JP2018176820A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve fuel economy while protecting a battery in a hybrid vehicle incorporating a battery including a lithium ion secondary cell.SOLUTION: A vehicle 1 includes: an engine 50; a battery 100 including a lithium ion secondary cell; a gyro sensor 108 for detecting an inclination of the battery 100; a motor-generator 10 enabled for generation using power generated by the engine 50; and a PCU 200 for converting power between the battery 100 and motor-generator 10. An ECU 300 determines operation points of the engine 50 and motor-generator 10 so as to increase charging power for the battery 100 as a fuel usage efficiency E increases when charging the battery 100. In a case where an inclination θy of the battery 100 is larger than a given value, the ECU 300 calculates density distribution of lithium salt by using the inclination of the battery 100 and corrects the operation points on the basis of the calculated density distribution.SELECTED DRAWING: Figure 10

Description

  The present disclosure relates to a hybrid vehicle, and more particularly to a hybrid vehicle equipped with a battery including a lithium ion secondary battery.

  In recent years, the spread of hybrid vehicles has progressed. In hybrid vehicles, it is particularly required to improve fuel efficiency by efficiently using fuel. Therefore, a method for appropriately determining the operating state (operating point) of the engine and the motor has been proposed. For example, Japanese Patent Application Laid-Open No. 2001-298805 (Patent Document 1) determines operating points of an engine and a motor based on a vehicle speed, a driving force command value to a vehicle, and an efficiency index related to fuel utilization efficiency. Disclose a hybrid vehicle.

JP 2001-298805 A JP, 2013-071622, A

  There are commercially available hybrid vehicles in which lithium ion secondary batteries are mounted as running batteries. Generally, when charging / discharging at a large current (so-called high rate charging / discharging) is performed in a lithium ion secondary battery (hereinafter also referred to as "battery"), the concentration of lithium salt in the electrolyte (hereinafter referred to as "salt concentration" It is known that bias may occur. When the salt concentration is biased, the battery performance (charge / discharge performance) may be reduced due to the increase in the internal resistance of the battery. Generally, such degradation is also referred to as "high rate degradation".

  One of the causes of the occurrence of the deviation of the salt concentration due to the high rate charge / discharge is that the electrode body expands due to the high rate charge / discharge, which causes the deviation of the electrolyte solution inside the electrode body. The bias of the electrolyte solution generated by the high rate charge and discharge is alleviated with the passage of time after the high rate charge and discharge is completed. Along with this, the bias of salt concentration is gradually equalized.

  However, while the vehicle equipped with a battery is traveling on a slope or parked on a slope, the battery tilts. Depending on the size of the inclination, the electrolytic solution may be easily retained below the electrode assembly, but the electrolytic solution may be easily insufficient above the electrode assembly. As a result, as compared with the state in which the battery is horizontal, the bias of the electrolyte solution (and the bias of the salt concentration due to it) may be less likely to be made uniform.

  In the hybrid vehicle disclosed in Patent Document 1, although it is disclosed that fuel efficiency is improved by determining the operating point of the engine and the motor using the efficiency index, it is possible that the battery may be inclined due to road gradient or the like. No consideration is given to the impact on deterioration. For this reason, there is a possibility that the battery can not be protected properly.

  The present disclosure has been made to solve the above problems, and an object of the present disclosure is to properly protect a battery from high rate deterioration while improving fuel efficiency in a hybrid vehicle equipped with a battery including a lithium ion secondary battery. It is to be.

  A hybrid vehicle according to one aspect of the present disclosure uses an engine that generates power using fuel, a battery that includes a lithium ion secondary battery, a detection device that detects an inclination of the battery, and power generated by the engine. A rotating electrical machine configured to be capable of generating electric power, a power conversion device that performs power conversion between a battery and the rotating electrical machine, and a control device configured to control an engine and the power conversion device. The control device determines the operating state of the engine and the rotating electrical machine such that the charging power to the battery increases as the fuel utilization efficiency at the time of charging the battery increases. The controller calculates the concentration distribution of the lithium salt in the battery using the inclination of the battery when the inclination of the battery is larger than a predetermined value, and corrects the operating state according to the calculated concentration distribution.

  According to the above configuration, the operating state (operating point) of the engine and the rotating electrical machine is corrected in consideration of the concentration distribution of lithium salt (bias in the concentration of lithium salt) generated by the battery tilting. Therefore, it is possible to appropriately protect the battery while improving fuel efficiency using the utilization efficiency of the fuel.

  According to the present disclosure, in a hybrid vehicle equipped with a battery including a lithium ion secondary battery, the battery can be appropriately protected while improving fuel consumption.

FIG. 1 schematically shows an overall configuration of a hybrid vehicle according to an embodiment of the present disclosure. It is a figure which shows the structure of a battery in more detail. It is a figure for demonstrating the structure of each cell in more detail. It is a figure for demonstrating the determination method of the operating point in this Embodiment. It is a figure which shows the relationship of the operating point and the charging electric power to a battery in the same conditions as the example shown in FIG. It is a figure for demonstrating a mode that the bias of electrolyte solution arises according to the inclination of a battery. It is a figure which shows an example of the measurement result of the change rate of the internal resistance of the battery according to inclination (theta) x of the battery, and (theta) y. It is the figure which put together the measurement result shown to FIG. 7 (B). It is a flowchart for demonstrating the driving | operation point determination process in this Embodiment. It is a flowchart for demonstrating the inclination process (S113) shown in FIG.

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

Embodiment
<Overall Configuration of Hybrid Vehicle>
FIG. 1 schematically shows an overall configuration of a hybrid vehicle according to an embodiment of the present disclosure. Referring to FIG. 1, vehicle 1 is a hybrid vehicle, and includes motor generators 10 and 20, power split device 30, drive wheel 40, engine 50, and a power control unit (PCU) 200. , A system main relay (SMR), a battery 100, an electronic control unit (ECU: Electronic Control Unit) 300, and a navigation device 400.

  The engine 50 is an internal combustion engine that outputs motive power by converting combustion energy generated when a mixture of air and fuel is burned into kinetic energy of a moving element such as a piston or a rotor.

  Power split device 30 includes, for example, a planetary gear mechanism having three rotation shafts of a sun gear, a carrier, and a ring gear (none of which are shown). Power split device 30 splits the power output from engine 50 into power for driving motor generator 10 and power for driving drive wheels 40.

  Each of motor generators 10 and 20 is an AC rotating electric machine, and is, for example, a three-phase AC synchronous motor in which permanent magnets are embedded in a rotor.

  Motor generator 10 is mainly used as a generator driven by engine 50 via power split device 30. The electric power generated by motor generator 10 is supplied to motor generator 20 or battery 100 via PCU 200. The motor generator 10 corresponds to the "rotating electric machine" according to the present disclosure.

  The motor generator 20 mainly operates as an electric motor and drives the drive wheel 40. Motor generator 20 is driven by receiving at least one of the power from battery 100 and the generated power of motor generator 10, and the driving force of motor generator 20 is transmitted to the drive shaft. On the other hand, at the time of braking the vehicle or reducing the acceleration on the downward slope, the motor generator 20 operates as a generator to perform regenerative power generation. The electric power generated by motor generator 20 is supplied to battery 100 via PCU 200.

  PCU 200 executes bi-directional power conversion between battery 100 and motor generators 10, 20 in accordance with a control signal from ECU 300. PCU 200 is configured to be capable of separately controlling the states of motor generators 10 and 20. For example, motor generator 20 can be brought into a power running state while motor generator 10 is brought into a regeneration state (power generation state). PCU 200 includes, for example, two inverters provided corresponding to motor generators 10 and 20, and a converter (not shown) for boosting DC voltage supplied to each inverter to an output voltage of battery 100 or more. It consists of The PCU 200 corresponds to the “power conversion device” according to the present disclosure.

  SMR 150 is electrically connected between battery 100 and PCU 200. SMR 150 is opened / closed in response to a control signal from ECU 300. Thereby, conduction and interruption between battery 100 and PCU 200 are switched.

  Battery 100 is configured to include a plurality of cells 110 (see FIG. 2) each of which is a lithium ion secondary battery. Battery 100 stores power for driving motor generators 10 and 20, and supplies power to motor generators 10 and 20 through PCU 50. Further, battery 100 receives and generates electric power through PCU 200 when electric power is generated by motor generators 10 and 20.

  The battery 100 is provided with a voltage sensor 102, a current sensor 104, and a temperature sensor 106. Voltage sensor 102 detects voltages VB of a plurality of cells connected in parallel in battery 100. Current sensor 104 detects a current IB input / output to / from battery 100. The temperature sensor 106 detects the temperature TB for each cell. Each sensor outputs the detection result to the ECU 300. A plurality of temperature sensors 106 (number smaller than the number of cells) may be provided for the battery 100, and temperature may be detected using a plurality of (for example, several) adjacent cells as a monitoring unit.

  The battery 100 is further provided with a gyro sensor 108. For example, when the vehicle 1 is traveling on a slope or when the vehicle 1 is stopped on a slope, the vehicle 1 may tilt. The gyro sensor 108 detects the inclination θ of the battery 100 from the horizontal direction. More specifically, the gyro sensor 108 has an inclination θx in the short side direction (x axis direction) of the cell 110 (described later) with respect to the horizontal direction and an inclination θy in the long side direction (y axis direction) with respect to the horizontal direction. To detect both. The gyro sensor 108 outputs the detection result to the ECU 300. The installation location of the gyro sensor 108 is not limited to the battery 100, and may be installed at another location of the vehicle 1 (for example, a hill start assist system not shown). The gyro sensor 108 corresponds to the “detection device” according to the present disclosure.

  Navigation device 400 includes a GPS (Global Positioning System) receiver (not shown) for identifying the position of vehicle 1 based on radio waves from a satellite (not shown). The navigation device 400 executes various navigation processing of the vehicle 1 using the position information (GPS information) of the vehicle 1 specified by the GPS receiver. More specifically, the navigation device 400 superimposes the current position of the vehicle 1 on the road map around the vehicle 1 based on the GPS information of the vehicle 1 and the road map data stored in the memory (not shown). In addition, the navigation screen (not shown) is displayed. The navigation device 400 also guides a recommended route from the current value of the vehicle 1 to the destination using GPS information.

  The ECU 300 includes a central processing unit (CPU) 302, a memory (more specifically, a read only memory (ROM) and a random access memory (RAM)) 304, and an input / output port (not shown) for inputting and outputting various signals. And is included. ECU 300 controls engine 50 and PCU 200 based on the signals received from each sensor and the program and map stored in memory 304. Thereby, charge and discharge of the battery 100 are controlled.

  FIG. 2 shows the configuration of battery 100 in more detail. FIG. 3 is a diagram for explaining the configuration of each cell 110 in more detail. In FIGS. 2 and 3, it is assumed that the vehicle 1 is in a horizontal state (running on a flat ground or in a parked state).

  Referring to FIG. 2, battery 100 includes a plurality of cells 110, a pair of end plates 120, a restraining band 130, and a plurality of bus bars 140. In FIG. 2, one end of the stacking direction (x-axis direction) of the stacked body formed by stacking the plurality of cells 110 is partially shown. A pair of end plates 120 is disposed to face one end of the stack and the other end in the stacking direction. The pair of end plates 120 is restrained by the restraint band 130 with all the cells 110 sandwiched therebetween. Each cell 110 has a positive electrode terminal 113 and a negative electrode terminal 114 (see FIG. 3). The positive electrode terminal 113 of a certain cell and the negative electrode terminal 114 of the adjacent cell are fastened by the bus bar 140 and electrically connected. Thereby, a plurality of cells 110 are connected in series.

  Referring to FIG. 3, cell 110 is shown in FIG. 3 in a transparent manner. The cell 110 has a substantially rectangular battery case 111. The short side direction (thickness direction) of the battery case 111 is taken as the x-axis direction, the long side direction (longitudinal direction) is taken as the y-axis direction, and the height direction is taken as the z-axis direction. The vertical direction is the negative z-axis direction, and the horizontal direction is the xy plane direction.

  The top surface of the battery case 111 is sealed by a lid 112. One end of each of the positive electrode terminal 113 and the negative electrode terminal 114 protrudes from the lid 112 to the outside. The other ends of the positive electrode terminal 113 and the negative electrode terminal 114 are connected to the internal positive electrode terminal and the internal negative electrode terminal (both not shown) in the battery case 111. An electrode body 115 is accommodated in the battery case 111. The electrode body 115 is formed by laminating the positive electrode 116 and the negative electrode 117 with the separator 118 interposed therebetween, and winding the laminated body. The electrolytic solution is held by the positive electrode 116, the negative electrode 117, the separator 118, and the like.

For the positive electrode 116, the negative electrode 117, the separator 118, and the electrolytic solution, conventionally known configurations and materials can be used as a positive electrode, a negative electrode, a separator, and an electrolytic solution of a lithium ion secondary battery. As an example, the electrolytic solution includes an organic solvent (for example, a mixed solvent of DMC (dimethyl carbonate), EMC (ethyl methyl carbonate) and EC (ethylene carbonate)), a lithium salt (for example, LiPF ₆ ), an additive (for example, LiBOB (Lithium bis (oxalate) borate) or Li [PF ₂ (C ₂ O ₄ ) ₂ ]).

<Determination of operating point of engine and motor generator>
In the vehicle 1 configured as described above, the operating states of the engine 50 and the motor generator 10 are determined such that fuel consumption (= travel distance of the vehicle 1 / fuel consumption by the engine 50) is optimal. Hereinafter, the operating state of engine 50 and motor generator 10 will be referred to as “operating point”, and the method of determining the operating point will be described using FIGS. 4 and 5 (note that details of FIGS. 4 and 5 are patent) Reference 1).

  FIG. 4 is a diagram for explaining the method of determining the operating point in the present embodiment. In FIG. 4, the horizontal axis indicates the rotational speed of the engine 50 (engine rotational speed). The vertical axis represents the output torque (engine torque) from the engine 50.

  In FIG. 4, “contour lines” with equal fuel consumption are shown by thin solid lines. Further, when obtaining the same engine output, the “optimum fuel consumption line” in which the fuel consumption is minimized in consideration of the efficiencies of the engine 50 and the motor generator 10 is shown by a thick solid line. The operating point is determined on the optimal fuel consumption line. In FIG. 4, six operating points A, N, and B to E are illustrated on the optimum fuel consumption line.

  The driving point A drives the vehicle 1 by the motor generator 20 as much as possible (for example, the maximum power that can be discharged from the battery 100 is supplied to the motor generator 20 to drive the vehicle 1), and It is an operating point when it is covered by the output of.

  From the operating point A to the operating point E via the operating point N, the amount of fuel supplied to the engine 50 increases, and accordingly the discharge power from the battery 100 decreases, while the charge power to the battery 100 is large. Become. The operating point N is an operating point at which the charge / discharge power (charge power and discharge power) of the battery 100 becomes zero. Then, the charging power to the battery 100 increases in the order of B-C-D-E. The operating point E is an operating point in the case where the vehicle 50 is driven by the engine 50 and power generated by the motor generator 10 is generated by using the power of the engine 50 in order to increase charging power to the battery 100 as much as possible. .

  On the optimum fuel consumption line, the operating point is determined based on “fuel utilization efficiency E” that indicates the utilization efficiency of fuel by engine 50 when charging battery 100. The fuel utilization efficiency E can be determined, for example, as follows. That is, first, when the user operates navigation device 400 to input the destination of vehicle 1, the target value (target SOC) of the SOC of battery 100 at the destination is set (calculated). The target value of the SOC may be a predetermined fixed value or, for example, a variable value determined according to the destination.

  For example, if the operating point is determined such that the battery 100 is charged only when the fuel utilization efficiency E is relatively high, the actual SOC at the destination becomes relatively low because the charging opportunity of the battery 100 is reduced. Conversely, if the operating point is determined such that the battery 100 is charged even if the fuel utilization efficiency E is low to some extent, the actual SOC at the destination becomes relatively high as the charging opportunity of the battery 100 increases. Therefore, a temporary value is set for the fuel utilization efficiency E, and a change in SOC in the traveling route to the destination is predicted, and the predicted value of SOC at the destination is compared with the target value of SOC. If the predicted value of SOC at the destination is higher than the target value, the fuel utilization efficiency E is decreased from the previous value, and the predicted value of SOC is recalculated. On the other hand, when the predicted value of SOC at the destination is higher than the target value, the fuel utilization efficiency E is increased from the previous value, and the predicted value of SOC is recalculated. Then, the calculation of the fuel utilization efficiency E is repeated until the predicted value of the SOC at the destination matches the target value (until the difference between the two becomes smaller than a predetermined value). The fuel use efficiency E when the predicted value of the SOC matches the target value is adopted (see Patent Document 1 for details). The operating point is determined as follows using the fuel utilization efficiency E calculated in this way.

  FIG. 5 is a diagram showing the relationship between the operating point and the charging power to the battery 100 under the same conditions as the example shown in FIG. In FIG. 5, the horizontal axis indicates an increase (fuel increase) Δfuel of the fuel supply based on the fuel supply at the operating point A.

  The vertical axis in the lower part of FIG. 5 represents the amount of increase (power difference) Δbat of the charging power to battery 100 or the charging power to battery 100 based on the discharging power from battery 100 at operating point A. Curve L1 shows the relationship between the amount of increase in fuel Δfuel and the charging power to battery 100.

  The vertical axis in the upper part of FIG. 5 indicates the fuel utilization efficiency E which is the ratio of the fuel increase amount Δfuel to the charge power increase amount Δbat (= ΔΔfuel / bat). Further, the curve L2 shows the relationship between the fuel increase amount Δfuel and the fuel utilization efficiency E in the curve L1. The curves L1 and L2 can be obtained in advance by experiment for each combination condition of the vehicle speed V and the driving force.

  First, the fuel utilization efficiency E is calculated by repeating the above recalculation. Then, the operating point is determined from the calculated fuel utilization efficiency E. In the example shown in FIG. 5, for example, when a certain fuel utilization efficiency E is determined as B ′ on the curve L2, a point B on the curve L1 corresponding to B ′ is determined as the operating point . Similarly, when the fuel utilization efficiency E is determined as C 'on the curve L2, a point C on the curve L1 corresponding to C' is determined as the operating point. The same applies to the other fuel utilization efficiency E.

  By determining the operating point by such a method, engine 50 is driven in a state of high fuel consumption (driven on the optimal fuel consumption line), and charge power to battery 100 according to fuel utilization efficiency E is determined. be able to.

<Slope of battery>
Here, when the vehicle 1 is traveling on a slope, for example, or when the vehicle 1 is parked on a slope, inclinations θx and θy occur in the battery 100. As described above, the inclination θx indicates the inclination in the short side direction (x-axis direction) of the cell 110 with respect to the horizontal direction, and the inclination θy is the long side direction (y-axis direction) of the cell 110 with respect to the horizontal direction. . Depending on the inclinations θx and θy, the electrolytic solution in the electrode body 115 may be biased, or the bias once generated may be alleviated.

  FIG. 6 is a diagram for explaining how the electrolyte solution is biased according to the inclination of the battery 100. As shown in FIG. FIG. 6 and FIG. 7 described later schematically show the case where one of the plurality of cells 110 constituting the battery 100 is horizontally installed and the case where the inclination θy occurs.

  When the battery 100 is installed horizontally as shown in FIG. 6A, the inflow and the outflow of the electrolyte occur equally between the left side and the right side of the electrode body 115 (indicated by a broken line) in the drawing.

  On the other hand, when the battery 100 is inclined by θy as shown in FIG. 6B, the outflow amount of the electrolyte on the left side of the electrode body 115 is the outflow amount of the electrolyte on the right side in the drawing. It can be bigger than that. Further, on the left side of the electrode body 115 in the drawing, the inflow of the electrolytic solution to the electrode body 115 may be less likely to occur than in the right side of the drawing. As a result, when the battery 100 is inclined, the bias of the lithium salt is less likely to be alleviated as compared with the case where the battery 100 is horizontal.

  As described above, depending on the inclinations θx and θy of the battery 100, the electrolyte tends to stay below the electrode body 115 (in the negative z-axis direction), while the electrolyte tends to run short above the electrode body 115. Situations can arise. Thereby, the equalization of the bias of the electrolytic solution is prevented in comparison with the state where the battery 100 is installed horizontally. As a result, there is a possibility that the relaxation rate of the deviation of the salt concentration caused by the high rate deterioration may be slowed (the amount of relaxation per unit time is decreased).

  FIG. 7 is a diagram showing an example of the measurement results of the rate of change of the internal resistance of battery 100 according to the inclinations θx and θy of battery 100. The battery 100 was installed in each state shown in (a) to (f) of FIG. 7A, and the internal resistance of the battery 100 was measured each time a predetermined period passed. The measurement results are shown in FIG. 7 (B). In FIG. 7B, the horizontal axis indicates the elapsed time from the initial state (for example, the state immediately after manufacture), and the vertical axis indicates the rate of change in internal resistance of battery 100 (hereinafter abbreviated as "rate of change in resistance"). Indicates The rate of change in resistance means the ratio of the internal resistance after the evaluation test to the internal resistance in the initial state.

  Referring to FIG. 7A, the state (a) is a state where the inclination θx = 0 ° and the inclination θy = 90 °. The state (b) is a state in which the inclination θx = 0 ° and the inclination θy = −90 °. The state (c) is a state where the inclination θx = 0 ° and the inclination θy = 45 °. The state (d) is a state where the inclination θx = 0 ° and the inclination θy = -45 °. State (e) is the state of slope θx = θy = 0 °, ie the state for the control measurement. The state (f) is a state in which the inclination θx = 90 ° and the inclination θy = 0 °. In addition, various well-known methods are employable as a measuring method of internal resistance.

  Referring to FIG. 7 (B), the rate of change in resistance in states (a) and (b) is the largest, and then the rate of change in resistance in states (c) and (d) is large, the state (f) resistance The rate of change is relatively small. In addition, it is understood that the rate of change in resistance in the state (e) for the control measurement (state in which the inclination θx = θy = 0 °) is the smallest. Also, it can be seen that the influence of the inclination θx is relatively small.

  FIG. 8 is a diagram summarizing the measurement results shown in FIG. 7 (B). In FIG. 8, the horizontal axis represents the inclination θy in the long side direction. The inclination θx in the short side direction is 0 °. The ordinate represents the rate of change in resistance after a predetermined period (several months) has elapsed since the initial state, based on the internal resistance in the state (e) in the initial state. Referring to FIG. 8, it can be seen that the rate of change in resistance increases as the gradient θy in the long side direction increases. Therefore, in the following, the case where the inclination θy changes will be described representatively. However, the inclination θx may be taken into consideration in addition to the inclination θy.

<Operation point determination process>
FIG. 9 is a flowchart for explaining the operating point determination process in the present embodiment. The process shown in this flowchart is called from the main routine and executed each time a predetermined condition is satisfied or a predetermined cycle elapses. Although each step (hereinafter abbreviated as "S") included in the flowchart of FIG. 9 and the flowchart of FIG. 10 described later is basically realized by software processing by ECU 300, dedicated hardware manufactured in ECU 300 (Electrical circuit) may be realized.

  Referring to FIGS. 1 and 9, ECU 300 acquires the current location of vehicle 1 from navigation device 400 in S101. Further, ECU 300 estimates the current SOC of battery 100. A known method can be used as the SOC estimation method.

  In S102, the ECU 300 determines whether the user has set or changed the destination. The setting (changing) of the destination may include the change of the recommended route due to the vehicle 1 deviating from the conventional recommended route or the change of the road condition. If there is setting (change) of the destination (YES in S102), the ECU 300 advances the process to S103. On the other hand, when there is no setting (change) of the destination (NO in S102), the ECU 300 skips the processing of S103 to S107 described below, and advances the processing to S108.

  In S103, the ECU 300 acquires the search result of the recommended route to the destination from the navigation device 400. Further, the ECU 300 virtually divides the recommended route to the destination into n (n is a natural number of 2 or more) segments. Examples of this division method include a method of dividing a point having a feature on a route as a division point, and a method of equally dividing a distance to a destination into n. The ECU 300 acquires, from the navigation device 400, the road environment such as the average slope, the curvature radius, and the altitude in each section. The information on the road environment may be acquired by communication with another vehicle (so-called inter-vehicle communication).

  In S104, the ECU 300 sets (calculates) a target value (target SOC) of the SOC at the destination based on the road environment of each section.

  In S105, the ECU 300 predicts the vehicle speed V and the driving force command value in each section based on the road environment of each section. The vehicle speed V of each section is, for example, basically using the speed limit of the road, while considering the deceleration accompanying the right turn / left turn at the intersection where the right turn / left turn, acceleration / deceleration according to the curvature of the road Can be predicted by taking account of The driving force command value of each section is, for example, a driving force for traveling resistance (air resistance + rolling resistance) according to the vehicle speed V, and an acceleration / deceleration for driving speed according to the speed difference from the previous section, It can be predicted from the driving force for acceleration and deceleration according to the road slope (see Patent Document 1 for details).

  In S106, the ECU 300 calculates the fuel utilization efficiency E. The method of calculating the fuel utilization efficiency E has been described in detail in FIG. 4 and FIG. 5, so the description will not be repeated.

  In S107, the ECU 300 predicts the SOC of each section based on the fuel utilization efficiency E calculated in S106 and the vehicle speed V and the driving force command value P * in each section predicted in S105. More specifically, as described above, by obtaining the operating point in each section based on the predicted value of fuel utilization efficiency E and vehicle speed V and the predicted value of driving force command value P *, charging of battery 100 in each section is completed. Discharge power can be calculated. Therefore, SOC in each section can be predicted by temporally integrating charge / discharge power in each section with the current SOC (the value estimated in S101) as an initial value.

  In S108, the ECU 300 acquires the current vehicle speed V from a vehicle speed sensor (not shown).

  In S109, the ECU 300 calculates the driving force command value P * from the vehicle speed V acquired in S108 and the accelerator opening Acc acquired by the accelerator sensor (not shown). More specifically, for example, by referring to a table of driving force command values set in advance, it is possible to calculate the driving force command value P * corresponding to the vehicle speed V and the accelerator opening Acc.

  In S110, ECU 300 estimates an error between the actual vehicle speed V (measured value) of each section and the predicted value of vehicle speed V in each section, and predicts actual driving force command value P * and driving force command value P *. It is determined whether the error from the value is larger than each predetermined value. As a method of calculating these errors, for example, the method described in Patent Document 1 can be used. If the error of at least one of vehicle speed V and driving force command value P * is larger than the predetermined value (YES in S110), ECU 300 returns the process to S105. If both errors are equal to or less than the predetermined value (NO in S110), the ECU 300 advances the process to S111.

  In S111, the ECU 300 determines whether the error between the current SOC and the predicted SOC is larger than a predetermined value in each section. If the error of SOC is larger than the predetermined value (YES in S111), ECU 300 returns the process to S106. If the prediction error is less than or equal to the predetermined value (NO in S111), the ECU 300 advances the process to S112.

  In S112, the ECU 300 determines the operating point based on the fuel utilization efficiency E, the current vehicle speed V, and the driving force command value P *. The determination method is described in detail in FIG. 4 and FIG. 5, so the description will not be repeated.

  Furthermore, in S113, the ECU 300 executes “tilting processing” to take into consideration the tilt of the battery 100.

  FIG. 10 is a flowchart for explaining the tilt processing (S113) shown in FIG.

  1 and 10, in S201, ECU 300 obtains inclination θy of battery 100 from gyro sensor 108.

  In S202, the ECU 300 determines whether the inclination θy acquired in S201 is larger than a predetermined value. The predetermined value is a value that can not ignore the influence of the inclination θy, and can be obtained in advance by experiment or simulation. If inclination θy is larger than the predetermined value (YES in S202), ECU 300 advances the process to S203.

  In S203, ECU 300 calculates the concentration distribution of the lithium salt in battery 100, for example, by executing a simulation based on fluid dynamics. A known method can be used for this simulation, and thus the detailed description will not be repeated (see, for example, JP-A-2017-168211).

  In S204, the ECU 300 reflects the inclination θy acquired in S201 in the calculation result of the concentration distribution of the lithium salt in S203. For example, correction coefficients corresponding to various inclinations θy can be set based on the measurement results as shown in FIG. 8, and the calculation results of the concentration distribution of lithium salt can be corrected using the correction coefficients.

  In S205, the ECU 300 limits the charge / discharge power of the battery 100 according to the calculation result (correction result) of the concentration distribution of the lithium salt in which the influence of the inclination θy is reflected in S204. More specifically, for example, charging power upper limit value Win indicating a control upper limit value of charging power to battery 100 is set lower as the concentration distribution of the lithium salt is more unevenly distributed. This setting can be realized, for example, by preparing in advance, as a map, a correspondence between an index value indicating deviation of concentration distribution of lithium salt and charging power upper limit value Win.

  In S206, the ECU 300 again determines (corrects) the operating point so that charging / discharging of battery 100 is performed within the range of the charging / discharging power (particularly charging power) calculated in S205. More specifically, as one example, when the charging power upper limit Wint is set to be lower than the normal time in S205, the operating point is set so that the charging power to the battery 100 does not exceed the charging power upper limit Win. decide. For example, in the example shown in FIG. 4, the operating point is normally determined on the optimum fuel consumption line between N and E, but is optimal when the charging power upper limit Wint is set lower than the normal time. The range of the operating point is limited to the range between N and C on the fuel efficiency line.

  If the inclination θy is equal to or less than the predetermined value in S203 (NO in S202), the processing in S204 to S206 is skipped, and the processing is returned to the flowchart shown in FIG. Further, although not shown, the ECU 300 controls the torque of the engine 50 and the torque of the motor generators 10, 20 such that the operating point determined in S206 (or S112 in FIG. 9) is realized.

  As described above, according to the present embodiment, in consideration of inclinations θx and θy of battery 100 (in particular, concentration distribution of lithium salt (bias in concentration of lithium salt) generated by θy), engine 50 and motor generator 10 Accordingly, the fuel use efficiency E can be used to improve the fuel efficiency, and the battery 100 can be appropriately protected.

  It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present disclosure is indicated not by the description of the embodiments described above but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

  Reference Signs List 1 vehicle, 10, 20 motor generator, 30 power split device, 40 drive wheels, 50 engines, 100 batteries, 102 voltage sensors, 104 current sensors, 106 temperature sensors, 108 gyro sensors, 110 cells, 111 battery cases, 112 lids 113 positive electrode terminal 114 negative electrode terminal 115 electrode body 116 positive electrode 117 negative electrode 118 separator 118 end plate 130 restraint band 140 bus bar 150 SMR 200 PCU 300 ECU 302 CPU 304 memory 400 navigation apparatus.

Claims (1)

An engine that generates power using fuel;
A battery including a lithium ion secondary battery,
A detection device for detecting the inclination of the battery;
A rotating electrical machine configured to be capable of generating power using power generated by the engine;
A power converter for performing power conversion between the battery and the rotating electrical machine;
The operating state of the engine and the rotary electric machine is configured to be configured to be able to control the engine and the power conversion device, and the charging power to the battery increases as the utilization efficiency of the fuel at the time of charging the battery increases. Control device to determine
The controller calculates the concentration distribution of lithium salt in the battery using the inclination of the battery when the inclination of the battery is larger than a predetermined value, and the operating state is calculated according to the calculated concentration distribution. A hybrid vehicle that corrects.

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