Power device, display device, charging rate calculation method, program, and storage medium

Abstract

In an electric power device (10) and a charging rate calculation method according to the present invention, a control unit (30): calculates a sum total (FCC) of respective full charging capacities of a plurality of detachable / attachable batteries (16a-16d (16)); calculates a sum total (RC) of respective present charging capacities of the plurality of detachable / attachable batteries (16); and calculates an RSOC, which is an overall state of charge (SOC) of the plurality of detachable / attachable batteries (16), on the basis of the calculated sum total (FCC) of full charging capacities and the calculated sum total (RC) of present charging capacities.

Description

[Technical field]

[0001] The present invention relates to a power device having a plurality of chargeable and dischargeable power storage units, a display device that displays the overall charging rate of the plurality of power storage units, a charging rate calculation method that calculates the overall charging rate of the plurality of power storage units, a program for calculating the overall charging rate of the plurality of power storage units, and a storage medium on which the program is stored. [Background technology]

[0002] Detecting the remaining capacity of a battery (electricity storage unit) mounted on an electric vehicle (electrically-driven vehicle) in real time and displaying the detection result on a remaining capacity indicator is disclosed, for example, in Japanese Patent Application Laid-Open No. 2000-92604. Summary of the Invention

[0003] However, when multiple power storage units have different specifications, such as temperature, degree of deterioration, or type, simply calculating the average charging rate of each power storage unit may not result in the calculated average being equal to the overall charging rate of the multiple power storage units.

[0004] The present invention has been made in consideration of the above problems, and aims to provide a power device, a charging rate calculation method, a program, and a storage medium that are capable of calculating the total charging rate of a plurality of power storage units with high accuracy, and a display device that is capable of displaying the total charging rate of the plurality of power storage units thus calculated.

[0005] A first aspect of the present invention is a power device having a plurality of chargeable and dischargeable power storage units, and having a charging rate calculation unit that calculates an overall charging rate of the plurality of power storage units based on a sum of full charge capacities of each of the plurality of power storage units and a sum of current charge capacities of each of the plurality of power storage units.

[0006] A second aspect of the present invention is a display device having a receiving unit that receives the overall charging rate of the multiple power storage units from the power device, and displays the received overall charging rate of the multiple power storage units.

[0007] A third aspect of the present invention is a method for calculating a charging rate of a power device having a plurality of chargeable and dischargeable energy storage units, comprising the steps of acquiring a full charge capacity of each of the plurality of energy storage units, calculating a sum of the plurality of full charge capacities, acquiring a current charge capacity of each of the plurality of energy storage units, calculating a sum of the plurality of current charge capacities, and calculating an overall charging rate of the plurality of energy storage units based on the sum of the full charge capacities and the sum of the current charge capacities.

[0008] A fourth aspect of the present invention is a program that causes a computer to execute the steps of acquiring a full charge capacity of each of a plurality of power storage units, calculating a sum of the multiple full charge capacities, acquiring a current charge capacity of each of the plurality of power storage units, calculating the sum of the multiple current charge capacities, and calculating an overall charging rate of the plurality of power storage units based on the sum of the full charge capacities and the sum of the current charge capacities.

[0009] A fifth aspect of the present invention is a storage medium having the above-mentioned program stored therein.

[0010] According to the present invention, it is possible to accurately calculate the overall charging rate of the multiple power storage units by using the sum of the full charge capacities of the multiple power storage units and the sum of the current charge capacities of the multiple power storage units. Also, the present invention makes it possible to display the overall charging rate of the multiple power storage units thus calculated. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a configuration diagram of an embodiment of a power device according to the present embodiment. [Diagram 2] FIG. 2 is a schematic plan view of a vehicle equipped with the power device of FIG. [Diagram 3] FIG. 3 is a schematic rear view of the vehicle in FIG. 2. [Figure 4]FIG. 2 is a diagram showing a display example of the display device of FIG. [Diagram 5] FIG. 5A is a diagram showing an example of a display in a fully charged state, and FIG. 5B is a diagram showing an example of a display when the SOC has decreased. [Figure 6] FIG. 6A is a diagram showing an example of a display for battery replacement, and FIG. 6B is a diagram showing an example of a display when the cover member is opened. [Figure 7] FIG. 7A is a diagram showing an example of the display when the removable battery is removed, and FIG. 7B is a diagram showing an example of the display when the removable battery is installed. [Figure 8] 4 is a flowchart showing a first example of the operation (charging rate calculation method) of the power device according to the present embodiment. [Figure 9] 13 is a flowchart showing a second and third embodiments. [Figure 10] FIG. 10A is a diagram showing the relationship between the output voltage and the dischargeable capacity of a standard type removable battery, and FIG. 10B is a diagram showing the relationship between the output voltage and the dischargeable capacity of a high-output removable battery. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a power device, a display device, a charging rate calculation method, a program, and a storage medium according to the present invention will be described with reference to the accompanying drawings.

[0013] [1. Schematic configuration of this embodiment] Fig. 1 is a configuration diagram showing an embodiment of a power device 10 according to the present embodiment. Fig. 1 illustrates a case in which the power device 10 according to the present embodiment is applied to a power supply system 15 (power supply system) for supplying power to a drive motor 14 that is a drive source (load) of a vehicle 12.

[0014] As shown in Figs. 2 and 3, the vehicle 12 is a four-wheeled electric vehicle on which four removable batteries 16a-16d (electricity storage units) constituting the power device 10 are detachably mounted. The four removable batteries 16a-16d supply electric power to the drive motor 14 shown in Fig. 1. In the following description, the removable batteries 16a-16d may be referred to as a removable battery 16 when there is no need to distinguish between them. The removable battery 16 is charged by an external charger (not shown) when removed from the vehicle 12. That is, the removable battery 16 is a chargeable and dischargeable electricity storage device.

[0015] In this embodiment, the vehicle 12 may be any vehicle equipped with a drive motor 14, such as an electrically powered vehicle such as an electric vehicle or a hybrid vehicle. Therefore, the power device 10 according to this embodiment is not limited to four-wheeled electric vehicles, and can be applied to the power supply systems of various vehicles, such as one-wheeled, two-wheeled, and four-wheeled vehicles.

[0016] Moreover, the power device 10 is not limited to the power supply system 15 of the vehicle 12, but can be applied to various power supply systems that supply power from each removable battery 16 to a load such as the drive motor 14. Therefore, the power device 10 can be applied to power supply systems capable of supplying power to a load in various mobile objects including the vehicle 12 and aircraft, and various electronic devices.

[0017] Furthermore, the removable battery 16 may be a portable power storage device that is detachable from the power device 10, the vehicle 12, etc. Therefore, the power device 10 can employ various types of power storage devices, including a standard battery pack, a high-output battery pack, a high-capacity battery pack, and a battery for a hybrid vehicle, as the removable battery 16. The number of removable batteries 16 provided in the power device 10 may be two or more.

[0018] In the following description, as shown in Figs. 1 to 3, a case will be described in which power is supplied to a drive motor 14 from four removable batteries 16 in a power supply system 15 for a four-wheeled electric vehicle.

[0019] 2 and 3, in the vehicle 12, a driver's seat 22 is provided in the approximate center of the vehicle body 18 in the front-rear direction (the direction of the arrow A as the vehicle length direction), i.e., approximately halfway between the front wheels 20F on the side in the direction of the arrow Af (front side) and the rear wheels 20R on the side in the direction of the arrow Ab (rear side). The four removable batteries 16a to 16d (16) are disposed between the vehicle body 18 in the left-right direction (the direction of the arrow B as the vehicle width direction).

[0020] Specifically, two power storage device housings 24 capable of housing one removable battery 16 are provided side by side in the direction of arrow B in the vicinity above the rear wheel 20R on the side of the arrow B1 direction (left side) of the vehicle body 18. Furthermore, two power storage device housings 24 capable of housing one removable battery 16 are provided side by side in the direction of arrow B in the vicinity above the rear wheel 20R on the side of the arrow B2 direction (right side) of the vehicle body 18. A lid member 26 that is opened when the removable battery 16 is attached or detached is provided on the side of the arrow Ab direction (rear side) of each power storage device housing 24. The four removable batteries 16a to 16d are not limited to the arrangement shown in FIGS. 2 and 3, and can be arranged anywhere in the vehicle 12 as long as the driving operation of the driver seated in the seat 22 is not hindered.

[0021] Returning to FIG. 1, the power device 10 (power supply system 15) has a vehicle overall control unit 30 (charging rate calculation unit), DC / DC converters 32a-32d, a joint box 34, and an inverter 36. The power supply system 15 is also provided with a display device 38. Furthermore, each of the removable batteries 16a-16d has a battery management unit 40a-40d (hereinafter referred to as BMU 40a-40d). In the following description, the vehicle overall control unit 30 may be referred to as a control unit 30. Furthermore, when the DC / DC converters 32a-32d are not particularly distinguished, they may be referred to as a DC / DC converter 32. Furthermore, the multiple BMUs 40a-40d may also be referred to as a BMU 40 when they are not particularly distinguished.

[0022] The control unit 30 has a communication section (transmitter) 30a. The display device 38 has a communication section (receiver) 38a. Each of the communication sections 30a, 38a is connected to a CAN 42 for communicating with each device in the vehicle 12, and a CAN 44 for communicating with each device related to the removable batteries 16a-16d, respectively. The DC / DC converters 32a-32d and the BMUs 40a-40d of the removable batteries 16a-16d are connected to the CAN 44.

[0023] The control unit 30 is a computer (information processing device) serving as an ECU (electronic control unit) mounted on the vehicle 12, and realizes various functions including calculation of a charging rate, which will be described later, by reading and executing a program stored in a storage unit 30b, which is a non-transient storage medium. That is, the control unit 30 acquires an ignition signal, which is an ON signal, from an ignition switch 46, which is a drive switch of the vehicle 12. The control unit 30 also acquires accelerator pedal opening information from an accelerator pedal sensor 48. In this case, the control unit 30 sets the torque of the drive motor 14 according to the accelerator pedal opening information, and outputs the torque command value from the communication unit 30a to the CAN 42. The control unit 30 also sets a current command value, which is a PWM signal for converting the output voltage of the removable battery 16, according to the torque command value, and outputs the set current command value from the communication unit 30a to the CAN 44.

[0024] The control unit 30 also acquires a lid opening / closing signal indicating the detection result of opening / closing of the lid member 26 from the lid switch 50. The control unit 30 sets the display content of the display device 38 according to the open or closed state of the lid member 26 indicated by the lid opening / closing signal, and outputs a display instruction signal indicating the set display content from the communication unit 30a to the CAN 44.

[0025] Furthermore, when the communication unit 30a acquires (receives) information on each of the removable batteries 16a-16d from each of the BMUs 40a-40d via the CAN 44, the control unit 30 ascertains the SOC (hereinafter, may be referred to as the charging rate or the charging capacity) of each of the removable batteries 16a-16d based on the acquired information. Then, when any of the removable batteries 16a-16d has an SOC below a predetermined value, the control unit 30 sets display content to notify the replacement of the removable battery 16a-16d, and outputs a display instruction signal indicating the set display content from the communication unit 30a to the CAN 44.

[0026] Furthermore, the control unit 30 determines, from the information of each of the removable batteries 16a-16d acquired by the communication section 30a, whether or not each of the removable batteries 16a-16d is loaded in the power storage device accommodation section 24, i.e., whether or not the removable batteries 16a-16d are electrically connected to the DC / DC converters 32a-32d. The control unit 30 sets display content according to the determination result, and outputs a display instruction signal indicating the set display content from the communication section 30a to the CAN 44.

[0027] Furthermore, the control unit 30 calculates the total SOC of the removable batteries 16a-16d (the SOC (charging rate) of a single power storage device when the removable batteries 16a-16d are regarded as a single power storage device) from the information of each of the removable batteries 16a-16d acquired by the communication section 30a. The control unit 30 sets the display content of the calculated total SOC of the removable batteries 16a-16d, and outputs a display instruction signal indicating the set display content from the communication section 30a to the CAN 44.

[0028] The BMUs 40a-40d manage the SOC, temperature (temperature coefficient), deterioration level (degree of deterioration, deterioration coefficient), internal resistance, and current charge capacity as remaining capacity of the removable batteries 16a-16d, and the connection state between the removable batteries 16a-16d and the DC / DC converters 32a-32d. The BMUs 40a-40d also manage the specifications (specification difference values ​​such as specification coefficients), specification values ​​or initial values ​​of full charge capacity, and current full charge capacity of the removable batteries 16a-16d. The BMUs 40a-40d output this information to the CAN 44.

[0029] Therefore, the control unit 30 acquires the current charge capacity, current full charge capacity, and specification value or initial value of the full charge capacity of each of the removable batteries 16a-16d from the BMUs 40a-40d. The specification value of the full charge capacity refers to the standard value of the full charge capacity of the removable batteries 16a-16d. Also, the initial value of the full charge capacity refers to the value of the full charge capacity (initial full charge amount) when the removable batteries 16a-16d start to be used (at the time of shipment from the factory).

[0030] The DC / DC converter 32 converts the output voltage of the removable battery 16 in accordance with the current command value, and outputs the converted output voltage to the joint box 34. The joint box 34 supplies DC power from the removable battery 16 to the inverter 36. The inverter 36 converts the DC power supplied from the joint box 34 into three-phase AC power in accordance with the torque command value, and supplies it to the drive motor 14. The inverter 36 also outputs rotation speed information and actual torque information of the drive motor 14 to the CAN 42.

[0031] The display device 38 is composed of a screen 62 (see FIG. 4) set on the dashboard or the like of the vehicle 12, and a processing device that processes characters and images to be displayed on the screen 62. Information from the inverter 36 or the drive motor 14 is input (received) to the display device 38 via a communication unit 38a, and SOC information (information on various charging rates or charge capacities) of the removable battery 16 and a display instruction signal from the control unit 30 are input (received) from the CAN 44 via the communication unit 38a. The display device 38 displays the status of the removable battery 16 based on the various information input to the communication unit 38a.

[0032] [2. Display Contents on Display Device 38] 4 is a diagram showing an example of display on the display device 38. The display device 38 has battery remaining capacity display units 52a-52d, a total remaining capacity display unit 54, open / close state display units 56a-56d, battery replacement display units 58a-58d, and battery connection state display units 60a-60d.

[0033] Each of the battery remaining capacity display units 52a-52d is provided on the right side of the screen 62 of the display device 38. Of these, the two battery remaining capacity display units 52a, 52b on the right side correspond to the two removable batteries 16a, 16b arranged on the right side of the vehicle body 18 (see FIGS. 2 and 3). Moreover, the two battery remaining capacity display units 52c, 52d on the left side correspond to the two removable batteries 16c, 16d arranged on the left side of the vehicle body 18.

[0034] Each battery remaining capacity display section 52a-52d displays the number of each removable battery 16a-16d, a picture of a dry cell with a bar graph inside, and the SOC value of each removable battery 16a-16d. The bar graph inside the dry cell changes vertically according to the SOC of the corresponding removable battery 16a-16d.

[0035] In Fig. 4, ten rectangular segments are arranged vertically inside the picture of a dry cell. Each segment is, for example, an LED, and when one segment is lit, it indicates 10% of the SOC. In Figs. 4 to 7B, the lit state is shown by hatching, and the unlit state is shown by white. Therefore, each battery remaining capacity display unit 52a to 52d roughly indicates the magnitude of the SOC by lighting up in order from the lower segment to the upper segment according to the magnitude of the SOC of the corresponding removable battery 16a to 16d.

[0036] In FIG. 4, none of the segments are lit, indicating that the SOC of each of the removable batteries 16a-16d is 0%. In FIG. 5A, all of the segments for one removable battery 16a are lit, indicating that the SOC of the removable battery 16a is 100%. In FIG. 5B, the bottom three segments are lit, indicating that the SOC of the removable battery 16a is 30%. In FIG. 6A, one bottom segment is lit, indicating that the SOC of the removable battery 16a is 10%.

[0037] In this case, the lighting color of the segments may be changed according to the magnitude of the SOC. In Figures 5B and 6A, the hatching direction within the segments is changed compared to Figure 5A, to show that the segments are lit in different colors.

[0038] Around the picture imitating a dry cell of each battery remaining capacity display section 52a-52d, there are arranged open / closed state display sections 56a-56d, battery replacement display sections 58a-58d, and battery connection state display sections 60a-60d. These display sections are provided around the battery remaining capacity display sections 52a-52d of the corresponding removable batteries 16a-16d.

[0039] When turned on, the open / closed state display units 56a-56d indicate that the lid member 26 of the power storage device housing unit 24 housing the corresponding removable battery 16a-16d is open, and when turned off, they indicate that the lid member 26 is closed. In Figures 4-7B, the lit state is shown by a solid line, and the unlit state is shown by a dashed line.

[0040] When the battery replacement indicators 58a-58d are lit, they indicate that the corresponding removable batteries 16a-16d need to be replaced, and when they are turned off, they indicate that such replacement is not necessary. In Figures 4-7B, the lit state is shown by a solid line, and the turned off state is shown by a dashed line.

[0041] When the battery connection status display units 60a-60d are lit, they indicate that the corresponding removable batteries 16a-16d are loaded into the power storage device housing 24 and that the removable batteries 16a-16d are electrically connected to the DC / DC converters 32a-32d. When the battery connection status display units 60a-60d are turned off, they indicate that the removable batteries 16a-16d are not loaded into the power storage device housing 24 or that, even if loaded, the removable batteries 16a-16d are not electrically connected to the DC / DC converters 32a-32d. In Figs. 4-7B, the lit states are shown by filled circles, and the turned off states are shown by hollow circles.

[0042] The total remaining capacity display unit 54 displays the overall SOC of the four removable batteries 16a-16d. The total remaining capacity display unit 54 is made up of ten segments arranged horizontally. Each segment is, for example, an LED, and lighting one segment displays 10% of the SOC. Therefore, the total remaining capacity display unit 54 displays the approximate magnitude of the SOC by lighting the segments in sequence from the left side (E side indicating 0% SOC) to the right side (F side indicating 100% SOC) according to the magnitude of the overall SOC of each of the removable batteries 16a-16d.

[0043] 5A to 7B show the change in the display content of the display device 38 before and after battery replacement for one removable battery 16a. Note that the display content of the display device 38 also changes in the same way when the other removable batteries 16b to 16d are replaced.

[0044] Fig. 5A shows a state in which the removable battery 16a is accommodated in the power storage device accommodation section 24 (see Figs. 2 and 3), the cover member 26 is closed, and the SOC of the removable battery 16a is 100%. In this case, all segments of the battery remaining capacity display section 52a are lit, and the word "100%" indicating the numerical value of the SOC is displayed. In addition, the battery connection status display section 60a is lit, and the open / close status display section 56a and the battery replacement display section 58a are turned off.

[0045] Fig. 5B shows a case where the SOC of the removable battery 16a has dropped to 30%. In this case, the three lower segments of the battery remaining capacity display section 52a are lit, and the text "30%" indicating the numerical value of the SOC is displayed. Because the SOC has dropped, the three lower segments are lit in a different color than in Fig. 5A.

[0046] 6A shows a case where the SOC of the removable battery 16a has dropped to 10%. In this case, the battery remaining capacity display unit 52a has one lower segment lit and displays the character "10%" indicating the numerical value of the SOC. In addition, the battery replacement display unit 58a is lit, urging the driver or the like to replace the removable battery 16a.

[0047] When the driver or the like opens the lid member 26 (see FIGS. 2 and 3) of the power storage device housing section 24 that houses the removable battery 16a while looking at the screen display in Fig. 6A, the screen 62 of the display device 38 switches to the display content in Fig. 6B. In Fig. 6B, the open / closed state display section 56a lights up to notify that the lid member 26 is open.

[0048] When the driver or the like removes the removable battery 16a from the power storage device housing section 24, the screen 62 of the display device 38 switches to the display contents shown in Fig. 7A. In Fig. 7A, the battery connection status display section 60a is turned off, and the open / close status display section 56a and the battery replacement display section 58a are turned on. Additionally, the battery remaining capacity display section 52a turns off all segments and displays the character string "0%" which indicates the SOC value.

[0049] Next, when the driver or the like loads a fully charged removable battery 16a into the power storage device housing section 24, the screen 62 of the display device 38 switches to the display contents shown in Fig. 7B. In Fig. 7B, the battery connection status display section 60a, the open / close status display section 56a, and the battery replacement display section 58a are all lit. Additionally, the battery remaining capacity display section 52a lights up all segments and displays the characters "100%" which indicate the SOC value.

[0050] Next, when the driver or the like closes the cover member 26, the screen 62 of the display device 38 switches to the display content of Fig. 5A, whereby the open / closed state display section 56a and the battery replacement display section 58a are turned off.

[0051] [3. SOC calculation process] Next, a characteristic function of the power device 10 according to this embodiment will be described with reference to Fig. 8 to Fig. 10B. The characteristic function is to accurately calculate the overall SOC of the multiple removable batteries 16 even when multiple removable batteries 16 of different types are housed in the power storage device housing 24. This characteristic function is also applicable to the calculation process of the SOC for multiple removable batteries 16 of the same type.

[0052] Here, three methods (a first embodiment in FIG. 8, a second embodiment in FIG. 9, and a third embodiment in FIG. 9) relating to the calculation process of the SOC using the characteristic functions will be described in order.

[0053] <3.1 First Example> In the first embodiment of Fig. 8, the control unit 30 (see Fig. 1) calculates the overall SOC of the multiple removable batteries 16 by considering the temperature coefficient, deterioration coefficient, and specification coefficient (specification difference value) of each of the four removable batteries 16. Therefore, the first embodiment is applicable to both four removable batteries 16 of the same type and four removable batteries 16 of different types.

[0054] The types of removable batteries 16 include, for example, differences in capacity or output, and differences in battery structure. In this embodiment, removable batteries 16 of the same structure are treated as different types of removable batteries 16 if they are a standard type, a high-output type, or a high-capacity type. In addition, general battery packs and hybrid vehicle batteries are also treated as different types of removable batteries 16.

[0055] First, in step S1, when the driver turns on the ignition switch 46, an ignition signal is supplied from the ignition switch 46 to the control unit 30. This causes the power supply system 15 (power device 10) in the vehicle 12 to start up.

[0056] In the next step S2, the communication unit 30a of the control unit 30 acquires information on each removable battery 16 from each BMU 40 via the CAN 44. The acquired information includes the SOC of each removable battery 16, a state indicating whether each removable battery 16 is loaded in each power storage device accommodation section 24, and the like. Note that the SOC information acquired by the communication unit 30a in step S2 includes the current charge capacity, current full charge capacity, and specification value or initial value of the full charge capacity of each removable battery 16.

[0057] In the next step S3, the control unit 30 determines, based on the information of each removable battery 16 acquired by the communication unit 30a, whether or not a removable battery 16 is accommodated in each power storage device accommodation unit 24. The control unit 30 also determines whether or not the SOC of each removable battery 16 is not 0%.

[0058] In step S3, if removable batteries 16 are accommodated in all of the power storage device accommodation sections 24 and there is no removable battery 16 with an SOC of 0% (step S3: YES), the control unit 30 proceeds to the process of step S4.

[0059] In step S4, the control unit 30 confirms the type of each removable battery 16 based on the information of each removable battery 16 acquired in step S2.

[0060] In step S5, the communication section 30a of the control unit 30 acquires the temperature coefficient, deterioration coefficient, and specification coefficient of each removable battery 16 from each BMU 40 via the CAN 44. The specification coefficient is a coefficient related to the specification difference of the removable battery 16 with respect to an arbitrary removable battery 16 that is set as a reference battery. Therefore, the specification coefficient is a type of specification difference value. For example, if the capacity of the reference removable battery 16 is 1000Wh, the specification coefficient of a removable battery 16 with a capacity of 500Wh is 0.5 (500 / 1000=0.5). Also, the specification coefficient of a removable battery 16 with a capacity of 2000Wh is 2.0 (2000 / 1000=2.0).

[0061] In step S6, the control unit 30 calculates the total FCC of the full charge capacity of each removable battery 16 based on the information of each removable battery 16 acquired by the communication unit 30a from each BMU 40 via the CAN 44. In this case, if each removable battery 16 is not deteriorated, the total FCC of each full charge capacity is the total FCC0 of the specification value or initial value of the full charge capacity of each removable battery 16. Also, if each removable battery 16 is deteriorated, the total FCC of each full charge capacity is the sum of each full charge capacity at the current time. That is, the total FCC of each full charge capacity is expressed by the following formula (1). Note that Σ is a mathematical symbol indicating a sum. FCC = Σ(full charge capacity of each removable battery 16) (1)

[0062] In step S7, the control unit 30 calculates the total RC of the current remaining capacity (current charge capacity) of each removable battery 16 based on the information of each removable battery 16 acquired by the communication unit 30a from each BMU 40 via the CAN 44. In this case, the control unit 30 calculates based on the full charge capacity and the current SOC of each removable battery 16. Alternatively, the control unit 30 may calculate the total RC of the current charge capacity based on the SOC, temperature coefficient, deterioration coefficient, and specification coefficient of each removable battery 16. Furthermore, the control unit 30 may calculate the total RC of the current charge capacity based on the time integrated value of the current (charging current, discharging current) that charges and discharges each removable battery 16.

[0063] Therefore, the total current charge capacity RC is expressed by any one of the following equations (2) to (4). RC = Σ{(SOC of each removable battery 16) × (temperature coefficient) × (deterioration coefficient) × (specification coefficient)} (2) RC = Σ{(full charge capacity of each removable battery 16) × (SOC of each removable battery 16)} (3) RC = Σ (integrated value of current for charging and discharging each removable battery 16) (4)

[0064] In step S8, the control unit 30 calculates RSOC, which is the overall SOC of each removable battery 16, by dividing the sum RC of the current charge capacities of each removable battery 16 by the sum FCC of the full charge capacities of each removable battery 16. In this case, RSOC is expressed by the following equation (5). RSOC=RC / FCC (5)

[0065] In step S9, the control unit 30 controls each BMU 40 and each DC / DC converter 32 based on the calculated RSOC and the like.

[0066] In this case, the control unit 30 assigns an ID to each BMU 40 (each removable battery 16) when transmitting and receiving information via the CAN 44, and outputs the assigned ID from the communication unit 30a to the CAN 44. The control unit 30 also outputs a control command for controlling the BMU 40 to which the ID has been assigned, based on the RSOC or the like, from the communication unit 30a to the CAN 44. As a result, the BMU 40 causes a current to flow from the removable battery 16 to the DC / DC converter 32, based on the control command acquired from the CAN 44.

[0067] Furthermore, the control unit 30 adjusts the current command value for each DC / DC converter 32 taking into consideration the RSOC, and outputs each adjusted current command value from the communication unit 30a to the CAN 44. The DC / DC converter 32 converts the output voltage of the removable battery 16 based on the current command value acquired from the CAN 44.

[0068] In step S10, the control unit 30 sets the display content of the display device 38 according to the calculated RSOC, etc., as a display instruction signal, and outputs the set display instruction signal from the communication unit 30a to the CAN 44. As a result, the display device 38 performs screen display of Figs. 5A to 7B, etc., based on the display instruction signal, etc. acquired by the communication unit 38a via the CAN 44.

[0069] In step S11, when the processes of steps S2 to S11 are to be repeatedly executed (step S11: YES), the control unit 30 returns to step S2. After the driver checks the display contents of the display device 38 in step S10, the driver can move the vehicle 12 by operating the vehicle 12 in step S12. In this case, after step S12, the determination process of step S11 is executed.

[0070] <3.2 Second Example> The second embodiment relates to a process for calculating the overall SOC of each removable battery 16 when there is a power storage device accommodation section 24 that does not accommodate a removable battery 16, or when there is a removable battery 16 with an SOC of 0% even if each power storage device accommodation section 24 accommodates a removable battery 16.

[0071] In this case, the number of removable batteries 16 supplying power is reduced, so that the load per removable battery 16 increases and the overall output of the multiple removable batteries 16 decreases. As a result, the overall capacity of the multiple removable batteries 16 decreases instead. This will be specifically described with reference to Figures 10A and 10B.

[0072] 10A is a diagram showing the relationship between the voltage of a standard type removable battery 16 and the total dischargeable capacity of multiple removable batteries 16. The solid line shows the results when four removable batteries 16 are mounted on the vehicle 12. When four fully charged removable batteries 16 are mounted on the vehicle 12, the total dischargeable capacity of the four removable batteries 16 is 100%. Furthermore, in the case of four removable batteries 16, discharging is at 1C.

[0073] 10A, the dashed line indicates the case where two removable batteries 16 are mounted on the vehicle 12. In the case of the dashed line, when two fully charged removable batteries 16 are mounted on the vehicle 12, the total dischargeable capacity of the two removable batteries 16 drops to 95% compared to the total dischargeable capacity (100%) of four removable batteries 16. Also, compared to the case of four removable batteries 16, the load per battery increases with two removable batteries 16, resulting in a high discharge rate of 2C discharge. For example, when four removable batteries 16 (solid lines) and two removable batteries 16 (dashed lines) are used to produce the same output (10 kW), the closed circuit voltage for four removable batteries 16 will be 50 V and the discharge current will be approximately 160 A (40 A per battery), whereas the closed circuit voltage for two removable batteries 16 will drop to 45 V and the discharge current will increase to 200 A (100 A per battery).

[0074] Fig. 10B is a diagram showing the relationship between the voltage of a high-output type removable battery 16 and the total dischargeable capacity of multiple removable batteries 16. The solid line shows the case where four removable batteries 16 are mounted on the vehicle 12. In Fig. 10B as well, when four fully charged removable batteries 16 are mounted on the vehicle 12, the total dischargeable capacity of the four removable batteries 16 is 100%. Furthermore, the four removable batteries 16 are discharged at 1C.

[0075] Also, in FIG. 10B, the dashed line indicates the case where two removable batteries 16 are mounted on the vehicle 12. In the case of the high-output type, in the case of the dashed line, when two fully charged removable batteries 16 are mounted on the vehicle 12, the total dischargeable capacity of the two removable batteries 16 drops to 98% compared to the total dischargeable capacity (100%) of four removable batteries 16. Therefore, also in FIG. 10B, compared to the case of four removable batteries 16, the load per battery 16 increases with two removable batteries 16, resulting in a 2C discharge. However, compared to the result of the standard type removable battery 16 (dashed line in FIG. 10A), the drop in dischargeable capacity is suppressed to 2% in the result of the dashed line in FIG. 10B.

[0076] In the second embodiment, the overall SOC of each removable battery 16 is calculated taking into consideration the increased load on the removable batteries 16 due to the reduction in the number of batteries. In the following explanation of the second embodiment, a case will be described in which two removable batteries 16 of the same type are mounted on the vehicle 12.

[0077] Specifically, in step S2 of FIG. 8, if the four removable batteries 16 are not accommodated in the power storage device accommodation section 24, or the SOC of at least one of the removable batteries 16 is 0% (step S2: NO), the control unit 30 proceeds to step S21 of FIG. 9.

[0078] In step S21, the control unit 30 confirms the number of removable batteries 16 mounted on the vehicle 12 and the type of each removable battery 16 based on the information of each removable battery 16 acquired by the communication section 30a.

[0079] In step S22, the communication section 30a of the control unit 30 acquires the temperature coefficient, deterioration coefficient, and specification coefficient of each removable battery 16 from each BMU 40 via the CAN 44, similarly to step S4. Note that if a removable battery 16 is not housed in the power storage device housing section 24, the above information cannot be acquired. Also, even if a removable battery 16 is housed in the power storage device housing section 24, if the SOC is 0%, the communication section 30a of the control unit 30 acquires information including the fact that the SOC is 0%.

[0080] In step S23, similar to step S6, the control unit 30 calculates the total FCC of the full charge capacities of the removable batteries 16. In this case, the control unit 30 calculates the total FCC of the full charge capacities of the two removable batteries 16.

[0081] In step S24, the control unit 30 calculates the sum RC0 of the current charge capacities of the two housed removable batteries 16. Next, the control unit 30 determines a correction coefficient according to the number and type of removable batteries 16 mounted on the vehicle 12.

[0082] Here, the correction coefficient is a numerical value corresponding to the decrease in dischargeable capacity caused by, for example, a decrease in the number of removable batteries 16 mounted on the vehicle 12 from four to two. Specifically, in the case of the standard type removable battery 16 in Fig. 10A, the correction coefficient is 0.95, which corresponds to a 5% decrease. Also, in the case of the high-power type removable battery 16 in Fig. 10B, the correction coefficient is 0.98, which corresponds to a 2% decrease.

[0083] In step S25, the control unit 30 takes into account the correction coefficient to calculate the total RC of the current charge capacities of the removable batteries 16. That is, the control unit 30 calculates the total RC using the following equation (6). RC = RC0 × (correction coefficient) (6)

[0084] Then, in step S8 in FIG. 8 after step S25, the control unit 30 calculates RSOC from equation (5) using the total current charge capacity RC calculated from equation (6) and the total full charge capacity FCC.

[0085] <3.3 Third Example> The third embodiment differs from the second embodiment in that even when the number of removable batteries 16 installed in the vehicle 12 is small, the sum of the full charge capacities of the four removable batteries 16 is used as the total full charge capacity FCC, while the remaining capacity of the number of installed removable batteries 16 is used as the total current charge capacity RC.

[0086] In this case, in step S23, the control unit 30 calculates the total FCC of the full charge capacities of the four removable batteries 16, similarly to step S6.

[0087] After step S23, the control unit 30 proceeds to step S31, where it calculates the total RC of the current charge capacities, taking into consideration the number of removable batteries 16 that are not mounted on the vehicle 12. That is, the control unit 30 calculates the sum of the current charge capacities of the two removable batteries 16 mounted on the vehicle 12 as the total RC.

[0088] Then, in step S8 of FIG. 8 after step S31, the control unit 30 calculates RSOC from equation (5) using the total full charge capacity FCC calculated in step S23 and the total current charge capacity RC calculated in step S31.

[0089] <3.4 Modifications of each embodiment> In the above embodiments, the total FCC of the full charge capacity is calculated, and then the total RC of the current charge capacity is calculated (steps S6→S7, S23→S25, S31). In the present embodiment, the total RC of the current charge capacity is calculated first, and then the total FCC of the full charge capacity is calculated (steps S7→S6, S25, S31→S23).

[0090] In each of the above examples, the control unit 30 acquires the full charge capacity and the current charge capacity in step S2. In the present embodiment, the control unit 30 may acquire the current charge capacity and the full charge capacity in step S5 or S22. Alternatively, the control unit 30 may acquire either the full charge capacity or the current charge capacity in step S2, and acquire the other in step S5 or S22.

[0091] In addition, in this embodiment, the control unit 30 can perform processing such that after acquiring either the full charge capacity or the current charge capacity, it calculates the sum of the acquired one of the charge capacities, and then acquires the other charge capacity and calculates the sum of the other acquired charge capacity.

[0092] Thus, in this embodiment, it should be noted that the processing order in the control unit 30 is not limited to the order described in the first to third embodiments.

[0093] [4. Effects of this embodiment] As described above, this embodiment is a power device 10 having a plurality of chargeable and dischargeable removable batteries 16a-16d (16) (power storage unit), and a control unit 30 (charging rate calculation unit) calculates RSOC, which is the overall SOC (charging rate) of the plurality of removable batteries 16a-16d, based on the sum FCC of the full charge capacities of each of the plurality of removable batteries 16a-16d and the sum RC of the current charge capacities of each of the plurality of removable batteries 16a-16d.

[0094] Moreover, this embodiment is a display device 38, which has a communication unit 38a (receiving unit) that receives the total SOC (RSOC) of the multiple removable batteries 16a to 16d from the power device 10, and displays the received RSOC.

[0095] Furthermore, the present embodiment is a method for calculating a charging rate of a power device 10 having a plurality of chargeable and dischargeable removable batteries 16a to 16d (16), and includes a step of acquiring a full charge capacity of each of the plurality of removable batteries 16a to 16d (step S2), a step of calculating a total FCC of the plurality of full charge capacities (steps S6, S23), a step of acquiring a current charge capacity of each of the plurality of removable batteries 16a to 16d (step S2), a step of calculating a total RC of the plurality of current charge capacities (steps S7, S25, S31), and a step of calculating an RSOC based on the total FCC of the full charge capacities and the total RC of the current charge capacities (step S8).

[0096] Furthermore, the present embodiment is a program that causes a control unit 30 of the power device 10 as a computer to execute the following steps: acquiring a full charge capacity of each of the multiple removable batteries 16a-16d (step S2); calculating a total FCC of the multiple full charge capacities (steps S6, S23); acquiring a current charge capacity of each of the multiple removable batteries 16a-16d (step S2); calculating a total RC of the multiple current charge capacities (steps S7, S25, S31); and calculating an RSOC based on the total FCC of the full charge capacities and the total RC of the current charge capacities (step S8).

[0097] In this embodiment, the storage unit 30b (storage medium) stores the above-mentioned program.

[0098] In this way, by using the sum FCC of the respective fully charged capacities of the removable batteries 16a-16d and the sum RC of the respective current charged capacities of the removable batteries 16a-16d, it is possible to accurately calculate RSOC, which is the overall SOC of the removable batteries 16a-16d, and to display the RSOC thus calculated.

[0099] In this case, the full charge capacity is found based on the specification values ​​or initial values ​​relating to the full charge capacity of the removable batteries 16a to 16d, which allows the RSOC to be calculated with even greater accuracy.

[0100] Furthermore, the full charge capacity is found based on at least one of the temperature and the degree of deterioration of the removable batteries 16a to 16d, which allows the RSOC to be calculated with even greater accuracy based on the current state of each of the removable batteries 16a to 16d.

[0101] Furthermore, when there is a specification difference among the multiple removable batteries 16a-16d, the full charge capacity is calculated based on a specification difference value (e.g., a specification coefficient, etc.) that is set according to the specification difference. This makes it possible to accurately calculate the RSOC by taking into account the specification difference among the removable batteries 16a-16d.

[0102] Furthermore, the current charge capacity is calculated based on the integrated value of the current that charges and discharges the removable batteries 16a to 16d, thereby making it possible to accurately calculate RSOC.

[0103] In addition, the control unit 30 can calculate RSOC by dividing the total current charge capacity RC by the total full charge capacity FCC, which makes it possible to easily calculate RSOC.

[0104] Furthermore, the control unit 30 corrects the total current charge capacity RC according to the number and type of the multiple removable batteries 16a-16d as in the second embodiment, making it possible to calculate an optimal RSOC taking into account the decrease in discharge capacity due to a decrease in the number of removable batteries 16a-16d.

[0105] Furthermore, as in the third embodiment, the control unit 30 corrects the total current charge capacity RC according to the number of removable batteries 16a-16d whose current charge capacity is 0. Even in this case, it is possible to calculate an optimal RSOC by taking into consideration the decrease in discharge capacity due to a decrease in the number of removable batteries 16a-16d.

[0106] Furthermore, the multiple removable batteries 16a-16d are power storage devices that are detachable from the vehicle 12, and the control unit 30 is a control device mounted on the vehicle 12. This allows the power device 10 to be suitably applied as the power supply system 15 of the vehicle 12.

[0107] Moreover, the power device 10 further includes a communication unit 30a (transmission unit) that transmits the RSOC calculated by the control unit 30 to the display device 38. This allows the display device 38 to receive the RSOC via the communication unit 38a and reliably display the received RSOC.

[0108] It should be noted that the present invention is not limited to the above-described embodiment, and various configurations can be adopted based on the contents of this specification.

Claims

1. A power device (10) having a plurality of chargeable and dischargeable power storage units (16, 16a to 16d), a charging rate calculation unit (30) that calculates an overall charging rate (RSOC) of the plurality of power storage units based on a sum of full charge capacities (FCC) of the respective plurality of power storage units and a sum of current charge capacities (RC) of the respective plurality of power storage units, The power device, wherein, when there is a specification difference between the plurality of power storage units, the full charge capacity is calculated based on a specification difference value that is set in accordance with the specification difference.

2. An electric power device (10) having a plurality of chargeable and dischargeable electric storage units (16, 16a to 16d), a charging rate calculation unit (30) that calculates an overall charging rate (RSOC) of the plurality of power storage units based on a sum of full charge capacities (FCC) of the respective plurality of power storage units and a sum of current charge capacities (RC) of the respective plurality of power storage units, The power device, wherein the charging rate calculation unit corrects the sum of the current charging capacities depending on the number and type of the plurality of power storage units.

3. An electric power device (10) having a plurality of chargeable and dischargeable power storage units (16, 16a to 16d), a charging rate calculation unit (30) that calculates an overall charging rate (RSOC) of the plurality of power storage units based on a sum of full charge capacities (FCC) of the respective plurality of power storage units and a sum of current charge capacities (RC) of the respective plurality of power storage units, The power device, wherein the charging rate calculation unit corrects the sum of the current charging capacities in accordance with the number of the power storage units whose current charging capacities are zero.

4. In the power device according to claim 2 or 3, The power device, wherein, when there is a specification difference between the plurality of power storage units, the full charge capacity is calculated based on a specification difference value that is set in accordance with the specification difference.

5. In the power device according to any one of claims 1 to 4, The full charge capacity is calculated based on a specification value or an initial value relating to the full charge capacity of the power storage unit.

6. In the power device according to any one of claims 1 to 5, The full charge capacity is calculated based on at least one of a temperature and a deterioration degree of the power storage unit.

7. In the power device according to any one of claims 1 to 6, The present charge capacity is calculated based on an integrated value of a current that charges and discharges the power storage unit.

8. In the power device according to any one of claims 1 to 7, The power device, wherein the charging rate calculation unit calculates the overall charging rate of the plurality of power storage units by dividing the sum of the current charging capacities by the sum of the full charging capacities.

9. In the electric power device according to claim 1, claim 3, or any one of claims 4 to 8 dependent on claim 1 or 3, The power device, wherein the charging rate calculation unit corrects the sum of the current charging capacities depending on the number and type of the plurality of power storage units.

10. In the electric power device according to claim 1, claim 2, or any one of claims 4 to 8 dependent on claim 1 or 2, The power device, wherein the charging rate calculation unit corrects the sum of the current charging capacities in accordance with the number of the power storage units whose current charging capacities are zero.

11. In the power device according to any one of claims 1 to 10, The plurality of power storage units are power storage devices that are detachable from the vehicle (12), The charging rate calculation unit is a control device mounted on the vehicle.

12. In the power device according to any one of claims 1 to 11, The power device further comprises a transmission unit (30a) that transmits the total charging rate of the plurality of power storage units calculated by the charging rate calculation unit to a display device (38).

13. A display device (38) having a receiving unit (38a) that receives the total charging rate of the plurality of power storage units from the power device according to any one of claims 1 to 12, and displays the received total charging rate of the plurality of power storage units.

14. A method for calculating a charging rate of a power device (10) having a plurality of chargeable and dischargeable power storage units (16, 16a to 16d), comprising the steps of: acquiring a full charge capacity of each of the plurality of power storage units; Calculating a sum of the full charge capacities (FCC); acquiring a current charge capacity of each of the plurality of power storage units; Calculating a sum (RC) of the plurality of current charge capacities; calculating a total state of charge (RSOC) of the plurality of power storage units based on the sum of the full charge capacities and the sum of the current charge capacities; having The charging rate calculation method, wherein, when there is a specification difference between the plurality of power storage units, the full charge capacity is calculated based on a specification difference value that is set in accordance with the specification difference.

15. A method for calculating a charging rate of an electric power device (10) having a plurality of chargeable and dischargeable power storage units (16, 16a to 16d), comprising the steps of: acquiring a full charge capacity of each of the plurality of power storage units; Calculating a sum of the full charge capacities (FCC); acquiring a current charge capacity of each of the plurality of power storage units; Calculating a sum (RC) of the plurality of current charge capacities; calculating a total state of charge (RSOC) of the plurality of power storage units based on the sum of the full charge capacities and the sum of the current charge capacities; having The charging rate calculation method, in the step of calculating the charging rate, the sum of the current charge capacities is corrected depending on the number and type of the plurality of power storage units.

16. A method for calculating a charging rate of an electric power device (10) having a plurality of chargeable and dischargeable power storage units (16, 16a to 16d), comprising the steps of: acquiring a full charge capacity of each of the plurality of power storage units; Calculating a sum of the full charge capacities (FCC); acquiring a current charge capacity of each of the plurality of power storage units; Calculating a sum (RC) of the plurality of current charge capacities; calculating a total state of charge (RSOC) of the plurality of power storage units based on the sum of the full charge capacities and the sum of the current charge capacities; having A charging rate calculation method, wherein in the step of calculating the charging rate, the total of the current charging capacities is corrected depending on the number of the power storage units whose current charging capacities are zero.

17. A program that causes a computer (30) to execute the charging rate calculation method described in any one of claims 14 to 16.

18. A storage medium (30b) on which the program according to claim 17 is stored.

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