Time-varying electrical load sharing in aircraft power distribution networks

Abstract

A power distribution network (306) of an electrical power system (300) of an aircraft is operated such that the power distribution network (306) sequentially adopts a plurality of different partial load sharing modes in a time-varying manner, providing partial load sharing across power sources (A, B, C, D) with respect to associated electrical loads (AA, BB, CC, DD) by sequentially switching between a plurality of different partial load sharing configurations of the power distribution network, each partial load sharing configuration being associated with a particular one of the partial load sharing modes.

Description

Technical Field

[0001] The present invention generally relates to an electrical power system for an aircraft, and to an aircraft having such an electrical power system. For example, the aircraft may be a canard-type aircraft having a plurality of lift / thrust units distributed along a front wing or canard and along a rear wing or main wing. The electrical power system includes a plurality of electrical loads, such as at least one of a plurality of lift / thrust units and a plurality of flap actuators, a plurality of power sources, such as a plurality of batteries or battery cells, and a power distribution network configured to connect the power sources to the electrical loads so that each electrical load can be driven by at least one associated power source via at least one associated power channel of the power distribution network. The present invention also relates to a method for operating an electrical power system for an aircraft. Background Art

[0002] Aircraft can generally be divided into fixed-wing and rotary-wing types. Fixed-wing aircraft typically include a plurality of flight control surfaces that, when controllably positioned, guide the aircraft from one destination to another. The number and type of flight control surfaces included in an aircraft can vary. Primary flight control surfaces are typically those used to control the movement of the aircraft relative to the pitch, yaw, and roll axes. Auxiliary flight control surfaces are typically those used to affect the lift or drag (or both) of the aircraft. Typical primary flight control surfaces include elevators, ailerons, and rudders, while typical auxiliary flight control surfaces include a plurality of flaps, slats, speed brakes, and spoilers.

[0003] Rotary wing aircraft, such as helicopters, typically do not have flight control surfaces separate from the wings that generate lift, but rather the wings that comprise the rotary wing have cyclic control of pitch and roll, as well as collective control of lift.

[0004] Furthermore, known aircraft have a vertical takeoff and landing capability based on propulsion engines that are rotatably mounted relative to the aircraft's lateral or pitch axis. The propulsion engines are controllably movable between a cruising flight position and a takeoff / landing position. In the cruising position, the engines provide forward thrust, and the aircraft's movement through the air is controlled by suitable flight control surfaces. In the takeoff / landing position, the propulsion engines are tilted downward to allow vertical takeoff or landing, depending on the thrust provided by the engines.

[0005] Based on publications US2016 / 0023754 A1 and US2016 / 0311522 A1, as well as other disclosures in the patent family, the applicant, Lilium eAircraft GmbH, has proposed an aircraft capable of vertical takeoff and landing and equipped with electrically driven ducted propellers. Furthermore, the applicant has developed an aircraft called the Lilium jet, a canard-type aircraft equipped with multiple front left, front right, rear left, and rear right engines in the form of electrically operated ducted propellers. These engines are mounted on the left and right front canards and the corresponding flaps of the left and right rear or main wings of the canard-type aircraft. The first test flight of this Lilium jet took place on October 1, 2019.

[0006] Another type of aircraft with vertical take-off and landing capabilities and electrically operated is known from US2020 / 0010187 A1. The aircraft has a plurality of propulsion assemblies, each of which includes an electric motor with two independent windings, whereby the electric motors are of a dual-supply type. A plurality of battery cells are associated with the electric motors in pairs, such that the first winding of each electric motor can be driven based on one of the battery cells and the second winding of each electric motor can be driven based on the other of the battery cells. Various power system architectures are disclosed that aim to achieve fault tolerance. According to a first embodiment, six electric motors and six battery cells are arranged in a ring architecture, such that each battery cell provides power to two electric motors and each electric motor receives power from two battery cells. According to a second embodiment, six electric motors and four battery cells are arranged in a dual configuration, such that each battery cell provides power to three electric motors and each electric motor receives power from two battery cells. According to a third embodiment, six electric motors and six battery cells are arranged in a hexagonal configuration, such that each battery cell provides power to two electric motors, and each electric motor receives power from two battery cells. According to a fourth embodiment, six electric motors and four battery cells are arranged in a star configuration, such that each battery cell provides power to three electric motors, and each electric motor receives power from two battery cells. According to a fifth embodiment, six electric motors and four battery cells are arranged in a star configuration, such that each battery cell provides power to three electric motors, and each electric motor receives power from two battery cells. According to a sixth embodiment, six electric motors and four battery cells are arranged in a mesh configuration, such that each battery cell provides power to three electric motors, and each electric motor receives power from two battery cells. In this mesh configuration, a first pair of battery cells jointly drives the two windings of an associated first electric motor, and a second pair of battery cells jointly drives the two windings of an associated second electric motor.

[0007] For any aircraft of this and any other type, the ability to withstand technical failures is one of the most important aspects, which essentially also concerns the aircraft's electrical power distribution network.

[0008] Power distribution networks used in safety-critical applications, such as aircraft, present an inherent tension: separation prevents fault propagation, while unification allows for effective load sharing across power sources. Typical approaches involve separate "power paths" that contain electrical faults within one path but do not benefit from load sharing across power sources. Any approach that uses unification is considered inherently unsafe, as electrical faults can propagate throughout the network and cause transient or steady-state power interruptions. Consequently, typical power distribution networks for safety-critical applications strictly adhere to a separation approach, thereby missing out on the benefits of unification.

[0009] According to conventional methods, in response to the occurrence of a fault, some kind of unification can be introduced to compensate for the fault. For example, conventional aircraft electrical systems can use electromechanical relays to provide unification, but the safety margin is reduced and therefore only used after a system failure.

[0010] It is known to use solid state and electromechanical switching devices in electrical power distribution networks for enabling and disabling the transfer of power between relevant parts of the electrical power distribution network depending on the prevailing circumstances and requirements.

[0011] Furthermore, it is known to use solid-state and electromechanical circuit protection arrangements (SPDs), such as solid-state and electromechanical circuit breakers, in power distribution networks for protecting downstream electrical wiring and electrical loads in the event of a short circuit. It is also known to use so-called "solid-state power controllers," often referred to as "SSPCs," as circuit protection arrangements in power distribution networks, including aircraft power distribution networks, in place of conventional electromechanical circuit breakers or even "old-fashioned" fuses.

[0012] A solid-state power controller (SSPC) is a circuit protection device similar to a fuse or another type of circuit breaker, and is therefore used to protect downstream wiring and electrical loads in the event of a short circuit. Compared to traditional electromechanical devices (fuses and circuit breakers), SSPCs have many advantages, such as being able to open more quickly when a short circuit occurs, being lighter and smaller, being software-resettable (no need to manually access them for maintenance or carry spare fuses), being flexible in terms of current and voltage trip ratings, being self-testing to avoid dormant faults, being able to log data about the robustness of the electrical system, and being able to perform additional functions, including switching devices. To this end, an SSPC includes a microcontroller, a communication interface for communicating data with a higher-level control entity, one or more load channels with a monitoring function for monitoring at least one electrical condition of each load channel, and a solid-state switch within each load channel, such as, for example, at least one metal oxide field-effect transistor (MOSFET), at least one bipolar junction transistor (BJT), a silicon-controlled rectifier (SCR), and a triac. The microcontroller monitors at least one electrical condition, including current flowing through the corresponding load channel to the corresponding load, and commands the solid-state switch to open if an electrical trip condition occurs, such as when the detected current exceeds a specific threshold. Multiple electrical trip conditions can be set to handle different types of electrical faults.

[0013] Various SSPC distribution architectures are known, such as a hierarchical architecture optimized for centralized control of a large number of SSPCs (e.g., >40 SPPs) from a vehicle management system (VMS) having at least one electrical system controller (ESC). Control is achieved via solid-state power managers (SSPMs), which are grouped with associated SSPCs in auxiliary power distribution units (SPDUs). A less hierarchical architecture is also known, typically used to centrally control a smaller number of SSPCs (e.g., <40 SPPs) in a vehicle management system (VMS). The SSPCs are grouped into primary power distribution units (PPDUs). The SSPC power distribution architecture can provide redundancy by including at least two electrical system controllers (ESCs) in the vehicle management system (VMS) and at least two solid-state power managers (SSPMs) in each auxiliary power distribution unit (SPDU).

[0014] For electric aircraft power systems that have multiple power sources in the form of batteries or battery cells for powering various electrical loads or aircraft equipment, unbalanced discharge of these power sources is undesirable and can cause problems. Furthermore, flight range can be negatively impacted by unbalanced battery discharge. To achieve high aircraft performance, it is advantageous if the corresponding electrical loads or aircraft equipment (such as each of the multiple lift / thrust units) can be driven by multiple independent power sources, at least in certain situations, such as when flight maneuvers require increased drive power for the lift / thrust units.

[0015] In view of the foregoing, an object of the present invention is to provide an electrical power system for an aircraft and a corresponding operating method which allow adequate recovery from electrical faults to be achieved in an efficient manner.

[0016] Another object of the present invention is to provide an electric power system for an aircraft and a corresponding operating method which achieve high aircraft performance in terms of flight maneuvers requiring increased drive power and achievable flight range.

[0017] Another object of the invention is to provide an electrical power system for an aircraft and a corresponding operating method which allow a uniform discharge of a power source in the form of a battery or battery unit. Summary of the Invention

[0018] To achieve at least one of these objectives, the present invention provides an electrical power system for an aircraft, the electrical power system comprising a plurality of electrical loads, a plurality of power sources, and a power distribution network, the power distribution network being configured to connect the power sources with the electrical loads such that each electrical load can be driven by at least one associated power source via at least one associated power channel of the power distribution network.

[0019] The power distribution network includes at least one of a circuit protection arrangement and a circuit switching arrangement having a plurality of switchable or interruptible power links, wherein each power link has two connection ports, and wherein each power link is configured to connect the connection ports in a first operating mode for transmitting power from a driving power channel or a driving power channel portion connected to one of the connection ports to a driven power channel or a driven power channel portion connected to another of the connection ports, and is configured to interrupt the connection between the connection ports in a second operating mode for preventing power transmission between the driving power channel or the driving power channel portion and the driven power channel or the driven power channel portion.

[0020] The power distribution network is configured to provide partial load sharing across the power sources with respect to associated electrical loads in a time-varying manner according to a plurality of different partial load sharing modes sequentially adopted by the power distribution network by sequentially switching between a plurality of different partial load sharing configurations of the power distribution network, each partial load sharing configuration being associated with a particular one of the partial load sharing modes.

[0021] The power distribution network is also configured such that each power supply in at least one group of the multiple power supplies is associated with at least one, preferably at least two, of different partial load sharing modes, and each electric load in at least one group of the multiple electric loads is associated with at least one, preferably at least two, of different partial load sharing modes, and is configured such that each partial load sharing mode has associated multiple power supplies and multiple electric loads, so that the power supplies and electric loads form a common load sharing group or multiple separate load sharing groups of the corresponding partial load sharing mode, wherein the power distribution network, when adopting the corresponding partial load sharing mode, provides load sharing between the power supplies of the associated common load sharing group with respect to the electric loads of the associated common load sharing group, or provides respective partial load sharing for each of the separate load sharing groups, which is load sharing across the power supplies of each corresponding separate load sharing group with respect to the electric loads of this corresponding separate load sharing group, rather than any load sharing across the separate load sharing groups.

[0022] The proposed power system combines the key advantages of both unified and isolated power grids. Partial load sharing between power sources allows for a targeted unification of the network's power channels. In principle, all, or at least most, of the advantages of a unified power distribution network can be achieved without requiring complete unification of the entire network. The proposed partial unification appears particularly advantageous for load sharing between power sources such as batteries.

[0023] The power distribution network can be configured to operate in at least one normal operating mode and at least one electrical fault mitigation operating mode. In this regard, it is further proposed that the power distribution network be configured to sequentially employ different partial load sharing modes in the normal operating mode. Thus, in the normal operating mode, the power distribution network provides the proposed partial load sharing across the power sources.

[0024] In the electrical fault mitigation mode, the power distribution network preferably provides electrical fault isolation, such that the network portion of the power distribution network containing the electrical fault is isolated from at least one other network portion of the power distribution network by at least one power link in the second operating mode. Thus, the proposed power system allows combining the advantages of a unified power grid with the advantages of isolated power grids, while also achieving resilience to electrical faults. In the normal operating mode, assumed during normal flight operations of an aircraft, the sequentially varying partial unification between the power channels of the network allows for effective partial load sharing across the power sources. If an electrical fault occurs, the power distribution network adopts the electrical fault mitigation operating mode, which provides isolation between the relevant power channels and, thereby, isolates the electrical fault.

[0025] Based on the invention, a partially unified electrical network with time-varying partial unification is achieved, which provides for normal operation of the aircraft substantially all the advantages resulting from the unified approach, although according to conventional wisdom the unified approach is considered unsafe for safety-critical applications like aviation.

[0026] Thus, the power system of the present invention differs significantly from conventional aircraft power distribution networks, which, during normal aircraft operation, utilize separate power paths with specific electrical loads irrevocably assigned to specific power sources. This assignment results in inconsistent power demands on the power sources, which is suboptimal, particularly for battery electric vehicle / aircraft applications. Furthermore, following a power path failure, separation must be suspended by introducing some form of unification in order to provide continuous power to the electrical loads. This loss of separation results in a reduction in safety.

[0027] According to the present invention, a completely different approach is pursued. According to a plurality of partial load-sharing configurations, multiple or all power sources and multiple or all electrical loads are partially unified or connected together in a time-varying manner that is optimal for load sharing across the power sources and, thereby, for uniform power demand on the power sources. By appropriately associating these power sources in partial load-sharing configurations, uniform discharge of the batteries used as power sources can be achieved. Any electrical fault is safely isolated before it propagates, and then, after the fault is eliminated, unity can be safely re-established and the network returned to normal operation. By appropriately associating power sources and loads in partial load-sharing configurations, one can provide resilience to electrical faults even during normal operation, without relying on immediate fault isolation.

[0028] Fault isolation within multiple partial load-sharing configurations enables easier and faster fault elimination compared to a standard unified network, as fault elimination is easier in a partially unified and therefore partially separated power distribution network when only a limited number of power sources contribute to the fault, as opposed to the many power sources in a standard unified network. Furthermore, sequential switching between partial load-sharing configurations facilitates identification of which power channel, power source, or load is directly affected by the electrical fault.

[0029] According to a preferred embodiment, it is also advantageous to use partial load sharing across the power supplies in the electrical fault mitigation mode. In this regard, it is proposed that the power distribution network is configured to provide partial load sharing across the power supplies in the electrical fault mitigation mode with respect to the associated electrical loads in a time-varying manner by sequentially switching between a plurality of different partial fault isolation load sharing configurations of the power distribution network, according to a plurality of different partial fault isolation load sharing modes sequentially adopted by the power distribution network, each partial fault isolation load sharing configuration being associated with a specific one of the partial fault isolation load sharing modes and providing electrical fault isolation.

[0030] By associating power supplies and electrical loads with load sharing modes and load sharing groups in different ways, such partial load sharing across power supplies can be achieved in the electrical fault mitigation mode similar to the partial load sharing across power supplies in the normal operating mode. In this regard, it is proposed that the power distribution network is configured so that in the at least one group of power supplies, multiple or all power supplies that are not directly affected by the power fault are each associated with at least one, preferably at least two, of different partial fault isolation load sharing modes, and so that in the at least one group of electrical loads, multiple or all electrical loads that are not directly affected by the power fault are each associated with at least one, preferably at least two, of different partial fault isolation load sharing modes, and so that each partial fault isolation load sharing mode is associated with multiple power supplies and multiple electrical loads, so that the power supplies and electrical loads form a common fault isolation load sharing group or multiple separate fault isolation load sharing groups of the corresponding partial fault isolation load sharing modes. When the power distribution network adopts a corresponding partial fault isolation load sharing mode, the power distribution network provides load sharing of the power supplies of the associated common fault isolation load sharing group with respect to the electrical loads of the associated common fault isolation load sharing group, or provides respective partial load sharing for each of the separate fault isolation load sharing groups, which is load sharing of the power supplies of each corresponding separate fault isolation load sharing group with respect to the electrical loads of this corresponding separate fault isolation load sharing group, rather than any load sharing across the separate fault isolation load sharing groups; and wherein at least one power supply and / or at least one electrical load is excluded from the load sharing used to achieve electrical fault isolation.

[0031] If desired, multiple electric loads of the same type can form an electric load group. Alternatively, multiple electric loads of different types can form an electric load group. Multiple different groups of this type can be provided.

[0032] According to a preferred embodiment, the electric power distribution network is configured to provide load sharing across all power sections with respect to all electric loads according to a plurality of different partial load sharing modes employed in sequence.

[0033] There are no restrictions regarding the architecture and structure of the power distribution network and the arrangement of its power channels. According to a preferred method, the power distribution network can include multiple power channels of the first category; each power channel of the first category is associated with at least one associated power source that is not associated with another power channel of the first category, and each power channel of the first category is associated with at least one electrical load that is not associated with another power channel of the first category, such that at least one associated power source is connected or connectable to the at least one associated electrical load via the corresponding power channel of the first category, so that the at least one power source can drive the at least one electrical load via the corresponding power channel of the first category without having to drive the at least one electrical load via another power channel of the first category. According to the conventional method mentioned above, these first category power channels are isolated from each other at all times or during normal operation of the aircraft.

[0034] Partial unification between a plurality of power channels of the first category can be achieved by providing power channels of another category in addition to the power channels of the first category. In this regard, it is proposed that a plurality of power channels of the first category are connected or connectable via a connecting channel arrangement of an electric power distribution network, the connecting channel arrangement comprising one or more power channels of a second category, for achieving partial load sharing of the electrical loads associated with the power channels of the first category across power sources associated with at least one group of the power channels of the first category or associated with all the power channels of the first category by transmitting power between the power channels of the first category via at least one power channel of the second category.

[0035] The connecting channel arrangement can advantageously include at least one connecting channel, which is associated with at least two, preferably at least three power channels of the first class, and the power channels of the first class are connected or connectable to the connecting channel via corresponding power channels of the second class associated with the corresponding power channels of the first class.

[0036] The connecting channel arrangement may advantageously include one or more power channels of the second type, wherein each power channel of the second type has associated therewith two power channels of the first type, such that the two power channels of the first type are connected or connectable via the power channel of the second type, for achieving load sharing across the power sources associated with the two power channels of the first type with respect to the electrical load associated with the two power channels of the first type by transmitting power between the two power channels of the first type via the power channel of the second type. In this regard, it is preferred that power transmission between the two power channels of the first type via the power channel of the second type does not necessarily involve power transmission via another power channel of the second type.

[0037] The power channels of the first category and the power channels of the second category may be arranged in various different ways or according to various types. Generally, if it is appropriate that the power distribution network includes two, three or more power channels of the second category, the power channels of the second category are associated with the plurality of power channels of the first category in such a way that each of the plurality of power channels of the first category is connected or connectable to at least one other power channel of the first category via a corresponding power channel of the second category.

[0038] In this regard, according to the first embodiment, the method also proposes that each of the multiple power channels of the first class or the subgroup of the multiple power channels of the first class is connected or connectable to the other two power channels of the multiple power channels of the first class or the subgroup of the power channels of the first class via the corresponding power channels of the second class, so as to achieve partial load sharing across the electrical load in the ring topology.

[0039] According to a second embodiment of the present invention, two power channels of the plurality of power channels of the first type or of the subgroup of the plurality of power channels of the first type are connected or connectable to only one other power channel of the plurality of power channels of the first type or of the subgroup ...

[0040] According to a third implementation method, alternative to the first and second implementation methods or implemented in conjunction with one or both of the first and second implementation methods, it is proposed that one power channel of the plurality of power channels of the first type or a subset of the plurality of power channels of the first type is connected or connectable to at least three other power channels of the plurality of power channels of the first type or the subset of the plurality of power channels of the first type via a corresponding power channel of the second type, so as to achieve partial load sharing across the electrical load in the star topology. If desired, each of these at least three other power channels can be the starting power channel of a power channel circuit including the plurality of power channels according to the circuit topology.

[0041] According to a preferred variant of the method of the third embodiment, it is provided that a connecting channel of the connecting channel arrangement is connected or connectable to the plurality of power channels of the first type or to at least three power channels of the subset of power channels of the first type via corresponding power channels of the second type, so that partial load sharing across the electrical load in a star topology is achieved. If desired, each of these at least three additional power channels can again be the starting power channel of a power channel circuit comprising a plurality of power channels according to the circuit topology.

[0042] This variation of the third embodiment method has a significant advantage because the connecting channels, rather than the first-class power channels, serve as the hub or center of the star topology, making this hub or center less likely to be directly affected by an electrical fault. This hub or center can avoid any associated first-class power channels and, therefore, any electrical faults that might occur there due to the corresponding second-class power links. This allows partial load sharing to be maintained even in the event of an electrical fault that directly affects any of the first-class power channels.

[0043] Preferably, each of the first-class power channels includes a first-class power link, which allows power to be transmitted from at least one associated power source to at least one associated electric load via this first-class power link in its first operating mode, and prohibits power from being transmitted from at least one associated power source to at least one associated electric load via this first-class power link in its second operating mode.

[0044] Such power links of the first category may essentially correspond to conventional circuit breakers, such as fuses, or electromechanical or solid-state circuit protection arrangements, which are used to protect downstream electrical wiring and loads in the event of a short circuit. Thus, each power link of the first category may be configured to change its operating mode from a first operating mode to a second operating mode in response to at least one preset or presettable electrical trip condition indicative of an electrical fault.

[0045] The first type of power link can be configured to trip based on one or more predetermined electrical trip conditions. Any suitable electrical trip condition known in the art can be implemented. Such an implementation can be in hardware, such as conventional fuses and circuit breakers, which have predefined electrical trip conditions, such as a set of predefined trip curves implemented by the manufacturer, so that when the device is commanded to change the trip curve, the device part number must be changed.

[0046] For example, the at least one predefined electrical trip condition may include at least one of: i) a current transmitted via the power link of the first type and exceeding a predefined current trip threshold, and ii) an i2t amount representing electrical energy consumed via the power link of the first type within a predefined reference time interval and exceeding a predetermined electrical i2t trip threshold.

[0047] According to a preferred embodiment, each power link of the first category is provided by an electromechanical or solid-state circuit protection arrangement of the power distribution network, for example by an electromechanical or solid-state circuit breaker. Solid-state devices are preferred. It is not excluded that the power links of the first category are implemented by one or more solid-state power controllers (SSPC) of the power distribution network.

[0048] In order to realize that the power distribution network can adopt a configuration that provides partial unification and a configuration that provides partial separation, it is proposed that each of the second-class power channels includes a second-class power link, and the second-class power link allows power to be transmitted between the first-class power channels via the second-class power link in its first operating mode, and prohibits power from being transmitted between the first-class power channels via the second-class power link in its second operating mode.

[0049] Advantageously, each power link of the second category can be provided by an associated electromechanical or solid-state circuit switching device of the power distribution network. In principle, relatively simple switching devices operating under the control of an appropriate controller can be used. However, it is not excluded that one or more solid-state power controllers (SSPCs) of the power distribution network implement one or more power links of the second category, for example if additional or alternative functions are provided in addition to switching between different partial load sharing configurations.

[0050] Typically, it is appropriate that the power distribution network includes at least one controller, preferably at least one superior controller, configured to control the power link of the second type to switch between its first and second operating modes, such that the power distribution network switches sequentially between a plurality of different partial load sharing configurations or between a plurality of different partial fault isolation load sharing configurations. Such a controller may also be configured to detect the occurrence of an electrical fault in the power distribution network and control the network so that it adopts an electrical fault mitigation operating mode.

[0051] To achieve at least one of the above objectives, the present invention also provides a method for operating an electrical power system of an aircraft, the electrical power system comprising a plurality of electrical loads, a plurality of electrical power sources, and a power distribution network, the power distribution network being configured to connect the electrical power sources to the electrical loads so that each electrical load can be driven by at least one associated electrical power source via at least one associated power channel of the power distribution network. The power distribution network comprises a plurality of switchable or interruptible power links, each power link being provided within a respective power channel of the power distribution network and configured to enable power to be transmitted via the respective power channel in a first operating mode of the power link and to prevent power from being transmitted via the respective power channel in a second operating mode of the power link.

[0052] The method includes operating an electric power distribution network so that the electric power distribution network sequentially adopts a plurality of different partial load sharing modes in a time-varying manner, which provides partial load sharing across the power sources with respect to associated electric loads by sequentially switching between a plurality of different partial load sharing configurations of the electric power distribution network, each partial load sharing configuration being associated with a particular one of the partial load sharing modes.

[0053] Each power supply in at least one group of the multiple power supplies is associated with at least one, preferably at least two, of different partial load sharing modes, and each electric load in at least one group of the multiple electric loads is associated with at least one, preferably at least two, of different partial load sharing modes, and each partial load sharing mode has associated multiple power supplies and multiple electric loads, so that the power supplies and the electric loads form a common load sharing group or multiple separate load sharing groups of the corresponding partial load sharing mode, wherein the power distribution network, when it operates in accordance with the corresponding partial load sharing mode, provides load sharing of the power supplies across the associated common load sharing group with respect to the electric loads of the associated common load sharing group, or provides respective partial load sharing for each of the separate load sharing groups, which is load sharing of the power supplies across each corresponding separate load sharing group with respect to the electric loads of this corresponding separate load sharing group, rather than any load sharing across the said separate load sharing groups.

[0054] The method of the present invention provides a combination of the advantages of the conventional split approach and the advantages of the conventional unified approach through partial load sharing discussed above with respect to the power system of the present invention.

[0055] The method may include operating the power distribution network in at least one normal operating mode that provides said partial load sharing across the power sources with respect to associated electrical loads by sequentially switching between a plurality of different partial load sharing configurations of the power distribution network. Furthermore, the method may include operating the power distribution network in at least one electrical fault mitigation operating mode that provides electrical fault isolation such that a network portion of the power distribution network comprising the electrical fault is isolated from at least one other network portion of the power distribution network by at least one power link in a second operating mode.

[0056] Thus, the method of the invention provides a combination of the advantages of conventional separation methods with the advantages of conventional unification methods, also with the aim of not compromising security against critical faults, as discussed above with respect to the power system of the invention.

[0057] In this regard, it is further proposed that the method comprises operating the power distribution network in an electrical fault mitigation operating mode so that it sequentially adopts a plurality of different partial fault isolation load sharing modes in a time-varying manner, which provides partial fault isolation load sharing across power sources with respect to associated electrical loads by sequentially switching between a plurality of different partial fault isolation load sharing configurations of the power distribution network, each partial fault isolation load sharing configuration being associated with a specific one of the partial fault isolation load sharing modes. In the at least one group of power supplies, multiple or all power supplies that are not directly affected by the power fault are each associated with a different partial fault isolation load sharing mode and at least one, preferably at least two, of the at least one group of electrical loads, multiple or all electrical loads that are not directly affected by the power fault are each associated with at least one, preferably at least two, of a different partial fault isolation load sharing mode, and each partial load fault isolation load sharing mode is associated with multiple power supplies and multiple electrical loads, so that the power supplies and electrical loads form a common load sharing group or multiple separate load sharing groups of the corresponding partial fault isolation load sharing mode, wherein the power distribution network, when operating in accordance with the corresponding partial load sharing mode, provides load sharing of the power supplies of the associated common fault isolation load sharing group across the associated common fault isolation load sharing group, or provides respective partial load sharing for each separate fault isolation load sharing group, which is load sharing of the power supplies of each corresponding separate fault isolation load sharing group across the corresponding separate fault isolation load sharing group, rather than any load sharing across the separate fault isolation load sharing group. The method includes operating the power distribution network in an electrical fault mitigation mode such that at least one power source and / or at least one electrical load is excluded from load sharing to achieve electrical fault isolation.

[0058] The power distribution network of the power system may include power channels of a first class, each power channel of the first class including a corresponding power link of the first class. In addition, the power distribution network of the power system may include one or more power channels of a second class, each power channel of the second class including a corresponding power link of the second class. Each power channel of the first class may connect at least one associated power source with at least one associated electric load, so that at least one associated power source can drive at least one associated electric load without having to involve driving via another power channel of the first class. In addition, each power channel of the second class may be connected or connectable to at least two associated power channels of the first class, so that power can be transmitted between the power channels of the first class, so that partial load sharing of the electric loads associated with these power channels of the first class across the power sources associated with these power channels of the first class can be achieved.

[0059] According to the invention, the method comprises repeatedly switching the power link of the second type between its first and second operating modes such that the power distribution network switches sequentially between a plurality of different partial load sharing configurations or between a plurality of different partial fault isolation load sharing configurations.

[0060] With respect to such an electric power distribution network, the method may advantageously further comprise changing the operation mode of one or more of the power links of the second category from a first operation mode to a second operation mode for isolating the electrical fault in the electrical fault mitigation mode.

[0061] In view of the foregoing, the present invention provides a method for providing load sharing capabilities to an electric power distribution network using multiple battery sources while avoiding a level of uniformity at which an electrical fault would be able to propagate unsafely across the electric power distribution network. Advantageously, multiple network channels of the network can be allocated for partial load sharing, and a multi-level switching method can be implemented to allow safe load sharing while preventing electrical fault propagation.

[0062] The invention also provides a universal power system for an aircraft, characterized in that it is configured to operate according to the method of the invention.

[0063] In principle, the power system and method for operating the power system of the present invention can be applied to or provided within any type of aircraft. Thus, the present invention provides an aircraft comprising the power system described above, or comprising a power system configured to operate according to the method of the present invention. The aircraft is preferably at least one of a single-pilot aircraft, an aircraft capable of vertical takeoff and landing, and a canard-type aircraft. Furthermore, the aircraft is preferably an electric aircraft, as discussed above.

[0064] According to a preferred embodiment, the power system may include at least one group of common type electrical loads in the form of aircraft equipment, which are critical to maintaining safe flight operation of the aircraft, wherein the aircraft equipment is arranged in a certain number and configuration at one or both of the fuselage of the aircraft and the wings of the aircraft to achieve fault resistance, so that each subgroup of the multiple aircraft equipment can fail without endangering the flight capability and controllability of the aircraft, and each subgroup of the multiple aircraft equipment includes at least two common types of aircraft equipment.

[0065] A common type of aircraft equipment may be an electric lift / thrust unit for the aircraft.

[0066] Advantageously, the or each respective subgroup of aircraft equipment is associated with a specific common power channel of the power distribution network of the power system for being commonly driven via this common power channel, and wherein the or each respective subgroup of aircraft equipment is provided to be arranged in a symmetrically distributed manner at one or both of the fuselage of the aircraft and the wings of the aircraft, so that an electrical fault directly or indirectly affecting the common power channel and causing a fault in the aircraft equipment of this subgroup does not endanger the flight capability and controllability of the aircraft.

[0067] As previously considered, the corresponding specific common power channel of the electricity distribution network may be a power channel of the first type.As previously considered, partial load sharing across a plurality or all subgroups may be achieved via power links of the second type.

[0068] Preferably, each aircraft device is associated with at least one or more of the different partial load sharing modes, such that the aircraft devices form a common load sharing group or a plurality of separate load sharing groups of the corresponding partial load sharing modes. In this regard, it is further proposed that the aircraft devices are associated with the different partial load sharing modes in such a manner as to form the corresponding common load sharing group or the corresponding plurality of separate load sharing groups, and that, for each different partial load sharing mode, the aircraft devices of the common load sharing group or each of the plurality of separate load sharing groups are symmetrically arranged on one or both of the fuselage and wings of the aircraft in such a manner that an electrical fault that directly or indirectly affects the aircraft devices of the corresponding common load sharing group or the corresponding separate load sharing group and causes a fault in the aircraft devices does not endanger the flight capability and controllability of the aircraft.

[0069] According to this proposal, a failure of any common load sharing group or multiple separate load sharing groups, such as a failure caused by a short circuit in the electrical loads or power supply, will not jeopardize the flight capability and controllability of the aircraft.

[0070] When such an electrical fault is detected, a fault mitigation operating mode of the electrical power distribution network of the aircraft may become active. Preferably, such a fault mitigation operating mode provides for continued partial load sharing in a modified manner that isolates the electrical fault. For example, in the electrical fault mitigation operating mode, specific load sharing groups or separate load sharing groups affected by the electrical fault may be excluded from further partial load sharing. More suitably, in the electrical fault mitigation operating mode, electrical loads and / or power sources that are the source of the electrical fault or of a power channel (in particular the first power channel) directly affected by the electrical fault may be excluded from further partial load sharing. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 The flight control system of an aircraft is schematically shown, which has a user interface for the pilot, a redundant flight control computer system, and an electronic or optoelectronic bus system connecting aircraft equipment belonging to the aircraft's power system (not shown) with the flight control computer system.

[0072] Figure 2 The diagram is a schematic top view of a canard-type aircraft of a first variant, which can be realized as a single-pilot aircraft with VTOL capability and can be provided with an electric power system according to the present invention including aircraft equipment and a power supply for powering the aircraft equipment.

[0073] Figure 3 is a schematic top view of a second variant of a canard-type aircraft, which can be realized as a single-pilot aircraft with VTOL capability and can be provided with an electric power system according to the present invention.

[0074] Figure 4 Two types of lift / thrust units are schematically shown in sub-figures a) and b), having three propulsion engines mounted to or integrated with the flaps, as shown in sub-figure a), or having one propulsion engine mounted to or integrated with the flaps, as shown in sub-figure b).

[0075] Figure 5 In sub-figures a), b), c) and d) the side view is shown. Figure 4 A lift / thrust unit and a corresponding aircraft wing, wherein the flaps are at four different deflection angles relative to the wing.

[0076] Figure 6 A general electrical power system for an aircraft is shown schematically.

[0077] Figure 7 An electrical power system of an aircraft is schematically shown with an electrical power distribution network illustrating a first conventional approach.

[0078] Figure 8 An electrical power system of an aircraft is schematically shown with an electrical power distribution network illustrating the second and third conventional methods.

[0079] Figure 9 The electrical system of an aircraft is schematically shown, illustrating Figure 8 A variation of the conventional method.

[0080] Figure 10 A suitable wiring topology of a power distribution network of an electrical system of an aircraft is schematically illustrated, on the basis of which the invention can be implemented.

[0081] Figure 11 Schematically illustrates the Figure 10 A first variant of the network topology.

[0082] Figure 12 Schematically illustrates the Figure 10 A second variation of the network topology.

[0083] Figure 13 A suitable ring topology of a power distribution network of an electrical power system of an aircraft is schematically illustrated, on the basis of which the invention can be implemented.

[0084] Figure 14 A suitable star topology of a power distribution network of an electrical power system of an aircraft is schematically illustrated, on the basis of which the invention can be implemented.

[0085] Figure 15 A suitable star topology of a power distribution network of an electrical system of an aircraft is schematically illustrated, which is particularly advantageous and on the basis of which the invention can be implemented.

[0086] Figure 16 In sub-figure a) the following diagram is schematically shown: Figure 2 , and in sub-figure b) an undesirable configuration of the electrical system of the aircraft is illustrated, and in sub-figure c) a desired configuration of the electrical system of the aircraft is illustrated. DETAILED DESCRIPTION

[0087] The following describes a "first method" and a "second method" for achieving the key advantages of conventional power network segmentation and conventional power network unification in an advantageous and synergistic manner. Only the "second method" is a method of the present invention, and therefore the examples provided for implementing the "second method" are non-limiting, illustrative embodiments of the present invention. The "first method" and the examples provided for implementing the "first method" are provided solely for comparative purposes and to complete the present disclosure.

[0088] Figures 1 to 5 A non-limiting example of an aircraft is shown which may be designed with an electrical power system according to the invention.

[0089] Figure 1 A non-limiting example of a flight control system 10 for an aircraft is schematically shown and described. The flight control system has a flight control computer system 12, which can be implemented according to conventional concepts, particularly those providing redundancy. One example is a conventional triple architecture with three redundant flight control computers 12a, 12b, and 12c. These computers can be redundantly connected to the pilot user interface and to the components and devices of the aircraft to be controlled based on the pilot's commands. Examples of conventional redundancy concepts include US Pat. No. 7,337,044 B2, US Pat. No. 8,935,015 B2, and US Pat. No. 8,818,575 B2.

[0090] exist Figure 1 , various components of the aircraft are schematically represented by elements 14 to 20, which may represent various aircraft equipment, such as sensors, actuators (such as actuators for controllably moving flight control surfaces such as flaps), propulsion engines, etc., which may be controlled and monitored by the flight control computer system 12 via an appropriate control bus system (e.g., a CAN bus system 22).

[0091] The flight control system 10 also includes a pilot user interface that may include a left stick assembly 30 a having a left stick 32 a with a side stick sensor assembly 38 a and a right stick assembly 30 b having a right stick 32 b with a side stick sensor assembly 38 a. The flight control computer system 12 may receive control signals from the pilot user interface via electronic or optical connection links 42 a and 42 b.

[0092] Figure 2 and Figure 3 Two canard-type aircraft are shown as non-limiting examples to which the present invention can be applied, and which can have the following configurations: Figure 1 The flight control system 10 is shown. A canard-type aircraft 200 has a fixed left rear or main wing 202 and a fixed right rear or main wing 204 at the rear portion of the aircraft's fuselage 203, and a fixed left front or canard wing 206 and a fixed right front or canard wing 208 at the front portion of the aircraft's fuselage. Each wing is provided with an array of a plurality of flaps 210, 212, 214, and 216, respectively. For example, each front wing or canard may be provided with at least six flaps, and each rear wing or main wing may be provided with at least twelve flaps.

[0093] Figure 2The embodiment shown has two flaps per front wing or canard and four flaps per rear wing or main wing, while Figure 3 The embodiment shown has six flaps per front wing or canard, and twelve flaps per rear wing or main wing.

[0094] The flaps of the two embodiments are pivotally or movably mounted to the corresponding wings and can be pivoted around a pivot axis or moved by a pivoting movable member by a corresponding electric actuator arrangement, preferably independently of each other for each flap. Each flap can pivot between a first operating position at the top and a second operating position at the bottom. Each flap can take a position of minimum or zero inclination relative to the longitudinal axis of the aircraft, which may be the first operating position at the top, and a position of maximum downward inclination relative to the longitudinal axis of the aircraft, which may be the second operating position at the bottom. However, if the position of maximum downward inclination corresponds to the vertical direction of the flaps, the lower second operating position can alternatively be a position exceeding the position of maximum downward inclination so that the flaps point slightly forward.

[0095] Each of these flaps is equipped with at least one propulsion engine in the form of an electrically operated ducted propeller. The ducted propeller is preferably mounted to the upper surface of the corresponding flap. Alternatively, the propulsion engine can be integrated into the corresponding flap in such a way that the air duct of the corresponding propulsion engine is located above and aligned with the upper surface of the corresponding front or rear wing, and the corresponding ducted propeller rotates in the air duct.

[0096] Preferably, the flaps can adopt a position corresponding to a lower second operating position or another operating position between the first and second operating positions, in which the ducted propeller provides only downward vertical thrust, which provides the aircraft with vertical take-off and landing (VTOL) capability. In the upper first operating position or another operating position between the first and second operating positions, in which the flaps are extended at a minimum angle in the longitudinal direction or relative to the longitudinal direction of the aircraft, the operating ducted propeller provides maximum forward thrust for the aircraft. The flaps are not only used to control the thrust direction of the propulsion engine or propulsion module, but also used to act as flight control surfaces, affecting the movement of the aircraft in the air according to the usual aerodynamic principles.

[0097] exist Figure 2 In the illustrated embodiment, the flaps are provided with a propulsion module into which a plurality of propulsion engines in the form of ducted propellers are integrated. For example, such a propulsion module may include three such propulsion engines, so that each flap is provided with three propulsion engines in the form of corresponding ducted propellers. In this case, the aircraft is provided with a total of 36 propulsion engines.

[0098] Figure 4Sub-figure a) shows a schematic diagram of such a propulsion module 230 having an array of three propulsion engines 232a, 232b and 232c and mounted to a flap 234, which may be Figure 2 Any of the flaps 210 , 212 , 214 , and 216 shown.

[0099] exist Figure 3 In the embodiment shown, each flap is provided with a corresponding propulsion engine in the form of a ducted propeller. Thus, the aircraft is provided with a total of 36 propulsion engines.

[0100] Figure 4 Sub-figure b) of FIG schematically shows such a flap 234 with a propulsion engine 232 installed. The flap 234 may be Figure 3 Any one of the flaps 210 , 212 , 214 and 216 .

[0101] Figure 4 The corresponding flaps 234 with the propulsion modules 230 or propulsion engines 232 are schematically shown in a view from the rear of the aircraft.

[0102] Figure 5 A side view of a corresponding wing 236 and a corresponding flap 234 of an aircraft is schematically shown, wherein the wing 236 may be Figure 2 and Figure 3 For any one of the wings 202, 204, 206 and 208, the corresponding propulsion module 230 or the corresponding propulsion engine 232 is installed to the corresponding flap 234 for obtaining different deflection angles of the flap relative to the wing. For example, Figure 5 The minimum or zero deflection angle shown in sub-diagram a) of FIG provides the maximum forward thrust for the aircraft, while Figure 5 The maximum deflection angle, or 90 degrees, shown in sub-diagram d) of FIG provides the maximum or only vertical downward thrust to achieve the vertical takeoff and landing (VTOL) capability of the aircraft. The maximum deflection angle can even be greater than 90 degrees, thereby providing thrust in a direction having a downward component and a rearward component.

[0103] like Figure 5 Subgraph b) and Figure 5 The intermediate deflection angle of the flap shown in sub-diagram c) of FIG provides thrust in a direction with a downward component and a forward component, as follows from the corresponding deflection angle. This deflection angle can preferably be continuously varied between a minimum and a maximum deflection angle. A suitable flap actuator or flap actuators acting between the respective wing 236 and the respective flap 234 are arranged at Figure 5 A suitable pivot joint or pivot joints for pivotally connecting the flap 234 to the wing 236 are arranged in Figure 5 Schematically represented by element 242.

[0104] exist Figure 3 In the embodiment, the lift / thrust units each have flaps 234 and propulsion engines 232 and Figure 4 Subgraph b) and Figure 5 The flap actuator or flap actuator arrangement 240 shown, these lift / thrust units have Figure 3 The illustration in FIG. 1 shows the associated identification numbers associated with the wings and canards. The six flaps or lift / thrust units 214 of the canard 206 have been assigned identification numbers 1.1 to 1.6. The six flaps or lift / thrust units 214 of the canard 208 have been assigned identification numbers 2.1 to 2.6. The twelve flaps or lift / thrust units 210 of the main wing 202 have been assigned identification numbers 3.1 to 3.12. The twelve flaps or lift / thrust units 212 of the main wing 204 have been assigned identification numbers 4.1 to 4.12.

[0105] The designations 1.1, 2.1, 3.1 and 4.1 respectively identify the innermost flaps or lift / thrust units adjacent to or close to the fuselage 203, and the designations 1.6, 2.6, 3.12 and 4.12 identify the outermost flaps or lift / thrust units at the greatest distance from the fuselage 203, while the other flaps or lift / thrust units and their positions along the corresponding wings or canards are indicated by Figure 3 The four identification numbers in the illustration are identified accordingly.

[0106] In both embodiments, the propulsion engines 232 or propulsion modules 230 arranged on the wings 202, 204, 206 and 208 and the flap actuators 240 associated with the four arrays of flaps 234 of the multiple flaps 210, 212, 214 and 216 are similar to Figure 1 Elements 14 , 16 , 18 and 20 of aircraft equipment are controlled by the flight control computer system 12 .

[0107] According to a preferred embodiment, all of these aircraft devices are electric aircraft devices that are powered by electricity provided by a plurality of batteries of the aircraft. The aircraft devices are electrical loads of the aircraft's electrical system, and the batteries are power sources of the aircraft's electrical system. The electrical system has an electrical power distribution network configured to connect electrical power sources to electrical loads, such that each electrical load or aircraft device can be driven by at least one associated power source or battery via at least one associated power channel of the electrical power distribution network. The present invention relates to an electrical power system for an aircraft and its electrical power distribution network, for example, such as in Figures 1 to 5 The illustrative embodiments are mentioned in the context of an electric power system and its electric power distribution network.

[0108] Figure 6 The power system 300 provided by the present invention is schematically shown. The power system has a plurality of power sources or batteries 302 (of which there are four in the schematic embodiment shown, denoted as power sources A, B, C and D), and a plurality of electrical loads 304 (of which there are five in this example, denoted as loads AA, BB, CC, DD1 and DD2), which are typically electric aircraft devices as described above. The power sources 302 and the electrical loads 304 are connected or connectable via a power distribution network 306. Figure 6 Each of the electrical loads may represent a plurality of electrical loads connected in parallel with the power distribution network 306, as shown by electrical loads DD1 and DD2, which together form an electrical load DD powered via the power distribution network.

[0109] According to conventional methods, the power distribution network 306 will be implemented as a separate network with independent power channels, such as Figure 7 As shown, the independent power channels are four independent power channels 308a, 308b, 308c, and 308d, each of which connects a specific one of the power sources to a specific one of the electrical loads. Each of the power channels is provided with a corresponding power link a, b, c, and d of a set of power links 310. The power links 310 are typically circuit protection arrangements, also known as "CPDs," that protect the downstream wiring and downstream loads of the corresponding power channel from damage in the event of a short circuit. For simplicity, the power links 310 will be referred to as "CPDs" hereinafter, but only in a non-limiting example sense. A skilled person can readily select a CPD that is appropriate for the wiring or power channel to be protected. CPDs having a typical trip time constant (e.g., on the order of approximately 10 ms) can be used, which is appropriate for the power channel and the specific environment of the specific power distribution network to be protected.

[0110] A separate network has the significant advantage of being fault resilient to a certain degree, as the power distribution network is separated into separate power channels 308 so that an electrical fault on one power channel will not affect another power channel. Figure 7 In the example shown, an electrical fault on load BB will cause a power outage on power channel 308b until CPDb isolates the fault. Other power channels are not affected.

[0111] The disadvantage of a separate network is that load sharing is impossible. If the loads are not equally powered, the demand for power will be inconsistent, causing the battery to discharge unevenly. This can limit the performance of electric aircraft.

[0112] Any alternative network that is unified rather than segmented is more suitable for load sharing. Figure 8 , which is schematically illustrated by the left-hand network portion formed by power channels 308a and 308b having a power source AB, electrical loads AA and BB, and CPDs a and b. The two power channels are connected by a connecting channel 312, thereby achieving load sharing across power sources A and B with respect to their associated electrical loads AA and BB. However, any electrical fault occurring on one of these power channels will also affect the other power channel and will propagate through the network, resulting in power interruption on all channels connected to the channel directly affected by the electrical fault until the fault is isolated.

[0113] Therefore, in the example shown, an electrical fault on load BB will cause power interruption of power channel 308b as well as power channel 308a, and even cannot be isolated because connecting channel 312 is arranged on the downstream side of CPDs a and b. Only when connecting channel 312 will connect power channels 308a and 308b on the upstream side of CPDs a and b, as shown in FIG. Figure 9 As shown, a hypothetical electrical fault on load D can be isolated by CPDb, so that load AA can thereafter be powered by power sources A and B.

[0114] A simultaneous loss of power to the entire power distribution network is typically unacceptable for safety / critical power distribution networks, such as those of aircraft.

[0115] There are three further disadvantages: i) because the electrical fault is supplied by both power sources A and B, more energy will be released, ii) because the electrical fault is supplied by both power sources A and B, if a CPD is provided on the downstream side of the connecting channel 312, the CPD must be interrupted at a higher fault current, iii) depending on the capacity of the network power supply and the reaction time of the CPD, other CPDs may also be mistakenly isolated, which will result in a loss of energy supply not only to load BB, but also to load AA, even though load AA is not faulty.

[0116] Figure 8 and Figure 9 Not only is a unified network shown, but also a switchable network, which is a hybrid solution used in today's conventional aerospace technology. Such a network uses switches to provide unification and separation, depending on the situation. Figure 8 and Figure 9 , power channels 308c and 308b are connected via a connecting channel 314, which includes a power link 316 in the form of a switch SW, which is located according to Figure 8 Downstream of CPD c and d and according to Figure 9 Upstream of CPDs c and d.

[0117] Because a fault occurring while switch SW is closed can propagate between power channels, the act of closing switch SW results in a significant reduction in safety. Therefore, according to conventional airspace technology, when the system is operating in a degraded mode, switch SW is closed only after a fault, thus failing to realize the benefits of unification during normal operation. An example of such an introduction of unification in response to a fault is a fault in source D, resulting in the isolation of power distribution network 306, causing load DD or loads DD1 and DD2 to no longer receive power from source D via power channel 308d. By closing power link 316 or switch SW, power can be supplied to these loads from source C, which must then drive loads CC and DD.

[0118] based on Figures 10 to 15 The illustrative, non-limiting network topology shown as an illustrative example in FIG, according to two alternative approaches proposed herein and denoted as "first approach" and "second approach", can achieve the main advantages of network segmentation and network unification in an advantageous and synergistic manner, as described below. In the following description, the following terminology is used: power channels 308 connecting respective power sources to respective electrical loads via respective power links similar to CPDs, i.e. Figure 10 The power channels 308a, 308b, 308c, and 308d are designated as "first-class power channels." These first-class power channels include a corresponding one of the aforementioned power links 310, i.e., one of the power links a, b, c, and d in the illustrated example, which are typically implemented as CPDs, as explained. These power links 310 are designated as "first-class power links." For simplicity, these power links will again be referred to as "CPDs" hereinafter, but only in a non-limiting example sense.

[0119] according to Figure 10 In the illustrative example of FIG, these power channels of the first category are connected to each other in pairs via connection channels 314, namely individual power channels 314a, 314b and 314c, each of which includes a corresponding power link ab, bc and cd of a group of power links 316. These connection channels 314 or 314a, 314b and 314c are denoted as "power channels of the second category", and their power links ab, bc and cd are denoted as "power links of the second category". According to Figure 10, power links 316 of the second type, denoted as ab, bc, and cd, are provided on the upstream side of the power links. Depending on the application and the method to be implemented, these power links of the second type can be CPDs, switches, SSPCs (Solid State Power Controllers), etc. Preferred embodiments according to the two proposed methods use SSPCs or switches as the power links of the second type. Therefore, hereinafter, for the sake of simplicity, these power links of the second type are denoted as "SSPC / SW" or "SSPCs / SWs" (SW stands for switch), but this is only for non-limiting example purposes.

[0120] Figure 11 An alternative configuration is shown where a second type of power channels or SSPCs / SWs 316 (ab, bc, cd) are located downstream of a first type of power links or CPDs a, b, c and d.

[0121] Alternatively, one or more SSPCs may be provided on the upstream side of the CPD of the associated power channel of the first type, and one or more power links of the second type may be provided on the downstream side of the first power link of the associated power channel of the first type, such as Figure 12 The second type of power channels 314a, 314b and their SSPCs / SWs ab and bc are located on the upstream side of CPDs a, b and c, while the second type of power channel 314c and its SSPC / SW cd are located on the downstream side of CPDs c and d. Figure 10 、 Figure 11 and Figure 12 The network topology achieves load sharing or partial load sharing across power sources A, B, C, and D with respect to electrical loads AA, BB, CC, and DD in the linear topology because the loads are connected or connectable via SSPCs / SWs ab, bc, cd included in a type of load sharing connection line formed by the second type of power channels 314a, 314b, and 314c.

[0122] Even more advantageously, the connection channels of the second type are connected with their SSPCs in a ring configuration so as to achieve load sharing or partial load sharing across the power sources A, B, C and D with respect to the electrical loads AA, BB, CC and DD in the ring topology, as shown in FIG. Figure 13 The connection between the first type of power channels 308c and 308d is as shown. Figure 13 The dotted line in FIG indicates that when load sharing or partial load sharing is performed via the load sharing connection loop formed by the second type of power channel, more power channels of the first type and their CPDs can be provided or included. The possibility of not providing the first type of power channel so that the second type of power channel 314c includes SSPC / SW cd is also possible. Figure 13 Shown in.

[0123] The annular passage is closed by a second type of power passage 314d having SSPC / SW ad connecting the first type of power passages 308a and 308d.

[0124] Another possibility is to connect the power channels of the first category in parallel with their SSPCs to form a star topology for load sharing or partial load sharing. Figure 14 A non-limiting example is shown. Here, power channel 308a of the first category is connected or connectable to each of the other illustrated power channels of the first category via a corresponding power channel of the second category, i.e., it is connected to power channel 308b of the first category via power channel 314a of the second category, it is connected to power channel 308c of the first category via power channel 314e of the second category, and it is connected to power channel 314f of the first category. Each of these power channels of the second category includes a respective SSPC / SW, designated ab, ac, and ad.

[0125] A disadvantage of the configuration shown is that a fault directly affecting the power channel 308a of the first category will also affect all other power channels of the first category and after isolating this fault, load sharing or partial load sharing is no longer possible.

[0126] Therefore, if Figure 15 The star load sharing configuration shown is preferred and does not use the first type of power channel as the hub or center of the star configuration, but instead uses a separate connecting channel 320 that is connected or connectable to each of the first type of power channels 308a, 308b, 308c and 308d via the second type of power channels 314g, 314h, 314i and 314j, each of which includes corresponding SSPC / SWax, bx, cx and dx.

[0127] All of these power distribution network configurations or topologies are merely non-limiting examples. All of these topologies can be implemented in combination in the respective network parts of the power distribution network, and other topologies known to the skilled person, such as mesh topologies and topologies known from US2020 / 0010187 A1, can also be implemented.

[0128] The configuration of the power distribution network and the operation of the power distribution network according to the mentioned preferred proposed method will now be described.

[0129] First method

[0130] According to the first approach mentioned, a unified power distribution network 306 is provided for normal operation, which can be switched to a separate or partially separate power distribution network in a very fast manner in the event of an electrical fault. To this end, the power link 316 of the second type is implemented as a very fast-acting solid-state switch or a very fast-acting solid-state CPD, or similarly or more preferably as a solid-state power controller (SSPC) or a load channel of one or more solid-state power controllers (SSPC) of the power distribution network.

[0131] These power links of the second category, preferably SSPCs, can be in a conductive state during normal operation and are therefore transparent with respect to load sharing. However, if an electrical fault is detected, these power links of the second category are configured to isolate very quickly, for example, within 10 to 20 μs, to introduce isolation. Hereinafter, as a non-limiting example, these power links of the second category will be referred to simply as "SSPCs." Generally, it is preferred that isolation times of approximately 100 μs, more preferably less than 100 μs, and most preferably approximately 10 to 20 μs, be achieved with SSPCs. However, slower isolation times, for example, approximately 1 ms, are not excluded.

[0132] An SSPC is a well-known electronic device that includes one or more conducting or load channels, a current measurement device for each load channel, and logic implemented in software or hardware to disconnect the load channel if a certain current threshold is exceeded, or possibly in response to one or more other trip conditions. Such current thresholds and trip conditions can be readily selected or defined by a skilled person based on the design of the power distribution network, the nature of the power source and electrical loads, and the maximum current values ​​and other electrical conditions expected for normal, trouble-free operation. The skilled person will consider appropriate safety factors.

[0133] Thereby, an electric power distribution network is realized which, on the one hand, utilizes the advantages of unification and benefits from load sharing, and, on the other hand, is also fault-tolerant and safe.

[0134] For example, consider Figure 10 and Figure 11 Power sources A and B, electrical loads AA and BB, first-type power channels 308a and 308b with CPDs a and b, and second-type power channel 314a with SSPC ab, which is inserted in parallel between power channels 308a and 308b. Under normal network operation, this SSPC is in a conducting state, so load AA can be equally powered by power sources A and B, and load BB can also be equally powered by power sources A and B. The same applies to the power supply having a power supply according to Figure 10 and Figure 11Other power channels of the first category and other power channels of the second category of SSPC, as well as other power channels according to Figures 12 to 15 This allows for load sharing in normal operation of the electricity distribution network, but isolates possible electrical faults in a very rapid manner by introducing appropriate separations.

[0135] Preferably, fault isolation is performed according to a plurality of subsequent fault isolation stages, preferably three fault isolation stages, because an electrical fault may have occurred that may have caused more SSPCs to switch from their conducting state to their non-conducting state than required for fault isolation.

[0136] The first fault isolation stage and the second fault isolation stage can again be explained and illustrated based on power sources A and B, electrical loads AA, BB, their associated power channels 308a and 308b of the first type with respective CPDs a and b, and associated power channels 314a of the second type with SSPCs a and b, for example according to Figure 10 and Figure 11 .

[0137] The first isolation stage results in the separation of this network portion into the first type of power channels. If an electrical fault occurs on load BB, SSPC ab will experience increased current due to power supply A feeding the fault and will be isolated very quickly by switching to its non-conducting state. The fault has now been isolated to power channel 308b, and power channel 308a can continue to operate normally. Load AA experiences little or no power interruption.

[0138] The electrical fault now affects only power channel 308b, allowing fault isolation within this channel according to the second fault isolation stage. Since the electrical fault affects only the first-class power channel 308b, the urgency of fault isolation is reduced. Since the electrical fault is powered solely by power source B, the energy released during the fault is minimal, and CPDb can safely interrupt the fault current. CPDb can safely isolate the fault, even in the form of a hypothetical short circuit.

[0139] A significant advantage of the proposed approach is that the conventional "selectivity" concept for coordinating multiple CPDs connected in series between a power source and a load so that the CPDs are isolated in the correct sequence is not relevant or utilized.

[0140] One or more SSPCs can be of any speed and do not require coordination with other SSPCs and CPDs, except that the second type of power link (preferably an SSPC) should be fast enough to allow the corresponding SSPC to trip before the first type of power link or CPD in the first type of power channel can trip. Providing a second type of very fast power link also helps limit the duration of the corresponding power interruption. The second type of power link or SSPC does not itself isolate power from the load, but only separates the first type of power channels from each other, so coordination of the second type of power link or SSPC is not as critical as with some CPDs on the network according to prior art methods.

[0141] The third fault isolation stage provides for the restoration of network unity, in addition to maintaining a certain separation required to isolate electrical faults. This fault isolation stage is relevant for larger networks with more power channels, such as in Figures 10 to 15 The cases shown are sources A and B and loads AA and BB are considered.

[0142] In such an extended power distribution network 306, it is likely that during the first fault isolation phase, multiple power links of the second category will switch to their non-conductive state. This is particularly true for SSPCs due to their high sensitivity. As a result, load sharing may be lost even between healthy power channels of the first category.

[0143] For example, it may happen that in Figure 10 and Figure 11 In network 306, SSPC cd between power channels 308c and 308d is switched to a non-conductive state. Although first-class power channel 308c is not affected by the electrical fault, first-class power channel 308b is affected. To isolate this electrical fault, only SSPCs ab and bc must be switched to a non-conductive state. Once first-class power channel 308c is isolated from faulty first-class power channel 308b by switching SSPC bc to a non-conductive state, SSPC cd can be switched back to a conductive state.

[0144] exist Figure 10 In the case of a network topology of , assuming that an electrical short circuit occurs in the electrical load BB, according to the second fault isolation stage, after the fault isolation within the power channel 308b of the first type (i.e., switching the CPDb of this power channel to its non-conductive state, which interrupts the fault current), even the other SSPCs ab and bc can return to the conductive state.

[0145] Considering the possibility of a fault occurring in the electric load, it seems advantageous to have the second-class power channel and its second-class power link or SSPC located upstream of the first-class power link or CPD. In such a case, according to the third fault isolation stage, after unified restoration, all power sources can continue to contribute to power supply and load sharing.

[0146] Considering the possibility that a power source may fail, it seems advantageous to have the second-class power channel and the second-class power channel or SSPC located downstream of the first-class power channel or CPD. In such a case, after restoration of unity according to the third fault isolation stage, power can continue to be supplied to all electrical loads based on load sharing across the remaining power sources.

[0147] Since both possibilities have their advantages, it is possible to use Figure 12 Hybrid configuration shown.

[0148] However, it is not excluded to provide a power channel of the second type with a corresponding power link of the second type on the upstream side and on the downstream side of the power link of the first type. In addition, it is possible to combine the first method proposed with a conventional hybrid method, i.e. to provide a fast-acting power link of the second type, in particular an SSPC, on one of the upstream and downstream sides and to provide a second type of fast-acting power link, in particular an SSPC, on the other of the upstream and downstream sides. Figure 8 and Figure 9 Conventional switches SW or power links 314 are shown which are in an open state during normal operation and are selectively switched to a conductive state during the third fault isolation phase.

[0149] The third fault isolation stage can be independently performed by each SSPC under the control of their respective logic devices based on the measured electrical conditions of their load channels. Alternatively, a centralized controller of the power distribution network can control the SSPCs to implement the third fault isolation stage, for example based on status data from the CPDs and SSPCs and possibly measured electrical conditions of the network.

[0150] The previous explanation of the three fault isolation phases applies similarly to Figures 10 to 15Other network topologies can be implemented. After completing the second fault isolation phase, all SSPCs between all first-category power channels, except for the faulty first-category power channel, can be reset to a conductive state to reintroduce load sharing and return the network to a near-normal operating state. Due to the achieved fault isolation, this operating state of the network can be represented as the network's electrical fault mitigation operating mode. Depending on the location of the SSPCs on the downstream or upstream side of the CPDs, it may even be possible for all SSPCs to be reset to a conductive state, as one or more CPDs achieving fault isolation within the corresponding first-category power channels may be sufficient for fault isolation.

[0151] For Figures 1 to 5 In the context of aircraft, and in general for so-called eVTOL applications, which employ multiple power sources and distributed electric propulsion units (EPUs) or lift / thrust units as electrical loads, it is advantageous to allocate the EPUs to the power channels in a symmetrical and distributed manner relative to the geometry of the aircraft, so that the loss of a power channel has minimal impact on vehicle controllability. This can be achieved by ensuring that a single power channel, in the case of the network configuration in question, provides well-distributed EPUs rather than adjacent EPUs.

[0152] Figure 16 In sub-figure a) the Figure 2 and Figure 3 A simplified schematic diagram of an aircraft having only six EPUs, namely EPU 1 and EPU 2 at the front wings or canards and EPU 3, EPU 4, EPU 5 and EPU 6 at the rear wings. Each of these EPUs may represent a unit comprising a plurality of propulsion engines.

[0153] Figure 16 Subfigure b) schematically illustrates an undesirable distribution because a fault on one power lane affects adjacent EPUs and affects asymmetric EPUs, where the line of symmetry is the vehicle's roll axis. Either EPUs 1, 3, and 4 are located on the right front and rear wings of the vehicle, or EPUs 2, 5, and 6 are affected. EPUs 1, 3, and 4 are located adjacent to each other on the right rear wing. EPUs 3 and 4 are located adjacent to each other on the right rear wing. EPUs 2, 5, and 6 are located on the left front and rear wings of the vehicle, and EPUs 5 and 6 are located adjacent to each other on the left rear wing.

[0154] Figure 16Subgraph c) of FIG2 schematically illustrates a distribution that is desirable because a failure on one power channel of the first category does not affect adjacent EPUs and provides better symmetry of failed EPUs (where the line of symmetry is the vehicle roll axis). If only one of power channels 308 a and 308 b fails, only one of the two EPUs 1 and 2 at the left and right front wings will be affected, and only one corresponding EPU on the left and right rear wings, namely EPUs 4 and 5 or EPUs 3 and 6, will be affected.

[0155] based on Figure 16 and Figure 16 The concept shown in sub-figure c) of can be similarly applied to Figure 2 and Figure 3 The EPU or lift / thrust unit or propulsion engine and flight actuators of the illustrated embodiment.

[0156] In general, the technician will be able to provide a sufficient number of common types of aircraft equipment, in particular lift / thrust units, and arrange these aircraft equipment in a suitable configuration on the aircraft, in particular on its wings, and distribute these aircraft equipment in a suitable manner to the power channels, in particular the first type of power channels of the power distribution network, so as to achieve the desired ability to withstand single or even multiple electrical failures.

[0157] For example, reference Figure 3 , an electrical failure may result in a simultaneous failure of the lift / thrust units 3.1 and 3.6 of the left main wing 202 or / and the lift / thrust units 4.1 and 4.6 of the right main wing 204. As a result, one or two lift / thrust units adjacent to the fuselage and one or two lift / thrust units still relatively close to the fuselage will be affected, thereby having no or minimal impact on the lateral balance.

[0158] For example, reference Figure 3 , an electrical failure may result in a simultaneous failure of the outermost lift / thrust unit 1.6 of the left canard 206 and the outermost lift / thrust unit 4.12 of the right main wing 204, or / and a simultaneous failure of the outermost lift / thrust unit 2.6 of the right canard 208 and the outermost lift / thrust unit 3.12 of the left main wing 202. Likewise, lateral balance will not be affected or will not be significantly affected.

[0159] The principle of the description of the ability to achieve resistance to failure based on the proposed method can of course also be applied to other Figure 2 、 Figure 3 and Figure 16The invention can be applied to aircraft of other types than the one shown in sub-figure a) of FIG, and can also be applied to completely different types of aircraft having such a number of lift / thrust units, propulsion engines, flaps, etc. that not all of these aircraft engines are required to maintain the flight capability and controllability of the aircraft. In order to achieve the ability to withstand single, double, or multiple electrical failures, when implementing the invention, a skilled person will be able to assign the various aircraft engines to the various power channels of the electrical power distribution network in such a way that the impact of such single, double, or multiple bus failures is minimized.

[0160] Second method

[0161] According to the second method mentioned above, a partially unified and partially separated power distribution network 306 is provided for normal operation of the power distribution network and, preferably, also for a fault mitigation mode of operation. According to this method, the network switches sequentially between a plurality of different partial load sharing configurations, each of which is associated with a respective one of a plurality of partial load sharing modes. The power distribution network sequentially adopts these partial load sharing modes, and thus its partial load sharing configurations, in a time-varying manner. Each of these different partial load sharing configurations corresponds to a different type of partial unification and partial separation of the network. This sequential, preferably periodic, switching between the partial load sharing configurations enables uniform discharge of the power supply.

[0162] This switching between the different part-load sharing configurations is effected by the second type of power links 316, which switch between their conductive state and their non-conductive state in a synchronized manner, preferably relatively slowly compared to the tripping time of a typical circuit protection arrangement or CPD, and even slower than the typical tripping time of a solid-state power controller (SSPC). For example, a suitable time range for switching of the second type of power links 316 may be switching between the conductive state and the non-conductive state at intervals of one minute. Thus, relatively slow electromechanical or solid-state switches are suitable for implementing the second type of power links 316, although other components that allow switching between the conductive state and the non-conductive state may also be used.

[0163] In the following, these power links of the second category are referred to simply as "SW" or "SWs" to represent one or more suitable switches, but only as non-limiting examples.

[0164] Furthermore, as is the case according to the proposed first approach described above, the power links of the first class may be suitable circuit protection arrangements or “CPDs.” In the following, these power links of the first class are referred to simply as “CPDs,” again as a non-limiting example only.

[0165] based on Figure 13 The ring topology of FIG. 1 illustrates load sharing across power supply sections in a time-varying manner with respect to associated electrical loads according to a plurality of different partial load sharing modes sequentially employed by the power distribution network. Now, assume that first-class power channel 308c and first-class power channel 308d are directly connected via second-class power channel 314c, which has a switch SW as second-class power link cd. Accordingly, the other second-class power links ad, ab, and bc are also switches, while power links a, b, c, and d are CPDs.

[0166] Suitable partial load sharing modes for phase 1 and phase 2 are as follows, for example:

[0167] stage Closed switch Open switch Power supply for load sharing 1 ab、cd bc、ad A and B, C and D 2 bc、ad ab、cd B and C, A and D

[0168] By periodically alternating between phases 1 and 2 during operation, it is ensured that an electrical fault never affects more than half of the channels. According to the two phases 1 and 2, each phase has associated the power sources A, B, C and D and the corresponding electrical loads AA, BB, CC and DD with a plurality of separate load-sharing groups, i.e., in phase 1 with separate partial load-sharing groups (A+B, AA+BB) and separate partial load-sharing groups (C+D, CC+DD), and in phase 2 with partially separate load-sharing groups (B+C, BB+CC) and partially separate load-sharing groups (A+D, AA+DD). These groups of the respective phases are denoted as "separate groups" because they have no common elements.

[0169] All power supplies have the opportunity to load share with other power supplies, either directly or via another source (if provided).

[0170] This solution is scalable to any number of power channels.

[0171] It is also possible to distribute power and loads to different phases, for example as shown below:

[0172] stage Closed switch Open switch Power supply for load sharing 1 ab bc、cd、ad A and B 2 bc ab、cd、ad B and C 3 cd bc, bc, ad C and D 4 ad ab、bc、cd A and D

[0173] According to this example, each stage has allocated power and load to the corresponding common partial load sharing group, that is, to the common load sharing group (A+B, AA+BB) in stage 1, to the common load sharing group (B+C, BB+CC) in stage 2, to the common load sharing group (C+D, CC+DD) in stage 3, and to the common load sharing group (A+D, AA+DD) in stage 4.

[0174] However, no particular advantage is obtained compared to the first example.

[0175] If the network criticality allows the loss of more than half of the channels at a certain point in time, an additional phase becomes possible, in which the three power channels of the first category participate in load sharing simultaneously, for example as follows:

[0176] stage Closed switch Open switch Power supply for load sharing 1 ab、bc cd、ad A vs. B vs. C 2 bc、cd ab、ad B vs. C vs. D 3 cd、ad ab、bc A vs. C vs. D 4 ab、ad bc、cd A vs. B vs. D

[0177] According to this example, each stage again allocates power and load to the corresponding common partial load sharing group, i.e., to the common load sharing group (A+B+C, AA+BB+CC) in stage 1, to the common load sharing group (B+C+D, BB+CC+DD) in stage 2, to the common load sharing group (A+C+D, AA+CC+DD) in stage 3, and to the common load sharing group (A+B+D, AA+BB+DD) in stage 4.

[0178] In case of an electrical fault, the corresponding power channels of the first category will be excluded from further part load sharing for isolating the electrical fault.However, part load sharing according to a plurality of different part load sharing modes sequentially adopted by the network may continue.

[0179] Assuming that there is an electrical failure in the source C or the load CC, the network may periodically adopt, for example, the following phases:

[0180] stage Closed switch Open switch Power supply for load sharing 1 ab bc、cd、ad A and B 2 ad ab、bc、cd A and D

[0181] These phases 1′ and 2′ corresponding to phases 1 and 4 of the second example above correspond to a partial fault isolation load sharing mode of the power distribution network. These phases are a subset of phases 1 to 4 of the second example above, phase 1′ corresponding to phase 1 and phase 1′ corresponding to phase 4.

[0182] Alternatively, if the electrical fault must be isolated, a permanent load sharing can be implemented across all sources of the healthy power channels of the first class in the electrical fault mitigation operating mode of the power distribution network for the load of the power sources of the healthy power channels of the first class. In this example, assuming again that the power source C or the load CC has an electrical fault, the network can employ the following fault mitigation phases to permanently isolate the fault until the electrical fault is resolved:

[0183] stage Closed switch Open switch Power supply for load sharing 1 ab、ad bc、cd A vs. B vs. D

[0184] Based on Figure 15 Another example is given by the star topology of FIG. The power links ax, bx, cx, and dx between the connection channel 320 acting as the central node and each power channel of the first class are again assumed to be switches. Examples of suitable partial load sharing modes or phases are the following phases 1 to 6:

[0185] stage Closed switch Open switch Power supply for load sharing 1 ax, bx cx、dx A and B 2 ax、cx bx、dx A and C 3 ax、dx bx、cx A and D 4 bx、cx ax、dx B and C 5 bx、dx ax、dx B and D 6 cx、dx ax, bx C and D

[0186] As with the other examples, this solution can be extended to any number of power channels, and the transitions between the phases can be made in any order. If the network criticality allows the loss of more than half of the channels, additional phases become possible, where, for example, three channels instead of just two participate in the corresponding simultaneous partial load sharing.

[0187] In the event of a failure of the power channel 308c due to a failure of the source C or the load CC, the following phases may be periodically assumed in the electrical fault mitigation operating mode of the network:

[0188] stage Closed switch Open switch Power supply for load sharing 1 ax, bx cx、dx A and B 2 ax、dx bx、cx A and D 3 bx、dx ax、dx B and D

[0189] These phases 1 ′, 2 ′ and 3 ′ are a subset of phases 1 to 6 of the example given for normal operation, phase 1 ′ corresponding to phase 1 , phase 2 ′ corresponding to phase 3 , and phase 3 ′ corresponding to phase 5 thereof.

[0190] Alternatively, if necessary, the load for the power sources of the healthy power channels of the first category may again be permanently load-shared across the power sources of the healthy power channels of the first category in the electrical fault mitigation operating mode of the power distribution network.

[0191] The transition between the various phases or partial load sharing modes of the respective embodiments is preferably accomplished by first opening the currently closed switch and then closing the switch to be closed to implement the next phase. This ensures that the phase transition does not involve any reduction in the safety factor. Therefore, switching between phases is preferably not performed directly, but only after an intermediate phase without partial load sharing across sources.

[0192] As reference Figure 16 and Figure 3 The considered and explained loads that are critical can be distributed in a suitable and symmetrical manner to the power channels of the first category and to the wings and fuselage of the aircraft in order to achieve resistance and maintain the controllability of the aircraft. This also applies in the context of the second approach proposed.

[0193] Advantageously, the various partially common or partially separate load-sharing groups of the partial load-sharing mode or partial load-sharing phase are formed in such a way that the respective loads or aircraft equipment of critical importance of each respective common or separate load-sharing group are well distributed in a symmetrical manner over the wings and / or fuselage of the aircraft, so that a failure of one of these groups is not critical and does not impair the controllability of the aircraft. In this case, it is not very important for the power distribution network to notice the occurrence of an electrical fault and to react to it very quickly in order to isolate the electrical fault and adopt an electrical fault mitigation operating mode.

[0194] A person skilled in the art has many possibilities for implementing the proposed concepts and methods of this disclosure in detail. A person skilled in the art may also decide to implement both proposed methods simultaneously in an aircraft's power distribution network, for example by applying one of these methods to one network section and the other method to another network section. Furthermore, if the power links of the second type are appropriately selected, the power distribution network can, in principle, be configured or configurable to comply with both methods.

[0195] It should be noted that the terms used above, such as "power source", "electric load", "power channel", "power channel of the first category", "power channel of the second category", "power link", "power link of the first category" and "power link of the second category" are essentially general terms that deal with specific functions in a specific technical context and do not necessarily imply specific structures and specific elements for implementing these functions. Therefore, it is possible to integrate multiple power links in one corresponding power network device. Even one or more power links of the first category and one or more power links of the second category can be integrated in one corresponding power network device. Such power links integrated in the power network device can share the connection port of the power network device, for example, so that one connection port of the power network device is simultaneously a connection port of the power link of the first category and a connection port of the power link of the second category. In this sense, such a power network device can also include a power channel or a power channel part integrated into the device, as well as a corresponding power link.

[0196] A power distribution network (306) of an electrical power system (300) of an aircraft is operated so that it sequentially adopts a plurality of different partial load sharing modes in a time-varying manner, the partial load sharing modes providing partial load sharing across power sources (A, B, C, D) for associated electrical loads (AA, BB, CC, DD) by sequentially switching between a plurality of different partial load sharing configurations of the power distribution network, each partial load sharing configuration being associated with a particular one of the partial load sharing modes.

[0197] Reference numerals

[0198] 10 Flight Control System

[0199] 12 Flight Control Computer System

[0200] 12a, 12b, 12c flight control computers

[0201] 14, 16, 18, 20 Aircraft equipment

[0202] 22 Control bus system

[0203] 30a, 30b Left and right side rod devices

[0204] 32a, 32b Left and right side bars

[0205] 38a, 38b sensor assembly

[0206] 42a, 42b connection link

[0207] 200 canard-wing aircraft

[0208] 202 Left rear wing

[0209] 203 fuselage

[0210] 204 Right rear wing

[0211] 206 Left front wing

[0212] 208 right front wing

[0213] 210, 212, 214, 216; 234 flaps

[0214] 230 Propulsion Module

[0215] 232, 232a, 232b, 232c propulsion engines

[0216] 3.1 to 3.12 Lift / thrust unit on the left rear wing

[0217] 4.1 to 4.12 Lift / thrust unit on right rear wing

[0218] 1.1 to 1.6 Lift / thrust unit on the left front wing

[0219] 2.1 to 2.6 Lift / thrust unit on the right front wing

[0220] 236 Wing

[0221] 240 flap actuator

[0222] 242 pivot joint

[0223] 300 Power System

[0224] 302; A, B, C, D power supply

[0225] 304; AA, BB, CC, DD1, DD2, DD electrical load

[0226] 306 Electricity Distribution Network

[0227] 308; 308a; 308b; 308c; 308d Power channel; First type of power channel

[0228] 310; a, b, c, d Type I power train

[0229] 312, 314 power channels

[0230] 316; SW power link; switch

[0231] 314; 314a, 314b, 314c, 314d, 314e, 314f, the second type of power channel

[0232] 314g, 314h, 314i, 314j

[0233] 316; ab, bc, cd, ad, ac, ad, ax, bx, cx, the second type of power link

[0234] dx

[0235] 312, 314, 314a, 320 connecting channels

[0236] EPU1, EPU2, EPU3, EPU4, EPU5, EPU6 electric propulsion units.

Claims

1. A power system (300) for an aircraft (200), comprising a plurality of electrical loads (304), a plurality of power sources (302), and a power distribution network (306), the power distribution network (306) being configured to connect the power sources with the electrical loads such that each electrical load can be driven by at least one associated power source via at least one associated power channel (308) of the power distribution network; wherein the power distribution network (306) includes at least one of a circuit protection arrangement and a circuit switching arrangement having a plurality of switchable or interruptable power links (310, 316), wherein each power link has two connection ports, and wherein each power link is configured to connect the connection ports in a first operating mode for transmitting power from a driving power channel or a driving power channel portion connected to one of the connection ports to a driven power channel or a driven power channel portion connected to the other of the connection ports, and wherein each power link is configured to interrupt the connection between the connection ports in a second operating mode for preventing power transmission between the driving power channel or the driving power channel portion and the driven power channel or the driven power channel portion; It is characterized by: the power distribution network (306) being configured to provide partial load sharing across power sources (A, B; C, D; B, C; A, D; A, B; A, C; A, D; B, C; B, D; C, D) in a time-varying manner with respect to a plurality of associated electric loads (AA, BB; CC, DD; BB, CC; AA, DD; AA, BB; AA, CC; AA, DD; BB, CC; BB, DD; CC, DD) by sequentially switching between a plurality of different partial load sharing configurations of the power distribution network in accordance with a plurality of different partial load sharing modes sequentially adopted by the power distribution network (306), each partial load sharing configuration being associated with a particular one of the partial load sharing modes; and wherein the power distribution network is configured such that each power source in at least one group of the plurality of power sources is associated with at least one of the different partial load sharing modes, and each electric load in at least one group of the plurality of electric loads is associated with at least one of the different partial load sharing modes, and the power distribution network is configured such that each partial load sharing mode has associated multiple power sources and multiple electric loads, so that the power sources and electric loads form a common load sharing group or multiple separate load sharing groups for the corresponding partial load sharing mode, wherein the power distribution network (306) when adopting the corresponding partial load sharing mode provides load sharing across the power sources of the associated common load sharing group with respect to the electric loads of the associated common load sharing group, or provides respective partial load sharing for each of the separate load sharing groups, which is load sharing across the power sources of each corresponding separate load sharing group with respect to the electric loads of this corresponding separate load sharing group, rather than any load sharing across the separate load sharing groups.

2. The power system of claim 1 , wherein the power distribution network is configured such that each power source in at least one group of the plurality of power sources is associated with at least two of the different partial load sharing modes, and each electric load in at least one group of the plurality of electric loads is associated with at least two of the different partial load sharing modes.

3. The power system of claim 1 , wherein the power distribution network ( 306 ) is configured to operate in at least one normal operating mode and at least one electrical fault mitigation operating mode, wherein the power distribution network is configured to sequentially employ the different partial load sharing modes in the normal operating mode.

4. The power system according to claim 3, wherein the power distribution network (306) provides electrical fault isolation in the electrical fault mitigation operating mode, so that the network portion of the power distribution network including the electrical fault is isolated from at least one other network portion of the power distribution network by at least one power channel (314) adopting the second operating mode.

5. An electric power system according to any one of claims 1 to 4, wherein the electric power distribution network is configured to provide partial load sharing across all power sources (A, B, C, D) with respect to all electric loads (AA, BB, CC, DD) according to the plurality of different partial load sharing modes employed in sequence.

6. The power system of claim 1, wherein the power distribution network (306) includes a plurality of power channels (308) of a first type; Wherein each power channel of the first category has been associated with at least one associated power source (A; B; C; D), at least one associated power source (A; B; C; D) is not associated with another power channel of the first category, and wherein each power channel of the first category has been associated with at least one electric load (AA; BB; CC; DD), at least one electric load (AA; BB; CC; DD) is not associated with another power channel of the first category, so that at least one associated power source is connected or can be connected to at least one associated electric load via the corresponding power channel of the first category, so that the at least one power source can drive the at least one electric load via the corresponding power channel of the first category without having to involve driving via another power channel of the first category.

7. An electric power system according to claim 6, wherein a plurality of power channels (308) of a first class are connected or connectable via a connecting channel arrangement of the electric power distribution network, the connecting channel arrangement comprising one or more power channels (314) of a second class for transferring power between these power channels of the first class via at least one power channel of the second class, thereby achieving partial load sharing across power sources (A, B, C, D) associated with at least one group of power channels of the first class or associated with all power channels of the first class with respect to electrical loads (AA, BB, CC, DD) associated with these power channels of the first class.

8. An electric power system according to claim 6 or 7, wherein each of the power channels (308) of the first class includes a power link (310) of the first class, which allows the transmission of electric power from the associated at least one power source (A; B; C; D) to the associated at least one electric load (AA; BB; CC; DD) via this power link of the first class in its first operating mode, and prohibits the transmission of electric power from the associated at least one power source to the associated at least one electric load via this power link of the first class in its second operating mode; wherein each power link of the first class is configured to change its operating mode from the first operating mode to the second operating mode in response to at least one preset or presettable electrical tripping condition indicating an electrical fault.

9. An electric power system according to claim 7, wherein each of the second-class power channels (314) includes a second-class power link (316), the second-class power link (316) allowing power to be transmitted between the first-class power links (310) via this second-class power link in its first operating mode, and the second-class power link (316) prohibiting power to be transmitted between the first-class power links (310) via this second-class power link in its second operating mode; wherein each second-class power link is provided by an associated electromechanical or solid-state circuit switching device of the power distribution network.

10. A method for operating an electrical system (300) of an aircraft (200), the electrical system (300) comprising a plurality of electrical loads (304), a plurality of power sources (302), and a power distribution network (306), the power distribution network (306) being configured to connect the power sources with the electrical loads so that each electrical load can be driven by at least one associated power source via at least one associated power channel of the power distribution network; wherein the power distribution network (306) comprises a plurality of switchable or interruptible power links (310, 316), each power link being arranged within a respective power channel of the power distribution network for enabling power transmission via the respective power channel in a first operating mode of the power link and for preventing power transmission via the respective power channel in a second operating mode of the power link; It is characterized by: The method comprises operating the power distribution network (306) such that the power distribution network sequentially adopts a plurality of different partial load sharing modes in a time-varying manner, which provides partial load sharing across power sources (A, B; C, D; B, C; A, D; A, B; A, C; A, D; B, C; B, D; C, D) with respect to a plurality of electric loads of associated electric loads (AA, BB; CC, DD; BB, CC; AA, DD; AA, BB; AA, CC; AA, DD; BB, CC; BB, DD; CC, DD) by sequentially switching between a plurality of different partial load sharing configurations of the power distribution network, each partial load sharing configuration being associated with a particular one of the partial load sharing modes; wherein each power supply in at least one group of the plurality of power supplies is associated with at least one of a different partial load sharing mode, and each electric load in at least one group of the plurality of electric loads is associated with at least one of a different partial load sharing mode, and each partial load sharing mode has associated multiple power supplies and multiple electric loads, so that the power supplies and the electric loads form a common load sharing group or multiple separate load sharing groups of the corresponding partial load sharing mode, wherein the power distribution network (306) provides load sharing across the power supplies of the associated common load sharing group with respect to the electric loads of the associated common load sharing group when it operates in the corresponding partial load sharing mode, or provides respective partial load sharing for each of the separate load sharing groups, which is load sharing across the power supplies of each corresponding separate load sharing group with respect to the electric loads of this corresponding separate load sharing group, rather than any load sharing across the separate load sharing groups.

11. A method according to claim 10, wherein each power supply in at least one group of the plurality of power supplies is associated with at least two of the different partial load sharing modes, and each electric load in at least one group of the plurality of electric loads is associated with at least two of the different partial load sharing modes.

12. The method of claim 11, wherein the method comprises operating the power distribution network (306) in at least one normal operating mode that provides partial load sharing across power sources with respect to associated electrical loads by sequentially switching between a plurality of different partial load sharing configurations of the power distribution network; and The method includes operating the power distribution network (306) in at least one electrical fault mitigation operating mode that provides electrical fault isolation such that a network portion of the power distribution network comprising the electrical fault is isolated from at least one other network portion of the power distribution network by at least one power link adopting the second operating mode.

13. The method according to any one of claims 10 to 12, wherein the power distribution network (306) includes power channels (308) of a first type, each power channel of the first type including a corresponding power link (310) of the first type, and wherein the power distribution network (306) includes one or more power channels (314) of a second type, each power channel of the second type including a corresponding power link (316) of the second type; wherein each power channel of the first category connects at least one associated power source (302) to at least one associated electrical load (304) for enabling the at least one associated power source to drive the at least one associated electrical load without involving driving via another power channel of the first category; and wherein each power channel (314) of the second category is connected or connectable to at least two associated power links (310) of the first category for enabling power to be transferred between the power channels of the first category so as to enable partial load sharing across the power sources (A, B, C, D) associated with these power channels of the first category with respect to the electrical loads (AA, BB, CC, DD) associated with these power channels of the first category; The method involves repeatedly switching a power channel of the second type (314) between its first operating mode and its second operating mode such that the power distribution network switches sequentially between a plurality of different partial load sharing configurations or between a plurality of different partial fault isolation load sharing configurations.

14. An aircraft (200), comprising the power system (300) according to any one of claims 1 to 9; wherein the aircraft (200) is at least one of a single-pilot aircraft, an aircraft with vertical takeoff and landing capabilities, and a canard-type aircraft.

15. An aircraft according to claim 14, wherein the power system (300) includes at least one group of common type of electrical loads in the form of aircraft equipment, which electrical loads are essential for maintaining safe flight operation of the aircraft, wherein the aircraft equipment is arranged in a certain number and configuration at one or both of the fuselage (203) of the aircraft and the wings (202, 204, 206, 208) of the aircraft to achieve fault resistance, so that each subgroup of multiple aircraft equipment can fail without endangering the flight capability and controllability of the aircraft, each subgroup of multiple aircraft equipment includes at least two common types of aircraft equipment.

16. An aircraft according to claim 15, wherein the aircraft equipment or each corresponding subgroup of aircraft equipment is associated with a specific power channel of the power distribution network of the power system (300) for being driven together via this power channel, and wherein the aircraft equipment or each corresponding subgroup of aircraft equipment is arranged in a symmetrically distributed manner on one or both of the fuselage (203) of the aircraft and the wings (202, 204, 206, 208) of the aircraft, so that an electrical fault that directly or indirectly affects the power channel and causes a fault of the aircraft equipment of this subgroup does not endanger the flight capability and controllability of the aircraft.

17. An aircraft according to claim 15 or 16, wherein each of the aircraft devices is associated with at least one or more of the different partial load sharing modes, such that the aircraft devices form one common load sharing group or a plurality of separate load sharing groups of the corresponding partial load sharing modes; The aircraft equipment is associated with different partial load sharing modes so as to form a corresponding common load sharing group or corresponding multiple separate load sharing groups in such a manner, and, for each of the different partial load sharing modes, the aircraft equipment of the common load sharing group or each of the multiple separate load sharing groups is arranged to be symmetrically distributed on the fuselage (203) of the aircraft and one or both of the wings (202, 204, 206, 208) of the aircraft in such a manner that an electrical fault that directly or indirectly affects the aircraft equipment of the corresponding common load sharing group or the corresponding separate load sharing group and causes a fault of its aircraft equipment does not endanger the flight capability and controllability of the aircraft.

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