Hybrid Vehicles

Abstract

To provide a hybrid vehicle, which can suppress a rate at which exhaust gas is purified from decreasing, when staring a trip.SOLUTION: When stopping a hybrid system, an engine is operated to charge a power storage device (S13) when SOC of the power storage device is smaller than a lower limit value Sl at the time when the vehicle starts to travel (negative determination at S10), and the engine is stopped (positive determination at S10) when the SOC is above the lower limit value Sl at the time when the vehicle starts to travel. The lower limit value Sl at the time when the vehicle starts to travel shows amounts of electric power stored in the power storage device, which can be distributed to an electric heater until a temperature of an SCR catalyst reaches an active temperature and enable a hybrid vehicle to travel in an EV travel mode.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a hybrid vehicle, and more particularly to a hybrid vehicle equipped with an electrically heated catalyst as a catalyst for purifying exhaust gas from an internal combustion engine. [Background technology]

[0002] In a hybrid vehicle equipped with an internal combustion engine and a driving motor, an electrically heated catalyst is known as a catalyst for purifying the exhaust gas from the internal combustion engine. For example, Japanese Patent Application Laid-Open No. 2014-8914 (Patent Document 1) discloses a technology that can ensure the electric power required to start the internal combustion engine and start the internal combustion engine normally even if a request to start the internal combustion engine occurs during the energization and heating of the electrically heated catalyst. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-8914 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an internal combustion engine equipped with an electrically heated catalyst, the exhaust purification rate can be increased by passing current through the electrically heated catalyst before starting the internal combustion engine, and starting the internal combustion engine after the temperature of the electrically heated catalyst has reached its activation temperature and the warm-up of the electrically heated catalyst has been completed. When the power for the electrically heated catalyst is supplied by the power of the battery used for driving, the power stored in the battery is consumed by the electrically heated catalyst and the motor for driving.

[0005] When the hybrid vehicle system is stopped and the time until the next trip (system startup) is long, the temperature of the electrically heated catalyst drops to the outside air temperature, so that at the start of the next trip, more power is required to warm up the electrically heated catalyst, and the time until the warm-up of the electrically heated catalyst is completed is longer. Therefore, the power consumed by the driving motor until the warm-up of the electrically heated catalyst is completed also increases. Therefore, in order to increase the purification rate of the exhaust gas, if the electrically heated catalyst is energized before the start of the internal combustion engine at the start of the trip, and the internal combustion engine is started after the temperature of the electrically heated catalyst reaches the activation temperature and the warm-up of the electrically heated catalyst is completed, a lot of power is consumed. Therefore, if the amount of stored electricity in the electricity storage device is small, the amount of stored electricity in the electricity storage device may decrease before the warm-up of the electrically heated catalyst is completed, and the internal combustion engine may be started to generate electricity, which may cause a decrease in the purification rate of the exhaust gas.

[0006] An object of the present disclosure is to suppress a decrease in the exhaust purification rate at the start of a trip in a hybrid vehicle. [Means for solving the problem]

[0007] The hybrid vehicle disclosed herein is a hybrid vehicle that includes a hybrid system including a traction motor, a power storage device that supplies power to the traction motor, a generator that is driven by an internal combustion engine and generates power to be supplied to the power storage device, and a control device, and is capable of EV driving by running on the power of the traction motor with the internal combustion engine stopped. The internal combustion engine includes an electrically heated catalyst that can be heated by the power of the power storage device, and the control device is configured to operate the internal combustion engine until the SOC becomes equal to or greater than the predetermined value to charge the power storage device when the hybrid system is stopped and then stop the internal combustion engine if the SOC of the power storage device falls below a predetermined value when the hybrid system is stopped. The predetermined value is an SOC that allows the electrically heated catalyst to be heated until the temperature of the electrically heated catalyst reaches an activation temperature when the hybrid system is started and allows EV driving.

[0008] According to this configuration, the hybrid vehicle is capable of EV driving, running on the power of the traction motor with the internal combustion engine stopped. If the SOC of the power storage device falls below a predetermined value when the hybrid system is stopped, the control device operates the internal combustion engine until the SOC reaches or exceeds the predetermined value to charge the power storage device, and then stops the internal combustion engine. The predetermined value is an SOC that heats the electrically heated catalyst until the temperature of the electrically heated catalyst reaches its activation temperature when the hybrid system is started, and allows EV driving. The SOC (State Of Charge) of the power storage device is a value that indicates the amount of electricity stored in the power storage device, and is expressed, for example, as a percentage of the current amount of electricity stored in the power storage device relative to the full charge capacity of the power storage device.

[0009] Therefore, when the hybrid system is started at the start of a trip, the SOC of the power storage device is at a value (amount of stored electricity) that allows the electrically heated catalyst to be heated until its temperature reaches its activation temperature and enables EV driving, so that after the temperature of the electrically heated catalyst reaches its activation temperature and warm-up of the electrically heated catalyst is completed, the internal combustion engine can be started and a decrease in the exhaust purification rate can be suppressed.

[0010] Preferably, the predetermined value may be set based on a parameter representing the outside air temperature at the time of start-up of the hybrid system.

[0011] The temperature of the electrically heated catalyst at the start of the hybrid system is affected by the outside air temperature. For example, the lower the outside air temperature, the lower the temperature of the electrically heated catalyst, and the more power is required to warm up the electrically heated catalyst and the longer it takes to complete the warm-up of the electrically heated catalyst. With this configuration, the SOC that heats the electrically heated catalyst until the temperature of the electrically heated catalyst reaches its activation temperature at the start of the hybrid system and enables EV driving is set based on a parameter that represents the outside air temperature at the start of the hybrid system, so that it can be set relatively accurately.

[0012] Preferably, the predetermined value may be calculated by heating the electrically heated catalyst until the temperature of the electrically heated catalyst reaches an activation temperature when the hybrid system is started, and by learning the amount of electricity discharged from the power storage device when EV driving is performed.

[0013] The temperature of the electrically heated catalyst at the start of the hybrid system is affected by the outside air temperature, which changes depending on the environment (season, climate, region, etc.) in which the hybrid vehicle is placed. In addition, the driving pattern (power consumption) during EV driving while the electrically heated catalyst is warming up differs depending on the user of the hybrid vehicle. According to this configuration, the SOC at which the electrically heated catalyst is heated until it reaches its activation temperature at the start of the hybrid system and EV driving is possible is calculated by learning the amount of power discharged from the power storage device when the electrically heated catalyst is heated until it reaches its activation temperature at the start of the hybrid system and EV driving is performed, so that it can be calculated taking into account the environment in which the hybrid vehicle is placed and the driving characteristics of the user.

[0014] Preferably, the control device may be configured to heat the electrically heated catalyst when the hybrid system is started, and when the SOC of the power storage device falls below a lower limit while the vehicle is running in EV mode, to start the internal combustion engine, generate electricity using the generator, and charge the power storage device.

[0015] According to this configuration, if the amount of power consumed by EV driving becomes greater than initially expected, and the SOC of the power storage device drops to the lower limit before the warm-up of the electrically heated catalyst is completed, the internal combustion engine is started to generate electricity using the generator, and the power storage device is charged. This makes it possible to prevent the power storage device from deteriorating.

[0016] Preferably, the control device may be configured to heat the electrically heated catalyst when the hybrid system is started up until the temperature of the electrically heated catalyst reaches an activation temperature, and to limit the output of the traction electric motor when EV driving is performed.

[0017] According to this configuration, the power consumed by the traction motor during EV driving can be limited, thereby preventing the SOC of the power storage device from dropping to the lower limit before the warm-up of the electrically heated catalyst is completed.

[0018] Preferably, the control device may be configured to limit the output of the traction electric motor when the SOC of the power storage device becomes equal to or lower than an output limit threshold.

[0019] According to this configuration, the output of the driving motor is not limited until the SOC of the power storage device falls to the output limit threshold, so that good drivability can be ensured until the SOC of the power storage device falls to the output limit threshold.

[0020] Preferably, the internal combustion engine is equipped with an electric supercharger driven by power from the power storage device, and the control device may be configured to heat the electrically heated catalyst until the temperature of the electrically heated catalyst reaches an activation temperature when the hybrid system is started, and to drive the electric supercharger when EV driving is performed.

[0021] According to this configuration, when the electric supercharger is driven, air heated by electricity flows through the electrically heated catalyst, thereby facilitating the warming up of the electrically heated catalyst.

[0022] Preferably, the internal combustion engine is provided with an air pump that supplies air to the exhaust passage upstream of the electrically heated catalyst, and the control device may be configured to heat the electrically heated catalyst until the temperature of the electrically heated catalyst reaches an activation temperature when the hybrid system is started, and to drive the air pump when EV driving is performed.

[0023] According to this configuration, when the air pump is driven, air heated by electricity flows through the electrically heated catalyst, thereby accelerating the warming up of the electrically heated catalyst.

[0024] Preferably, the control device may further include an alarm device, and the control device may be configured to, when the hybrid system is stopped and the internal combustion engine is operated until the SOC of the power storage device reaches or exceeds a predetermined value, notify the user by the alarm device that the internal combustion engine is operating.

[0025] According to this configuration, even if the internal combustion engine is operating after the hybrid system has been stopped, it is possible to inform the driver that the operation is normal (not abnormal). Effect of the Invention

[0026] According to the present disclosure, in a hybrid vehicle, a decrease in the purification rate of exhaust gas can be suppressed at the start of a trip. [Brief description of the drawings]

[0027] [Figure 1] 1 is an overall configuration diagram of a hybrid vehicle V according to an embodiment of the present invention. [Diagram 2] FIG. 1 is a schematic configuration diagram of an engine 1. [Diagram 3] 13A and 13B are diagrams showing transitions in temperature and SCO of the SCR catalyst 74 when the SOC is low at the start of a trip during startup control. [Figure 4] 13A and 13B are diagrams showing transitions in temperature and SCO of the SCR catalyst 74 when the SOC at the start of a trip is high during startup control. [Diagram 5] 4 is a schematic flowchart illustrating a process of stop-time SOC control executed by the HV-ECU 100. [Figure 6] 4 is a schematic flowchart of a process for calculating a lower limit value Sl at the start of traveling, which is executed by the HV-ECU 100. [Figure 7] FIG. 4 is a diagram illustrating a transition of SOC during stop-time SOC control. [Figure 8] 4 is a schematic flowchart illustrating a startup control process executed by the HV-ECU 100. [Figure 9]10 is a schematic flowchart illustrating a startup control process executed by an HV-ECU in a second modification. [Figure 10] 13 is a schematic flowchart illustrating a startup control process executed by HV-ECU 100 in Modification 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and the description thereof will not be repeated.

[0029] 1 is an overall configuration diagram of a hybrid vehicle V according to this embodiment. The hybrid vehicle V is equipped with a hybrid system H including an engine 1, a first motor generator (hereinafter referred to as the “first MG”) 2, a second motor generator (hereinafter referred to as the “second MG”) 3, a power storage device 7, and an HV-ECU (Electronic Control Unit) 100.

[0030] The engine 1 is a compression ignition type internal combustion engine (diesel engine) equipped with an exhaust purification device, the details of which will be described later. The first MG 2 and the second MG 3 are AC rotating electric machines, for example, three-phase AC synchronous motors with permanent magnets embedded in the rotor.

[0031] The hybrid vehicle V is a series hybrid vehicle, and the first MG2 is used as a generator driven by the engine 1. AC power generated by the first MG2 is converted to DC power by the first inverter 4 and supplied to the power storage device 7 via the boost converter 6 to charge the power storage device 7. At this time, the boost converter 6 operates as a step-down circuit. In addition, the power generated by the first MG2 is supplied to the second MG3 via the second inverter 5. The first inverter 4 may convert the DC power supplied from the power storage device 7 into AC power for driving the first MG2, and the engine 1 may be cranked or motored using the first MG2.

[0032] The second MG3 mainly operates as an electric motor and drives the drive wheels 8. The second MG3 corresponds to the "driving electric motor" of the present disclosure. The second MG3 is driven by at least one of the electric power from the power storage device 7 and the electric power generated by the first MG2, and the drive force of the second MG3 is transmitted to the drive wheels 8. On the other hand, when the hybrid vehicle V is braking or going downhill, the second MG3 operates as a generator and performs regenerative power generation. The electric power generated by the second MG3 is charged to the power storage device 7 via the second inverter 5. The second inverter 5 also converts the DC power of the power storage device 7, boosted by the boost converter 6, into AC power for driving the second MG3.

[0033] The power storage device 7 is a rechargeable DC power source, and includes a secondary battery such as a lithium ion battery or a nickel metal hydride battery. The power storage device 7 is charged by receiving electric power generated by at least one of the first MG 2 and the second MG 3. The power storage device 7 then supplies the stored electric power to the second inverter 5 and the first inverter 4. Note that an electric double layer capacitor or the like can also be used as the power storage device 7.

[0034] The power storage device 7 is provided with a monitoring unit 7a. The monitoring unit 7a includes a voltage sensor, a current sensor, and a temperature sensor (none of which are shown) that respectively detect the voltage, input / output current, and temperature of the power storage device 7. The monitoring unit 7a outputs the detection values ​​of each sensor (the voltage, input / output current, and temperature of the power storage device 7) to the BAT-ECU 110.

[0035] The step-down converter 9 steps down the DC power of the power storage device 7 and supplies the power to an electric supercharger 30 and an electric heater 78, which will be described later.

[0036] The hybrid vehicle V further includes a BAT-ECU 110, various sensors 120, a communication device 130, a navigation device 140, an HMI (Human Machine Interface) device 150, and an E / G-ECU 200. The HV-ECU 100, the BAT-ECU 110, and the E / G-ECU 200 are configured to be able to communicate with each other via a CAN (Controller Area Network) 150.

[0037] The HV-ECU 100 as a control device includes a CPU (Central Processing Unit), a ROM (Read Only Memory) for storing processing programs and the like, a RAM (Random Access Memory) for temporarily storing data, an input / output port (not shown) for inputting and outputting various signals, and executes a predetermined arithmetic processing based on information stored in the memory (ROM and RAM), information from various sensors 120, and information from the BAT-ECU 110 and the E / G-ECU 200. Then, the HV-ECU 100 controls the first inverter 4, the second inverter 5, and the boost converter 6 based on the results of the arithmetic processing, and outputs commands to the E / G-ECU 200.

[0038] When the power switch (ignition switch) 121 is operated while the hybrid system H is stopped, the HV-ECU 100 starts the hybrid system H and makes the hybrid vehicle V ready to run. Also, when the power switch 121 is operated while the hybrid system H is operating (started), the HV-ECU 100 stops the hybrid system H. This brings the hybrid vehicle V into a stopped state in preparation for the next trip.

[0039] The BAT-ECU 110 also includes a CPU, a ROM, a RAM, input / output ports, etc. (none of which are shown). The BAT-ECU 110 calculates the SOC, which indicates the amount of electricity stored in the power storage device 7, based on the detection values ​​of the input / output current and / or voltage of the power storage device 7 from the monitoring unit 7a. The SOC is expressed as a percentage of the current amount of electricity stored in the power storage device 7 relative to the full charge capacity of the power storage device 7. The BAT-ECU 110 then outputs the calculated SOC to the HV-ECU 100. The SOC may be calculated in the HV-ECU 100.

[0040] The various sensors 120 include, for example, an accelerator pedal sensor, an engine speed sensor, a vehicle speed sensor, an outside air temperature sensor, a catalyst temperature sensor, and the like. The accelerator pedal sensor detects the amount of accelerator pedal operation by the user (hereinafter also referred to as "accelerator opening") AP. The engine speed sensor detects the rotation speed (revolutions) NE of the engine 1. The vehicle speed sensor detects the speed (vehicle speed) SPD of the hybrid vehicle V. The outside air temperature sensor detects the outside air temperature. The catalyst temperature sensor 122 (see FIG. 2) detects the temperature of a selective reduction catalyst, which will be described later.

[0041] The communication device 130 is configured to include various communication I / Fs (interfaces). The communication device 130 may include a DCM (Data Communication Module). The communication device 130 may include a communication I / F compatible with 5G (fifth generation mobile communication system). The HV-ECU 100 is configured to perform wireless communication with a communication device outside the hybrid vehicle V through the communication device 130.

[0042] The navigation device 140 includes a navigation ECU, a map information database (DB), a GPS (Global Positioning System) receiving unit, and a traffic information receiving unit, all of which are not shown. The navigation ECU includes a CPU, a ROM, a RAM, an input / output port, and the like, and outputs the current position of the hybrid vehicle V, as well as surrounding map information and traffic congestion information, and the like, to the HV-ECU 100 and the HMI device 150 based on various information and signals received from the map information DB, the GPS receiving unit, and the traffic information receiving unit.

[0043] The HMI device 150 is a device that provides the user with information to assist in driving the hybrid vehicle V. The HMI device 150 is typically a display provided in the vehicle cabin and also includes a speaker and the like. The HMI device 150 provides the user with various information by outputting visual information (graphical information, text information), auditory information (audio information, sound information), and the like.

[0044] The E / G-ECU 200, which controls the operating state of the engine 1, similarly to the HV-ECU 100, includes a CPU, memory (ROM and RAM), input / output ports for inputting and outputting various signals, and performs predetermined calculations based on information from various sensors 120 and information from the HV-ECU 100 to control the engine 1.

[0045] 2 is a schematic diagram of the engine 1. The engine 1 is a diesel engine, an internal combustion engine in which fuel is injected from a fuel injection valve (injector) 14 into a combustion chamber formed in a cylinder (cylinder) 12 of an engine body 10, and compression self-ignition is performed. An air cleaner 22, an intercooler 24, and an intake throttle valve (electronically controlled throttle) 26 are provided in an intake passage 20 of the engine 1, and fresh air from which foreign matter has been removed by the air cleaner 22 is supercharged (compressed) by a compressor 32 of an electric supercharger 30, cooled by the intercooler 24, supplied to an intake manifold 28, and supplied to each combustion chamber from an intake port. The compressor 32 of the electric supercharger 30 is rotationally driven by a motor 34.

[0046] Exhaust gas discharged from the combustion chamber is collected in an exhaust manifold 50 and released to the outside air via an exhaust passage 52. Although not shown, the engine 1 is equipped with an EGR (Exhaust Gas Recirculation) device that recirculates a portion of the exhaust gas to the intake manifold 28.

[0047] In the exhaust passage 52, from the upstream side, an oxidation catalyst 70, a DPF (Diesel Particulate Filter) 72, a selective reduction catalyst 74, and an oxidation catalyst 76 are provided. The oxidation catalyst 70 oxidizes carbon monoxide (CO) in the exhaust gas to carbon dioxide (CO2) and converts hydrocarbons (HC) in the exhaust gas into water (H 2 O) and CO 2 It also oxidizes nitric oxide (NO) in the exhaust to nitrogen dioxide (NO 2 This is because the reduction reaction of nitrogen oxides (NOx) is NO and NO 2 When the ratio is 1:1, the reaction rate is fast, so there is a lot of NO in the exhaust of a diesel engine. 2 is oxidized to NO and NO 2 This is to bring the ratio closer to 1:1.

[0048] The DPF 72 collects particulate matter in the exhaust gas and purifies the exhaust gas by appropriately burning and removing the collected particulate matter. The selective catalytic reduction catalyst (hereinafter also referred to as SCR (Selective Catalytic Reduction) catalyst) 74 reduces and purifies NOx in the exhaust gas. The oxidation catalyst 76 oxidizes ammonia discharged (slips) from the SCR catalyst 74 and purifies the ammonia.

[0049] The SCR catalyst 74 is, for example, a ceramic carrier carrying copper (Cu) ion-exchanged zeolite as a catalyst, and exhibits a high purification rate by using ammonia (NH3) as a reducing agent. The ammonia used as the reducing agent is generated by hydrolysis of urea water supplied to the exhaust passage upstream of the SCR catalyst 74. A urea addition valve (urea water injection injector) 80 is provided in the exhaust passage upstream of the SCR catalyst 74, and urea water pumped from a urea water tank 82 by a pump (not shown) is injected from the urea addition valve 80 into the exhaust passage 52 upstream of the SCR catalyst 74.

[0050] In this embodiment, the SCR catalyst 74 is configured as an electrically heated catalyst (EHC (Electrically Heated Catalyst)). An electric heater 78 is provided integrally with the SCR catalyst 74 on the upstream side of the SCR catalyst 74, and the carrier carrying the catalyst can be heated by passing electricity through the electric heater 78. The catalyst carrier of the SCR catalyst 74 may be formed from a material (e.g., SiC (silicon carbide)) that becomes electrically resistive and generates heat when electricity is passed through it, to serve as an electrically heated catalyst.

[0051] The catalyst temperature sensor 122 detects the temperature, for example, the catalyst bed temperature, of the SCR catalyst 74. The motor 34 of the electric supercharger 30 and the electric heater 78 are driven by the electric power of the power storage device 7 whose voltage has been stepped down by the step-down converter 9.

[0052] In the engine 1 configured as described above, NOx in the exhaust gas is reduced and purified by the SCR catalyst 74. In order for the SCR catalyst 74 to effectively purify the NOx in the exhaust gas, it is desirable that the temperature of the SCR catalyst 74 reaches its activation temperature and is sufficiently activated. For example, when the temperature of the SCR catalyst 74 is 200° C. or higher, a purification rate of 90% or higher is achieved, and good purification performance is demonstrated.

[0053] <Normal control> In the present embodiment, the HV-ECU 100 executes normal control when the temperature of the SCR catalyst 74 reaches the activation temperature and is sufficiently activated. The normal control executed by the HV-ECU 100 is, for example, the following control.

[0054] First, the required driving force is calculated using the accelerator opening AP and the vehicle speed SPD as parameters, and the command torque Tm of the second MG 3 is obtained based on the required driving force. The electric power (driving electric power) PWs required for the second MG to output the command torque Tm is calculated, and the charging electric power PWb (which becomes a negative value when the SOC is higher than the target SOC*) is calculated based on the difference between the SOC of the power storage device 7 and the target SOC*. The driving electric power PWs and the charging electric power PWb are then added together to calculate the required power generation amount PW*.

[0055] The HV-ECU 100 calculates a target rotation speed NG* of the first MG 2 based on the required power generation amount PW*, and obtains a target torque TG* of the first MG 2 from the required power generation amount PW* and the target rotation speed NG*. The HV-ECU 100 controls the second inverter 5 so that the second MG 3 is driven by a command torque Tm, and outputs the target torque TG* to the engine ECU 200. The engine ECU 200 determines the fuel injection amount so that the torque of the first MG 2 becomes the target torque TG*, and operates (runs) the engine 1.

[0056] In order for the SCR catalyst 74 to effectively purify NOx in the exhaust gas, it is desirable that the temperature of the SCR catalyst 74 reaches its activation temperature and is sufficiently activated. In particular, when the hybrid system H is stopped and there is a long period of time until the next trip (activation of the hybrid system H), the temperature of the SCR catalyst 74 drops to the outside air temperature. In this way, when the temperature of the SCR catalyst 74 is low, the operation (driving) of the engine 1 is stopped, electricity is applied to the electric heater 78 to heat the SCR catalyst 74, and after the temperature of the SCR catalyst 74 reaches its activation temperature and the warm-up of the SCR catalyst 74 is completed, the engine 1 is started, thereby improving the purification rate of the exhaust gas.

[0057] In this embodiment, when the temperature of the SCR catalyst 74 is low at the start of a trip (when the hybrid system H is started), the operation (driving) of the engine 1 is stopped, electricity is applied to the electric heater 78 to heat the SCR catalyst 74, and EV driving is performed with the engine 1 stopped and the vehicle running on the power of the second MG 3 until the temperature of the SCR catalyst 74 reaches the activation temperature and warm-up of the SCR catalyst 74 is completed. This control is also referred to as startup control. In this embodiment, by setting the required power generation amount PW* to 0 until warm-up of the SCR catalyst 74 is completed, EV driving can be performed with the engine 1 stopped and the vehicle running on the power of the second MG 3.

[0058] 3 is a diagram showing the transition of the temperature and SCO of the SCR catalyst 74 in the case where the SOC is small at the start of a trip during startup control. FIG. 3(A) shows the change in temperature of the SCR catalyst 74, and FIG. 3(B) shows the change in SOC. When the hybrid system H starts at time t0, power is started to be supplied to the electric heater 78, and the vehicle starts to run in EV mode. The SCR catalyst 74 is heated by the electric heater 78, and as shown in FIG. 3(A), the temperature of the SCR catalyst 74 rises, and at time t2, the temperature of the SCR catalyst 74 reaches the activation temperature Ta. The activation temperature Ta may be, for example, a temperature at which the purification rate of the SCR catalyst 74 is 90% or more.

[0059] The electric power stored in the power storage device 7 is consumed by energizing the electric heater 78 and by the second MG3 during EV driving (note that, as described later, when the electric supercharger 30 is driven, the electric power is also consumed by the motor 34), and no power is generated by the first MG2. Therefore, as shown in FIG. 3B, the SOC decreases, and at time t1, it decreases to a lower limit value Sf. The lower limit value Sf is set as a value below which the deterioration of the power storage device 7 (battery) progresses, and is, for example, 20%. At time t1 when the SOC has decreased to the lower limit value Sf, the engine 1 is started to generate power by the first MG2, and the power storage device 7 is forcibly charged. Therefore, after time t1, the SOC gradually increases.

[0060] When the engine 1 is started at time t1, the temperature of the SCR catalyst 74 is lower than the activation temperature Ta, and so there is a concern that the engine 1 may be operated in a state in which the exhaust gas purification performance is relatively low.

[0061] Fig. 4 shows the transition of the temperature of the SCR catalyst 74 and the SCO when the SOC at the start of a trip is high during startup control. Fig. 4(A) shows the change in temperature of the SCR catalyst 74, and Fig. 4(B) shows the change in SOC. When the hybrid system H starts up at time t0, power begins to be supplied to the electric heater 78, and the vehicle starts running in EV mode.

[0062] As shown in FIG. 4(A), the temperature of the SCR catalyst 74 rises, and similarly to FIG. 3(A), at time t2, the temperature of the SCR catalyst 74 reaches the activation temperature Ta.

[0063] 4B, the SOC of the power storage device 7 is a large value at the start of a trip, and is maintained at or above the lower limit Sf at time t2 when the temperature of the SCR catalyst 74 reaches the activation temperature Ta. Then, when the warm-up of the SCR catalyst 74 is completed at time t2, the control shifts from startup control to normal control, and the engine 1 is started at time t3. The engine 1 and the first MG2 are controlled so that the amount of power generated by the first MG2 becomes the required power generation amount PW*, and the SOC gradually increases. When the engine 1 is started at time t3, the warm-up of the SCR catalyst 74 is completed, and therefore a decrease in the purification rate of the exhaust gas can be suppressed.

[0064] In this way, if the SOC at the start of the trip is such that electricity is supplied to the electric heater 78 until the temperature of the SCR catalyst 74 reaches the activation temperature Ta, and if the amount of stored electricity is sufficient for EV driving, the engine 1 is started after the SCR catalyst 74 is warmed up, thereby preventing a decrease in the exhaust purification rate at the start of the trip.

[0065] <SOC control during stop> In this embodiment, when the hybrid system H is stopped, stop-time SOC control is executed so that the SOC at the start of the trip is such that electricity is supplied to the electric heater 78 until the temperature of the SCR catalyst 74 reaches the activation temperature Ta, and the amount of stored electricity is sufficient for EV driving.

[0066] 5 is a schematic flowchart illustrating the process of stop-time SOC control executed by the HV-ECU 100. This flowchart illustrates the process executed when the power switch 121 is operated while the hybrid system H is in operation (started) and the hybrid system H is stopped.

[0067] When the power switch 121 is operated while the hybrid system H is in operation, first, in step (hereinafter, step is abbreviated as S) 10, it is determined whether or not the SOC of the power storage device 7 is equal to or higher than the lower limit value Sl at the start of running. The SOC may be the SOC calculated by the BAT-ECU 110. The lower limit value Sl at the start of running is the amount of electricity stored in the power storage device 7 at which the electric heater 78 is energized until the temperature of the SCR catalyst 74 reaches the activation temperature Ta and EV running is possible, and is calculated by a process for calculating the lower limit value Sl at the start of running. The lower limit value Sl at the start of running corresponds to the "predetermined value" in the present disclosure.

[0068] Fig. 6 is a schematic flowchart of a process for calculating lower limit value Sl at the start of traveling, which is executed by HV-ECU 100. This flowchart is also executed when power switch 121 is operated while hybrid system H is in operation (started) and hybrid system H is stopped. Referring to Fig. 6, in S20, the current position of hybrid vehicle V is acquired. For example, the current position may be acquired based on GPS information received by a GPS receiver of navigation device 140.

[0069] In the next step S21, the outside air temperature TH at the start of the next trip is estimated based on the current position of the hybrid vehicle V. For example, communication may be performed with a server 500 (see FIG. 1) having a weather information database (DB) via the communication device 130, and a transition of the outside air temperature (air temperature) at the current position within 24 hours from the present may be obtained from the weather information DB of the server 500, and the lowest temperature may be estimated as the outside air temperature TH at the start of the next trip. Note that if the user has input (set) the scheduled date and time of the next trip start (trip start) into the navigation device 140 or the like, the outside air temperature (air temperature) at the current position at the input scheduled date and time of the trip start may be obtained from the weather information DB of the server 500 and estimated as the outside air temperature TH.

[0070] In the next step S22, the heating required electric energy KW is calculated based on the outside air temperature TH at the start of the next driving, which was estimated in step S21. The heating required electric energy KW is the amount of electric energy required to raise the temperature of the SCR catalyst 74 to the activation temperature Ta by heating the electric heater 78, assuming that the temperature of the SCR catalyst 74 is the outside air temperature TH (the outside air temperature TH at the start of driving). The heating required electric energy KW can be calculated using the difference between the activation temperature Ta and the outside air temperature TH, the heat capacity of the SCR catalyst 74, the amount of heat released from the exhaust passage 52 and the SCR catalyst 74, and the like. In this embodiment, however, the relationship between the outside air temperature TH and the heating required electric energy KW is obtained in advance by experiments or the like, and a map is created in advance and stored in memory. Then, the heating required electric energy KW is calculated by referring to the map using the outside air temperature TH as a parameter.

[0071] In the next step S23, the amount of electric power DW required for EV driving is calculated. The amount of electric power DW required for EV driving is the amount of electric power consumed by the second MG3 during EV driving during the time required for raising the temperature of the SCR catalyst 74 to the activation temperature Ta by heating the electric heater 78, assuming that the temperature of the SCR catalyst 74 is the outside air temperature TH (the outside air temperature TH at the start of driving). For the amount of electric power DW required for EV driving, a map is created in advance by experiment or the like, using the outside air temperature TH as a parameter, and stored in memory. For example, when the outside air temperature is the outside air temperature TH and the temperature of the SCR catalyst 74 is the outside air temperature TH, the urban mode of the Worldwide harmonized Light duty Test Cycle (WLTC) mode is applied to drive the hybrid vehicle V in EV driving. During this EV driving, the rated power is energized (supplied) to the electric heater 78 to heat the SCR catalyst 74. Then, the amount of electric power consumed by the second MG3 (supplied to the second MG3) from the start of driving until the temperature of the SCR catalyst 74 reaches the activation temperature Ta is calculated as the amount of electric power required for EV driving DW, and a map is created using the outside air temperature TH as a parameter.The amount of electric power required for EV driving DW is then calculated by referring to the map using the outside air temperature TH as a parameter.The above-mentioned map of the amount of electric power required for heating KW using the outside air temperature TH as a parameter is also created in this experiment etc. from the amount of electric power consumed by the electric heater 78 from the start of driving until the temperature of the SCR catalyst 74 reaches the activation temperature Ta.

[0072] In the next step S24, a lower limit value S1 at the time of starting driving is calculated based on the amount of energy required for heating KW calculated in S22 and the amount of energy required for EV driving DW calculated in S23. For example, an SOC corresponding to the amount of energy stored in the power storage device 7 at the lower limit value Sf of the SOC plus the amount of energy required for heating KW and the amount of energy required for EV driving DW is calculated as the lower limit value S1 at the time of starting driving, and the process proceeds to S25.

[0073] In S25, it is determined whether the lower limit value Sl at the start of running calculated in S24 exceeds the upper limit value Su of the SOC of the power storage device 7. The upper limit value Su is a value at which the deterioration of the power storage device 7 progresses rapidly when the SOC exceeds this value, and may be, for example, 90%. If the lower limit value Sl at the start of running is equal to or less than the upper limit value Su, a negative determination is made and the current routine is terminated. If the lower limit value Sl at the start of running is greater than the upper limit value Su, an affirmative determination is made and the process proceeds to S26, where the lower limit value Sl at the start of running is guarded against by the upper limit value Su (the value of Sl is replaced with Su), and the current routine is terminated.

[0074] 5, in S10, it is determined whether the SOC of the power storage device 7 is equal to or greater than the lower limit S1 calculated as described above. If the SOC is smaller than the lower limit S1, a negative determination is made and the process proceeds to S11.

[0075] In S11, it is determined whether the engine 1 is operating, and if the engine 1 is stopped and the determination is negative, the process proceeds to S12, where the engine 1 is started, and then the process proceeds to S13. If the engine 1 is operating, a positive determination is made and the process proceeds to S13.

[0076] In S13, the engine 1 and the first MG2 are controlled so that the amount of power generated by the first MG2 becomes the required power generation amount PW*. The required power generation amount PW* may be set to a value where the engine 1 can be operated in a region where the fuel consumption rate of the engine 1 is small and the operating noise of the engine 1 is small, or may be set to an operating region where the power generation efficiency is high. As a result, power is generated by the first MG2 and the power storage device 7 is charged, so that the SOC increases.

[0077] In S14, the display of the HMI device 150 displays that the engine 1 is operating, and the process returns to S10. Note that the process in S14 may be performed by, for example, notifying the user that the engine 1 is operating by sound or voice.

[0078] If the SOC is equal to or higher than the lower limit Sl when the hybrid system H is stopped, or if the power storage device 7 is charged and the SOC is equal to or higher than the lower limit Sl when the hybrid system H is stopped, an affirmative determination is made in S10 and the program proceeds to S15.

[0079] In S15, the engine 1 is stopped, and then the current routine is terminated. In S15, when the engine 1 is stopped, the first MG 2 adjusts the crank angle to stop the engine 1 so that the engine 1 is stopped with the valve timing of the intake valve and the exhaust valve overlapping in at least one cylinder. If the display shows that the engine 1 is operating in S14, the display is stopped.

[0080] FIG. 7 is a diagram illustrating the transition of SOC in the stop SOC control. In FIG. 7, the vertical axis is the SOC of the power storage device 7, and the horizontal axis is time. At time ts, the power switch 121 is operated while the hybrid system H is in operation (started), and the hybrid system H is stopped. If the SOC is smaller than the lower limit value Sl at the start of running at time ts, a negative determination is made in S10 of FIG. 5, and S13 is processed, whereby power is generated by the first MG2 and the power storage device 7 is charged, so that the SOC increases. At time te, when the power storage device 7 is charged and the SOC becomes equal to or greater than the lower limit value Sl at the start of running, the engine 1 is stopped. As a result, the SOC at the start of the next trip becomes equal to or greater than the lower limit value Sl at the start of running, and the SOC at the start of the trip can be set to a storage amount that allows the electric heater 78 to be energized and EV running until the temperature of the SCR catalyst 74 reaches the activation temperature Ta.

[0081] 7, the target SOC* is a target value of the SOC of the power storage device 7 in normal control, and in this embodiment, it is set as an SOC region having a predetermined width. Therefore, the charging power PWb in normal control is a positive value when the SOC falls below the target SOC* region, and is a negative value when the SOC exceeds the target SOC* region. Moreover, when the SOC is within the target SOC* region, the charging power PWb is set to 0.

[0082] Start-up control In this embodiment, at the start of a trip, power is supplied to the electric heater 78 until the temperature of the SCR catalyst 74 reaches the activation temperature Ta, and startup control is executed to perform EV driving. Fig. 8 is a schematic flowchart illustrating the startup control process executed by the HV-ECU 100. This flowchart is executed when the power switch 121 is operated while the hybrid system H is stopped, and the hybrid system H is started up.

[0083] When the power switch 121 is operated and the hybrid system H is started, first in S30, it is determined whether the temperature Tc of the SCR catalyst detected by the catalyst temperature sensor 122 is equal to or higher than the activation temperature Ta. If the temperature Tc of the SCR catalyst 74 is lower than the activation temperature Ta, a negative determination is made and the process proceeds to S31.

[0084] In S31, rated power is applied (supplied) to the electric heater 78, and power is supplied to the motor 34 of the electric supercharger 30 to drive the compressor 32. When the valve timing of the intake valve and the exhaust valve do not overlap in at least one cylinder of the engine 1, the first MG 2 is driven to set the crank angle at which the valve timing of the intake valve and the exhaust valve overlap in at least one cylinder.

[0085] In the next step S32, with the engine 1 stopped, the second inverter 5 is controlled so that the second MG 3 is driven with command torque Tm, and EV driving is performed. As with normal control, the command torque Tm is calculated by calculating a required driving force using the accelerator opening AP and the vehicle speed SPD as parameters, and the command torque Tm of the second MG 3 is determined so that the required driving force is output from the drive wheels 8.

[0086] In S33, it is determined whether the SOC is equal to or lower than the lower limit Sf. If the SOC is greater than the lower limit Sf and the determination is negative, the process returns to S30.

[0087] If the temperature Tc of the SCR catalyst is equal to or higher than the activation temperature Ta and the determination in S30 is affirmative, or if the SOC is equal to or lower than the lower limit Sf and the determination in S33 is affirmative, the routine proceeds to S34. In S34, the control is shifted from the startup control to the normal control, and the current routine is terminated.

[0088] In this embodiment, by executing the startup control, at the start of a trip, the electric heater 78 is energized and EV driving is performed until the temperature of the SCR catalyst 74 reaches the activation temperature Ta. At this time, the electric supercharger 30 is driven, and fresh air (air) that has flowed from the intake passage 20 into the combustion chamber where the valve timing overlaps flows through the exhaust passage 52. As a result, the air heated by the electric heater 78 flows through the SCR catalyst 74, so that the SCR catalyst 74 can be efficiently heated.

[0089] Furthermore, if the amount of power consumed by EV driving becomes greater than initially expected, and the SOC of the power storage device 7 falls to the lower limit Sf before the warm-up of the SCR catalyst 74 is completed (if a positive determination is made in S33), the system transitions to normal control. When the system transitions to normal control, the engine 1 is started, power is generated by the first MG 2, the power storage device 7 is charged, and deterioration of the power storage device 7 can be prevented.

[0090] According to this embodiment, by executing the stop SOC control, the SOC at the start of the trip becomes equal to or higher than the lower limit Sl at the start of traveling, and the SOC at the start of the trip can be set to a stored amount that allows EV traveling by energizing the electric heater 78 until the temperature of the SCR catalyst 74 reaches the activation temperature Ta. Then, by executing the startup control, at the start of the trip, electricity is energized to the electric heater 78 until the temperature of the SCR catalyst 74 reaches the activation temperature Ta, and EV traveling is performed. Therefore, a decrease in the purification rate of the exhaust gas can be suppressed at the start of the trip.

[0091] (Variation 1) In the present embodiment, when the electric heater 78 is energized during the startup control, the electric supercharger 30 is driven. However, an electric air pump may be provided in the exhaust passage 52, and the electric air pump may be driven instead of or in addition to driving the electric supercharger 30. For example, with reference to FIG. 1, an electric air pump 40 shown by a broken line may be provided in the exhaust passage 52 upstream of the electric heater 78. Then, when the electric heater 78 is energized during the startup control, the electric air pump 40 may be driven so that air heated by the electric heater 78 flows through the SCR catalyst 74.

[0092] (Variation 2) In the present embodiment, the lower limit value Sl at the start of traveling is calculated based on the outside air temperature TH at the start of the next traveling. However, the method of calculating the lower limit value Sl at the start of traveling is not limited to this. In the second modification, the lower limit value Sl at the start of traveling is calculated by learning the amount of electric power discharged from the power storage device 7 when the electric heater 78 is energized until the temperature of the SCR catalyst 74 reaches the activation temperature Ta at the start of the hybrid system H and when EV traveling is performed.

[0093] Fig. 9 is a schematic flowchart illustrating the startup control process executed by HV-ECU 100 in Modification 2. In Modification 2, the running start lower limit value Sl is calculated in the startup control. The flowchart shown in Fig. 9 is obtained by adding S41 to S46 to the flowchart in Fig. 8, and S30 to S34 are the same as those in the flowchart in Fig. 8, so their description will be omitted.

[0094] 9, if a negative determination is made in S33, that is, if the electric heater 78 is energized until the temperature of the SCR catalyst 74 reaches the activation temperature Ta and EV driving is performed, the discharge energy HW of the power storage device 7 is calculated in S41. For example, the discharge energy HW may be calculated by calculating the discharge power from the value of the output current detected by the current sensor of the monitoring unit 7a and integrating the discharge power.

[0095] If the result of S33 is positive, the process proceeds to S42, where the discharge amount of power HW is set to the value (HW+α) obtained by adding the margin α to the discharge amount of power HW (after replacing the discharge amount of power HW with HW+α), and the process proceeds to S43.

[0096] In S43, the power amount learned value GW is calculated using the following formula (1). GW=GWn*(1-k)+HW*k····(1) GWn is the previous value of the power amount learned value GW. k is a weighting coefficient, which is set to a value greater than 0 and less than 1, and may be, for example, 0.1.

[0097] In S43, the power amount learned value GW calculated by the formula (1) is stored in memory as the previous value GWn, and the process proceeds to S44.

[0098] In S44, the lower limit value Sl at the start of traveling is calculated based on the learned power value GW calculated in S43. For example, the SOC corresponding to the amount of electricity stored in the power storage device 7 at the lower limit value Sf of the SOC plus the learned power value GW is calculated as the lower limit value Sl at the start of traveling, and the process proceeds to S45.

[0099] In S45, it is determined whether the lower limit value Sl at the start of running calculated in S44 exceeds the upper limit value Su of the SOC of the power storage device 7. If the lower limit value Sl at the start of running is equal to or less than the upper limit value Su, a negative determination is made and the process proceeds to S34. If the lower limit value Sl at the start of running is greater than the upper limit value Su, a positive determination is made and the process proceeds to S46, where the lower limit value Sl at the start of running is guarded against by the upper limit value Su (the value of Sl is replaced with Su), and the process proceeds to S34.

[0100] According to the second modification, when the hybrid system H is started up, the electric heater 78 is energized to heat the SCR catalyst 74 until the temperature of the SCR catalyst 74 reaches the activation temperature Ta, and the SOC (lower limit value Sl at the time of starting the driving) at which EV driving is possible is calculated based on the power amount learned value GW that learns the amount of power discharged from the power storage device 7 when the electric heater 78 is energized at the time of starting the hybrid system H until the temperature of the SCR catalyst 74 reaches the activation temperature Ta and the EV driving is performed. Therefore, the lower limit value Sl at the time of starting the driving can be calculated with high accuracy, taking into account the environment in which the hybrid vehicle V is placed and the driving characteristics of the user.

[0101] (Variation 3) 8, in the start-up control, the second inverter 5 is controlled so that the second MG 3 is driven with command torque Tm while the engine 1 is stopped, and EV driving is performed. At this time, the command torque Tm is calculated by using the accelerator opening AP and the vehicle speed SPD as parameters to calculate the required driving force, as in the normal control, and the command torque Tm of the second MG 3 is obtained so that the required driving force is output from the drive wheels 8.

[0102] In the hybrid vehicle V, the capacity of the power storage device 7 is relatively small. For this reason, if the amount of power consumed by the second MG3 during EV driving in the startup control is large, there is a concern that the SOC will frequently drop to the lower limit Sf before the warm-up of the SCR catalyst 74 is completed. In the third modification, when EV driving is performed, the output of the second MG3 is limited, and the power consumed by the second MG3 is limited, making it possible to prevent the SOC from dropping to the lower limit Sf before the warm-up of the SCR catalyst 74 is completed.

[0103] Fig. 10 is a schematic flowchart illustrating the startup control process executed by HV-ECU 100 in Modification 3. The flowchart shown in Fig. 10 is obtained by adding S51 and S52 to the flowchart in Fig. 8, and S30 to S34 are the same as those in the flowchart in Fig. 8, so their description will be omitted.

[0104] In Fig. 10, when EV driving is performed in S32, in S51, it is determined whether the SOC is equal to or lower than the output limit threshold Sd. The output limit threshold Sd is set as a value between the lower limit Sl at the start of driving and the lower limit Sf. If the SOC is greater than the output limit threshold Sd, a negative determination is made and the process proceeds to S33. If the SOC is equal to or lower than the output limit threshold Sd, a positive determination is made and the process proceeds to S52.

[0105] In S52, the magnitude of the command torque Tm is limited. For example, an upper limit may be set for the command torque Tm so that the command torque Tm does not exceed the upper limit. Alternatively, the command torque Tm may be multiplied by a coefficient kd (for example, 0.7) smaller than 1, and the value obtained is replaced with the command torque Tm (Tm←Tm*kd) to drive the second MG 3. After S52, the process proceeds to S33.

[0106] According to this third modification, Origin During EV driving under driving control, the output of the second MG3 is limited and the power consumed by the second MG3 is limited, thereby preventing the SOC from decreasing to the lower limit Sf before the warm-up of the SCR catalyst 74 is completed.

[0107] In this embodiment, in the stop-time SOC control, when the SOC becomes equal to or greater than the lower limit value Sl at the start of running, the engine 1 is stopped and charging of the power storage device 7 is terminated. However, even if the SOC becomes equal to or greater than the lower limit value Sl at the start of running, charging of the power storage device 7 may not be terminated, and the engine 1 may be stopped and charging of the power storage device 7 may be terminated when the SOC reaches an upper limit value Su, as shown by the dotted line in Fig. 7. Also, the engine 1 may be stopped and charging of the power storage device 7 may be terminated when the SOC reaches an arbitrary value between the lower limit value Sl at the start of running and the upper limit value Su. In this case, the arbitrary value may be a value several percent smaller than the upper limit value Su.

[0108] In this embodiment, an electric heater 78 is provided upstream of the SCR catalyst 74 integrally with the SCR catalyst 74, and the SCR catalyst 74 is configured as an EHC. However, instead of or in addition to the SCR catalyst 74, the oxidation catalyst 70 may be configured as an EHC.

[0109] In this embodiment, a diesel engine has been described as the engine 1, but the engine 1 may also be a gasoline engine (spark ignition engine). In this case, a three-way catalyst provided in the exhaust passage of the gasoline engine may be configured as the EHC.

[0110] In this embodiment, a series hybrid vehicle has been described as the hybrid vehicle V. However, the hybrid vehicle V may also be, for example, a series-parallel type hybrid vehicle in which the first MG 2 and the second MG 3 are connected by a power split mechanism formed of a planetary gear set.

[0111] The following are examples of embodiments of the present disclosure. 1) A hybrid vehicle (V) that is equipped with a hybrid system (10) including a traction motor (3), a power storage device (7) that supplies electric power to the traction motor (3), a generator (2) that is driven by an internal combustion engine (1) and generates electric power to be supplied to the power storage device (7), and a control device (100), and that is capable of EV running by running on the power of the traction motor (3) with the internal combustion engine (1) stopped, in which the internal combustion engine (1) is equipped with an electrically heated catalyst (74, 78) that can be heated by the electric power of the power storage device (7), and the control device A hybrid vehicle (100) is configured to operate the internal combustion engine (7) to charge the electricity storage device (7) until the SOC becomes equal to or greater than the predetermined value when the hybrid system (10) is stopped, and then stop the internal combustion engine (1), if the SOC of the electricity storage device (7) falls below a predetermined value, the predetermined value being an SOC that allows the electrically heated catalyst (74, 78) to be heated until the temperature of the electrically heated catalyst (74, 78) reaches an activation temperature when the hybrid system (10) is started, and allows EV driving.

[0112] In 2)1, when the hybrid system (10) is stopped and the SOC of the power storage device (7) falls below a predetermined value, the internal combustion engine (7) is operated to charge the power storage device (7) until the SOC reaches an upper limit value, and then the internal combustion engine (1) is stopped.

[0113] In 3)2, the upper limit of the SOC is the value at which the deterioration of the power storage device (7) progresses rapidly. The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not by the description of the embodiments described above, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0114] 1 engine, 2 first motor generator (first MG), 3 second motor generator (second MG), 4 first inverter, 5 second inverter, 6 boost converter, 7 power storage device, 7a monitoring unit, 8 drive wheels, 9 step-down converter, 10 engine body, 12 cylinder, 14 fuel injection valve, 20 intake passage, 22 air cleaner, 24 intercooler, 26 intake throttle valve, 28 intake manifold, 30 electric supercharger, 32 compressor, 34 motor, 40 electric air pump, 50 exhaust manifold, 52 exhaust passage, 70 oxidation catalyst, 72 DPF, 74 selective reduction catalyst (SCR catalyst), 76 oxidation catalyst, 78 electric heater, 80 urea addition valve, 82 urea water tank, 100 HV-ECU, 110 BAT-ECU, 120 various sensors, 121 Power switch, 122 catalyst temperature sensor, 130 communication device, 140 navigation device, 150 HMI device, 200 E / G-ECU, 500 server, H hybrid system, V hybrid vehicle.

Claims

1. A hybrid vehicle that is capable of EV running by running on power from the traction motor while the internal combustion engine is stopped, the hybrid system including a traction motor, a power storage device that supplies power to the traction motor, a generator that is driven by an internal combustion engine and generates power to be supplied to the power storage device, and a control device, the internal combustion engine includes an electrically heated catalyst that can be heated by the electric power of the power storage device; the control device is configured to, when the hybrid system is stopped, operate the internal combustion engine to charge the power storage device until the SOC becomes equal to or greater than the predetermined value, and then stop the internal combustion engine if an SOC of the power storage device falls below a predetermined value; the predetermined value is an SOC that allows the electrically heated catalyst to be heated until the temperature of the electrically heated catalyst reaches an activation temperature when the hybrid system is started, and allows the EV driving to be performed; the internal combustion engine includes an electric supercharger driven by electric power from the power storage device, The control device is configured to heat the electrically heated catalyst until the temperature of the electrically heated catalyst reaches an activation temperature when the hybrid system is started, and to drive the electric supercharger when the EV driving is being performed.

2. A hybrid vehicle that is capable of EV running by running on power from the traction motor while the internal combustion engine is stopped, the hybrid system including a traction motor, a power storage device that supplies power to the traction motor, a generator that is driven by an internal combustion engine and generates power to be supplied to the power storage device, and a control device, the internal combustion engine includes an electrically heated catalyst that can be heated by the electric power of the power storage device; the control device is configured to, when the hybrid system is stopped, operate the internal combustion engine to charge the power storage device until the SOC becomes equal to or greater than the predetermined value, and then stop the internal combustion engine if an SOC of the power storage device falls below a predetermined value; the predetermined value is an SOC that allows the electrically heated catalyst to be heated until the temperature of the electrically heated catalyst reaches an activation temperature when the hybrid system is started, and allows the EV driving to be performed; the internal combustion engine includes an air pump that supplies air to an exhaust passage upstream of the electrically heated catalyst; The control device is configured to heat the electrically heated catalyst until the temperature of the electrically heated catalyst reaches an activation temperature when the hybrid system is started, and to drive the air pump when the EV driving is performed.

3. A hybrid vehicle as described in claim 1 or claim 2, wherein the control device is configured to heat the electrically heated catalyst until the temperature of the electrically heated catalyst reaches an activation temperature when the hybrid system is started, and to limit the output of the traction electric motor when the EV driving is performed.

4. 4. The hybrid vehicle according to claim 3, wherein the control device is configured to limit the output of the traction motor when an SOC of the power storage device becomes equal to or lower than an output limit threshold.

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