A method for controlling an electronic supercharger and a turbocharger in parallel

Abstract

A control method for parallel connection of an electronic supercharger and a turbocharger, which is used for parallel connection of an electronic supercharger and a turbocharger, and the parallel connection comprises: an automobile engine, which is provided with an air inlet pipe and an air outlet pipe, the air inlet pipe is connected to a first air inlet branch pipe and a second air inlet branch pipe arranged in parallel; a turbocharger, which is provided with a turbine assembly and a compressor assembly, the turbine assembly is arranged on the air outlet pipe, and the compressor assembly is arranged on the first air inlet branch pipe; and an electronic supercharger, which is provided with a second compressor assembly, the second compressor assembly is arranged on the second air inlet branch pipe, and a third control valve is arranged on the second air inlet branch pipe. The application is suitable for a double supercharger system with parallel connection structure, avoids temperature rise caused by secondary supercharging in series connection structure, improves the service life of the equipment, and can select different optimized supercharging schemes by setting a target air intake amount to ensure stable operation according to different engine working conditions.

Description

Technical Field

[0001] This invention belongs to the field of turbocharger technology, specifically relating to a control method for a parallel scheme of an electronic supercharger and a turbocharger. Background Technology

[0002] A turbocharger in a car improves combustion efficiency and generates more power by supplying more air to the engine. The turbocharger housing is an important structure on the turbocharger. The turbocharger housing uses exhaust gases from the engine to drive the compressor on the turbocharger as the turbine impeller rotates at high speed, increasing the intake air volume and thus increasing the engine's output power.

[0003] Currently, with technological advancements, electric superchargers have emerged. These superchargers use an electric motor to drive their compressor, increasing the engine's intake air volume. Furthermore, to further increase the engine's intake air volume and meet the demands of high-power operation, there are solutions that connect the electric supercharger and turbocharger in series. This series connection results in the gas undergoing two compressions, leading to higher temperatures and potentially causing significant compressor deformation and casing rubbing, while also increasing the risk of low-cycle fatigue. In addition, traditional twin-charger systems have a limited and inflexible operating mode, requiring improvement.

[0004] Therefore, based on the above situation, this application further studies this dual-charger system and its control. Summary of the Invention

[0005] To address the shortcomings of the existing technology, this invention provides a control method for a parallel connection of an electronic supercharger and a turbocharger, applicable to a parallel dual-supercharger system. This method avoids the temperature rise caused by secondary supercharging in a series structure, thus improving equipment lifespan. Furthermore, it can automatically select an optimized supercharging scheme for different engine operating conditions, ensuring stable system operation.

[0006] The present invention is solved by the following technical solution.

[0007] A control method for a parallel configuration of an electric supercharger and a turbocharger is disclosed. The parallel configuration includes: an automotive engine with an intake manifold and an exhaust manifold, the intake manifold being connected to a first intake branch pipe and a second intake branch pipe arranged in parallel; a throttle valve on the intake manifold; a turbocharger with a turbine assembly and a compressor assembly, the turbine assembly being located on the exhaust manifold, and the compressor assembly being located on the first intake branch pipe, with external recirculation pipes at both ends of the first intake branch pipe; a first control valve on the first intake branch pipe, and a second control valve on the external recirculation pipe; a bypass valve on the turbine assembly; and an electric supercharger with a second compressor assembly. The engine assembly includes a second compressor assembly mounted on a second intake manifold, and a third control valve mounted on the second intake manifold. The control method includes at least one of the following steps: S10: The second control valve is open, the first control valve is closed, and the third control valve is open. At this time, the electric supercharger drives the second compressor assembly to work; the turbine assembly of the turbocharger works, and the compressor assembly compresses air for self-circulation; S20: The second control valve is closed, the first control valve is open, and the third control valve is closed. At this time, the electric supercharger does not work, and only the turbocharger provides the intake air volume required for engine combustion; S30: The second control valve is closed, the first control valve is open, and the third control valve is open. The electric supercharger and the turbocharger work simultaneously to provide sufficient intake air volume for the engine.

[0008] In traditional twin-charger structures, the compressors of the electric supercharger and turbocharger are connected in series. After the first pressurization, the airflow temperature rises, and the compressor temperature during the second pressurization process easily exceeds 200°C, resulting in poor operational stability, severely impacting product lifespan, and increasing the risk of failure. This application employs a parallel design, overcoming industry norms and effectively solving this problem. Using the parallel structure of this application, at low power operation, only the turbocharger or only the electric supercharger can operate to meet pressurization requirements; at high power operation, both the electric supercharger and turbocharger operate, satisfying the intake air volume requirements. Furthermore, the compressors of the turbocharger and electric supercharger are arranged parallel on a parallel intake manifold, allowing for intake air intake in a single pressurization cycle, avoiding excessive compressor temperature and preventing failure risks, thus increasing system stability and lifespan. In addition, this application utilizes multiple control valves to achieve different pressurization and intake schemes, making it highly practical.

[0009] In a preferred embodiment, the method further includes the following step: S40: A first intercooler and a second intercooler cool the compressed hot air; the first intercooler is located on the pipeline between the first control valve and the turbocharger, and the second intercooler is located on the pipeline between the third control valve and the electric supercharger. The intercoolers are used to cool the gas to reduce the engine's thermal load, increase the intake air volume, and thus increase the engine's power.

[0010] In a preferred embodiment, the method further includes the following steps: S50: The functional block determines the turbine inlet pressure P3 and turbine inlet flow m3 of the turbine assembly by controlling the opening or closing angle of the bypass valve or VNT; P3 and m3 correspond to the corresponding turbine speeds and are used to monitor the turbocharger speed nsens. The turbocharger speed nsens and the compressor inlet pressure P11 together determine the output pressure P20 of the compressor assembly; the intake airflow at pressure P20 is reduced to pressure P21 after passing through the first intercooler and the first control valve; S60: The second compressor assembly determines the outlet pressure P20' of the second compressor assembly by the compressor inlet pressure P11 and the motor speed nsens-e of the electric supercharger. The intake airflow at outlet pressure P20' is reduced to pressure P21' after passing through the second intercooler and the third control valve; S70: P21 and P21' are combined to determine the engine intake pressure P22. A throttle valve is provided on the intake pipe to regulate the intake volume.

[0011] In a preferred embodiment, the method further includes the following steps: S80: The turbine assembly contains a turbine characteristic curve family 3ctr, the compressor assembly contains a compressor characteristic curve family 7ctr, and the second compressor assembly contains a corresponding compressor characteristic curve family 10ctr. The target pressure Pdes is determined in the characteristic curve family according to the magnitude of the target load. The opening and / or opening degree of the first control valve, the second control valve, and the third control valve are determined by comparing the observed engine intake pressure P22 with the target Pdes; S90: The function block receives the target command released by the ECU.

[0012] In a preferred embodiment, step S10 includes the following specific steps: S11: Under low-speed conditions, the engine displacement is small, the turbocharger intake pressure is insufficient, and the compressor is prone to surge; at this time, the function block controls the second control valve to open, the first control valve to close, and the third control valve to open. At this time, the engine intake air volume is provided by the second compressor assembly of the electric supercharger, the turbine assembly of the turbocharger works, and the compressed air of the compressor assembly is self-circulated through the opened second control valve; according to the target load, the target pressure Pdes is determined, and the function block determines the electric supercharger motor speed nsens-e according to the compressor characteristic curve family 10ctr; the motor speed nsens-e and the compressor intake pressure P11 together determine the engine input pressure P22; P22 is compared with the target intake pressure Pdes, and then the function block adjusts the electric supercharger motor speed nsens-e, and so on until P22 meets the target intake pressure Pdes.

[0013] In a preferred embodiment, step S20 includes the following specific steps: S21: As the target load increases, when the intake air volume delivered by the electronic supercharger reaches the set value, i.e., when P3 and nsens are detected to have reached the set value, the pressure in the compressor characteristic curve family 7ctr at that speed nsens and the outlet pressure P20' are compared; if P20' is contained by the pressure in the compressor characteristic curve family 7ctr and avoids surge and blockage lines, the turbocharger replaces the electronic supercharger, i.e., the function block controls the second control valve to close, the first control valve to open, and the third control valve to close; at this time, only the turbocharger 1 needs to participate in the work to meet the target pressure Pdes requirement, and P20 replaces P20'. This process starts from the compressor assembly in a low-speed, low-pressure state, that is, when the turbocharger can provide a stable intake air volume well under high load and high speed conditions, the turbocharger replaces the electronic supercharger.

[0014] In a preferred embodiment, step S20 includes the following specific steps: S22: The turbocharger speed increases. At this time, the turbocharger still operates alone. When the function block detects that the engine intake air volume P22 is greater than the target pressure Pdes, it finds the target speed corresponding to the target pressure Pdes according to the compressor characteristic curve family 7ctr. Based on the determined target speed, it determines the turbine component corresponding to the turbine characteristic curve family 3ctr, the turbine component corresponding to the pressure P3 and flow rate m3. Then, the function block drives the bypass valve to open to a determined angle to release a portion of the excess engine exhaust gas flow. It continues to monitor the relationship between the engine intake air volume P22 and the target pressure Pdes and dynamically adjusts the bypass valve opening angle. Similarly, when the function block detects that the engine intake air volume P22 is less than the target pressure Pdes, the function block drives the bypass valve to reduce the opening angle.

[0015] In a preferred embodiment, step S30 includes the following specific steps: S31: When the engine is at high speed and high load, it is detected that the bypass valve is in the closed state. When the engine intake air volume P22 of the turbocharger working alone is less than the target pressure Pdes, the function block controls the second control valve to close, the first control valve to open, and the third control valve to open. According to the monitored P22 and the corresponding flow information, the difference between the target flow and the target flow can be determined. At this time, the electronic supercharger makes up for this target flow difference. The target speed nsens-e of the second compressor component corresponding to the pressure ratio and flow state can be obtained from the compressor characteristic curve family 10ctr. The motor of the electronic supercharger driven by the function block provides the insufficient flow portion of the turbocharger to the target pressure Pdes and its corresponding target flow at the nsens-e speed.

[0016] Compared with the prior art, the present invention has the following advantages: it provides a control method for a parallel scheme of electric supercharger and turbocharger, which is applicable to the dual supercharger system with parallel structure, avoids the temperature rise caused by secondary supercharging in series structure, and improves the service life of equipment; it can automatically select the optimized supercharging scheme for different engine operating conditions to ensure stable operation of the system. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a dual-charger in the prior art.

[0018] Figure 2 This is a schematic diagram of the parallel structure of the dual turbocharger in this application.

[0019] Figure 3 This is a schematic diagram of the function block control turbocharger in this application.

[0020] Figure 4 This is a flowchart illustrating the parameter calling and control process in this application.

[0021] Figure 5 This is a diagram of the turbine characteristic curve family 3ctr in this application.

[0022] Figure 6 This is a graph of the compressor characteristic curve family 7ctr in this application.

[0023] Figure 7 This is a graph of the compressor characteristic curve family 10ctr in this application. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0025] In the following embodiments, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0026] In the description of this invention, it should be understood that terms such as center, longitudinal, transverse, length, width, thickness, upper, lower, front, rear, left, right, vertical, horizontal, top, bottom, inner, outer, clockwise, counterclockwise, etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing and simplifying the description of this invention; therefore, they should not be construed as limiting this invention. Furthermore, terms such as first, second, etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features shown. In the description of this invention, unless otherwise expressly specified and limited, terms such as installation, connection, linking, etc., should be interpreted broadly, and those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0027] Figure 1 The diagram shows a schematic of a twin-charger in the prior art. As can be seen from the diagram, the car engine 5 is equipped with an intake pipe 52 and an exhaust pipe 51. The turbine assembly 11 of the turbocharger 1 is located on the exhaust pipe 51, and the compressor assembly 12 of the turbocharger 1 is located on the intake pipe 52. Furthermore, the second compressor assembly 41 of the electric supercharger 4 is also located on the intake pipe 52. In this structure, the turbocharger 1 and the electric supercharger 4 are connected in series, which means that neither the turbocharger 1 nor the electric supercharger 4 can work independently. As long as one compressor assembly is working, the airflow will inevitably drive the other compressor assembly to rotate, which is very troublesome. Moreover, due to the airflow in the exhaust pipe 51, the shaft system in the turbocharger 1 is basically rotating continuously, and its compressor assembly 12 is always working. At this time, even if the second compressor assembly 41 is not turned on, it will be passively rotated. In addition, the intake air temperature after two boosts is high, which is harmful and has a high risk of accidents, resulting in poor system stability.

[0028] like Figure 2As shown, this application relates to a parallel structure of an electronic supercharger and a turbocharger, including an automobile engine 5. The automobile engine 5 is provided with an intake pipe 52 and an exhaust pipe 51. The intake pipe 52 is connected to a first intake branch pipe 521 and a second intake branch pipe 522 arranged in parallel. It includes a turbocharger 1. The turbine assembly 11 of the turbocharger 1 is provided on the exhaust pipe 51. The compressor assembly 12 of the turbocharger 1 is provided on the first intake branch pipe 521, and the first intake branch pipe 521 at both ends of the compressor assembly 12 is provided with an external circulation pipe 523. The first intake branch pipe 521 is provided with a first control valve 3, and the external circulation pipe 523 is provided with a second control valve 2. It also includes an electronic supercharger 4. The second compressor assembly 41 of the electronic supercharger 4 is provided on the second intake branch pipe 522, and the second intake branch pipe 522 is provided with a third control valve 44. In addition, a bypass valve 14 is provided on the turbine assembly 11, and a throttle valve 525 is provided on the intake pipe 52 for regulating the intake volume.

[0029] Specifically, in this application, a first intercooler 21 is provided on the pipeline between the first control valve 3 on the first intake manifold 521 and the turbocharger 1, and a second intercooler 22 is provided on the pipeline between the third control valve 44 on the second intake manifold 522 and the electric supercharger 4, for cooling the gas to reduce the engine's thermal load, increase the intake volume, and thus increase the engine's power.

[0030] This application adopts a parallel design, which overcomes the industry's conventional thinking and solves this problem well. Furthermore, the parallel scheme in this application can have a variety of different working states, as detailed below.

[0031] S10: Low-speed stage: The second control valve 2 is open, the first control valve 3 is closed, and the third control valve 44 is open. At this time, the electric supercharger 4 drives the second compressor assembly 41 to work; the turbine assembly 11 of the turbocharger 1 works, and the compressed air in the compressor assembly 12 is self-circulated (through the external circulation pipe 523) and does not participate in the intake work of the engine 5. In this way, the intake volume of the engine can be precisely controlled by the electric supercharger 4, avoiding the situation of insufficient intake volume of the turbocharger 1 at low speeds.

[0032] S20: Medium load stage: Second control valve 2 is closed, first control valve 3 is open, and third control valve 44 is closed. At this time, the electric supercharger 4 is not working, and only the turbocharger 1 provides the intake air volume required for engine combustion.

[0033] S30: High-speed, high-load stage: More and greater intake air pressure is required. At this time, the second control valve 2 is closed, the first control valve 3 is open, the third control valve 44 is open, the electric supercharger 4 and the turbocharger 1 work at the same time, and the first intercooler 21 and the second intercooler 22 cool the compressed hot air in order to provide sufficient intake air for the engine.

[0034] S40: The first intercooler 21 and the second intercooler 22 cool the compressed hot air; the first intercooler 21 is located on the pipeline between the first control valve 3 and the turbocharger 1, and the second intercooler 22 is located on the pipeline between the third control valve 44 and the electric supercharger 4. The intercoolers are used to cool the gas to reduce the engine's thermal load, increase the intake air volume, and thus increase the engine's power.

[0035] S50: The function block determines the turbine inlet pressure P3 and turbine inlet flow m3 of the turbine assembly 11 by controlling the opening or closing angle of the bypass valve 14 or VNT; P3 and m3 correspond to the corresponding turbine speeds and are used to monitor the turbocharger speed nsens. The turbocharger speed nsens and the compressor inlet pressure P11 together determine the output pressure P20 of the compressor assembly 12; the inlet air at pressure P20 is reduced to pressure P21 after passing through the first intercooler 21 and the first control valve 3.

[0036] S60: The second compressor assembly 41 determines the outlet pressure P20´ of the second compressor assembly 41 by the compressor inlet pressure P11 and the motor speed nsens-e of the electronic supercharger 4. The outlet pressure P20´ of the inlet air is reduced to P21´ after passing through the second intercooler 22 and the third control valve 44.

[0037] S70: P21 and P21' converge to determine the engine intake pressure P22. The intake manifold 52 is equipped with a throttle valve 525 for regulating the intake volume.

[0038] S80: Turbine assembly 11 contains a family of turbine characteristic curves 3ctr, compressor assembly 12 contains a family of compressor characteristic curves 7ctr, and second compressor assembly 41 contains a corresponding family of compressor characteristic curves 10ctr. The target pressure Pdes is determined based on the magnitude of the target load in the characteristic curve family. The opening and / or opening degree of the first control valve 3, the second control valve 2, and the third control valve 44 are determined by comparing the observed engine intake pressure P22 with the target Pdes.

[0039] S90: Function block receives the target command released by ECU. The function block can be a processing chip, such as an automotive processing chip or a PLC chip.

[0040] The steps in S10-S30 of this application are described in further detail below.

[0041] Step S10 includes the following specific steps: S11: Under low-speed conditions, the engine displacement is small, the turbocharger intake pressure is insufficient, and the compressor is prone to surge; at this time, the function block controls the second control valve 2 to open, the first control valve 3 to close, and the third control valve 44 to open. At this time, the engine intake air volume is provided by the second compressor assembly 41 of the electric supercharger 4, the turbine assembly 11 of the turbocharger 1 works, and the compressor assembly 12 compresses the air through the opened second control valve 2 for self-circulation; according to the target load, the target pressure Pdes is determined, and the function block determines the electric supercharger 4 motor speed nsens-e according to the compressor characteristic curve family 10ctr; the motor speed nsens-e and the compressor intake pressure P11 together determine the engine input pressure P22; P22 is compared with the target intake pressure Pdes, and then the function block adjusts the electric supercharger 4 motor speed nsens-e, and so on until P22 meets the target intake pressure Pdes.

[0042] Step S20 includes the following specific steps: S21: As the target load increases, when the intake air volume delivered by the electronic supercharger 4 reaches the set value, i.e., when P3 and nsens are detected to have reached the set value, the pressure and outlet pressure P20' in the compressor characteristic curve family 7ctr at that speed nsens are compared; if P20' is contained by the pressure in the compressor characteristic curve family 7ctr and avoids surge and blockage lines, the turbocharger replaces the electronic supercharger, i.e., the function block controls the second control valve 2 to close, the first control valve 3 to open, and the third control valve 44 to close; at this time, only the turbocharger 1 needs to participate in the work to meet the target pressure Pdes requirement, and P20 replaces P20'. This process starts from the compressor assembly 12 in a low-speed, low-pressure state, that is, when the turbocharger can provide a stable intake air volume well under high load and high speed conditions, the turbocharger replaces the electronic supercharger.

[0043] Step S20 includes the following specific steps: S22: The speed of turbocharger 1 increases. At this time, turbocharger 1 still works alone. When the function block detects that the engine intake air volume P22 is greater than the target pressure Pdes, it finds the target speed corresponding to the target pressure Pdes by corresponding to the compressor characteristic curve family 7ctr. Based on the determined target speed, it determines the pressure P3 and flow rate m3 corresponding to the turbine component 11 by corresponding to the turbine characteristic curve family 3ctr. Then, the function block drives the bypass valve 14 to open to a determined angle to release a portion of the excess engine exhaust gas flow. It continues to monitor the relationship between the engine intake air volume P22 and the target pressure Pdes and dynamically adjusts the opening angle of the bypass valve 14. Similarly, when the function block detects that the engine intake air volume P22 is less than the target pressure Pdes, it drives the bypass valve 14 to reduce the opening angle.

[0044] Step S30 includes the following specific steps: S31: When the engine is at high speed and high load, it is detected that the bypass valve 14 is in the closed state. When the engine intake air volume P22 of the turbocharger 1 working alone is less than the target pressure Pdes, the function block controls the second control valve 2 to close, the first control valve 3 to open, and the third control valve 44 to open. According to the monitored P22 and the corresponding flow information, the difference with the target flow can be determined. At this time, the electronic supercharger 4 makes up for this target flow difference. The target speed nsens-e of the second compressor component 41 corresponding to the pressure ratio and flow state can be obtained from the compressor characteristic curve family 10ctr. The motor of the electronic supercharger driven by the function block provides the insufficient flow part of the turbocharger to the target pressure Pdes and its corresponding target flow at the nsens-e speed.

[0045] In one specific embodiment, the target intake flow rate mdes1 > m1: (e.g.) Figure 5 As shown, an exhaust flow rate m3 = 0.9 corresponds to a speed of 80,000 RPM. At 80,000 RPM, the pressure ratio of the reduced pressure corresponds to a flow rate m1. If the flow rate m3 = 0.9 corresponds to a target intake flow rate mdes1 > m1, then the electronic supercharger will intervene to provide sufficient intake flow. This situation is more common in high-altitude conditions.

[0046] As can be seen from the above description, this application provides a control method for a parallel connection of an electronic supercharger and a turbocharger, applicable to a parallel twin-charger system. This avoids the temperature rise caused by secondary supercharging in a series structure, thus improving equipment lifespan. Furthermore, this application allows for the selection of different optimized supercharging schemes by setting a target intake volume for different engine operating conditions, ensuring stable system operation.

[0047] The scope of protection of this invention includes, but is not limited to, the above embodiments. The scope of protection of this invention is defined by the claims. Any substitutions, modifications, or improvements to this technology that are easily conceived by those skilled in the art fall within the scope of protection of this invention.

Claims

1. A control method for a parallel operation of an electric supercharger and a turbocharger, characterized in that, This control method is used for a parallel configuration of an electric supercharger and a turbocharger, which includes: The automobile engine (5) is provided with an intake pipe (52) and an exhaust pipe (51). The intake pipe (52) is connected to a first intake branch pipe (521) and a second intake branch pipe (522) arranged in parallel. The intake pipe (52) is provided with a throttle valve (525). A turbocharger (1) is provided with a turbine assembly (11) and a compressor assembly (12). The turbine assembly (11) is located on the outlet pipe (51), and the compressor assembly (12) is located on the first intake branch pipe (521). An external circulation pipe (523) is provided on the first intake branch pipe (521) at both ends of the compressor assembly (12). A first control valve (3) is provided on the first intake branch pipe (521), and a second control valve (2) is provided on the external circulation pipe (523). A bypass valve (14) is provided on the turbine assembly (11). An electronic supercharger (4) is provided with a second compressor assembly (41), which is located on a second intake manifold (522), and a third control valve (44) is provided on the second intake manifold (522). The control method includes the following steps: S10: The second control valve (2) is open, the first control valve (3) is closed, and the third control valve (44) is open. At this time, the electronic supercharger (4) drives the second compressor assembly (41) to work; the turbine assembly (11) of the turbocharger (1) works, and the compressor assembly (12) compresses air for self-circulation. S20: The second control valve (2) is closed, the first control valve (3) is open, and the third control valve (44) is closed. At this time, the electric supercharger (4) does not work, and the turbocharger (1) alone provides the intake air required for engine combustion. S30: The second control valve (2) is closed, the first control valve (3) is open, the third control valve (44) is open, and the electric supercharger (4) and the turbocharger (1) work simultaneously to provide sufficient intake air for the engine; S40: The first intercooler (21) and the second intercooler (22) cool the compressed hot air; the first intercooler (21) is located on the pipeline between the first control valve (3) and the turbocharger (1), and the second intercooler (22) is located on the pipeline between the third control valve (44) and the electric supercharger (4); S50: The function block determines the turbine inlet pressure P3 and turbine inlet flow m3 of the turbine assembly (11) by controlling the opening or closing angle of the bypass valve (14) or the variable nozzle turbocharger (VNT); P3 and m3 correspond to the corresponding turbine speeds and are used to monitor the turbocharger speed nsens. The turbocharger speed nsens and the compressor inlet pressure P11 together determine the output pressure P20 of the compressor assembly (12); the inlet air of pressure P20 is reduced to P21 after passing through the first intercooler (21) and the first control valve (3); S60: The second compressor assembly (41) determines the outlet pressure P20' of the second compressor assembly (41) by the compressor inlet pressure P11 and the motor speed nsens-e of the electronic booster (4). The outlet pressure P20' of the inlet air flows through the second intercooler (22) and the third control valve (44) and the pressure drops to P21'. S70: P21 and P21' converge to determine the engine intake pressure P22, and the intake pipe (52) is equipped with a throttle valve (525). S80: Turbine assembly (11) contains a family of turbine characteristic curves 3ctr, compressor assembly (12) contains a family of compressor characteristic curves 7ctr, and second compressor assembly (41) contains a family of corresponding compressor characteristic curves 10ctr. The target pressure Pdes is determined according to the size of the target load in the characteristic curve family. The opening and / or opening degree of the first control valve (3), the second control valve (2), and the third control valve (44) are determined by comparing the observed engine intake pressure P22 with the target pressure Pdes. S90: Function block receives the target command released by the ECU; Step S20 includes the following specific steps: S21: As the target load increases, when the intake air volume delivered by the electronic supercharger (4) reaches the set value, that is, when P3 and nsens are detected to reach the set value, compare the pressure in the compressor characteristic curve family 7ctr and the outlet pressure P20´ at the nsens speed; if P20´ is contained by the pressure in the compressor characteristic curve family 7ctr and avoids the surge and blockage lines, the turbocharger replaces the electronic supercharger to work, that is, the function block controls the second control valve (2) to close, the first control valve (3) to open, and the third control valve (44) to close; at this time, only the turbocharger (1) needs to participate in the work to meet the target pressure Pdes requirement, and P20 replaces P20´; Step S30 includes the following specific steps: S31: When the engine is at high speed and high load, the bypass valve (14) is detected to be closed. When the engine intake pressure P22 of the turbocharger (1) is less than the target pressure Pdes, the function block controls the second control valve (2) to close, the first control valve (3) to open, and the third control valve (44) to open. The difference between the monitored P22 and the target flow can be determined based on the monitored P22 and the corresponding flow information. At this time, the electronic supercharger (4) will make up for this flow difference. The motor speed nsens-e of the second compressor component (41) corresponding to the pressure ratio and flow state can be obtained from the compressor characteristic curve family 10ctr. The motor of the electronic supercharger driven by the function block provides the insufficient flow part of the turbocharger for the target pressure Pdes and its corresponding target flow at the nsens-e speed.

2. The control method for a parallel connection of an electric supercharger and a turbocharger according to claim 1, characterized in that, Step S10 includes the following specific steps: S11: In low-speed operation, the engine displacement is small, the turbocharger intake pressure is insufficient, and the compressor is prone to surge. At this time, the second control valve (2) is opened by the function block control, the first control valve (3) is closed, and the third control valve (44) is opened. At this time, the engine intake volume is provided by the second compressor assembly (41) of the electronic supercharger (4), the turbine assembly (11) of the turbocharger (1) works, and the compressor assembly (12) compresses the air and performs self-circulation through the opened second control valve (2). Based on the magnitude of the target load, the target pressure Pdes is determined. The function block determines the motor speed nsens-e of the electronic supercharger (4) based on the compressor characteristic curve family 10ctr. The motor speed nsens-e and the compressor intake pressure P11 together determine the engine intake pressure P22. P22 is compared with the target pressure Pdes, and then the function block adjusts the motor speed nsens-e of the electronic supercharger (4). This cycle continues until P22 meets the target pressure Pdes.

3. A control method for a parallel operation of an electric supercharger and a turbocharger according to claim 1 or 2, characterized in that, Step S20 includes the following specific steps: S22: The speed of the turbocharger (1) increases. At this time, the turbocharger (1) still works alone. When the function block detects that the engine intake pressure P22 is greater than the target pressure Pdes, the corresponding compressor characteristic curve family 7ctr finds the target speed corresponding to the target pressure Pdes. Based on the determined target speed, the corresponding turbine characteristic curve family 3ctr determines the pressure P3 and flow m3 of the turbine assembly (11). Then, the function block drives the bypass valve (14) to open to a determined angle to release a portion of the excess engine exhaust flow. Continue to monitor the relationship between the engine intake pressure P22 and the target pressure Pdes, and dynamically adjust the opening angle of the bypass valve (14). Similarly, when the function block detects that the engine intake pressure P22 is less than the target pressure Pdes, the function block drives the bypass valve (14) to reduce the opening angle.

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