurement value. That is, the charging control means 1 acquires measurement values of state quantities including the voltage, charging current, and SOC of the battery 21. Each measurement value acquired in step S105 is stored in the storage unit 14 (see FIG. 2) in association with the identification information of the battery 21.

[0061] In step S116, the charging control means 1 calculates the battery parameters of the battery 21. As described above, the battery parameters of the battery 21 include the OCV. In step S117, the charging control means 1 determines whether the battery 21 is fully charged. In step S117, if the battery 21 is not fully charged (S117: No), the charging control means 1 resumes charging (S112). Also, in step S117, if the battery 21 is fully charged (S117: Yes), the process of the charging control means 1 proceeds to step S118.

[0062] In step S118, the charging control means 1 completes the second intermittent charging of the battery 21. After performing the process of step S118, the charging control means 1 ends a series of processes related to charging (END).

[0063] FIG. 11 is a time chart regarding the second intermittent charging. The predetermined threshold values SOC6 and SOC7 shown in FIG. 11 are threshold values (the predetermined threshold values in S113 of FIG. 8B) serving as criteria for temporarily stopping charging, and are set in the process of step S111. By the charging control means 1 temporarily stopping charging at the predetermined threshold values SOC6 and SOC7 and measuring (calculating) the OCV, etc. of the battery 21, the data of the measurement points M6 and M7 shown in FIG. 11 can be obtained. Thus, the charging control means 1 performs the second (next) intermittent charging at a timing different from that of the first (this time) intermittent charging. The above-mentioned "timing" is set based on the charging rate (or voltage or internal resistance) of the battery 21 when temporarily stopping charging in the intermittent charging of the battery 21.

[0064] In the example of FIG. 11, since the number of times of charging suspension is two times in total, the time required to fully charge the battery 21 can be shortened. Further, by appropriately setting the predetermined threshold values SOC6 and SOC7 by the charge control means 1 (S111 in FIG. 8B), battery parameters such as the OCV of the battery 21 can be calculated. The OCV data at the measurement points M6 and M7 shown in FIG. 11 is stored in the parameter table 14a (see FIG. 2) in association with the SOC values. As a result, each cell of the parameter table 14a is filled.

[0065] For example, the charge control means 1 may specify the OCV curve 43 by performing a predetermined curve approximation based on the measurement points K1 to K5 and the measurement points M6 and M7 shown in FIG. 10. The data regarding the OCV curve 43 is used for calculating the degradation rate (State of Health: SOH) etc. of the battery 21. Specifically, when charging the battery 21 again after specifying the OCV curve 43, the charge control means 1 calculates the battery capacity based on the voltage Va of the battery 21 at the start of charging (see FIG. 7), the voltage Vb of the battery 21 when charging is suspended (see FIG. 7), and the integrated current amount therebetween. Then, based on the SOC at the start of charging, the SOC when charging is suspended, and the above-described battery capacity, the charge control means 1 calculates the degradation rate of the battery 21. Note that instead of the charge control means 1, a server (not shown) that communicates with the charger 10 may perform the calculation of the degradation rate etc.

[0066] Note that after the creation of the parameter table 14a (see FIG. 2) is completed, for a predetermined period (for example, several months), the operation management system (not shown) of the vehicle 20 may set the driving route of the battery 21 etc. based on the parameter table 14a. During this predetermined period, when the charger 10 charges the battery 21, normal continuous charging may be performed, and there is no particular need to perform intermittent charging. Then, when a predetermined period has elapsed since the two intermittent chargings were performed and there is a possibility that the degradation of the battery 21 has progressed, the charge control means 1 updates the battery parameters by performing intermittent charging again.

[0067] <Effect> According to the first embodiment, based on the voltage, current, and SOC during the process in which the charging control means 1 intermittently charges the battery 21, battery parameters such as the OCV and internal resistance of the battery 21 can be calculated with high precision. Also, by performing the intermittent charging in two separate times by the charging control means 1, it is possible to suppress the charging time from becoming too long. Therefore, according to the first embodiment, while suppressing the charging time of the battery 21 from becoming long, the charging control means 1 can appropriately calculate the battery parameters of the battery 21.

[0068] Also, when the charging control means 1 performs the second intermittent charging, based on the battery parameters in the first intermittent charging, the timing of temporarily stopping the charging is set (S111 in FIG. 8B). Thereby, the charging control means 1 can obtain the battery parameters at this location by temporarily stopping the charging of the battery 21 at a location where the sensitivity of battery parameters such as OCV is high. Also, even when the type and material of the battery 21 are unknown, since the charging control means 1 can estimate the battery parameters, the versatility of the charging control system 100 can be enhanced.

[0069] Also, for example, when the vehicle 20 is an EV truck for logistics distribution and is managed by a predetermined operation management system (not shown), based on the battery parameters, the degree of deterioration of the battery 21 can be grasped on the operation management system side. Thereby, the operation management system can accurately estimate the remaining travelable distance of the vehicle 20 and appropriately set the planned travel route of the vehicle. Therefore, according to the first embodiment, it is possible to achieve both suppression of a decrease in the operation efficiency of the vehicle 20 and ensuring the detection accuracy of the battery parameters.

[0070] ≪Second Embodiment≫ In the second embodiment, in the process where the charging control means 1 (see FIG. 2) intermittently charges the battery 21, it is different from the first embodiment in that the internal resistance (Direct Current Resistance: DCR) of the battery 21 corresponding to each SOC is calculated. Also, in the second embodiment, the processing executed by the charging control means 1 is the same as that in the first embodiment (see FIGS. 8A and 8B), but the difference is that the charging control means 1 calculates the DCR instead of (or together with) calculating the OCV. Note that the rest (such as the configuration of the charging control system 100: see FIGS. 1 to 3) is the same as that in the first embodiment. Therefore, the parts different from the first embodiment will be described, and the description of the overlapping parts will be omitted.

[0071] FIG. 12A is an explanatory diagram showing the relationship between the SOC and the DCR when the battery is an NMC-C system battery. Note that the horizontal axis in FIG. 12A is the SOC of the battery 21 (see FIG. 1). The vertical axis in FIG. 12A is the DCR (internal resistance) of the battery 21. As shown in FIG. 12A, in the DCR curve 51 of the NMC-C system battery, as the SOC of the battery 21 increases, the DCR of the battery 21 decreases.

[0072] FIG. 12B is an explanatory diagram showing the relationship between the SOC and the DCR when the battery is an LFP-C system battery. As shown in FIG. 12B, in the DCR curve 52 of the LFP-C system battery, as the SOC of the battery 21 increases from a zero value, the DCR decreases, then once increases, and then decreases again. Thus, depending on the type of the battery 21, the shape of the DCR curve becomes different.

[0073] FIG. 13 is a time chart regarding the first intermittent charging in the charging control system according to the second embodiment. In the example of FIG. 13, charging is sequentially paused temporarily when the SOC of the battery 21 reaches predetermined threshold values SOC1, SOC2, and SOC3. Then, based on the voltage change amount ΔV (rise amplitude at the rising edge) at times t2, t4, and t6 when charging is paused temporarily, in addition to the time t0 when charging starts, the charging control means 1 calculates the internal resistance at each SOC.

[0074] FIG. 14 is an explanatory diagram showing the relationship between the SOC and DCR of the battery. Note that the horizontal axis in FIG. 14 is the SOC of the battery 21, and the vertical axis is the DCR (internal resistance) of the battery 21. The black circles shown in FIG. 14 are the measurement points of the DCR obtained in the first intermittent charging. Also, the black squares shown in FIG. 14 are the measurement points of the DCR obtained in the second intermittent charging. By measuring the DCR at the four measurement points A1 to A4 in FIG. 13, the data of the four black circles (measurement points A1 to A4) in FIG. 14 are obtained. The data of these measurement points A1 to A4 are the actual DCR data corresponding to the SOC of the battery 21.

[0075] In the example of FIG. 14, the difference Δη in the DCR between the measurement points A1 and A2 is relatively large. Thus, for those where the difference in the DCR between adjacent measurement points is equal to or greater than a predetermined value (the third predetermined value), the charging control means 1 sets the SOC of a new measurement point (the measurement point when charging is paused temporarily) so as to supplement the data therebetween. That is, by performing the next measurement at a location where the sensitivity of the DCR to changes in the SOC is high, the data indicating the characteristics of the DCR are extracted without waste.

[0076] In this way, among the plurality of timings (SOC) at which charging is paused temporarily in the first (this time) intermittent charging, for those where the difference in the DCR (internal resistance) of the battery 21 between adjacent timings is equal to or greater than a predetermined value (the third predetermined value), the charging control means 1 pauses charging temporarily in the second (next) intermittent charging at another timing between the adjacent timings.

[0077] On the one hand, the difference in DCR between measurement points A2 and A3 is relatively small, and the difference in DCR between measurement points A3 and A4 is also relatively small. Thus, for those where the difference in DCR between adjacent measurement points is less than a predetermined value (the third predetermined value), there is no particular problem even if it is considered that the DCR increases linearly between adjacent measurement points. Therefore, there is no particular need to obtain a new measurement point. Accordingly, during the second intermittent charging, the charge control means 1 continues charging without temporarily stopping in this section (for example, the SOC section between measurement points A2 and A3).

[0078] In this way, among the multiple timings (SOC) at which the charge control means 1 temporarily stops charging during the first (this time) intermittent charging, for those where the difference in DCR (internal resistance) of the battery 21 between adjacent timings is less than a predetermined value (the third predetermined value), during the period between the adjacent timings, the second (next time) charging is continued without being temporarily stopped. Thereby, it is possible to prevent the temporary stop of charging from being performed uselessly and shorten the time required for charging. In this way, the charge control means 1 performs the next intermittent charging at a timing different from the current intermittent charging during the charging of the battery 21. The above-mentioned timing is set based on the DCR (internal resistance) of the battery 21 when temporarily stopping charging during the intermittent charging of the battery 21.

[0079] FIG. 15 is a time chart regarding the second intermittent charging. In the example of FIG. 15, in addition to the predetermined threshold value SOC1, the charging is temporarily stopped at the predetermined threshold value SOC5, and the change amount ΔV of the voltage of the battery 21 at time t2 is measured. As a result, the DCR at the measurement point B5 in FIG. 14 is calculated. The DCR data at the measurement point B5 obtained by the second intermittent charging is stored in the parameter table 14a (see FIG. 2) in association with the SOC. Thereby, each cell of the parameter table 14a is filled. In the second embodiment, although the case where the DCRs at a plurality of SOCs with different magnitudes are calculated has been described, in addition to this, the OCV at each SOC may be measured.

[0080] <Effect> According to the second embodiment, the charging control means 1 can calculate the DCR of the battery 21 with high accuracy based on the measured values of voltage and current and the SOC during the process of intermittently charging the battery 21. Further, by performing the intermittent charging in two steps, the charging control means 1 can suppress the charging time from becoming too long.

[0081] ≪Third Embodiment≫ The third embodiment is different from the first embodiment in that a plurality of chargers 10 (see FIG. 16) are connected to the charging station 60 (see FIG. 16). Further, the third embodiment is different from the first embodiment in that when a plurality of chargers 10 intermittently charge the battery 21, the timing is shifted from that of the other chargers 10. Note that the configuration of each charger 10 is the same as that of the first embodiment (see FIGS. 1 to 3). Therefore, the parts different from the first embodiment will be described, and the description of the overlapping parts will be omitted.

[0082] FIG. 16 is a configuration diagram including a charging control system 100A according to the third embodiment. As shown in FIG. 16, the charging control system 100A includes a plurality of chargers 10 and a charging station 60. The plurality of chargers 10 each perform charging of the battery 21 of the vehicle 20. The charging station 60 supplies the power supplied from the commercial power supply E to the plurality of chargers 10 and exchanges data with the plurality of chargers 10. As shown in FIG. 16, the charging station 60 is connected to each of the plurality of chargers 10 via a charging cable 70.

[0083] Note that part or all of the functions of the charging control means 1 (see FIG. 2) for controlling the charging of the battery 21 may be performed by the charging station 60. For example, when the plurality of chargers 10 perform intermittent charging, the charging station 60 may set the timing for temporarily stopping the charging. Hereinafter, as an example, a case where three chargers 10 intermittently charge the battery 21 in parallel will be described, but the number of chargers 10 performing charging in parallel is not particularly limited.

[0084] Figure 21 is a time chart showing the change in the total power of a total of three chargers and the change in the power used by each charger in the comparative example. Note that the horizontal axis of FIG. 21 is time. The vertical axis of FIG. 21 shows, in order from the top of the page, the total power of a total of three chargers 10, the power used by the first charger 10, the power used by the second charger 10, and the power used by the third charger 10.

[0085] In the comparative example of FIG. 21, each of the three chargers 10 continuously charges from time t0 and finishes charging when it is fully charged at time t1. When charging is continuously performed in parallel with a plurality of chargers 10 in this way, the total power at each moment from time t0 to t1 when charging is executed increases. In the comparative example of FIG. 21, the total power from time t0 to t1 exceeds a predetermined upper limit value P1 (for example, the contract power). Therefore, in the third embodiment, the plurality of chargers 10 perform intermittent charging with shifted timings so that the total power of the three chargers 10 does not exceed the upper limit value P1.

[0086] Figure 17 is a time chart showing the change in the power used by each charger and the change in the total power in the third embodiment. In the example of FIG. 17, each of the three chargers 10 intermittently charges the battery 21. In this way, when the battery 21 of the vehicle 20 (mobile body) is connected one-to-one to a plurality of chargers 10 provided in the charging station 60 (see FIG. 16), the charge control means 1 (see FIG. 1) intermittently charges with each charger 10. Also, the number of chargers 10 among the plurality of chargers 10 whose charging time zones overlap is less than the total number of the plurality of chargers 10. In the example of FIG. 17, among the three chargers 10, the number of chargers 10 whose charging time zones overlap is two. As a result, the total power of the three chargers 10 in total is suppressed below the upper limit value P1, so that the power cost at the charging station 60 can be reduced.

[0087] Regarding FIG. 17, from another perspective, when some of the plurality of chargers 10 (for example, the first and second chargers 10 in FIG. 17) are performing charging, the charging control means 1 performs a "process" of temporarily stopping the charging by the other chargers 10 (for example, the third charger 10). Here, it is preferable that the charging control means 1 performs the above-mentioned "process" so that the total value of the power consumption of the plurality of chargers 10 becomes equal to or less than a predetermined upper limit value P1. Thereby, the total power of the three chargers 10 in total can be suppressed to be equal to or less than the upper limit value P1.

[0088] In addition, when charging is continuously performed by a plurality of chargers 10 to which the battery 21 is connected, when it is predicted that the total value of the power consumption of the plurality of chargers 10 exceeds a predetermined upper limit value (see FIG. 21), the charging control means 1 may perform the above-mentioned "process". Note that FIG. 17 is an example, and the timing of temporarily stopping charging is not limited to this.

[0089] FIG. 18 is a time chart showing the voltage changes of three batteries. Note that the horizontal axis of FIG. 18 is time. The vertical axis of FIG. 18 shows, in order from the top of the paper surface, the voltage of the battery 21 connected to the first charger 10, the voltage of the battery connected to the second charger 10, and the voltage of the battery connected to the third charger 10. Also, "ON" in FIG. 18 indicates that charging is in progress, and "OFF" indicates that charging is temporarily stopped. The voltage changes of each battery 21 in FIG. 18 correspond to the ON / OFF of charging in FIG. 17.

[0090] The charging control means 1 obtains the OCVs at measurement points F1 and F2 when a predetermined time has elapsed after temporarily stopping the charging of, for example, the battery 21 (corresponding to the upper part of the drawing in FIG. 18) connected to the first charger 10. Further, the charging control means 1 performs the same processing for the battery 21 (corresponding to the middle part of the drawing in FIG. 18) connected to the second charger 10 and the battery 21 (corresponding to the lower part of the drawing in FIG. 18) connected to the third charger 10 (measurement points G1, H1, H2). As a result, the OCVs of each battery 21 can be obtained while suppressing the total power of the three chargers 10 below the upper limit value P1 (see FIG. 17).

[0091] Note that the charging control means 1 may calculate the DCR (internal resistance) in addition to the OCV of the battery 21. Further, among the three batteries 21 connected to the three chargers 10, those in which the first intermittent charging described in the first embodiment is performed and those in which the second intermittent charging is performed may be mixed. Also, one or more of the three batteries 21 in which the measurement of the OCV and the calculation of the DCR are not particularly performed may exist. For example, even if the generation of the parameter table 14a (see FIG. 2) of battery parameters such as OCV and DCR is already completed, intermittent charging may be performed. As described above, by performing intermittent charging, the total power of the plurality of chargers 10 can be suppressed below the upper limit value P1 (see FIG. 17).

[0092] <Effect> According to the third embodiment, since the total power of the plurality of chargers 10 connected to the charging station 60 can be suppressed below a predetermined upper limit value P1, the power cost can be reduced. In addition, while suppressing an increase in the time required for charging each battery 21, the charging control means 1 can appropriately calculate battery parameters such as the OCV and DCR of the battery 21.

[0093] ≪Modification Example≫ As described above, the charging control systems 100, 100A, etc. have been described in each embodiment, but the present invention is not limited to these descriptions, and various modifications can be made. For example, in each embodiment, the case where the charging control means 1 executes intermittent charging based on the SOC of the battery 21 has been described. However, instead of the SOC of the battery 21, the voltage of the battery 21 may be used. That is, each time the voltage of the battery 21 reaches a predetermined threshold value during charging, the charging control means 1 may temporarily stop charging.

[0094] Also, in each embodiment, the case where the charging control means 1 performs intermittent charging of the battery 21 a total of two times has been described. However, the number of times of intermittent charging may be three or more. In this case, the charging control means 1 performs the next (for example, the third) intermittent charging at a timing different from the current (for example, the second) intermittent charging.

[0095] Also, in each embodiment, as examples of the battery parameters of the battery 21, OCV and DCR have been given, but it is not limited thereto. For example, as the battery parameter, the time constant τ of the polarization phenomenon in the battery 21 may be included. In this case, the charging control means 1 calculates the time constant τ as the time required for the voltage drop ΔVp (see FIG. 7) up to a certain point to drop by about 63.2% after the current interruption.

[0096] Further, the charging control means 1 may identify the type of the battery 21 based on the battery parameters obtained by the first (this time) intermittent charging. In this case, the charging control means 1 may set the timing for temporarily stopping the charging in the second (next) intermittent charging based on the battery parameters obtained by the first (this time) intermittent charging and a database of battery parameters that differ according to the type of the battery 21. Note that the data of the OCV curve and DCR curve of the battery 21 are stored in advance in association with the type of the battery 21. In this case, the charging control means 1 sets the timing for temporarily stopping the second (next) charging at, for example, an inflection point such as the OCV curve corresponding to the type of the battery 21 identified based on the battery parameters. Thereby, the charging control means 1 sets the optimal timing for temporarily stopping the charging of the battery 21, and the characteristics of the battery 21 can be appropriately extracted.

[0097] Also, in each embodiment, the case where the charger 10 includes the charging control means 1 (see FIG. 1) has been described, but the present invention is not limited to this. That is, a server (not shown) that communicates with the charger 10 or the charging station 60 may perform at least a part of the functions of the charging control means 1.

[0098] Also, in each embodiment, the case where the charging control means 1 reduces the chargeable current to zero when temporarily stopping (turning off) the charging of the battery 21 has been described, but the present invention is not limited to this. That is, the charging control means 1 may switch the ON / OFF of the charging without particularly changing the chargeable current.

[0099] Also, in each embodiment, the case where the charging control means 1 temporarily stops the charging while performing constant current charging (CC charging) has been described, but the present invention is not limited to this. For example, another charging method such as constant power charging may be used.

[0100] In addition, in each embodiment, the process in which the charging control means 1 calculates the internal resistance of the battery 21 based on the amount of change in current and voltage at the timing of the rise of the charging current has been described, but it is not limited to this. That is, the charging control means 1 may calculate the internal resistance of the battery 21 based on the amount of change in current and voltage at the timing of the fall of the charging current.

[0101] In addition, in each embodiment, the case where the charging control means 1 controls the charging current has been described. However, in addition to charging from the charger 10 to the vehicle 20, each embodiment can also be applied to a bidirectional charger that can also discharge from the vehicle 20 to the charger 10. Note that since the internal resistance of the battery 21 may be different during charging and discharging, when discharging is possible, the internal resistance on the discharge side can also be obtained together to accurately calculate the internal resistance of the battery 21.

[0102] In addition, in the third embodiment, as shown in FIG. 17, the case where charging is intermittently performed with a total of three chargers 10 having their timings shifted by a predetermined amount has been described, but it is not limited to this. For example, a total of two chargers 10 (or two sets of a plurality of chargers each) may alternately switch the ON / OFF of charging over time, or other charging patterns may also be possible.

[0103] Also, the embodiments may be combined as appropriate. For example, the first embodiment and the second embodiment may be combined so that the charging control means 1 calculates (acquires) the OCV of the battery 21 and also calculates the internal resistance. In addition, combinations such as the second embodiment and the third embodiment are also possible.

[0104] In addition, each embodiment has been described for the case where the vehicle 20 is an electric vehicle or a plug-in hybrid vehicle, but it can also be applied to two-wheeled or three-wheeled vehicles driven by electricity. In addition to the vehicle 20, each embodiment can also be applied to "mobile bodies" on land, sea, and air such as railway vehicles on non-electrified lines, ships, aircraft, and agricultural machinery. The aircraft described above includes drones and unmanned aerial vehicles. Also, each embodiment can be applied to a power system energy storage system.

[0105] Also, the process (charging control method) executed by the charging control means 1 or the like may be executed as a predetermined program of a computer. The above-described program can also be provided via a communication line, or can be written on a recording medium such as a CD-ROM and distributed.

[0106] Also, each embodiment is described in detail for the purpose of easily explaining the present invention, and is not necessarily limited to an embodiment having all the configurations described. Also, it is possible to add, delete, or replace a part of the configuration of the embodiment with another configuration. Also, the mechanisms and configurations described above show those considered necessary for explanation, and not all mechanisms and configurations are necessarily shown in the product.

Explanation of Signs

[0107] 1 Charging control means 2 Voltage measurement means 3 Current measurement means 4 Charging circuit 10 Charger 11 Battery state estimation unit 12 Charging stop condition determination unit 13 Charging control unit 13a Charger operation change unit 13b Charging current determination unit 14 Storage unit 14a Parameter table 20 Vehicle (mobile body) 21 Battery 60 Charging station 100, 100A Charging control system

Claims

1. Comprising charge control means for calculating a predetermined battery parameter of the battery based on the state of charge of the battery when intermittently charging the battery, The charge control means performs the next intermittent charge at a timing different from the current intermittent charge, The timing is a charge control system set based on the state of charge, voltage, or internal resistance of the battery when charging is temporarily stopped during intermittent charging of the battery.

2. In the current intermittent charge, the charge control means temporarily stops charging each time the state of charge of the battery increases by a first predetermined value The charge control system according to claim 1, characterized in that.

3. The charge control means changes the first predetermined value based on the allowable time when performing the current intermittent charge The charge control system according to claim 2, characterized in that.

4. The shorter the allowable time, the larger the first predetermined value the charge control means makes The charge control system according to claim 3, characterized in that.

5. The battery parameter includes the open circuit voltage of the battery, Among the multiple timings when charging is temporarily stopped in the current intermittent charge, for those where the difference in the open circuit voltage of the battery between adjacent timings is equal to or greater than a second predetermined value, the charge control means temporarily stops charging at another timing between the adjacent timings during the next intermittent charge The charge control system according to claim 1, characterized in that.

6. The battery parameter includes the open circuit voltage of the battery, Among the multiple timings when charging is temporarily stopped in the current intermittent charge, for those where the difference in the open circuit voltage of the battery between adjacent timings is less than a second predetermined value, the charge control means continues charging without temporarily stopping the next charge between the adjacent timings The charge control system according to claim 1, characterized in that.

7. The battery parameter includes the internal resistance of the battery, Among the multiple timings when charging is temporarily stopped in the current intermittent charge, for those where the difference in the internal resistance of the battery between adjacent timings is equal to or greater than a third predetermined value, the charge control means temporarily stops charging at another timing between the adjacent timings during the next intermittent charge The charge control system according to claim 1, characterized in that.

8. The battery parameters include the internal resistance of the battery. Among the multiple timings at which the charging control means temporarily stops the charging in the current intermittent charging, for those in which the difference in the internal resistance of the battery between adjacent timings is less than a third predetermined value, the charging control means continues the next charging without temporarily stopping it between the adjacent timings. The charging control system according to claim 1, characterized in that.

9. The charging control means identifies the type of the battery based on the battery parameters obtained in the current intermittent charging. The charging control system according to claim 1, characterized in that.

10. The charging control means sets the timing for temporarily stopping the charging in the next intermittent charging based on the battery parameters obtained in the current intermittent charging and the type of the battery. The charging control system according to claim 1, characterized in that.

11. When the battery is connected one-to-one to a plurality of chargers provided at a charging station, the charging control means intermittently charges with each charger, and the number of chargers among the plurality of chargers whose charging time zones overlap is less than the total number of the plurality of chargers. The charging control system according to claim 1, characterized in that.

12. When the battery is connected one-to-one to a plurality of chargers provided at a charging station, the charging control means intermittently charges with each charger, and when some of the plurality of chargers are charging, the charging control means performs a process of temporarily stopping the charging by other chargers. The charging control system according to claim 1, characterized in that.

13. The charging control means performs the process so that the total value of the power consumption of the plurality of chargers is equal to or less than a predetermined upper limit value. The charging control system according to claim 12, characterized in that.

14. When calculating a predetermined battery parameter of the battery based on the state quantity of the battery when charging the battery intermittently, the next intermittent charging is performed at a timing different from the current intermittent charging, and the timing is a charging control method set based on the charging rate, voltage, or internal resistance of the battery when temporarily stopping the charging in the intermittent charging of the battery.

15. A program for causing a computer to execute the charging control method according to claim 14.

Images