CONTROL METHOD AND DEVICE FOR THE EXHAUST TEMPERATURE OF A POWER ENGINE, HYBRID DRIVE SYSTEM AND VEHICLE

Abstract

A power engine exhaust temperature control method for a hybrid drive system, comprising the steps of: detecting the exhaust temperature of a power engine (S10); when the exhaust temperature of the power engine is higher than a first exhaust temperature protection threshold, detecting an operating mode of a hybrid drive system, wherein the operating mode is a series mode or a parallel mode (S20); according to the operating mode of the hybrid drive system, determining a cooling method that involves shifting the operating point of the power engine (S30); and controlling the execution of the cooling method until the exhaust temperature of the power engine is lower than a second exhaust temperature protection threshold (S40). Furthermore, a power engine exhaust temperature control device, a hybrid drive system, and a vehicle are disclosed.

Description

CROSS-REFERENCE TO RELATED REGISTRATIONS

[0001] This application claims priority over Chinese patent application No. 202310493167.5, filed on May 4, 2023, entitled “CONTROL METHOD AND APPARATUS FOR EXHAUST GAS TEMPERATURE OF ENGINE, HYBRID POWER SYSTEM, AND VEHICLE”, which is incorporated herein in its entirety by reference. TECHNICAL AREA

[0002] This application relates to the field of hybrid power (or hybrid drive), in particular a control method and a control device for an exhaust gas temperature of a power engine, a hybrid drive system and a vehicle. BACKGROUND

[0003] If the exhaust gas temperature of a hybrid electric vehicle equipped with a combustion engine is too high, it must be reduced to protect the turbocharger and catalytic converter. One control method for a combustion engine's exhaust gas temperature in a related technology is as follows: if the engine's exhaust gas temperature exceeds a certain threshold, fuel enrichment is used to lower it. This control method increases overall fuel efficiency and, consequently, the fuel consumption of the hybrid electric vehicle. SUMMARY

[0004] This application is proposed to solve at least one of the aforementioned problems. According to a first aspect of this invention, a control method for the exhaust gas temperature of a power engine is provided. The control method for the exhaust gas temperature of the power engine is applied to a hybrid drive system (or hybrid power system), wherein an operating mode of the hybrid drive system comprises a series mode and a parallel mode, which utilize hybrid electrical power.The control procedure comprises: maintaining the exhaust gas temperature of the engine; maintaining the operating mode of a hybrid drive system when the exhaust gas temperature of the engine is higher than a first exhaust gas temperature protection threshold, the operating mode being either a series mode or a parallel mode; determining a cooling strategy, which includes shifting an operating point of the engine, based on the operating mode of the hybrid drive system; and executing the cooling strategy until the exhaust gas temperature of the engine is lower than a second exhaust gas temperature protection threshold.

[0005] In one embodiment of this application, determining the cooling strategy, which includes shifting the operating point of the engine, based on the operating mode of the hybrid drive system, comprises: determining the cooling strategy in response to the finding that the operating mode of the hybrid drive system is the series mode, wherein the cooling strategy comprises: increasing an output speed of the engine and decreasing an output torque of the engine under a condition in which the series mode is maintained unchanged as the operating mode.

[0006] In one embodiment of this application, determining the cooling strategy, which includes shifting the operating point of the engine, based on the operating mode of the hybrid drive system, comprises: obtaining a state-of-charge (SOC) value of a power battery in the hybrid drive system in response to the determination that the operating mode of the hybrid drive system is the parallel mode; and determining a cooling strategy, which includes reducing an output torque of the engine, based on the state-of-charge value of the power battery.

[0007] In one embodiment of this application, determining the cooling strategy, which includes reducing the output torque of the power machine, based on the state of charge of the power battery, comprises: in response to the determination that the state of charge of the power battery is greater than a state of charge protection threshold, determining the cooling strategy, wherein the cooling strategy comprises: reducing the output torque of the power machine under a condition in which the parallel mode is maintained unchanged as the operating mode.

[0008] In one embodiment of this application, determining the cooling strategy in response to the finding that the state of charge of the power battery is greater than the state of charge protection threshold further comprises: compensating for a reduction in the output torque delivered to a vehicle by the engine by means of a drive motor in the hybrid drive system.

[0009] In one embodiment of this application, determining the cooling strategy, which includes reducing the output torque of the power machine, based on the state of charge of the power battery, comprises: determining the cooling strategy in response to the finding that the state of charge of the power battery is not greater than the state of charge protection threshold, wherein the cooling strategy comprises: switching the operating mode of the hybrid drive system from the parallel mode to the series mode and increasing an output speed of the power machine and decreasing the output torque of the power machine.

[0010] In one embodiment of this application, the output power of the power machine is kept unchanged, while the output speed of the power machine is increased and the output torque of the power machine is reduced.

[0011] According to a second aspect of this application, a control device for the exhaust gas temperature of a power engine is provided. The control device for the exhaust gas temperature of a power engine is applied to a hybrid drive system, wherein one operating mode of the hybrid drive system comprises a series mode and a parallel mode, utilizing hybrid electrical power. The control device comprises a storage medium and a processor, wherein a computer program executable by the processor is stored on the storage medium, and the processor is configured, upon execution of the computer program, to perform one of the aforementioned control methods for the exhaust gas temperature of the power engine.

[0012] According to a third aspect of this application, a hybrid drive system is provided. One operating mode of the hybrid drive system comprises a series mode and a parallel mode, which utilize hybrid electrical power. The hybrid drive system includes one of the aforementioned control devices for the exhaust gas temperature of the engine.

[0013] According to a fourth aspect of this application, a vehicle is provided. The vehicle comprises: a vehicle body and one of the aforementioned hybrid drive systems, arranged on the vehicle body.

[0014] According to the control method and control device for an exhaust gas temperature of a power engine and the hybrid drive system provided by the embodiments of this application, when it is determined that the exhaust gas temperature of the power engine is higher than the first exhaust gas temperature protection threshold, it is first determined whether the hybrid drive system is in series mode or in parallel mode, and then a corresponding cooling strategy, which includes shifting the operating point of the power engine, is determined based on the operating mode, and the execution of the cooling strategy is controlled until the exhaust gas temperature of the power engine is lower than the second exhaust gas temperature protection threshold.Compared to a related technique where exhaust gas temperature is reduced by fuel enrichment, this embodiment of the present application uses different cooling strategies, each involving a shift in the operating point of the engine, in the different operating modes (i.e., the series and parallel modes, respectively). This effectively reduces the exhaust gas temperature of the engine, avoids fuel enrichment during the exhaust gas temperature reduction, and reduces the fuel consumption caused by fuel enrichment, thereby reducing the fuel consumption of the hybrid drive system and achieving energy savings and emission reductions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] To more clearly describe the technical solutions in embodiments of the present application, the attached drawings, which are required for describing some embodiments of the present application, are briefly described below. As can be seen, the drawings in the following description relate only to some embodiments of the present application. Other drawings can be derived from these drawings by a person skilled in the art without inventive step. They show: Fig. 1 an energy flow diagram in a serial mode based on hybrid electrical power according to an embodiment of the present application; Fig. 2 an energy flow diagram in a parallel mode based on hybrid electrical power according to an embodiment of the present application; Fig. 3 a flowchart of a control procedure for an exhaust gas temperature of a power engine according to an embodiment of the present application; Fig. 4 a flowchart of a control procedure for an exhaust gas temperature of a power engine according to a further embodiment of the present application; Fig. 5 a diagram showing characteristics of an exhaust gas temperature of a power engine according to an embodiment of the present application; Fig. 6 a diagram of the displacement of an operating point of a power machine in a serial mode according to an embodiment of the present application; Fig. 7 a diagram of the displacement of an operating point of a power machine in a parallel mode according to an embodiment of the present application; and Fig. 8 a block diagram of a control device for an exhaust gas temperature of a power engine according to an embodiment of the present application. DESCRIPTION OF EXAMPLES OF EXECUTION

[0016] To illustrate the tasks, technical solutions, and advantages of the present application, exemplary embodiments of the present application are described in detail below with reference to the accompanying drawings. As can be seen, the described exemplary embodiments are only some, and not all, of the exemplary embodiments of the present application. The present application is not limited to the exemplary embodiments described here. Based on the exemplary embodiments of the present application described here, all further exemplary embodiments that a person skilled in the art arrives at without inventive step are within the scope of protection of the present application.

[0017] The following description includes numerous specific details to facilitate a more thorough understanding of the present application. However, it is evident to those skilled in the art that the present application can be implemented without one or more of these details. In other examples, certain technical features known in the art are not described to avoid confusion with the present application.

[0018] It should be noted that the present application can be implemented in various forms and is not limited to the embodiments given here. Rather, these embodiments are presented for the purpose of a thorough and complete disclosure, which will fully convey to those skilled in the art the scope of the present application.

[0019] The terms used herein serve only to describe specific embodiments and are not intended to limit the present application. As used herein, the singular forms "a", "an", and "said" are to include the plural forms unless the context clearly indicates otherwise. It is also understood that the terms "constitute" and / or "comprise," when used in this specification, indicate the presence of the aforementioned features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. As used herein, the term "and / or" includes any and all combinations of the items listed.

[0020] For a thorough understanding of the present application, a detailed structure is presented below to illustrate the technical solutions proposed in the present application. Optional embodiments of the present application are described in detail below. However, in addition to these detailed descriptions, other implementations of the present application are possible.

[0021] Some embodiments of the present application are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments can be combined with one another, provided that no conflict arises.

[0022] This application provides a control method for the exhaust gas temperature of a power engine. The exhaust gas temperature control method is applied to a hybrid drive system. One operating mode of the hybrid drive system includes a series mode and a parallel mode, both utilizing hybrid electrical power. It should be noted that the operating mode of the hybrid drive system is not limited to the series and parallel modes utilizing hybrid electrical power; that is, the operating mode of the hybrid drive system may include other operating modes in addition to the series and parallel modes utilizing hybrid electrical power.

[0023] If, as in Fig. 1 and Fig. As shown in Figure 2, the series and parallel modes described above, which utilize the hybrid electrical power, are implemented. The hybrid drive system comprises at least one internal combustion engine. The internal combustion engine may be, but is not limited to, a gasoline or diesel engine. The hybrid drive system further comprises a generator, a power battery, and a drive motor.

[0024] Reference is made to an energy flow diagram of the hybrid drive system in a series mode based on the hybrid electrical power, which is shown in Fig. Figure 1 shows that in series mode, the engine only drives the generator to produce power. The generator's output power is supplied to the generator, and the power produced by the generator is transferred to both the battery for storing electricity and the drive motor. The battery can also supply power to the drive motor, which in turn drives the vehicle's wheels. Reference is made to an energy flow diagram of the hybrid drive system in parallel mode based on hybrid electric power, shown in Figure 1. Fig. Figure 2 shows that in parallel mode, at least either the power unit or the drive motor can drive the vehicle's wheels; that is, the power to drive the vehicle's wheels can come from either the power unit or the drive motor.

[0025] With reference to Fig. 3 In an embodiment of the present application, a control method for an exhaust gas temperature of a power engine of a hybrid drive system is provided, comprising the following steps.

[0026] In step 1, the exhaust gas temperature of the engine is obtained.

[0027] In step 2, an operating mode of a hybrid drive system is obtained if the exhaust gas temperature of the engine is higher than a first exhaust gas temperature protection threshold, the operating mode comprising a series mode or a parallel mode.

[0028] In step 3, a cooling strategy is determined based on the operating mode of the hybrid drive system, which includes shifting an operating point of the engine.

[0029] In step 4, the cooling strategy is implemented until the exhaust gas temperature of the engine is lower than a second exhaust gas temperature protection threshold.

[0030] In this embodiment, if it is determined that the exhaust gas temperature of the engine is higher than the first exhaust gas temperature protection threshold, it is first determined whether the hybrid drive system is operating in series or parallel mode. Then, a corresponding cooling strategy, which includes shifting the engine's operating point, is determined based on the operating mode, and the execution of the cooling strategy is controlled until the engine's exhaust gas temperature is lower than the second exhaust gas temperature protection threshold. Compared to a related technique where exhaust gas temperature is reduced by fuel enrichment, this embodiment of the present application uses different cooling strategies, each involving shifting the engine's operating point, in the different operating modes (i.e., series and parallel modes, respectively).This effectively reduces the exhaust gas temperature of the engine, avoids fuel enrichment during the reduction of the exhaust gas temperature, and reduces the fuel consumption caused by fuel enrichment, thereby reducing the fuel consumption of the hybrid drive system and achieving energy savings and emission reductions. The aforementioned steps are described in detail below with reference to the accompanying drawings.

[0031] As in Fig. As shown in Figure 3, the exhaust gas temperature of the engine can first be obtained in various ways. Real-time monitoring of the exhaust gas temperature of the engine can be implemented, for example, by providing a temperature sensor, but this is not the only option. The temperature sensor could be, for example, a thermal resistance temperature sensor, a thermocouple temperature sensor, or the like, but these are not the only options.

[0032] For example, on Fig. 3 and Fig. 4. Reference is made to this. Each time the exhaust gas temperature of the engine is obtained, a determination is made as to whether the exhaust gas temperature of the engine is higher than the first exhaust gas temperature protection threshold. The first exhaust gas temperature protection threshold is determined taking into account factors such as the type of catalyst material or the maximum temperature that a turbocharger can withstand, but without limitation.

[0033] As in Fig. 3 and Fig. As shown in Figure 4, if the exhaust gas temperature of the engine is determined to be higher than the first exhaust gas temperature protection threshold, the hybrid drive system will be assigned a current operating mode. The operating mode includes series mode or parallel mode. A Fig. The operating status shown in Figure 4 is also referred to as the operating mode. This means that if the exhaust gas temperature of the engine is higher than the first exhaust gas temperature protection threshold, it is determined whether the current operating mode of the hybrid drive system is series mode or parallel mode.

[0034] As in Fig. As shown in Figure 3, the next step is to determine the cooling strategy, which involves shifting the operating point of the engine, based on the operating mode of the hybrid drive system. Fig. 5 is a diagram showing the exhaust gas temperature characteristics of the engine, with a horizontal axis in Fig. 5 represents an output speed of the power machine, and a vertical axis in Fig. 5 represents the output torque of the power unit. A first quadrant in Fig. Figure 5 shows the curve of an external property of the engine and isothermal distribution curves at 600 degrees Celsius, 750 degrees Celsius, and 950 degrees Celsius. It can be seen that the distribution of the engine's exhaust gas temperature is related to the engine's output speed and output torque, and that the engine's operating points are distributed across a low exhaust gas temperature range and a high exhaust gas temperature range. The higher the engine's output speed and the lower its output torque, the lower the exhaust gas temperature. Furthermore, in a hybrid drive system, the engine's operating point can be decoupled from the power demand for propelling the vehicle.More precisely, the operating point of the engine can be shifted by changing its output speed and / or output torque. In other words, it can be shifted by changing at least one of these output parameters (i.e., the engine's output speed and output torque) to effectively reduce the engine's exhaust temperature. Different balancing strategies for the power demand for propelling the vehicle can be employed based on the various operating modes, ensuring that the power supplied to the vehicle remains unchanged or as unchanged as possible, thereby reducing the impact of shifting the engine's operating point on the vehicle's tractive force.

[0035] When determining the cooling strategy, which involves shifting the operating point of the engine, based on the operating mode of the hybrid drive system, different types of cooling strategies are created, each involving a shift in the engine's operating point based on different operating modes of the hybrid drive system (i.e., series mode or parallel mode). Several methods for determining the cooling strategy are described below.

[0036] For example, it will be said that Fig. 4. The cooling strategy determined in response to the finding that the current operating mode of the hybrid drive system is series mode may include: increasing the output speed of the engine and decreasing the output torque of the engine while maintaining the series mode of the hybrid drive system. Reference is made to a diagram of the displacement of an engine's operating point, which is shown in Fig. Figure 6 shows that a filled star represents an operating point of the engine before the shift, where the engine's exhaust gas temperature is distributed along an isotherm at approximately 950 degrees. A white, unfilled star represents an operating point of the engine after the shift, where the engine's exhaust gas temperature is distributed along an isotherm at approximately 750 degrees. It can be seen that in the process of shifting the engine's operating point towards a higher output speed and lower output torque (in Fig. 6 in the direction to the lower right) the exhaust gas temperature of the engine can be significantly reduced even without the use of fuel enrichment.

[0037] In one embodiment, based on the type of shift in the operating point of the power machine, as in Fig. Figure 6 shows that while the output speed of the engine is increased and the output torque of the engine is decreased, the output power of the engine remains unchanged, so that the output power delivered by the engine to the generator remains unchanged. This allows the generator to produce power after the shift at approximately the same generator output as before the shift, so that a corresponding charging rate of the power battery and a ratio of the energy taken by the drive motor from the generator to the energy taken from the power battery both remain essentially unchanged.In this way, the power battery and the drive motor can be supplied with energy by the power machine after the shift, approximately corresponding to the output power before the shift of the power machine's operating point, and the driving force delivered to the vehicle's wheels by the hybrid drive system remains essentially unaffected.

[0038] It should be noted that in the aforementioned series mode, the method of shifting the operating point of the engine, by increasing the output speed of the engine and decreasing the output torque of the engine, is subject to the condition that the output power of the engine remains unchanged; however, this is not the only condition, and another condition may also be used. For example, the other condition may be that the output power of the engine after the shift can be appropriately reduced relative to the output power of the engine before the shift. In this case, a reduction in the energy supplied by the engine to the drive motor via the generator, resulting from the reduction in the engine's output power, is compensated for by the power battery supplying energy to the drive motor.This balancing continues until the exhaust gas temperature of the engine is reduced to the second exhaust gas temperature protection threshold, and then the output power of the engine is increased to charge the power battery via the generator.

[0039] For example, it will be said that Fig. 4. Reference is made to the following. If the operating mode of the hybrid drive system is parallel mode, the state of charge (State of Charge) of the power battery in the hybrid drive system can first be obtained when determining the cooling strategy. The State of Charge represents the state of charge of the power battery. If the State of Charge is relatively higher, this indicates that the remaining charge level is higher and immediate charging of the power battery is not necessary. If the State of Charge is relatively lower, this indicates that the remaining charge level is lower and charging of the power battery must be considered. Subsequently, the cooling strategy is determined based on the State of Charge, which includes reducing the output torque of the engine.This means that if the current operating mode of the hybrid drive system is the parallel mode, different cooling strategies can be used based on the charge levels of the power battery, but these different cooling strategies all involve a reduction in the output torque of the engine.

[0040] It will continue to be on Fig. 4. Reference is made to this. If the power battery's state of charge is greater than a state-of-charge protection threshold, this indicates that the power battery's state of charge is relatively higher, the remaining charge level is higher, and the power battery does not urgently need charging. The state-of-charge protection threshold can be determined based on factors such as the power battery's type and remaining service life. The cooling strategy determined in response to the finding that the power battery's state of charge is greater than the state-of-charge protection threshold may, for example, include reducing the output torque of the power unit while maintaining the hybrid drive system in parallel mode.This means that if the operating mode of the hybrid drive system is not changed, the output torque of the engine is reduced directly without changing the engine's output speed. Reference is made to a diagram of the displacement of an engine's operating point, which is shown in [reference missing]. Fig. Figure 7 shows that a filled star represents the operating point of the engine before the shift, where the engine's exhaust gas temperature is distributed on the isotherm at approximately 950 degrees. A white, unfilled star represents the operating point of the engine after the shift, where the engine's exhaust gas temperature is distributed on the isotherm at approximately 750 degrees. It can be seen that in the process of shifting the engine's operating point in the direction of the lower output torque of the engine (downward direction in the... Fig. 7) the exhaust gas temperature of the engine can be significantly reduced without the use of fuel enrichment.

[0041] Based on the type of shift in the operating point of the power machine, as in Fig. As shown in Figure 7, the cooling strategy determined in response to the finding that the power battery's state of charge exceeds the state-of-charge protection threshold may, for example, further include: compensating for a reduction in the torque delivered by the power unit to the vehicle's wheels by the drive motor in the hybrid drive system. It should be noted that in parallel mode, if the power unit's output torque is reduced, the torque delivered directly by the power unit to the vehicle's wheels, as part of the total drive torque of the vehicle's wheels, is also reduced, and this reduction in torque delivered directly by the power unit to the vehicle's wheels can be compensated for by the drive motor in the hybrid drive system.Additional energy used by the drive motor to compensate for the reduction in torque can be supplied by the power battery. This means that, following the reduction in the drive motor's output torque, the cooling strategy also reduces the torque directly delivered from the drive motor to the vehicle's wheels. This reduction can be compensated for by increasing the drive torque delivered by the drive motor to the vehicle's wheels, thus maintaining the vehicle's drive torque and ensuring that the cooling process does not impair the vehicle's normal operation.

[0042] It will continue to be on Fig. 4. Reference is made to the state of charge of the power battery. If the state of charge of the power battery is not greater than the state of charge protection threshold, this indicates that the remaining charge level of the power battery is relatively low and charging of the power battery must be considered. In this case, the specific cooling strategy may, for example, include: first switching the operating mode of the hybrid drive system from parallel mode to series mode, and then increasing the output speed and decreasing the output torque of the power engine while maintaining the series mode of the hybrid drive system.This means that if the state of charge of the power battery is relatively low, the operating mode of the hybrid drive system can first be switched from parallel mode to series mode. Then, in series mode, cooling is implemented using a cooling strategy that shifts the operating point of the engine, which involves increasing the engine's output speed and decreasing its output torque. The method for determining the cooling strategy after switching to series mode is essentially the same as when the hybrid drive system's operating mode is initially identified as the series mode described above. The difference between the two methods is that, in this embodiment, the transition to series mode occurs via a switch from parallel mode.

[0043] After switching the hybrid drive system's operating mode from parallel to series, while increasing the engine's output speed and decreasing its output torque, the engine's output power can be kept constant, thus maintaining the same output power delivered to the generator. This allows the generator to produce power after the shift at approximately the same output as before, so that the charging rate of the power battery and the ratio of energy drawn by the drive motor from the generator to energy drawn from the power battery both remain essentially unchanged.In this way, the power battery and the drive motor can be supplied with energy by the power unit after the shift in the power unit's operating point, approximately equivalent to the output power before the shift, and the driving force delivered to the vehicle's wheels by the hybrid drive system remains essentially unaffected. It should also be noted that in the aforementioned series mode, the method of shifting the power unit's operating point—by increasing the power unit's output speed and decreasing its output torque—is subject to the condition of keeping the power unit's output power unchanged, but is not limited to this condition, and other conditions can also be used.The other condition might be, for example, that the engine's output power after displacement can be suitably reduced relative to its output power before displacement. In this case, a reduction in the energy supplied by the engine to the drive motor via the generator, resulting from the reduction in the engine's output power, is compensated for by the power battery supplying energy to the drive motor. This compensation continues until the engine's exhaust temperature is reduced to the second exhaust temperature protection threshold, at which point the engine's output power is increased to charge the power battery via the generator.However, since the state of charge of the power battery is already relatively small (smaller than the state of charge protection threshold), the output power of the motor cannot be significantly reduced in this case.

[0044] For example, after determining the cooling strategy with reference to Fig. 3 and Fig. 4. The cooling strategy is executed until the engine's exhaust gas temperature is lower than the second exhaust gas temperature protection threshold, thereby reducing the engine's exhaust gas temperature. The second exhaust gas temperature protection threshold can be determined based on factors such as the engine's operating status, the engine's catalyst material, and / or the engine's turbocharger type. Since the second exhaust gas temperature protection threshold determines whether to exit the cooling strategy after it has been executed for a certain period, the first and second exhaust gas temperature protection thresholds can be different or the same.For example, the second exhaust gas temperature protection threshold can be the same as the first exhaust gas temperature protection threshold, or the second exhaust gas temperature protection threshold can be smaller than the first exhaust gas temperature protection threshold.

[0045] Among the various types described above, according to the control method and control device for the exhaust gas temperature of a power engine provided by the embodiments of the present application, when it is determined that the exhaust gas temperature of the power engine is higher than the first exhaust gas temperature protection threshold, it is first determined whether the current operating mode of the hybrid drive system is the series mode or the parallel mode, and then, based on different operating modes, corresponding cooling strategies are determined which include shifting the operating point of the power engine, and the cooling strategy is carried out until the exhaust gas temperature of the power engine is lower than the second exhaust gas temperature protection threshold.Compared to a related technique where exhaust gas temperature is reduced by fuel enrichment, this embodiment of the present application uses different cooling strategies, each involving a shift in the operating point of the engine, in the different operating modes (i.e., the series and parallel modes, respectively). This effectively reduces the exhaust gas temperature of the engine, avoids fuel enrichment during the exhaust gas temperature reduction, and reduces the fuel consumption caused by fuel enrichment, thereby reducing the fuel consumption of the hybrid drive system and achieving energy savings and emission reductions.

[0046] Furthermore, in one embodiment of the present application, a control device for the exhaust gas temperature of a power engine is also provided. The control method for the exhaust gas temperature of the power engine is applied to a hybrid drive system, wherein one operating mode of the hybrid drive system comprises a series mode and a parallel mode, which utilize hybrid electrical power. The control device comprises a storage medium and a processor. A computer program executable by the processor is stored on the storage medium. The processor is configured to perform one of the aforementioned control methods for the exhaust gas temperature of the power engine when the computer program is executed.When the hybrid drive system is applied to a vehicle, the exhaust gas temperature control device for the engine can be integrated into a vehicle control unit (VCU). Alternatively, a separate control device independent of the overall vehicle control system can be used.

[0047] Fig. Figure 8 is a block diagram of a control device for the exhaust gas temperature of a power engine according to an embodiment of the present application. As in Fig.As shown in Figure 8, the exhaust gas temperature control device 100 provided in this embodiment of the present application can comprise a storage medium 110 and a processor 120. A computer program executable by the processor 620 is stored on the storage medium 110. The processor 620 is configured to perform one of the aforementioned exhaust gas temperature control methods according to the embodiments of the present application when the computer program is executed by the processor 620. The specific operation of the exhaust gas temperature control device, which is provided in each embodiment of the present application in combination with the aforementioned description, is self-explanatory to those skilled in the art. For the sake of brevity, details are not repeated here.

[0048] Furthermore, in one embodiment of the present application, a storage medium is also provided. A computer program is stored on the storage medium. When the computer program is executed, one of the aforementioned control methods for the exhaust gas temperature of the engine is carried out. The storage medium is readable by a processor. For example, the storage medium may comprise: a memory card of a smartphone, a memory component of a tablet computer, a hard drive of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disc read-only memory (CD-ROM), a USB flash drive, or any combination of the aforementioned storage media.

[0049] Furthermore, in one embodiment of the present application, a computer program is also provided. This computer program is configured, when executed by a processor, to perform the corresponding steps of the control procedure for the exhaust gas temperature of the engine in one of the aforementioned embodiments of this application.

[0050] Furthermore, in one embodiment of this application, a hybrid drive system is provided. An operating mode of the hybrid drive system comprises a series mode and a parallel mode, both utilizing hybrid electrical power. The hybrid drive system also includes a control device for the exhaust gas temperature of the engine, which monitors the exhaust gas temperature of the engine in real time and, in response to determining whether the operating mode is series or parallel, employs a cooling strategy that includes shifting the operating point of the engine when the exhaust gas temperature of the engine exceeds the first exhaust gas temperature protection threshold.This effectively reduces the exhaust gas temperature of the engine, avoids fuel enrichment during the reduction of the exhaust gas temperature, and reduces the fuel consumption caused by fuel enrichment, thereby reducing the fuel consumption of the hybrid drive system and achieving the effect of energy saving and emission reduction.

[0051] For example, the hybrid drive system is a hybrid drive system arranged on the body of a vehicle. The vehicle can be, in particular, for example, a passenger car, a truck, or a special construction vehicle, but without limitation. The vehicle body comprises structures such as a vehicle frame, vehicle wheels, a transmission, and a steering wheel. One of the aforementioned hybrid drive systems is arranged on the vehicle body. Compared to a related technique in which exhaust gas temperature is reduced by fuel enrichment, in an embodiment of the present application, the vehicle is provided which, upon observation that the exhaust gas temperature of the engine is higher than the first exhaust gas temperature protection threshold, employs different cooling strategies, each involving a shift in the operating point of the engine, in the operating modes (i.e.,This can be used in series mode or parallel mode. This effectively reduces the exhaust gas temperature of the engine, avoids fuel enrichment during the reduction of the exhaust gas temperature, and reduces fuel consumption caused by fuel enrichment, thereby reducing the vehicle's fuel consumption and achieving energy savings and emission reductions.

[0052] Furthermore, in one embodiment of the present application, a vehicle is provided. The vehicle comprises: a vehicle body and one of the aforementioned hybrid drive systems arranged on the vehicle body. In particular, the vehicle can be, for example, a passenger car, a truck, or a special construction vehicle, but without limitation. The vehicle body comprises structures such as a vehicle frame, vehicle wheels, a transmission, and a steering wheel. One of the aforementioned hybrid drive systems is arranged on the vehicle body.Compared to a related technique where exhaust gas temperature is reduced by fuel enrichment, in one embodiment of this application the vehicle is provided which, upon observing that the exhaust gas temperature of the engine is higher than the first exhaust gas temperature protection threshold, can employ different cooling strategies, including shifting the operating point of the engine, in the operating modes (i.e., series mode and parallel mode, respectively). This effectively reduces the exhaust gas temperature of the engine, avoids fuel enrichment during the reduction of the exhaust gas temperature, and reduces the fuel consumption caused by fuel enrichment, thereby reducing the vehicle's fuel consumption and achieving the effects of energy savings and emission reduction.

[0053] The present application has been described with reference to the aforementioned embodiments. However, it should be noted that the aforementioned embodiments serve only for illustration and description and are not intended to limit the present application to the described embodiments. Furthermore, it is obvious to those skilled in the art that the present application is not limited to the aforementioned embodiments. Numerous variants and modifications can be developed based on the teaching of the present application, and these variants and modifications all fall within the scope of protection of the present application. The scope of protection of the present application is defined by the attached claims and their equivalents. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CH 202310493167.5

[0001]

Claims

[1] Control method for an exhaust gas temperature of a power engine, characterized by , that the control method is applied to a hybrid drive system, wherein an operating mode of the hybrid drive system has a series mode and a parallel mode, utilizing hybrid electrical power, and the control method comprises the following steps: Maintaining the exhaust gas temperature of the engine; Maintaining the operating mode of the hybrid drive system when the exhaust gas temperature of the engine is higher than a first exhaust gas temperature protection threshold, wherein the operating mode is either series mode or parallel mode; Determining a cooling strategy that involves shifting the operating point of the engine, based on the operating mode of the hybrid drive system; and Controls to implement the cooling strategy until the exhaust gas temperature of the engine is lower than a second exhaust gas temperature protection threshold. [2] Control method according to claim 1, wherein determining the cooling strategy, which includes shifting the operating point of the power machine, based on the operating mode of the hybrid drive system comprises the following step: Determining the cooling strategy in response to the determination that the operating mode of the hybrid drive system is the series mode, wherein the cooling strategy comprises: increasing an output speed of the power machine and decreasing an output torque of the power machine, under a condition where the series mode is maintained unchanged as the operating mode. [3] Control method according to one of claims 1 and 2, wherein determining the cooling strategy, which includes shifting the operating point of the engine, based on the operating mode of the hybrid drive system comprises the following steps: Obtaining a state-of-charge value of a power battery in the hybrid drive system in response to the determination that the operating mode of the hybrid drive system is parallel mode; and Determining a cooling strategy that reduces the output torque of the power unit, based on the state of charge of the power battery. [4] Control method according to claim 3, wherein determining the cooling strategy, which includes reducing the output torque of the power machine, based on the state of charge of the power battery comprises the following step: In response to determining that the state of charge of the power battery is greater than a state of charge protection threshold, determining the cooling strategy, wherein the cooling strategy comprises: reducing the output torque of the power machine under a condition where the parallel mode is maintained unchanged as the operating mode. [5] Control method according to claim 4, wherein determining the cooling strategy in response to the determination that the state of charge of the power battery is greater than the state of charge protection threshold comprises the following step: Compensating for a reduction in the output torque delivered to a vehicle by the engine, by a drive motor in the hybrid drive system. [6] Control method according to any one of claims 3 to 5, wherein determining the cooling strategy, which includes reducing the output torque of the power machine, based on the state of charge of the power battery comprises the following step: Determining the cooling strategy in response to the finding that the state of charge of the power battery is not greater than the state of charge protection threshold, wherein the cooling strategy comprises the following steps: Switching the operating mode of the hybrid drive system from parallel mode to serial mode and Increasing the output speed of the power machine and decreasing the output torque of the power machine. [7] Control method according to any one of claims 2 to 6, wherein the output power of the engine is kept unchanged while the output speed of the engine is increased and the output torque of the engine is reduced. [8] Control device for an exhaust gas temperature of a power engine, characterized by that the control device is applied to a hybrid drive system, wherein an operating mode of the hybrid drive system has a serial mode and a parallel mode, utilizing hybrid electrical power, wherein the control device has a storage medium and a processor, on the storage medium a computer program executable by the processor is stored, and the processor is configured to perform the control method for the exhaust gas temperature of the engine according to one of claims 1 to 7 when the computer program is executed by the processor. [9] Hybrid drive system, characterized by, that an operating mode of the hybrid drive system comprises a series mode and a parallel mode that uses hybrid electrical power; and the hybrid drive system comprises the control device for the exhaust gas temperature of the engine according to claim 8. [10] vehicle, characterized by , that the vehicle has the following features: a vehicle body and the hybrid drive system arranged on the vehicle body according to claim 9.

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