JP6136950B2 - Driving distance calculation system - Google Patents

Description

  The present invention relates to a travelable distance calculation system, and more particularly to a travelable distance calculation system for a vehicle including a rotating electrical machine and a power storage device that supplies electric power to the rotating electrical machine.

  The hybrid vehicle can run using only the electric power of the battery with the engine stopped. The traveling performed with the engine stopped in this manner is referred to as “EV traveling”. In a hybrid vehicle, there is a high need for grasping the maximum distance that enables EV travel (hereinafter also referred to as EV travel possible distance). In order to calculate the EV travelable distance with high accuracy, it is necessary to improve the estimation accuracy of the state of charge (SOC) of the battery.

  For example, in a power storage system disclosed in Japanese Patent Application Laid-Open No. 2013-158087 (Patent Document 1), a controller calculates an integrated value of a charging current and a discharging current of a battery. In the memory of this controller, first relation data (specifically, an SOC-OCV (Open Circuit Voltage) curve) associated with a state where the integrated value of the discharge current is larger than the integrated value of the charging current, and the charging Second relational data associated with a state where the integrated value of current is larger than the integrated value of discharge current is stored. The controller selects one of the first and second relation data, and calculates the SOC from the OCV according to the selected relation data.

JP2013-158087A

  It is known that battery polarization occurs when the battery is charged and discharged. When the battery is charged, the polarization voltage increases in the positive direction, and when the battery is discharged, the polarization voltage increases in the negative direction. The polarization voltage is not eliminated as soon as the charging / discharging of the battery is stopped. The polarization voltage gradually decreases with time after charging and discharging are stopped. In other words, in order to eliminate the polarization, it is necessary that a certain time elapses after the charge / discharge is stopped.

  However, Patent Document 1 does not particularly describe that the SOC is estimated in consideration of the elimination of the polarization, and further, the EV travelable distance is calculated from the estimated SOC.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a technique for improving the calculation accuracy of the EV travelable distance of the vehicle.

  A travelable distance calculation system according to an aspect of the present invention is a travelable distance calculation system for a vehicle including a rotating electrical machine and a power storage device capable of supplying driving power to the rotating electrical machine. The vehicle has a first mode in which traveling using the electric power of the power storage device is permitted, and a second mode in which traveling using the electric power of the power storage device is prohibited. The battery is configured to be capable of external charging that charges the power storage device with the power supplied from. The travelable distance calculation system includes an estimation unit that estimates a charge state from a voltage according to characteristics indicating a relationship between a charge state of the power storage device and a voltage of the power storage device, and travel of the vehicle using the power of the power storage device from the charge state. A calculation unit for calculating a possible distance; a first period from the time of transition to the second mode to the start of external charging; and a second period from the end of external charging to the time of transition to the first mode. A measurement unit for measuring the period. The calculation unit calculates a travelable distance from the state of charge immediately before the transition to the first mode at the time of transition to the first mode, and further calculates the travelable distance based on the first and second periods. to correct.

  The charge / discharge control of the power storage device is not performed in the period from the transition to the second mode to the start of external charging and in the period from the end of the external charging to the transition to the first mode. When a certain period of time elapses without charging / discharging, since the polarization of the power storage device has been eliminated, the state of charge of the power storage device can be accurately estimated. According to the above configuration, the travelable distance is corrected in consideration of the period after the charge / discharge of the power storage device is completed. Therefore, the calculation accuracy of the travelable distance of the vehicle can be improved.

  Preferably, the characteristics include a first characteristic when the power storage device is charged and a second characteristic when the power storage device is discharged. The estimation unit selects a corresponding characteristic from the first and second characteristics depending on whether the power storage device is being charged or discharged immediately before the vehicle shifts to the second mode, According to the selected characteristics, the state of charge immediately before the start of external charging is estimated. A calculation part correct | amends the driving | running | working distance calculated at the time of transfer to 1st mode based on the charge state just before the start of external charging.

  Since charge / discharge control is not performed from the transition to the second mode to the start of external charging, if the power storage device is being charged immediately before the transition to the second mode, immediately before the start of external charging The power storage device is polarized in the charging direction. On the other hand, when the power storage device is being discharged immediately before the transition to the second mode, the power storage device is polarized in the direction of discharge immediately before the start of external charging. The corresponding characteristic is selected from the first and second characteristics according to the state of the power storage device immediately before the transition to the first mode. Therefore, the state of charge immediately before the start of external charging can be accurately estimated. Therefore, the accuracy can be improved when the travelable distance is corrected based on the state of charge immediately before the start of external charging.

  According to the present invention, the calculation accuracy of the EV travelable distance of the vehicle can be improved.

It is a block diagram which shows roughly the travelable distance calculation system which concerns on this Embodiment. It is a figure which shows an example of the SOC-OCV curve of this Embodiment. 3 is a functional block diagram of an ECU 300 and a server 2. FIG. It is a figure for demonstrating the period measured by the period measurement part 306. FIG. It is a flowchart which shows the process which calculates EV driving | running | working possible distance. It is a figure which shows the calculation process of the 1st EV driving | running | working distance shown in FIG. 5 in detail. It is a figure which shows the calculation process of the 2nd EV travel possible distance shown in FIG. 5 in detail.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is a block diagram schematically showing a travelable distance calculation system according to the present embodiment. Referring to FIG. 1, vehicle 1 is a plug-in hybrid vehicle. That is, the vehicle 1 is configured to be able to charge a battery mounted on the vehicle (hereinafter, also referred to as external charging) with electric power supplied from outside the vehicle.

  The vehicle 1 includes a driving force generator 10, a power supply system 20, an ECU (Electronic Control Unit) 300, an ignition switch 40, and a monitor 42. Driving force generation unit 10 includes an engine 100, a first MG (Motor Generator) 101, a second MG 102, a power split device 104, driving wheels 106, and inverters 111 and 112.

  ECU 300 has a function of supervising control during traveling of vehicle 1 and during external charging. ECU 300 is configured to achieve a desired control function by predetermined arithmetic processing by execution of a program stored in advance in memory 350 or by predetermined arithmetic processing by hardware such as an electronic circuit.

  Engine 100, first MG 101, and second MG 102 are coupled to power split device 104. Vehicle 1 travels by driving force from at least one of engine 100 and second MG 102. The power generated by the engine 100 is divided into two paths by the power split device 104. One is a path transmitted to the drive wheel 106 and the other is a path transmitted to the first MG 101.

  Each of first MG 101 and second MG 102 is an AC rotating electric machine, for example, a three-phase AC rotating electric machine including a rotor in which a permanent magnet is embedded. First MG 101 generates power using the power of engine 100 divided by power split device 104. For example, when the SOC of battery 50 decreases, engine 100 starts and power generation by first MG 101 is performed. The electric power generated by the first MG 101 is supplied to the power supply system 20.

  Second MG 102 generates driving force using at least one of the power supplied from power supply system 20 and the power generated by first MG 101. The driving force of second MG 102 is transmitted to driving wheel 106. Note that, during regenerative braking of the vehicle, the second MG 102 is driven by the drive wheels 106, and the second MG 102 operates as a generator. Thus, second MG 102 operates as a regenerative brake that converts braking energy into electric power. The electric power generated by the second MG 102 is supplied to the power supply system 20.

  Power split device 104 includes a planetary gear (all not shown) including a sun gear, a pinion gear, a carrier, and a ring gear. The pinion gear engages with the sun gear and the ring gear. The carrier supports the pinion gear so as to be capable of rotating, and is connected to a crankshaft (not shown) of engine 100. The sun gear is connected to a rotation shaft (not shown) of first MG 101. The ring gear is connected to a rotation shaft (not shown) of second MG 102.

  Inverters 111 and 112 convert drive power (DC power) supplied from power supply system 20 into AC power and supply the AC power to first MG 101 and second MG 102, respectively. Inverters 111 and 112 convert AC power generated by first MG 101 and second MG 102 to DC power, respectively, and supply the DC power to power supply system 20 as regenerative power. Each of inverters 111 and 112 includes, for example, a bridge circuit including switching elements for three phases. Each of inverters 111 and 112 drives a corresponding MG by performing a switching operation in accordance with a drive signal from ECU 300.

  ECU 300 calculates vehicle required power Ps based on detection signals of respective sensors (not shown), travel conditions, accelerator opening, and the like, and torque target values and rotations of first MG 101 and second MG 102 based on the calculated vehicle required power Ps. Calculate the speed target value. ECU 300 controls inverters 111 and 112 so that the generated torque and rotation speed of first MG 101 and second MG 102 become target values.

  Power supply system 20 includes a battery 50, a voltage sensor 52, a current sensor 54, a temperature sensor 56, and a converter 60.

  The battery 50 is a rechargeable DC power source, and is, for example, a secondary battery such as a nickel metal hydride battery or a lithium ion battery, or a large capacity capacitor. Battery 50 is connected to converter 60 by power supply line 58p and ground line 58g. Converter 60 converts a voltage between battery 50 and driving force generation unit 10. System main relays SMR1, SMR2 are electrically connected to power supply wiring 58p and ground wiring 58g, respectively.

  The voltage sensor 52 detects the voltage VB of the battery 50. The current sensor 54 detects a current IB that is input to and output from the battery 50. The temperature sensor 56 detects the temperature TB of the battery 50. Each sensor outputs the detected value to ECU 300.

  ECU 300 also generates a drive signal for driving converter 60 based on voltage VB, current IB, and vehicle required power Ps. ECU 300 then outputs the generated drive signal to converter 60 to control converter 60.

  Power supply system 20 further includes a charger 24, a charging connector 26, and relays RL <b> 1 and RL <b> 2 as a configuration for external charging of battery 50.

  During external charging, a power source (hereinafter also referred to as an external power source) 400 outside the vehicle is electrically connected to the charging connector 26. The external power source 400 is generally composed of a commercial AC power source. The external power source 400 is provided with a charging plug 402 at the end of the charging cable. Charging connector 26 outputs connection signal CNT to ECU 300 when charging plug 402 is connected.

  The charger 24 is electrically connected to the charging connector 26. The charger 24 converts the AC voltage from the external power source 400 into a DC voltage for charging the battery 50. This DC voltage is output to the power supply wiring 22p and the ground wiring 22g. Relays RL1 and RL2 are electrically connected to power supply wiring 22p and ground wiring 22g, respectively.

  The ignition switch 40 is turned on / off by the driver of the vehicle 1. When the ignition switch 40 is turned on (IG-ON), an IG-ON signal is output from the ignition switch 40 to the ECU 300. When ECU 300 receives the IG-ON signal, ECU 300 switches system main relays SMR1, SMR2 from off to on. Thereby, the battery 50 is charged or discharged according to the operation of the driving force generator 10.

  On the other hand, when the ignition switch 40 is turned off (IG-OFF), an IG-OFF signal is output from the ignition switch 40 to the ECU 300. When ECU 300 receives the IG-OFF signal, it stops engine 100 and switches system main relays SMR1, SMR2 from on to off.

  However, even in the IG-OFF state, when the charging plug 402 is attached to the charging connector 26 for external charging, the system main relays SMR1, SMR2 and the relays RL1, RL2 are turned on. Therefore, AC power from the external power source 400 can be converted to a DC voltage by the charger 24 and transmitted to the battery 50.

  The IG-ON state corresponds to a “first mode” in which traveling using the power of the battery 50 is permitted. The IG-OFF state corresponds to a “second mode” in which traveling using the power of the battery 50 is prohibited.

  In the vehicle 1 having the above-described configuration, in the present embodiment, communication of various data is performed between the ECU 300 and the server 2. The server 2 calculates the SOC of the battery 50 and the EV travelable distance dEV of the vehicle 1 based on the data from the ECU 300, and transmits it to the vehicle 1. When ECU 300 receives EV travelable distance dEV from server 2, ECU 300 displays the value on monitor 42.

  FIG. 2 is a diagram showing an example of the SOC-OCV curve of the present embodiment. Referring to FIG. 2, the horizontal axis represents SOC and the vertical axis represents OCV. This SOC-OCV curve includes a charge side curve CHG (shown by a solid line) and a discharge side curve DCHG (shown by a broken line). The charging side curve CHG is a curve indicating the characteristic (first characteristic) when the battery 50 is charged. The discharge side curve DCHG is a curve showing the characteristic (second characteristic) when the battery 50 is discharged.

  When the temperature TB of the battery 50 is low, the internal resistance of the battery 50 increases, so the OCV increases. Therefore, the SOC-OCV curve as shown in FIG. 2 is prepared in advance for each temperature TB of the battery 50 (for example, every 5 ° C. from −5 ° C. to 50 ° C.) and stored in the memory (not shown) of the server 2. It is remembered. In the server 2, the SOC-OCV curve corresponding to the temperature TB is selected.

  The server 2 estimates the SOC from the OCV according to the selected SOC-OCV curve. The SOC estimation method will be described more specifically. The voltage sensor 52 detects a CCV (Closed Circuit Voltage) of the battery 50. The memory 350 of the ECU 300 stores a map for converting the CCV of the battery 50 into OCV (Open Circuit Voltage). ECU 300 converts CCV to OCV and transmits the OCV to server 2. On the other hand, the SOC-OCV curve is stored in the memory of the server 2. Therefore, the server 2 can estimate the SOC from the OCV.

  In the charging side curve CHG, the SOC for the same OCV is lower than that in the discharging side curve DCHG. Therefore, when the SOC is estimated from the OCV, the estimated value of the SOC differs depending on which curve is selected. If a curve corresponding to the charge / discharge state (charge state or discharge state) of the battery is not selected, an SOC error of, for example, about several percent may occur, as indicated by a dashed arrow in FIG. Further, when such an SOC error is converted into an EV travelable distance error, for example, in a vehicle capable of EV travel of 30 km in a fully charged state (SOC is 100%), the error can be about several kilometers. .

  On the other hand, as will be described later, in the present embodiment, a curve corresponding to the actual charge / discharge state of the battery 50 is selected. That is, in server 2, charging side curve CHG is selected when battery 50 is in a charged state, and discharging side curve DCHG is selected when battery 50 is in a discharged state. Therefore, the accuracy of the SOC can be improved.

  FIG. 3 is a functional block diagram of ECU 300 and server 2. Referring to FIG. 3, ECU 300 includes a charge / discharge state determination unit 302, an electric quantity calculation unit 304, a period measurement unit 306, a vehicle identification information holding unit 308, and a communication unit 310.

  The charge / discharge state determination unit 302 determines whether the battery 50 is in a charge state or a discharge state based on the detection value of the current sensor 54. More specifically, the current sensor 54 detects the current IB during discharging as a positive value and detects the current IB during charging as a negative value. Therefore, the charge / discharge state determination unit 302 determines that the battery 50 is in a discharged state when the current IB is a positive value, and determines that the battery 50 is in a charged state when the current IB is a negative value. To do.

  The electric quantity calculation unit 304 calculates the electric quantity Q1 (unit: Ah) supplied to the battery 50 during the external charging period by integrating the current IB.

  As described above, the polarization voltage gradually decreases with time after the charging / discharging of the battery is stopped. After a certain period of time has elapsed after stopping charging and discharging, the polarization of the battery 50 is almost eliminated, and the voltage of the battery 50 returns to the voltage before polarization. Therefore, the period measurement unit 306 measures a period for determining whether or not the polarization is eliminated.

  FIG. 4 is a diagram for explaining a period measured by the period measuring unit 306. Referring to FIG. 4, the start time (time 0) is in the IG-ON state. Thereafter, the IG-OFF operation is performed at time t1, and the IG-ON operation is performed again at time t4. Further, external charging is performed between time t2 and time t3. In the present embodiment, the periods L1, L2, and L3 are measured by the period measurement unit 306.

  Period L1 is a period from the time of IG-OFF (time t1) to the start of external charging (time t2). That is, the period L1 corresponds to a “first period”.

  The period L2 is a period from the end of external charging (time t3) to the time of IG-ON (time t4). That is, the period L2 corresponds to a “second period”.

  The period L3 is a period from the time of IG-OFF (time t1) to the time of IG-ON (time t4).

  Returning to FIG. 3, the vehicle specifying information holding unit 308 holds an information ID (hereinafter also referred to as vehicle specifying information) ID for the server 2 to specify the vehicle of the communication destination. The vehicle identification information ID is identification information unique to each vehicle, and for example, the chassis number (frame number) of the vehicle 1 can be used. Moreover, it is also possible to make each ECU hold | maintain identification information intrinsic | native to ECU, and to use the identification information as vehicle specific information ID.

  In addition, when using identification information intrinsic | native to ECU as vehicle specific information ID, it is preferable that the server 2 hold | maintains the data which link | connects the identification information and a vehicle body number. As a result, the server 2 can identify the vehicle even when using identification information unique to the ECU. Further, by using the identification information unique to the ECU in this way, even if the identification information is intercepted by a third party before being acquired by the server 2, the third party is prevented from specifying the vehicle. be able to.

  The communication unit 310 transmits the voltage VB and temperature TB of the battery 50, the amount of electricity Q1, the charge / discharge state at the time of IG-OFF, the periods L1 to L3, and the vehicle identification information ID of the vehicle 1 to the server 2.

  Server 2 includes an SOC estimation unit 202, a correction coefficient calculation unit 204, an EV travelable distance calculation unit 206, and a communication unit 208.

  As described with reference to FIG. 2, SOC estimation unit 202 calculates the SOC of battery 50 based on voltage VB and temperature TB.

  In general, a battery deteriorates as it is repeatedly charged and discharged, and the battery capacity gradually decreases. The EV travelable distance becomes shorter as the battery capacity decreases. That is, when the battery before deterioration and the battery after deterioration are compared, even when the same SOC is charged, the EV travelable distance is short with the battery after deterioration. For example, in a vehicle in which EV travel of 30 km is possible in a fully charged state (for example, SOC is 100%) in the initial capacity (for example, battery capacity at the time of battery manufacture), the battery capacity is 10 If it decreases by%, the EV travelable distance in the fully charged state (state where the SOC is 100%) decreases to 27 km. Therefore, the correction coefficient calculation unit 204 calculates a correction coefficient k for correcting the EV travelable distance according to the amount of decrease in battery capacity. A method for calculating the correction coefficient k will be described in detail later.

  EV travelable distance calculation unit 206 holds a relationship between SOC and EV travelable distance (for example, a map for converting SOC into EV travelable distance). EV travelable distance calculation unit 206 calculates EV travelable distance dEV from the SOC. Further, the EV travelable distance calculation unit 206 corrects the EV travelable distance dEV using the correction coefficient k. The corrected EV travelable distance dEV is transmitted to the vehicle 1 by the communication unit 208 of the server 2.

  The SOC estimation unit 202 corresponds to an “estimation unit”, the EV travelable distance calculation unit 206 corresponds to a “calculation unit”, and the period measurement unit 306 corresponds to a “measurement unit”.

  FIG. 5 is a flowchart showing a process for calculating the EV travelable distance dEV. Referring to FIG. 5, this flowchart is executed when a predetermined condition is satisfied or every time a predetermined period elapses. At the start of the flowchart, it is in the IG-ON state. Here, the steps of the flowchart are classified into cases 1 to 5 as shown in FIG.

[Case 1]
Case 1 is a case where a certain time has elapsed from the time of IG-OFF to the start of external charging, and a certain time has elapsed from the end of external charging to the time of IG-ON.

  In step S10, an IG-OFF operation is performed (see time t1 in FIG. 4). Thereafter, when external charging is started (see time t2 in FIG. 4, YES in step S20), the process proceeds to step S30.

  In step S30, ECU 300 determines whether or not period L1 is equal to or greater than a predetermined threshold value. That is, ECU 300 determines whether or not a certain time has elapsed from the time of IG-OFF to the start of external charging. This “predetermined time” is a predetermined time as a time from the IG-OFF until the polarization of the battery 50 is eliminated. If period L1 is equal to or greater than the threshold value (YES in step S30), the process proceeds to step S40.

  In step S40, ECU 300 transmits to server 2 voltage VB and temperature TB immediately before the start of external charging (for example, immediately before time t2 in FIG. 4), the charge / discharge state at the time of IG-OFF, and vehicle identification information ID. In step S50, external charging of the battery 50 ends (see time t3 in FIG. 4). Thereafter, when an IG-ON operation is performed in step S60 (see time t4 in FIG. 4), ECU 300 transmits period L2 to server 2. Thereafter, the process proceeds to step S70.

  In step S70, the server 2 determines whether or not the period L2 is equal to or greater than a predetermined threshold value. That is, the server 2 determines whether or not a certain time has elapsed from the end of external charging to the time of IG-ON. This “certain time” is a predetermined time as the time from the end of external charging until the polarization of the battery 50 is eliminated. The “certain time” in step S70 may be the same as the “certain time” in step S30, or may be determined independently. If period L2 is equal to or greater than the threshold value (YES in step S70), the process proceeds to step S80.

  In step S80, in response to a request from server 2, ECU 300 obtains voltage VB and temperature TB after external charging of battery 50, electric quantity Q1 energized during external charging, and vehicle identification information ID. Send to server 2. Here, voltage VB and temperature TB after the end of external charging are preferably values immediately before IG-ON (for example, immediately before time t4 in FIG. 4). This is because the possibility that the polarization of the battery 50 is eliminated increases as the time elapses from the end of the external charging. Thereafter, in step S90, the server 2 calculates the EV travelable distance dEV based on the first EV travelable distance calculation method.

  FIG. 6 is a diagram showing in detail the first EV travelable distance calculation process (the process of step S90) shown in FIG. Referring to FIG. 6, in step S <b> 901, server 2 obtains the SOC after the end of external charging. Specifically, the server 2 selects an SOC-OCV curve corresponding to the temperature TB acquired in step S80. After the external charging is finished, the battery 50 is polarized in the charging direction. Therefore, the server 2 selects the charging side curve CHG (see FIG. 2) and calculates the SOC from the voltage VB of the battery 50 (the value acquired in step S80).

  In step S902, the server 2 calculates an EV travelable distance dEV from the SOC. The following steps S903 to S906 are processes for correcting the EV travelable distance dEV in consideration of a decrease in battery capacity.

  In step S903, the server 2 obtains the SOC immediately before the start of external charging. Specifically, the server 2 selects the SOC-OCV curve corresponding to the temperature TB acquired in step S40. Next, the server 2 selects a corresponding curve from the charge side curve CHG and the discharge side curve DCHG according to the charge / discharge state at the time of IG-OFF acquired in step S40. That is, when the signal indicating the charge / discharge state from the ECU 300 indicates that the battery 50 is in the charged state at the time of IG-OFF, the server 2 selects the charging side curve CHG, while the signal is IG− When indicating that the battery 50 is in a discharged state at the time of OFF, the discharge side curve DCHG is selected. Further, the server 2 estimates the SOC from the voltage VB of the battery 50 (the value acquired in step S40) according to the selected curve.

  In step S904, the server 2 calculates the battery capacity C1 of the battery 50 after deterioration. Specifically, the server 2 obtains a difference ΔSOC between the estimated value of SOC in step S901 and the estimated value of SOC in step S903. Further, the server 2 calculates a value obtained by dividing the amount of electricity Q1 (unit: Ah) supplied to the battery 50 during the external charging period by the difference ΔSOC, and the battery capacity C1 (unit: Ah) of the deteriorated battery 50. ) (Q1 / ΔSOC = C1).

  In step S905, the server 2 calculates a value obtained by dividing the battery capacity C1 by the initial capacity C0 (known value) of the battery 50 as a correction coefficient k (k = C1 / C0). The calculated correction coefficient k is stored in a memory (not shown) of the server 2. When the correction coefficient k calculated last time is stored in the memory, the correction coefficient k is updated with a new value.

  In step S906, the server 2 corrects the EV travelable distance dEV by multiplying the updated correction coefficient k by the EV travelable distance dEV (the value obtained in step S902). Further, the server 2 transmits the corrected EV travelable distance dEV to the vehicle 1.

  Returning to FIG. 5, in step S <b> 100, the ECU 300 displays the EV travelable distance dEV from the server 2 on the monitor 42. When the process of step S100 ends, the entire process illustrated in FIG. 5 ends.

  Thus, in step S40, a corresponding curve is selected from the charge side curve CHG and the discharge side curve DCHG according to the charge / discharge state of the battery at the time of IG-OFF. Therefore, the estimation accuracy of the SOC can be improved.

  Further, in step S40, the voltage VB after a predetermined time has elapsed since IG-OFF is detected. Similarly, in step S80, voltage VB after a predetermined time has elapsed since the end of external charging is detected. That is, the voltage VB in steps S40 and S80 is a value after the polarization of the battery is eliminated. Therefore, in steps S901 and S903, the SOC can be accurately estimated based on the voltage VB after depolarization. As a result, the calculation accuracy of the EV travelable distance dEV can be improved.

[Case 2]
Case 2 is a case where a fixed time has elapsed from the time of IG-OFF to the start of external charging, but a fixed time has not elapsed from the end of external charging to the time of IG-ON.

  If period L2 is less than the threshold value in step S70 (NO in step S70), the process proceeds to step S81.

  In step S <b> 81, ECU 300 transmits voltage VB and temperature TB of battery 50 and vehicle identification information ID to server 2 in response to a request from server 2. That is, the process of step S81 differs from the process of step S80 in that the amount of electricity Q1 is not transmitted from the vehicle 1 to the server 2. Thereafter, in step S91, the server 2 calculates the EV travelable distance dEV based on the second EV travelable distance calculation method.

  FIG. 7 is a diagram showing in detail the processing for calculating the second EV travelable distance shown in FIG. 5 (processing executed in each of steps S91 to S93). Referring to FIG. 7, server 2 obtains the SOC after the end of external charging (step S911), and calculates EV travelable distance dEV from the SOC (step S912).

  The flowchart shown in FIG. 7 differs from the flowchart shown in FIG. 6 in that the correction coefficient k is not calculated (see steps S903 to S905 in FIG. 6). Since the correction coefficient k is not calculated, the correction coefficient k is not updated. The reason why the correction coefficient k is not updated will be described below.

  As described in step S904, the deteriorated battery capacity C1 is calculated using the SOC after the end of external charging. However, in step S911 shown in FIG. 7, since a predetermined time has not elapsed since the end of external charging, the SOC is calculated from the voltage VB before the polarization of the battery 50 is eliminated. That is, there is a possibility that an error due to the influence of polarization occurs in the SOC after the completion of the external charging calculated in step S911. Therefore, in the flowchart shown in FIG. 7, the battery capacity C1 cannot be obtained more accurately than in the flowchart shown in FIG. Therefore, in case 2, the correction coefficient k is not calculated and updated.

  Therefore, in step S913 in FIG. 7, the server 2 corrects the EV travelable distance dEV by multiplying the EV travelable distance dEV by the previous correction coefficient k stored in the memory. Furthermore, the server 2 transmits the corrected EV travelable distance dEV to the vehicle 1. The ECU 300 displays the EV travelable distance dEV from the server 2 on the monitor 42 (step S101 in FIG. 5). Thereby, the whole process shown in FIG. 5 is completed.

[Case 3]
Case 3 is a case where a certain period of time has not elapsed between the time of IG-OFF and the start of external charging. Case 3 includes a case where a certain time has elapsed from the end of external charging to the time of IG-ON and a case where the certain time has not elapsed.

  If period L1 is less than the threshold value in step S30 (NO in step S30), the process proceeds to steps S52, S62, and S82. Since the processes of steps S52, S62, and S82 are the same as the processes of steps S50, S60, and S80, detailed description thereof will not be repeated.

  Thereafter, in step S92, the server 2 calculates the EV travelable distance dEV based on the second EV travelable distance calculation method. That is, in case 3, as in case 2, the correction coefficient k is not updated. The reason will be described below.

  In Case 3, a certain time has not elapsed from the time of IG-OFF to the start of external charging. For this reason, polarization is not eliminated even just before the start of external charging, and an error due to polarization may occur. Therefore, in case 3, voltage VB immediately before external charging is not transmitted from ECU 300 to server 2. Therefore, in case 3, the correction coefficient k is not updated.

[Case 4]
Case 4 is a case in which external charging is not performed and a certain time has elapsed from the time of IG-OFF to the time of IG-ON.

  If external charging is not performed in step S20 (NO in step S20), the process proceeds to step S63. In step S63, the IG-ON operation is performed without external charging. Thereafter, the process proceeds to step S73.

  In step S73, the server 2 determines whether or not the period L3 is equal to or greater than a predetermined threshold value. If period L3 is equal to or greater than the threshold value (YES in step S73), the process proceeds to step S83. Since the process of step S83 is equivalent to the process of step S80, detailed description will not be repeated.

  Thereafter, in step S93, the server 2 calculates the EV travelable distance dEV based on the second EV travelable distance calculation method.

  Here, since external charging is not performed in Case 4, the SOC does not change between the time of IG-OFF and the time of IG-ON. Therefore, there is no need to update the EV travelable distance dEV, and it is considered that the EV travelable distance dEV calculated last time may be used as it is. However, in case 4, since the fixed time has elapsed from the time of IG-OFF to the time of IG-ON, the polarization of the battery 50 is eliminated. Therefore, in step S83, the SOC can be accurately estimated based on the voltage VB after depolarization. As a result, the calculation accuracy of the EV travelable distance dEV can be improved.

  On the other hand, in case 4, as in cases 2 and 3, the correction coefficient k is not updated. This is because the external charging is not performed in case 4, and thus the SOC immediately before the start of external charging cannot be calculated (see step S903).

[Case 5]
Case 5 is a case where external charging is not performed and a certain period of time has not elapsed between the time of IG-OFF and the time of IG-ON.

  If period L3 is less than the threshold value (NO in step S73), the process proceeds to step S104. In case 5, since external charging is not performed, the SOC does not change between the time of IG-OFF and the time of IG-ON. Moreover, in case 5, since the fixed time has not elapsed from the time of IG-OFF to the time of IG-ON, the polarization of the battery 50 is not eliminated. Therefore, in step S104, the ECU 300 causes the monitor 42 to display the EV travelable distance dEV calculated last time without updating the EV travelable distance dEV. In case 5, there is no need to communicate between ECU 300 and server 2.

  Although the vehicle 1 is described as a hybrid vehicle in the present embodiment, the vehicle 1 may be an electric vehicle that includes a motor generator as a power source and does not include an engine.

  In the present embodiment, it has been described that the SOC and EV travelable distance dEV are calculated by the server. However, either or both of the SOC and EV travelable distance dEV may be calculated by an ECU mounted on the vehicle.

  Furthermore, although the case of external charging has been described, the calculation accuracy of the EV travelable distance can be improved with the same configuration also in the case of supplying battery power outside the vehicle (external power feeding).

  Finally, this embodiment will be summarized with reference to FIGS. 1 to 3 again. The travelable distance calculation system calculates the travelable distance of the vehicle 1 including the second MG 102 and the battery 50 that can supply drive power to the second MG 102. The vehicle 1 has an IG-ON state in which traveling using the electric power of the battery 50 is permitted, and an IG-OFF state in which traveling using the electric power of the battery 50 is prohibited. External charging for charging the battery 50 with electric power supplied from the outside is possible. The travelable distance calculation system includes an SOC estimation unit 202 that estimates SOC from OCV according to an SOC-OCV curve indicating a relationship between SOC and OCV of battery 50, and EV travelable distance dEV that uses electric power of battery 50 from SOC. EV travelable distance calculating unit 206 that calculates the time, a period L1 from the time of IG-OFF to the start of external charging, and a period measurement unit 306 that measures a period of time L2 from the end of external charging to the time of IG-ON. With. EV travelable distance calculation unit 206 calculates EV travelable distance dEV from the SOC immediately before IG-ON at the time of IG-ON, and further corrects EV travelable distance dEV based on periods L1 and L2.

  Preferably, the SOC-OCV curve includes a charging side curve CHG indicating characteristics during charging of the battery 50 and a discharging side curve DCHG indicating characteristics during discharging of the battery 50. The SOC estimation unit 202 selects a corresponding curve from the charge side curve CHG and the discharge side curve DCHG depending on whether the battery 50 is being charged or discharged immediately before the transition to the IG-OFF state. Then, the SOC immediately before the start of external charging is estimated according to the selected curve. EV travelable distance calculation unit 206 corrects EV travelable distance dEV calculated after the transition to the IG-ON state based on the SOC immediately before the start of external charging.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 vehicle, 2 server, 10 driving force generator, 20 power supply system, 22g, 58g ground wiring, 22p, 58p power supply wiring, 24 charger, 26 charging connector, 40 ignition switch, 42 monitor, 50 battery, 52 voltage sensor, 54 Current sensor, 56 Temperature sensor, 60 Converter, 100 Engine, 101 1st MG, 102 2nd MG, 104 Power split device, 106 Drive wheel, 111, 112 Inverter, 202 SOC estimation unit, 204 Correction coefficient calculation unit, 206 Driven Distance calculation unit, 208, 310 communication unit, 302 charge / discharge state determination unit, 304 electricity quantity calculation unit, 306 period measurement unit, 308 vehicle specific information holding unit, 350 memory, 400 external power supply, 402 charge plug, RL1, RL2 relay , SMR1, SMR System main relay.

Claims (4)

A travelable distance calculation system for a vehicle comprising a rotating electrical machine and a power storage device capable of supplying driving power to the rotating electrical machine,
The vehicle has a first mode in which traveling using the power of the power storage device is permitted and a second mode in which traveling using the power of the power storage device is prohibited, and the second mode. Then, it is configured to allow external charging to charge the power storage device with electric power supplied from the outside of the vehicle,
The travelable distance calculation system includes:
An estimation unit that estimates the state of charge from the voltage according to a characteristic indicating a relationship between a state of charge of the power storage device and a voltage of the power storage device;
A calculation unit that calculates a travelable distance of the vehicle using the power of the power storage device from the charged state;
Measure a first period from the time of transition to the second mode to the start of the external charge and a second period from the end of the external charge to the time of transition to the first mode With a measuring unit,
The calculation unit includes:
At the time of transition to the first mode, the travelable distance is calculated from the state of charge immediately before transition to the first mode ,
When the first period exceeds the first threshold value and the second period exceeds the second threshold value, the charging state immediately before the start of the external charging and the Update the correction coefficient based on the charge state after the end of external charging, correct the travelable distance based on the updated correction coefficient,
When the first period exceeds the first threshold value and the second period falls below the second threshold value, based on the correction coefficient before the update, A travelable distance calculation system that corrects the travelable distance. The characteristics include a first characteristic when the power storage device is charged and a second characteristic when the power storage device is discharged,
The estimation unit corresponds to one of the first and second characteristics depending on whether the power storage device is being charged or discharged immediately before the vehicle shifts to the second mode. Select a characteristic, and in accordance with the selected characteristic, estimate a state of charge immediately before the start of the external charging,
The travelable distance calculation system according to claim 1, wherein the calculation unit corrects the travelable distance calculated at the time of shifting to the first mode based on a charging state immediately before the start of the external charging. The travel according to claim 1 or 2, wherein when the first period falls below the first threshold, the calculation unit corrects the travelable distance based on the correction coefficient before the update. Possible distance calculation system. When the external charging is not performed in the third period from the transition to the second mode to the transition to the first mode,
When the third period exceeds a third threshold, the travelable distance is corrected based on the correction coefficient before the update,
The travelable distance calculation system according to any one of claims 1 to 3, wherein the travelable distance is not corrected when the third period falls below the third threshold value.

Images