Control method of tandem type hybrid power aircraft

Abstract

The invention relates to the technical field of aircrafts, in particular to a control method of a tandem type hybrid power aircraft, which comprises a starting system, a power generation system, a monitoring system, an electric drive system, an integrated microcontroller, a PC (Personal Computer) upper computer and a power management control module, and is characterized in that the PC upper computer is connected with the integrated microcontroller through a network cable; the integrated microcontroller is connected with the power management control module; the control method of the tandem hybrid aircraft comprises the step of controlling the hybrid aircraft to be switched among a power generation system battery dual-output operation mode, a power generation system output battery input operation mode, a pure battery output operation mode and a pure power generation system output operation mode according to P power generation, P power and P fan. Therefore, the energy demand distribution condition of the tandem hybrid aircraft under different working modes and working conditions is improved, the operation efficiency of each core component of the system is improved, the robustness of a control strategy is guaranteed, and energy consumption is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft, and in particular to a control method for a series hybrid power aircraft. Background Art

[0002] In recent years, the aviation industry has been an important part of the transportation system, and its carbon emissions account for a considerable proportion. The overall efficiency of the power system of traditional fuel aircraft is low, the noise pollution is large, and the energy types are widely distributed, which is not conducive to management. The aircraft with electric propulsion system has higher efficiency, better reliability, and lower noise. It has obvious advantages in maintainability and fuel economy, but due to the limitations of battery technology, the development of pure electric aircraft is limited. Hybrid aircraft can take into account the advantages of both. Considering the simplicity of the control strategy, the series hybrid aircraft adopts the series type. Small and medium-power aircraft are flexible and versatile, and the manufacturing cost is much lower than that of heavy aircraft. They have broad application prospects in many industries and fields such as medical rescue, sports and entertainment, disaster relief, and urban security maintenance. Combined with the rapid development of hybrid aircraft, the overall control strategy of 16kW series hybrid aircraft is considered.

[0003] At present, the existing control methods for small and medium-power series hybrid aircraft have poor effects on allocating the energy requirements of the whole machine under different working modes and conditions. The control strategy is relatively dependent on the parameters of the motor itself. The motor parameters are prone to change under complex working conditions at high altitudes, which greatly reduces the control effect. It is impossible to achieve the optimal distribution of the power of the whole system and cannot ensure the efficient operation of all parts of the system.

[0004] It should be noted that the information disclosed in this background technology section is only intended to increase the understanding of the overall background of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes prior art already known to a person skilled in the art. Summary of the invention

[0005] The purpose of the embodiments of the present invention is to provide a control method for a series hybrid power aircraft, aiming to solve the problems existing in the above-mentioned background technology.

[0006] The present invention provides a control method for a series hybrid aircraft, wherein the series hybrid aircraft includes a starting system, a power generation system, a monitoring system, an electric drive system, an integrated microcontroller, a PC host computer and a power management control module. The starting system includes a battery, an inverter, an integrated starter motor and a piston engine, wherein the battery is connected to the inverter, the inverter is connected to the integrated microcontroller, the integrated starter motor is connected to the integrated microcontroller, and the piston engine is mechanically connected to the integrated starter motor. The power generation system and the starting system share the integrated starter motor and the piston engine, wherein the power generation system includes a rectifier bridge, and the rectifier bridge is connected to the integrated microcontroller. The monitoring system includes a K-type thermocouple, a Hall speed sensor and a piston engine electronic control unit, wherein the K-type thermocouple and the Hall speed sensor are connected to the piston engine, and the piston engine electronic control unit is connected to the integrated microcontroller. The electric drive system includes a ducted fan and a drive motor, wherein the drive motor is connected to the inverter, and the ducted fan is connected to the drive motor, and the drive motor provides driving force for the ducted fan. The PC host computer is connected to the integrated microcontroller via a network cable, and the integrated microcontroller is connected to the power management control module. The power generation power of the power generation system is defined as Pfa, the storage power of the battery is defined as Pdi, and the output power of the ducted fan is defined as Pfan. The control method of the series hybrid aircraft includes the following steps: according to Pfa, Pdi and Pfan, the hybrid aircraft is controlled to switch between the power generation system battery dual output operation mode, the power generation system output battery input operation mode, the pure battery output operation mode and the pure power generation system output operation mode.

[0007] Further, when the maximum output power of the power generation system is less than the output power of the ducted fan, and the storage power of the battery is higher than the set value of the safe storage power of the battery, the hybrid aircraft is in the power generation system battery dual output operation mode; When the output power of the power generation system is greater than the output power of the ducted fan, and the storage power of the battery is lower than the set value of the safe storage power of the battery, the hybrid aircraft is in the power generation system output battery input operation mode; During the take-off and landing phases of the hybrid aircraft, if the storage power of the battery is lower than the set value of the safe storage power of the battery, the hybrid aircraft is in a pure power generation system output operation mode; When the hybrid aircraft is in the cruising stage, if the storage power of the battery is greater than the set value of the battery's safe storage power, the hybrid aircraft is in a pure battery output operation mode or a power generation system battery dual output operation mode.

[0008] Further, when P electric ≥ P fan, the control system enters a pure battery output operation mode, and enters an oil control state at the power point, and the hybrid aircraft switches to a power generation system battery dual output operation mode, a power generation system output battery input operation mode, or a pure power generation system output operation mode, and the power point is P electric - P fan; When P electric < P fan , the piston engine provides power, and the hybrid aircraft switches to the power generation system battery dual output operation mode, the power generation system output battery input operation mode, or the pure power generation system output operation mode; When P electric < P fan and P power = P fan - P electric, the hybrid aircraft enters the pure power generation system output operation mode; When Pelectricity < Pfan and Pgen > (Pfan-Pelectricity), the excess output power of the power generation system is used to charge the battery, and the hybrid aircraft enters the power generation system output and battery input operation mode; When Pelectric < Pfan and Pgen < (Pfan-Pelectric), the integrated microcontroller issues a command to reduce the speed of the drive motor; When Pgen = Pfan, the hybrid aircraft switches to the oil control working mode, and the hybrid aircraft enters the pure power generation system output operation mode; When Pgen>Pfan, the hybrid aircraft switches to the oil control working mode, and the excess output power of the power generation system is used to charge the battery. At this time, Ppower reaches the set safety power Pampere, and enters the power generation system battery dual output operation mode or pure battery output operation mode; When P generator < P fan , the hybrid aircraft switches to the power generation system battery dual output operation mode; When Pgen < Pfan and Pelectric ≥ (Pfan-Pgen), the battery power is consumed to the minimum power point, and the integrated microcontroller issues a command to control the servo angle change to increase the throttle opening of the piston engine to increase the speed of the piston engine; When Pfa < Pfan, and the additional battery provides a maximum output power Pelectric < (Pfan-Pfa), Pfa is at maximum power, and the integrated microcontroller issues a command to reduce the speed of the drive motor; When Pgen+Pelectric ≥ Pfan, the power matching is maintained by reducing the power of Pgen or Pelectric, and the throttle opening of the piston engine, the speed of the piston engine and the output current of the battery are reduced without changing the speed of the ducted fan; When Pgen+Pelectric<Pfan, without changing the rotation speed of the ducted fan, the throttle opening and rotation speed of the piston engine and the output current of the battery are increased.

[0009] Furthermore, when the hybrid aircraft is in the power generation system output and battery input operation mode, if the power generation power of the power generation system is greater than or equal to the output power of the ducted fan, the power generation system charges the battery until the storage power of the battery reaches the set value, and then the hybrid aircraft switches to the pure power generation system output operation mode.

[0010] Furthermore, the high efficiency range of the ducted fan coincides with the high efficiency range of the drive motor.

[0011] Furthermore, the drive motor is a permanent magnet synchronous AC motor.

[0012] Furthermore, the battery is a lithium polymer battery.

[0013] Furthermore, the series hybrid aircraft also includes a cooling system, which includes an air inlet, an air duct, a cooling fan, a heat sink, and an air outlet. The air inlet is used to guide air outside the aircraft into the cooling system. The air duct is connected to the air inlet and is used to transport air to the battery, the integrated starter motor, the piston engine, the integrated microcontroller, the drive motor and the motor drive controller. The cooling fan is installed at the outlet of the air duct to increase the air flow rate. The heat sink is in contact with the battery, the integrated starter motor, the piston engine, the integrated microcontroller, the drive motor and the motor drive controller to transfer heat to the air flowing through the air duct. The air outlet is connected to the air duct to discharge the air that has absorbed heat.

[0014] Furthermore, the integrated microcontroller controls the rectifier bridge to rectify the three-phase AC power generated by the starter-generator into DC power to supply power to the drive motor; the ducted fan is connected to the drive motor through a transmission shaft, and the piston engine drives the starter-generator to generate electricity, and the electrical energy supplies power to the drive motor and replenishes energy for the battery through the integrated microcontroller.

[0015] Furthermore, the starting motor is driven by the piston engine to generate electricity, the integrated microcontroller controls the starting of the piston engine and controls the opening of the throttle through the steering gear to ensure that the power of the piston engine can be output stably, and the piston engine electronic control unit controls the ignition and fuel injection of the piston engine.

[0016] The present invention provides a control method for a series hybrid power aircraft. The series hybrid power aircraft is used to realize the design concept of the control strategy with energy saving, environmental protection, strong robustness, and flexible adaptability to complex working conditions, and the whole machine control strategy is switched in real time with the whole machine system power as the control parameter, so as to improve the energy demand distribution of the series hybrid power aircraft under different working modes and working conditions, improve the operating efficiency of each core component of the system, ensure the robustness of the control strategy, save energy consumption, reduce environmental pollution, and alleviate the energy crisis.

[0017] The control method of the present invention takes the pure electric and hybrid closed-loop control system as the basis for the design of the control strategy of the whole machine of the 16kW series hybrid aircraft, takes the power of the whole machine subsystem as the control parameter of the control strategy, switches the working mode of the whole machine control system according to the different power requirements of the subsystem under different working conditions of the 16kW series hybrid aircraft, improves the power distribution of the whole machine system, and improves the real-time response capability of the whole machine. The present invention improves the energy distribution under different working conditions through real-time monitoring and switching of system power, significantly improves energy efficiency, reduces environmental pollution, and realizes an energy-saving and environmentally friendly control strategy.

[0018] Other features and beneficial effects of the present invention will be described in the following description, and some of the technical features and beneficial effects can be obviously derived from the description or understood by implementing the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, some of the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 is a control block diagram of a series hybrid power aircraft power system provided by an embodiment of the present invention; Figure 2 is a schematic diagram of the principle of a series hybrid power aircraft provided by an embodiment of the present invention; Figure 3 This is a flow chart of a pure electric state control strategy for a series hybrid aircraft provided by an embodiment of the present invention; Figure 4 is a flow chart of a hybrid power state control strategy for a series hybrid power aircraft provided by an embodiment of the present invention; Figure 5 It is a schematic diagram of the principle of a cooling system of a series hybrid aircraft provided by an embodiment of the present invention.

[0021] Reference numerals: 1. Battery; 2. Inverter; 3. Starter motor; 4. Piston engine; 5. Rectifier bridge; 6. K-type thermocouple; 7. Hall speed sensor; 8. Piston engine electronic control unit; 9. Ducted fan; 10. Drive motor; 11. Air inlet; 12. Air duct; 13. Cooling fan; 14. Heat sink; 15. Air outlet; 16. Integrated microcontroller; 17. Power management control module; 18. Motor drive controller; 19. Battery management system; 20. PC host computer. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments; the technical features designed in different implementation modes of the present invention described below can be combined with each other as long as they do not conflict with each other; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0023] In the description of the present invention, it should be understood that the terms "center", "lateral", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In addition, the term "including" and any variation thereof all mean "at least including".

[0024] See also Figures 1 to 5 As shown in the figure, a control method of a series hybrid aircraft is provided in one embodiment of the present invention. The series hybrid aircraft includes a starting system, a power generation system, a monitoring system, an electric drive system, an integrated microcontroller 16, a PC host computer 20 and a power management control module 17.

[0025] The starting system includes a battery 1, an inverter 2, an integrated starting motor 3 and a piston engine 4, the battery 1 is connected to the inverter 2, the inverter 2 is connected to the integrated microcontroller 16, the integrated starting motor 3 is connected to the integrated microcontroller 16, and the piston engine 4 is mechanically connected to the integrated starting motor 3.

[0026] The power generation system and the starting system share the starting motor 3 and the piston engine 4. The power generation system includes a rectifier bridge 5, which is connected to an integrated microcontroller 16. The power generation system can realize the conversion of chemical energy into electrical energy, providing energy for the endurance of the whole machine.

[0027] The monitoring system includes a K-type thermocouple 6 , a Hall speed sensor 7 and a piston engine electronic control unit 8 . The K-type thermocouple 6 and the Hall speed sensor 7 are connected to the piston engine 4 , and the piston engine electronic control unit 8 is connected to an integrated microcontroller 16 .

[0028] The electric drive system includes a ducted fan 9 and a drive motor 10 . The drive motor 10 is connected to the inverter 2 . The ducted fan 9 is connected to the drive motor 10 . The drive motor 10 provides driving force for the ducted fan 9 .

[0029] The PC host computer 20 is connected to the integrated microcontroller 16 through a network cable, and the integrated microcontroller 16 is connected to the power management control module 17. In some embodiments, the integrated microcontroller 16 controls the rectifier bridge 5 to rectify the three-phase AC power generated by the starter motor 3 into DC power to power the drive motor 10. The ducted fan 9 is connected to the drive motor 10 through a transmission shaft, and the battery 1 is connected to the motor drive controller 18 through the integrated microcontroller 16. The motor drive controller 18 inverts the DC power provided by the battery 1 into AC power to power the drive motor 10. The piston engine 4 drives the starter motor 3 to generate electricity, and the electric energy is used to power the drive motor 10 and replenish the energy for the battery 1 through the integrated microcontroller 16. The battery 1 can also be charged by an external device charger. The PC host computer 20 configures the start command and the ignition speed value in the control program interface and sends them to the integrated microcontroller 16. The integrated microcontroller 16 controls the relay of the piston engine electronic control unit 8 to turn on the piston engine electronic control unit 8; controls the starter circuit relay to turn on the battery 1, inverter 2, and starter motor 3 starter loop. The integrated microcontroller 16 runs MTPA and outputs a PWM signal to the inverter 2 of the starting loop in combination with the model-free current prediction control strategy based on ESO (Extended State Observer), so that the starting motor 3 can still provide the maximum torque at the lowest current under the worst working conditions or when its own parameters are greatly affected by losses, so as to achieve efficient starting, and enable the starting motor 3 to drive the piston engine 4 to reach the ignition speed value configured by the PC host computer 20. The integrated microcontroller 16 outputs a PWM signal to control the rotation of the steering gear, thereby changing the throttle opening of the piston engine 4 to the initial ignition opening.

[0030] The power management control module 17 manages the energy distribution of the entire power system according to the command of the PC host computer 20, and controls the output power of the drive motor 10 through the change of the power configuration value. The power management control module 17 can make a judgment based on the remaining power of the battery 1 or the current aircraft flight altitude data collected by the altitude sensor, and control the integrated microcontroller 16 to adjust the speed of the piston engine 4. The integrated microcontroller 16 changes the rotation angle of the servo according to the load demand to control the size of the throttle of the piston engine 4 to control the output power of the starting motor 3.

[0031] In some embodiments, the energy acquisition of the drive motor 10 can be directly powered by the battery 1, and another is the power generated by the piston engine 4 driving the integrated motor 3. The drive motor 10 provides a power source for the hybrid aircraft. The drive motor 10 drives the ducted fan 9 to generate thrust and provide kinetic energy for the hybrid aircraft to move forward; the drive motor 10 is preferably a permanent magnet synchronous AC motor with a high power-to-weight ratio to meet aviation requirements. The high efficiency range of the ducted fan 9 coincides with the high efficiency range of the drive motor 10. The efficiency of the ducted fan 9 is divided into zones, and the efficiency of the ducted fan 9 is different at different speeds. Generally, the efficiency is the highest at fixed cruise, which is greater than 0.8; the drive motor 10 also has an efficiency range. When the aircraft is cruising, the speed of the drive motor 10 remains constant. At this time, the high efficiency range of the drive motor 10 is overlapped with the high efficiency range of the ducted fan 9, which improves energy utilization and reduces useless work, so as to maximize energy utilization and match to meet cruise requirements as the basic principle.

[0032] Define the power generation of the power generation system as Pfa, the storage power of battery 1 as Pdian, and the output power of ducted fan 9 as Pfan. The calculation formula of the storage power Pdian of battery 1 is: Pdian = battery 1 voltage (V) * battery 1 capacity (Ah); the calculation formula of the power generation of the power generation system Pfa is: Pfa = piston engine 4 speed (n1) * power generation conversion constant of the starter motor 3 (K); the calculation formula of the output power Pfan of the electric drive system is: Pfan = drive motor 10 speed (n2) * ducted fan 9 load (Tn) / 9550.

[0033] The control method of the series hybrid aircraft includes the following steps: according to P generation, P power and P fan, the hybrid aircraft is controlled to switch between the power generation system battery dual output operation mode, the power generation system output battery input operation mode, the pure battery output operation mode and the pure power generation system output operation mode. The power management control module 17 controls the motor drive controller 18 through the integrated microcontroller 16. The power management control module 17 monitors the working conditions of each system and adjusts the control strategy in time to ensure the safety and reliability of each system. For example, when the temperature of the motor drive controller 18 is higher than the set value, the power management control module 17 starts to limit the output power through the integrated microcontroller 16 to reduce the kinetic energy of the drive motor 10, thereby reducing the flight speed of the hybrid aircraft.

[0034] The power generation system battery dual output operation mode means that the battery 1 and the starting motor 3 work at the same time. The battery 1 actively outputs electric energy to power the drive motor 10 and rotate the ducted fan 9; and the piston engine 4 drives the starting motor 3 to output electric energy, which, after passing through the rectifier bridge 5 controlled by the integrated microcontroller 16, powers the drive motor 10 and rotates the ducted fan 9, thereby realizing the power generation system battery dual output operation mode.

[0035] The power generation system output battery input operation mode means that the starting motor 3 is working. The piston engine 4 drives the starting motor 3 to output electric energy, which, after passing through the rectifier bridge 5 controlled by the integrated microcontroller 16, supplies power to the drive motor 10 to drive the ducted fan 9, and the excess electric energy is used to charge the battery 1, thereby realizing the power generation system output battery input operation mode.

[0036] The pure battery output operation mode means that the battery 1 works and the battery 1 actively outputs electric energy to power the drive motor 10 to rotate the ducted fan 9, thereby realizing the pure battery output operation mode.

[0037] The pure power generation system output operation mode means that the starter motor 3 is working. The piston engine 4 drives the starter motor 3 to output electric energy, which, after passing through the rectifier bridge 5 controlled by the integrated microcontroller 16, supplies power to the drive motor 10 to drive the ducted fan 9, without any excess electric energy, thereby realizing the pure power generation system output operation mode.

[0038] The control method of the present invention designs the working mode based on the concept of energy saving and environmental protection of series hybrid aircraft, that is, if the storage power of battery 1 of the hybrid aircraft is greater than the output power of the electric drive system, a pure battery output operation mode is adopted during the take-off and landing stages, and the hybrid aircraft adopts the power generation system battery dual output operation mode or the power generation system output battery input operation mode during the high-altitude cruising stage. The length of the working mode in each stage is considered based on the storage power of battery 1, the power generation power of the power generation system, the output power of the electric drive system and other powers.

[0039] During the take-off and landing phases of the hybrid aircraft, if the storage power of battery 1 is greater than the output power of the electric drive system, battery 1 will supply power to the drive motor 10 alone, thus meeting environmental protection requirements and reducing noise and exhaust pollution around the airport; when the hybrid aircraft reaches a predetermined altitude and starts cruising, the integrated microcontroller 16 controls the starter system relay to be turned on, and the battery 1 supplies energy to the starter motor 3 through the inverter 2, driving the piston engine 4. After the piston engine 4 is ignited successfully, the integrated microcontroller 16 controls the starter system relay to be disconnected and the generator system relay to be turned on, and the piston engine 4 drives the starter motor 3 to start generating electricity, providing electrical energy for the drive motor 10 and battery 1, effectively increasing the range and endurance of the hybrid aircraft. The hybrid control module controls the piston engine 4 to always work in an efficient range, saving fuel consumption.

[0040] Further, when the maximum output power of the power generation system is less than the output power of the ducted fan 9 and the storage power of the battery 1 is higher than the set value of the safe storage power of the battery 1, the hybrid aircraft is in the power generation system battery dual output operation mode; When the output power of the power generation system is greater than the output power of the ducted fan 9 and the storage power of the battery 1 is lower than the set value of the safe storage power of the battery 1, the hybrid aircraft is in the power generation system output and battery input operation mode; When the hybrid aircraft is in the take-off and landing phases, if the storage power of the battery 1 is lower than the set value of the safe storage power of the battery 1, the hybrid aircraft is in the pure power generation system output operation mode; When the hybrid aircraft is in the cruising stage, if the storage power of battery 1 is greater than the set value of the safe storage power of battery 1, the hybrid aircraft is in a pure battery output operation mode or a power generation system battery dual output operation mode.

[0041] Further, when P electric ≥ P fan , that is, the storage power of battery 1 is sufficient to maintain the output power of the electric drive system, the control system enters the pure battery output operation mode, and enters the oil control state at the power point, and the hybrid aircraft switches to the power generation system battery dual output operation mode, the power generation system output battery input operation mode or the pure power generation system output operation mode, and the power point is P electric - P fan; When P electric < P fan , that is, the storage power of the battery 1 is insufficient to maintain the output power of the electric drive system, the piston engine 4 provides power, and the hybrid aircraft switches to the power generation system battery dual output operation mode, the power generation system output battery input operation mode, or the pure power generation system output operation mode; When P electric < P fan and P power = P fan - P electric, the power generation system has no extra output power to charge battery 1, and the hybrid aircraft enters the pure power generation system output operation mode; When Pelectricity < Pfan and Pgen > (Pfan-Pelectricity), the excess output power of the power generation system is used to charge battery 1, and the hybrid aircraft enters the power generation system output and battery input operation mode; When P electric < P fan and P power < (P fan - P electric ), P electric is the maximum power that the battery 1 can output, and the integrated microcontroller 16 issues a command to reduce the speed of the drive motor 10; When Pfa = Pfan, that is, the power generation power Pfa of the power generation system is sufficient to maintain the output power Pfan of the electric drive system, the hybrid aircraft switches to the oil control working mode, and the hybrid aircraft enters the pure power generation system output operation mode; When Pfa>Pfan, that is, the power generation power Pfa of the power generation system is sufficient to maintain the output power Pfan of the electric drive system, the hybrid aircraft switches to the oil control working mode, and the excess output power of the power generation system is used to charge the battery 1. At this time, Pdian reaches the set safety power Pan, and enters the power generation system battery dual output operation mode or pure battery output operation mode; When Pfa < Pfan, that is, the power generation power Pfa of the power generation system is not enough to maintain the output power of the electric drive system, the power system needs additional battery 1 to provide power, and the hybrid aircraft switches to the power generation system battery dual output operation mode; When Pgen < Pfan and Ppower ≥ (Pfan-Pgen), the power of the battery 1 is consumed to the minimum power point (Pfan-Pgen), and the integrated microcontroller 16 issues an instruction to control the change of the steering gear angle to increase the throttle opening of the piston engine 4, so as to increase the rotation speed of the piston engine 4; When Pfa < Pfan, and the additional battery 1 provides a maximum output power Pelectric < (Pfan-Pfa), Pfa is the maximum power, and the integrated microcontroller 16 issues a command to reduce the speed of the drive motor 10; When Pgen+Pelectricity≥Pfan, the working conditions of Pgen≥Pfan and Pelectricity≥Pfan are no longer discussed, and the power matching is maintained by reducing the power of Pgen or Pelectricity, and the throttle opening of the piston engine 4 and the speed of the piston engine 4 and the output current of the battery 1 are reduced without changing the speed of the ducted fan 9; When Pgen+Pelectric<Pfan, the operating conditions of Pgen<Pfan and Pelectric<Pfan are no longer discussed. Without changing the rotation speed of the ducted fan 9, the throttle opening and rotation speed of the piston engine 4 and the output current of the battery 1 are increased.

[0042] Furthermore, when the hybrid aircraft is in the power generation system output and battery input operation mode, if the power generation power of the power generation system is greater than or equal to the output power of the ducted fan 9, the power generation system charges the battery 1 until the storage power of the battery 1 reaches the set value, and then the hybrid aircraft switches to the pure power generation system output operation mode.

[0043] In some embodiments, the upper computer interface of the aircraft control panel sends a speed command for the drive motor 10, the motor drive controller 18 receives the speed command for the drive motor 10, the motor drive controller 18 matches the output power of the ducted fan 9 according to the drive motor 10, the power management control module 17 controls the opening of the power line between the battery 1 and the drive motor 10, the battery 1 supplies power to the drive motor 10, and the battery management system 19 matches the output power of the battery 1 according to the output power of the ducted fan 9, finally forming a closed-loop pure electric system, and using the storage power of the battery 1 as the control parameter to switch the power generation system battery dual output operation mode, the power generation system output battery input operation mode, the pure battery output operation mode or the pure power generation system output operation mode.

[0044] When the series hybrid aircraft switches to a non-pure battery output operating mode, the upper computer interface of the aircraft control panel sends a speed command for the drive motor 10, and the integrated microcontroller 16 detects that the storage power Pelectric of the battery 1 is difficult to maintain the output power Pfan of the ducted fan 9. Without changing the speed, the power generation power of the power generation system is distributed. On the one hand, the power generation system maintains the power generation state, and on the other hand, it adjusts the servo rotation angle to control the throttle opening and power generation power of the piston engine 4. The power generation system enters an oil control closed-loop control state, and the control system adjusts the operating mode of the entire system (power generation system battery dual output operating mode, power generation system output battery input operating mode, pure battery output operating mode, and pure power generation system output operating mode) according to the relationship between the power generation power Pfa of the power generation system, the storage power Pelectric of the battery 1, and the output power Pfan of the ducted fan 9.

[0045] In some embodiments, the drive motor 10 is a permanent magnet synchronous AC motor to meet aviation requirements.

[0046] In some embodiments, the battery 1 is a lithium polymer battery 1. The battery 1 can be composed of single lithium batteries 1 connected in series and parallel to form a pack, and then several packs are connected in series to form a battery group 1. The battery 1 is managed by a battery management system 19, and the battery management system 19 monitors the voltage, current, temperature rise, etc. of the battery 1 in real time. The battery 1 can be replenished with energy by a charger and connected to the motor drive controller 18 through an integrated microcontroller 16 to be inverted into alternating current. The battery management system 19 manages the battery 1, and the power management control module 17 can determine whether to increase or decrease the power output of the piston engine 4 with the rotating starter motor 3 according to the storage power of the battery 1.

[0047] Furthermore, the starting motor 3 is driven by the piston engine 4 to generate electricity, the integrated microcontroller 16 controls the starting of the piston engine 4 and controls the opening of the throttle through the steering gear to ensure that the power of the piston engine 4 can be stably output, and the piston engine electronic control unit 8 controls the ignition and fuel injection of the piston engine 4, and collects engine speed information and transmits it to the integrated microcontroller 16 through the RS-232 interface serial communication. The RS-232 standard interface (also known as EIARS-232) is one of the commonly used serial communication interface standards. It was jointly formulated by the Electronic Industry Association (EIA) of the United States, Bell System, modem manufacturers and computer terminal manufacturers in 1970. Its full name is "Technical Standard for Serial Binary Data Exchange Interface between Data Terminal Equipment (DTE) and Data Communication Equipment (DCE)".

[0048] The four operating modes of the power generation system battery dual output operation mode, the power generation system output battery input operation mode, the pure battery output operation mode and the pure power generation system output operation mode can be classified into two modes: pure battery output mode and non-pure battery output mode. According to the design concept of hybrid aircraft, the pure battery output mode is maintained as much as possible during the aircraft operation phase, and the non-pure battery output mode is switched to according to the change of the storage power of battery 1. If P electric ≥ P fan, that is, the storage power of battery 1 is sufficient to maintain the output power of the electric drive system, the control system enters the pure battery output mode and switches to the non-pure battery output mode when P electric = P fan; if P electric < P fan, that is, the storage power of battery 1 is not enough to maintain the output power of the electric drive system, the hybrid power system needs the piston engine 4 to provide power, and the hybrid aircraft operates in the non-pure battery output mode.

[0049] The battery 1, the drive motor 10, the integrated microcontroller 16, the power management control module 17, the ducted fan 9, etc. form a closed-loop pure electric system, which works in a pure battery output mode. The pure battery output mode control process is as follows: 1. The aircraft control panel host computer interface issues a speed command for the drive motor 10.

[0050] 2. The integrated microcontroller 16 receives the speed command of the drive motor 10 through LwIP protocol network communication, and calculates the output power of the ducted fan 9 that the drive motor 10 should match.

[0051] 3. The power management control module 17 controls the opening of the power line between the battery 1 and the drive motor 10 , and the battery 1 supplies power to the drive motor 10 .

[0052] 4. The battery management system 19 matches the output power of the battery 1 according to the output power of the ducted fan 9 calculated by the integrated microcontroller 16, and controls the battery 1 to output electrical energy.

[0053] 5. A closed-loop pure electric system is formed, and the storage power of battery 1 is used as the control parameter to switch to a non-pure battery output operation mode: (1) If the storage power of the battery 1 meets the output power of the ducted fan 9, the battery 1, the drive motor 10, the integrated microcontroller 16, the power management control module 17, the ducted fan 9, etc. form a closed-loop pure electric system, and the output power of the ducted fan 9 and the battery 1 is adjusted in real time according to the speed command of the drive motor 10 of the upper computer; (2) If the power stored in the battery 1 does not meet the output power of the ducted fan 9, the operation mode of the hybrid aircraft is switched to the non-pure battery output operation mode, and the pure battery output mode is terminated.

[0054] The battery 1, the drive motor 10, the integrated microcontroller 16, the power management control module 17, the ducted fan 9, etc. form a closed-loop pure electric system, and the piston engine 4, the starter motor 3, the integrated microcontroller 16, the power management control module 17, the ducted fan 9, etc. form a closed-loop oil control system. The two systems work together to make the 1-powered aircraft work in a non-pure battery output mode. The non-pure battery output mode control process is as follows: 1. The aircraft control panel host computer interface issues a speed command for the drive motor 10.

[0055] 2. The integrated microcontroller 16 calculates the power value that the ducted fan 9 needs to match according to the speed instruction, and communicates with the battery management system 19 to detect that the storage power Pelectric of the battery 1 is difficult to maintain the output power Pfan of the ducted fan 9. Under the premise of not changing the speed, the power generation power Pfa of the power generation system is allocated.

[0056] 3. The power generation system maintains the power generation state on the one hand, and on the other hand, the integrated microcontroller 16 adjusts the steering gear rotation angle to control the throttle opening and power generation of the piston engine 4, and the power generation system enters the oil control closed-loop control state.

[0057] 4. According to the relationship among the power generation power P of the power generation system, the storage power P of the battery 1 and the output power P of the ducted fan 9, the operation mode of the whole system is adjusted (at this time, P is smaller than P ).

[0058] In some embodiments, Figure 5 As shown, the series hybrid aircraft also includes a cooling system, which includes an air inlet 11, an air duct 12, a cooling fan 13, a heat sink 14, and an air outlet 15. The air inlet 11 is used to guide the air outside the aircraft into the cooling system. The air duct 12 is connected to the air inlet 11 and is used to transport air to the battery 1, the integrated starter motor 3, the piston engine 4, the integrated microcontroller 16, the drive motor 10 and the motor drive controller 18. The cooling fan 13 is installed at the outlet of the air duct 12 to increase the air flow rate. The heat sink 14 is in contact with the battery 1, the integrated starter motor 3, the piston engine 4, the integrated microcontroller 16, the drive motor 10 and the motor drive controller 18, and is used to transfer heat to the air flowing through the air duct 12. The air outlet 15 is connected to the air duct 12 to discharge the air that has absorbed heat.

[0059] The present invention provides a control method for a series hybrid power aircraft. The series hybrid power aircraft is used to realize the design concept of the control strategy with energy saving, environmental protection, strong robustness, and flexible adaptability to complex working conditions, and the whole machine control strategy is switched in real time with the whole machine system power as the control parameter, so as to improve the energy demand distribution of the series hybrid power aircraft under different working modes and working conditions, improve the operating efficiency of each core component of the system, ensure the robustness of the control strategy, save energy consumption, reduce environmental pollution, and alleviate the energy crisis.

[0060] The present invention needs to overcome the defects of complex structure, high cost and low efficiency of small and medium power hybrid aircraft, introduces an integrated starter motor 3, a ducted fan 9, an integrated microcontroller 16 and a low-cost air-cooled cooling system, proposes a new configuration of a series hybrid aircraft, improves the energy demand distribution of the hybrid system under different working modes and conditions, and proposes a specific high-efficiency model-free control strategy for the integrated starter motor 3 and the drive motor 10 that does not depend on motor parameters, realizes efficient control of the core components of the hybrid aircraft, and improves the operating efficiency of each part of the system.

[0061] The control method of the present invention takes the pure electric and hybrid closed-loop control system as the basis for the design of the control strategy of the whole machine of the 16kW series hybrid aircraft, takes the power of the whole machine subsystem as the control parameter of the control strategy, switches the working mode of the whole machine control system according to the different power requirements of the subsystem under different working conditions of the 16kW series hybrid aircraft, improves the power distribution of the whole machine system, and improves the real-time response capability of the whole machine. The present invention improves the energy distribution under different working conditions through real-time monitoring and switching of system power, significantly improves energy efficiency, reduces environmental pollution, and realizes an energy-saving and environmentally friendly control strategy.

[0062] The serial hybrid aircraft of the present invention has an exquisite design, light weight, simple structure, low cost and high efficiency, which is specifically embodied in: 1. Combine the starter motor of the rotating engine in the traditional aircraft and the generator in the power generation system into one, and use a high-power ratio permanent magnet synchronous motor to play the functions of both at the same time, saving space and improving efficiency.

[0063] 2. The starting-generating integrated motor 3 is provided with an MTPA control strategy and a voltage-stabilizing weak-field control strategy that are respectively adapted to starting conditions and generating conditions, and an ESO-based model-free current prediction control strategy is introduced into the control strategies under both conditions to ensure efficient control of the control strategy under complex and harsh conditions and changes in motor loss parameters.

[0064] 3. Provide a dual closed-loop vector control strategy for the drive motor 10, in which the outer speed loop adopts a PI controller and the inner current loop introduces an ESO-based model-free predictive controller to efficiently and stably control the speed of the drive motor 10.

[0065] 4. Use a two-cylinder piston engine with high combustion efficiency and low fuel consumption 4, so that it can work at the design point for a long time to improve efficiency, save energy and reduce emissions, and achieve green aviation.

[0066] 5. The ducted fan 9 is used as the driving device of the aircraft, which has high aerodynamic efficiency and good safety performance, and is very suitable for the application scenarios of small and medium-power aircraft.

[0067] 6. The cooling system adopts air cooling, which has a simple structure and does not require many instruments and devices. It only needs to open an air duct 12 inside the aircraft to reduce the weight of the aircraft while ensuring that the cooling performance is sufficient to support small and medium-power aircraft.

[0068] In addition, those skilled in the art should understand that, although there are many problems in the prior art, each embodiment or technical solution of the present invention can be improved in only one or several aspects, without having to solve all the technical problems listed in the prior art or background technology at the same time. Those skilled in the art should understand that the content not mentioned in a claim should not be used as a limitation on the claim.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method for a series hybrid aircraft, characterized in that: The series hybrid power aircraft includes a starting system, a power generation system, a monitoring system, an electric drive system, an integrated microcontroller, a PC host computer and a power management control module; The starting system comprises a battery, an inverter, an integrated starter motor and a piston engine, wherein the battery is connected to the inverter, the inverter is connected to the integrated microcontroller, the integrated starter motor is connected to the integrated microcontroller, and the piston engine is mechanically connected to the integrated starter motor; The power generation system and the starting system share the integrated starting motor and the piston engine, and the power generation system includes a rectifier bridge connected to the integrated microcontroller; The monitoring system comprises a K-type thermocouple, a Hall speed sensor and a piston engine electronic control unit, wherein the K-type thermocouple and the Hall speed sensor are connected to the piston engine, and the piston engine electronic control unit is connected to the integrated microcontroller; The electric drive system includes a ducted fan and a drive motor, wherein the drive motor is connected to the inverter, the ducted fan is connected to the drive motor, and the drive motor provides driving force for the ducted fan; The PC host computer is connected to the integrated microcontroller via a network cable, and the integrated microcontroller is connected to the power management control module; The power generation power of the power generation system is defined as Pfa, the storage power of the battery is defined as Pdian, the output power of the ducted fan is defined as Pfan, and the control method of the series hybrid aircraft includes the following steps: The hybrid aircraft is switched among a power generation system battery dual output operation mode, a power generation system output battery input operation mode, a pure battery output operation mode and a pure power generation system output operation mode according to P generation, P power and P fan control.

2. The control method of a series hybrid aircraft according to claim 1, characterized in that: When the maximum output power of the power generation system is less than the output power of the ducted fan, and the storage power of the battery is higher than the set value of the safe storage power of the battery, the hybrid aircraft is in the power generation system battery dual output operation mode; When the output power of the power generation system is greater than the output power of the ducted fan, and the storage power of the battery is lower than the set value of the safe storage power of the battery, the hybrid aircraft is in the power generation system output battery input operation mode; During the take-off and landing phases of the hybrid aircraft, if the storage power of the battery is lower than the set value of the safe storage power of the battery, the hybrid aircraft is in a pure power generation system output operation mode; When the hybrid aircraft is in the cruising stage, if the storage power of the battery is greater than the set value of the battery's safe storage power, the hybrid aircraft is in a pure battery output operation mode or a power generation system battery dual output operation mode.

3. The control method of a series hybrid aircraft according to claim 2, characterized in that: When P electric ≥ P fan, the control system enters the pure battery output operation mode, and enters the oil control state at the power point, and the hybrid aircraft switches to the power generation system battery dual output operation mode, the power generation system output battery input operation mode or the pure power generation system output operation mode, and the power point is P electric - P fan; When P electric < P fan , the piston engine provides power, and the hybrid aircraft switches to the power generation system battery dual output operation mode, the power generation system output battery input operation mode, or the pure power generation system output operation mode; When P electric < P fan and P power = P fan - P electric, the hybrid aircraft enters the pure power generation system output operation mode; When Pelectricity < Pfan and Pgen > (Pfan-Pelectricity), the excess output power of the power generation system is used to charge the battery, and the hybrid aircraft enters the power generation system output and battery input operation mode; When Pelectric < Pfan and Pgen < (Pfan-Pelectric), the integrated microcontroller issues a command to reduce the speed of the drive motor; When Pgen = Pfan, the hybrid aircraft switches to the oil control working mode, and the hybrid aircraft enters the pure power generation system output operation mode; When P generator > P fan, the hybrid aircraft switches to the oil control working mode, and the excess output power of the power generation system is used to charge the battery. At this time, P power reaches the set safety power P ampere, and enters the power generation system battery dual output operation mode or pure battery output operation mode; When P generator < P fan , the hybrid aircraft switches to the power generation system battery dual output operation mode; When Pgen < Pfan and Pelectric ≥ (Pfan-Pgen), the battery power is consumed to the minimum power point, and the integrated microcontroller issues a command to control the servo angle change to increase the throttle opening of the piston engine to increase the speed of the piston engine; When Pfa < Pfan, and the additional battery provides a maximum output power Pelectric < (Pfan-Pfa), Pfa is at maximum power, and the integrated microcontroller issues a command to reduce the speed of the drive motor; When Pgen+Pelectric ≥ Pfan, the power matching is maintained by reducing the power of Pgen or Pelectric, and the throttle opening of the piston engine, the speed of the piston engine and the output current of the battery are reduced without changing the speed of the ducted fan; When Pgen+Pelectric<Pfan, without changing the rotation speed of the ducted fan, the throttle opening and rotation speed of the piston engine and the output current of the battery are increased.

4. The control method of a series hybrid aircraft according to claim 2, characterized in that: When the hybrid aircraft is in the power generation system output and battery input operation mode, if the power generation power of the power generation system is greater than or equal to the output power of the ducted fan, the power generation system charges the battery until the storage power of the battery reaches the set value, and then the hybrid aircraft switches to the pure power generation system output operation mode.

5. The control method of a series hybrid aircraft according to claim 1, characterized in that: The high efficiency range of the ducted fan coincides with the high efficiency range of the drive motor.

6. The control method of a series hybrid aircraft according to claim 1, characterized in that: The driving motor is a permanent magnet synchronous AC motor.

7. The control method of a series hybrid aircraft according to claim 1, characterized in that: The battery is a lithium polymer battery.

8. The control method of a series hybrid aircraft according to claim 1, characterized in that: The series hybrid aircraft also includes a cooling system, which includes an air inlet, an air duct, a cooling fan, a heat sink, and an air outlet. The air inlet is used to guide air outside the aircraft into the cooling system. The air duct is connected to the air inlet and is used to transport air to the battery, the integrated starter motor, the piston engine, the integrated microcontroller, the drive motor and the motor drive controller. The cooling fan is installed at the outlet of the air duct and is used to increase the air flow rate. The heat sink is in contact with the battery, the integrated starter motor, the piston engine, the integrated microcontroller, the drive motor and the motor drive controller and is used to transfer heat to the air flowing through the air duct. The air outlet is connected to the air duct and is used to discharge the air that has absorbed heat.

9. The control method of a series hybrid aircraft according to claim 1, characterized in that: The integrated microcontroller controls the rectifier bridge to rectify the three-phase AC power generated by the starter-generator into DC power to supply power to the drive motor; the ducted fan is connected to the drive motor through a transmission shaft, and the piston engine drives the starter-generator to generate electricity. The electric energy supplies power to the drive motor and replenishes energy for the battery through the integrated microcontroller.

10. The control method of a series hybrid aircraft according to claim 1, characterized in that: The starter-generator motor is driven by the piston engine to generate electricity. The integrated microcontroller controls the starting of the piston engine and controls the opening of the throttle through the steering gear to ensure that the power of the piston engine can be output stably. The piston engine electronic control unit controls the ignition and fuel injection of the piston engine.

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