Electrical fault isolation in aircraft power distribution networks

Abstract

An electrical power distribution network (306) of an electrical power system (300) of an aircraft is operated in at least one normal operating mode such that it provides load sharing across power sources (A, B, C, D) with respect to electrical loads (AA, BB, CC, DD), wherein in the event of an electrical fault the electrical power distribution network (306) is operated in at least one electrical fault mitigation operating mode such that electrical fault isolation is provided such that a network portion of the electrical power distribution network (306) comprising the electrical fault is isolated from at least one other network portion of the electrical power distribution network.

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 devices (CPDs), 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-presettable (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, it is an object of the present invention to provide an electrical power system for an aircraft and a corresponding operating method which allow achieving a substantial resilience against electrical faults 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 present invention is to provide an electrical power system for an aircraft and a corresponding operating method which allow a uniform discharge of the power source in the form of batteries or battery cells. 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 electric power distribution network is configured to operate in at least one normal operating mode and at least one electrical fault mitigation operating mode.

[0021] The power distribution network provides load sharing across power sources in a normal operating mode, such that at least one group of the multiple power sources jointly drives at least one associated group of the multiple electric loads via a power channel or power channel portion associated therewith and at least one power link associated therewith and in a first operating mode.

[0022] The power distribution network provides electrical fault isolation in the electrical fault mitigation mode 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.

[0023] The proposed power distribution system combines the advantages of a unified and separate electrical network. In the normal operating mode, adopted during normal flight operations of the aircraft, the unification of the network's power channels allows for effective load sharing between the power sources. In the event of an electrical fault, the power distribution network adopts an electrical fault mitigation operating mode that provides isolation between the relevant power channels and, therefore, the electrical fault.

[0024] According to the invention, for the normal operation of the aircraft, a unified electrical network can be achieved, with all the advantages resulting from this unification, although according to conventional approaches such unification is considered unsafe for safety-critical applications like aviation.

[0025] Thus, the power system of the present invention differs significantly from conventional aircraft power distribution networks, which, during normal aircraft operation, irrevocably assign specific electrical loads to specific power sources through the use of separate power paths. 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.

[0026] According to the present invention, a completely different approach is pursued. In normal operation, multiple or all power supplies and multiple or all electrical loads are unified or connected together, which is optimal for load sharing across the power supplies and thereby uniform power demand on the power supplies. The batteries used as power supplies are discharged uniformly. 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. This electrical fault isolation can be accomplished in an extremely rapid manner by using appropriate technical components, such as solid state power controllers (SSPCs), which can be used as a first stage fast-acting isolation according to the present invention, the purpose of which is not to isolate the fault source or the faulty load, but to introduce separation in a purposeful manner for mitigating the electrical fault.

[0027] Fault isolation through purposeful separation allows for easier and faster fault elimination compared to a standard unified network, as it is easier to eliminate a fault in a separated or partially separated power distribution network when only one or a limited number of power sources are supplying the fault, as opposed to the case of many power sources in a standard unified network.

[0028] The power distribution network may be 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, such that a plurality of groups of power sources of the plurality of power sources and a plurality of associated groups of electrical loads of the plurality of electrical loads are provided, wherein the respective one or more groups of power sources activated at a certain point in time to jointly drive at least one group of associated electrical loads varies sequentially, preferably periodically. However, in the context of the present disclosure, permanent continuous load sharing across the power sources in normal operating mode is more preferred.

[0029] Advantageously, the power distribution network can be configured to adopt an electrical fault mitigation operating mode so that an electrical fault occurring at one of the group of power supplies can be isolated from at least one other power supply in the group of power supplies and at least one electrical load in the group of electrical loads, and so that an electrical fault occurring at the group of electrical loads can be isolated from at least one power supply in the group of power supplies and at least one other electrical load in the group of electrical loads, so that at least one power supply that is not affected by the electrical fault and belongs to the group of power supplies can drive at least one electrical load that is not affected by the electrical fault and belongs to the group of electrical loads; wherein the isolation of the electrical fault is achieved by at least one power link that changes its operating mode from a first operating mode to a second operating mode.

[0030] If desired, a plurality of electrical loads of the same type may form a group of electrical loads. Alternatively, a plurality of electrical loads of different types may form a group of electrical loads. A plurality of different groups of this type may be provided.

[0031] According to a preferred embodiment, the power distribution network is configured to provide load sharing across all power sources in a normal operating mode, so that all of the multiple power sources jointly drive all of the multiple electrical loads via corresponding power channels or power channel portions and corresponding power links that adopt a first operating mode; wherein the power distribution network is configured to adopt an electrical fault mitigation operating mode in such a manner that an electrical fault occurring at a power source or an electrical load can be isolated, so that multiple or all power sources that are not affected by the electrical fault can drive multiple or all electrical loads that are not affected by the electrical fault.

[0032] 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.

[0033] Unification between a plurality of power channels of the first category can be achieved by providing a power channel of another category in addition to the power channels of the first category. In view of this, 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 electric 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.

[0034] 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.

[0035] 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 channels of the second type, for transmitting power between the two power channels of the first type via the power channels of the second type, so that load sharing across the power sources associated with the two power channels of the first type can be achieved with respect to the electrical loads associated with the two power channels of the first type. In this regard, it is preferred that power transmission between the two power channels of the first type via the power channels of the second type does not necessarily involve power transmission via another power channel of the second type.

[0036] 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.

[0037] 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 load sharing across electrical loads in a ring topology.

[0038] 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 or are connected or connectable to each other via a corresponding power channel of the second type, wherein, if one or more such other power channels are provided, each other power channel of the plurality of power channels of the first type or of the subgroup of the plurality of power channels of the first type is connected or connectable to two other 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 via a corresponding power channel of the second type, so that load sharing across the electrical loads is achieved in a linear topology along all these power channels of the second type. This also includes the case where only two power channels of the first type are provided, which are connected or connectable to each other via a power channel of the second type.

[0039] 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 load sharing across the electrical load in a star topology. If desired, each of these at least three other power channels can be the starting power channel of a power channel circuit comprising the plurality of power channels according to the linear topology.

[0040] 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 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 linear topology.

[0041] 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.

[0042] 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.

[0043] 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 within a tripping time interval of a first order of magnitude in response to at least one preset or presettable electrical trip condition indicative of an electrical fault.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] In order to realize that the power distribution network can adopt a configuration that provides partial unity and a configuration that provides 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.

[0048] Each power link of the second class can be configured to change its operating mode from the first operating mode to the second operating mode within a tripping time interval of the second order of magnitude in response to at least one preset or preset electrical tripping condition indicative of an electrical fault. In order to allow the power distribution network to react quickly enough to the electrical fault to introduce the separation required for fault isolation, it is proposed that the tripping time interval of the first order of magnitude of the power links of the first class significantly exceeds the tripping time interval of the second order of magnitude of the power links of the second class. As a result, it is possible that only one or more power links of the second class trip and switch to the second operating mode, but no power links of the first class were present during the time interval before the one or more power links of the second class tripped. Only at a later time, after fault isolation has been achieved, will typically only a specific power link of the first class trip, which is still affected by the electrical fault after separation or partial separation.

[0049] Various suitable electrical trip conditions known in the art can be achieved by corresponding configuration of one or more power links of the second type. In this regard, it is proposed that at least one predetermined electrical trip condition includes at least one of the following: i) a current transmitted via the power link of the second type and exceeding a predetermined current trip threshold, ii) an i2t amount representing electrical energy consumed via the power link of the second type within a predetermined reference time interval and exceeding a predetermined electrical i2t trip threshold; and iii) thermal energy determined by a controller of the power distribution network based on a thermal model to have accumulated in an associated component of the power system within a predetermined reference time interval and exceeding a predetermined thermal energy trip threshold.

[0050] To be sufficiently fast, each power link of the second category should typically be protected by an associated solid-state circuit protection device of the power distribution network, such as a solid-state circuit breaker. Thus, sufficiently fast conventional solid-state circuit breakers can be used to implement the present invention with respect to the power links of the second category, which provide for separation between the power channels of the first category before any of the power links of the first category trip and transition to their second operating mode.

[0051] However, according to a particularly preferred approach, each power link of the second category is provided by an associated solid-state power controller of the power distribution network, the solid-state power controller comprising a microcontroller, at least one load channel forming the power link of the second category, and at least one solid-state switch included in the load channel and operable under control of the microcontroller, wherein the microcontroller is configured to switch the solid-state switch between a conducting state corresponding to a first operating mode of the power link of the second category and a non-conducting state corresponding to a second operating mode of the power link of the second category, and the microcontroller is configured to monitor at least one current electrical condition of the load channel for responding to the occurrence of an electrical trip condition by switching the solid-state switch from a conducting state to a non-conducting state. By implementing the power links of the second category using one or more solid-state power controllers, a number of advantages are achieved.

[0052] According to a particularly preferred embodiment that can be implemented in a particularly advantageous manner by using a solid-state power controller as a power link, the power distribution network is configured to provide electrical fault isolation by subsequently taking at least three fault isolation stages when switching from a normal operating mode to an electrical fault mitigation mode in response to the occurrence of an electrical fault; wherein the first fault isolation stage provides separation of power channels from each other by at least one power link switching from its first operating mode to its second operating mode; wherein the subsequent second fault isolation stage provides fault isolation within power channels still affected by the electrical fault by the power link switching from its first operating mode to its second operating mode; and wherein the subsequent third fault isolation stage provides partial restoration of load sharing across power sources not affected by the electrical fault with respect to electrical loads not affected by the electrical fault by at least one power link switching from its second operating mode to its first operating mode, and is isolated from the electrical fault by at least one other power link taking the second operating mode.

[0053] The first fault isolation phase can advantageously provide separation of the power channels of the first class from one another by at least one power link of the second class, which is included in the corresponding power channel of the second class and switches from its first operating mode to its second operating mode.

[0054] The second fault isolation stage can advantageously provide fault isolation within the first class power channel by a first class power link included in this first class power channel, which first class power link switches from its first operating mode to its second operating mode.

[0055] The third fault isolation stage can advantageously provide partial restoration of load sharing across power sources not affected by the electrical fault with respect to electrical loads not affected by the electrical fault by at least one power link of the second class, at least one power link of the second class being included in a corresponding power channel of the second class and switching from its second operating mode to its first operating mode, and being isolated from the electrical fault by at least one other power link continuing to adopt the second operating mode.

[0056] The third fault isolation stage is particularly useful because multiple power links of the second category may have tripped and switched to the second operating mode, while one or more power links are not directly connected to the location of the electrical fault, but only via one or more other power links of the second category. After achieving fault isolation, such power links of the second category can be switched back to their first operating mode to reintroduce partial unification, thereby partially restoring load sharing across the power sources.

[0057] Therefore, the at least one other power link that continues to adopt the second operating mode and isolates one or more power links of the second category from the electrical fault may include at least one power link of the second category included in the corresponding power channel of the second category. However, it is also possible that the at least one other power link that continues to adopt the second operating mode and isolates one or more power links of the second category from the electrical fault includes a power link of the first category that switched from its first operating mode to its second operating mode according to the second fault isolation stage.

[0058] The power distribution network may advantageously include at least one controller configured to control partial restoration of load sharing across power sources according to a third fault isolation stage by being configured to determine, based on at least one of a measured electrical quantity, a plurality of measured electrical quantities and data representing a current operating mode of one or more power links, which of a plurality of power links of a second type that switched from its first operating mode to its second operating mode according to the first fault isolation stage is isolated from the electrical fault by at least one other power link adopting the second operating mode and is therefore to switch back to the first operating mode to partially restore load sharing.

[0059] In this regard, local control of partial restoration of load sharing can be provided. For example, if the power link of the second type is formed by load channels of one or more solid-state power controllers of the power distribution network, the microcontroller of each corresponding solid-state power controller can be advantageously configured to control partial restoration of load sharing across the power source according to the third fault isolation stage, by being configured to monitor at least one current electrical condition of the corresponding load channel in the non-conductive state of its solid-state switch, preferably monitoring at least one corresponding current electrical condition on both load channel sides of the solid-state switch, for determining whether the load channel is isolated from the electrical fault by at least one other power link adopting the second operating mode and should therefore be switched back to the conductive state to partially restore load sharing.

[0060] According to another advantageous method, at least one superior controller of the power distribution network, for example a so-called solid-state power manager (SSPM) of a secondary power distribution unit (SPDU) in the case of implementing a corresponding SSPC distribution architecture, or an electrical system controller (ESC) of a vehicle management computer (VMC), or a flight control computer system of an aircraft, can be configured to control the partial restoration of load sharing across power sources according to a third fault isolation stage, by being configured to receive status data or status signals from one or more circuit protection devices or / and one or more solid-state power controllers, or / and by being configured to monitor the current electrical conditions of power channels or power channel portions of the power distribution network, and by being configured to determine, based on one or both of these status data and such monitoring, which of a plurality of power links of the second type currently in the second operating mode should be commanded to switch back to the first operating mode to partially restore load sharing.

[0061] To achieve at least one of the above objectives, the present invention further provides a method for operating an electrical system of an aircraft, the electrical 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 disposed within a respective power channel of the power distribution network and configured to enable power transmission via the respective power channel in a first operating mode of the power link and to prevent power transmission via the respective power channel in a second operating mode of the power link.

[0062] The method includes operating an electric power distribution network in at least one normal operating mode, which provides load sharing across power sources such that at least one group of the plurality of power sources collectively drives at least one associated group of the plurality of electrical loads via corresponding power channels, the corresponding power channels including at least one power channel having a power link that adopts a first operating mode.

[0063] The method also includes 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 including the electrical fault is isolated from at least one other network portion of the power distribution network by at least one power link adopting a second operating mode.

[0064] The method of the present invention provides a combination of the advantages of conventional separation methods and conventional unification methods without compromising security against critical faults, as discussed above with respect to the power system of the present invention.

[0065] 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 involving 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 these power channels of the first class, so that 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.

[0066] With respect to such an electric power distribution network, the method may advantageously involve changing the operating mode of one or more of the power links of the second category from a first operating mode to a second operating mode for isolating the electrical fault in the electrical fault mitigation mode.

[0067] The method may advantageously further involve maintaining one or more of the power links of the second class in the first operating mode, or / and may advantageously further involve changing the operating mode of one or more of the power links of the second class from the second operating mode to the first operating mode, for load sharing across the power sources in normal operating mode, or / and for restoring partial load sharing across the power sources in electrical fault mitigation mode.

[0068] Advantageously, the method of the present invention may generally comprise: i) a first fault isolation step of providing separation of power channels from each other by switching at least one power link from its first operating mode to its second operating mode; ii) a subsequent second fault isolation step of providing fault isolation within a power channel still affected by the electrical fault by switching a power link from its first operating mode to its second operating mode; and iii) a subsequent third fault isolation step of providing partial restoration of load sharing across power sources not affected by the electrical fault with respect to electrical loads not affected by the electrical fault by switching at least one power link from its second operating mode to its first operating mode, the at least one power link being isolated from the electrical fault by at least one other power link adopting the second operating mode.

[0069] If power channels of the first and second classes and power links of the first and second classes are provided, the method may advantageously include: i) a first fault isolation step, which provides separation of the power channels of the first class from each other by switching at least one power link of the second class from its first operating mode to its second operating mode; ii) a subsequent second fault isolation step, which provides fault isolation within the power channel of the first class still affected by the electrical fault by switching the power link of the first class included in this power channel from its first operating mode to its second operating mode; and iii) a subsequent third fault isolation step, which provides partial restoration of load sharing across power sources not affected by the electrical fault with respect to electrical loads not affected by the electrical fault by switching at least one power link of the second class from its second operating mode to its first operating mode, the at least one power link of the second class being isolated from the electrical fault by at least one other power link of the second class and adopting the second operating mode.

[0070] As discussed, significant advantages are achieved with respect to the power system of the present invention, which is configured to provide electrical fault isolation by subsequently undertaking first, second, and third fault isolation stages.

[0071] In view of the foregoing, the present invention provides a method for safely isolating electrical faults, particularly short circuits, in an electric power distribution network using two or more stages of circuit protection devices that function at different speeds. Advantageously, the unique fast isolation time and pre-settable characteristics of a solid-state power controller (SSPC) can be utilized to achieve safe load sharing while preventing the propagation of the electrical fault.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] A common type of aircraft equipment may be an electric lift / thrust unit for the aircraft.

[0076] 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.

[0077] 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, load sharing across multiple or all subgroups may be achieved via power links of the second type. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] 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.

[0079] Figure 2The 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.

[0080] 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.

[0081] Figure 4 In sub-figures a) and b) two types of lift / thrust units are schematically shown, which have three propulsion engines mounted to or integrated with the flaps, e.g. Figure 4 As shown in sub-diagram a) of , or having a propulsion engine mounted to or integrated with the flap, such as Figure 4 As shown in sub-figure b).

[0082] 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.

[0083] Figure 6 A general electrical power system for an aircraft is shown schematically.

[0084] Figure 7 An electrical power system of an aircraft is schematically shown with an electrical power distribution network illustrating a first conventional approach.

[0085] 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.

[0086] Figure 9 The electrical system of an aircraft is schematically shown, illustrating Figure 8 A variation of the conventional method.

[0087] Figure 10 A suitable linear 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.

[0088] Figure 11 Schematically illustrates the Figure 10 A first variant of the network topology.

[0089] Figure 12 Schematically illustrates the Figure 10A second variation of the network topology.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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

[0094] The following describes a "first method" and a "second method" for achieving the key advantages of conventional power network separation and conventional power network unification in an advantageous and synergistic manner. Both methods are methods of the present invention, and the examples provided for implementing both methods are non-limiting illustrative embodiments of the present invention. However, in the context of the present disclosure, the "first method" is preferred over the "second method."

[0095] 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.

[0096] 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.

[0097] 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).

[0098] 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.

[0099] 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.

[0100] Figure 2 The 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] Figure 4 Sub-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.

[0106] 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.

[0107] 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 .

[0108] Figure 4The corresponding flaps 234 with the propulsion modules 230 or propulsion engines 232 are schematically shown in a view from the rear of the aircraft.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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 .

[0114] 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.

[0115] 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 can be connected 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.

[0116] According to conventional methods, the power distribution network 306 will be implemented as a separate network with independent power channels, such as Figure 7As 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.

[0117] 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 electrical fault. Other power channels are not affected.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] based on Figures 10 to 15The 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.

[0126] 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.

[0127] 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.

[0128] 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 12The 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.

[0129] Even more advantageously, the connection channels of the second type are connected with their SSPCs in a ring configuration so that load sharing or partial load sharing is achieved across the power sources A, B, C and D with respect to the electrical loads AA, BB, CC and DD in the ring topology, e.g. 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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 corresponding 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.

[0135] 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.

[0136] First method

[0137] 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.

[0138] 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.

[0139] 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 sources 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.

[0140] 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.

[0141] 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 11 Other 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.

[0142] 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.

[0143] 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 .

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] For example, it may happen that in Figure 10 and Figure 11In 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] Since both possibilities have their advantages, it is possible to use Figure 12 Hybrid configuration shown.

[0155] 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.

[0156] 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.

[0157] The previous explanation of the three fault isolation phases applies similarly to Figures 10 to 15 Other 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.

[0158] 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.

[0159] Figure 16 exist Figure 16 Sub-figure a shows 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.

[0160] Figure 16Subfigure b of FIGURE 2 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. EPUs 1, 3, and 4 are located on the right front and rear wings, while 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, and EPUs 5 and 6 are located adjacent to each other on the left rear wing.

[0161] Figure 16 Subgraph c of 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 308a and 308b 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.

[0162] based on Figure 16 and Figure 16 The concept shown in sub-graph 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.

[0163] 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.

[0164] 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.

[0165] 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.

[0166] 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 16 The 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.

[0167] Second method

[0168] 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.

[0169] 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.

[0170] 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.

[0171] 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.

[0172] 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.

[0173] Suitable partial load sharing modes for phase 1 and phase 2 are as follows, for example:

[0174] 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

[0175] 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.

[0176] All power supplies have the opportunity to load share with other power supplies, either directly or via another source (if provided).

[0177] This solution is scalable to any number of power channels.

[0178] It is also possible to distribute power and loads to different phases, for example as shown below:

[0179] 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

[0180] 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.

[0181] However, no particular advantage is obtained compared to the first example.

[0182] 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:

[0183] 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

[0184] 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.

[0185] 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.

[0186] 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:

[0187] 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

[0188] 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.

[0189] 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:

[0190] stage Closed switch Open switch Power supply for load sharing 1 ab、ad bc、cd A vs. B vs. D

[0191] 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:

[0192]

[0193]

[0194] 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.

[0195] 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:

[0196] 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

[0197] 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.

[0198] 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.

[0199] 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.

[0200] 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.

[0201] 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.

[0202] 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.

[0203] 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.

[0204] An electrical power distribution network (306) of an electrical power system (300) of an aircraft is operated in at least one normal operating mode such that it provides load sharing across power sources (A, B, C, D) with respect to electrical loads (AA, BB, CC, DD), wherein in the event of an electrical power fault the electrical power distribution network (306) is operated in at least one electrical power fault mitigation operating mode such that electrical power fault isolation is provided such that a network portion of the electrical power distribution network (306) comprising the electrical power fault is isolated from at least one other network portion of the electrical power distribution network.

[0205] Reference numerals

[0206] 10 Flight Control System

[0207] 12 Flight Control Computer System

[0208] 12a, 12b, 12c flight control computers

[0209] 14, 16, 18, 20 Aircraft equipment

[0210] 22 Control bus system

[0211] 30a, 30b Left and right side rod devices

[0212] 32a, 32b Left and right side bars

[0213] 38a, 38b sensor assembly

[0214] 42a, 42b connection link

[0215] 200 canard-wing aircraft

[0216] 202 Left rear wing

[0217] 203 fuselage

[0218] 204 Right rear wing

[0219] 206 Left front wing

[0220] 208 right front wing

[0221] 210, 212, 214, 216; 234 flaps

[0222] 230 Propulsion Module

[0223] 232, 232a, 232b, 232c propulsion engines

[0224] 3.1 to 3.12 Lift / thrust unit on the left rear wing

[0225] 4.1 to 4.12 Lift / thrust unit on right rear wing

[0226] 1.1 to 1.6 Lift / thrust unit on the left front wing

[0227] 2.1 to 2.6 Lift / thrust unit on the right front wing

[0228] 236 Wing

[0229] 240 flap actuator

[0230] 242 pivot joint

[0231] 300 Power System

[0232] 302; A, B, C, D power supply

[0233] 304; AA, BB, CC, DD1, DD2, DD electrical load

[0234] 306 Electricity Distribution Network

[0235] 308; 308a; 308b; 308c; 308d Power channel; First type of power channel

[0236] 310; a, b, c, d Type I power train

[0237] 312, 314 power channels

[0238] 316; SW power link; switch

[0239] 314; 314a, 314b, 314c, 314d, 314e, 314f, the second type of power channel

[0240] 314g, 314h, 314i, 314j

[0241] 316; ab, bc, cd, ad, ac, ad, ax, bx, cx, the second type of power link

[0242] dx

[0243] 312, 314, 314a, 320 connecting channels

[0244] 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, a plurality of power sources, 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 of the power distribution network; wherein the power distribution network (306) comprises 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 from being transmitted between the driving power channel or the driving power channel portion and the driven power channel or the driven power channel portion; 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 (306) provides load sharing across the power sources (A, B, C, D) in the normal operating mode, such that at least one group of the plurality of power sources (A, B, C, D) jointly drives at least one group of associated electrical loads (AA, BB, CC, DD) among the plurality of electrical loads via their associated power channels or power channel portions and at least one power link associated therewith and in the first operating mode; wherein the power distribution network (306) provides electrical fault isolation in the electrical fault mitigation operating mode 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 the second operating mode; wherein the power distribution network (306) includes a plurality of power channels of a first type; wherein each power channel of the first category has associated therewith at least one associated power source (A; B; C; D), at least one associated power source (A; B; C; D) not being associated with another power channel of the first category, and wherein each power channel of the first category has associated therewith at least one of the electrical loads (AA; BB; CC; DD), at least one of the electrical loads (AA; BB; CC; DD) not being associated with another power channel of the first category, such that the 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, for enabling the at least one power source to drive the at least one electrical load via the corresponding power channel of the first category without involving driving via another power channel of the first category; wherein a plurality of power channels of the first kind 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 of a second kind for achieving load sharing, with respect to electrical loads (AA, BB, CC, DD) associated with the power channels of the first kind, across power sources (A, B, C, D) associated with at least one group of the power channels of the first kind or associated with all power channels of the first kind by transmitting power between the power channels of the first kind via at least one power channel of the second kind; wherein each of the power channels of the first type comprises a power link (310) of a first type from a plurality of the power links, the power link (310) of the first type allowing, in its first operating mode, the transmission of power from at least one associated power source (A; B; C; D) to at least one associated electrical load (AA; BB; CC; DD) via the power link of the first type, and prohibiting, in its second operating mode, the transmission of power from at least one associated power source to at least one associated electrical load via the power link of the first type; wherein each of the power channels of the second type includes a power link (316) of the second type from the plurality of power links, the power link (316) of the second type allowing power transmission between the power channels of the first type via the power link of the second type in the first operating mode thereof, and the power link (316) of the second type prohibiting power transmission between the power channels of the first type via the power link of the second type in the second operating mode thereof; and wherein each power link of said second category is configured to change its operating mode from said first operating mode to said second operating mode within a tripping time interval of a given order of magnitude in response to at least one preset or presettable electrical trip condition indicative of an electrical fault; Characterized in that each of the second type of power links (316) is provided by an associated solid-state power controller of the power distribution network, the solid-state power controller including a microcontroller, at least one load path forming the second type of power link, and at least one solid-state switch included in the load path and operable under the control of the microcontroller, wherein the microcontroller is configured to switch the solid-state switch between a conducting state corresponding to the first operating mode of the second type of power link and a non-conducting state corresponding to the second operating mode of the second type of power link, and is configured to monitor at least one current electrical condition of the load path for responding to the occurrence of an electrical trip condition by switching the solid-state switch from the conducting state to the non-conducting state.

2. The power system of claim 1 , wherein the power distribution network ( 306 ) is configured to provide load sharing across all power sources (A, B, C, D) in the normal operating mode, such that all power sources of the plurality of power sources jointly drive all electrical loads (AA, BB, CC, DD) of the plurality of electrical loads via corresponding power channels or power channel portions and corresponding power links in the first operating mode; and The power distribution network (306) is configured to adopt the electrical fault mitigation operation mode in a manner that enables an electrical fault occurring at a power source or an electrical load to be isolated, so that multiple or all power sources not affected by the electrical fault can drive multiple or all electrical loads not affected by the electrical fault.

3. The power system of claim 1 , 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 within a tripping time interval of a first order of magnitude in response to at least one preset or presettable electrical trip condition indicative of an electrical fault.

4. The power system according to claim 3, wherein the tripping time interval of the first order of magnitude of the power link (310) of the first category significantly exceeds the tripping time interval of the given order of magnitude of the power link (316) of the second category, and the tripping time interval of the given order of magnitude is the tripping time interval of the second order of magnitude.

5. The power system according to any one of claims 1 to 4, wherein the power distribution network (306) is configured to provide electrical fault isolation by subsequently undertaking at least three fault isolation stages when switching from the normal operating mode to the electrical fault mitigation operating mode in response to the occurrence of an electrical fault; wherein the first fault isolation stage provides isolation of power paths from one another by at least one power link switching from its first operating mode to its second operating mode; wherein a subsequent second fault isolation stage provides fault isolation within the power channel still affected by said electrical fault by the power link switching from its first operating mode to its second operating mode; as well as wherein a subsequent third fault isolation stage is provided by at least one power link switching from its second operating mode to its first operating mode to provide partial restoration of load sharing across power sources not affected by the electrical fault with respect to electrical loads not affected by the electrical fault, and by at least one other power link adopting the second operating mode to be isolated from the electrical fault.

6. An aircraft (200), comprising a power system (300) according to any one of claims 1 to 5; 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.

7. An aircraft according to claim 6, wherein the power system (300) includes at least one group of common types of electrical loads in the form of aircraft equipment, which 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 a plurality of said aircraft equipment can fail without endangering the flight capability and controllability of the aircraft, each subgroup of a plurality of said aircraft equipment including at least two common types of said aircraft equipment.

8. An aircraft according to claim 7, wherein the aircraft equipment or each corresponding subgroup of aircraft equipment is associated with a specific common power channel of the power distribution network (306) of the power system (300) for being driven together via this common power channel, and wherein the aircraft equipment or each corresponding subgroup of aircraft equipment is arranged in a symmetrically distributed manner and arranged at 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 common power channel and causes a fault of the aircraft equipment of this subgroup will not endanger the flight capability and controllability of the aircraft.

Images