Control method for hybrid vehicles and control device for hybrid vehicles

Abstract

To improve the regeneration efficiency of exhaust particulate filters. [Solution] The vehicle comprises an internal combustion engine 1 capable of being motorized by an electric motor, an electrically heated catalyst 7 located in the exhaust passage 3, and an exhaust particulate filter 8 located in the exhaust passage 3 downstream of the electrically heated catalyst 7, and regeneration of the exhaust particulate filter 8 is performed during the motoring. When regenerating the exhaust particulate filter 8, the vehicle controls the power supplied to the electrically heated catalyst so that the temperature of the exhaust particulate filter 8 reaches a regeneration target temperature set according to the amount of exhaust particulate matter accumulated on the exhaust particulate filter 8.

Description

Technical Field

[0001] The present invention relates to a control method for a hybrid vehicle and a control device for a hybrid vehicle.

Background Art

[0002] For example, in Patent Document 1, when a diesel engine stops, a negative pressure pump is driven to suck air from the downstream side of a DPF (Diesel Particulate Filter) disposed in an exhaust passage into the DPF, and the DPF is heated by a regeneration electric heater to increase its temperature, thereby performing DPF regeneration.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in Patent Document 1, during DPF regeneration, as the exhaust particulate matter (PM) deposited on the DPF decreases, the temperature of the DPF gradually decreases, and as a result, the regeneration efficiency of the GPF may decrease.

Means for Solving the Problems

[0005] The hybrid vehicle of the present invention includes an internal combustion engine capable of being motored by an electric motor, an electric heating catalyst disposed in an exhaust passage, and an exhaust particulate filter disposed in the exhaust passage and located downstream of the electric heating catalyst, and regenerates the exhaust particulate filter during motoring. The hybrid vehicle of the present invention controls the energization power of the electric heating catalyst so that the temperature of the exhaust particulate filter becomes a regeneration target temperature set according to the amount of exhaust particulate matter deposited on the exhaust particulate filter during regeneration of the exhaust particulate filter. [Effects of the Invention]

[0006] The hybrid vehicle of the present invention can efficiently regenerate the exhaust particulate filter in a short amount of time during the regeneration process. [Brief explanation of the drawing]

[0007] [Figure 1] A schematic diagram illustrating the system configuration of an internal combustion engine installed in a hybrid vehicle according to the present invention. [Figure 2] An explanatory diagram showing the relationship between the upper threshold for permitted regeneration and the target temperature for regeneration. [Figure 3] A timing chart showing an example of changes in various state quantities during the regeneration of an exhaust particulate filter. [Figure 4] A schematic diagram illustrating the correlation between the amount of exhaust particulate matter collected by the exhaust particulate filter and the temperature of the exhaust particulate filter. [Figure 5] A flowchart illustrating the control flow during the regeneration of the exhaust particulate filter. [Figure 6] Figure 5 shows a flowchart illustrating the EHC energization power feedback control, which is the subroutine for step S3. [Figure 7] A timing chart showing an example of changes in various state quantities during the regeneration of an exhaust particulate filter in another embodiment of the present invention. [Modes for carrying out the invention]

[0008] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0009] Figure 1 is a schematic diagram illustrating the system configuration of an internal combustion engine 1 installed in a hybrid vehicle (hereinafter simply referred to as "vehicle") according to the present invention.

[0010] The internal combustion engine 1 is mounted on the vehicle for power generation and generates electricity by driving an electric motor (motor generator) (not shown). The electricity generated by this electric motor is supplied to a battery (not shown) or a drive motor that drives the vehicle's drive wheels. The electricity supplied to the battery is used to charge the battery. The electric motor is equivalent to a generator and is capable of motorizing the internal combustion engine 1. The internal combustion engine 1 has an intake passage 2 and an exhaust passage 3. The internal combustion engine 1 uses gasoline as fuel, for example.

[0011] The intake passage 2 is equipped with an electrically operated first throttle valve 4 and an electrically operated second throttle valve 5 located upstream of the first throttle valve 4. The first throttle valve 4 controls the amount of intake air to the internal combustion engine 1 according to the load. The second throttle valve 5 is equivalent to a pressure control valve and controls the intake pressure upstream of the compressor, which will be described later. The second throttle valve 5 is also positioned downstream in the direction of intake air flow from the connection point between the intake passage 2 and the EGR passage 12, which will be described later.

[0012] In the exhaust passage 3, the following are arranged in series from upstream in the direction of exhaust flow: a first exhaust gas purification catalyst 6, an electroheated catalyst (EHC) 7, an exhaust particulate filter 8, and a second exhaust gas purification catalyst 9.

[0013] The first exhaust gas purification catalyst 6 consists of, for example, a three-way catalyst. A three-way catalyst can simultaneously purify NOx, HC, and CO in the exhaust gas with maximum conversion efficiency when the air-fuel ratio is within the so-called window centered around the stoichiometric air-fuel ratio.

[0014] The electrically heated catalyst 7 is a catalyst that generates heat when electricity is passed through it. For example, it has a structure in which a ceramic heating element that generates heat when electricity is passed through it is used as a catalyst support, and an appropriate catalytic metal that serves as a ternary catalyst or oxidation catalyst is coated onto its surface in a slurry.

[0015] The exhaust particulate filter 8 is a GPF (Gasoline Particulate Filter) that collects soot, which is particulate matter in the exhaust gas, and is capable of burning and removing the collected soot for regeneration under predetermined conditions. When the temperature of the exhaust particulate filter 8 reaches or exceeds a predetermined combustible temperature Tf, the deposited (collected) exhaust particulate matter can be burned and removed. The second exhaust purification catalyst 9 is a catalyst under the floor composed of, for example, a three-way catalyst.

[0016] The internal combustion engine 1 has a turbocharger 10 as a supercharger. The turbocharger 10 has a compressor (not shown) on the intake passage 2 and a turbine (not shown) on the exhaust passage 3 arranged coaxially and rotating integrally. The compressor is located upstream of the first throttle valve 4 in the intake flow direction and downstream of the second throttle valve 5 in the intake flow direction. The turbine is arranged upstream of the first exhaust purification catalyst 6 in the exhaust flow direction.

[0017] In the intake passage 2, an intercooler 11 is provided upstream of the first throttle valve 4 in the intake flow direction to cool the intake air compressed (pressurized) by the compressor and improve the filling efficiency.

[0018] The internal combustion engine 1 is capable of performing exhaust gas recirculation (EGR) that introduces (recycles) a part of the exhaust gas from the exhaust passage 3 to the intake passage 2 as EGR gas, and has an EGR passage 12 as an exhaust gas recirculation passage that branches from the exhaust passage 3 and is connected to the intake passage 2. One end of the EGR passage 12 is connected to the exhaust passage 3 at a position between the electric heating catalyst 7 and the exhaust particulate filter 8, and the other end is connected to the intake passage 2 at a position upstream of the second throttle valve 5 in the intake flow direction. An electric EGR valve 13 for adjusting (controlling) the flow rate of the EGR gas introduced into the intake passage 2 is provided in the EGR passage 12.

[0019] The EGR valve 13 is controlled by a control unit 14 that controls the internal combustion engine 1 to achieve a target valve opening degree.

[0020] The control unit 14 corresponds to a control section. The control unit 14 is a well-known digital computer provided with a CPU, a ROM, a RAM, and an input / output interface.

[0021] Output signals of various sensors such as a crank angle sensor 15 that detects the crank angle of the crankshaft of the internal combustion engine 1, an accelerator opening sensor 16 that detects the depression amount (accelerator opening) of the accelerator pedal, a first exhaust temperature sensor 17 that detects the exhaust temperature on the inlet side of the exhaust particulate filter 8, and a second exhaust temperature sensor 18 that detects the exhaust temperature on the outlet side of the exhaust particulate filter 8 are input to the control unit 14. Based on the input signals from the various sensors, the control unit 14 controls the valve openings of the first throttle valve 4 and the second throttle valve 5 in addition to the above-described EGR valve 13.

[0022] The control unit 14 calculates the engine speed of the internal combustion engine 1 from the detection signal of the crank angle sensor 15. The control unit 14 calculates the required load of the internal combustion engine 1 from the detection signal of the accelerator opening sensor 16. The control unit 14 is capable of detecting the SOC (State Of Charge), which is the ratio of the remaining charge amount to the charging capacity of the battery.

[0023] Further, the control unit 14 is capable of calculating the collected amount (deposited amount) of exhaust particulates (PM) collected by the exhaust particulate filter 8. The collected amount (deposited amount) of exhaust particulates (PM) collected by the exhaust particulate filter 8 is calculated, for example, from the operation history of the internal combustion engine 1. Note that the collected amount (deposited amount) of exhaust particulates (PM) collected by the exhaust particulate filter 8 may be calculated by the control unit 14 using a detection signal of a differential pressure sensor provided to detect the pressure difference between the inlet side and the outlet side of the exhaust particulate filter 8.

[0024] Then, when the control unit 14 receives a request to regenerate the exhaust particulate filter 8, it motors the internal combustion engine 1 to regenerate the exhaust particulate filter 8. Motoring means stopping the fuel injection of the internal combustion engine 1 and rotating the internal combustion engine 1 with the electric motor.

[0025] A regeneration request for the exhaust particulate filter 8 occurs, for example, when the amount of exhaust particulate matter collected (deposited) by the exhaust particulate filter 8 exceeds a preset regeneration request deposit amount Dr.

[0026] The regeneration of the exhaust particulate filter 8 ends when the amount of exhaust particulate matter accumulated on the exhaust particulate filter 8 falls below a target accumulation amount, which changes according to the battery's SOC. The target accumulation amount may be set to increase as the battery SOC decreases, for example. Alternatively, the target accumulation amount may be the amount of exhaust particulate matter accumulated on the exhaust particulate filter 8 when the battery SOC falls below a preset SOC threshold, for example.

[0027] As the exhaust particulate filter 8 is reduced by combustion during regeneration, its temperature gradually decreases. This means that the regeneration efficiency of the exhaust particulate filter 8 may decrease and the regeneration time may be prolonged due to the temperature drop associated with the decrease in the amount of exhaust particulate matter accumulated during regeneration.

[0028] Therefore, during the regeneration of the exhaust particulate filter 8, the control unit 14 controls the power supplied to the electric heating catalyst 7 so that the temperature of the exhaust particulate filter 8 changes according to the amount of exhaust particulate matter deposited (collected) on the exhaust particulate filter 8, which is set to a target regeneration temperature. In other words, during the regeneration of the exhaust particulate filter 8, the control unit 14 provides feedback control to the power supplied to the electric heating catalyst 7 so that the temperature of the exhaust particulate filter 8 reaches a predetermined target regeneration temperature.

[0029] During regeneration, the exhaust particulate filter 8 experiences a temperature increase due to the combustion of accumulated (collected) exhaust particulate matter. In other words, the more exhaust particulate matter accumulated (collected) in the exhaust particulate filter 8, the more likely it is to overheat during regeneration.

[0030] Figure 2 is an explanatory diagram showing the relationship between the regeneration permission upper threshold and the regeneration target temperature. The characteristic line S0 in Figure 2 is the regeneration permission upper threshold, which indicates the upper limit temperature according to the amount of exhaust particulate matter deposited, at which the exhaust particulate filter 8 will not overheat during regeneration. The regeneration permission upper threshold corresponds to the regeneration permission temperature at which regeneration of the exhaust particulate filter 8 is prohibited. The characteristic line S1 in Figure 2 shows the regeneration target temperature mentioned above.

[0031] In Figure 2, the region above the characteristic line S0 is the region where the exhaust particulate filter 8 overheats and is therefore the regeneration prohibited region. In Figure 2, the region below the characteristic line S0 is the region where the exhaust particulate filter 8 does not overheat and is therefore the regeneration permitted region.

[0032] The upper limit threshold for permitted regeneration is set to increase as the amount of exhaust particulate matter accumulation decreases.

[0033] The regeneration target temperature is a predetermined temperature lower than the upper limit threshold for permitted regeneration, regardless of the amount of exhaust particulate matter deposited, and its relationship with the upper limit threshold for permitted regeneration remains constant regardless of the amount of exhaust particulate matter deposited (collected) by the exhaust particulate matter filter 8. In other words, characteristic curve S1 is a parallel downward shift of characteristic curve S0, and the distance between them remains constant regardless of the amount of exhaust particulate matter deposited (collected). That is, the regeneration target temperature is set to change in line with the upper limit threshold for permitted regeneration as the amount of exhaust particulate matter deposited changes.

[0034] In Figure 2, the region above the characteristic line S0 is the region where the exhaust particulate filter 8 overheats and is therefore the regeneration prohibited region. In Figure 2, the region below the characteristic line S0 is the region where the exhaust particulate filter 8 does not overheat and is therefore the regeneration permitted region.

[0035] Furthermore, the regeneration target temperature defined by characteristic curve S1 is set to a value that provides a margin over the regeneration permit upper threshold defined by characteristic curve S0, so as to prevent the exhaust particulate filter 8 from overheating during regeneration.

[0036] In other words, the regeneration target temperature is set to a temperature in line with the upper limit threshold for permitted regeneration, just before the temperature at which regeneration of the exhaust particulate filter 8 is prohibited, and is always set to a temperature close to the upper limit within the temperature range in which regeneration of the exhaust particulate filter 8 is permitted.

[0037] As a result, during regeneration, the power supplied to the electric heating catalyst 7 is feedback-controlled so that the temperature of the exhaust particulate filter 8 reaches the target regeneration temperature, thereby suppressing a temperature drop in the exhaust particulate filter 8.

[0038] Figure 3 is a timing chart showing an example of changes in various state quantities during the regeneration of the exhaust particulate filter 8.

[0039] Time t1 in Figure 3 is the moment just before a regeneration request for the exhaust particulate filter 8 is generated, and the moment when power is supplied to the electric heating catalyst 7. Since the internal combustion engine 1 is used exclusively for power generation, the load and exhaust temperature are low at its operating point. Therefore, when a regeneration request for the exhaust particulate filter 8 is likely to occur, power is supplied to the electric heating catalyst 7 in advance to raise the temperature of the exhaust particulate filter 8 beforehand.

[0040] Time t2 in Figure 3 is the timing when a regeneration request for the exhaust particulate filter 8 occurs. The internal combustion engine 1 starts motoring at time t2 in Figure 3. In Figure 3, the engine speed of the internal combustion engine 1 remains the same during motoring as before and after motoring. Also, at time t2 in Figure 3, the electric heating catalyst 7 starts EHC power feedback control, which feedback controls the power supplied to the electric heating catalyst 7 so that the temperature of the exhaust particulate filter 8 reaches the regeneration target temperature. In Figure 3, the regeneration target temperature is lower than the regeneration permission temperature shown by the dashed line in Figure 3 during the motoring of the internal combustion engine 1.

[0041] Time t3 in Figure 3 is the point at which the amount of exhaust particulate matter (collection amount) collected by the exhaust particulate filter 8 falls below the target accumulation amount. The internal combustion engine 1 stops motoring at time t3 in Figure 3. Also, the electric heating catalyst 7 stops receiving power at time t3 in Figure 3.

[0042] The temperature of the electric heating catalyst 7 (EHC temperature) and the exhaust gas temperature behind the electric heating catalyst 7 (EHC rear gas temperature) begin to rise from time t1 onwards, and the rise stops when the power to the electric heating catalyst 7 is turned off at time t3 and the motoring of the internal combustion engine 1 ends.

[0043] In Figure 3, before time t2 and after time t3, the internal combustion engine 1 operates autonomously and generates power for the electric motor.

[0044] Figure 4 is a schematic diagram illustrating the correlation between the amount of exhaust particulate matter collected by the exhaust particulate filter 8 and the temperature of the exhaust particulate filter 8.

[0045] The thick solid line characteristic curve M in Figure 4 shows the change in the amount of exhaust particulate matter deposited during regeneration of the exhaust particulate filter 8 in the vehicle of the embodiment described above. The thick solid line characteristic curve Ft in Figure 4 shows the temperature change of the exhaust particulate filter 8 corresponding to characteristic curve M.

[0046] The characteristic lines m1 and m2, shown as thick dashed lines in Figure 4, represent the change in the amount of exhaust particulate matter deposited during regeneration of the exhaust particulate filter 8 in the comparative example vehicle, respectively. Furthermore, the characteristic line ft1, shown as a thick dashed line in Figure 4, shows the temperature change of the exhaust particulate filter 8 corresponding to characteristic line m1. The characteristic line ft2, also shown as a thick dashed line in Figure 4, shows the temperature change of the exhaust particulate filter 8 corresponding to characteristic line m2.

[0047] In the comparative example vehicle, the temperature of the exhaust particulate filter 8 is not increased during regeneration in accordance with the amount of exhaust particulate matter remaining in the exhaust particulate filter 8. Therefore, in the comparative example vehicle, the temperature of the exhaust particulate filter 8 decreases during motoring, and the regeneration efficiency of the exhaust particulate filter 8 decreases.

[0048] On the other hand, in the vehicle of the above-described embodiment, the temperature of the exhaust particulate filter 8 does not decrease during motoring, so the regeneration efficiency of the exhaust particulate filter 8 does not decrease.

[0049] Therefore, in the vehicle of the above-described embodiment, exhaust particulate matter collected by the exhaust particulate filter 8 can be efficiently processed (burned and removed) in a short time.

[0050] Furthermore, in the case of the comparative example vehicle, the amount of exhaust particulate matter that can be processed (burned and removed) by the exhaust particulate matter filter 8 changes significantly depending on how the temperature of the exhaust particulate matter filter 8 decreases during regeneration.

[0051] If the temperature of the exhaust particulate filter 8 during regeneration is at characteristic curve ft1, regeneration is possible until time t2. However, due to the low regeneration efficiency, the processing volume B1 is less than the processing volume A in this embodiment.

[0052] Furthermore, if the temperature of the exhaust particulate filter 8 during regeneration is at characteristic line ft2, regeneration is possible until time t3, and the regeneration time is extended. As a result, the processing amount B2 is higher than the processing amount A in this embodiment and the processing amount B1 when the temperature of the exhaust particulate filter 8 during regeneration is at characteristic line ft1.

[0053] Therefore, in the vehicle of this embodiment, the capacity of the exhaust particulate filter 8 can be set to, for example, Q1, including a margin. On the other hand, in the vehicle of the comparative example, the capacity of the exhaust particulate filter 8 can be set to, for example, Q2, including a margin.

[0054] In other words, in the comparative example vehicle, the amount of exhaust particles processed in one regeneration of the exhaust particulate filter 8 fluctuates greatly. Therefore, the capacity Q2 of the exhaust particulate filter 8 needs to be set so that it can handle the amount of exhaust particles that can be processed in one regeneration of the exhaust particulate filter 8, even when the processing amount is B1 or B2.

[0055] In the vehicle of this embodiment, when the exhaust particulate filter 8 is regenerated, the temperature drop of the exhaust particulate filter 8 is suppressed, and the exhaust fine particles collected in the exhaust particulate filter 8 can be processed until the target accumulation amount is reached. Therefore, in the vehicle of this embodiment, the fluctuation in the amount of exhaust fine particles that can be processed in one regeneration cycle of the exhaust particulate filter 8 (processing amount A) can be reduced, and the capacity Q1 of the exhaust particulate filter 8 can be made smaller compared to the comparative example (compared to Q2).

[0056] Figure 5 is a flowchart showing the control flow during regeneration of the exhaust particulate filter 8 in the vehicle of the embodiment described above.

[0057] In step S1, it is determined whether a regeneration request for the exhaust particulate filter 8, i.e., a GPF regeneration request, has occurred. If it is determined in step S1 that a regeneration request for the exhaust particulate filter 8 has occurred, the process proceeds to step S2. If it is determined in step S1 that no regeneration request for the exhaust particulate filter 8 has occurred, the routine is terminated. In step S1, even if no regeneration request for the exhaust particulate filter 8 has occurred, if it is determined that a regeneration request will occur soon, the electric heating catalyst 7 is energized in preparation for the regeneration request to be fulfilled.

[0058] In step S2, the motoring of the internal combustion engine 1 is initiated.

[0059] In step S3, the power supplied to the electrically heated catalyst 7 is feedback-controlled so that the temperature of the exhaust particulate filter 8 reaches a predetermined regeneration target temperature. In other words, step S3 performs EHC power supply feedback control.

[0060] Figure 6 is a flowchart of the subroutine for step S3, which shows the EHC energization power feedback control.

[0061] In step S31, it is determined whether the temperature of the exhaust particulate filter 8 is below the target regeneration temperature. If it is determined in step S31 that the temperature of the exhaust particulate filter 8 is below the target regeneration temperature, the process proceeds to step S32. If it is determined in step S31 that the temperature of the exhaust particulate filter 8 is above the target regeneration temperature, the process proceeds to step S33.

[0062] In step S32, the power supplied to the electric heating catalyst 7 is increased by a predetermined amount.

[0063] In step S33, the power supplied to the electric heating catalyst 7 is reduced by a predetermined amount.

[0064] In step S4, it is determined whether the amount of exhaust particulate matter (collection amount) collected by the exhaust particulate filter 8 is less than or equal to the target accumulation amount.

[0065] If it is determined in step S4 that the amount of exhaust particulate matter (collection amount) collected by the exhaust particulate filter 8 is less than or equal to the target collection amount, the process proceeds to step S5.

[0066] If it is determined in step S4 that the amount of exhaust particulate matter (collection amount) collected by the exhaust particulate filter 8 is not below the target amount, proceed to step S3.

[0067] In step S5, the power supply to the electric heating catalyst 7 is stopped.

[0068] In step S6, the motoring of internal combustion engine 1 is stopped.

[0069] In the above-described embodiment, when the exhaust particulate filter 8 is regenerated, the EGR valve 13 may be opened to introduce EGR gas into the intake passage 2, for example, as shown in Figure 7. Figure 7 is a timing chart showing an example of changes in various state quantities during the regeneration of the exhaust particulate filter 8 in another embodiment of the present invention.

[0070] As shown in Figure 7, in the vehicle of another embodiment of the present invention, the EGR valve 13 is controlled to be fully open between time t2 and time t3, which is the time of regeneration of the exhaust particulate filter 8. In the vehicle of the other embodiment of the present invention shown in Figure 7, the regeneration of the exhaust particulate filter 8 is controlled in the same procedure as in the vehicle of the above-described embodiment, except that the EGR valve 13 is controlled to be fully open between time t2 and time t3. Time t1 in Figure 7 is the timing just before a request for regeneration of the exhaust particulate filter 8 is made, and is the timing when power is supplied to the electric heating catalyst 7. Time t2 in Figure 7 is the timing when a request for regeneration of the exhaust particulate filter 8 is made. Time t3 in Figure 7 is the timing when the amount of exhaust particulate matter (collection amount) collected in the exhaust particulate filter 8 falls below the target amount.

[0071] In this way, by opening the EGR valve 13 during the regeneration of the exhaust particulate filter 8, the vehicle can suppress the temperature drop of the electric heating catalyst 7 and reduce the power supplied to the electric heating catalyst 7. In addition, during the regeneration of the exhaust particulate filter 8, the temperature drop of the exhaust components upstream of the electric heating catalyst 7 (such as the three-way catalyst) is suppressed.

[0072] Although specific embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention.

[0073] For example, the electrically heated catalyst 7 may be housed in series with the exhaust particulate filter 8 within the same casing, forming a single catalytic converter. Within the catalytic converter, the electrically heated catalyst 7 is located upstream of the exhaust particulate filter 8 in the direction of exhaust flow. In this case, one end of the EGR passage 12 is connected to the exhaust passage 3 downstream of the catalytic converter in the direction of exhaust flow.

[0074] The above-described embodiment relates to a control method for a hybrid vehicle and a control device for a hybrid vehicle. [Explanation of Symbols]

[0075] 1…Internal combustion engine 2…Intake passage 3… Exhaust passage 4…First throttle valve 5…Second throttle valve 6…First exhaust gas purification catalyst 7…Electric heating catalyst 8… Exhaust particulate filter 9…Second exhaust gas purification catalyst 10... Turbocharger 11…Intercooler 12...EGR passage 13…EGR valve 14…Control Unit 15... Crank angle sensor 16…Accelerator position sensor 17…First exhaust temperature sensor 18…Second exhaust temperature sensor

Claims

1. A control method for a hybrid vehicle comprising an internal combustion engine capable of motorization by an electric motor, an electrically heated catalyst located in the exhaust passage, and an exhaust particulate filter located in the exhaust passage downstream of the electrically heated catalyst, wherein the exhaust particulate filter is regenerated during the motorization process, A control method for a hybrid vehicle, characterized in that, when regenerating the exhaust particulate filter, the power supplied to the electric heating catalyst is controlled so that the temperature of the exhaust particulate filter reaches a regeneration target temperature set according to the amount of exhaust particulate matter accumulated on the exhaust particulate filter.

2. The system includes an EGR passage that allows a portion of the exhaust gas to be introduced into the intake passage as EGR gas from the downstream side of the above-mentioned electrically heated catalyst, and an EGR valve arranged in the EGR passage. The control method for a hybrid vehicle according to claim 1, characterized in that when the exhaust particulate filter is regenerated, the EGR valve is opened and the EGR gas is introduced into the intake passage.

3. The control method for a hybrid vehicle according to claim 1, characterized in that the above-mentioned electrically heated catalyst is integrated with the above-mentioned exhaust particulate filter to constitute a catalytic converter.

4. The above exhaust particulate filter is designed such that regeneration is prohibited when the temperature of the exhaust particulate filter exceeds a predetermined regeneration permit temperature. The above regeneration permission temperature is set to increase as the amount of exhaust particulate matter accumulation decreases. The control method for a hybrid vehicle according to claim 1, characterized in that the above-mentioned target regeneration temperature is set to be a predetermined temperature lower than the above-mentioned permitted regeneration temperature, regardless of the amount of exhaust particulate matter deposited, and to change in accordance with the above-mentioned permitted regeneration temperature.

5. The control method for a hybrid vehicle according to claim 1, characterized in that the regeneration of the exhaust particulate filter described above is terminated when the amount of accumulated exhaust particulate matter falls below a target accumulation amount that changes according to the battery's SOC.

6. An internal combustion engine that can be motorized by an electric motor, An electrically heated catalyst is placed in the exhaust passage, An exhaust particulate filter is located in the exhaust passage and downstream of the electrically heated catalyst, The system includes a control unit that performs regeneration of the exhaust particulate filter during the motoring process, The control unit described above controls the power supply to the electrically heated catalyst so that, when the exhaust particulate filter is regenerated, the temperature of the exhaust particulate filter reaches a regeneration target temperature set according to the amount of exhaust particulate matter accumulated on the exhaust particulate filter. This is a control device for a hybrid vehicle.

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