JP5077830B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control device for a hybrid vehicle using an internal combustion engine and an AC motor as a power source.

  In recent years, the demand for hybrid vehicles using an internal combustion engine (engine) and an AC motor as power sources has increased. In this hybrid vehicle, for example, a system including an AC motor (electric motor) for driving the drive wheels of the vehicle and an AC motor (generator) for driving the internal combustion engine to generate electric power has been devised. Yes. In this system, fuel consumption is improved by driving each AC motor in conjunction with the internal combustion engine and driving the vehicle with the power, or by generating power with each AC motor and collecting it in the secondary battery. ing.

  Here, in a hybrid vehicle powered by an internal combustion engine and an AC motor, the exhaust gas discharged from the internal combustion engine is purified when power is generated by the internal combustion engine, so that the vehicle is powered by only the internal combustion engine. In addition, an exhaust gas purifying catalyst is provided in the exhaust pipe of the internal combustion engine.

Generally, when a catalyst is heated to a certain activation temperature, it becomes active and begins to purify exhaust gas. Therefore, when the temperature of the catalyst is low, it is necessary to warm up the catalyst early. In a hybrid vehicle, as one of controls for warming up the catalyst at an early stage, for example, a technique disclosed in Patent Document 1 below is known. In Patent Document 1, when there is a warm-up request for increasing the temperature of the catalyst, the power of the internal combustion engine is increased more than usual, thereby increasing the amount of exhaust gas discharged from the internal combustion engine and increasing the amount of exhaust heat. By doing so, the catalyst is warmed up early. Furthermore, in the technique of Patent Document 1, the load on the generator is increased in order to suppress an increase in vehicle driving torque caused by increasing the power of the internal combustion engine.
JP 2000-11604 A

  By the way, in the technique disclosed in Patent Document 1, since the load on the generator is increased when there is a catalyst warm-up request, the generated power of the generator is increased. The generated power is charged to the secondary battery. For this reason, in Patent Document 1, when the remaining chargeable amount that can be charged to the secondary battery is small, the secondary battery may be overcharged by the generated power of the generator. For this reason, the power of the internal combustion engine (amount of exhaust gas) cannot be increased so much that the catalyst cannot be warmed up early.

  Therefore, in view of the above problems, an object of the present invention is to warm up the catalyst early while solving the problem of secondary battery overcharging by catalyst warm-up control when there is a catalyst warm-up request. An object of the present invention is to provide a hybrid vehicle control device.

Accordingly, an invention according to claim 1 is directed to an internal combustion engine mounted on a vehicle, a catalyst for purifying exhaust gas, a generator that is driven by at least part of the power of the internal combustion engine, and generates electric power. And a motor driven by electric power generated by the generator and / or electric power discharged from the secondary battery, and the wheels are driven by the power of the internal combustion engine and / or the electric motor. In the control device of the hybrid vehicle that drives the battery, the remaining charge for calculating the remaining chargeable amount until the secondary battery is fully charged in consideration of the current charge amount (remaining charge amount) of the secondary battery To increase the power of the internal combustion engine and increase the power generated by the generator so as to increase the amount of exhaust gas discharged from the internal combustion engine when there is a demand amount calculation means and a catalyst warm-up request Thus a catalyst warm-up control means to suppress an increase in torque to drive the wheels, the catalyst warm-up control means, allowable charge corresponding to the remaining chargeable amount of the secondary battery calculated by the remaining chargeable amount calculating means In consideration of electric power, by controlling the electric power input to the electric motor, “overcharge prevention control” for limiting the electric power charged from the generator to the secondary battery is executed.

In this way, the secondary battery is charged from the generator by controlling the power input to the motor in consideration of the charge allowable power according to the remaining chargeable amount until the secondary battery is fully charged. It is possible to limit the power to be discharged so as not to exceed the charging capacity of the secondary battery, and even when the remaining chargeable amount of the secondary battery is small, the power of the internal combustion engine is increased and the amount of exhaust gas is increased. It is possible to warm up the catalyst early. Thereby, the catalyst can be warmed up early while solving the problem of secondary battery overcharging by the catalyst warm-up control.

  Here, simply controlling the electric power input to the electric motor may change the power (torque) of the electric motor and change the driving torque of the wheel against the intention of the driver. As in the invention, the catalyst warm-up control means may control the electric power input to the electric motor so that the driving torque of the wheels does not change during the execution of the overcharge prevention control. This makes it possible to warm up the catalyst early while preventing the wheel drive torque from changing against the driver's intention during the overcharge prevention control.

In addition, as in the invention according to claim 3, the apparatus includes a generated power calculation unit that calculates the generated power of the generator, and the catalyst warm-up control unit includes the generated power of the generator during the execution of the overcharge prevention control. Based on the difference from the chargeable power according to the remaining chargeable amount of the secondary battery, the surplus power exceeding the charge capacity of the secondary battery is calculated out of the generated power of the generator, and the surplus power is taken into account It is preferable to control the power input to the electric motor. In this way, if the surplus power exceeding the charge capacity of the secondary battery is calculated based on the difference between the generated power of the generator and the charge allowable power according to the remaining chargeable amount of the secondary battery, at least the surplus power It is possible to control the input power of the electric motor so that the electric power is consumed by the electric motor, and it is possible to limit the electric power charged from the generator to the secondary battery so as not to exceed the charging capacity of the secondary battery. .

  Further, as in the invention according to claim 4, the apparatus includes a power consumption calculation unit that calculates the power consumption of the motor, and the catalyst warm-up control unit is configured to prevent the overcharge when the power consumption of the motor is less than the surplus power. Control should be executed. Thus, when the power consumption of the motor is less than the surplus power exceeding the charging capacity of the secondary battery, the secondary battery may be overcharged. By controlling the input power of the motor so that the surplus power is consumed by the motor, it is possible to limit the power charged from the generator to the secondary battery so that the secondary battery is not overcharged. .

  Here, as in the invention according to claim 5, a charge amount calculating means for calculating the current charge amount of the secondary battery is provided, and the remaining chargeable amount of the secondary battery is set to the full charge amount of the secondary battery ( It may be calculated based on the difference between the (charge capacity) and the current charge amount (remaining charge amount).

  Further, as in the invention according to claim 6, the catalyst warm-up control means changes the operating efficiency of the electric motor so as not to change the electric power of the electric motor during execution of the overcharge prevention control. It is preferable to control power consumption. In this way, even when the input power of the motor is increased by increasing the generated power of the generator so that the power increase of the internal combustion engine is consumed by the generator during the overcharge prevention control, It becomes possible to drive the motor without changing the power while decreasing the driving efficiency of the motor and increasing the power consumption of the motor, and the driving torque of the wheel changes against the driver's intention. Can be prevented.

  As in the invention according to claim 7, the motor control means for controlling the electric motor by the sine wave PWM control system is provided, and the catalyst warm-up control means is configured to perform the sine wave PWM control system during the execution of the overcharge prevention control. The electric power input to the motor may be controlled by manipulating the current vector energized in the motor or the voltage vector applied to the motor.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 6.
First, a schematic configuration of a hybrid vehicle drive system will be described with reference to FIG.
As a power source for driving the wheels 11, an engine 12 (internal combustion engine) and a second AC motor 14 mainly used as an electric motor are mounted. The power of the crankshaft 15 of the engine 12 is divided into two systems by the planetary gear mechanism 16. The planetary gear mechanism 16 includes a sun gear 17 that rotates at the center, a planetary gear 18 that revolves while rotating on the outer periphery of the sun gear 17, and a ring gear 19 that rotates on the outer periphery of the planetary gear 18. The crankshaft 15 of the engine 12 is connected through a carrier that is not connected, the rotary shaft of the second AC motor 14 is connected to the ring gear 19, and the first AC motor 13 mainly used as a generator is connected to the sun gear 17. Are connected.

  A boost converter 21 is connected to the secondary battery 20 (DC power supply). The boost converter 21 boosts the DC voltage of the secondary battery 20 to generate a DC system voltage between the power line 22 and the ground line 23. And has a function of reducing the system voltage and returning power to the secondary battery 20. A smoothing capacitor 24 for smoothing the system voltage and a voltage sensor 25 for detecting the system voltage are connected between the power supply line 22 and the earth line 23, and a current flowing through the power supply line 22 is detected by the current sensor 26. .

  Further, a voltage-controlled three-phase first inverter 27 and a second inverter 28 are connected between the power supply line 22 and the ground line 23, and the first inverter 27 is connected to the first AC motor 13. While being driven, the second inverter 28 drives the second AC motor 14. The first inverter 27 and the first AC motor 13 constitute a first motor drive unit 29, and the second inverter 28 and the second AC motor 14 constitute a second motor drive unit 30.

  The main control device 31 is a computer that comprehensively controls the entire vehicle, and includes an accelerator sensor 32 that detects an accelerator operation amount (an accelerator pedal operation amount), a forward drive or reverse drive of a vehicle, a shift such as parking or neutral. Various sensors such as a shift switch 33 that detects an operation, a brake switch 34 that detects a brake operation, a vehicle speed sensor 35 that detects a vehicle speed, and the output signals of the switches are read to detect the driving state of the vehicle. The main control device 31 transmits and receives control signals and data signals between an engine control device 36 that controls the operation of the engine 12 and a motor control device 37 that controls the operation of the AC motors 13 and 14. The operation of the engine 12 and the AC motors 13 and 14 is controlled by 36 and 37 according to the driving state of the vehicle.

  Next, control of AC motors 13 and 14 will be described. The first and second AC motors 13 and 14 are three-phase permanent magnet type synchronous motors, each having a built-in permanent magnet, and a rotor rotational position sensor (not shown) for detecting the rotational position of the rotor. Is installed. The voltage-controlled three-phase first inverter 27 is connected to the DC voltage (voltage boosted by the boost converter 21) of the power supply line 22 based on the three-phase voltage command signals UU1, UV1, UW1 output from the motor control device 37. The first AC motor 13 is driven by converting the system voltage) into three-phase AC voltages U1, V1, and W1. Two-phase currents of the first AC motor 13, for example, a U-phase current iU1 and a W-phase current iW1 are detected by current sensors (not shown).

  On the other hand, the voltage-controlled three-phase second inverter 28 converts the DC voltage of the power supply line 22 into the three-phase AC based on the three-phase voltage command signals UU2, UV2, UW2 output from the motor control device 37. The second AC motor 14 is driven by converting to voltages U2, V2, and W2. Two-phase currents of the second AC motor 14, for example, a U-phase current iU2 and a W-phase current iW2 are detected by current sensors (not shown).

  The AC motors 13 and 14 function as generators when driven by the inverters 27 and 28 with negative torque. For example, when the vehicle decelerates, AC power generated by the second AC motor 14 by the deceleration energy is converted into DC power by the inverter 28 and the secondary battery 20 is charged. Normally, a part of the power of the engine 12 is transmitted to the first AC motor 13 via the planetary gear 18 and is generated by the first AC motor 13, and at least a part of the generated power is the second AC motor 14. The second AC motor 14 functions as an electric motor.

  Further, in a state where the power of the engine 12 is divided by the planetary gear mechanism 16 and the torque transmitted to the ring gear 19 is larger than the torque required for vehicle travel, the first AC motor 13 functions as an electric motor. The second AC motor 14 functions as a generator, and at least a part of the generated power is supplied to the first AC motor 13.

  When the motor controller 37 controls the torque of the first AC motor 13, the torque command value T 1 * output from the main controller 31, the U-phase current iU 1 and the W-phase current of the first AC motor 13 Based on iW1 (output signal of the current sensor) and the rotor rotational position θ1 (output signal of the rotor rotational position sensor) of the first AC motor 13, for example, a three-phase voltage command signal UU1, UV1 and UW1 are generated.

  First, based on the rotor rotational position θ1 of the first AC motor 13 (the output signal of the rotor rotational position sensor), the rotational speed N1 of the first AC motor 13 is calculated. Thereafter, in order to independently perform current feedback control of the d-axis torque control current id1 and the q-axis torque control current iq1 in the dq coordinate system set as the rotation coordinate of the rotor of the first AC motor 13, A torque control current vector it1 * (d-axis torque control current idt1 *, q-axis torque control current iqt1 *) corresponding to the torque command value T1 * of the AC motor 13 and the rotational speed N1 is calculated by a map or a mathematical expression.

  Thereafter, based on the U-phase and W-phase currents iU1 and iW1 (current sensor output signal) of the first AC motor 13 and the rotor rotation position θ1 (rotor rotation position sensor output signal) of the first AC motor 13. The actual current vector i1 (d-axis torque control current id1 and q-axis torque control current iq1) is calculated so that the deviation Δid1 between the d-axis torque control current idt1 * and the actual d-axis torque control current id1 becomes small. Calculates d-axis command voltage Vd1 * by PI control and calculates q-axis command voltage Vq1 * by PI control so that deviation Δiq1 between q-axis torque control current iqt1 * and actual q-axis torque control current iq1 is reduced. To do. The d-axis command voltage Vd1 * and the q-axis command voltage Vq1 * are converted into three-phase voltage command signals UU1, UV1, UW1, and these three-phase voltage command signals UU1, UV1, UW1 are sent to the first inverter 27. Output.

  When the torque control of the second AC motor 14 is performed, the torque command value T2 * output from the main controller 31 and the second AC motor 14 are controlled in the same manner as when the torque control of the first AC motor 13 is performed. Sine wave PWM control system based on the U-phase current iU2 and W-phase current iW2 (output signal of the current sensor) and the rotor rotational position θ2 of the second AC motor 14 (output signal of the rotor rotational position sensor). Three-phase voltage command signals UU1, UV1, UW1 are generated.

  First, the rotational speed N2 of the second AC motor 14 is calculated based on the rotor rotational position θ2 of the second AC motor 14 (the output signal of the rotor rotational position sensor). Thereafter, in order to independently control the current feedback of the d-axis torque control current id2 and the q-axis torque control current iq2 in the dq coordinate system set as the rotation coordinate of the rotor of the second AC motor 14, A torque control current vector it2 * (d-axis torque control current itt2 *, q-axis torque control current iqt2 *) corresponding to the torque command value T2 * of the AC motor 14 and the rotational speed N2 is calculated using a map or a mathematical expression.

  Thereafter, based on the U-phase and W-phase currents iU2 and iW2 (current sensor output signal) of the second AC motor 14 and the rotor rotation position θ2 (rotor rotation position sensor output signal) of the second AC motor 14. The actual current vector i2 (d-axis torque control current id2 and q-axis torque control current iq2) is calculated so that the deviation Δid2 between the d-axis torque control current idt2 * and the actual d-axis torque control current id2 becomes small. Calculates the d-axis command voltage Vd2 * by PI control and calculates the q-axis command voltage Vq2 * by PI control so that the deviation Δiq2 between the q-axis torque control current iqt2 * and the actual q-axis torque control current iq2 is reduced. To do. Then, the d-axis command voltage Vd2 * and the q-axis command voltage Vq2 * are converted into three-phase voltage command signals UU2, UV2, UW2, and these three-phase voltage command signals UU2, UV2, UW2 are output to the second inverter 28. To do.

  Here, in the hybrid vehicle, a catalyst (not shown) is provided in the exhaust pipe of the engine 12 in order to purify the exhaust gas discharged from the engine 12 into the exhaust pipe when the engine 12 generates power. Yes.

  An example of the exhaust purification system will be described. An air-fuel ratio sensor that linearly detects an air-fuel ratio of exhaust gas at an exhaust collecting portion where the exhaust manifolds of the cylinders of the engine 12 gather, and an exhaust gas downstream of the air-fuel ratio sensor. A catalyst such as a three-way catalyst that purifies the harmful components of CO, HC, NOx, etc., and an oxygen sensor that detects rich / lean exhaust gas that passes through the catalyst and flows downstream of the catalyst are installed. Based on the output signals of the air-fuel ratio sensor and the oxygen sensor, feedback control and sub-feedback control are performed so that the air-fuel ratio becomes a desired air-fuel ratio so that the exhaust gas purification efficiency becomes high.

  In general, the three-way catalyst has no harmful substances such as HC, CO, NOx, etc. in the exhaust gas, such as hydrogen, nitrogen, water vapor, Since it can be chemically changed to carbon dioxide, it is necessary to control the catalyst temperature to be the activation temperature.

  As one of the prior arts for warming up the catalyst, when there is a warm-up request for increasing the temperature of the catalyst, the engine power is increased more than usual while increasing the load by the generator. There is one that warms up the catalyst early by increasing the amount of exhaust gas discharged.

  However, in the prior art, when there is a catalyst warm-up request, the load on the generator is increased, so that the generated power of the generator increases. The battery will be charged. For this reason, when the remaining chargeable amount that can be charged to the secondary battery is small, the generated power of the generator is excessive with respect to the remaining chargeable amount of the secondary battery, and the secondary battery may be overcharged. There is. Therefore, in the prior art, even when there is a catalyst warm-up request, if the remaining chargeable amount of the secondary battery is small, the generated power of the generator is reduced to prevent overcharge of the secondary battery. Therefore, the power of the engine could not be increased so much. In this case, since the amount of exhaust gas discharged from the engine cannot be increased sufficiently, the catalyst cannot be warmed up early.

  Moreover, as shown in FIG. 3, the electric power that can be charged or discharged in the secondary battery is limited by the temperature. Here, FIG. 3 is a diagram showing the relationship between the discharge power Wout and the charge power Win of the secondary battery with respect to the temperature of the secondary battery. The lower the temperature of the secondary battery, the lower the discharge power Wout and charge of the secondary battery. It can be seen that the power Win is limited.

  For this reason, in the prior art, especially in the case of cold start when the temperature is low, the allowable maximum charge amount (full charge amount) that can be charged in the secondary battery is restricted, and accordingly, The remaining chargeable amount until the next battery is fully charged is limited. In this case, the power generated by the generator is immediately excessive with respect to the remaining chargeable amount of the secondary battery, and the secondary battery may be overcharged, so the power of the engine must be suppressed. For this reason, there is a possibility that the catalyst cannot be warmed up at an early stage, especially at the time of cold start where the temperature is low.

Therefore, in this embodiment, the remaining chargeable amount until the secondary battery 20 is fully charged is calculated, and the second alternating current is considered in consideration of the charge allowable power corresponding to the remaining chargeable amount. The power input to the motor (hereinafter referred to as “electric motor”) 14 is controlled, and the power charged in the secondary battery 20 from the first AC motor (hereinafter referred to as “generator”) 13 is supplied to the secondary battery 20. The secondary battery 20 is prevented from being overcharged by limiting so as not to exceed the charging capacity. In addition, in this embodiment, as further shown in FIG. 4, by changing the components of the d-axis torque control current and the q-axis torque control current of the motor 14 from the normal time and changing the operating efficiency of the motor 14, The power consumption consumed by the motor 14 is changed while the torque generated by the motor 14 is constant.

  Here, FIG. 4 shows rotational coordinates, and the d-axis is defined as an axis in the magnetic pole direction of the rotor of the AC motor (electric motor 14), and the q-axis is defined as an axis orthogonal to the d-axis. In an AC motor, the d-axis current (d-axis torque control current) can be treated independently as an excitation current component, and the q-axis current (q-axis torque control current) can be treated independently as a torque current component. In order to generate a predetermined torque, a map or a mathematical expression is set so that a vector composed of a d-axis torque control current, a q-axis torque control current, and a component is optimal (minimum). In FIG. 4, a vector composed of a d-axis torque control current (id0), a q-axis torque control current (iq0) and components is set as a normal operating point for an equal torque curve that outputs a predetermined torque. Become. In FIG. 4, when the operating point is changed so that the vector composed of the components of the d-axis torque control current and the q-axis torque control current becomes larger than the normal operating point with respect to the equal torque curve, The power consumption can be controlled to increase, and the power charged from the generator 13 to the secondary battery 20 can be reduced accordingly.

Hereinafter, a program for changing the electric power input to the electric motor 14 when the catalyst is warmed up will be described with reference to FIG. This program is repeatedly executed by the motor control device 37 at a predetermined cycle, and the electric power input to the electric motor 14 is controlled in consideration of the charge allowable power corresponding to the remaining chargeable amount of the secondary battery 20. It plays a role as a catalyst warm-up control means for executing “overcharge prevention control” for limiting the power charged from the generator 11 to the secondary battery 20.

  When this program is activated, it is determined in step S101 in FIG. 5 whether or not there is a request for warming up the catalyst installed in the exhaust pipe of the engine 12. If it is determined in step S101 that there is no catalyst warm-up request, the program is terminated.

  On the other hand, if it is determined in step S101 that there is a catalyst warm-up request, the process proceeds to step S102. Whether there is a catalyst warm-up request may be determined by detecting or estimating the temperature of the catalyst and determining whether the catalyst temperature has reached the activation temperature. In the case of detecting the catalyst temperature, it may be detected using a temperature sensor that directly detects the catalyst temperature. Further, when the catalyst temperature is estimated, it may be estimated based on the cooling water temperature of the engine 12, the integrated value of the intake air amount sucked into the engine 12, and the like.

Next, in step S102, a warm-up control of the catalyst is performed by executing a program shown in FIG. Then, in the next step S103, the current charge amount (remaining charge amount) of the secondary battery 20 is calculated, and from the difference between the full charge amount (charge capacity) of the secondary battery 20 and the current charge amount, The remaining chargeable amount until the secondary battery 20 is fully charged is calculated. Further, the generated power of the generator 13 is calculated, and the generated power of the generator 13 and the remaining charge of the secondary battery 20 are calculated. The surplus power exceeding the full charge amount of the secondary battery 20 in the generated power of the generator 13 is calculated from the difference from the charge allowable power according to the possible amount. The processing in step S103 serves as charge amount calculation means, remaining chargeable amount calculation means, and generated power calculation means in the claims.

  Here, the current charge amount of the secondary battery 20 may be calculated, for example, by integrating the charge / discharge amount of the secondary battery 20. The full charge amount of the secondary battery 20 may be a fixed value set in advance, but is preferably set according to the temperature as shown in FIG. At this time, the full charge amount of the secondary battery 20 may be the maximum charge amount that can be charged, but may be set with allowance for the maximum charge amount.

In addition, since the generated power of the generator 13 can be calculated based on the torque and the rotational speed of the generator 13, the surplus power W can be expressed as the torque Tg of the generator 13 and the rotational speed of the generator 13 as Ng. If the allowable charging power corresponding to the remaining chargeable amount of the secondary battery 20 is Wbat, it can be calculated by the following equation.
W = Tg × Ng−Wbat

  As described above, after calculating the surplus power W in step S103, the process proceeds to step S104, and the power consumption of the electric motor 14 is calculated. This power consumption is calculated based on the rotational speed of the motor 14, the driving torque (torque command value) of the motor 14, the d-axis torque control current Id, the q-axis torque control current Iq, and the d-axis voltage Vd, q. Using the shaft voltage Vq, it can be calculated by the following equation.

  Here, R is the resistance value of the motor 14, Ld is the d-axis inductance, Lq is the q-axis inductance, ω is the rotational angular velocity of the motor 14, φ is the magnetic flux of the generator 14, and θ is the phase difference between voltage and current. is there. The process of step S104 serves as power consumption calculation means in the claims.

  Then, it progresses to step S105 and the surplus electric power calculated by step S103 and the power consumption of the electric motor 14 calculated by step S104 are compared. If the surplus power W is less than the power consumption of the motor 14, that is, if the surplus power W can be consumed by the motor 14, the process proceeds to step S106, and the operating point of the motor 14 is usually maximized in operating efficiency. And the input power of the electric motor 14 is set.

  On the other hand, if the surplus power W is greater than the power consumption of the motor 14 in step S105, that is, if the surplus power W cannot be consumed with the power consumption at the current operating point of the motor 14, the process proceeds to step S107. The power consumption of the motor 14 is changed without changing the torque generated by the motor 14 by changing the operating point of the motor 14 along the equal torque curve in the direction of decreasing the operating efficiency and lowering the operating efficiency of the motor 14. Increase.

  More specifically, as shown in FIG. 4, the operating point is set so that the length of the vector composed of the d-axis torque control current, the q-axis torque control current and the components increases so that the generated torque of the motor 14 does not fluctuate. Is changed along the equal torque curve. Thereby, the electric power consumption of the electric motor 14 becomes larger than the normal time while the electric motor 14 generates the same torque. The method for changing the operating point is that a map as shown in FIG. 4 is stored in advance, and the d-axis torque control current and the q-axis torque control current are set so as to maintain a predetermined torque based on the map. It is good to change sequentially. Further, a map for calculating the d-axis torque control current and the q-axis torque control current from the surplus power and the generated torque of the electric motor 14 is stored in advance, and this map is used to store the d-axis torque control current and the q-axis torque control. The current may be set. When this process ends, the process returns to step S104, the power consumption of the motor 14 is calculated again, and the surplus power and the power consumption of the motor 14 are compared in the next step S104. By repeating this process, the electric power (operating point) input to the electric motor 14 is controlled so that surplus electric power can be consumed by the electric motor 14.

  By executing this program, it becomes possible to control the electric power input to the electric motor 14 so that surplus electric power exceeding the charging capacity of the secondary battery 20 is consumed by the electric motor 14, so the secondary battery 20 overcharges can be prevented. Accordingly, the catalyst warm-up control can be executed regardless of the remaining chargeable amount of the secondary battery 20, and the catalyst can be warmed up early. Moreover, since the electric power (operating point) input to the electric motor 14 is controlled so that the generated torque of the electric motor 14 does not fluctuate, the power consumption of the electric motor 14 can be increased without changing the driving torque of the wheels, It is possible to consume surplus power generated excessively by the generator 13, thereby preventing overcharge of the secondary battery 20.

Next, the catalyst warm-up control program will be described with reference to FIG.
When this program is started, first, the reference required power for the engine 12 is calculated in step S201. The required power for the engine 12 (required power output by the engine 12) is a reference required power of the engine that is calculated based on the driver's accelerator operation, the vehicle speed, and the amount of charge of the secondary battery 20. In order to calculate the reference required power for the engine 12, first, the required drive torque requested by the driver is calculated. This required driving torque is determined by various sensors and switches such as an accelerator sensor 32 that detects an accelerator operation amount (an accelerator pedal operation amount), a shift switch 33 that detects a shift operation (shift position), and a vehicle speed sensor 35 that detects a vehicle speed. An output signal is read and calculated based on the driving state of the vehicle. Next, the required power for the engine 12 is calculated using a map, formulas, etc. in consideration of the rotational speed of the electric motor 14 (AC motor), the charging request of the secondary battery 20, the loss of the system, etc. in the required driving torque. . The method for calculating the required power for the engine 12 is not limited to the above method.

  In step S202, the required power of the engine 12 for the catalyst warm-up request is calculated. Here, in order to increase the amount of exhaust gas discharged from the engine 12 and warm the catalyst early, an increase amount for increasing the power of the engine 12 with respect to the reference required power calculated in step S201 is calculated. The increase amount for increasing the power of the engine 12 may be a fixed value set in advance, or may be set based on the charge amount of the secondary battery 20. Moreover, you may set according to the temperature of a catalyst. In addition, when setting based on the charge amount of the secondary battery 20, it suppresses that the generated electric power of the generator 13 becomes excessive by setting so that this increase amount may become small, so that charge amount becomes large. It becomes possible to do. Moreover, when setting according to the temperature of a catalyst, it is good to set so that the motive power of the engine 12 may increase, so that the temperature of a catalyst is low. As a result, an increase in the power of the engine 12 can be set according to the temperature of the catalyst, so that the power of the engine 12 is not increased more than necessary, so that deterioration in fuel consumption can be suppressed. Become.

  Next, in step S203, the final required power of the engine 12 is calculated based on the required power of the engine calculated in steps S201 and S202, and the intake air is used to satisfy the final required power of the engine 12. Control the throttle to control the amount. In this case, based on the final required power of the engine 12, the target throttle opening is calculated using a map, a mathematical expression, and the like, and the actuator is controlled so that the throttle opening matches the target throttle opening.

  In step S204, the generator 13 is controlled with respect to the final required power of the engine 12 calculated based on the required power of the engine 12 calculated in steps S201 and S202. Here, if the required power of the engine 12 with respect to the warm-up request calculated in step S202 increases with respect to the driver's required driving torque, the vehicle will be driven against the driver's intention. The load of the generator 13 is controlled so that the power corresponding to the required power of the engine 12 for the warm-up request does not appear as the driving torque of the vehicle.

  In step S204, for example, the target rotational speed of the generator 13 is calculated based on the final required power of the engine 12, and the torque of the generator 13 is set so as to be the target rotational speed. The generator 13 may be controlled based on the target rotational speed and torque of the generator 13. It should be noted that the target rotational speed of the generator 13 is preferably set so that the driving torque of the motor 14 does not change using a nomographic chart of planetary gears. The torque of the generator 13 may be calculated by feedback control of the target rotational speed of the generator 13 and the actual rotational speed. Needless to say, the processing in step S204 is not limited to the above method.

  In this case, the difference between the driver's required driving torque and the required power of the engine 12 calculated in step S201 becomes the required driving torque of the electric motor 14.

  By executing this program, when there is a warm-up request for increasing the temperature of the catalyst, the amount of exhaust gas discharged from the engine 12 is sufficiently increased by setting the power of the engine 12 more than usual. Thus, the catalyst can be warmed up early. Moreover, since the load of the generator 13 is increased in order to suppress the increase in the driving torque of the vehicle caused by increasing the output of the engine 12, there has been a warm-up request for increasing the temperature of the catalyst. Sometimes, even if the power of the engine 12 increases, the driving torque of the vehicle is prevented from increasing against the driver's intention.

  In the present embodiment described above, the electric power input to the electric motor 14 can be controlled so that the electric motor 14 consumes surplus electric power that exceeds at least the charging capacity of the secondary battery 20, and overcharging of the secondary battery 20 is prevented. Can be prevented. Thereby, regardless of the remaining chargeable amount of the secondary battery 20, the power of the engine 12 can be increased and the catalyst warm-up control can be executed. The catalyst can be warmed up early while solving the charging problem.

In the present embodiment, since the electric power (operating point) input to the electric motor 14 is changed so that the driving torque of the vehicle (generated torque of the electric motor 14) does not change, the driving torque of the vehicle is against the driver's intention. It is possible to prevent the increase. Further, surplus power is calculated based on the difference between the generated power of the generator 13 and the charge allowable power corresponding to the remaining chargeable amount of the secondary battery 20, and the power input to the motor 14 in consideration of the surplus power Therefore, the power input to the motor 14 can be changed so that at least surplus power is consumed.

  Although the sine wave PWM control method has been described in the above embodiment, the AC motor may be torque controlled using a rectangular wave control method. Further, the program may be appropriately shared and processed by the main control device 31, the engine control device 36, and the motor control device 37.

1 is a configuration diagram showing a schematic configuration of a hybrid vehicle in an embodiment of the present invention. (A) is a figure for demonstrating operation of a duty ratio, (b) is a figure for demonstrating operation of a phase. It is a figure which shows the relationship between the temperature of a secondary battery, the discharge power Wout of a secondary battery, and the charge power Win. It is explanatory drawing of embodiment of this invention. It is a flowchart which shows an example of the program which determines the input electric power of the electric motor of embodiment of this invention. It is a flowchart which shows an example of the program of the catalyst warm-up control of embodiment of this invention.

Explanation of symbols

12. Engine (internal combustion engine)
13 ... 1st AC motor (generator)
14 ... Second AC motor (electric motor)
20 ... DC power supply (secondary battery)
31 ... main control device 36 ... engine control device 37 ... motor control device (catalyst warm-up control means, remaining chargeable amount calculation means, generated power calculation means, power consumption calculation means, charge amount calculation means)

Claims (7)

An internal combustion engine mounted on the vehicle;
A catalyst for purifying exhaust gas discharged from the internal combustion engine;
A generator that is driven by at least part of the power of the internal combustion engine to generate power;
A secondary battery capable of charging at least a part of the electric power generated by the generator;
A control apparatus for a hybrid vehicle, comprising: an electric motor driven by electric power generated by the generator and / or electric power discharged from the secondary battery, and driving wheels by the power of the internal combustion engine and / or the electric motor In
In consideration of the current charge amount of the secondary battery, a remaining chargeable amount calculating means for calculating a remaining chargeable amount until the secondary battery is fully charged,
When there is a request to warm up the catalyst, the power of the internal combustion engine is increased so as to increase the amount of exhaust gas discharged from the internal combustion engine, and the wheel is driven by increasing the power generated by the generator. Catalyst warm-up control means for suppressing an increase in torque to be performed,
The catalyst warm-up control means controls electric power input to the electric motor in consideration of charge allowable power corresponding to the remaining chargeable amount of the secondary battery calculated by the remaining chargeable amount calculation means. Then, overcharge prevention control for restricting electric power charged from the generator to the secondary battery is executed.   The said catalyst warm-up control means controls the electric power input into the said motor so that the torque which drives the said wheel may not change during execution of the said overcharge prevention control. Control device for hybrid vehicles. A generated power calculating means for calculating generated power of the generator;
The catalyst warm-up control means, during execution of the overcharge prevention control, based on the difference between the generated power of the generator and the charge allowable power corresponding to the remaining chargeable amount of the secondary battery. The surplus power exceeding the charging capacity of the secondary battery among the generated power is calculated, and the power input to the motor is controlled in consideration of the surplus power. Control device for hybrid vehicles. Power consumption calculating means for calculating the power consumption of the motor,
The control apparatus for a hybrid vehicle according to claim 3, wherein the catalyst warm-up control means executes the overcharge prevention control when the electric power consumption of the electric motor is less than the surplus electric power. A charge amount calculating means for calculating a current charge amount of the secondary battery;
2. The remaining chargeable amount calculation unit calculates the remaining chargeable amount of the secondary battery based on a difference between a full charge amount of the secondary battery and a current charge amount. The control apparatus of the hybrid vehicle as described in any one of thru | or 4.   The catalyst warm-up control means controls the power consumption of the motor by changing the operating efficiency of the motor so as not to change the power of the motor during the execution of the overcharge prevention control. The control apparatus of the hybrid vehicle as described in any one of Claims 1 thru | or 5. Motor control means for controlling the electric motor by a sine wave PWM control system;
The catalyst warm-up control means inputs to the motor by operating a current vector to be applied to the motor or a voltage vector to be applied to the motor by the sine wave PWM control method during execution of the overcharge prevention control. The hybrid vehicle control device according to claim 1, wherein the control device controls electric power.

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