Battery charging device

Abstract

To provide a battery charging device that can maximize battery performance while using battery power effectively.SOLUTION: The battery charging device comprises a charger that heats a battery by discharging battery power to an external load.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] The following Patent Document 1 discloses a battery charge control device that reliably achieves the intended setting of a timer-scheduled charging time in relation to the operation of a battery heater while a charger is connected. This battery charge control device runs while a charger is connected, and when the battery is being heated and not during a timer-scheduled charging time, it sets the battery's charge state at the start of battery heating as the battery storage capacity and controls the charging power to the battery so that the battery's SOC is maintained. This battery charge control device also controls the charging power to the battery so that the battery is fully charged during the timer-scheduled charging time, and even if the SOC tends to temporarily deteriorate due to a sudden increase in heater power consumption immediately after heating begins, the battery is fully charged as intended during the timer-scheduled charging time. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-191785 Summary of the Invention [Problem to be solved by the invention]

[0004] However, while the background art can maximize battery performance by heating the battery with a heater, using a heater to heat the battery does not ensure effective use of electric power. In other words, the background art cannot be said to fully utilize battery power.

[0005] The present invention has been made in view of the above circumstances, and has as its object to provide a battery charging device that can maximize battery performance while effectively utilizing battery power. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention employs, as a first solution relating to a battery charging device, a means in which a charger is provided that heats the battery by discharging battery power to an external load.

[0007] The present invention employs a second solution related to a battery charging device, which is the same as the first solution, but further includes an operating unit that outputs the charging time of the battery to the charger, and the charger heats the battery so that the temperature of the battery becomes equal to or higher than a predetermined lower temperature threshold before and after the charging time.

[0008] The present invention provides a third solution related to a battery charging device, which is the same as the second solution, except that the charger further includes a heater for heating the battery, and the charger switches between heating by discharging to the external load and heating by the heater.

[0009] The present invention provides a fourth solution related to a battery charging device, which is the same as the third solution, in which the charger switches between heating by discharging to the external load and heating by the heater based on outside air temperature information and battery status.

[0010] The present invention provides a fifth solution related to a battery charging device, which is the third solution described above, in which the charger switches between heating by discharging to the external load and heating by the heater before and after the charging time.

[0011] The present invention employs a sixth solution relating to a battery charging device, in which in the first or second solution described above, the battery is an on-board battery that supplies power to a motor mounted on a vehicle. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a battery charging device that can maximize battery performance while making effective use of battery power. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a block diagram showing the configuration of a battery charging device according to an embodiment of the present invention; [Figure 2] 3 is a flowchart showing the operation of the battery charging device according to the embodiment of the present invention. [Figure 3] 1 is a flowchart showing a warming schedule according to one embodiment of the present invention. [Figure 4] 4 is a timing chart showing the operation of the battery charging device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1, the battery charging device A according to this embodiment is a device that adjusts the state of charge of a main battery 1 provided in a vehicle M. This battery charging device A is electrically connected between the vehicle M and a house H, and adjusts the state of charge of the main battery 1 by controlling the flow of power between the vehicle M and the house H.

[0015] Such a battery charging device A includes a charger J and a charging time command device K. In addition to a main battery 1, a vehicle M includes a first relay 2, an inverter 3, a motor 4, a heater 5, a second relay 6, a battery charge state detection sensor 7, a battery temperature sensor 8, a relay drive circuit 9, and a control device 10. Furthermore, a house H includes an external load h1 and a control device h2.

[0016] The charger J has a power terminal, a pair of first input / output terminals, a pair of second input / output terminals, four input terminals, and one output terminal. The power terminals of the charger J are connected to a commercial power source drawn into the house H. Furthermore, the pair of first input / output terminals of the charger J are connected to a first relay 2 in the vehicle M, and the pair of second input / output terminals are connected to an external load h1 in the house H.

[0017] Moreover, the charger J has a first input terminal connected to the output terminal of the charge time command device K, a second input terminal connected to an external load, a third input terminal connected to the second output terminal of the control device 10 in the vehicle M, and a fourth input terminal connected to the output terminal of the control device h2 in the house H. Furthermore, the output terminal of the charger J is connected to the third input terminal of the control device 10.

[0018] Such a charger J is a charge control device that executes a pre-stored charge control program to control charging and discharging of the main battery 1 provided in the vehicle M. The charger J has, as its basic function, a power conversion function that converts commercial power (AC power) supplied from a commercial power source into charging power (DC power).

[0019] For example, the charger J outputs the charging power to the vehicle M from a pair of first input / output terminals based on the charging time input from the charging time command device K. When the charging power is output from the pair of first input / output terminals, the charger J outputs a higher-level control command from the output terminal to the control device 10, thereby causing the charging power to be charged into the main battery 1.

[0020] The charger J also exchanges information with the control device 10 of the vehicle M and the control device h2 of the house H in a predetermined communication format. The charger J also acquires outside temperature information from external devices based on communication with the external devices. The charger J controls charging of the main battery 1 based on the charging time input from the charge time command device K, the outside temperature information received from the external devices, the battery state signal input from the control device 10, and the charge / discharge enable / disable signal input from the control device h2.

[0021] Furthermore, this charger J generates a higher-level control command based on the charging time input from the charging time command device K, the outside temperature information received from the external load, the battery status signal input from the control device 10, and the charge / discharge possibility signal input from the control device h2, and outputs the higher-level control command to the control device 10.

[0022] For example, the charger J connects a pair of first input / output terminals and a pair of second input / output terminals based on the above-mentioned charging time, outside temperature information, charge / discharge enable / disable signal, and battery state signal, and outputs the battery power input to the pair of first input / output terminals due to discharge of the main battery 1 to an external load h1 of the house H for consumption.

[0023] On the other hand, the charging time command device K is electrically connected to the charger J and outputs charging times such as the charging start time and charging end time to the charger J. This charging time command device K is an operation device operated by a resident of the house H, i.e., the user of the vehicle M, and provides the information received from the user (resident) to the charger J. Such a charging time command device K corresponds to the operation unit in the present invention.

[0024] The vehicle M is an electric vehicle, hybrid vehicle, or other electrically powered vehicle that runs on electrically generated power rather than powered by an internal combustion engine. The main battery 1 is an in-vehicle battery mounted on such a vehicle M, and is a rechargeable secondary battery. The main battery 1 is, for example, a lithium-ion battery, and functions as the main power source for the vehicle M.

[0025] A pair of input / output terminals of the main battery 1 are respectively connected to a pair of first contacts of the first relay 2. The main battery 1 outputs (discharges) battery power (remaining power) from the pair of input / output terminals to the first relay 2, while charging with charging power supplied to the pair of input / output terminals from the first relay 2. The main battery 1 is additionally equipped with a heater 5, a battery charge state detection sensor 7, and a battery temperature sensor 8.

[0026] The first relay 2 has a pair of first contacts, a pair of second contacts, and a control terminal. The pair of first contacts of this first relay 2 are connected to a pair of input / output terminals of the main battery 1, and the pair of second contacts are connected to a pair of primary input / output terminals of the inverter 3, a pair of first contacts of the second relay 6, and a pair of first input / output terminals of the charger J. In addition, the control terminal of the first relay 2 is connected to a first output terminal of the relay drive circuit 9.

[0027] In the first relay 2, the connection / disconnection (close / open) of the first contact and the pair of second contacts is set based on a first relay drive signal input to the control terminal from the relay drive circuit 9. In other words, the first relay 2 connects / disconnects the inverter 3, the second relay 6, and the charger J to / from the main battery 1 based on the first relay control signal.

[0028] The inverter 3 has a pair of primary input / output terminals and three-phase secondary input / output terminals. The pair of primary input / output terminals of the inverter 3 are connected to a pair of second contacts of the first relay 2, a pair of first contacts of the second relay 6, and a pair of first input / output terminals of the charger J. Furthermore, the three secondary input / output terminals of the inverter 3 are connected to the three-phase input / output terminals of the motor 4.

[0029] The inverter 3 converts battery power (DC power) supplied from the main battery 1 via the first relay 2 into three-phase AC power (driving power) and outputs it to the motor 4. The inverter 3 also converts regenerative power (AC power) input from the motor 4 into DC power and outputs it to the first relay 2. The inverter 3 is a power converter that converts DC power and AC power mutually between a pair of primary input / output terminals and three-phase secondary input / output terminals.

[0030] The motor 4 is a three-phase motor whose three-phase input / output terminals are connected to three-phase secondary input / output terminals of the inverter 3. The motor 4 generates rotational power in its output shaft based on the driving power input from the inverter 3. The motor 4 also generates regenerative power based on the braking force acting on the output shaft and outputs it to the inverter 3.

[0031] The heater 5 is provided as an accessory to the main battery 1, and has a pair of input terminals connected to a pair of second contacts of the second relay 6. The heater 5 generates heat by operating based on operating power supplied from the main battery 1 via the first relay 2 and the second relay 6. The heat from the heater 5 heats the main battery 1.

[0032] The second relay 6 has a pair of first contacts, a pair of second contacts, and a control terminal. The pair of first contacts of this second relay 6 are connected to the pair of second contacts of the first relay 2, a pair of primary input / output terminals of the inverter 3, and a pair of first input / output terminals of the charger J. In addition, the control terminal of the first relay 2 is connected to the second output terminal of the relay drive circuit 9.

[0033] In the second relay 6, the connection / disconnection (close / open) of the first contact and the pair of second contacts is set based on a second relay drive signal input to the control terminal from the relay drive circuit 9. That is, the second relay 6 connects / disconnects the first relay 2, the inverter 3, and the charger J to / from the heater 5 based on the second relay control signal.

[0034] The battery charge state detection sensor 7 is provided incidentally to the main battery 1, and an output terminal thereof is connected to a first input terminal of the control device 10. The battery charge state detection sensor 7 detects the charge state of the main battery 1 as, for example, SOC (State Of Charge), and outputs an SOC detection signal indicating the detected amount of SOC to the first input terminal of the control device 10.

[0035] The battery temperature sensor 8 is provided as an accessory to the main battery 1, and an output terminal thereof is connected to a second input terminal of the control device 10. The battery temperature sensor 8 detects the temperature of the main battery 1 as a battery temperature T BATT The battery temperature T BATT A battery temperature detection signal indicating the detected amount is output to the second input terminal of the control device 10.

[0036] The relay drive circuit 9 has an input terminal in addition to the first and second output terminals described above. The input terminal of this relay drive circuit 9 is connected to the first output terminal of the control device 10, the first output terminal is connected to the control terminal of the first relay 2, and the second output terminal is connected to the control terminal of the second relay 6.

[0037] The relay drive circuit 9 generates a first relay drive signal and a second relay drive signal based on a relay control signal input to the input terminal from the control device 10. That is, the relay drive circuit 9 controls the operation states (open / closed states) of the first relay 2 and the second relay 6 under the control of the control device 10.

[0038] The control device 10 has three input terminals and two output terminals. The first input terminal of the control device 10 is connected to the output terminal of the battery charge state detection sensor 7, the second input terminal is connected to the output terminal of the battery temperature sensor 8, and the third input terminal is connected to the charger J. Furthermore, the first output terminal of the control device 10 is connected to the input terminal of the relay drive circuit 9, and the second output terminal is connected to the charger J.

[0039] The control device 10 generates a relay control signal and a battery state signal based on a higher-level control command input from the charger J, an SOC detection signal input from the battery charge state detection sensor 7, and a battery temperature detection signal input from the battery temperature sensor 8. The control device 10 outputs the relay control signal to an input terminal of the relay drive circuit 9 and outputs the battery state signal to a third input terminal of the charger J.

[0040] On the other hand, house H is a typical residence where the user of vehicle M resides, and is connected to a commercial power source (grid power source). Although not shown in FIG. 1, the commercial power source of house H is connected to charger J, and supplies commercial power (AC power) to charger J.

[0041] In such a house H, the external load h1 is an electrical device provided in the house H, and has a pair of input terminals and one output terminal. The pair of input terminals of the external load h1 are connected to a pair of second input / output terminals of the charger J, and the one output terminal is connected to an input terminal of the control device h2.

[0042] This external load h1 is provided in a house H, which is external to the vehicle M, and therefore corresponds to an external load from the perspective of the main battery 1 provided in the vehicle M. The external load h1 consumes battery power input from the main battery 1 via the charger J. In addition, the external load h1 outputs an operating state signal indicating its own operating state to the control device h2.

[0043] The control device h2 has an output terminal in addition to the input terminal described above. The input terminal of the control device h2 is connected to the output terminal of the external load h1, and the output terminal is connected to a fourth input terminal of the charger J. The control device h2 determines whether or not the external load h1 can consume battery power based on an operation state signal input from the external load h1, and outputs a charge / discharge enable / disable signal to the charger J indicating whether or not the external load h1 can demand the discharge power of the vehicle M.

[0044] Next, the operation of the battery charging device A according to this embodiment will be described in detail with reference to the flowchart shown in FIG.

[0045] In this battery charging device A, first, a charging time is set (step S1). That is, when a user of vehicle M returns home from an outing, the user connects a charger J connected to a commercial power source in house H to vehicle M. Then, the user operates a charging time command device K to set charging times such as a charging start time and a charging end time in charger J. For example, the user sets the charging time to a nighttime period when the electricity rate for the commercial power source is temporarily lower.

[0046] After the charging time is set in this manner, the charger J determines whether the current time corresponds to the charging time (step S2). That is, the charger J repeatedly determines at predetermined time intervals whether the current time obtained from its own timing function corresponds to the charging time specified by the charging start time and charging end time.

[0047] If the determination in step S2 is "Yes," the charger J starts charging (step S3). That is, the charger J outputs charging power generated from commercial power to the vehicle M from a pair of first input / output terminals, and generates a higher-level control command instructing the first relay 2 to be in the ON state (closed state), and outputs the command to the vehicle M from the output terminal.

[0048] The control device 10 of the vehicle M outputs a relay control signal to the relay drive circuit 9 based on the higher-level control command. The relay drive circuit 9 generates a first relay drive signal that sets the first relay 2 to the ON state (closed state) based on the relay control signal, and outputs the first relay drive signal to the first relay 2. As a result, the first relay 2 is set to the ON state (closed state), and charging power is supplied to the main battery 1 via the first relay 2.

[0049] On the other hand, if the determination in step S2 is "No," the charger J calculates the time (grace time) until charging of the main battery 1 starts (step S4). That is, the charger J calculates the grace time as the difference between the charging start time set in step S1 and the current time obtained from its own timing function.

[0050] After completing the process of step S4, the charger J acquires the SOC (State Of Charge) and battery temperature of the main battery 1 (step S5). That is, the charger J acquires the current SOC and battery temperature T BATT Get.

[0051] After completing the process of step S5, the charger J acquires a charge / discharge possibility signal input from the control device h2 (step S6). This charge / discharge possibility signal is a status signal indicating whether the external load h1 can demand the discharged power of the vehicle M, i.e., the discharged power of the main battery 1.

[0052] Then, when the process of step S6 is completed, the charger J estimates (step S7) the initial battery temperature Ts at the start of use of the vehicle M. The charger J refers to a temperature profile of the main battery 1 stored in advance based on the current battery temperature (current battery temperature) acquired in step S5, for example.

[0053] This temperature profile is temperature data that indicates the temperature change after the end of use of the main battery 1. By referring to this temperature profile, the charger J can estimate the battery temperature T BATT is estimated as the starting battery temperature Ts.

[0054] After completing the process of step S7, the charger J determines whether the starting battery temperature Ts exceeds a predetermined lower limit temperature threshold T2 (step S8). That is, the charger J compares the starting battery temperature Ts with the pre-stored lower limit temperature threshold T2 to determine whether the starting battery temperature Ts exceeds the predetermined lower limit temperature threshold T2.

[0055] If the determination in step S8 is "Yes," the charger J ends all processing, but if the determination in step S8 is "No," the charger J determines a warming schedule for the main battery 1 (step S9). That is, the charger J determines the warming schedule based on the charge / discharge availability signal acquired in step S6, the starting battery temperature Ts acquired in step S7, and the temperature profile stored in advance.

[0056] This heat retention schedule sets the main battery 1 to the optimum temperature at the start of use by heating it using the heater 5 based on the charging time input from the charging time command device K, outside temperature information received from an external device, the battery status signal input from the control device 10, and the charge / discharge possibility signal input from the control device h2.

[0057] In addition to keeping the main battery 1 warm using the heater 5, the warming schedule also heats the main battery 1 by charging and discharging the main battery 1 based on the charging time, outside temperature information, battery state signal, and charge / discharge enable / disable signal, thereby controlling the battery temperature T BATT is set to the optimum temperature.

[0058] For example, the warming schedule is to supply the remaining power of the main battery 1 to the external load h1 when the external load h1 can demand the discharged power of the main battery 1. As a result, the main battery 1 generates heat by itself and reaches the battery temperature T BATT is optimally set.

[0059] In this case, the remaining power of the main battery 1 is discharged (supplied) to the external load h1 (step S10). That is, the charger J connects the pair of first input / output terminals and the pair of second input / output terminals, and outputs a higher-level control command to the control device 10 of the vehicle M to set the first relay 2 to the ON state (closed state). As a result, the main battery 1 and the external load h1 are connected, and the remaining power of the main battery 1 is discharged (supplied) to the external load h1.

[0060] Furthermore, this warming schedule is such that when the external load h1 cannot consume the discharged power of the main battery 1, the remaining power of the main battery 1 is supplied to the heater 5 instead of being supplied to the external load h1. As a result, the main battery 1 generates heat by itself and reaches the battery temperature T BATT is optimally set.

[0061] In this case, the remaining power of the main battery 1 is discharged (supplied) to the heater 5 instead of the external load h1 (step S10). That is, the charger J separates the pair of first input / output terminals from the pair of second input / output terminals, and outputs a higher-level control command to the control device 10 of the vehicle M to set the first relay 2 and the second relay 6 to the ON state (closed state).

[0062] As a result, the main battery 1 is connected to the heater 5 via the first relay 2 and the second relay 6, and the remaining power of the main battery 1 is supplied to the heater 5. As described above, the warmth schedule in this embodiment appropriately switches the discharge destination of the remaining power for keeping the main battery 1 warm to the external load h1 or the heater 5.

[0063] Furthermore, this warming schedule causes the main battery 1 to heat up by charging the charging power in addition to discharging the remaining power of the main battery 1 to the external load h1 or the heater 5. The main battery 1 generates heat by itself due to charging the charging power, and the battery temperature T BATT is optimally set.

[0064] Here, the details of the procedure for determining the warmth schedule in step S9 will be described with reference to the flowchart in Fig. 3. The charger J requires the following three items when determining the warmth schedule. (1) The minimum allowable SOC must be exceeded at the start of use. (2) The optimum temperature is reached when you first start using it. (3) Temperature control by charging and discharging takes priority within the range that allows the optimum temperature to be reached.

[0065] That is, in step S9, the charger J first determines whether the SOC of the main battery 1 at the start of use is equal to or greater than a pre-stored minimum allowable SOC (step S9a). If the determination in step S9a is "No," the charger J charges the main battery 1 until the SOC of the main battery 1 reaches a pre-stored specified SOC (step S9b).

[0066] On the other hand, if the determination in step S9a is "Yes" or when the process in step S9b is completed, the charger J BATT If the determination in step S9a is "No", the charger J determines whether the battery temperature T BATT The heater 5 is used to heat the material until it reaches a predetermined temperature that has been stored in advance (step S9d).

[0067] On the other hand, if the determination in step S9c is "Yes" or when the processing of step S9d is completed, the charger J sets the charge / discharge time and the number of charge / discharge cycles of the main battery 1 (step S9e). That is, the charger J sets the charge / discharge time and the number of cycles by dividing the charging period into multiple sections.

[0068] After completing the process of step S9e, the charger J sets the heater temperature control to a section among the multiple sections where the battery temperature does not rise (no temperature rise section) (step S9f). That is, the charger J sets the no temperature rise section as a section where the temperature of the main battery 1 is controlled by heating the main battery 1 using the heater 5.

[0069] The charger J reflects the items set based on the processing of steps S9a to S9f above in the temperature adjustment schedule (step Sg). That is, the charger J determines the temperature adjustment schedule so as to satisfy the necessary items (1) to (3).

[0070] Figure 4 shows the battery temperature T BATT 1 is a timing chart showing an example of time-dependent changes in the battery temperature T and SOC. In this example, the battery temperature T changes before and after the charging time set by the charging start time and the charging end time. BATT and SOC.

[0071] As a result, the SOC of the main battery 1 at the departure time (start of use) of the vehicle M after the charging completion time of the main battery 1 becomes equal to or higher than the minimum allowable SOC, and the battery temperature T BATT is the optimum temperature at which the performance of the main battery 1 is maximized, that is, the temperature between the upper temperature threshold Tt and the lower temperature threshold T2.

[0072] The battery charging device A according to this embodiment includes a charger J that discharges battery power to an external load h1 to generate heat in the main battery 1. According to this embodiment, the main battery 1 generates heat without using a heater 5, making it possible to provide a battery charging device A that can maximize battery performance while effectively utilizing battery power.

[0073] The battery charging device A according to this embodiment further includes a charging time command device K (operating unit) that outputs the charging time of the main battery 1 to the charger J. The charger J monitors the battery temperature T BATT The main battery 1 is heated so that the temperature T becomes equal to or higher than a predetermined lower limit temperature threshold T2. According to this embodiment, it is possible to effectively maximize battery performance while making effective use of battery power.

[0074] Furthermore, the battery charging device A according to this embodiment further includes a heater 5 that heats the main battery 1, and the charger J switches between heat generation (heating) of the main battery 1 due to discharge to the external load h1 and heating by the heater 5. According to this embodiment, it is possible to maximize battery performance while making effective use of battery power.

[0075] Furthermore, in the battery charging device A according to this embodiment, the charger J switches between heating by discharging to the external load h1 and heating by the heater 5 based on outside air temperature information and a battery state signal (battery state). According to this embodiment, it is possible to maximize battery performance while making effective use of battery power.

[0076] Furthermore, in the battery charging device A according to this embodiment, the charger J switches between heating by discharging to the external load h1 and heating by the heater 5 before and after the charging time specified by the charging time command device K (operating unit). According to this embodiment, it is possible to maximize battery performance while making effective use of battery power.

[0077] Furthermore, in the battery charging device A according to this embodiment, the main battery 1 is an in-vehicle battery that supplies power to a motor 4 mounted on a vehicle M. According to this embodiment, it is possible to maximize the battery performance of the in-vehicle battery after charging is complete while making effective use of the battery power. [Explanation of symbols]

[0078] A Battery charging control device H house h1 External load h2 Control device J charger K Charging time controller M vehicle 1 Main battery 2. First Relay 3 inverters 4 motors 5. Heater 6. Second Relay 7 Battery charge state detection sensor 8 Battery Temperature Sensor 9 Relay drive circuit 10 Control device

Claims

1. A battery charging device comprising a charger that heats a battery by discharging battery power into an external load.

2. an operation unit that outputs a charging time of the battery to the charger; 2. The battery charging device according to claim 1, wherein the charger heats the battery so that the temperature of the battery becomes equal to or higher than a predetermined lower temperature threshold before and after the charging time.

3. Further comprising a heater for heating the battery; 3. The battery charging device according to claim 2, wherein the charger switches between heating by discharging to the external load and heating by the heater.

4. 4. The battery charging device according to claim 3, wherein the charger switches between heating by discharging to the external load and heating by the heater based on outside air temperature information and battery state.

5. 4. The battery charging device according to claim 3, wherein the charger switches between heating by discharging to the external load and heating by the heater before and after the charging time.

6. 3. The battery charging device according to claim 1, wherein the battery is an on-board battery that supplies power to a motor mounted on a vehicle.

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