Series hybrid electric propulsion aircraft power supply system and power flow control method

Abstract

This invention discloses a power supply system and power flow control method for a series hybrid electric propulsion aircraft. In the power supply system, the generator's fully controlled rectifier is a three-phase fully controlled rectifier structure, which rectifies the AC power generated by the generator and outputs it to the DC bus, while also controlling the bus voltage. The energy storage battery is connected to the bus via an energy storage buck-boost converter, forming an energy storage subsystem, and its output / input power is controlled. Before connecting the fully controlled rectifier and the energy storage buck-boost converter to the bus, a circuit breaker is installed respectively. In case of a fault, the circuit breaker disconnects the corresponding device from the bus. The technical solution provided by this invention solves the problems of existing series hybrid aircraft, where the direct connection of the energy storage battery to the bus allows both the battery and generator to provide power to the electric motor, resulting in limited output voltage selection for the energy storage battery and the energy storage battery being in an uncontrolled state, thus reducing battery life.

Description

Technical Field

[0001] This application relates to, but is not limited to, the field of aviation electrical technology, and particularly to a series hybrid electric propulsion aircraft power supply system and power flow control method.

[0002] This achieves effective coordination between the generator and energy storage subsystems in the power supply system of an electric propulsion aircraft, thereby improving the reliability of the aircraft's power supply system. Background Technology

[0003] Electric aircraft technology is the future direction of the aviation industry, but due to the low energy density of batteries, pure electric aircraft are not yet suitable for long-distance flights. Therefore, hybrid electric aircraft are currently a more ideal choice.

[0004] like Figure 1 The diagram shown illustrates the power supply architecture of an existing series hybrid electric aircraft. As a type of hybrid-electric aircraft, this series hybrid electric aircraft features a simple structure and high reliability. Its power flow distribution is as follows: Figure 1 As shown, its working principle is as follows: the engine drives the high-speed generator to generate AC power, which is rectified and output to the DC bus. At the same time, the energy storage battery is connected to the bus, and the motor controller draws power from the DC bus to control the speed of the motor.

[0005] The existing power supply architecture of series hybrid aircraft connects the energy storage battery directly to the bus so that the battery and generator can jointly provide power to the electric motor. The charging and discharging of the energy storage battery relies entirely on the voltage regulation of the power generation system, which results in limited selection of the output voltage of the energy storage battery and the energy storage battery being in an uncontrolled state, thereby reducing the life of the energy storage battery. Summary of the Invention

[0006] The purpose of this invention is to solve the above-mentioned technical problems. This invention provides a series hybrid electric propulsion aircraft power supply system and power flow control method to address the problems of existing series hybrid aircraft, which suffer from limited output voltage selection of the energy storage battery and uncontrolled energy storage battery due to the direct connection of the energy storage battery to the bus to enable the battery and generator to jointly provide power to the motor, thereby reducing the lifespan of the energy storage battery.

[0007] The technical solution of the present invention: The present invention provides a series hybrid electric propulsion aircraft power supply system, including: a generator, a generator fully controlled rectifier connected to the generator, an energy storage buck-boost converter and an energy storage battery;

[0008] The generator fully controlled rectifier is configured as a three-phase fully controlled rectifier structure, which is used to rectify the AC power generated by the generator and output it to the DC bus, and to control the bus voltage by adjusting the generator output voltage.

[0009] The energy storage battery is connected to the bus via an energy storage buck-boost converter. The energy storage battery and the energy storage buck-boost converter form an energy storage subsystem, which is used to control the output / input power of the energy storage subsystem.

[0010] Before being connected to the bus, the generator fully controlled rectifier and the energy storage step-up / step-down converter are each equipped with a circuit breaker, which is used to disconnect the corresponding device from the bus in the event of a fault in the generator fully controlled rectifier or the energy storage step-up / step-down converter.

[0011] Optionally, in the series hybrid electric propulsion aircraft power supply system described above, the motor controller for controlling the operation of the electric motor is connected to the bus to draw power from the bus, and the method for controlling the output / input power of the energy storage subsystem includes:

[0012] When the power demand of the motor controller is greater than the power provided by the generator fully controlled rectifier, the energy storage buck-boost converter controls the output power of the energy storage subsystem according to the difference between the power consumption of the motor controller and the power generation of the fully controlled rectifier, so as to maintain the power supply stability of the series hybrid electric propulsion aircraft power supply system.

[0013] When the power demanded by the motor controller is less than the power provided by the fully controlled rectifier, the energy storage buck-boost converter selects either constant current charging or constant voltage charging mode based on the energy storage battery status and current power flow, thereby releasing a portion of the output power of the fully controlled rectifier.

[0014] Optionally, in the series hybrid electric propulsion aircraft power supply system described above, the method of controlling the output / input power of the energy storage subsystem further includes:

[0015] When the generator or the generator fully controlled rectifier fails, disconnect the circuit breaker connected to the generator fully controlled rectifier and supply power to the bus only through the energy storage battery.

[0016] When the energy storage subsystem fails, the circuit breaker connected to the energy storage step-up / step-down converter is disconnected, and the bus is powered only through the generator-controlled rectifier.

[0017] Optionally, in the series hybrid electric propulsion aircraft power supply system described above, the energy storage subsystem includes: an energy storage battery, an inductor L, a switch S1 and a switch S2, a diode D1 whose negative terminal is connected to the collector of switch S1 and whose positive terminal is connected to the transmitter of switch S1, and a diode D2 whose negative terminal is connected to the collector of switch S2 and whose positive terminal is connected to the transmitter of switch S2.

[0018] In this circuit, the emitter of switch S1 is connected to the collector of switch S2, one end of inductor L is connected to the positive electrode of the energy storage battery, and the other end of inductor L is connected to the emitter of switch S1 and the collector of switch S2 respectively. The collector of switch S1 is connected to the bus through a circuit breaker, and the negative electrode of the energy storage battery and the collector of switch S2 are connected to the bus.

[0019] Optionally, in the series hybrid electric propulsion aircraft power supply system described above, the discharge function of the energy storage subsystem is implemented as follows:

[0020] When the energy storage subsystem is discharging, switch S2 operates as a switch, while switch S1 is turned off. When switch S2 is turned on, the voltage of the energy storage battery is applied across the inductor L, and the energy storage battery charges the inductor L, which stores energy. When switch S2 is turned off, diode D1 is turned on, and the energy storage battery and inductor L supply energy to the bus through diode D1. Inductor L releases energy, thus realizing the discharge function of the energy storage subsystem.

[0021] Optionally, in the series hybrid electric propulsion aircraft power supply system described above, the charging function of the energy storage subsystem is implemented as follows:

[0022] When the energy storage subsystem is charging, switch S1 operates as a switch, while switch S2 is off. When switch S1 is on, the bus charges the energy storage battery through switch S1 and inductor L, and inductor L stores energy. When switch S1 is off, diode D2 is on, and the current in inductor L freewheels through diode D2, releasing energy and realizing the charging function of the energy storage subsystem.

[0023] Optionally, in the series hybrid electric propulsion aircraft power supply system described above, the generator fully controlled rectifier includes: a three-phase inverter connected to the generator, an outermost voltage regulation loop, and an i-type inverter that uses the output of the voltage regulation loop as a setpoint. q The current regulating loop and i with 0 as the setpoint d Current regulating ring;

[0024] Among them, the three-phase current sampling value i obtained through the three-phase inverter a i b i c The current i is obtained after Clark and Park operations. q i d , respectively as i q Current regulating loop and i d The control quantity of the current regulating loop; the target voltage u given by the host computer to the generator fully controlled rectifier device. *As an input parameter of the power supply system, it is compared with the voltage sampling value u on the bus, and the resulting voltage difference is used as the input parameter of the voltage regulation loop. The output of the voltage regulation loop is...

[0025] Output of voltage regulation loop For i q The setpoint of the current regulating loop is related to the current i. q The current difference is obtained by comparison as i q Input of the current regulating loop;

[0026] For i d The setpoint of the current regulating loop is related to the current i. d The current difference is obtained by comparison as i d Input of the current regulating loop;

[0027] i q Output of the current regulating loop and i d Output of the current regulating loop Obtained by inverse Park transform respectively The SVPWM algorithm outputs the duty cycle and conduction time of PWM1-PWM3 through channels A and B, thereby achieving regulation and control of the generator output voltage.

[0028] This invention also provides a power flow control method for a series hybrid electric propulsion aircraft power supply system, the power flow control method executed by the series hybrid electric propulsion aircraft power supply system as described in any of the above claims, comprising:

[0029] Step 1: The generator fully controlled rectifier rectifies the AC power generated by the generator and outputs it to the DC bus, and controls the bus voltage by adjusting the generator output voltage.

[0030] Step 2: The energy storage subsystem controls its output power or input power by comparing the power demanded by the motor controller with the power provided by the generator fully controlled rectifier.

[0031] Optionally, in the power flow control method for the series hybrid electric propulsion aircraft power supply system described above, the series hybrid electric propulsion aircraft power supply system includes a fully controlled generator rectifier, and the regulation and control method for the generator output voltage in step 1 includes:

[0032] S11, based on the target voltage u given by the host computer * As an input parameter of the power supply system, it is compared with the voltage sampling value u on the bus, and the resulting voltage difference is used as the input parameter of the voltage regulation loop and output.

[0033] S12 will output the voltage regulation loop. As i q The setpoint of the current regulating loop is related to the current i. q The current difference is obtained by comparison as i q The input of the current regulating loop; where the current i q The three-phase current sampling value i obtained through the three-phase inverter a i b i c The result obtained after Clark and Park operations;

[0034] S13, will As i d The setpoint of the current regulating loop is related to the current i. d The current difference is obtained by comparison as i d The input of the current regulating loop; where the current i d The three-phase current sampling value i obtained through the three-phase inverter a i b i c The result obtained after Clark and Park operations;

[0035] S14, i q Output of the current regulating loop and i d Output of the current regulating loop Obtained by inverse Park transform respectively after, The SVPWM algorithm outputs the duty cycle and conduction time of PWM1-PWM3 through channels A and B, thereby achieving regulation and control of the generator output voltage.

[0036] Optionally, in the power flow control method for a series hybrid electric propulsion aircraft power supply system as described above, step 2 includes:

[0037] S21, determine the power required by the motor controller and the power provided by the generator fully controlled rectifier;

[0038] S22, When the power demand of the motor controller is greater than the power provided by the generator fully controlled rectifier, the energy storage step-up converter controls the output power of the energy storage subsystem according to the difference between the power consumption of the motor controller and the power generation of the fully controlled rectifier, so as to maintain the power supply stability of the power supply system.

[0039] S23, when the power demanded by the motor controller is less than the power provided by the fully controlled rectifier, the energy storage buck-boost converter selects the battery charging mode according to the energy storage battery status and the current power flow, thereby releasing a portion of the output power of the fully controlled rectifier.

[0040] S24, real-time judgment of the fault status of generator, generator full control rectifier device and energy storage subsystem;

[0041] S25, when the generator or generator fully controlled rectifier fails, disconnect the circuit breaker connected to the generator fully controlled rectifier and supply power to the bus only through the energy storage battery;

[0042] S26, When the energy storage subsystem fails, disconnect the circuit breaker connected to the energy storage step-up / step-down converter and supply power to the bus only through the generator fully controlled rectifier.

[0043] The beneficial effects of this invention: The series-type hybrid electric propulsion aircraft power supply system and power flow control method provided in this embodiment of the invention include a generator fully controlled rectifier device configured as a three-phase fully controlled rectifier structure, which rectifies the AC power generated by the generator and outputs it to the DC bus, using the bus voltage as the control target; the energy storage battery is connected to the bus through an energy storage buck-boost converter, using the output / input power of the energy storage subsystem as the control target; a circuit breaker is installed before the generator fully controlled rectifier device and the energy storage buck-boost converter are connected to the bus, so as to disconnect the device from the bus in case of a fault. The series-type hybrid electric propulsion aircraft power supply system provided in this embodiment of the invention has a simple structure and can achieve decoupling control of the bus voltage and the power (current) of the energy storage subsystem, providing a new method and idea for the design of series-type hybrid electric propulsion aircraft power supply systems; in its control method, due to the decoupling control of the bus voltage and the power (current) of the energy storage subsystem, and the effective cooperation between the fully controlled rectifier device and the energy storage subsystem, the reliability of the hybrid aircraft power supply system is improved. The technical solution provided in this embodiment of the invention has the following specific beneficial effects:

[0044] 1) The generator fully controlled rectifier device controls the bus voltage, and the energy storage step-up / step-down converter device controls the input power or output function of the energy storage subsystem. This realizes the independent control of the two devices within a system and decouples the voltage of the generator system (including the generator and the fully controlled rectifier device) from the power (current) of the energy storage subsystem.

[0045] 2) The energy storage buck-boost converter can realize constant voltage charging and constant current charging of energy storage batteries, and the discharge of energy storage batteries is instantaneously controllable, which improves the life of energy storage batteries and reduces the risk of fire.

[0046] 3) Circuit breakers can isolate faulty devices from the power system, improving system reliability;

[0047] 4) Both the fully controlled rectifier system and the energy storage subsystem can independently supply power to the motor controller and the motor, improving system reliability. Attached Figure Description

[0048] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of the present invention and do not constitute a limitation on the technical solutions of the present invention.

[0049] Figure 1 A schematic diagram of the power supply architecture of an existing series hybrid electric aircraft;

[0050] Figure 2 This is a schematic diagram of the system architecture of a series hybrid electric propulsion aircraft power supply system provided in an embodiment of the present invention;

[0051] Figure 3 This is a schematic diagram of the energy storage subsystem in a series hybrid electric propulsion aircraft power supply system provided in an embodiment of the present invention;

[0052] Figure 4 This is a schematic diagram of the generator fully controlled rectifier device in the series hybrid electric propulsion aircraft power supply system provided in an embodiment of the present invention;

[0053] Figure 5 A cascaded simulation diagram of a series hybrid electric propulsion aircraft power supply system provided for an embodiment of the present invention;

[0054] Figure 6 for Figure 5 The diagram illustrates the balance between the input power of the motor controller, the output power of the generator, and the output / input power of the energy storage subsystem in the illustrated embodiment. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

[0056] As explained in the background section, the existing power supply architecture of series hybrid aircraft achieves power supply to the electric motor by directly connecting the energy storage battery to the bus, with the battery and generator working together. The charging and discharging of the energy storage battery relies entirely on voltage regulation by the power generation system, which has the following drawbacks:

[0057] 1) The output voltage of the energy storage battery is limited and must be close to the bus voltage;

[0058] 2) When the energy storage battery is in an uncontrolled state, its charging and discharging processes are regulated by the bus voltage. When the bus voltage fluctuates, the charging and discharging cycles of the energy storage battery occur, resulting in reduced efficiency.

[0059] 3) When the bus voltage is not regulated in time and peaks or troughs occur, the energy storage battery will be under high current charging or high current discharging, which can easily cause fire.

[0060] 4) Uncontrolled charging and discharging of energy storage batteries will reduce battery life.

[0061] To address the problems existing in the power supply architecture of current series hybrid-electric aircraft, a reliable power supply system is needed to reduce the risk of battery fires, improve battery life, and enhance system reliability. Based on this requirement, this invention provides a power supply system and power flow control method for a series hybrid electric propulsion aircraft.

[0062] The present invention provides the following specific embodiments, which can be combined with each other. For the same or similar concepts or processes, they may not be described again in some embodiments.

[0063] Figure 2 This is a schematic diagram of the system architecture of a series hybrid electric propulsion aircraft power supply system provided in an embodiment of the present invention. Figure 2 As shown, the structure of the series hybrid electric propulsion aircraft power supply system provided in this embodiment of the invention may include: a generator fully controlled rectifier, an energy storage buck-boost converter, and an energy storage battery.

[0064] First, the generator fully controlled rectifier in this embodiment of the invention is configured as a three-phase fully controlled rectifier structure, which is used to output the AC power generated by the generator to the DC bus after rectification. The control target of the generator fully controlled rectifier is the bus voltage. In practical applications, the bus voltage is controlled by regulating the generator output voltage.

[0065] Secondly, in this embodiment of the invention, the energy storage battery is connected to the bus via an energy storage buck-boost converter. The energy storage battery and the energy storage buck-boost converter together form an energy storage subsystem. The control target is the output / input power of the energy storage subsystem, that is, controlling the output / input current.

[0066] Furthermore, in this embodiment of the invention, a circuit breaker is installed before the generator fully controlled rectifier and the energy storage step-up / step-down converter are connected to the bus, so as to disconnect the device from the bus in case of a fault.

[0067] In the power supply system provided by this embodiment of the invention, the motor controller connected to the bus draws power from the bus to control the operation of the motor.

[0068] Based on the structure of the series hybrid electric propulsion aircraft power supply system provided in this embodiment of the invention, the power flow control of the power supply system is implemented as follows:

[0069] In normal operating mode, the generator fully controlled rectifier aims to keep the bus voltage constant. When the power demand of the motor controller is greater than the power that the generator fully controlled rectifier can provide, the energy storage buck-boost converter controls the output power of the energy storage subsystem based on the difference between the power consumption of the motor controller and the power generation of the fully controlled rectifier, in order to maintain the power supply stability of the series hybrid electric propulsion aircraft power supply system. When the power demand of the motor controller is less than the power that the fully controlled rectifier can provide, the energy storage buck-boost converter selects either the battery charging mode - constant current charging or the battery charging mode - constant voltage charging based on the state of the energy storage battery and the current power flow, that is, releasing a portion of the output power of the fully controlled rectifier. At this time, it is the control of the input power of the energy storage subsystem.

[0070] In normal operating mode, if the generator or generator fully controlled rectifier fails, the circuit breaker connected to the generator fully controlled rectifier is disconnected, and the bus is powered only through the energy storage battery; if the energy storage subsystem fails, the circuit breaker connected to the energy storage step-up / step-down converter is disconnected, and the bus is powered only through the generator fully controlled rectifier.

[0071] The series hybrid electric propulsion aircraft power supply system provided in this embodiment of the invention has a simple structure and can achieve decoupled control of the bus voltage and the power (current) of the energy storage subsystem of the series hybrid electric propulsion aircraft power supply system, providing a new method and idea for the design of series hybrid electric propulsion aircraft power supply systems.

[0072] like Figure 3 The diagram shown is a structural schematic of the energy storage subsystem in a series hybrid electric propulsion aircraft power supply system provided in an embodiment of the present invention. In one implementation of the present invention, the energy storage subsystem can achieve bidirectional flow of electrical energy from 540V to 270V. Its input / output power is determined by the energy storage buck-boost converter based on a comprehensive judgment of the flight status, generator output power, and load power to achieve bus voltage stability.

[0073] like Figure 3 The energy storage subsystem shown includes: an energy storage battery, an inductor L, switching transistors S1 and S2, a diode D1 whose negative terminal is connected to the collector of switching transistor S1 and whose positive terminal is connected to the transmitter of switching transistor S1, and a diode D2 whose negative terminal is connected to the collector of switching transistor S2 and whose positive terminal is connected to the transmitter of switching transistor S2.

[0074] Figure 3 In the energy storage subsystem shown, the emitter of switch S1 is connected to the collector of switch S2, one end of inductor L is connected to the positive electrode of the energy storage battery, and the other end of inductor L is connected to the emitter of switch S1 and the collector of switch S2 respectively. The collector of switch S1 is connected to the bus through a circuit breaker, and the negative electrode of the energy storage battery and the collector of switch S2 are connected to the bus.

[0075] In this implementation method, based on Figure 3 The structure of the energy storage subsystem shown is as follows: During discharge operation, switch S2 operates as a switch, while switch S1 is off, making the circuit a Boost converter. When switch S2 is on, the voltage of the energy storage battery is applied across inductor L, causing the current in inductor L to increase linearly. The energy storage battery charges inductor L, which stores energy as magnetic field energy. When switch S2 is off, diode D1 conducts, and the energy storage battery and inductor L supply energy to the output bus through diode D1. Inductor L releases energy, thus realizing the discharge function of the energy storage subsystem.

[0076] When the energy storage subsystem is charging, switch S1 operates as a switch, while switch S2 is off, making the circuit a Buck converter. When switch S1 is on, the output bus U2 charges the energy storage battery through switch S1 and inductor L. The current in inductor L increases linearly, storing energy in the inductor as magnetic field energy. When switch S1 is off, diode D2 conducts, allowing the current in inductor L to freewheel through diode D2, resulting in a linear decrease in the current in inductor L. This releases energy, thus enabling the energy storage subsystem to charge.

[0077] It should be noted that, in the embodiments of the present invention, when the energy storage subsystem implements the charging function, it will select constant current charging or constant voltage charging according to the current power of the energy storage battery. When the battery power is less than 80% of the total capacity, constant current charging is selected to achieve the purpose of fast charging. When the battery power is greater than 80% of the total capacity, constant voltage charging is selected to reduce the charging current. When the battery power is greater than 95% of the total capacity, charging is not performed.

[0078] like Figure 4 The diagram shown is a schematic representation of the fully controlled rectifier device for a generator in a series hybrid electric propulsion aircraft power supply system according to an embodiment of the present invention. In one implementation of this invention, the fully controlled rectifier device includes: a three-phase inverter connected to the generator, an outermost voltage regulation loop, and an i-type inverter that uses the output of the voltage regulation loop as a given value. q The current regulating loop and i with 0 as the setpoint d Current regulating ring.

[0079] In this implementation, the three-phase current sampling value i is obtained through the three-phase inverter. a i b i c The current i is obtained after Clark and Park operations. q i d , respectively as i q Current regulating loop and i dControl quantities of the current regulating loop;

[0080] Voltage regulation loop: The generator fully controlled rectifier unit uses the target voltage u given by the host computer. * As an input parameter of the power supply system, it is compared with the voltage sampling value u on the bus to obtain the voltage difference, and this voltage difference is used as the input parameter of the voltage regulation loop; the output of the voltage regulator in the voltage regulation loop is... Furthermore, the voltage regulator can use proportional-integral (PI) control for voltage control.

[0081] i q Current regulation loop: Output of voltage regulation loop For i q The setpoint of the current regulating loop is compared with the three-phase current sampling value i. a i b i c The current i calculated by Clark and Park q The current difference is obtained by comparison, and the current difference is used as i. q Input to the current regulating loop.

[0082] i d Current regulating ring: For i d The setpoint of the current regulating loop is compared with the three-phase current sampling value i. a i b i c The current i calculated by Clark and Park d The current difference is obtained by comparison, and the current difference is used as i. d Input to the current regulating loop.

[0083] i q Output of the current regulating loop and i d Output of the current regulating loop Obtained by inverse Park transform respectively The SVPWM algorithm outputs the duty cycle and conduction time of PWM1-PWM3 through channels A and B, thereby achieving regulation and control of the generator output voltage.

[0084] It should be noted that i q Current regulating loop and i d The current regulating loop can also be controlled and regulated using a proportional-integral (PI) method; in addition, the position information obtained by detecting the rotor position of the generator is transmitted to Park as a computational quantity.

[0085] Based on the series hybrid electric propulsion aircraft power supply system provided in the above embodiments of the present invention, the present invention also provides a power flow control method for the series hybrid electric propulsion aircraft power supply system. The execution steps of the power flow control method may include:

[0086] Step 1: The generator fully controlled rectifier rectifies the AC power generated by the generator and outputs it to the DC bus, and controls the bus voltage by adjusting the generator output voltage.

[0087] Step 2: The energy storage subsystem controls its output power or input power by comparing the power demanded by the motor controller with the power provided by the generator fully controlled rectifier.

[0088] See Figure 4 The control principle of the generator fully controlled rectifier device shown, and the implementation method of adjusting the generator output voltage in step 1, may include:

[0089] S11, based on the target voltage u given by the host computer * As an input parameter of the power supply system, it is compared with the voltage sampling value u on the bus, and the resulting voltage difference is used as the input parameter of the voltage regulation loop and output.

[0090] S12 will output the voltage regulation loop. As i q The setpoint of the current regulating loop is related to the current i. q The current difference is obtained by comparison as i q The input of the current regulating loop; where the current i q The three-phase current sampling value i obtained through the three-phase inverter a i b i c The result obtained after Clark and Park operations;

[0091] S13, will As i d The setpoint of the current regulating loop is related to the current i. d The current difference is obtained by comparison as i d The input of the current regulating loop; where the current i d The three-phase current sampling value i obtained through the three-phase inverter a i b i c The result obtained after Clark and Park operations;

[0092] S14, i q Output of the current regulating loop and i d Output of the current regulating loop Obtained by inverse Park transform respectively after, The SVPWM algorithm outputs the duty cycle and conduction time of PWM1-PWM3 through channels A and B, thereby achieving regulation and control of the generator output voltage.

[0093] In this embodiment of the invention, the method for implementing output power or input power control of the energy storage subsystem includes:

[0094] S21, determine the power required by the motor controller and the power provided by the generator fully controlled rectifier;

[0095] S22, When the power demand of the motor controller is greater than the power provided by the generator fully controlled rectifier, the energy storage step-up converter controls the output power of the energy storage subsystem according to the difference between the power consumption of the motor controller and the power generation of the fully controlled rectifier, so as to maintain the power supply stability of the power supply system.

[0096] S23, when the power demanded by the motor controller is less than the power provided by the fully controlled rectifier, the energy storage buck-boost converter selects the battery charging mode according to the energy storage battery status and the current power flow, so as to release a part of the output power of the fully controlled rectifier.

[0097] S24, real-time judgment of the fault status of generator, generator full control rectifier device and energy storage subsystem;

[0098] S25, when the generator or generator fully controlled rectifier fails, disconnect the circuit breaker connected to the generator fully controlled rectifier and supply power to the bus only through the energy storage battery;

[0099] S26, When the energy storage subsystem fails, disconnect the circuit breaker connected to the energy storage step-up / step-down converter and supply power to the bus only through the generator fully controlled rectifier.

[0100] This invention provides a series-type hybrid electric propulsion aircraft power supply system and power flow control method. In this system, the generator's fully controlled rectifier is configured as a three-phase fully controlled rectifier structure, rectifying the AC power generated by the generator and outputting it to the DC bus, with the bus voltage as the control target. The energy storage battery is connected to the bus via an energy storage buck-boost converter, with the output / input power of the energy storage subsystem as the control target. A circuit breaker is installed before each of the generator's fully controlled rectifier and the energy storage buck-boost converter is connected to the bus to disconnect the devices from the bus in case of a fault. The series-type hybrid electric propulsion aircraft power supply system provided by this invention has a simple structure and can achieve decoupling control of the bus voltage and the power (current) of the energy storage subsystem, providing a new method and approach for the design of series-type hybrid electric propulsion aircraft power supply systems. Its control method improves the reliability of the hybrid aircraft power supply system by achieving decoupling control of the bus voltage and the power (current) of the energy storage subsystem, and by achieving effective cooperation between the fully controlled rectifier and the energy storage subsystem. The technical solution provided by this invention has the following specific beneficial effects:

[0101] 1) The generator fully controlled rectifier device controls the bus voltage, and the energy storage step-up / step-down converter device controls the input power or output function of the energy storage subsystem. This realizes the independent control of the two devices within a system and decouples the voltage of the generator system (including the generator and the fully controlled rectifier device) from the power (current) of the energy storage subsystem.

[0102] 2) The energy storage buck-boost converter can realize constant voltage charging and constant current charging of energy storage batteries, and the discharge of energy storage batteries is instantaneously controllable, which improves the life of energy storage batteries and reduces the risk of fire.

[0103] 3) Circuit breakers can isolate faulty devices from the power system, improving system reliability;

[0104] 4) Both the fully controlled rectifier system and the energy storage subsystem can independently supply power to the motor controller and the motor, improving system reliability.

[0105] The following is a specific embodiment illustrating the implementation of the series hybrid electric propulsion aircraft power supply system and power flow control method provided by the present invention.

[0106] Figure 5 This is a cascaded simulation diagram of a series hybrid electric propulsion aircraft power supply system provided by an embodiment of the present invention. Figure 6 for Figure 5 The diagram illustrates the balance between the input power of the motor controller, the output power of the generator (i.e., the output power of the fully controlled rectifier), and the output / input power of the energy storage subsystem in the embodiment shown.

[0107] Figure 6 The process is divided into four stages. In the first stage, the input power of the electric motor equals the output power of the generator; at this time, the energy storage subsystem neither outputs nor inputs power. In the second stage, the input power of the electric motor is greater than the output power of the generator; at this time, a certain control strategy is used to control the output power of the energy storage subsystem to maintain power balance among the three. In the third stage, the input power of the electric motor equals the output power of the generator; at this time, the energy storage subsystem neither outputs nor inputs power. In the fourth stage, the input power of the electric motor is less than the output power of the generator; at this time, a certain control strategy is used to control the input power of the energy storage subsystem for charging. The series-connected hybrid electric propulsion aircraft power supply system provided in this embodiment can automatically switch between multiple stages and operate reliably and stably.

[0108] The series hybrid electric propulsion aircraft power supply system provided in this invention has been applied to a series hybrid electric propulsion aircraft, and its battery life and reliability have been greatly improved, thus enhancing the overall performance of the power supply system.

[0109] While the embodiments disclosed in this invention are as described above, they are merely illustrative of the embodiments to facilitate understanding of the invention and are not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in the form and details of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A series hybrid electric propulsion aircraft power supply system, characterized in that, include: A generator, a generator-controlled rectifier connected to the generator, an energy storage step-up / step-down converter, and an energy storage battery; The generator full-control rectifier device is arranged in a three-phase full-control rectifier structure, and comprises a three-phase inverter connected with the generator, a voltage regulation loop located in the outermost layer, and an i q current regulation loop taking 0 as a given value d current regulation loop; the generator full-control rectifier device is used for rectifying alternating current generated by the generator and outputting the rectified alternating current to a direct current bus, and controlling the bus voltage by regulating the output voltage of the generator; The energy storage battery is connected to the bus via an energy storage buck-boost converter. The energy storage battery and the energy storage buck-boost converter form an energy storage subsystem for controlling the output / input power of the energy storage subsystem. The energy storage subsystem includes: an energy storage battery, an inductor L, a switching transistor S1 and a switching transistor S2, a diode D1 whose negative terminal is connected to the base electrode of the switching transistor S1 and whose positive terminal is connected to the emitter of the switching transistor S1, and a diode D2 whose negative terminal is connected to the base electrode of the switching transistor S2 and whose positive terminal is connected to the emitter of the switching transistor S2. The emitter of the switching transistor S1 is connected to the base electrode of the switching transistor S2. One end of the inductor L is connected to the positive electrode of the energy storage battery, and the other end of the inductor L is connected to the emitter of the switching transistor S1 and the base electrode of the switching transistor S2. The base electrode of the switching transistor S1 is connected to the bus via a circuit breaker, and the negative electrode of the energy storage battery and the emitter of the switching transistor S2 are connected to the bus. Before the generator fully controlled rectifier and the energy storage step-up / step-down converter are connected to the bus, a circuit breaker is installed to disconnect the corresponding device from the bus in the event of a fault in the generator fully controlled rectifier or the energy storage step-up / step-down converter. The aforementioned series-type hybrid electric propulsion aircraft power supply system includes a motor controller for controlling the operation of the electric motor connected to the busbar for drawing power from the busbar. The methods for controlling the output / input power of the energy storage subsystem include: When the power demand of the motor controller is greater than the power provided by the generator fully controlled rectifier, the energy storage buck-boost converter controls the output power of the energy storage subsystem according to the difference between the power consumption of the motor controller and the power generation of the fully controlled rectifier, so as to maintain the power supply stability of the series hybrid electric propulsion aircraft power supply system. When the power demanded by the motor controller is less than the power provided by the fully controlled rectifier, the energy storage buck-boost converter selects either constant current charging or constant voltage charging mode based on the energy storage battery status and current power flow, thereby releasing a portion of the output power of the fully controlled rectifier.

2. The series hybrid electric propulsion airplane power supply system of claim 1, wherein, The method of controlling the output / input power of the energy storage subsystem also includes: When the generator or the generator fully controlled rectifier fails, disconnect the circuit breaker connected to the generator fully controlled rectifier and supply power to the bus only through the energy storage battery. When the energy storage subsystem fails, the circuit breaker connected to the energy storage step-up / step-down converter is disconnected, and the bus is powered only through the generator-controlled rectifier.

3. The series hybrid electric propulsion aircraft power supply system according to claim 1, characterized in that, The discharge function of the energy storage subsystem is implemented as follows: When the energy storage subsystem is discharging, switch S2 operates as a switch, while switch S1 is turned off. When switch S2 is turned on, the voltage of the energy storage battery is applied across the inductor L, and the energy storage battery charges the inductor L, which stores energy. When switch S2 is turned off, diode D1 is turned on, and the energy storage battery and inductor L supply energy to the bus through diode D1. Inductor L releases energy, thus realizing the discharge function of the energy storage subsystem.

4. The series hybrid electric propulsion aircraft power supply system according to claim 1, characterized in that, The charging function of the energy storage subsystem is implemented as follows: When the energy storage subsystem is charging, switch S1 operates as a switch, while switch S2 is off. When switch S1 is on, the bus charges the energy storage battery through switch S1 and inductor L, and inductor L stores energy. When switch S1 is off, diode D2 is on, and the current in inductor L freewheels through diode D2, releasing energy and realizing the charging function of the energy storage subsystem.

5. The series hybrid electric propulsion aircraft power supply system according to any one of claims 1 to 4, characterized in that, In the generator fully controlled rectifier device The three-phase current sampling value i obtained through the three-phase inverter a i b i c The current i is obtained after Clark and Park operations. q i d , respectively as i q Current regulating loop and i d The control quantity of the current regulating loop; the target voltage u given by the host computer to the generator fully controlled rectifier device. * As an input parameter of the power supply system, it is compared with the voltage sampling value u on the bus, and the resulting voltage difference is used as the input parameter of the voltage regulation loop. The output of the voltage regulation loop is... ; Output of voltage regulation loop For i q The setpoint of the current regulating loop is related to the current i. q The current difference is obtained by comparison as i q Input of the current regulating loop; For i d The setpoint of the current regulating loop is related to the current i. d The current difference is obtained by comparison as i d Input of the current regulating loop; i q Output of the current regulating loop and i d Output of the current regulating loop Obtained by inverse Park transform respectively , The SVPWM algorithm outputs the duty cycle and conduction time of PWM1-PWM3 through channels A and B, thereby achieving regulation and control of the generator output voltage.

6. A power flow control method for a series hybrid electric propulsion aircraft power supply system, characterized in that, The power flow control method executed by the series hybrid electric propulsion aircraft power supply system as described in any one of claims 1 to 5 includes: Step 1: The generator fully controlled rectifier rectifies the AC power generated by the generator and outputs it to the DC bus, and controls the bus voltage by adjusting the generator output voltage. Step 2: The energy storage subsystem controls its output power or input power by comparing the power demanded by the motor controller with the power provided by the generator fully controlled rectifier.

7. The power flow control method for a series hybrid electric propulsion aircraft power supply system according to claim 6, characterized in that, The series hybrid electric propulsion aircraft power supply system includes the generator fully controlled rectifier as described in claim 5, and the method for regulating and controlling the generator output voltage in step 1 includes: S11, based on the target voltage u given by the host computer * As an input parameter of the power supply system, it is compared with the voltage sampling value u on the bus, and the resulting voltage difference is used as the input parameter of the voltage regulation loop and output. ; S12 will output the voltage regulation loop. As i q The setpoint of the current regulating loop is related to the current i. q The current difference is obtained by comparison as i q The input of the current regulating loop; where the current i q The three-phase current sampling value i obtained through the three-phase inverter a i b i c The result obtained after Clark and Park operations; S13, As i d The setpoint of the current regulating loop is related to the current i. d The current difference is obtained by comparison as i d Input of the current regulating loop; wherein the current i d is a three-phase current sample value i a , i b , i c obtained after Clark, Park operation; S14, i q Output of the current regulating loop and i d Output of the current regulating loop Obtained by inverse Park transform respectively ,after, The SVPWM algorithm outputs the duty cycle and conduction time of PWM1-PWM3 through channels A and B, thereby achieving regulation and control of the generator output voltage.

8. The power flow control method for a series hybrid electric propulsion aircraft power supply system according to claim 6, characterized in that, Step 2 includes: S21, determine the power required by the motor controller and the power provided by the generator fully controlled rectifier; S22, When the power demand of the motor controller is greater than the power provided by the generator fully controlled rectifier, the energy storage step-up converter controls the output power of the energy storage subsystem according to the difference between the power consumption of the motor controller and the power generation of the fully controlled rectifier, so as to maintain the power supply stability of the power supply system. S23, when the power demanded by the motor controller is less than the power provided by the fully controlled rectifier, the energy storage buck-boost converter selects the battery charging mode according to the energy storage battery status and the current power flow, thereby releasing a portion of the output power of the fully controlled rectifier. S24, real-time judgment of the fault status of generator, generator full control rectifier device and energy storage subsystem; S25, when the generator or generator fully controlled rectifier fails, disconnect the circuit breaker connected to the generator fully controlled rectifier and supply power to the bus only through the energy storage battery; S26, When the energy storage subsystem fails, disconnect the circuit breaker connected to the energy storage step-up / step-down converter and supply power to the bus only through the generator fully controlled rectifier.

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