Electric auxiliary turbocharging system, control method and vehicle

Abstract

The invention discloses an electric auxiliary turbocharging system, a control method and a vehicle, and the electric auxiliary turbocharging system comprises a pressing wheel, an electric auxiliary turbocharging device and a control device, wherein the pressing wheel is arranged in an air inlet pipe of an engine; the turbine is arranged in an exhaust pipe of the engine; the pressing wheel and the turbine are connected through the differential mechanism, and the differential mechanism and the pressing wheel are dynamically coupled or decoupled; the differential mechanism and the turbine are dynamically coupled or decoupled; the motor is connected with the pressing wheel and the turbine through the differential mechanism, and the motor is configured to be capable of adjusting the transmission ratio through the differential mechanism or transmitting power between the motor and the pressing wheel or the turbine through the differential mechanism.

Description

Technical Field

[0001] The present invention relates to the field of vehicle power technology, and in particular to an electric-assisted turbocharging system and a control method, and a vehicle. Background Art

[0002] Engine supercharging is to increase the density of engine intake air, thereby achieving an increase in engine power density and engine miniaturization. Currently, the main types of supercharging used in engines are turbocharging, mechanical supercharging and electric supercharging.

[0003] In the related technology, the existing engine supercharging system combines three power devices: engine, motor and exhaust gas turbine. It can provide the fastest power response speed in the full speed range of the engine and promote the full combustion of fuel in the cylinder. However, there are the following problems: the brake and clutch are used for speed coupling / decoupling operation. The clutch engagement and disconnection during operation will cause serious mechanical wear, vibration noise and vehicle frustration. In addition, the exhaust bypass valve is designed for high-load conditions to prevent engine overheating and overspeeding, but this will result in a loss of some exhaust energy. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes an electrically assisted turbocharging system, in which the compressor wheel and the turbine are connected via a differential mechanism and the motor is connected to the differential mechanism, and the differential mechanism is used to perform speed coupling / decoupling operations, which can effectively improve the turbine hysteresis, and the motor can be used to completely recover the energy in the turbine during speed coupling, and the waste gas bypass valve can be eliminated to improve the thermal efficiency.

[0005] The present invention further proposes a control method for an electrically assisted turbocharger system.

[0006] The present invention further provides a vehicle.

[0007] According to an embodiment of the first aspect of the present invention, the electrically assisted turbocharger system includes: a pressure wheel, which is arranged in the intake pipe of the engine; a turbine, which is arranged in the exhaust pipe of the engine; a differential mechanism, through which the pressure wheel and the turbine are connected, and the differential mechanism and the pressure wheel are dynamically coupled or decoupled; and the differential mechanism and the turbine are dynamically coupled or decoupled; a motor, which connects the pressure wheel and the turbine through the differential mechanism, and is configured so that the motor can adjust the transmission ratio through the differential mechanism or the motor can transmit power between the differential mechanism and the pressure wheel or the turbine.

[0008] According to the electrically assisted turbocharger system of the embodiment of the present invention, the differential mechanism is used to perform power decoupling and power coupling on the compressor and turbine. First, the motor and the differential mechanism can be used to adjust the transmission ratio between the compressor and the turbine to ensure that the turbine and the compressor always work in a high-efficiency condition, which not only improves the exhaust energy utilization rate, but also effectively avoids the loss in the process of converting mechanical energy into electrical energy. Second, the motor can be used to replenish the compressor or recover the mechanical energy in the turbine in real time according to the intake and exhaust energy. Third, the turbine and compressor speeds can be decoupled and independently controlled by the differential mechanism, and the compressor speed and pressure can be quickly increased by the motor, which can not only effectively improve the turbine hysteresis, but also increase the engine power and reduce emissions. The motor can also be used to recover the energy in the turbine, eliminate the wastegate valve, and improve the thermal efficiency, so that the electrically assisted turbocharger system can meet the engine needs in a timely manner.

[0009] According to some embodiments of the present invention, the electrically assisted turbocharger system further includes: a locking mechanism, which is provided between the differential mechanism and the pressure wheel and between the differential mechanism and the turbine, and is used to selectively disconnect the power coupling between the differential mechanism and the pressure wheel or the power coupling with the turbine.

[0010] According to some embodiments of the present invention, the differential mechanism includes: a sun gear, the turbine is connected to the sun gear through a turbine shaft; a planetary carrier, the pressure wheel is connected to the planetary carrier through a pressure wheel shaft; a planetary ring gear, the inner side of the planetary ring gear is meshed with the planetary gear on the planetary carrier, the outer side of the planetary ring gear is meshed with the gear of the motor, and the output end of the motor is connected to the gear transmission.

[0011] According to the control method of the electrically assisted turbocharger system of the second aspect of the present invention, the control method is used to control the electrically assisted turbocharger system, and the control method includes: when the engine is in the normal operating stage, starting the motor, the differential mechanism is dynamically coupled with the pressure wheel and the turbine, and the motor adjusts the transmission ratio through the differential mechanism; or drives the pressure wheel to boost or recover mechanical energy in the turbine through the differential mechanism.

[0012] According to some embodiments of the present invention, the control method further includes: obtaining the power demand of the engine; if the power demand of the engine is higher than a threshold value, the motor drives the pressure wheel to increase pressure or recover mechanical energy in the turbine through the differential mechanism; if the power demand of the engine is lower than a threshold value, the motor adjusts the transmission ratio through the differential mechanism.

[0013] According to some embodiments of the present invention, if the power demand of the engine is lower than a threshold value, it further includes: obtaining the difference between exhaust energy and intake energy; if the power demand of the engine is lower than a threshold value and the difference between exhaust energy and intake energy is higher than a second threshold value, the motor drives the compression wheel to boost or recover mechanical energy in the turbine through the differential mechanism; if the power demand of the engine is lower than a threshold value and the difference between exhaust energy and intake energy is lower than a second threshold value, the motor adjusts the transmission ratio through the differential mechanism.

[0014] According to some embodiments of the present invention, if the power demand of the engine is lower than a first threshold and the difference between the exhaust energy and the intake energy is lower than a second threshold, the motor adjusts the transmission ratio through the differential mechanism, further comprising: obtaining the intake flow and intake pressure of the intake pipe and the exhaust flow and exhaust pressure of the exhaust pipe; determining the target economic speed of the compressor and the turbine based on the intake flow, exhaust flow, intake pressure and exhaust pressure; and controlling the motor to adjust the transmission ratio of the differential mechanism based on the target economic speed of the compressor and the turbine to match the compressor and the turbine to the target economic speed.

[0015] According to some embodiments of the present invention, the method of obtaining the difference between the exhaust energy and the intake energy includes: obtaining the pressure and temperature of the intake pipe and the exhaust pipe respectively and the rotation speed of the compressor wheel and the turbine, determining the intake energy and the exhaust energy, and calculating the difference between the intake energy and the exhaust energy.

[0016] According to some embodiments of the present invention, obtaining the power demand of the engine includes: obtaining a depth signal of the vehicle's accelerator pedal to determine the total power demand; obtaining a battery capacity signal to determine the power demand of the battery, and determining the power demand of the engine based on the total power demand and the power demand of the battery.

[0017] According to some embodiments of the present invention, if the power demand of the engine is higher than a threshold value, the motor drives the compressor to boost or recover the mechanical energy of the turbine through the differential mechanism, further including: obtaining intake energy and exhaust energy; if the exhaust energy is greater than the intake energy, the motor recovers the mechanical energy in the turbine through the differential mechanism; if the exhaust energy is lower than the intake energy, the motor drives the compressor to boost through the differential mechanism.

[0018] According to some embodiments of the present invention, the control method further includes: when the engine is in a cold start stage, starting the motor, the differential mechanism is dynamically decoupled from the turbine and dynamically coupled to the pressure wheel, and the motor drives the pressure wheel to boost pressure through the differential mechanism; when the engine is in an overheating stage, starting the motor, the differential mechanism is dynamically decoupled from the pressure wheel and dynamically coupled to the turbine, and the motor recovers mechanical energy in the turbine through the differential mechanism.

[0019] According to some embodiments of the present invention, the control method further includes: receiving an engine start request signal to start the engine; obtaining the engine's cooling water temperature, exhaust pipe temperature and lubricating oil temperature to determine whether the engine is in a cold state or a warm state; if in a cold state, controlling the engine to enter a cold start phase until the engine operates normally; if in a warm state, determining whether the engine is in an overheated state, and if so, controlling the engine to enter an overheated phase until the engine operates normally; if not, controlling the engine to enter a normal operating phase.

[0020] According to some embodiments of the present invention, the control method further includes: judging whether the engine needs to continue running according to the needs of the whole vehicle; if it needs to continue running, re-judging whether the engine is in an overheating state; if it needs to be shut down, executing a shutdown command by cutting off the engine injection signal, and recovering the mechanical energy in the turbine through the motor.

[0021] A vehicle according to an embodiment of the third aspect of the present invention includes the control method of the electrically assisted turbocharger system.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 is a schematic structural diagram of an electrically assisted turbocharger system according to an embodiment of the present invention; Figure 2 is a control logic diagram of an electrically assisted turbocharger system according to an embodiment of the present invention; Figure 3 is a schematic diagram of energy flow when an electrically assisted turbocharger system enters a speed regulation mode according to an embodiment of the present invention; Figure 4 is a schematic diagram of energy flow when an electrically assisted turbocharger system enters an energy replenishment mode according to an embodiment of the present invention; Figure 5is a schematic diagram of energy flow when an electrically assisted turbocharger system enters a regenerative mode according to an embodiment of the present invention; Figure 6 is a schematic diagram of energy flow when an electrically assisted turbocharger system enters a cold start mode according to an embodiment of the present invention; Figure 7 Schematic diagram of energy flow when an electrically assisted turbocharger system enters an overheat protection mode according to an embodiment of the present invention.

[0024] Reference numerals: 1. Pressure wheel; 2. Intake pipe; 3. Turbine; 4. Exhaust pipe; 5. Differential mechanism; 501. Sun gear; 502. Planet carrier; 503. Planetary ring gear; 504. Planetary gear; 505. Outer ring gear; 6. Motor; 601. Gear; 7. Locking mechanism; 8. Pressure wheel shaft; 9. Turbine shaft. DETAILED DESCRIPTION

[0025] Embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. Embodiments of the present invention are described in detail below.

[0026] Reference below Figure 1-Figure 7 An electrically assisted turbocharging system and a control method according to an embodiment of the present invention are described.

[0027] like Figure 1 As shown, the electrically assisted turbocharger system includes: a compressor wheel 1, a turbine 3, a differential mechanism 5 and a motor 6. The compressor wheel 1 is arranged in the intake pipe 2 of the engine, and the turbine 3 is arranged in the exhaust pipe 4 of the engine. The compressor wheel 1 and the turbine 3 are connected through the differential mechanism 5. The differential mechanism 5 and the compressor wheel 1 are dynamically coupled or decoupled, and the differential mechanism 5 and the turbine 3 are dynamically coupled or decoupled. The motor 6 connects the compressor wheel 1 and the turbine 3 through the differential mechanism 5. The motor 6 is configured so that the motor 6 can adjust the transmission ratio through the differential mechanism 5 or the motor 6 can transmit power between the compressor wheel 1 or the turbine 3 through the differential mechanism 5.

[0028] Specifically, the differential mechanism 5 can be dynamically coupled or dynamically decoupled from the pressure wheel 1 and the turbine 3, thereby forming four combinations, as follows: The first type is that the differential mechanism 5 is power-coupled with the pressure wheel 1 and the turbine 3, so that the motor 6 can transmit power to the pressure wheel 1 and the turbine 3 through the differential mechanism 5 and adjust the transmission ratio between the pressure wheel 1 and the turbine 3 through the differential mechanism 5.

[0029] The second type is that the differential mechanism 5 is dynamically coupled to the pressure wheel 1 and dynamically decoupled from the turbine 3 , so that the motor 6 can transmit power to the pressure wheel 1 through the differential mechanism 5 .

[0030] The third type is that the differential mechanism 5 is power-decoupled from the pressure wheel 1 and power-coupled with the turbine 3 , so that the motor 6 can transmit power between the differential mechanism 5 and the turbine 3 .

[0031] In the fourth type, the differential mechanism 5 is dynamically decoupled from the pressure wheel 1 and the turbine 3, so the motor 6, the pressure wheel 1 and the turbine 3 are mutually decoupled, and power transmission cannot be achieved among the three.

[0032] Among them, in the first form, refer to Figure 3 As shown in the energy flow diagram, the mechanical energy in the turbine 3 can be transmitted to the compressor wheel 1 through the differential mechanism 5 to realize the supercharging and air supply of the compressor wheel 1, and the transmission ratio of the differential mechanism 5 can be adjusted by the motor 6. The rotational speeds of the turbine 3 and the compressor wheel 1 can be coupled at a certain speed ratio to efficiently transmit the mechanical energy, so that the turbine 3 and the compressor wheel 1 always work in a high-efficiency working condition, which not only improves the exhaust energy utilization rate, but also effectively avoids the loss in the process of converting mechanical energy into electrical energy.

[0033] And, refer to Figure 4 As shown in the energy flow diagram, during the process of the turbine 3 supercharging the pressure wheel 1, if the turbine 3 is not sufficient to provide sufficient mechanical energy to the pressure wheel 1, the motor 6 can be used to supercharge the pressure wheel 1; and, referring to Figure 5 As shown in the energy flow diagram, during the process of the turbine 3 supercharging the compressor wheel 1, if the mechanical energy provided by the turbine 3 exceeds the energy required by the compressor wheel 1, the motor 6 can be used to recover the mechanical energy in the turbine 3, thereby effectively improving the transient response capability.

[0034] In the second form, refer to Figure 6 As shown in the energy flow diagram, the speeds of the turbine 3 and the compressor wheel 1 can be decoupled and independently controlled through the differential mechanism 5, and the speed and pressure of the compressor wheel 1 can be quickly increased through the motor 6 to achieve pressurization and air supply to the compressor wheel 1, which can not only effectively improve the hysteresis of the turbine 3, but also increase the engine power and effectively reduce emissions.

[0035] In the third form, refer to Figure 7 As shown in the energy flow diagram, the speeds of the turbine 3 and the compressor 1 can be decoupled and independently controlled through the differential mechanism 5. When the engine is in high-power and high-speed conditions, once the risk of engine overheating is detected, the energy in the turbine 3 can be recovered through the motor 6, thereby eliminating the exhaust bypass valve and improving thermal efficiency.

[0036] In addition, compared with the existing electric-assisted supercharger solution, the motor 6 can be arranged away from the turbine 3, which can effectively avoid the heat damage problem caused by the turbine 3.

[0037] According to the electric-assisted turbocharger system of the present invention, the differential mechanism 5 is used to decouple and couple the compressor 1 and the turbine 3. First, the motor 6 and the differential mechanism 5 can be used to adjust the transmission ratio between the compressor 1 and the turbine 3 to ensure that the turbine 3 and the compressor 1 always work in a high-efficiency working condition, which not only improves the exhaust energy utilization rate, but also effectively avoids the loss in the process of mechanical energy and electrical energy conversion. Second, the motor 6 can be used to replenish the compressor 1 or recover the mechanical energy in the turbine 3 in real time according to the intake and exhaust energy. Third, the speed of the turbine 3 and the compressor 1 can be decoupled and independently controlled by the differential mechanism 5. The speed and pressure of the compressor 1 can be quickly increased by the motor 6, which not only effectively improves the hysteresis of the turbine 3, but also increases the engine power and reduces emissions. The energy in the turbine 3 can also be recovered by the motor 6, the wastegate valve can be cancelled, and the thermal efficiency can be improved, so that the electric-assisted turbocharger system can meet the engine needs in a timely manner.

[0038] According to some embodiments of the present invention, the electrically assisted turbocharger system further includes: a locking mechanism 7, wherein a locking mechanism 7 is provided between the differential mechanism 5 and the pressure wheel 1 and between the differential mechanism 5 and the turbine 3, for selectively disconnecting the power coupling between the differential mechanism 5 and the pressure wheel 1 or the power coupling with the turbine 3.

[0039] Specifically, the pressure wheel 1 is connected to the pressure wheel shaft 8, the pressure wheel shaft 8 is connected to the differential mechanism 5, and a locking mechanism 7 is installed between the pressure wheel shaft 8 and the differential mechanism 5. In addition, the pressure wheel shaft 8 is installed on a one-way bearing to prevent reverse rotation. Similar to the pressure wheel 1, the turbine 3 is connected to the turbine shaft 9, the turbine shaft 9 is connected to the differential mechanism 5, and a locking mechanism 7 is installed between the turbine shaft 9 and the differential mechanism 5. In addition, the turbine shaft 9 is installed on a one-way bearing to prevent reverse rotation.

[0040] When the locking mechanism 7 locks the turbine shaft 9, Figure 6 As shown, the power coupling between the differential mechanism 5 and the turbine 3 is disconnected. At this time, the motor 6 transmits power to the compression wheel 1 through the differential mechanism 5, that is, the motor 6 can drive the compression wheel 1 to increase pressure and replenish air.

[0041] When the locking mechanism 7 locks the pressure wheel shaft 8, Figure 7 As shown, the power coupling between the differential mechanism 5 and the pressure wheel 1 is disconnected. At this time, the motor 6 transmits power to the pressure wheel 1 through the differential mechanism 5, that is, the motor 6 can recover the mechanical energy in the turbine 3.

[0042] Therefore, the locking mechanism 7 can decouple the rotational speeds of the compression wheel 1 and the turbine 3 through the differential mechanism 5 and can control them independently.

[0043] According to one embodiment of the present invention, the differential mechanism 5 may include: a sun gear 501, a planetary carrier 502 and a planetary ring gear 503, the turbine 3 is connected to the sun gear 501 through a turbine shaft 9, the pressure wheel 1 is connected to the planetary carrier 502 through a pressure wheel shaft 8, the inner side of the planetary ring gear 503 is meshed with the planetary gear 504 on the planetary carrier 502, the outer side of the planetary ring gear 503 is meshed with the gear 601 of the motor 6, and the output end of the motor 6 is transmission connected to the gear 601.

[0044] An outer gear ring 505 is installed outside the planetary gear ring 503 , and the outer gear ring 505 is meshed with the gear 601 of the motor 6 .

[0045] Of course, the differential mechanism 5 includes but is not limited to the above-mentioned planetary gear 601 system, and can also be replaced by other mechanical structures with differential / speed regulation functions.

[0046] The control method of the electric-assisted turbocharger system according to the second embodiment of the present invention is used to control the electric-assisted turbocharger system. The control method specifically includes: when the engine is in the normal operation stage, the motor 6 is started, the differential mechanism 5 is power-coupled with the pressure wheel 1 and the turbine 3, and the motor 6 adjusts the transmission ratio through the differential mechanism 5; or drives the pressure wheel 1 to boost or recover the mechanical energy in the turbine 3 through the differential mechanism 5.

[0047] See Figure 2 As shown, when the engine is in normal operation, the motor 6 is started to control the differential mechanism 5 to couple the pressure wheel 1 and the turbine 3. Figure 3 As shown in the energy flow diagram, the motor 6 can be used to adjust the transmission ratio of the differential mechanism 5 so that the compressor 1 and the turbine 3 are coupled at a certain speed ratio to efficiently transmit mechanical energy and avoid losses in the process of converting mechanical energy into electrical energy. The motor 6 can adjust the transmission ratio in real time so that the turbine 3 and the compressor 1 always work in an efficient working condition, thereby improving the exhaust energy utilization rate. Figure 4 and Figure 5 As shown in the energy flow diagram, the motor 6 can also be used to replenish the compressor 1 in real time according to the intake and exhaust energy difference / recover the mechanical energy in the turbine 3 to feed it back to the battery. Therefore, this control method can ensure that the electric-assisted turbocharger system can meet the engine demand in a timely manner.

[0048] According to some embodiments of the present invention, for the above three energy flow modes, the control method further includes: Get the power requirement of the engine; If the power demand of the engine is higher than a threshold value, the motor 6 drives the compression wheel 1 through the differential mechanism 5 to increase pressure or recover mechanical energy in the turbine 3; If the power demand of the engine is lower than a certain threshold value, the electric machine 6 adjusts the transmission ratio through the differential mechanism 5 .

[0049] With such a configuration, when the power demand of the engine is higher than a threshold value, that is, the power demand is relatively large, the motor 6 selectively drives the compressor 1 to boost pressure according to the difference between the intake energy and the exhaust energy, that is, enters the energy replenishment mode, or selectively recovers the mechanical energy in the turbine 3, that is, enters the feedback mode. When the power demand of the engine is lower than a threshold value, that is, the power demand is relatively small, the motor 6 can adjust the transmission ratio so that the compressor 1 and the turbine 3 are coupled at a certain speed ratio to efficiently transfer mechanical energy, that is, enter the speed regulation mode.

[0050] It is understandable that one type of threshold may include state parameters of the vehicle's real-time operation, such as the discharge power of the battery, the throttle opening controlled by the accelerator pedal, or the accelerator pedal depth, and other closed-loop feedback parameters.

[0051] According to some embodiments of the present invention, if the power demand of the engine is lower than a threshold value, the method further comprises: Obtaining the difference between exhaust energy and intake energy; If the power demand of the engine is lower than a first threshold value, and the difference between the exhaust energy and the intake energy is higher than a second threshold value, the motor 6 drives the compressor 1 through the differential mechanism 5 to boost pressure or recover mechanical energy in the turbine 3; If the power demand of the engine is lower than a first threshold value, and the difference between the exhaust energy and the intake energy is lower than a second threshold value, the motor 6 adjusts the transmission ratio through the differential mechanism 5 .

[0052] That is to say, on the basis that the power demand of the engine is lower than a threshold value, different working modes are determined according to the difference between the exhaust energy and the intake energy. Specifically, when the difference between the exhaust energy and the intake energy is higher than the second threshold value, it means that the energy difference is large, and it is necessary to enter the energy replenishment mode or the feedback mode. When the difference between the exhaust energy and the intake energy is lower than the second threshold value, the energy difference is small, and the speed regulation mode can be entered, and the transmission ratio can be adjusted in real time by the motor 6, so that the turbine 3 and the compressor wheel 1 always work in a high-efficiency condition, thereby improving the exhaust energy utilization rate.

[0053] According to some embodiments of the present invention, if the power demand of the engine is lower than a first threshold and the difference between the exhaust energy and the intake energy is lower than a second threshold, the motor 6 adjusts the transmission ratio through the differential mechanism 5, further comprising: Obtaining the intake flow rate and intake pressure of the intake pipe 2 and the exhaust flow rate and exhaust pressure of the exhaust pipe 4; Determine the target economic speed of the compressor 1 and the turbine 3 based on the intake flow rate, the exhaust flow rate, the intake pressure, and the exhaust pressure; Based on the target economic speed of the impeller 1 and the turbine 3 , the control motor 6 adjusts the transmission ratio of the differential mechanism 5 to match the impeller 1 and the turbine 3 to the target economic speed.

[0054] That is to say, after entering the speed regulation mode, the speed ratio is adjusted by the motor 6 to match the turbine 3 compressor 1 to the target economic speed. Specifically, the efficiency map of the compressor 1 and the turbine 3 is searched in combination with the intake flow and exhaust flow, intake pressure and exhaust pressure to determine the most economical speed range, and finally the speed ratio is adjusted by the motor 6 to match the turbine 3 compressor 1 to the target economic speed.

[0055] In the speed regulation mode, the energy of the pressure wheel 1 is mainly provided by the turbine 3, and the mechanical energy of the turbine 3 is transmitted to the pressure wheel 1 through the differential mechanism 5. The energy transmission efficiency is significantly higher than the three-stage transmission of "mechanical energy-electrical energy-mechanical energy". The motor 6 does not directly provide energy in this mode, and only consumes a small amount of energy to adjust the transmission ratio.

[0056] Moreover, the intake flow rate of the intake pipe 2 can be calculated by obtaining parameters such as the temperature, pressure, and rotation speed of the compression wheel 1 of the intake pipe 2, and the exhaust flow rate of the exhaust pipe 4 can be calculated by obtaining parameters such as the temperature, pressure, and rotation speed of the compression wheel 1 of the exhaust pipe 4. Among them, a speed sensor, a temperature sensor, and a pressure sensor are respectively arranged in the intake pipe 2 and the exhaust pipe 4.

[0057] Therefore, compared with the existing technical solution of electric supercharger plus electric turbine 3, the control method of the present invention can couple the rotation speed of turbine 3 and compressor 1 at a certain speed ratio to efficiently transmit mechanical energy and avoid loss in the process of converting mechanical energy into electric energy. In addition, the present invention proposes a solution for adjusting the transmission ratio in real time, using motor 6 to adjust the transmission ratio in real time, so that turbine 3 and compressor 1 always work in high-efficiency working conditions, thereby improving exhaust energy utilization.

[0058] According to some embodiments of the present invention, obtaining the difference between exhaust energy and intake energy includes: obtaining the pressure and temperature of the intake pipe 2 and the exhaust pipe 4, respectively, and the rotation speeds of the compressor wheel 1 and the turbine 3, determining the intake energy and the exhaust energy, and calculating the difference between the intake energy and the exhaust energy.

[0059] That is, the intake energy requirement and the exhaust energy are calculated through the respective pressure sensors and temperature sensors in the intake pipe 2 and the exhaust pipe 4, in combination with the rotation speeds of the compressor wheel 1 and the turbine 3, so as to obtain the energy difference.

[0060] According to some embodiments of the present invention, obtaining the power demand of the engine includes: Obtaining a depth signal of an accelerator pedal of the vehicle to determine a total power demand; Obtain battery capacity signal to determine battery power requirements, Based on the total power demand and the power demand of the battery, the power demand of the engine is determined.

[0061] It is understandable that, when the total power demand is determined, the power demand of the engine is obtained by subtracting the discharge demand of the battery. The above-mentioned accelerator pedal depth signal and battery capacity signal are necessary closed-loop feedback parameters for determining the engine power demand. Of course, other closed-loop feedback parameters can also be guaranteed.

[0062] According to some embodiments of the present invention, if the power demand of the engine is higher than a threshold value, the motor 6 drives the compressor 1 to boost pressure or recover mechanical energy in the turbine 3 through the differential mechanism 5, further comprising: Obtain intake energy and exhaust energy; If the exhaust energy is greater than the intake energy, the motor 6 recovers the mechanical energy in the turbine 3 through the differential mechanism 5; If the exhaust energy is lower than the intake energy, the motor 6 drives the compression wheel 1 to increase the pressure through the differential mechanism 5.

[0063] That is to say, after entering the energy replenishment mode / recharge mode, the energy replenishment / recharge mode of the motor 6 is determined according to the intake energy requirement and the exhaust energy. If the exhaust energy is higher than the intake energy required, the motor 6 applies a load to recover the excess mechanical energy to the battery, such as Figure 5 If the exhaust energy is lower than the energy required for intake, the motor 6 applies power to provide additional mechanical energy for the compression wheel 1 to increase the pressure and replenish air, as shown in FIG. Figure 4 In this energy replenishment / regeneration mode, the motor 6 is responsible for peak load shaving and valley filling, consuming electrical energy to ensure the transient response performance of the turbine 3 when the supply is insufficient to meet the demand, and recovering excess kinetic energy to the battery when the supply is excessive to meet the demand.

[0064] According to some embodiments of the present invention, the control method further comprises: When the engine is in the cold start stage, the motor 6 is started, the differential mechanism 5 is decoupled from the turbine 3, and is coupled to the pressure wheel 1, and the motor 6 drives the pressure wheel 1 to increase pressure through the differential mechanism 5; When the engine is in the overheating stage, the motor 6 is started, the differential mechanism 5 is dynamically decoupled from the pressure wheel 1 , and dynamically coupled to the turbine 3 , and the motor 6 recovers the mechanical energy in the turbine 3 through the differential mechanism 5 .

[0065] Specifically, see Figure 6 As shown, after entering the cold start mode, the engine speed cannot be increased quickly due to the cooling water temperature and oil temperature limits, so it is necessary to increase the torque to increase the engine power, so as to speed up the warm-up speed. The engine exhaust energy is low during the cold start stage, and it is difficult to drive the turbine 3 to generate enough speed for intake. For this reason, the turbine shaft 9 is locked by the locking mechanism 7 and the compression wheel 1 is directly driven by the motor 6 to increase the pressure and replenish air. After the air is replenished, the power of the engine during the cold start stage can be greatly increased. At this time, the engine fuel consumption and emissions are low, and the warm-up rate is fast.

[0066] See Figure 7 As shown, after entering the overheat protection mode, the engine temperature is too high, so it is necessary to reduce the air supply and oil supply to reduce the engine speed, thereby reducing the engine temperature. To this end, the pressure roller shaft 8 is locked by the locking mechanism 7 and the energy in the turbine 3 is recovered by the motor 6, so that the engine exhaust energy can be fully recovered as electrical energy, which can improve the engine thermal efficiency.

[0067] According to some embodiments of the present invention, the control method further comprises: receiving an engine start request signal and starting the engine; Obtain the engine's cooling water temperature, exhaust pipe 4 temperature, and lubricating oil temperature to determine whether the engine is in a cold state or a warm state; If the engine is in a cold state, the engine is controlled to enter the cold start phase until the engine runs normally; If the engine is in the warm-up state, determine whether the engine is in an overheated state. If so, control the engine to enter the overheating stage until the engine runs normally; if not, control the engine to enter the normal running stage.

[0068] Reference Figure 2 As shown, after receiving the engine start request signal, the engine is started. After the engine is started, firstly, according to the engine cooling water temperature, the engine exhaust pipe 4 temperature and the engine lubricating oil temperature, it is determined whether the engine is in a cold start state. If the engine is in a cold state, the cold start mode is entered until the engine state is in a warm state.

[0069] If the engine is in warm-up state, it is determined whether the engine is in overheating state based on the engine cooling water temperature, the engine exhaust pipe 4 temperature and the engine lubricating oil temperature. If the engine is in overheating state, it enters the overheating protection mode until the engine operating state is normal.

[0070] If the engine status is normal, a judgment is made based on the engine power demand and the intake and exhaust energy difference to determine whether to enter the speed regulation mode or the energy replenishment mode / feedback mode.

[0071] According to some embodiments of the present invention, the control method further includes: determining whether the engine needs to continue running according to the needs of the entire vehicle; if it needs to continue running, re-determining whether the engine is in an overheated state; if it needs to be shut down, executing a shutdown command by cutting off the engine injection signal, and recovering the mechanical energy in the turbine 3 through the motor 6.

[0072] A vehicle according to an embodiment of the third aspect of the present invention includes a control method for an electrically assisted turbocharger system.

[0073] The control method of the embodiment of the present invention is shown in Figure 2 As shown, the details are as follows: S1. After receiving the engine start request signal, start the engine and execute step S2.

[0074] S2. After the engine is started, first determine whether the engine is in a cold start state based on the engine cooling water temperature, the exhaust pipe 4 temperature and the lubricating oil temperature. If the engine is in a cold state, execute step S3; if the engine is in a warm state, execute step S4.

[0075] S3. After entering the cold start mode, the turbine shaft 9 is locked by the locking mechanism 7, and the compression wheel 1 is driven by the motor 6 to increase the pressure and replenish the air until the engine state is warm, and then step S4 is executed.

[0076] S4. Determine whether the engine is in an overheated state based on the engine cooling water temperature, the exhaust pipe 4 temperature and the lubricating oil temperature. If the engine is in an overheated state, execute step S5; if the engine state is normal, execute step S6.

[0077] S5. After entering the overheat protection mode, the pressure roller shaft 8 is locked by the locking mechanism 7 of the pressure roller 1, and the energy of the turbine 3 is recovered by the motor 6 until the engine state is normal, and then step S6 is executed.

[0078] S6. Determine whether the vehicle has a greater power demand for the engine through the accelerator pedal depth signal and the battery capacity signal. If the demand is greater, execute step S8; if the demand is less, execute step S7.

[0079] S7. Calculate the intake energy requirement and exhaust energy through the pressure sensors and temperature sensors in the intake pipe 2 and the exhaust pipe 4 combined with the rotation speed of the compressor wheel 1 and the turbine 3. If the energy difference is higher than the second threshold, execute step S8; if the energy difference is lower than the second threshold, execute step S9.

[0080] S9. After entering the speed regulation mode, the speed ratio is adjusted by the motor 6 to match the turbine 3 and the compressor 1 to the target economic speed. After the adjustment is completed, step S10 is executed.

[0081] S8. After entering the energy replenishment mode / feedback mode, the energy replenishment / feedback mode of the motor 6 is determined according to the intake energy demand and the exhaust energy. After the adjustment is completed, step S10 is executed.

[0082] S10. Determine whether the engine needs to continue running according to the vehicle demand. If it needs to continue running, execute step S4; if it needs to stop, execute step S11.

[0083] S11. The shutdown command is executed by cutting off the engine injection signal, and at the same time, the mechanical energy in the turbine 3 is recovered into the battery through the motor 6.

[0084] Therefore, the electrically assisted turbocharging system and control method of the present invention have the following effects: First, compared with the existing turbocharger and electric-assisted supercharger solutions, the rotational speeds of the turbine 3 and the compressor wheel 1 can be decoupled and independently controlled, which can effectively improve the hysteresis of the turbine 3.

[0085] Second, compared with the existing electric-assisted supercharger solution, the motor 6 can be arranged away from the turbine 3, which can effectively avoid the heat damage problem caused by the turbine 3.

[0086] Thirdly, compared with the existing combination of an electric supercharger and an electric turbine, the rotational speeds of the turbine 3 and the compressor wheel 1 can be coupled at a certain speed ratio to efficiently transmit mechanical energy and avoid losses during the conversion of mechanical energy into electrical energy.

[0087] Fourth, the rotation speed of the turbine 3 and the compressor wheel 1 is obtained through the rotation speed sensor, and the transmission ratio is adjusted in real time by the motor 6, so that the turbine 3 and the compressor wheel 1 always work in a high-efficiency condition, thereby improving the exhaust energy utilization rate.

[0088] Fifth, the intake and exhaust energy is calculated by the temperature / pressure sensors in the intake pipe 2 and the exhaust pipe 4, and the motor 6 is used to replenish energy / feedback in real time according to the energy difference, so that the supercharging system can meet the engine demand in time.

[0089] Sixth, when the engine is at high power and high speed, once the risk of engine overheating is detected, the pressure roller shaft 8 can be locked by the locking mechanism 7 and the energy of the turbine shaft 9 can be recovered by the motor 6, and the exhaust gas bypass valve can be eliminated to improve thermal efficiency.

[0090] Seventh, when it is detected that the engine is in a cold start state, the turbine shaft 9 can be locked by the locking mechanism 7 and the speed and pressure of the pressure wheel 1 can be quickly increased by the motor 6, thereby increasing the engine power and reducing emissions.

[0091] Eighth, the present invention comprehensively considers the power demand of the engine and the control logic of the difference between the intake energy and the exhaust energy. When the power demand is large and the difference between the intake and exhaust energy is large, it enters the energy replenishment / feedback mode to improve the transient response capability, and enters the speed regulation mode under other operating conditions to improve the system operating efficiency.

[0092] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0093] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0094] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An electrically assisted turbocharging system, characterized in that: include: A pressure wheel, the pressure wheel is arranged in the air intake pipe of the engine; a turbine, the turbine being arranged in an exhaust pipe of the engine; A differential mechanism, wherein the pressure wheel and the turbine are connected via the differential mechanism, and the differential mechanism and the pressure wheel are dynamically coupled or decoupled; and the differential mechanism and the turbine are dynamically coupled or decoupled; A motor is provided, wherein the motor is connected to the pressure wheel and the turbine through the differential mechanism, and the motor is configured such that the motor can adjust the transmission ratio through the differential mechanism or the motor can transmit power between the pressure wheel or the turbine through the differential mechanism.

2. The electrically assisted turbocharging system according to claim 1, characterized in that: Also includes: A locking mechanism is provided between the differential mechanism and the pressure wheel and between the differential mechanism and the turbine, and is used for selectively disconnecting the power coupling between the differential mechanism and the pressure wheel or the power coupling with the turbine.

3. The electrically assisted turbocharging system according to claim 1, characterized in that: The differential mechanism comprises: a sun gear, the turbine being connected to the sun gear via a turbine shaft; A planet carrier, wherein the pressure wheel is connected to the planet carrier via a pressure wheel shaft; A planetary gear ring, wherein the inner side of the planetary gear ring is meshed with the planetary gear on the planetary carrier, the outer side of the planetary gear ring is meshed with the gear of the motor, and the output end of the motor is transmission connected with the gear.

4. A control method for an electrically assisted turbocharger system, characterized in that: For controlling the electrically assisted turbocharger system according to any one of claims 1 to 3, the control method comprises: When the engine is in the normal operation stage, the motor is started, the differential mechanism is power-coupled with the pressure wheel and the turbine, and the motor adjusts the transmission ratio through the differential mechanism; or drives the pressure wheel to increase pressure or recover mechanical energy in the turbine through the differential mechanism.

5. The control method of the electrically assisted turbocharger system according to claim 4, characterized in that: The control method further comprises: Get the power requirement of the engine; If the power demand of the engine is higher than a threshold value, the electric motor drives the compressor to increase pressure or recover mechanical energy in the turbine through the differential mechanism; If the power demand of the engine is below a certain threshold, the electric machine adjusts the transmission ratio via the differential mechanism.

6. The control method of the electrically assisted turbocharger system according to claim 5, characterized in that: If the power demand of the engine is lower than a threshold value, the method further comprises: Obtaining the difference between exhaust energy and intake energy; If the power demand of the engine is lower than a first threshold and the difference between the exhaust energy and the intake energy is higher than a second threshold, the electric motor drives the compressor to boost pressure or recover mechanical energy in the turbine through the differential mechanism; If the power demand of the engine is lower than a first threshold and the difference between the exhaust energy and the intake energy is lower than a second threshold, the electric machine adjusts the transmission ratio via the differential mechanism.

7. The control method of the electrically assisted turbocharger system according to claim 6, characterized in that: If the power demand of the engine is lower than a first threshold and the difference between the exhaust energy and the intake energy is lower than a second threshold, the motor adjusts the transmission ratio through the differential mechanism, further comprising: Acquiring an intake flow rate and an intake pressure of the intake pipe and an exhaust flow rate and an exhaust pressure of the exhaust pipe; Determining target economic speeds of the compressor and the turbine based on the intake flow rate, the exhaust flow rate, the intake pressure, and the exhaust pressure; Based on the target economic speeds of the impeller and the turbine, the motor is controlled to adjust the transmission ratio of the differential mechanism to match the impeller and the turbine to the target economic speeds.

8. The control method of the electrically assisted turbocharger system according to claim 6, characterized in that: The step of obtaining the difference between the exhaust energy and the intake energy includes: The pressure and temperature of the intake pipe and the exhaust pipe and the rotation speed of the compressor wheel and the turbine are obtained to determine the intake energy and the exhaust energy, and to calculate the difference between the intake energy and the exhaust energy.

9. The control method of the electrically assisted turbocharger system according to claim 5, characterized in that: The obtaining of the power requirement of the engine comprises: Obtaining a depth signal of an accelerator pedal of the vehicle to determine a total power demand; Obtain battery capacity signal to determine battery power requirements, Based on the total power demand and the power demand of the battery, the power demand of the engine is determined.

10. The control method of the electrically assisted turbocharger system according to claim 5, characterized in that: If the power demand of the engine is higher than a threshold value, the motor drives the pressure wheel to increase pressure or recover mechanical energy in the turbine through the differential mechanism, further comprising: Obtain intake energy and exhaust energy; If the exhaust energy is greater than the intake energy, the motor recovers the mechanical energy in the turbine through the differential mechanism; If the exhaust energy is lower than the intake energy, the motor drives the compression wheel to increase pressure through the differential mechanism.

11. The control method of the electrically assisted turbocharger system according to claim 4, characterized in that: The control method further comprises: When the engine is in a cold start stage, the motor is started, the differential mechanism is dynamically decoupled from the turbine and dynamically coupled to the pressure wheel, and the motor drives the pressure wheel to increase pressure through the differential mechanism; When the engine is in an overheating stage, the motor is started, the differential mechanism is dynamically decoupled from the pressure wheel and dynamically coupled to the turbine, and the motor recovers the mechanical energy of the turbine through the differential mechanism.

12. The control method of the electrically assisted turbocharger system according to claim 11, characterized in that: The control method further comprises: receiving an engine start request signal and starting the engine; Obtain the engine's cooling water temperature, exhaust pipe temperature, and lubricating oil temperature to determine whether the engine is in a cold state or a warm state; if the engine is in a cold state, control the engine to enter a cold start phase until the engine runs normally; If the engine is in the warm-up state, determine whether the engine is in an overheated state. If so, control the engine to enter the overheating stage until the engine runs normally; if not, control the engine to enter the normal running stage.

13. The control method of the electrically assisted turbocharger system according to claim 12, characterized in that: The control method further comprises: Whether the engine needs to continue running is determined based on the needs of the entire vehicle. If it needs to continue running, whether the engine is in an overheating state is re-determined. If it needs to be shut down, the shutdown command is executed by cutting off the engine injection signal, and the mechanical energy in the turbine is recovered by the motor.

14. A vehicle comprising the electrically assisted turbocharging system according to any one of claims 1 to 3.

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