Distance calculation device

Abstract

This method accurately determines the remaining driving range, which changes as the energy storage device heats up during driving prior to charging. [Solution] A distance calculation device for determining the distance that an electric vehicle can travel is equipped with a power storage device for storing electricity for driving and a heater for heating the power storage device using the power of the power storage device, and the device has a controller that determines the distance that can travel using the power of the power storage device when the power storage device is heated by the heater and the temperature rises while driving using the power of the power storage device, and the controller has a calculation unit (step S3) that adds the amount of electricity gradually consumed by raising the temperature of the power storage device while driving to the amount of electricity consumed by driving and determines the distance that can travel.

Description

Technical Field

[0001] The present invention relates to a device for determining the driving distance of an electric vehicle that can travel using the power of a power storage device, and more particularly to a device for determining the distance that can be traveled with the remaining power in the power storage device.

Background Art

[0002] As this type of electric vehicle, electric vehicles (BEVs) and plug-in hybrid vehicles (PHEVs) are known. These electric vehicles are equipped with a large-capacity power storage device and drive a motor with the power thereof to travel. Therefore, when the remaining charge amount (SOC: State Of Charge) in the power storage device, which is the energy source, decreases, it is necessary to move to a location where charging facilities such as a charging stand are installed to perform charging. Therefore, in an electric vehicle, there may be provided a device that displays the SOC and its decrease to prompt the driver to charge, or a device that displays the travelable distance. This is the same as a conventional so-called gasoline vehicle.

[0003] As the power storage device of an electric vehicle, a secondary battery such as a lithium-ion battery is used. This type of secondary battery discharges as expected and has a shorter charging time when the temperature is relatively high. Therefore, for example, the battery device described in Patent Document 1 is configured to warm the secondary battery by a plurality of heaters provided on a warming plate. Further, in the battery device described in Patent Document 1, the secondary battery is warmed during travel when the ignition switch is on, and when the battery temperature becomes higher than the set temperature, the power supply to the heater is stopped.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] The secondary battery is heated using the battery's own power. Heating the secondary battery requires a large amount of power, and the power consumption increases especially in winter when the outside temperature is low. Since the secondary battery to be heated also powers the motor that drives the electric vehicle, heating the secondary battery while driving prior to charging will lower the battery's State of Charge (SOC), shortening the driving range or cruising range (hereinafter referred to as "driving range"). The displayed driving range is important data for the driver to determine the timing of charging, so it is required that the display of the driving range be accurate. However, conventionally, the calculation and display control of the driving range when so-called preconditioning, which involves heating the energy storage device to raise its temperature, has not been sufficiently considered, and there was room to develop new technologies related to the management of the driving range, including the calculation and display of the driving range that changes with preconditioning.

[0006] This invention has been made in view of the above technical problems, and aims to provide a driving distance calculation device that can accurately determine the driving distance that changes as the temperature of the energy storage device rises during driving prior to charging. [Means for solving the problem]

[0007] To achieve the above objective, the present invention provides a mileage calculation device for determining the mileage of an electric vehicle comprising a power storage device for storing power for driving and a heater for heating the power storage device using the power of the power storage device, wherein the device includes a controller for determining the mileage using the power of the power storage device when the power storage device is heated by the heater during driving using the power of the power storage device, and the controller includes a calculation unit that adds the amount of power gradually consumed by raising the temperature of the power storage device while driving to the amount of power consumed by driving to determine the mileage.

[0008] In the present invention, the calculation unit may be configured to determine the drivable distance based on a combined power consumption rate that includes the power consumption rate obtained by the electric vehicle in motion and the power consumption rate during temperature rise when power is consumed to achieve the target temperature, and the remaining charge of the energy storage device.

[0009] In the present invention, the calculation unit may be configured to determine the drivable distance when the remaining charge of the energy storage device at the time a request for the energy storage device to raise its temperature is made is less than or equal to a predetermined value.

[0010] In the present invention, the calculation unit may be configured to determine the drivable distance when the remaining charge obtained by subtracting the amount of power required to raise the energy storage device to a predetermined target temperature from the remaining charge of the energy storage device at the time a request for raising the temperature of the energy storage device is made is less than or equal to a predetermined value.

[0011] In the present invention, the controller may further include another calculation unit that determines the driving distance that can be traveled with the remaining power amount obtained by subtracting the amount of heating power required to achieve the target temperature of the energy storage device when there is a request to heat the energy storage device with the heater from the remaining charge of the energy storage device. [Effects of the Invention]

[0012] According to the present invention, if the energy storage device is heated while the vehicle is in motion, the remaining charge of the energy storage device gradually decreases while heating and driving, and the driving distance is calculated according to the rate of decrease. In other words, the power (heat) required to heat up the energy storage device is determined by the amount of temperature rise and the heat capacity, but if that amount of power is subtracted all at once from the remaining charge at the time the heating request is made, and the driving distance is calculated using the remaining power after the subtraction, the driving distance will be shortened, and situations may arise such as continuing to heat the device even after driving that distance, i.e., there is still power remaining that can be used for driving. In contrast, the present invention calculates the driving distance while using power for both driving and heating, so it is possible to accurately determine the distance that can be driven using all the power, i.e., the driving distance that corresponds to the actual remaining charge. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram showing an example of a vehicle in an embodiment of the present invention. [Figure 2] The following are examples of display content on the display unit: (a) is a schematic diagram showing an example of an icon that functions as a selection switch, and (b) is a schematic diagram showing an example of the display of the remaining driving distance. [Figure 3] This diagram shows the temperature change of the energy storage device in manual heating mode and in automatic heating mode. [Figure 4] This is a block diagram showing the functional configuration of the controller. [Figure 5] This is a flowchart illustrating an example of control performed by the controller. [Figure 6] The diagram shows the change between the first and second driving ranges, where (a) shows an example where the SOC in the energy storage device is sufficiently large, and (b) shows an example where the SOC in the energy storage device is small. [Modes for carrying out the invention]

[0014] Next, an example of the present invention will be described with reference to the attached drawings. Note that the embodiments described below are merely examples of how the present invention may be implemented and do not limit the present invention.

[0015] The mileage calculation device according to the present invention is a device for calculating the mileage that an electric vehicle (BEV) or plug-in hybrid vehicle (PHEV) (hereinafter simply referred to as "vehicle") 1 can travel when it consumes electricity to run. An example of such a vehicle 1 is schematically shown in Figure 1. The drive source 2 is equipped with an electric motor such as a motor generator, and a power storage device 3 is mounted on the vehicle 1 to supply power to the drive source 2 and to charge the power generated by the electric motor. Therefore, the power storage device 3 may be composed of a secondary battery such as a lithium-ion battery. Since the power storage device 3 has characteristics in which the charging and discharging performance differs depending on its temperature, a heater 4 is provided to heat the power storage device 3 to a target temperature in which the charging and discharging performance is optimized and raise its temperature (heat rise). The heater 4 may be configured to have its own heat source, or it may be configured to heat the power storage device 3 by utilizing the heat from a heat source in the air conditioning system 5. In any case, the power of the power storage device 3 is used to raise the temperature of the power storage device 3.

[0016] A control device (controller) 6 is provided to control the temperature rise of the energy storage device 3 by the heater 4. The controller 6 is mainly composed of a microcomputer consisting of an arithmetic unit (CPU), memory elements (ROM, RAM, SRAM), and interfaces. Using the input data and pre-stored data, it performs calculations according to a pre-prepared program and outputs the result of the calculation as a control command signal. An example of the input data is the on / off signal of the main switch 7. The main switch 7 is a switch that activates the entire vehicle 1 when turned on and deactivates the entire vehicle 1 when turned off, and is sometimes called an ignition switch or ready switch. Note that the controller 6 can operate even when the main switch 7 is in the off state.

[0017] In addition, since the controller 6 is for controlling the temperature of the power storage device 3, the detection signal of the temperature sensor 8 that detects the temperature of the power storage device 3 and the detection signal of the outside air temperature sensor 9 that detects the outside air temperature are input to the controller 6.

[0018] As modes for controlling the temperature rise of the power storage device 3, the controller 6 includes a manual temperature rise mode (hereinafter referred to as the manual mode) and an automatic temperature rise mode (hereinafter referred to as the automatic mode). The manual mode is a form of control in which a passenger such as a driver of the vehicle manually operates to start the temperature rise and ends the temperature rise when a predetermined end condition such as the temperature of the power storage device 3 reaching the target temperature is satisfied. The automatic mode is a form of control in which the temperature rise is started based on a signal detecting the state of the vehicle 1 such as the position of the vehicle 1 and ends the temperature rise when a predetermined end condition such as the temperature of the power storage device 3 reaching the target temperature is satisfied. A signal of a selection switch 10 for selecting these control modes is input to the controller 6.

[0019] The selection switch 10 may be a contact switch such as a push switch or a touch-type switch that appears as an icon on a display 11 provided with a touch panel. FIG. 2(a) shows an example of an icon as the selection switch 10 that appears on the display 11, where "M" indicates an icon for selecting the manual mode and "A" indicates an icon for selecting the automatic mode. These switches are, for example, switches that switch between on and off each time they are touched, and may be configured such that when one of them is touched while the other is lit, one is switched off and the other is switched on.

[0020] Here, the manual mode and the automatic mode will be described. The manual mode is a control mode in which, in preparation for charging by a charging facility not shown in the figure, when the vehicle 1 is running or when the main switch 7 described above is in the ON state, the manual mode is selected by the selection switch 10, and the heater 4 is operated to raise the temperature. An example of the change in the temperature of the power storage device 3 in that case is shown in FIG. 3. FIG. 3 is a diagram with the temperature of the power storage device 3 on the vertical axis and time on the horizontal axis. The line indicated by the symbol "M" shows the change in the manual mode, and the line indicated by the symbol "A" shows the change in the automatic mode. When the manual mode is selected by the selection switch 10 at the time point t0, the heater 4 is energized and the heating of the power storage device 3 starts, and the temperature of the power storage device 3 gradually rises. The way the temperature rises is determined by factors such as the heat generation amount of the heater 4, the thermal resistance between the heater 4 and the power storage device 3, and the heat dissipation amount from the power storage device 3 that is affected by the outside air temperature, etc.

[0021] The temperature of the power storage device 3 suitable for charging varies depending on the charging capacity of the charging facility. If it is about 50 kW, it is about T0 °C, if it is 90 kW, it is about T1 (> T0) °C, and if it is 150 kW, it is about T2 (> T1) °C. When charging is not particularly scheduled, or even if charging is scheduled but the capacity of the charging facility for performing that charging is unknown, the temperature corresponding to the assumed maximum capacity (for example, T2 °C) is used as the target temperature to raise the temperature. Therefore, in the example shown in FIG. 3, at the time point t1 when the detected temperature of the power storage device 3 reaches the target temperature, the power supply to the heater 4 is stopped, and the temperature rise of the power storage device 3 is stopped. After that, the temperature of the power storage device 3 gradually decreases due to natural heat dissipation.

[0022] The automatic mode is a control mode that, provided that automatic mode is selected, performs a temperature increase of the energy storage device 3 based on the state of vehicle 1. The state of vehicle 1 is mainly the distance from the vehicle's current location to the charging equipment, or the time it will take to reach the charging equipment. The charging equipment may be equipment at a location detected based on map data, or it may be equipment at a location set as a target location. Therefore, in automatic mode, temperature control is performed based on the vehicle's current location and the location of the charging equipment, and data obtained from the navigation system 12 is used. The navigation system 12 is a system that determines the location of vehicle 1 and the charging equipment using GPS (Global Positioning System), and determines the location of vehicle 1 and the charging equipment on the map by overlaying the GPS location information onto pre-prepared map data. Therefore, the navigation system 12 can determine the distance from the current location to the charging equipment, and the time or date it will take to reach the charging equipment when traveling at a predetermined vehicle speed. In addition, the capacity of the charging equipment can be obtained from the navigation system 12 by pre-storing it in the navigation system 12.

[0023] On the other hand, based on the difference between the current temperature of the energy storage device 3 and the target temperature, the time required to raise the temperature to the target temperature can be determined. From this time and the vehicle speed, the timing for starting the heating process, such as the time to start heating or the distance from the charging equipment, can be determined. Therefore, if the target charging equipment is a 150kW facility, heating will start at time t3, as indicated by the symbol "A" in Figure 3. If it is a 90kW facility, heating will start at time t4, when the vehicle is closer to the charging equipment. In addition, even in automatic mode, heating will stop when the temperature of the energy storage device 3 reaches the target temperature.

[0024] The controller 6 uses input data and pre-stored data to control the heating of the energy storage device 3, including starting or stopping heating, and prohibiting or allowing further heating. In addition, it calculates the distance that can be traveled with the amount of electricity stored in the energy storage device 3 and displays the calculated distance on the aforementioned display unit 11. Therefore, the controller 6 corresponds to the controller in the present invention in terms of its function of calculating and displaying the distance that can be traveled. The functional configuration of the controller 6 for calculating the distance that can be traveled is shown in a block diagram in Figure 4.

[0025] The controller 6 is equipped with a data acquisition unit 6a. The data acquisition unit 6a receives data obtained from various sensors and also reads pre-prepared data. Examples of this data include the temperature rise request when the selection switch 10 is operated, the remaining charge (SOC) of the energy storage device 3, the temperature of the energy storage device 3, the target temperature of the energy storage device 3, the heat capacity of the energy storage device 3 and heaters, the driving power consumption rate which is the relationship between the amount of power consumed by the drive source 2 and the amount of power consumed by auxiliary equipment when the vehicle 1 is running and the distance traveled at that time, and the heating power consumption rate which is the relationship between the amount of power consumed to raise the energy storage device 3 to the target temperature and the distance traveled. This data can be obtained from a computer that controls the drive source 2 or a computer that controls the air conditioning system 5, or it can be obtained by reading data that has been pre-stored in a predetermined memory element. The driving power consumption rate and the heating power consumption rate may be calculated from the amount of power, distance traveled or driving time obtained when the vehicle 1 has been running in the past, or they may be design values ​​that have been determined in advance through experiments or simulations.

[0026] The controller 6 includes a first calculation unit 6b for determining the first possible driving distance and a second calculation unit 6c for determining the second possible driving distance. The first possible driving distance is the distance that the vehicle 1 can travel with the remaining energy remaining after subtracting the amount of energy required to raise the temperature of the energy storage device 3 (i.e., the amount of energy required for heating) from the State of Charge (SOC) of the energy storage device 3 at that time, in the event that the energy storage device 3 is requested to raise its temperature while the vehicle 1 is in motion. In this case, the amount of energy required to raise the temperature of the energy storage device 3 can be determined based on the temperature difference between the current temperature of the energy storage device 3 and the target temperature, and the heat capacity of the energy storage device 3, the heater 4 itself, and related parts whose temperature rises when heated by the heater 4. This amount of energy may also be obtained from a map that defines the amount of energy based on the temperature difference.

[0027] The first possible driving distance can be determined from the remaining energy and the driving energy consumption rate. Here, the driving energy consumption rate can be determined from data obtained by the actual driving of vehicle 1. For example, it can be determined based on the amount of power consumed (power consumption) by the drive source 2 (more specifically the motor) during driving before the time when the heating request was made, the amount of energy Wo consumed by auxiliary equipment such as the air conditioning system 5 during that driving, and the driving distance Lo of vehicle 1 when these amounts of energy Wo were measured. More specifically, the driving energy consumption rate can be obtained by dividing the measured amount of energy by the driving distance. To illustrate this with a calculation formula, if the amount of energy required for heating is "Wh" and the driving energy consumption rate (first energy consumption) is "αr", then the first possible driving distance L1 is: L1=(SOC-Wh)×1 / αr :(αr=Wo / Lo) Thus, the first calculation unit 6a that calculates the first drivable distance L1 corresponds to the "other calculation unit" in the present invention.

[0028] Furthermore, the second possible driving distance is the driving distance determined by taking into account the power gradually consumed as the energy storage device 3 heats up while driving. This distance is calculated assuming that when the vehicle 1 is driving and a request to heat up the energy storage device 3 is made, the state of charge (SOC) of the energy storage device 3 at that time is consumed by driving the power source 2 and heating the energy storage device 3, that is, when power is consumed by both driving and heating. Therefore, the second possible driving distance can be calculated from the sum of the power consumption rate when driving using power consumed by the power source 2 and the power consumption rate when heating the energy storage device 3 and consuming power at the same time, and the SOC of the energy storage device 3. Here, the power consumption rate when driving is as described above. The power consumption rate when heating is as follows.

[0029] First, the amount of electricity consumed during the heating of the energy storage device 3 can be determined, as mentioned above, by the temperature rise to the target temperature and the heat capacity. Furthermore, the temperature rise gradient of the energy storage device 3 is determined by the heat output of the heater 4 and the heat transfer coefficient between the heater 4 and the energy storage device 3, and can be determined in advance through experiments or simulations using actual equipment. Therefore, the time required to reach the target temperature can be determined from the amount of electricity consumed and the temperature rise gradient, and the distance traveled by the vehicle 1 during that time can be determined. The power consumption rate during heating can then be calculated from the distance thus determined and the amount of electricity consumed during heating. This power consumption rate during heating may be calculated each time a heating request is made during operation, but it may also be prepared in advance as an approximate value through experiments or simulations. The second possible driving distance L2 can essentially be determined from the amount of electricity that can be consumed and the power consumption rate that takes into account the temperature rise of the energy storage device 3. This power consumption rate that takes into account the temperature rise of the energy storage device 3 is the sum of the aforementioned driving power consumption rate and the power consumption rate during temperature rise. To illustrate the calculation formula, if the amount of electricity consumed during temperature rise while driving is "Wh" and the sum of the power consumption rates (second power consumption rate) is "αh", then the second possible driving distance L2 is: L2=SOC×1 / αh :(αh=(Wo+Wh) / Lo) Thus, the second calculation unit 6b that calculates the second drivable distance L2 corresponds to the "calculation unit" in the present invention.

[0030] Furthermore, the controller 6 is equipped with a third calculation unit 6d. The third calculation unit 6d determines the third possible driving distance L3 while driving in a state where there is no need to raise the temperature of the energy storage device 3. Since there is no need to raise the temperature of the energy storage device 3, the power stored in the energy storage device 3, i.e., the State of Charge (SOC), is consumed by the drive power source 2 and auxiliary equipment such as the air conditioning system 5, just as in normal driving. Therefore, the third possible driving distance L3 is calculated from the SOC of the energy storage device 3, the aforementioned driving power consumption rate (first energy consumption) αr, and the SOC of the energy storage device 3. L2 = SOC × 1 / αr : (αr = Wo / Lo) It can be calculated using this method.

[0031] The controller 6 is provided with an output unit 6e that outputs one of the first to third drivable distances L1, L2, or L3 described above as a control instruction signal. This control instruction signal may be a signal to display the drivable distance on the display unit 11, or it may be a signal for some kind of notification or a signal to perform some kind of control for raising the temperature of the energy storage device 3. For example, when there is a request to raise the temperature of the energy storage device 3, the output unit 6e displays the larger of the first drivable distance L1 and the second drivable distance L2, L1 (or L2), on the display unit 11, and when there is no request to raise the temperature of the energy storage device 3, it displays the third drivable distance L3 on the display unit 11. Figure 2(b) schematically shows an example of how the drivable distance is displayed on the screen of the display unit 11.

[0032] Next, an example of the control performed by the controller 6 described above will be explained. Figure 5 is a flowchart illustrating this example of control, and the routine shown here is repeatedly executed when the main switch 7 mentioned above is ON and the vehicle 1 is running. First, in step S1, it is determined whether or not the temperature rise control is being performed. This temperature rise control may be either the manual mode or the automatic mode control mentioned above. Also, "being performed" means that the heater 4 is emitting heat and has started heating the energy storage device 3. Therefore, the determination in step S1 can be made by detecting whether or not the heater 4 is emitting heat.

[0033] If the result of the judgment in step S1 is "yes," the first and second possible driving distances L1 and L2 are calculated as described above. The order of these calculations is arbitrary; in the example shown in Figure 5, the first possible driving distance L1 is calculated in step S2 and the second possible driving distance L2 is calculated in step S3. As described above, the first possible driving distance L1 is determined by subtracting the amount of electricity Wh required to raise the temperature of the energy storage device 3 from the State of Charge (SOC) of the energy storage device 3 at that time, and the driving power consumption rate (first energy consumption) αr obtained from the previous drive. An example of the calculation formula is as described above. Similarly, the second possible driving distance L2 can be determined by the combined power consumption rate (second energy consumption) αh, which takes into account the power consumption rate due to raising the temperature of the energy storage device 3 during driving, and the SOC of the energy storage device 3 at that time. An example of the calculation formula is as described above.

[0034] Next, in step S4, it is determined which of the first drivable distance L1 and the second drivable distance L2 is larger. For example, in step S4, it is determined whether the first drivable distance L1 is greater than or equal to the second drivable distance L2. Then, control is performed to display the larger drivable distance on the display unit 11. In the example shown in Figure 5, if the result of the determination in step S4 is "yes", the first drivable distance L1 is displayed in step S5 and the routine shown in Figure 5 is terminated. Conversely, if the result of the determination in step S4 is "no", the second drivable distance L2 is displayed in step S6 and the routine shown in Figure 5 is terminated.

[0035] On the other hand, if the result of the judgment in step S1 is "no" because there is no request for the energy storage device 3 to heat up during driving, the process proceeds to step S7 to calculate the third possible driving distance L3. An example of the calculation formula is as described above. Then, in step S8, control is executed to display the third possible driving distance L3, and the routine shown in Figure 5 is terminated.

[0036] Here, we will explain the situation in which a difference in magnitude occurs between the first possible driving distance L1 and the second possible driving distance L2. Figure 6 shows the temporal change in the possible driving distance after the heating of the energy storage device 3 is started based on the request for heating. Figure 6(a) shows an example when the SOC is sufficiently large, and (b) shows an example when the SOC is small. The SOC of the energy storage device 3 gradually decreases as it consumes power in the drive power source 2 and also in auxiliary equipment such as the air conditioning system 5. Consequently, the possible driving distance gradually decreases. The rate of decrease in this case is the same as the rate of power consumption (first power consumption) αr mentioned above. That is, the possible driving distance at this point is the third possible driving distance L3 mentioned above. The display unit 11 shows the third possible driving distance L3.

[0037] When the heating of the energy storage device 3 begins at time t10 during travel, the initial power consumption reduces the available travel distance by a predetermined amount. For the first available travel distance L1, this reduction is calculated to be the amount of electricity Wh required to heat up the energy storage device 3, as shown by the solid line in Figure 6(a). The first available travel distance L1 then decreases at a gradient corresponding to the power consumption rate (first energy consumption) αr obtained in the previous trip. In this case, if the available travel distance is sufficiently large, for example, by subtracting the amount of electricity Wh required to heat up the energy storage device 3 from the SOC at time t10, the first available travel distance L1 can be covered, and the display unit 11 will show the first available travel distance L1.

[0038] The example shown in Figure 6(a) is one in which the State of Charge (SOC) of the energy storage device 3 is sufficiently high. Even when driving while the energy storage device 3 is being heated as described above, there is still a margin in the SOC, and the vehicle 1 can continue to run. Therefore, the driving range displayed on the display unit 11 is accurate and matches the actual situation of the vehicle 1. Furthermore, since drivers generally desire the longest possible driving range, seeing a large value for the first driving range L1 provides a sense of security and allows them to confirm the vehicle's performance.

[0039] An example of a case where the State of Charge (SOC) of the energy storage device 3 is low will be explained with reference to Figure 6(b). When the heating of the energy storage device 3 begins at time t20 while the vehicle 1 is in motion, both the calculated first possible travel distance L1 and the second possible travel distance L2 decrease by a predetermined amount. The first possible travel distance L1, shown by the dashed line in Figure 6(b), decreases significantly in proportion to the amount of electricity Wh required for heating, while the second possible travel distance L2 decreases slightly in proportion to the unavoidable power consumption in the initial stages of heating. Subsequently, the first possible travel distance L1 and the second possible travel distance L2 each decrease at the predetermined gradient described above.

[0040] As shown by the dashed line in Figure 6(b), the first drivable distance L1 gradually decreases from the drivable distance corresponding to the so-called remaining energy amount, which is obtained by subtracting the amount of energy Wh required to raise the temperature of the energy storage device 3 from the State of Charge (SOC) of the energy storage device 3. Therefore, at t21, a predetermined time has elapsed from t20 when the temperature rise begins, the first drivable distance L1 will fall below the destination distance. In other words, calculations show that it will not be possible to travel to the destination, and the temperature rise of the energy storage device 3 will also stop. However, at this point, at least a portion of the power required to raise the temperature of the energy storage device 3 remains, and the vehicle 1 can travel by using this power for driving. In contrast, as shown by the solid line in Figure 6(b), the second drivable distance L2, even if the decrease gradient is greater than the decrease gradient for the first drivable distance L1, begins to decrease from the drivable distance corresponding to the actual SOC of the energy storage device 3, so it maintains a value greater than the first drivable distance L1, and this is displayed on the display 11. Furthermore, such control, i.e., the calculation of the possible driving distance when driving while consuming power for both driving and heating, and the output of instruction signals based on the calculation results, may be performed, for example, when the amount of power obtained by subtracting the amount of power required to heat up the energy storage device 3 (Wh) from the SOC at time t20 is less than or equal to a predetermined value.

[0041] Therefore, when the State of Charge (SOC) of the energy storage device 3 is low and the energy storage device 3 is heated while driving, the driving range displayed on the display unit 11 will be the distance that can be traveled using the entire amount of SOC allowed in the energy storage device 3, and will be accurate and match the actual situation of the vehicle 1. As a result, even in this case, it is possible to avoid situations where the driver feels uneasy about the displayed driving range or the vehicle's performance.

[0042] It should be noted that the present invention is not limited to the specific examples described above. The first drivable distance can be determined based on the remaining energy amount obtained by subtracting the amount of energy required to raise the temperature of the energy storage device from the State of Charge (SOC) of the energy storage device, and the second drivable distance can be determined based on the SOC of the energy storage device. The calculation of these drivable distances is not limited to the calculation formulas described above. Furthermore, the power consumption rate during driving and the power consumption rate during temperature rise in the present invention may be defined by adding other parameters depending on the characteristics and configuration of the vehicle. [Explanation of symbols]

[0043] 1 vehicle 2. Power source 3. Energy storage device 4 Heaters 5. Air conditioning system 6 Controllers 6a Data acquisition unit 6b 1st calculation part 6c 2nd calculation part 6d 3rd calculation part 6e Output section 7 Main Switch 8. Temperature sensor 9. Outdoor temperature sensor 10 Selector switches 11 Display 12 Navigation System L1 First driving distance L2 Second driving range L3 Third driving range Low mileage Wh, Wo Energy

Claims

1. A distance calculation device for determining the distance that an electric vehicle can travel, comprising a power storage device for storing electricity for driving and a heater for heating the power storage device using the power from the power storage device, The system includes a controller that determines the distance that can be traveled using the power of the energy storage device, assuming that the energy storage device is heated by the heater to raise its temperature while the device is being driven using the power of the energy storage device. The aforementioned controller, The system includes a calculation unit that determines the remaining driving distance by adding the amount of electricity gradually consumed by raising the temperature of the energy storage device while driving to the amount of electricity consumed by driving. A device for calculating mileage, characterized by the following features.

2. A mileage calculation device according to claim 1, The calculation unit is configured to determine the drivable distance based on a combined power consumption rate, which includes the power consumption rate obtained by the electric vehicle in motion and the power consumption rate during temperature rise when power is consumed to achieve the target temperature of the energy storage device, and the remaining charge of the energy storage device. A device for calculating mileage, characterized by the following features.

3. A mileage calculation device according to claim 1 or 2, The calculation unit is configured to determine the drivable distance when the remaining charge of the energy storage device at the time a request for the energy storage device to raise its temperature is made is less than or equal to a predetermined value. A device for calculating mileage, characterized by the following features.

4. A mileage calculation device according to claim 3, The calculation unit is configured to determine the drivable distance if the remaining charge, obtained by subtracting the amount of electricity required to raise the energy storage device to a predetermined target temperature from the remaining charge of the energy storage device at the time a request for raising the temperature of the energy storage device is made, is less than or equal to a predetermined value. A device for calculating mileage, characterized by the following features.

5. A mileage calculation device according to claim 1 or 2, The aforementioned controller, The system further includes another calculation unit that determines the driving distance that can be traveled using the remaining energy obtained by subtracting the amount of heating energy required to achieve the target temperature of the energy storage device when there is a request to heat the energy storage device with the heater from the remaining charge of the energy storage device. A device for calculating mileage, characterized by the following features.

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