JP6729221B2 - Hybrid car - Google Patents

Description

The present invention relates to a hybrid vehicle, and more particularly to a hybrid vehicle equipped with a lithium ion capacitor.

Conventionally, as this type of lithium-ion capacitor, one provided with a positive electrode, a negative electrode containing a negative electrode active material capable of inserting and extracting lithium ions, and a non-aqueous electrolytic solution containing a lithium salt has been proposed (for example, See Patent Document 1). It is said that this lithium-ion capacitor has a high discharge capacity when operated at a low temperature or a high temperature, and is excellent in safety.

JP, 2015-173201, A

By the way, the deterioration of the lithium-ion capacitor, that is, the internal resistance increases due to charge and discharge, is recognized like the lithium-ion battery. It is considered that in a lithium-ion battery, when the battery is charged or discharged with a large current value, the in-plane salt concentration unevenness occurs in the electrolytic solution inside the battery, increasing the internal resistance. It is known that such deterioration is recovered early by leaving it to some extent or charging/discharging with a low current. Since the structure of the lithium ion capacitor is different from that of the lithium ion battery, it is not possible to perform the same deterioration recovery as the lithium ion battery.

The main purpose of the hybrid vehicle of the present invention is to recover the deterioration of the lithium ion capacitor and to drive according to the driver's request even when recovering the deterioration of the lithium ion capacitor.

The hybrid vehicle of the present invention adopts the following means in order to achieve the above-mentioned main object.

The hybrid vehicle of the present invention is
Engine,
A motor that can output power to the drive shaft,
A battery,
A lithium-ion capacitor,
A first converter that controls charging and discharging of the battery;
A second converter for controlling charge/discharge of the lithium ion capacitor;
A control device that controls the engine, the motor, the first converter, and the second converter so that the vehicle travels according to the required output required for traveling, and that calculates the input/output limit and the storage rate of the battery;
A hybrid vehicle equipped with
The control device calculates a deterioration index shown as a larger value as the degree of deterioration of the lithium ion capacitor is larger,
When the deterioration index is equal to or greater than a threshold value, the control device sets the deterioration discharge output of the lithium ion capacitor such that the discharge output increases as the deterioration index increases, and the charge output decreases as the deterioration index increases. Set the charge output at the time of deterioration of the lithium ion capacitor so that
(A) When the required output is within the range of the charge/discharge output during deterioration, the required output is controlled to be output from the lithium ion capacitor,
(B) When the required output is larger than the deterioration discharge output, the difference between the required output and the deterioration charge/discharge output is calculated as a remaining demand output, and the difference between the remaining demand output and the output limit of the battery is calculated. Is calculated as the output lower limit of the engine, and the engine output that is output from the engine when the engine is driven at the operating point at which the fuel consumption is optimal at the output lower limit or more and the engine is driven at the operating point and A difference output of the difference from the remaining required output is input to and output from the battery, and the lithium ion capacitor is controlled so that the discharge output at the time of deterioration is output.
It is characterized by

In the hybrid vehicle of the present invention, an engine, a motor capable of outputting power to a drive shaft, a battery, a lithium ion capacitor, a first converter that controls charging and discharging of the battery, and charging and discharging of the lithium ion capacitor are controlled. A second converter, and a control device that controls the engine, the motor, the first converter, and the second converter so that the vehicle travels at a required output required for traveling, and that calculates a storage ratio of the battery and an input/output restriction. .. In addition, the deterioration index of the lithium-ion capacitor is calculated such that the larger the deterioration degree of the lithium-ion capacitor is, the larger the deterioration index of the lithium-ion capacitor becomes. And the charging output at the time of deterioration of the lithium ion capacitor is set so that the charging output becomes smaller as the deterioration index becomes larger. In the experiment by the inventor, the deterioration of the lithium ion capacitor is promoted when the charging current is large and the discharging current is small, and the deterioration is recovered when the charging current is small and the discharging current is large. Therefore, by setting the discharge output during deterioration so that the discharge output increases as the deterioration index increases, and by setting the charge output during deterioration of the lithium ion capacitor so that the charge output decreases as the deterioration index increases, It is possible to recover the deterioration of the ion capacitor. Then, when the required output is within the range of the charge/discharge output during deterioration, the required output is controlled to be output from the lithium ion capacitor. On the other hand, when the required output is greater than the deterioration discharge output, the difference between the required output and the deterioration charge/discharge output is calculated as the remaining demand output, and the difference between the remaining demand output and the battery input/output limit is set as the engine output lower limit. The difference between the engine output output from the engine and the remaining demand output when the engine is operated at the operating point where the calculation is performed and the fuel consumption is optimal when the engine output is lower than the lower limit Control is performed so that the discharge output at the time of deterioration is output from the lithium ion capacitor. As a result, the deterioration of the lithium ion capacitor can be recovered, and the vehicle can travel according to the driver's request even when the deterioration of the lithium ion capacitor is recovered. Moreover, since the engine is driven at the driving point where the fuel consumption is optimum when the output is lower than the lower limit, it is possible to travel efficiently.

In such a hybrid vehicle of the present invention, when the lower limit of the output of the engine is a negative value, that is, when the output limit of the battery is larger than the remaining required output, the lithium ion capacitor does not output the discharge output at the time of deterioration, but does not output Alternatively, the battery may be controlled so that the remaining required output is output from the battery. By doing so, the frequency of operation of the engine can be reduced.

It is a block diagram which shows the outline of a structure of the hybrid vehicle 20 as one Example of this invention. 7 is a flowchart showing an example of an output control routine executed by HVECU 70. It is explanatory drawing which shows an example of the map for deterioration discharge output setting and the map for deterioration charge output setting. It is explanatory drawing explaining the mode that the engine output Pe is set based on the driving point where fuel consumption becomes optimal above the output lower limit Pemin.

Next, modes for carrying out the present invention will be described using examples.

FIG. 1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. As illustrated, the hybrid vehicle 20 of the embodiment includes an engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, a lithium ion capacitor 51, a first boost converter 54, and A second boost converter 55 and a hybrid electronic control unit (hereinafter referred to as HVECU) 70 are provided.

The engine 22 is configured as an internal combustion engine that outputs power using gasoline or light oil as fuel. The operation of the engine 22 is controlled by an electronic control unit for engine (hereinafter referred to as engine ECU) 24.

Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM for storing a processing program, a RAM for temporarily storing data, an input/output port, and a communication port. .. Signals from various sensors that detect the operating state of the engine 22 are input to the engine ECU 24 via input ports. The signal input to the engine ECU 24 via the input port includes a crank position θcr from the crank position sensor 23 that detects the rotational position of the crankshaft 26 and a cooling water temperature from a water temperature sensor that detects the temperature of the cooling water of the engine 22. Twe can be mentioned. Further, the cam position θca from a cam position sensor that detects the rotational position of the cam shaft that opens and closes the intake valve and the exhaust valve, the throttle position TP from the throttle valve position sensor that detects the position of the throttle valve, and the intake pipe are attached. The intake air amount Qa from the air flow meter, the intake air temperature Ta from a temperature sensor attached to the intake pipe, and the like can also be mentioned. Various control signals for driving the engine 22 are output from the engine ECU 24 through the output port. The control signal output from the engine ECU 24 via the output port is, for example, a drive signal to the fuel injection valve, a drive signal to a throttle motor for adjusting the position of the throttle valve, or an ignition coil integrated with an igniter. Control signals, control signals to the VVT 23, and the like can be given. The engine ECU 24 communicates with the HVECU 70, and controls the operation of the engine 22 by a control signal from the HVECU 70, and outputs data regarding the operating state of the engine 22 to the HVECU 70 as necessary. The engine ECU 24 also calculates the rotation speed of the crankshaft 26, that is, the rotation speed Ne of the engine 22, based on a signal from the crank position sensor 23 attached to the crankshaft 26.

The planetary gear 30 is configured as a single pinion type planetary gear mechanism. The sun gear of the planetary gear 30 is connected to the rotor of the motor MG1. The ring gear of the planetary gear 30 is connected to a drive shaft 36 that is connected to the drive wheels 38a and 38b via a differential gear 37. The crankshaft 26 of the engine 22 is connected to the carrier of the planetary gear 30.

The motor MG1 is configured as a known synchronous generator motor including a rotor in which a permanent magnet is embedded and a stator around which a three-phase coil is wound, and the rotor is connected to the sun gear of the planetary gear 30 as described above. Has been done. The motor MG2 is configured as a synchronous generator motor like the motor MG1, and has a rotor connected to the drive shaft 36. The motors MG1 and MG2 are driven by controlling the inverters 41 and 42 by the motor ECU 40. The inverters 41 and 42 are connected to the first boost converter 54 and the second boost converter 55 by the high voltage system power line 46. The inverters 41 and 42 are configured as well-known inverters including six transistors and six diodes. Since the inverters 41 and 42 are connected by the high voltage system power line 46, the power generated by either the motor MG1 or MG2 can be supplied to another motor. A smoothing capacitor 46a is attached to the positive electrode bus and the negative electrode bus of the high-voltage power line 46.

The first boost converter 54 is connected to a high voltage system power line 46 to which the inverters 41 and 42 are connected and a first power line 47 to which a battery 50 is connected. The first boost converter 54 is configured as a well-known step-up/down converter having two transistors, two diodes, and a reactor (not shown). The first boost converter 54 boosts the power of the first power line 47 and supplies it to the high-voltage system power line 46 by adjusting the ratio of the on-time of the two transistors by the motor ECU 40, or the high-voltage system power line 46. The power of the system power line 46 is stepped down and supplied to the first power line 47. A smoothing capacitor 47a is attached to the positive electrode bus and the negative electrode bus of the first power line 47.

The second boost converter 55 is connected to the high voltage system power line 46 and the second power line 48 to which the lithium ion capacitor 51 is connected. Similar to the first boost converter 54, the second boost converter 55 is configured as a well-known step-up/down converter having two transistors, two diodes, and a reactor. The second boost converter 55 boosts the power of the second power line 48 and supplies it to the high-voltage system power line 46 or adjusts the high-voltage system power line 46 by adjusting the ratio of the ON time of the two transistors by the motor ECU 40. The power of the system power line 46 is stepped down and supplied to the second power line 48.

Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM for storing a processing program, a RAM for temporarily storing data, an input/output port, and a communication port. .. Signals from various sensors necessary for driving and controlling the motors MG1 and MG2 and the first and second boost converters 54 and 55 are input to the motor ECU 40 via input ports. As signals from various sensors, rotational positions θm1 and θm2 from a rotational position detection sensor (not shown) that detects the rotational positions of the rotors of the motors MG1 and MG2, and a current that flows in each phase of the motors MG1 and MG2 are illustrated. The phase current from the current sensor can be mentioned. Further, the voltage VH of the high-voltage power line 46 from the voltage sensor (not shown) attached between the terminals of the capacitor 46a, and the voltage of the first power line 47 from the voltage sensor (not shown) attached between the terminals of the capacitor 47a. VL1 etc. can also be mentioned. Further, a reactor current IL1 from a current sensor (not shown) attached to the first boost converter 54, a reactor current IL2 from a current sensor (not shown) attached to the second boost converter 55, and the like can be cited. Various control signals for driving and controlling the motors MG1, MG2 and the first and second boost converters 54, 55 are output from the motor ECU 40 via the output ports. Examples of various control signals include switching control signals to the transistors of the inverters 41 and 42, switching control signals to the transistors of the first and second boost converters 54 and 55, and the like. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 drives and controls the motors MG1 and MG2 and the first and second boost converters 54 and 55 according to a control signal from the HVECU 70. Further, motor ECU 40 outputs to HVECU 70 data regarding the drive states of motors MG1, MG2 and first and second boost converters 54, 55 as necessary. The motor ECU 40 calculates the rotation speeds Nm1 and Nm2 of the motors MG1 and MG2 based on the rotation positions θm1 and θm2 of the rotors of the motors MG1 and MG2.

The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel hydrogen secondary battery, and is connected to the first power line 47 as described above. The lithium ion capacitor 51 is configured as, for example, a known lithium ion capacitor having a positive electrode, a negative electrode containing a negative electrode active material capable of inserting and extracting lithium ions, and a non-aqueous electrolytic solution containing a lithium salt. As before, it is connected to the second power line 48. The battery 50 and the lithium ion capacitor 51 are managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52.

Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM for storing a processing program, a RAM for temporarily storing data, an input/output port, and a communication port. .. A signal necessary for managing the battery 50 and the lithium ion capacitor 51 is input to the battery ECU 52 via an input port. As signals from the various sensors, the battery voltage Vb from the voltage sensor 50a installed between the terminals of the battery 50, the battery current Ib from the current sensor 50b installed at the output terminal of the battery 50, and the battery 50 are installed. The battery temperature Tb from the temperature sensor 50c can be mentioned. Moreover, the capacitor voltage Vc from the voltage sensor 51b installed between the terminals of the lithium ion capacitor 51, the capacitor current Ic from the current sensor 51a attached to the output terminal of the lithium ion capacitor 51, etc. can be mentioned. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 outputs data regarding the states of the battery 50 and the lithium ion capacitor 51 to the HVECU 70 as needed. In order to manage the battery 50 and the lithium ion capacitor 51, the battery ECU 52 calculates the charge ratios SOCb, SOCc based on the integrated value of the battery current Ib and the capacitor current Ic. The storage ratios SOCb and SOCc are ratios of the capacity of the electric power that can be discharged from the battery 50 and the lithium ion capacitor 51 at that time to the total capacity. In addition, battery ECU 52 outputs output limits Woutb and Woutc as allowable maximum values of electric power that can be discharged from battery 50 and lithium ion capacitor 51 based on charge ratios SOCb and SOCc and battery temperature Tb, and battery 50 and lithium ion capacitor 51. Input limits Winb and Winc are set as maximum allowable values (absolute values) that can be charged.

Further, when the charge ratio SOCc of the lithium ion capacitor 51 is less than the threshold value Sref to charge the lithium ion capacitor 51, the battery ECU 52 uses the following equation (1) to increase the degree of deterioration of the lithium ion capacitor 51. The D value as an index is calculated, and when the charge ratio SOCc is equal to or higher than the threshold value Sref or when the lithium ion capacitor 51 is discharged even when the charge ratio SOCc is less than the threshold value Sref, the forgetting factor α is multiplied to the D value at that time. And calculate a new D value. When the charge ratio SOCc of the lithium ion capacitor 51 is less than the threshold value Sref and the lithium ion capacitor 51 is not charged, the D value at that time is set to the initial value D(0). As the threshold value Sref, an upper limit value of the storage ratio SOCc at the start of charging, where deterioration is recognized, or a value in the vicinity thereof (for example, 50% or 40%) can be used. In the equation (1), α is a forgetting factor, β is a current factor, c0 is a limit threshold, and Δt is a minute time. D(N) and α(N) are the D value and the current value of the forgetting factor. The forgetting factor α and the current factor β are determined by the material of the lithium ion capacitor 51, and the limit threshold value c0 is determined by the remaining capacity and the temperature. As can be seen from the equation (1), the D value becomes an integrated value of a term proportional to the capacitor current Ic, and is attenuated with the passage of time. On the other hand, as described above, when the storage ratio SOCc is equal to or greater than the threshold value Sref, or when the lithium-ion capacitor 51 is discharged even when the storage ratio SOCc is less than the threshold value Sref, the D value at that time is multiplied by the forgetting factor α to obtain a new value. Calculate the D value. From these facts, the D value increases as the charging current value (capacitor current Ic) increases when the lithium ion capacitor 51 is charged in a state where the charge ratio SOCc of the lithium ion capacitor 51 is less than the threshold value Sref, and the charge ratio increases. When the SOCc is equal to or higher than the threshold value Sref or when the lithium ion capacitor 51 is discharged, the attenuation occurs.

Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM for storing a processing program, a RAM for temporarily storing data, an input/output port, and a communication port. Signals from various sensors are input to the HVECU 70 via input ports. As signals from various sensors, an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects an operation position of a shift lever 81, and an accelerator pedal position sensor 84 that detects a depression amount of an accelerator pedal 83 are detected. From the accelerator pedal position Acc, the brake pedal position BP from the brake pedal position sensor 86 that detects the amount of depression of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like. The HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port as described above. The HVECU 70 exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52.

The hybrid vehicle 20 of the embodiment thus configured is in an electric drive mode (EV drive mode) in which the engine 22 is stopped and the vehicle runs, or a hybrid drive mode (HV drive mode) in which the engine 22 is driven. To run.

When traveling in the EV traveling mode, it is basically controlled as follows. The HVECU 70 first sets the travel required output Pd* required for the drive shaft 36 based on the accelerator opening Acc from the accelerator pedal position sensor 84 and the vehicle speed V from the vehicle speed sensor 88 as the total required output P*. .. Then, the value 0 is set to the torque command Tm1* of the motor MG1. Then, torque command Tm2* of motor MG2 is set such that total required output P* is output to drive shaft 36. Next, based on the charge ratio SOCb of the battery 50 and the charge ratio SOCc of the lithium ion capacitor 51, the ratio of the power distributed to the battery 50 and the power distributed to the lithium ion capacitor 51 in the total required output P* ( Distribution ratios) k1 and k2 (k2=1−k1) are determined. Then, the electric power (k2·Pd*) obtained by multiplying the total required output P* by the distribution ratio k2 is output (input) from the lithium ion capacitor 51 within the range of the input/output limits Winc and Woutc of the lithium ion capacitor 51. The second boost converter 55 is controlled, and the first boost converter 54 is controlled so that the electric power obtained by subtracting the electric power input/output from the lithium ion capacitor 51 from the total required output P* is output (input) from the battery 50. .. The motor MG2 is controlled by the motor ECU 40 so that the travel required output Pd* is output.

When traveling in the HV traveling mode, the following control is basically performed. First, the HVECU 70 determines, based on the travel demand output Pd* required for the drive shaft 36 based on the accelerator opening Acc from the accelerator pedal position sensor 84 and the vehicle speed V from the vehicle speed sensor 88, based on the charge ratio SOCb of the battery 50. The battery charge/discharge required output Pb* (the discharge side output is positive) and the capacitor charge/discharge required output Pc* (the discharge side output is positive) set based on the storage ratio SOCc of the lithium ion capacitor 51. The value obtained by subtracting is set as the total required output P*. Next, the target rotational speed Ne* of the engine 22, the target torque Te*, the motor MG1, and the motor MG1, so that the total required output P* is output from the engine 22 and the traveling required output Pd* is output to the drive shaft 36. MG2 torque commands Tm1* and Tm2* are set. Subsequently, based on the target drive point of the motor MG1 (torque command Tm1*, rotation speed Nm1) and the target drive point of the motor MG2 (torque command Tm2*, rotation speed Nm2), the target voltage of the high voltage system power line 46. Set VH*. Then, by the motor ECU 40, the electric power Pb exchanged between the battery 50 and the inverters 41, 42 becomes the battery charge/discharge required output Pb*, and the voltage VH of the high voltage system electric power line 46 becomes the target voltage VH*. The first boost converter 54 is controlled, and the second boost converter 55 is controlled so that the power Pc exchanged between the lithium ion capacitor 51 and the inverters 41, 42 becomes the capacitor charge/discharge required output Pc*. The engine 22 is controlled by the engine ECU 24 so as to operate at the operating points of the target rotation speed Ne* and the target torque Te*, and the motors MG1 and MG2 output the torque of the set torque commands Tm1* and Tm2*. It is controlled by the motor ECU 40.

Next, the operation of the hybrid vehicle 20 thus configured, especially the operation when the lithium ion capacitor 51 is deteriorated will be described. FIG. 2 is a flowchart showing an example of the output control routine executed by the HVECU 70. This routine is repeatedly executed every predetermined time (for example, every several msec) when the shift position SP is the D position (forward position) and the travel required output Pd* is a positive value.

When the output control routine is executed, the HVECU 70 first executes a process of inputting data required for output control such as the total required output P* and the output limit Woutb, D value of the battery 50 (step S100). Here, as described above, the total required output P* is calculated from the traveling required output Pd* set based on the accelerator opening Acc and the vehicle speed V to the battery charge/discharge required output Pb* and the capacitor charge/discharge required output Pc. The value obtained by subtracting * and is set as the total required output P*. The output limit Woutb of the battery 50 is calculated by the battery ECU 52 based on the storage ratio SOCb of the battery 50 and the battery temperature Tb, and is input by communication. In addition, the D value calculated by the battery ECU 52 using the above equation (1) is input by communication.

When the data is input, the D value is compared with the threshold value Dref (step S110). As the threshold value Dref, a D value that can determine that it is necessary to recover the deterioration of the lithium ion capacitor 51 can be used, and can be determined by an experiment or the like. When the D value is less than the threshold value Dref, it is determined that the recovery of the deterioration of the lithium ion capacitor 51 is unnecessary, and the engine 22, the inverters 41, 42, and the first boost converter 54 are controlled by the normal output control in the EV running mode or the HV running mode described above. , The second boost converter 55 is controlled (step S120). This routine ends. The normal output control has been described above and does not form the core of the present invention, and thus detailed description thereof will be omitted.

When the D value is equal to or greater than the threshold value Dref, it is determined that the deterioration of the lithium ion capacitor 51 needs to be recovered, and the deterioration discharge output Pout of the lithium ion capacitor 51 is set based on the D value (step S130). In the embodiment, as the deterioration discharge output Pout, the relationship between the D value and the deterioration discharge output Pout is predetermined and stored as a deterioration discharge output setting map, and when the D value is given, the deterioration discharge output is calculated from the map. It is set by deriving the output Pout. FIG. 3 shows an example of the map for setting the discharge output during deterioration and the map for setting the charge output during deterioration. In the figure, the upper half is a map for setting the discharge output during deterioration, and the lower half is the map for setting the charge output during deterioration. The deterioration discharge output setting map is set such that the deterioration discharge output Pout increases as the D value increases. The deterioration charge output setting map is set such that the deterioration charge output Pin decreases as the D value increases. It was confirmed by the inventor's experiment that the lithium ion capacitor 51 is accelerated in deterioration when the charging current is large and the discharging current is small, and is recovered when the charging current is small and the discharging current is large. based on.

Subsequently, it is determined whether or not the set deterioration discharge output Pout is greater than or equal to the total required output P* (step S140). When the deterioration discharge output Pout is greater than or equal to the total required output P*, the capacitor output Pc is set. The total required output P* is set and the battery output Pb and the engine output Pe are set to the value 0 (step S150), and this routine is ended. The engine output Pe having a value of 0 is transmitted to the engine ECU 24, the operation of the engine 22 is stopped when the engine 22 is operating by the engine ECU 24, and the operation stopped state is maintained when the engine 22 is not operating. The battery output Pb and the capacitor output Pc having a value of 0 are transmitted to the motor ECU 40, the first boost converter 54 is controlled so that the discharge power of the battery 50 becomes a value of 0, and the discharge power of the lithium ion capacitor 51 becomes the capacitor output Pc. The second boost converter 55 is controlled so that In this case, the target rotational speed Ne* of the engine 22 and the target torque Te* are set to a value 0, the torque command Tm1* of the motor MG1 is set to a value 0, and the torque command Tm2* of the motor MG2 is set. A value obtained by dividing the total required output P* by the rotation speed Nd of the drive shaft 36 (may be the rotation speed obtained by multiplying the vehicle speed V by the conversion coefficient) is set, and the torque command Tm1* of value 0 is output from the motor MG1. At the same time, the transistors of the inverters 41 and 42 are switching-controlled so that the torque command Tm2* is output from the motor MG2.

On the other hand, when the deterioration discharge output Pout is less than the total required output P*, the total required output P* minus the deterioration discharge output Pout is set as the remaining required output ΔP (step S160), and the output of the battery 50 is output. It is determined whether the limit Woutb is greater than or equal to the set remaining request output ΔP (step S170). When the output limit Woutb of the battery 50 is equal to or greater than the remaining required output ΔP, the discharge output Pout during deterioration is set to the capacitor output Pc, the remaining required output ΔP is set to the battery output Pb, and the value 0 is set to the engine output Pe. (Step S180), the present routine ends. The capacitor output Pc and the battery output Pb are transmitted to the motor ECU 40. The motor ECU 40 controls the second boost converter 55 so that the discharge power of the lithium ion capacitor 51 becomes the capacitor output Pc, and the discharge power of the battery 50 is changed to the battery. The first boost converter 54 is controlled so that the output becomes Pb. Also in this case, the target rotation speed Ne* and the target torque Te* of the engine 22 are set to the value 0, the torque command Tm1* of the motor MG1 is set to the value 0, and the torque command Tm2* of the motor MG2 is set. Is set to a value obtained by dividing the total required output P* by the rotation speed Nd of the drive shaft 36 (may be the rotation speed obtained by multiplying the vehicle speed V by a conversion coefficient), and the torque command Tm1* having a value of 0 is output from the motor MG1. At the same time, the transistors of the inverters 41 and 42 are switching-controlled so that the torque command Tm2* is output from the motor MG2.

When the output limit Woutb of the battery 50 is less than the remaining required output ΔP, a value obtained by subtracting the output limit Woutb of the battery 50 from the remaining required output ΔP is set as the output lower limit Pemin of the engine 22 (step S190), and the output lower limit Pemin is set. Above, the driving point where the fuel consumption is optimum is set as the target rotation speed Ne* and the target torque Te* of the engine 22, and the output when the engine 22 is driven at the target rotation speed Ne* and the target torque Te* is set as the engine output Pe. (Step S200). FIG. 4 is an explanatory diagram for explaining how to set the engine output Pe based on the operating point at which the fuel efficiency is optimal at the output lower limit Pemin or more. In the figure, the upward-sloping curve is a fuel consumption optimum operation line in which the operating points that optimize the fuel consumption of the engine 22 are continuous curves. A plurality of substantially ellipses show contour lines according to fuel consumption, and the fuel consumption is higher toward the inside. The curves Pe1 and Pe2 indicate constant operating points when the output from the engine 22 is Pe1 and Pe2, and the curve Peop indicates the engine speed when the engine 22 is driven at the optimal fuel consumption optimal rotation speed Neop and optimal torque Peop. The output is Peop, indicating a certain operation point. Now, consider a case where the output lower limit Pemin is the output Pe1 smaller than the optimum output Peop. Since the output at the operation point where the fuel consumption is optimum at the output Pe1 or more is the optimum output Peop, the optimum output Peop is set for the engine output Pe, and the optimum rotation speed Neop and the target rotation speed Ne* and the target torque Te* are set. The optimum torque Teop is set. Considering the case where the output lower limit Pemin is the optimum output Peop, the optimum output Peop is set to the engine output Pe and the optimum rotation speed Neop and the optimum torque Ne* are set to the target rotation speed Ne* and the target torque Te*. The Top is set. When the output lower limit Pemin is the output Pe2 which is larger than the optimum output Peop, the output at the operation point where the fuel consumption is optimum at the output Pe2 or more is the output Pe2, so the output Pe2 is set as the engine output Pe and the target rotation speed Ne is set. For * and the target torque Te*, the rotation speed Ne2 and the torque Te2 at the intersection of the optimum fuel consumption operation line and the curve where the output Pe2 is constant are set. Then, the deterioration discharge output Pout is set to the capacitor output Pc (step S210), and the battery output Pb is set to a value obtained by subtracting the sum of the capacitor output Pc and the engine output Pe from the total required output P* ( (Step S220), this routine ends. When the engine output Pe is large and the battery output Pb has a negative value, the battery 50 is charged.

When the engine output Pe, the capacitor output Pc, and the battery output Pb are set in this way, the target torque Te* is output from the engine 22 and the torque command of the motor MG1 is set so that the rotation speed Ne of the engine 22 becomes the target rotation speed Ne*. When Tm1* is set and the torque command Tm1* is output from the motor MG1 from a value obtained by dividing the required travel output Pd* by the rotational speed Nd of the drive shaft 36 (which may be the vehicle speed V multiplied by a conversion factor). The torque command Tm2* of the motor MG2 is set as a value obtained by subtracting the torque acting on the drive shaft 36. Then, the torque commands Tm1* and Tm2* are transmitted to the motor ECU 40, and the transistors of the inverters 41 and 42 are switching-controlled so that the motor ECU 40 outputs the torque commands Tm1* and Tm2* from the motors MG1 and MG2. On the other hand, the target rotation speed Ne* and the target torque Te* are transmitted to the engine ECU 24, and the engine ECU 24 controls the engine 22 to operate at the operating points of the target rotation speed Ne* and the target torque Te*. At the same time, the capacitor output Pc and the battery output Pb are transmitted to the motor ECU 40, and the motor ECU 40 controls the second boost converter 55 so that the discharge power of the lithium ion capacitor 51 becomes the capacitor output Pc and the battery 50. First boost converter 54 is controlled such that the discharge power becomes battery output Pb. Thereby, the discharge output Pout at the time of deterioration is output from the lithium ion capacitor 51 to recover the deterioration of the lithium ion capacitor 51, and the travel required output Pd* required by the driver is output to the drive shaft 36 to travel. You can

In the hybrid vehicle 20 of the embodiment described above, the D value is calculated as an index having a larger value as the degree of deterioration of the lithium ion capacitor 51 is larger. When the D value is equal to or larger than the threshold value Dref, the larger the D value is, the larger the value is. The discharge output Pout at the time of deterioration of the lithium ion capacitor 51 is set so as to have a value. When the deterioration discharge output Pout is greater than or equal to the total required output P*, the total required output P* is set to the capacitor output Pc, and all of the total required output P* is covered by the discharge from the lithium ion capacitor 51. On the other hand, when the deterioration discharge output Pout is less than the total required output P*, the deterioration required discharge output Pout is subtracted from the total required output P* to calculate the remaining required output ΔP, and the output limit Woutb of the battery 50 is set to the remaining required output. When ΔP or more, the deterioration discharge output Pout is set to the capacitor output Pc, the remaining required output ΔP is set to the battery output Pb, and the deterioration discharge output Pout of the total required output P* is output from the lithium ion capacitor 51. The remaining output (remaining required output ΔP) is covered by discharging and the discharging from the battery 50 is covered. As a result, the traveling required output Pd* required by the driver can be output to the drive shaft 36 while traveling while recovering the deterioration of the lithium ion capacitor 51. Then, when the output limit Woutb of the battery 50 is less than the remaining required output ΔP, the output lower limit Pemin is calculated by subtracting the output limit Woutb of the battery 50 from the remaining required output ΔP, and the engine 22 with the optimum fuel consumption at the output lower limit Pemin or more is calculated. The output at the operating point is set as the engine output Pe, the capacitor output Pc is set to the deterioration discharge output Pout, and the battery output Pb is obtained by subtracting the sum of the capacitor output Pc and the engine output Pe from the total required output P*. A value that is set is set, and the total required output P* is covered by the engine output Pe, the capacitor output Pc, and the battery output Pb. As a result, the traveling required output Pd* required by the driver can be output to the drive shaft 36 while traveling while recovering the deterioration of the lithium ion capacitor 51.

In the embodiment, the output control in the case where the shift position SP is the D position (forward position) and the travel required output Pd* is a positive value has been described, but the shift position SP is the D position and the travel required output Pd* is negative. The output control in the case of the value of is as follows. It is to be noted that the travel required output Pd* has a negative value when the accelerator is off, and in that case, the travel required output Pd* corresponds to the brake pedal position BP from the brake pedal position sensor 86 and the vehicle speed V. Based on this, it is set as the braking force applied to the drive shaft 36. Then, this required travel output Pd* is set as the total required output P*.

In the output control when the travel required output Pd* is a negative value, first, the deterioration charge output Pin is set using the D value and the deterioration charge output setting map of FIG. Subsequently, it is determined whether or not the absolute value of the deterioration-time charge output Pin is greater than or equal to the absolute value of the total required output P*, and when the absolute value of the deterioration-time charge output Pin is equal to or greater than the absolute value of the total required output P*. , The total required output P* is set to the capacitor output Pc, and all the total required output P* is covered by charging from the lithium ion capacitor 51. When the absolute value of the deterioration-time charge output Pin is less than the absolute value of the total required output P*, the deterioration-time charge output Pin is subtracted from the total required output P* to calculate the remaining required output ΔP, and the input limit Winb of the battery 50 It is determined whether or not the absolute value is greater than or equal to the absolute value of the remaining request output ΔP. When the absolute value of the input limit Winb of the battery 50 is equal to or larger than the absolute value of the remaining required output ΔP, the charge output Pin at the time of deterioration is set to the capacitor output Pc and the remaining required output ΔP is set to the battery output Pb to obtain the total required output. Of P*, the charge output Pin at the time of deterioration is covered by charging the lithium ion capacitor 51, and the remaining output (remaining required output ΔP) is covered by charging the battery 50. When the absolute value of the input limit Winb of the battery 50 is less than the absolute value of the remaining required output ΔP, the capacitor output Pc is set to the deterioration charge output Pin and the battery output Pb is set to the input limit Winb to set the remaining required output ΔP. The remaining output, which is obtained by subtracting the input limit Winb from the above, is set to a brake output by a hydraulically driven mechanical brake (not shown), and the charge output Pin at the time of deterioration of the total required output P* is covered by charging the lithium ion capacitor 51. The input limit Winb is covered by charging the battery 50, and the remaining output is covered by a brake output by a hydraulically driven mechanical brake. Thus, even when the travel required output Pd* is a negative value, the travel required output Pd* required by the driver is output to the drive shaft 36 while traveling while recovering the deterioration of the lithium ion capacitor 51. You can

The hybrid vehicle 20 of the embodiment is configured to include the engine 22, the two motors MG1 and MG2, the planetary gear 30, the battery 50, the lithium ion capacitor 51, the first boost converter 54, and the second boost converter 55. The engine, the motor capable of outputting power to the drive shaft, the battery, the lithium ion capacitor, the first converter that controls the charging and discharging of the battery, and the charging and discharging of the lithium ion capacitor are not limited to Any hybrid vehicle may be used as long as the hybrid vehicle includes the second converter.

The embodiments for carrying out the present invention have been described above with reference to the embodiments. However, the present invention is not limited to these embodiments, and various embodiments are possible within the scope not departing from the gist of the present invention. Of course, it can be implemented.

INDUSTRIAL APPLICABILITY The present invention can be used in the hybrid vehicle manufacturing industry and the like.

20 hybrid vehicle, 22 engine, 23 crank position sensor, 24 engine electronic control unit (engine ECU), 26 crankshaft, 30 planetary gear, 36 drive shaft, 37 differential gear, 38a, 38b drive wheel, 40 motor electronic control unit (Motor ECU), 41, 42 inverter, 46 high voltage system power line, 46a, 47a capacitor, 47 first power line, 48 second power line, 50 battery, 50a, 51a voltage sensor, 50b, 51b current sensor, 50c Temperature sensor, 51 Lithium ion capacitor, 52 Battery electronic control unit (battery ECU), 54 First boost converter, 55 Second boost converter, 70 Hybrid electronic control unit (HVECU), 80 Ignition switch, 81 Shift lever, 82 Shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, MG1, MG2 motor.

Claims (1)

Engine,
A motor that can output power to the drive shaft,
A battery,
A lithium-ion capacitor,
A first converter that controls charging and discharging of the battery;
A second converter for controlling charge/discharge of the lithium ion capacitor;
A control device that controls the engine, the motor, the first converter, and the second converter so that the vehicle travels according to the required output required for traveling, and that calculates the input/output limit and the storage rate of the battery;
A hybrid vehicle equipped with
The control device calculates a deterioration index shown as a larger value as the degree of deterioration of the lithium ion capacitor is larger,
The control device sets the discharge output at the time of deterioration of the lithium ion capacitor such that the discharge output increases as the deterioration index increases, and the charge output increases as the deterioration index increases, only when the deterioration index is greater than or equal to the threshold value. The charge output at the time of deterioration of the lithium ion capacitor is set so that
(A) When the required output is within the range of the deterioration discharge output , the required output is controlled to be output from the lithium ion capacitor,
(B) When the required output is larger than the deterioration discharge output , the difference between the required output and the deterioration discharge output is calculated as the remaining demand output, and the difference between the remaining demand output and the output limit of the battery is calculated. The engine output is calculated as the lower limit of the output of the engine, and the engine output is output from the engine when the engine is driven at the operating point at which the fuel consumption is optimal at the output lower limit or more, and the engine output and the residual The difference output of the difference from the required output is input to and output from the battery, and the lithium ion capacitor is controlled to output the deterioration discharge output.
A hybrid vehicle characterized by the following.

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