All-electric engine self-powered system architecture and control strategy thereof

Abstract

The invention discloses an all-electric engine self-powered system architecture and a control strategy thereof, and belongs to the field of aircraft power supply systems. The structure of the all-electric engine self-powered system is composed of an aero-engine, two starting generators, two sets of AC / DC starting power generation controllers, two 270V high-voltage DC bus bars, an electric energy storage device, a 28V low-voltage DC bus bar, a multi-port bidirectional DC / DC converter, a multi-port bidirectional DC / AC inverter, an oil pump motor and an electric actuator. The self-powered system is isolated from an external power supply system. And controlling the self-powered system according to the control strategy. The self-powered system architecture and the control strategy can effectively enhance the reliability and the stability of an engine key load power supply network, and improve the power supply quality of the power supply system; voltage fluctuation on the high-voltage bus bar is suppressed; energy feedback and efficient utilization are realized; the system cost and complexity are reduced, and the fault-tolerant capability and reliability of the self-powered system can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of aircraft power supply systems, and in particular to an all-electric engine self-powered system architecture and its control strategy. Background Technology

[0002] In traditional aircraft engine power supply systems, the power consumption is generally no more than 200W, mainly used to power the computer of the control system, drive servo valves, and power sensors. These systems are typically supplied by multiple independent power sources provided by the aircraft. Due to the low voltage and small current, the system's power supply safety requirements can usually be guaranteed simply by connecting multiple power sources in parallel. More-electric / all-electric aircraft engine systems are gradually replacing traditional hydraulic and pneumatic energy sources with electrical energy, evolving into more-electric engine systems.

[0003] The new changes bring new challenges. On the one hand, due to the high voltage and large current, if the aircraft still manages the engine power system, it will cause a huge increase in power cable length, weight, and power dissipation. On the other hand, due to the high system safety requirements, any single point failure cannot cause functional degradation, and the generator redundancy at the system source end is limited. Therefore, it is necessary to study the redundancy architecture of high voltage DC microgrids and develop an independent aero-engine power supply system to ensure that the overall safety of the system meets the requirements.

[0004] Advanced engine companies and research institutions abroad are conducting research on multi-electric / all-electric engine technology, replacing hydraulic and pneumatic actuation systems with electric actuators, and replacing starters and generators with starter generators. This unifies the secondary energy of the engine into electrical energy, simplifies piping layout, and improves reliability. The control system integrates control, protection, fault diagnosis, and health management functions, providing fault warnings for critical components and greatly improving system maintainability. 270V HVDC is widely used as the main voltage level power supply system in the US Army LHX, Navy A-12, and F-35, with the F-35 having a total generator capacity of 250kW. Rolls-Royce designed a dual-wire 270V HVDC power supply system grid simulation experimental platform. The system includes one main generator and one APU generator, as well as other secondary power supplies, emergency power supplies, and adjustable resistive loads, to verify the dynamic performance of the grid structure and the impact of energy storage devices on the overall system.

[0005] Patent CN112532128A (A High-Power Composite Brushless Starting and Generating System for Aviation and Its Control Method) is based on a single electrically excited doubly salient reluctance motor. It achieves switching between three functions—starting, generating, and driving an external brushless motor—through a multiplexed starting controller. Although it can output AC and DC dual-mode power, the system architecture is still a single motor, uses a separate controller, and does not have a dual-redundancy configuration. Furthermore, its AC and DC outputs are directly connected to the airborne busbar, and the self-powered circuit has no electrical isolation design from the external airborne power supply. The system does not have a multi-port bidirectional converter to realize the electric actuator braking energy recovery, nor does it have a topology design that makes the self-powered system independent of the external power supply.

[0006] Foreign countries have a leading advantage in the control and management technology of aircraft power supply system grids. Domestic research on engine microgrids is relatively limited. Nanjing University of Aeronautics and Astronautics, in collaboration with the Chinese Academy of Sciences, has conducted research on a distributed power supply system for a certain type of engine. The system includes two 170kW starter generators, lithium-ion batteries, a 540VDC bus voltage, and a dual-channel grid that supplies power to the control systems of each engine, including the electric fuel pump, electric fan, and electric oxygen pump. However, this power supply system is currently in the principle verification stage. Full digital simulations have been conducted on the control strategy, and the control system prototype is still in the demonstration phase.

[0007] Overall, there is limited research on the self-powered system architecture of multi-electric engines, and the technology is not yet mature. There is an urgent need to carry out relevant research to support the development of multi-electric / all-electric aircraft. The research results can be further applied to fields such as multi-rotor UAVs and all-electric propulsion fixed-wing aircraft. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of the prior art by proposing an all-electric engine self-powered system architecture and its control strategy. This architecture reduces the size and weight of the airborne power supply system, increases the safety margin of the engine's critical loads, rationally allocates energy in the power supply system to achieve optimal efficiency, and improves the stability and power quality of the aero-engine power supply system.

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: An all-electric engine self-powered system architecture is provided, comprising two starter generators, a self-powered system, and an aero-engine; the self-powered system is isolated from the external power system, achieving dual redundancy and dual-circuit power supply; The two starter generators are mechanically connected to the aircraft engine. The starter generators are dual-stator winding generators, including a dual-winding induction motor and a three-stage motor. The three-stage motor is a motor that supplies power to the engine's self-power supply system and the main exciter after the auxiliary excitation winding motor has been expanded in power generation capacity. The self-powered system includes two sets of AC / DC starter generator controllers, two 270V high-voltage DC busbars, a 28V low-voltage DC busbar, an energy storage device, a multi-port bidirectional DC / DC converter, a multi-port bidirectional DC / AC inverter, an oil pump motor, and an electric actuator. External AC power is converted into 270V DC power by the two sets of AC / DC starter generator controllers. The two 270V DC power lines are connected in parallel, and the energy storage device is connected to the parallel DC bus. The 270V DC power provides 28V DC power to the load through the multi-port bidirectional DC / DC converter, and powers the oil pump motor and electric actuator through the multi-port bidirectional DC / AC inverter.

[0010] Furthermore, the starter generator consists of two sets of three-phase windings with midpoint isolation. One set supplies power to airborne equipment other than the engine, i.e., external power supply, while the other set supplies power to the engine's electrical equipment, i.e., self-power supply. This ensures that the self-power supply system and the external power supply system are electrically isolated from each other and do not interfere with each other, thereby increasing the reliability of the aircraft's power supply.

[0011] Furthermore, during the engine start-up phase, the starting generator and AC / DC starting generator controller are powered by an energy storage device connected to dual 270V high-voltage DC busbars to control and drive the motor. The starting generator drives the engine from a standstill to the ignition speed and helps the engine reach the generator speed through the self-sustaining phase.

[0012] Furthermore, during the power generation phase, the aircraft engine drives the starter generator to rotate at high speed. The starter generator generates high-frequency, high-voltage AC power, which is rectified to 270V by the AC / DC starter generator controller to supply power to the load and to the energy storage device for storage.

[0013] Furthermore, the 270V high-voltage DC busbar and the 28V low-voltage DC busbar are electrically isolated by an isolated multi-port bidirectional DC / DC converter to prevent a fault in one circuit from affecting the other. The 270V high-voltage DC busbar is isolated from the oil pump and electric actuator by an isolated multi-port bidirectional DC / AC converter to ensure that the load operates normally when the 270V busbar fails.

[0014] Furthermore, the energy storage device uses a high-voltage battery and a supercapacitor as the power supply for the AC / DC inverter during startup and as an emergency power supply for the load in the engine system, thereby improving the reliability of the self-powered system.

[0015] A control strategy for a self-powered all-electric motor system architecture includes the following control steps: Step S1: The self-powered system controls power generation, the storage device supplies power, and the generator starts to drive the engine to the power generation speed; Step S2: When the busbar is working normally, the load is running normally and energy is fed back to the power storage device. Step S3: When one of the 270V high-voltage DC busbars fails, the fault is disconnected, and the load is powered by the other 270V high-voltage DC busbar, realizing the dual redundancy power supply of the self-powered system; Step S4: When the AC / DC starter generator controller fails, neither of the two 270V busbars can supply power normally. The faulty AC / DC starter generator controller is disconnected, and the energy storage device supplies power to the faulty 270V high-voltage DC busbar through the multi-port bidirectional DC / DC converter to provide emergency power to the load in the engine system.

[0016] Compared with the prior art, the present invention, employing the above technical solution, has the following beneficial effects: (1) The present invention proposes an all-electric engine self-powered system architecture and its control strategy. It adopts an independent power supply design for the all-electric engine power supply system, which is completely electrically isolated from the external power supply system and is not affected by the external power supply system. It can effectively enhance the reliability and stability of the power supply network for the engine's critical loads and improve the power quality of the power supply system.

[0017] (2) The present invention proposes an all-electric engine self-powered system architecture and its control strategy, which adopts a dual high-voltage DC bus bar and a multi-port converter design. When the aircraft is working normally, the load is powered by 270V high-voltage DC power generated by two starter generators. The 28V low-voltage bus bar is connected to the two high-voltage DC busbars through a multi-port DC / DC converter. At the same time, the energy storage device is used as a backup power source to supply power to the high-voltage side and the low-voltage side, suppressing voltage fluctuations on the 270V high-voltage bus bar.

[0018] (3) The self-powered power supply system architecture and control strategy of the all-electric engine proposed in this invention can recover the electrical energy fed back to the motor controller and put it into the energy storage device when the constant power load, such as the oil pump motor and electric actuator, is braking or running in multiple quadrants, so as to realize the functions of energy feedback and efficient utilization.

[0019] (4) The self-powered power supply system architecture and control strategy of the all-electric engine proposed in this invention adopts dual 270V high-voltage busbar redundancy and multi-port converter design as functional redundancy. Compared with direct redundancy, it reduces system cost and complexity. The 270V high-voltage busbar redundancy design as backup is in a dormant state when the system is working normally, and will not affect the original reliability of the system. It is only activated when the working busbar fails, which can effectively improve the fault tolerance and reliability of the self-powered system. Attached Figure Description

[0020] Figure 1 This invention relates to the architecture of a self-powered all-electric motor system. Figure 2 This is a block diagram of the control strategy for the all-electric engine self-powered system of the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] The present invention proposes a self-powered all-electric engine system architecture as follows: Figure 1 As shown, the architecture includes one aircraft engine, two starter generators, and a self-powered system. The self-powered system is isolated from the external power system, achieving dual redundancy and dual-circuit power supply. The two starter generators are mechanically connected to the aircraft engine and are some form of dual-stator or dual-stator winding generator, including but not limited to dual-winding induction motors and three-stage motors. The three-stage motor is a motor that supplies power to the engine's self-powered system and main exciter after expanding the power generation capacity of the auxiliary excitation winding motor. The self-powered system includes two AC / DC starter generator controllers, two 270V high-voltage DC busbars, an energy storage device, a 28V low-voltage DC busbar, a multi-port bidirectional DC / DC converter, a multi-port bidirectional DC / AC inverter, an oil pump motor, and an electric actuator.

[0023] A generator with an all-electric engine self-powered system architecture has two sets of three-phase stator AC windings. The two sets of windings are isolated at the midpoint. One set of AC windings is responsible for powering airborne equipment other than the engine, i.e., external power supply, while the other set of windings is responsible for powering the engine's electrical equipment, i.e., self-power supply, so as to ensure that the self-powered system and the external power system are electrically isolated from each other and do not interfere with each other, thereby increasing the reliability of aircraft power supply. The generator has dual functions of starting and generating power. During the starting phase, it is powered by an energy storage device connected to dual 270V high-voltage DC busbars to control and drive the motor. The starting generator drives the aero-engine from a standstill to its ignition speed and assists the aero-engine in reaching its generating speed through the self-sustaining phase. During the generating phase, the system can provide a highly reliable self-powered engine that is unaffected by external factors while providing conventional external power supply. Specifically, the aero-engine drives the starting generator to rotate at high speed during the generating phase. The starting generator generates high-frequency, high-voltage AC power, which is rectified to 270V by the AC / DC starting generator controller to supply power to the load and to the energy storage device for storage. This creates a dual-circuit 270V high-voltage DC busbar and a 28V low-voltage DC busbar to supply power to the motor controller and electronic loads. When a single high-voltage DC busbar or both high-voltage DC busbars fail simultaneously, the redundancy power supply measures improve the reliability of the self-powered system.

[0024] The control strategy block diagram of the all-electric engine self-powered system architecture is as follows: Figure 2 As shown. During the startup phase, the energy storage device supplies power, starting the generator and driving it from standstill to generating speed. During the generation phase, when the self-powered system is supplying power normally and the load is operating normally, the 270V high-voltage DC busbar and the 28V low-voltage DC busbar supply power to the multi-port bidirectional DC / AC inverter and other electronic loads, enabling motor control and normal operation of the electronic loads.

[0025] The control strategy includes the following steps: Step S1: The self-powered system controls power generation, the storage device supplies power, and the generator starts to drive the engine to the power generation speed; Step S2: When the busbar is working normally, the load is running normally and energy is fed back to the power storage device. Step S3: When one of the 270V high-voltage DC busbars fails, the fault is disconnected, and the load is powered by the other 270V high-voltage DC busbar, realizing the dual redundancy power supply of the self-powered system; Step S4: When the AC / DC starter generator controller fails, neither of the two 270V busbars can supply power normally. The faulty AC / DC starter generator controller is disconnected, and the energy storage device supplies power to the faulty 270V high-voltage DC busbar through the multi-port bidirectional DC / DC converter to provide emergency power to the load in the engine system.

[0026] The energy storage device uses high-voltage batteries and supercapacitors, which can be used as a power supply for the AC / DC inverter during startup and as an emergency power supply for the load in the engine system, thereby improving the reliability of the self-powered system.

[0027] The energy feedback from the oil pump motor and electric actuator braking is transferred to the 270V high-voltage busbar via a multi-port bidirectional DC / AC inverter. The energy is then stored in an energy storage device or supplied to other loads via a power converter, achieving efficient energy utilization. The self-powered system needs to monitor the operating status of the two 270V high-voltage DC busbars in real time. When one of the 270V high-voltage DC busbars fails and cannot operate normally, the faulty part is disconnected, and power is supplied by the backup 270V high-voltage DC busbar. When both AC / DC starter generator controllers fail simultaneously, causing both 270V high-voltage DC busbars to be unable to supply power normally, both faulty controllers are disconnected from the power supply system, and the energy storage device supplies power to the 270V high-voltage DC busbars via a multi-port bidirectional DC / DC converter, providing emergency power to critical equipment in the engine system.

[0028] The all-electric engine self-powered system architecture can be used in existing typical high-voltage DC or AC / DC hybrid power supply systems for multi-electric aircraft. Among them, the self-powered system with dual redundancy and dual-circuit power supply of the present invention can effectively improve the reliability and safety of the airborne power supply system. At the same time, the self-powered system composed of a multi-port bidirectional power converter and an energy storage device can allow bidirectional energy flow, enabling the system to efficiently realize the conversion between power supply and electric functions and improve energy utilization efficiency.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions 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 self-powered all-electric engine system architecture, characterized in that, The self-powered system architecture includes two starter generators, a self-powered system, and an aircraft engine; the self-powered system is isolated from the external power system, achieving dual redundancy and dual-circuit power supply; The two starter generators are mechanically connected to the aircraft engine. The starter generators are dual-stator winding generators, including a dual-winding induction motor and a three-stage motor. The three-stage motor is a motor that supplies power to the engine's self-power supply system and the main exciter after the auxiliary excitation winding motor has been expanded in power generation capacity. The self-powered system includes two AC / DC starter generator controllers, two 270V high-voltage DC busbars, a 28V low-voltage DC busbar, an energy storage device, a multi-port bidirectional DC / DC converter, a multi-port bidirectional DC / AC inverter, an oil pump motor, and an electric actuator. External AC power is converted into 270V DC power by the two AC / DC starter generator controllers. The two 270V DC power lines are connected in parallel, and the energy storage device is connected to the parallel DC bus. The 270V DC power provides 28V DC power to the load through the multi-port bidirectional DC / DC converter, and powers the oil pump motor and electric actuator through the multi-port bidirectional DC / AC inverter.

2. The all-electric motor self-powered system architecture according to claim 1, characterized in that, The starter generator consists of two sets of three-phase windings with midpoint isolation. One set supplies power to airborne equipment other than the engine, i.e., external power supply, while the other set supplies power to the engine's electrical equipment, i.e., self-power supply. This ensures that the self-power supply system and the external power supply system are electrically isolated from each other and do not interfere with each other, thereby increasing the reliability of the aircraft's power supply.

3. The all-electric motor self-powered system architecture according to claim 1, characterized in that, During the engine start-up phase, the starter generator and AC / DC starter generator controller are powered by an energy storage device connected to dual 270V high-voltage DC busbars to control and drive the motor. The starter generator drives the engine from a standstill to the ignition speed and helps the engine reach the generator speed through the self-sustaining phase.

4. The all-electric motor self-powered system architecture according to claim 1, characterized in that, During the power generation phase, the aircraft engine drives the starter generator to rotate at high speed. The starter generator generates high-frequency, high-voltage AC power, which is rectified to 270V by the AC / DC starter generator controller to supply power to the load and to the energy storage device for storage.

5. The all-electric motor self-powered system architecture according to claim 1, characterized in that, The 270V high-voltage DC busbar and the 28V low-voltage DC busbar are electrically isolated by an isolated multi-port bidirectional DC / DC converter to prevent a fault in one circuit from affecting the other. The 270V high-voltage DC busbar is isolated from the oil pump and electric actuator by an isolated multi-port bidirectional DC / AC converter to ensure that the load operates normally when the 270V busbar fails.

6. The all-electric motor self-powered system architecture according to claim 1, characterized in that, The energy storage device uses high-voltage batteries and supercapacitors as power supplies during AC / DC inverter operation at startup and as emergency power supplies to the loads in the engine system, thereby improving the reliability of the self-powered system.

7. A control strategy for a self-powered all-electric motor system architecture, characterized in that, The control strategy is applied to a self-powered all-electric engine system architecture as described in any one of claims 1-6, and the control strategy includes the following control steps: Step S1: The self-powered system controls power generation, the storage device supplies power, and the generator starts to drive the engine to the power generation speed; Step S2: When the busbar is working normally, the load is running normally and energy is fed back to the power storage device. Step S3: When one of the 270V high-voltage DC busbars fails, the fault is disconnected, and the load is powered by the other 270V high-voltage DC busbar, realizing the dual redundancy power supply of the self-powered system; Step S4: When the AC / DC starter generator controller fails, neither of the two 270V busbars can supply power normally. The faulty AC / DC starter generator controller is disconnected, and the energy storage device supplies power to the faulty 270V high-voltage DC busbar through the multi-port bidirectional DC / DC converter to provide emergency power to the load in the engine system.

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