Dual chemical propulsion system for electric vertical takeoff and landing aircraft

Abstract

A system in an electric vertical takeoff and landing (eVTOL) aircraft includes two or more subsystems, each including an energy storage system (ESS). Each ESS is coupled to one or more motors actuating one or more rotors of the eVTOL aircraft and includes one or more energy subpacks and one or more power subpacks. The one or more power subpacks supply more power than the one or more energy subpacks, and the one or more energy subpacks supply stable power for a longer duration than the one or more power subpacks. The system further includes one or more inter-subsystem switches to electrically isolate or connect adjacent ones of the two or more subsystems.

Description

Technical Field

[0001] This invention relates to a dual chemical propulsion system for electric vertical takeoff and landing (eVTOL) aircraft. Background Technology

[0002] eVTOL aircraft use electric power for vertical takeoff, hovering or maneuvering, and vertical landing. The propulsion system of an eVTOL includes electric motors to operate rotors arranged around the eVTOL and propelling its motion. The propulsion system must meet energy requirements while minimizing mass. Therefore, a dual-chemical propulsion system is desired for eVTOL aircraft. Summary of the Invention

[0003] In one exemplary embodiment, a system in an electric vertical takeoff and landing (eVTOL) aircraft includes two or more subsystems. Each subsystem includes an energy storage system (ESS). Each ESS is coupled to one or more motors actuating one or more rotors of the eVTOL aircraft and includes one or more energy subpacks and one or more power subpacks. The one or more power subpacks supply more power than the one or more energy subpacks, and the one or more energy subpacks supply stable power for a longer duration than the one or more power subpacks. The system also includes one or more inter-subsystem switches to electrically isolate or connect adjacent subsystems among the two or more subsystems.

[0004] In addition to one or more features described herein, each ESS is connected to one or more motors via a switch.

[0005] In addition to one or more features described herein, the system also includes a controller to control the switches of each ESS and the switches between one or more subsystems.

[0006] In addition to one or more features described herein, the controller controls the switch of each ESS to close during normal operation to connect the ESS to one or more motors, and the controller also disconnects the fault control switch in the ESS to isolate one or more motors from the ESS.

[0007] In addition to one or more features described herein, the controller controls one of one or more inter-subsystem switches between adjacent subsystems in two or more subsystems to close based on the detection of a fault in the ESS of one of the adjacent subsystems in the two or more subsystems, in order to provide redundancy to the ESS of the other of the adjacent subsystems in the two or more subsystems.

[0008] In addition to one or more features described herein, each ESS also includes a bidirectional DC-DC converter to boost the voltage output from one or more power sub-packets or to connect one or more energy sub-packets to one or more power sub-packets for charging one or more power sub-packets.

[0009] In addition to one or more features described herein, for each ESS, one or more energy sub-packets and one or more power sub-packets power one or more motors during takeoff of the eVTOL aircraft.

[0010] In addition to one or more features described here, for each ESS, during the cruise of an eVTOL aircraft, only one or more energy sub-packets power one or more motors.

[0011] In addition to one or more features described herein, during the cruise of an eVTOL aircraft, one or more energy sub-packets of each ESS recharge one or more power sub-packets of the ESS.

[0012] In addition to one or more features described herein, for each ESS, one or more energy sub-packets and one or more power sub-packets power one or more motors during the landing of an eVTOL aircraft.

[0013] In another exemplary embodiment, a method of assembling a system in an electric vertical takeoff and landing (eVTOL) aircraft includes arranging two or more subsystems. Each subsystem includes an energy storage system (ESS). The method also includes coupling each ESS to one or more motors actuating one or more rotors of the eVTOL aircraft; arranging one or more energy subpacks in each ESS; and arranging one or more power subpacks in each ESS. One or more power subpacks supply more power than one or more energy subpacks, and one or more energy subpacks supply stable power for a longer duration than one or more power subpacks. Switches between one or more subsystems are controlled to electrically isolate or connect adjacent subsystems in the two or more subsystems.

[0014] In addition to one or more features described herein, each ESS is connected to one or more motors via a switch.

[0015] In addition to one or more features described herein, the method also includes configuring a controller to control the switches of each ESS and the switches between one or more subsystems.

[0016] In addition to one or more features described herein, the configuration controller includes controlling the switch of each ESS to close during normal operation to connect the ESS to one or more motors, and disengaging based on a fault control switch in the ESS to isolate one or more motors from the ESS.

[0017] In addition to one or more features described herein, the configuration controller includes the controller controlling one of one or more inter-subsystem switches between two or more adjacent subsystems to close based on the detection of a fault in an ESS in one of the two or more adjacent subsystems, in order to provide redundancy to an ESS in another of the two or more adjacent subsystems.

[0018] In addition to one or more features described herein, the method also includes arranging a bidirectional DC-DC converter in each ESS to boost the voltage output of one or more power sub-packets or to connect one or more energy sub-packets to one or more power sub-packets for charging one or more power sub-packets.

[0019] In addition to one or more features described herein, the method also includes configuring one or more energy sub-packets and one or more power sub-packets for each ESS to power one or more motors during takeoff of the eVTOL aircraft.

[0020] In addition to one or more features described herein, the method also includes configuring one or more energy sub-packets and one or more power sub-packets for each ESS, such that only one or more energy sub-packets power one or more motors during the cruise of the eVTOL aircraft.

[0021] In addition to one or more features described herein, the method also includes configuring one or more energy sub-packets of each ESS to recharge one or more power sub-packets of the ESS during cruise of the eVTOL aircraft.

[0022] In addition to one or more features described herein, the method also includes configuring one or more energy sub-packets and one or more power sub-packets for each ESS to power one or more motors during landing of the eVTOL aircraft.

[0023] The above-described features and advantages, as well as other features and advantages, of this disclosure will become apparent from the following detailed description when taken in conjunction with the accompanying drawings. Attached Figure Description

[0024] Other features, advantages, and details appear only by way of example in the following detailed description, which refers to the accompanying drawings, wherein:

[0025] Figure 1It is a block diagram of an electric vertical takeoff and landing (eVTOL) aircraft with a dual chemical propulsion system according to one or more embodiments;

[0026] Figure 2 This is a schematic diagram of a dual chemical propulsion system for an eVTOL aircraft according to one or more embodiments;

[0027] Figure 3 It is a graph representing the power provided by the dual-chemical ESS according to an exemplary embodiment;

[0028] Figure 4 It is a graph representing the state of charge (SoC) of the energy sub-packet and power sub-packet of an exemplary dual-chemical ESS according to an exemplary embodiment; and

[0029] Figure 5 It is a flowchart of a process implemented by a controller according to one or more embodiments. Detailed Implementation

[0030] The following description is exemplary in nature only and is not intended to limit this disclosure, its application, or use. It should be understood that in all the drawings, corresponding reference numerals denote the same or corresponding parts and features.

[0031] The embodiments of the systems and methods described in detail herein relate to a dual-chemistry propulsion system for eVTOL aircraft. Dual-chemistry refers to the use of both an energy cell and a power cell. While both energy cells and power cells typically generate electricity through chemical reactions (i.e., generating and storing energy in one step), they exhibit structural differences in their electrodes. Relatively speaking, the power cell comprises electrodes formed of porous materials and thinner coatings. This allows ions to move rapidly in and out of the electrodes (resulting in higher power output). In contrast, the energy cell comprises electrodes formed of denser materials and thicker coatings. This hinders the movement of ions in and out of the electrodes (limiting power output). Energy cells typically deliver a continuous current over long periods, while power cells typically deliver high current loads at intermittent intervals over short periods.

[0032] The detailed architecture of the dual-chemical propulsion system facilitates mode selection to maximize the use of energy and power cells during each different phase of eVTOL aircraft operation (e.g., takeoff, cruise (i.e., hovering or maneuvering), and landing). Multiple power packs provide on-demand power via DC-DC converters. The DC-DC converters are bidirectional, allowing the power packs to easily charge the energy packs in addition to redundancy. The controller manages the switching of the dual-chemical propulsion system, as described in detail.

[0033] According to an exemplary embodiment, Figure 1This is a block diagram of an eVTOL aircraft 100 with a dual chemical propulsion system 110. An exemplary eVTOL aircraft 100 is shown with four rotors 130, but according to alternative embodiments, any number of rotors 130 may be present. Reference Figure 2 The dual chemical propulsion system 110, described in further detail, includes a motor 120 that drives the rotor 130 to perform takeoff, cruise, and landing operations via the eVTOL aircraft 100. The controller 140 may be entirely part of the dual chemical propulsion system 110, or may be coupled to the dual chemical propulsion system 110, as shown in the figure.

[0034] Controller 140 can control the switching discussed for the dual-propellant chemical system 110, as described in detail, based on a mode or fault. Controller 140 may include processing circuitry, which may include application-specific integrated circuits (ASICs), electronic circuitry, a processor (shared, dedicated, or grouped) executing one or more software or firmware programs, memory, combinational logic circuitry, and / or other suitable components providing the aforementioned functionality. Controller 140 may also include a non-transitory computer-readable medium storing instructions that are processed by one or more processors of controller 140 to implement references. Figure 5 The discussion process.

[0035] Figure 2 This is a schematic diagram of a dual chemical propulsion system 110 for an eVTOL aircraft 100 according to one or more embodiments. Figure 2 The exemplary dual-chemical propulsion system 110 shown includes four subsystems 201-A, 201-B, 201-C, and 201-D (collectively referred to as 201). The four subsystems 201 can drive eight rotors 130, for example... Figure 1 The exemplary eVTOL aircraft 100 shows twice the number of rotors 130. That is, in the exemplary illustration, each subsystem 201 is shown as including two motors 120. However, as discussed further, any number of variations of this exemplary dual chemical propulsion system 110 are contemplated.

[0036] Adjacent subsystems 201 are separated by one of the inter-subsystem switches 250, designated SS1, SS2, and SS3. For example, subsystems 201-A and 201-B are separated by one of the inter-subsystem switches 250, namely switch SS1. During normal operation, all inter-subsystem switches 250 are open, allowing each rotor 130 to be independently connected to one of the subsystems 201 (i.e., subsystems 201 are electrically isolated). However, in the event of a failure in one of the subsystems 201, the corresponding inter-subsystem switch 250 (switches SS1, SS2, or SS3) can be closed to provide redundant propulsion power to the affected rotor 130. The inter-subsystem switches 250 can be controlled by controller 140 to provide this redundancy.

[0037] For readability, only components of one of subsystems 201-A are labeled and discussed. For example... Figure 2 As shown, each subsystem 201 includes the same components. As illustrated, subsystem 201-A includes a dual chemical energy storage system (ESS) 200, two motors 120, labeled motors M1 and M2, and corresponding inverters 240, labeled INV1 and INV2. Inverters 240 convert DC power from the dual chemical ESS 200 into AC power for operating the electric motors 120. According to an alternative embodiment, each subsystem 201 may include only one motor 120 or more than two motors 120, based on the power supplied by each dual chemical ESS 200 and the power required by each motor 120.

[0038] The dual-chemistry ESS 200 includes an energy sub-packet 210, a power sub-packet 220, and a DC-DC converter 230. According to alternative embodiments, the dual-chemistry ESS 200 may include two, three, or any other number of energy sub-packets 210 in parallel. Furthermore, the dual-chemistry ESS 200 may include two, three, or any number of power sub-packets 220 in parallel, which may require additional DC-DC converters 230. A greater number of energy sub-packets 210 and / or power sub-packets 220 can increase resolution and redundancy, but this increase must be balanced by the accompanying increase in weight and complexity.

[0039] As previously described, compared to the power sub-packet 220, the energy sub-packet 210 can provide a continuous current for a longer period of time, and compared to the energy sub-packet 210, the power sub-packet 220 can provide a higher current for a shorter duration. According to an exemplary embodiment, the voltage of the energy sub-packet 210 can be 800 volts (V), and the voltage of the power sub-packet 220 can be from 400V to 600V. The DC-DC converter 230 is bidirectional, enabling it to boost the voltage of the power sub-packet 220, allowing the power sub-packet 220 to power the motor 120 or to facilitate charging the power sub-packet 220 via the energy sub-packet 210. In an alternative embodiment, the voltage of the power sub-packet 220 can also be 800V, and the DC-DC converter 230 can regulate the voltage between the power sub-packet 220 and the energy sub-packet 210.

[0040] like Figure 2As shown, each subsystem 201 includes a subsystem switch 205, labeled as switch DS1, DS2, DS3, or DS4. The subsystem switch 205 of each subsystem 201 can be closed to electrically connect the dual-chemical ESS 200 of subsystem 201 to the motor 120 of subsystem 201. While the inter-subsystem switch 250 is open during normal operation to allow independent operation of each subsystem 201, the subsystem switch 205 is closed during normal operation to allow the motor 120 of subsystem 201 to be connected to the dual-chemical ESS 200 of subsystem 201.

[0041] If a given subsystem 201 fails in its dual-chemical ESS 200, the controller 140 can disconnect the subsystem switch 205 of the given subsystem 201 to disconnect the faulty dual-chemical ESS 200 from the motor 120. The controller 140 can then close the corresponding inter-subsystem switch 250 to supply power to the affected motor 120 using the dual-chemical ESS 200 of the adjacent subsystem 201. For example, if the dual-chemical ESS 200 of subsystem 201-A has a problem, the controller 140 can disconnect the subsystem switch 205 labeled DS1 to isolate the faulty dual-chemical ESS 200 from the motors 120 labeled M1 and M2. The controller 140 can then close the inter-subsystem switch 250 labeled SS1, such that the motors 120 labeled M1 and M2 are connected to the dual-chemical ESS 200 of subsystem 201-B.

[0042] Figure 3 This is a graph showing the power supplied by the dual-chemical ESS200 according to an exemplary embodiment. As shown, time, in seconds (s), is represented along one axis, and power, in kilowatt-hours (kWh), is represented along the vertical axis. Figure 3 The time periods shown are subdivided into time periods A, B, and C. Time period A relates to the takeoff duration of the eVTOL aircraft 100. Time period B relates to cruise, while time period C relates to the landing of the eVTOL aircraft 100. The energy sub-packet power output 310 is represented by dashed lines, and the power sub-packet power output 320 is represented by solid lines.

[0043] As shown in the diagram, during takeoff (i.e., time period A), the power output of the power subpack 320 is slightly higher than that of the energy subpack 310, but both supply power to their respective motors 120 consistently during takeoff. During cruise (i.e., time period B), only the energy subpack 210 supplies power to the motors 120 of the dual-chemical ESS200. As shown in the diagram, the power output of the power subpack 320 is zero. During landing (i.e., time period C), the power supply is similar to that during takeoff (i.e., time period A). Both the energy subpack 210 and the power subpack 220 supply power, but the power output of the power subpack 320 is slightly higher.

[0044] Figure 4 This is a graph representing the state of charge (SoC) of the energy sub-packet 210 and power sub-packet 220 of the exemplary dual-chemical ESS200 according to an exemplary embodiment. As shown, time, in seconds (s), is represented along one axis, and the SoC is represented along the vertical axis. Figure 3 As shown, the time period is subdivided into time periods A, B, and C, corresponding to takeoff, cruise, and landing, respectively. The energy sub-packet SoC410 is represented by dashed lines, and the power sub-packet SoC420 by solid lines. As shown, during takeoff (i.e., time period A), both the energy sub-packet SoC410 and the power sub-packet SoC420 decrease. This is because, when each power source continuously supplies power, the charge is depleted, such as... Figure 3 As shown. Similarly, as Figure 3 As shown, the power output of the power subpack 320 is higher than that of the energy subpack 310. Therefore, during takeoff (i.e., time period A), the power subpack SoC 420 decreases more than the energy subpack SoC 410.

[0045] During cruise (i.e., time period B), energy subpack 210 charges power subpack 220. As previously mentioned, this is achieved via bidirectional DC-DC converter 230. Therefore, energy subpack SoC 410 decreases, while power subpack SoC 420 increases during time period b. During landing (i.e., time period C), as during takeoff (i.e., time period A), both energy subpack 210 and power subpack 220 supply power to the motor 120 of the dual-chemical ESS 200. However, as... Figure 3 As shown, the power output of the power sub-packet 320 is higher than that of the energy sub-packet 310. Therefore, as shown in the figure, both the energy sub-packet SoC 410 and the power sub-packet SoC 420 decrease, but the decrease in the power sub-packet SoC 420 is greater than the decrease in the energy sub-packet SoC 410.

[0046] Figure 5 This is a process flow 500 implemented by controller 140 according to one or more embodiments. In block 510, the process includes acquiring information. For example, the information may indicate, for example... Figure 3 The indicated operating time period (A, B, or C) may indicate a fault in ESS200. Based on this information, in block 520, controller 140 may control one or more subsystem switches 205 or inter-subsystem switches 250, as described in detail above.

[0047] While the foregoing disclosure has been described with reference to exemplary embodiments, those skilled in the art will understand that various changes can be made and equivalents can replace its elements without departing from its scope. Furthermore, many modifications can be made to adapt particular situations or materials to the teachings of this disclosure without departing from its essential scope. Therefore, it is intended that this disclosure be limited to the specific embodiments disclosed, but will include all embodiments falling within its scope.

Claims

1. A system in an electrically powered vertical takeoff and landing aircraft, comprising: Two or more subsystems, each of which includes an energy storage system, each energy storage system being coupled to one or more motors that actuate one or more rotors of an electric vertical takeoff and landing aircraft: Each energy storage system includes one or more energy sub-packets, and Each energy storage system includes one or more power sub-packets, wherein one or more power sub-packets supply more power than one or more energy sub-packets, and one or more energy sub-packets supply stable power for a longer duration than one or more power sub-packets; Each energy storage system is connected to one or more motors via a switch; A group of one or more inter-subsystem switches, each of which connects adjacent subsystems in two or more subsystems when the inter-subsystem switch is in the closed state, and isolates adjacent subsystems in two or more subsystems when the inter-subsystem switch is in the open state. Each of the two or more subsystems is configured to receive power from the energy storage system of an adjacent subsystem connected in the two or more subsystems via an inter-subsystem switch in one or more of the set of inter-subsystem switches; The controller is configured to control the switching of each energy storage system and the switching between one or more subsystems; and The controller is configured to respond to a fault detected in a first subsystem among two or more subsystems by controlling the closing of a first inter-subsystem switch among one or more inter-subsystem switches, such that a second subsystem among two or more subsystems is connected to the first subsystem among two or more subsystems via the first inter-subsystem switch among one or more inter-subsystem switches.

2. The system according to claim 1, wherein, Each energy storage system also includes a bidirectional DC-DC converter configured to boost the voltage output of the one or more power sub-packets or to connect the one or more energy sub-packets to the one or more power sub-packets for charging the one or more power sub-packets.

3. The system according to claim 1, wherein, For each energy storage system, the one or more energy sub-packets and the one or more power sub-packets are configured to power the one or more motors during takeoff and landing of the electric vertical takeoff and landing aircraft, and for each energy storage system, only one or more energy sub-packets are configured to power the one or more motors during cruise of the electric vertical takeoff and landing aircraft, and the one or more energy sub-packets of each energy storage system are also configured to recharge the one or more power sub-packets of the energy storage system during cruise of the electric vertical takeoff and landing aircraft.

4. A method for assembling a system in an electric vertical takeoff and landing aircraft, comprising: Arrange two or more subsystems, each subsystem including an energy storage system, and connect each energy storage system to one or more motors that actuate one or more rotors of an electric vertical takeoff and landing aircraft; One or more energy sub-packets are arranged in each energy storage system; In each energy storage system, one or more power sub-packets are arranged, wherein one or more power sub-packets supply more power than one or more energy sub-packets, and one or more energy sub-packets supply stable power for a longer duration than one or more power sub-packets; as well as Each energy storage system is connected to one or more motors via a switch; A group of one or more inter-subsystem switches, each of which connects adjacent subsystems in two or more subsystems when the inter-subsystem switch is in the closed state, and isolates adjacent subsystems in two or more subsystems when the inter-subsystem switch is in the open state. Each of the two or more subsystems is configured to receive power from the energy storage system of an adjacent subsystem connected in the two or more subsystems via an inter-subsystem switch in one or more of the set of inter-subsystem switches; The controller is configured to control the switching of each energy storage system and the switching between one or more subsystems; and The controller is configured to respond to a fault detected in a first subsystem among two or more subsystems by controlling the closing of a first inter-subsystem switch among one or more inter-subsystem switches, such that a second subsystem among two or more subsystems is connected to the first subsystem among two or more subsystems via the first inter-subsystem switch among one or more inter-subsystem switches.

5. The method according to claim 4 further includes arranging a bidirectional DC-DC converter in each energy storage system to boost the voltage output of the one or more power sub-packets or to connect the one or more energy sub-packets to the one or more power sub-packets for charging the one or more power sub-packets.

6. The method of claim 4, further comprising configuring the one or more energy sub-packets and the one or more power sub-packets for each energy storage system to power the one or more motors during takeoff and landing of the electric vertical takeoff and landing aircraft, and configuring the one or more energy sub-packets and the one or more power sub-packets for each energy storage system such that only the one or more energy sub-packets power the one or more motors during cruise of the electric vertical takeoff and landing aircraft, and configuring the one or more energy sub-packets of each energy storage system to recharge the one or more power sub-packets of the energy storage system during cruise of the electric vertical takeoff and landing aircraft.

Images