Apparatus

Abstract

An electrical power distribution network 300 for an electrically powered aircraft (100, fig. 1) comprising an electrical power source 320, an essential power user 361 for example a propulsor, a non-es

Description

Technical Field The present invention is concerned with electrical propulsion systems and the arrangement of electrical power distribution networks within aircrafts. Electrical distribution systems connect power sources to electrical loads. There are several alternative power sources options (that are much more environmentally friendly than via typical combustion of fossil fuels) but many utilize air breathing engines such as gas turbines and fuel cells. One of the advantages of an electrical distribution that separates the power sources from the loads is that the distribution network provides architectural freedom to locate the electrical propulsion system and separate power generation system in preferred positions within the aircraft. For the separate power generation system, this often allows greater propulsion efficiency. This also allows preferred location of power source to the fuel system and air breathing sub-systems reducing fuel and air transportation and improving safety. Moreover, the location of power sources can also enhance aircraft design such as reducing weight suspended along the wing and providing centre of gravity benefits. When considering increased aircraft electrical loads and electric propulsion a number of challenges arise however. At least the following challenges exist: 1) The separate electrical propulsion distribution system and aircraft electrical distribution system compete for the same physical space in certain parts of the aircraft. This negates many of the architectural freedom benefits. 2) Both distribution systems require separate power sources. Though the scale (electric power levels) may electrically seem suitable when combined with the complexity of providing fuel and air source, the additional installed capacity incurs additional weight and drag. 3) Combining both distribution systems is complex because of the different scale of electrical distribution and the special states where one system is required and not the other such as aircraft start and maintenance. The arrangement disclosed herein provides great efficiency in an electrical propulsion, accounting for the drawbacks associated therewith, allowing environmentally friendly fuels to be used on large scale aircraft. Electrical propulsion systems have many benefits over combustion propulsion systems, particularly in relation to chemical emissions and the like. It is widely seen that electrical propulsion systems may render transport as more viable in a long term perspective. 5 There are however a number of problems inherent in the use of electrical propulsion over traditional combustion propulsion systems. In an attempt to increase the viability of electrical propulsion, attempts have been made to overcome such problems. We provide herein a further advancement in this area. 10 Summary of the Invention Aspects of the invention are set out in the accompanying claims. In accordance with some embodiments described herein, there is provided an electrical power distribution network for an electrically powered aircraft comprising: at least one electrical power source; at least one essential power user; at least one non-essential power user; a busbar arrangement comprising a plurality of busbars, wherein each busbar is connected to at least one of the at least one electrical power source, at least one of the at least one essential power user and at least one of the at least one non-essential power user; a controller arrangement arranged to: control electrical power delivery via the busbar arrangement from the at least one electrical power source, detect an operating failure state; detect essential power usage; and, detect non-essential power usage wherein the busbar arrangement is arranged to provide a different connection route for each busbar to at least one essential power user and at least one non-essential power user. The present distribution network provides excellent redundancy in response to a lack of operation of certain elements within the network. For example, this may occur during a safety event or the like. Moreover, the present system provides this excellent redundancy without requiring significant oversizing as per modern solutions. The busbar arrangement allows for elements of the network to be remotely distributed throughout the aircraft. In this way, locations for elements may be selected based on size and weight considerations. The flexibility of arrangement of the network leads to gains in the handling of overall weight and centre of mass of the aircraft. In use, when a fault occurs (e.g. an operating failure state) that limits the power of the network, the controller arrangement may detect essential power usage and non-essential power usage and subsequently arrange power through the network accordingly. Essential power usage may be power for propulsion or the like. It is reasonable to consider thrust as an essential power usage in an aircraft. In contrast, non-essential power usage may include entertainment systems within an aircraft or the like. The present network allows for isolation of a failure or a failed element as and when the failure occurs. The present network is therefore robust and highly reactive to failures within the network. The present network can continue to provide supply to essential power users based on an understanding of the power usage of those users and the power that can be provided by the network (appreciating any loss of power from failed elements within the network). In examples, the network further comprises a management system, arranged to, in response to detecting an operating failure state, receive signals from the controller arrangement and: assess an extent of failure; assess an extent of essential power usage; assess an extent of non-essential power usage; update power provision from at least one electrical power source to at least one essential power user and at least one non-essential power user. The management system provides a super structure that may sit above other elements and control the elements to provide overarching control of power distribution within the network. The management system ascertains the extent of failure, the extent of essential power usage and the extent of non-essential power usage and then controls distribution of power on a prioritised basis. For example, where the power requirements for the essential systems can be fully satisfied, the management system then provides power to the non-essential power systems according to requirements or desires. For example, the power may be provided to lighting in the aircraft prior to power being provided to the entertainment systems in the aircraft. It is reasonable to consider that certain non-essential power usage is of a higher (non-essential) priority than other non-essential power usage. The management system may deem that by reconfiguring the network, sufficient power can be provided to all power users, i.e. both essential and non-essential. The management system in such an instance is able to rearrange power distribution to avoid an impact on the operation of the full network and the aircraft as a whole. The management system provides therefore an integrated control solution for the network. In examples, at least one essential power user is a propulsion element. In examples, at least one essential power user is a propulsor. Such essential power users are reasonable considering the impact to the aircraft of not providing power for propulsion. The management system may prioritise provision of power to such elements when considering how to distribute power throughout the network to the various users of power. In examples, the least one essential power user comprises at least two propulsors, and wherein the busbar arrangement is arranged to provide each propulsor with two distinct busbar-to-propulsor connections. Such an arrangement provides increased redundancy for high priority power users. In this way, where one busbar connection to a propulsor is damaged or fails during use, power can still be provided to that propulsor via a different busbar connection. This provides a highly robust and safe power distribution network. In examples, the at least one electrical power source comprises at least one uni-directional electrical power source. In examples, at least one electrical power source comprises at least one fuel cell. In specific examples discussed herein, the power sources may be fuel cells or the like. Fuel cells may be seen as uni-directional power sources. Fuel cells are highly advantageous for use in power generation for aircraft. Fuel cells also offer sustainable power generation and are therefore beneficial from an environmental viewpoint. In examples, the network further comprises a plurality of energy storage systems, ESSs, arranged to be in connection with the busbar arrangement, wherein the busbar arrangement is arranged to provide each ESS in the plurality of ESSs with two distinct busbar-to-ESS connections. Such an arrangement provides increased redundancy for power provision. Alongside, e.g., a fuel cell arrangement (e.g. fuel cell or fuel cell stack), the network may additionally comprise a further power provider. Such a power source may be a storage system for example an electrical store. This may be delivered where required. In examples, the ESS comprises at least one of: at least one battery; and, at least one capacitor and / or super-capacitor. Such examples of ESSs are highly advantageous in aircraft for provision of additional power where required. Such moments may be during failure states. In examples, each of the plurality of busbars are electrically, thermally and magnetically isolated from one another, and wherein each electrically segmented channel is independently controllable by the controller arrangement. Advantageously, the busbars do not interact with each other in parasitic electrical behaviours. Such behaviours would include eddy currents and the like. In examples, the at least one non-essential power user comprises at least one of: surface controls and / or avionics; environmental control systems; navigation systems; communication systems; weather radar systems; thermal management systems; and, air delivery systems. Such examples are non-essential power users where the view is taken that propulsion is truly essential for safe landing of an aircraft. Systems within this list may be highly prioritised “non-essential” such that power can be provided to systems once the propulsion requirement is satisfied. For example, surface controls and / or avionics, navigation systems and communication systems may be highly prioritised non-essential power users while e.g. thermal management systems may be a lower priority. In examples, galley loads, loos and entertainment systems are low priority within the non-essential power users. Communication systems often have a variable priority. The communication system in an aircraft may use three forms of communication (SATCOM, HF and VHF). Only one of these is relevant at any one phase of flight. As such, the two forms of communication that are not used in that phase of flight will be low priority during said phase of flight. The relevant form of communication may be a priority non-essential power user. As noted above, priority may vary for the specific communication system. Users may define the priority of the non-essential power users as per their requirements. The controller arrangement allows for this and allows for handling of power delivery to non-essential power users. The network disclosed herein is able to provide power on a highly reactive and use-based process. The network achieves this at least in part by the smart controlling system within the network alongside the multi connection system. In particular, the smart controlling distinguishes between power users that form part of the propulsive power chain (propulsors, but e.g. also feeders, inverters) and power users that form part of the auxiliary / secondary power chain. The former are considered essential power users while the others are non-essential power users. In accordance with some embodiments described herein, there is provided an at least partially electrically powered aircraft comprising an electrical power distribution network according to any of the above embodiments or examples. In accordance with some embodiments described herein, there is provided a method of controlling an electrical power distribution network in an aircraft, the method comprising: i) receive signals indicative of power flow, at a controller, from at least one of: an electrical power source; a essential power user; a non-essential power user; a busbar arrangement comprising a plurality of busbars, wherein each busbar is connected to at least one of the at least one electrical power source, at least one of the at least one essential power user and at least one of the at least one non-essential power user; ii) receive, at the controller, a user input, wherein the user input indicates a thrust demand; iii) calculate, by the controller, an extent of essential power usage to provide the thrust of step (ii) and an extent of non-essential power usage; and, iv) send signals, by the controller, to at least one of the electrical power source, the essential power user, the non-essential power user, and the busbars wherein the signals indicate the calculated power required of step iii). In examples, the method further comprises the steps: (v) determine, by the controller, if at least one of the electrical power source, the essential power user, the non-essential power user, and the busbars has partially or wholly failed and, if not, return to step i), (vi) determine, by the controller, a failure of at least one of the electrical power source, the essential power user, the non-essential power user, and the busbars; (vii) isolate, by the controller, the failed electrical power source, essential power user, non-essential power user, and / or busbar from receiving signals; (viii) recalculate, by the controller, an extent of power usage required in each at least one of the electrical power source, the essential power user, the non-essential power user, and the busbars as per step iii); and, (ix) transmit, by the controller, signals relating to the recalculated extent of power usages of step (viii). Brief Description of the Drawings One or more embodiments of the invention will now be described, by way of example only, and with reference to the following figures in which: Figure 1 shows a schematic view of a modern aircraft; Figure 2 shows a schematic view of a modern distribution network; Figure 3 shows a schematic view of distribution network according to an example of the present disclosure; Figure 4 shows a schematic view of a portion of distribution network according to an example of the present disclosure; Figure 5 shows a schematic view of distribution network according to an example of the present disclosure; and, Figure 6 shows a schematic view of an electrically powered aircraft according to an example of the present disclosure. Any reference to prior art documents in this specification is not to be considered an admission that such prior art is widely known or forms part of the common general knowledge in the field. As used in this specification, the words “comprises”, “comprising”, and similar words, are not to be interpreted in an exclusive or exhaustive sense. In other words, they are intended to mean “including, but not limited to”. The invention is further described with reference to the following examples. It will be appreciated that the invention as claimed is not intended to be limited in any way by these examples. It will also be recognised that the invention covers not only individual embodiments but also combination of the embodiments described herein. The various embodiments described herein are presented only to assist in understanding and teaching the claimed features. These embodiments are provided as a representative sample of embodiments only, and are not exhaustive and / or exclusive. It is to be understood that advantages, embodiments, examples, functions, features, structures, and / or other aspects described herein are not to be considered limitations on the scope of the invention as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the spirit and scope of the claimed invention. Various embodiments of the invention may suitably comprise, consist of, or consist essentially of, appropriate combinations of the disclosed elements, components, features, parts, steps, means, etc, other than those specifically described herein. In addition, this disclosure may include other inventions not presently claimed, but which may be claimed in future. Detailed Description An invention described herein relates to electrical power distribution network within an electrical powered aircraft. A particular system for this invention may be an aircraft with an electrically drivable motor or a drivable motor that is at least partially electrically driven. For example, a propulsion source in the arrangements discussed may be fully or partially electrically powered. Partially powered aircraft may use thrust provided in part by electrical means and in part by combustion means. Figure 1 shows a simple schematic view of an electrical aircraft 100. These conventional aircraft with more-electric loads include an electrical distribution system that typically includes three segregated lanes of power from at least three independent power sources. Figure 1 represents the B787 that has 6 generators (channels), from 3 different generation power sources (two engines and APU) split into three lanes (each with two channels). As more-electric loads are located all around the aircraft, this aircraft distribution system must cover the whole aircraft as many of these loads are essential to the operation of the aircraft. For example tail actuation is located aft of the aircraft, wing ailerons, slats and flaps are located on the wing; flight navigation is located forward of the aircraft and environmental control systems are located in the centre of the aircraft. This therefore provides a spaced out and heavy power network arrangement. Figure 2 shows a modern power distribution network with two separate power sources that power electric propulsors and supporting flight actuation (rotating wing for VTOL operation) in a fault-tolerant configuration. Figure 3 shows a schematic view of distribution network 300 according to an example of the present disclosure. The network 300 comprises at least one electrical power source 320a, 320b. The electrical power sources 320a, 320b shown in the example of Figure 3 may be a series of power sources. For example, power source 320a may be a fuel cell stack. The fuel cell stack 320a may comprise a series of individual fuel cells such as fuel cell 321a. The power source 320b may be a fuel cell stack. The fuel cell stack 320b may comprise a series of individual fuel cells such as fuel cell 321b. The network 300 comprises at least one essential power user 361, 362. The essential power users 361, 362 may be two propulsion units 361a, 361b, 362a, 362b. In examples, the essential power users are propulsors. The at least one essential power user may comprise a series of propulsors e.g. sub units may represent multiple (e.g. four) propulsors or multiple (e.g. four) propulsion sub units or the like. As shown in Figure 3, the network 300 provides energy paths from the at least one electrical source 320a, 320b to the at least one essential power user 361, 362. The propulsors may have two units each 361a, 261b, 362a, 362b. Each may operate to provide thrust to the aircraft. This provides a level of redundancy in the network 300 and increases the overall safety of the aircraft. The network 300 comprises a busbar arrangement comprising a plurality of busbars 310a, 310b, wherein each busbar 310a, 310b is connected to at least one of the at least one electrical power source 321a, 321b, at least one of the at least one essential power user 361 and at least one of the at least one non-essential power user 362. The busbar arrangement connects a series of power sources to a series of power users. There are multiple separate busbars 310a, 310b to provide redundancy. Redundancy is advantageous in light of safety however this is used in the present arrangement to provide both redundancy and robustness and allowing the arrangement to preferential reconfigure the power provision using a consideration of the power available and the power required at the time. The busbar arrangement is arranged to provide a different connection route for each busbar to at least one essential power user 361 and at least one non-essential power user 362. Additional elements are shown in the network for Figure 3. These will be discussed shortly. What is not shown is a controller arrangement arranged to control electrical power delivery via the busbar arrangement from the at least one electrical power source, detect an operating failure state; detect essential power usage; and, detect non-essential power usage. The controller arrangement operates to obtain relevant information for the power distribution from the power sources. The controller arrangement may comprise a series of detectors or sensors for obtain the working condition (operational state) of various elements in the network. For example, a voltmeter or the like may be able to ascertain whether a power source is providing power at the expected rate. This may be used by the arrangement to detect whether a power source is able to provide a sufficient power output to not require reconfiguration of the power distribution in the network. Additional elements include external power sources such as energy storage systems, ESSs. The ESSs may be represented by elements 331a, 331b, 332a, 332b. These elements may be used to provide additional power to the busbars when there is a requirement for additional power. In a safety event, power source 321a may be able to provide power as expected. The power source 321a may fail entirely and therefore provide no power. In this event, the controller arrangement may arrange for an ESS 331a to provide an additional power to the busbar for distributing to the power users 361, 362. In this way, while a power failure (or operating failure state) may occur, no users receive reduced power as the ESSs 331a, 331b, 332a, 332b allows a manner of failure mitigation. The ESSs may be capacitors, super capacitors or batteries or the like. The network 300 comprises at least one non-essential power user 350a, 350b. The network 300 may have secondary aircraft systems (SASs) that are provided with power from the busbars 310a, 310b. Such secondary aircraft systems are shown as elements 350a, 350b. The SASs 350a, 350b may include systems such as galley loads, loos and entertainment systems. The SASs 350a, 350b may include systems such as navigation and communication systems. The SASs 350a, 350b may include the nose landing gear and the aileron control systems. The SASs 350a, 350b include all power users except for the propulsion generating power users. In the terminology used here, these users are non-essential power users. Of course, some may have power to be provided throughout a flight, such as aileron control. In use, the controller arrangement is able to limit power provided to the SASs 350a, 350b according to priority and power load requirement. The controller arrangement is able to prioritise to some extent the propulsion generators 361. The non-essential power users 350a, 350b may be two entertainment power users. The non-essential power users may be one entertainment power user and one communication system power user. In examples, the non-essential power users may be communication systems or environmental controls. In examples, the non-essential power users are not propulsion systems and therefore are not propulsors. The at least one non-essential power user may comprise a series of units that are non-essential such as weather radar systems. The non-essential power users may be ranked in priority. This priority ranking may be used to ascertain how much power should be provided during any operating failure (or the like) to the non essential power users. As an example, in a power safety event wherein a power source fails to provide power, the entertainment systems of the aircraft may be deprioritised and have no power directed to them. In contrast, energy continues to the essential power users for thrust and to a subset of non-essential power users such as navigation and communication systems. As shown in Figure 3, the network 300 provides energy paths from the at least one electrical source to the at least one non-essential power user. The network 300 may utilise various power converters and interface converters to provide electrical power with highly useful electrical characteristics. For example, the network 300 include dc / dc converters 341, 342 to provide power limiting capability. This function is controlled by the controller arrangement. In examples, converters 341, 342 are rated at 50%, 50% or at 100%, 0% respectively or 0%, 100% respectively (and at any reasonable value between). In additional total power (100%) could be reduced to only (80%) by changing to 40%, 40% respective rating or 80%, 0% respective rating or 0%, 80% respective rating. As can be seen, the routing in the network 350 provides a very high level of redundancy and allows power from the sources to be provided to the essential and non-essential power users according to the circumstances at hand. In higher failure states (e.g. power source 320 is unable to provide power), the controller arrangement will be selective over which users receive power and how much of their ideal power delivery their will receive. In such instances the controller may use energy from secondary power sources (such as EESs or the like). In such instances secondary aircraft systems may not receive power (or may receive the least possible power for minimal functioning). Referring now to Figure 4, there is a portion of a network 400 according to the present disclosure shown. The network portion 400 includes power sources 421a, 421b, 421c, 421 d, associated with a first busbar 410a (in a busbar arrangement). The network portion 400 includes power sources 422a, 422b, 422c, 422d associated with a second busbar arrangement 410b. The busbars provide energy to power users (as per the busbars of Fig 3) however the power users are not shown. The controller arrangement 470 is shown. The controller arrangement controls a connection 472 to be switched between an open state (not connecting the busbars) and a closed state (connecting the busbars). Where the power sources are providing the expected power output, i.e. that there are no operating failures (decreases in any performance output from the power sources are seen as included in the term “operating failure”), the busbars are electrically isolated from one another and the connection is open. Where there is an operating failure of any sort such as one or more power sources not providing the expected amount of power, such as power source 421a having failed, the controller arrangement 470 may look to connect the busbars 410a, 410b electrically so that the power sources can share the burden of the malfunctioning power source. In this way, when one or power sources are malfunction the burden for handling the power deficit is shared across more than one busbar such that the power loss is felt less severely. In the example shown, if power source 421a fails, in a normal arrangement power sources 421b, 421c, 421d are overrated to handle the power loss. In the present arrangement, the controller arrangement 470 can close the connection 472 such that the burden is shared with a further four power sources. Element 471 may be a reconfiguration element 471 or the like for actuating the connection 472 in response to signals from the controller arrangement 470. Referring now to Figure 5, there is shown an overview of a network 500. The network 500 includes a series of connections shown as “X”s. Each of the connections can be open or closed as controlled by the controller arrangement. The power paths through the network 500 from power source to power user can therefore be controlled by the controller arrangement and redundancy can be managed. The network 500 includes a series of fuel cells (FC1 etc), busbars (PB1 etc), SASs, propulsion power converters (PPC1 etc), propulsion motors (PM1 etc). There are an array of connections between these that the controller arrangement can actuate as deemed advantageous. In modern arrangements, redundancy is maintained for safety. In the present arrangement, redundancy can be reduced to allow for the system to react to operational failures and to better handle the provision of power to power users. For example, power between busbars can be provided by closing connections. This reduces redundancy but improves the tolerance to power failure for the system as a whole. Referring now to Figure 6, there is shown a network according to the disclosure within an aircraft. The aircraft 600 may be an electrically powered aircraft. By this, the aircraft may be fully electrically powered or partially electrically powered. The aircraft has the network as described above. The aircraft 600 has a series of power sources that feed power users. The power sources also provide power to power distribution centres in the aircraft. The power sources may also provide power to secondary distribution centres. The network of Figure 6 has a series of primary power distribution centres PDCs. There is a first channel power distribution centre Ch1 PDC, a second channel power distribution centre Ch2 PDC, a third channel power distribution centre Ch3 PDC, and a fourth channel power distribution centre Ch4 PDC. The port-side has Ch1 PDC and Ch3 PDC (as per convention) while the starboard side has Ch2 PDC, Ch4 PDC. Such an arrangement of PDCs improves redundancy and safety. Where a port side failure occurs, the starboard systems should remain operational and therefore overall safety is significantly improved. The primary power distribution centres connect to a series of secondary distribution centres SDCs. In particular, Ch1 PDC connects to a SDC1-3 in the middle portion of the aircraft 600, a SDC 1-3 in the aft portion of the aircraft 600 and a SDC 1-3 in the fore portion of the aircraft 600. Each of these may be so located to be proximal to the power users associated with that portion of the aircraft 600. This leads to a lesser amount of wiring being required and providing a more lightweight system and therefore a system that requires less fuel to operate. In particular, Ch1 PDC feeds the propulsion units that are located in the middle portion of the aircraft 600. SDC 1-3 in the fore portion of the aircraft 600 may feed nose landing gear, communication systems and navigation systems in the cockpit alongside landing lights and de-icing systems. SDC 1-3 in the aft portion of the aircraft 600 may feed the rudder and elevators as well as the fuel cell balance of plant and the avionics bay. SDC 1-3 in the middle portion of the aircraft 600 may feed the main landing gear, the galley systems including environmental control systems and the entertainment systems. The same arrangement can be found on the starboard side with Ch2 PDC and Ch4 PDC feeding secondary distribution centres SDCs on that side, in particular SDC 2-4 located in fore, middle and aft locations. By feeding the SDCs by two PDCs, there is additional redundancy and therefore improved resilience against loss and faults. There may be connections located between the PDCs that may be actuatable by a controller arrangement as required. In examples, the Ch2 PDC may experience a fault with a power source. The controller arrangement may ascertain that the fault is significant enough that the remaining power sources for Ch2 PDC cannot account for the loss of power. The controller arrangement may connect Ch2 PDC to any of Ch1 PDC, Ch3 PDC and / or Ch4 PDC to share the lost power load and reduce the impact on the system of power users as a whole. Essential level power users may be connected to each of Ch1 PDC, Ch2 PDC, Ch3 PDC, Ch4 PDC to provide the highest likelihood that the systems remain operational in light of failure. Less important power users may only be connected to some or one of Ch1 PDC, Ch2 PDC, Ch3 PDC, Ch4 PDC. Where that PDC fails, it may be that less important power users cannot be provided with sufficient power and will fail. It can be seen that the propulsion motors PM1, PM2 are connected to each of Ch1 PDC, Ch2 PDC, Ch3 PDC, Ch4 PDC. In contrast, in the example of figure 6, no SDC connects to each of Ch1 PDC, Ch2 PDC, Ch3 PDC, Ch4 PDC. For additional redundancy the arrangement of power distribution cables may be such that cables are fed through upper and lower portions of the aircraft. For example, the cable for Ch1 PDC may be arranged on an upper port side of the aircraft, while the cable for Ch3 PDC may be arranged on a lower port side of the aircraft. The same may apply respectively for Ch2 PDC and Ch4 PDC. Again, this improves the resilience of the arrangement. In this way, unless there is a fault that impacts both sides as well as the upper and lower portions of the aircraft, some power system should function in the present arrangement. As such, the present arrangement provides excellent levels of resilience against all but the most significant faults. The arrangement of the present network allows for intelligent re-configuration units. Indeed, with many PDCs and many SDC connections, the re-configuration unit is able to account for many faults and provide a system that prioritises power users and therefore maximises safety of flight. The re-configuration unit alongside the controller arrangement maintains supply in light of power source failure. The arrangement of connections in the network allows for isolation of failures and power load sharing. This arrangement is robust and highly reliable. The controller arrangement and re-configuration unit are intelligent to establish when to switch to optimize between failure cases on the electric aircraft distribution system and / or electric propulsion system. The failures discussed herein may relate to power sources or additionally or alternatively may relate to any aspect of the network of the aircraft. The controller arrangement and reconfiguration element may additionally or alternatively be arranged to detect power usage based on historic power usage. This may be used to provide an expected power load from aspects of the network. In this way, the controller arrangement 335 may provide a proactive and robust solution to power management. Changes in power load that occur repeatedly (e.g. at take off and during climb) can be better accounted for in the moment by predictive power load handling (such as landing gear noted above). In this way, the need for the power from elements within the network can be detected on a current amount (i.e. immediate single measurement) on an ongoing basis (i.e. a tracked series of measurements) or on an expected amount (i.e. predictive based on historic use). As discussed above, when a failure is identified, the controller arrangement is able to detect an extent of the failure. This ascertains in broad terms what the percentage of power loss has occurred and can be expected to occur in future (e.g. if a failure state is likely to spread prior it being contained via connection actuation). When this is ascertained, the controller is able to control the linking of busbars, the isolation of elements and the reduction of power to non-essential power users. This is a form of management system that sits above the system is a super structure that provides the control over the operation of the whole network. This is a change from modern approaches. Electric power controllers on the electric propulsion bus and aircraft power distribution controller oversee operation of the electric aircraft distribution. These controllers are in communication with each other to ensure safe and optimum operation. Control algorithms may allow highly effective power flow performance. These are the highest control elements that control the network functions. As noted above, both the fuel cells and the ESSs may be used to provide power to power users. The fuel cells may be uni-directional while the ESSs may be bi-directional. It may desirable to locate the ESS in close location to the interface power converters to provide a level of power quality isolation between the aircraft electrical distribution and electrical propulsion bus. In a preferred embodiment, the system may have 4 separate power generation sources across four channels but physically configured into three lanes to meet conventional aircraft electrical distribution systems. The network may include additional elements for safety such as intelligent protection units to prevent electrical overloads or the like. The protection units may adapt “make” and “break” settings to match the aircraft state and aircraft safety case. For example if the protection is set for the higher electric propulsion power levels then it will not be able to detect any issues at the lower current levels required by the aircraft distribution system during the special cases such as start. In the above, a network is disclosed that is robust and reactive to power failures. In the above, essential and non-essential power users have been discussed. While this may vary based on the controller arrangement and user preference, in the above this has been considered in specific examples. In some examples, essential users are considered those that convert electrical energy into propulsion. This may be joined by other similar systems that enable flight. Non-essential power users may be those that use electrical energy to improve the comfort of passengers, for example air conditioning or entertainment systems. In a safety event, it is not needed to prioritise passenger comfort rather it is preferable to prioritise flight resiliency. The systems disclosed herein provides this performance and is an improvement over modern systems.

Claims

1. An electrical power distribution network for an electrically powered aircraft comprising:at least one electrical power source;at least one essential power user;at least one non-essential power user;a busbar arrangement comprising a plurality of busbars, wherein each busbar is connected to at least one of the at least one electrical power source, at least one of the at least one essential power user and at least one of the at least one non-essential power user;a controller arrangement arranged to:control electrical power delivery via the busbar arrangement from the at least one electrical power source;detect an operating failure state;detect essential power usage; and, detect non-essential power usagewherein the busbar arrangement is arranged to provide a different connection route for each busbar to at least one essential power user and at least one non-essential power user.

2. A distribution network according to claim 1, further comprising a management system, arranged to, in response to detecting an operating failure state, receive signals from the controller arrangement and:assess an extent of failure;assess an extent of essential power usage;assess an extent of non-essential power usage;update power provision from at least one electrical power source to at least one essential power user and at least one non-essential power user.

3. A distribution network according to claim 1 or 2, wherein at least one essential power user is a propulsion element.

4. A distribution network according to any of claims 1-3, wherein at least one essential power user is a propulsor.

5. A distribution network according to claim 4, wherein the least one essential power user comprises at least two propulsors, andwherein the busbar arrangement is arranged to provide each propulsor with two distinct busbar-to-propulsor connections.

6. A distribution network according to any of claims 1 -5, wherein the at least one electrical power source comprises at least one uni-directional electrical power source.

7. A distribution network according to any of claims 1 -6, wherein the at least one electrical power source comprises at least one fuel cell.

8. A distribution network according to any of claims 1-7, further comprising a plurality of energy storage systems, ESSs, arranged to be in connection with the busbar arrangement, wherein the busbar arrangement is arranged to provide each ESS in the plurality of ESSs with two distinct busbar-to-ESS connections.

9. A distribution network according to claim 8, wherein the ESS comprises at least one of: at least one battery; and, at least one capacitor and / or super-capacitor.

10. A distribution network according to any of claims 1-9, wherein each of the plurality of busbars are electrically, thermally and magnetically isolated from one another, and wherein each electrically segmented channel is independently controllable by the controller arrangement.

11. A distribution network according to any of claims 1-9, wherein the at least one non-essential power user comprises at least one of:surface controls and / or avionics;environmental control systems;navigation systems;communication systems;weather radar systems;thermal management systems; and, air delivery systems.

12. An at least partially electrically powered aircraft comprising an electrical power distribution network according to any of claims 1-11.

13. A method of controlling an electrical power distribution network in an aircraft, the method comprising:i) receive signals indicative of power flow, at a controller, from at least one of:an electrical power source;a essential power user;a non-essential power user;a busbar arrangement comprising a plurality of busbars, wherein each busbar is connected to at least one of the at least one electrical power source, at least one of the at least one essential power user and at least one of the at least one non-essential power user;ii) receive, at the controller, a user input, wherein the user input indicates a thrust demand;iii) calculate, by the controller, an extent of essential power usage to provide the thrust of step (ii) and an extent of non-essential power usage; and,iv) send signals, by the controller, to at least one of the electrical power source, the essential power user, the non-essential power user, and the busbars wherein the signals indicate the calculated power required of step iii).

14. A method according to claim 13, further comprising the steps:(v) determine, by the controller, if at least one of the electrical power source, the essential power user, the non-essential power user, and the busbars has partially or wholly failed and, if not, return to step i);(vi) determine, by the controller, a failure of at least one of the electrical power source, the essential power user, the non-essential power user, and the busbars;(vii) isolate, by the controller, the failed electrical power source, essential power user, non-essential power user, and / or busbar from receiving signals;(viii) recalculate, by the controller, an extent of power usage required in each at least one of the electrical power source, the essential power user, the non-essential power user, and the busbars as per step iii), and(ix) transmit, by the controller, signals relating to the recalculated extent of power usages of step (viii).

Images