Energy management system for a hybrid aircraft

Abstract

The invention relates to an energy management system for an aircraft having a hybrid energy source comprising at least three stored electrical energy sources and one electrical generation source, a detector (200) for determining state data, a state machine (210) for determining a control state of the energy sources, an adapter (220) for determining a backup electrical configuration when the state data indicate a fault, a power manager (230) for electrically controlling the one or more stored electrical energy sources and the one or more electrical generation sources, and a switch (240) for issuing commands to the switches of the power consumption electrical circuit of the aircraft. The power manager (230) is designed, in the presence of a backup electrical configuration indicating pooling of two or more stored electrical energy sources, to determine whether the voltage levels of the two or more stored electrical energy sources enable this pooling, and the switch (240) being designed to implement the pooling of two or more stored electrical energy sources if the determination carried out by the power manager (230) is positive.

Description

[0001] Energy management system for hybrid aircraft The invention relates to the field of aircraft and more particularly to the field of aircraft with hybrid electric engines. The electrification of aviation is one of the major challenges of the beginning of the 21 ecentury. This electrification is currently based on two types of solutions: fully electric solutions, and hybrid solutions. In the first type of solutions, the energy source is based exclusively on batteries, which must therefore be recharged between two flights. In the second type of solutions, developed by the Applicant, stored electrical energy sources (typically batteries) coexist with electrical generation sources (typically turbines or fuel cells, or other). In this second case, it becomes possible to imagine scenarios in which the electrical generation sources are used to recharge one or more stored electrical energy sources in flight. These scenarios nevertheless represent significant challenges. Indeed, in the field of aviation, it is crucial not to create a "Single point of failure" (or SPOF,single point of failure in French) for obvious safety reasons. It is therefore necessary both to have several sources of stored electrical energy to continue to ensure a supply of electrical energy if one of the sources of stored electrical energy fails but also to isolate them from each other to avoid any propagation of failure, and therefore the creation of SPOF. This isolation is not without consequences, and it carries with it a risk of creating significant voltage differences between the sources of stored electrical energy. Indeed, the electrical characteristics of the circuits of the latter can be slightly different, and therefore generate a different discharge for each source of stored electrical energy. This different discharge results in a different state of charge and therefore a different voltage for each source of stored electrical energy,since the voltage depends on the state of charge of the stored electrical energy source. The occurrence of a failure is therefore likely to render unusable stored electrical energy sources not affected by this failure, whereas these could be useful for providing greater autonomy to the aircraft. To date, the problem is such that, to the knowledge of the Applicant, there is no hybrid solution that makes it possible to manage a failure in flight other than by using power electronics whose weight is too penalizing, or by oversizing all the elements to cover cases where stored electrical energy sources become unusable due to a failure on an electrical branch to which they are attached. Only the Applicant has proposed a solution in the patent application published under number WO2022 / 238653. The invention improves the situation. To this end,it proposes an energy management system for an aircraft with a hybrid energy source comprising at least three stored electrical energy sources and an electrical generation source which comprises: - a detector arranged to determine on the one hand state data indicating a state of the elements of the electrical power consumption circuit of the aircraft controlled by the energy management system, and on the other hand energy data relating to the instantaneous electrical power requested by the aircraft and / or the current of the stored electrical energy sources of the aircraft, and / or the charging state of the stored electrical energy sources of the aircraft, - an automaton arranged to receive the energy data from the detector and to determine a control state of the energy sources,the automaton comprising at least three states in the group comprising: * a buffer state in which the instantaneous electrical power requested is less than the capacity of the electrical generation source(s) and is supplied by the latter, * a charging state in which the instantaneous electrical power requested is less than the capacity of the electrical generation source(s) and is supplied entirely by the electrical generation source(s), and in which the electrical generation source(s) produces surplus power used to recharge the stored electrical energy source(s), * a turbo state in which the instantaneous electrical power requested is greater than the capacity of the electrical generation source(s), and where the stored electrical energy source(s) provides the supplement necessary to achieve the instantaneous electrical power requested,- an adapter arranged to receive the status data and to determine a backup electrical configuration when the status data indicates a failure, - a power manager arranged to receive the status information from the controller and to determine an electrical command for the stored electrical energy source(s) and the electrical generation source(s), and - a switch arranged to issue commands to the switches of the aircraft power consumption electrical circuit controlled by the energy management system to implement a nominal electrical configuration, or, in the event of receipt of a backup electrical configuration from the adapter, this backup electrical configuration. The power manager is further arranged, in the presence of a backup electrical configuration indicating the pooling of two or more stored electrical energy sources,to determine whether the voltage levels of said two or more stored electrical energy sources allow this pooling, and the switch being arranged to implement said pooling of two or more stored electrical energy sources if the determination by the power manager is positive. Thanks to this energy management device, it is possible to pool all the stored electrical energy sources after a failure, which makes it possible to maximize the usable energy for the remainder of the flight. According to various embodiments, the invention may have one or more of the following characteristics: - when the determination by the power manager is negative, the system is arranged to implement one or more of the following strategies: * when said two or more stored energy sources cannot be pooled,the energy system implements sequential charging by prioritizing the stored energy sources among said two or more stored electrical energy sources having the lowest voltage levels, * when some of the stored electrical energy sources among said two or more stored electrical energy sources can be pooled, but less than indicated by the backup electrical configuration, the energy management system pools poolable stored electrical energy sources having the lowest charge level, * if two stored electrical energy sources among said two or more stored electrical energy sources can be pooled but not a third, these two stored electrical energy sources are pooled,and the energy management system recharges the third in a manner adapted to allow the fastest possible pooling with the other two, * if more than two electrical energy sources among said two or more than two stored electrical energy sources are to be pooled, the energy management system carries out the pooling in several stages, first by pooling two stored electrical energy sources and then adding each time a stored electrical energy source; - the system further comprises an in-flight recharging control device arranged to communicate with the power manager and the switch to control the recharging of the stored electrical energy sources of the aircraft in a grouped manner, and the power manager is further arranged to detect a transition between a vertical flight phase and a horizontal flight phase,and to communicate with the in-flight charging control device and the switch in order to control the charging of the stored electrical energy sources of the aircraft in a grouped manner upon detection of a transition from a vertical flight phase to a horizontal flight phase, and to deactivate the charging of the stored electrical energy sources of the aircraft in a grouped manner upon detection of a transition from a horizontal flight phase to vertical flight: - the at least two stored electrical energy sources each associated with at least one electrical switch, and in which the in-flight charging control device comprises * a matcher arranged to receive a status indicator of each electrical generation source as well as a status indicator of each stored electrical energy source, to determine one or more charging groups each associating an electrical generation source with two stored electrical energy sources,and to transmit each load group to a respective supervisor, * each supervisor being arranged to implement a state machine selected from the group comprising a stop state, a wait state, a unit precharge state, a unit charge state, a grouped precharge state, a coupling state and a grouped charge state, to retrieve input data comprising a current state machine state, an aircraft grouped charge indicator, a state indicator and a current intensity indicator of the electrical generation source of its load group, a load indicator, a voltage indicator and a maximum available power indicator for each stored electrical energy source of its load group, to determine a new current state machine state from the input data, as well as a direct current setpoint for each stored electrical energy source of its load group,and to transmit the new current state of the state machine and the direct current setpoints to a load parameter calculator, * the load parameter calculator being arranged to determine, for each stored electrical energy source, a direct voltage setpoint, a direct current to direct voltage transition setpoint, a load stop indicator and a forced load indicator from the current state of the state machine and the direct current setpoints of each supervisor as well as an opening or closing setpoint for the electrical switches associated with the stored energy sources to allow electrical grouping thereof; - each supervisor is instantiated in software on the basis of the transmission by the pairer; - the supervisors are always available,and wherein the call by the pairer creates a link between each supervisor and a load group; - the pairer is arranged to determine one or more load groups comprising more than two sources of stored electrical energy; - the pairer is arranged to access load groups which are defined for an operating time of the device corresponding to a flight; and - the pairer is arranged to determine the load groups dynamically. Other characteristics and advantages of the invention will appear better on reading the following description, taken from examples given for illustrative and non-limiting purposes, taken from the drawings in which: - Figure 1 represents a schematic diagram of an aircraft comprising a device according to the invention, - Figure 2 represents a generic diagram of the energy management system of Figure 1, - Figure 3 represents a generic diagram of the in-flight charging control device of Figure 2,- Figure 4 represents an example of configuration in the event of a failure, - Figure 5 represents a state machine implemented by the device of Figure 3, - Figure 6 represents an electrical diagram explaining the pooling of two stored electrical energy sources, and - Figure 7 an example of distribution of the batteries, the turbogenerators and the motors on the aircraft. The drawings and the description below contain, for the most part, elements of a certain nature. They may therefore not only serve to better understand the present invention, but also contribute to its definition, if necessary. Figure 1 represents a schematic diagram of an aircraft 2 comprising a device 4 according to the invention. As can be seen in Figure 1, an aircraft 2 according to the invention comprises an energy management system 4 according to the invention, two horizontal drive groups 6 and 8, four vertical drive groups 10, 12, 14 and 16,and two electrical generation sources 18 and 20. This type of aircraft is extremely innovative and is particularly suitable for demonstrating the potential of the energy management system 4. However, the aircraft could have a simpler architecture, for example a single horizontal drive unit, one or two vertical drive units and a single electrical generation source. Still alternatively, the aircraft could not be of the VTOL type, but be of another type, for example a “classic” hybrid conventional take-off (also called CTOL for Conventional Take-Off and Landing in English) aircraft. In this case, the vertical drive units will generally be called take-off drive units, while the horizontal drive units will generally be called cruise drive units. Still alternatively,there will no longer be a distinction between two drive groups of distinct types. In the variant described above, the “conventional” hybrid aircraft has a vertical flight phase in which the vertical component of the speed of the hybrid aircraft is non-zero. For example, the vertical flight phase corresponds to a takeoff, a descent or a landing of the aircraft 2. Still in this variant, the horizontal flight phase corresponds to the part of the cruise in which the vertical component of the speed of the hybrid aircraft is substantially zero. In the example described here, the horizontal drive group 6 (respectively 8) comprises a direct current to alternating current converter 22 (respectively 32), an electric motor 24 (respectively 34) and a thruster 26 (respectively 36),for example with a propeller. The propeller 26 (respectively 36) is arranged to allow the aircraft to move forward in a substantially horizontal direction. In the example described here, the propeller 26 (respectively 36) consumes a power of 80 kW in flight mode. The horizontal drive group 6 (respectively 8) is connected at the input to a switch 28 (respectively 38) which makes it possible to connect this input to the output of the vertical drive group 10 (respectively 14) or 12 (respectively 16), as described below. The vertical drive group 10 (respectively 12, 14, 16) comprises a rotor 42 (respectively 46, 72, 76) driven by a motor 52 (respectively 56, 82, 86), a rotor 44 (respectively 48, 74, 78) driven by a motor 54 (respectively 58, 84, 88). The motors 52 and 54 are powered by a respective direct current to alternating current converter 62 and 64 (respectively 66 and 68, 92 and 94,96 and 98). The DC to AC converters can also be called “inverters” and are arranged to generate an alternating current from a direct current. The DC to AC converters 62 and 64 (respectively 66 and 68, 92 and 94, 96 and 98) are connected to an electrical bus of the vertical drive group 10 (respectively 12, 14, 16), to which a battery 50 (respectively 60, 80, 90) is connected, as well as an input connected to an electrical distribution bus 108 of the electrical generation source 18, an input connected to an electrical distribution bus 110 of the electrical generation source 20. The batteries each constitute a source of stored electrical energy,whose coupling with the electrical generation sources establishes the hybrid nature of the invention. Finally, the electrical bus of each of the vertical drive groups 10 and 12 (respectively 14 and 16) is connected to a respective output of the latter, which is connected to the switch 28 (respectively 38). As will be seen below, the batteries 50, 60, 80 and 90 together deliver 600kW when they deliver 100% of their capacity. In the example described here, each electrical generation source 18 (respectively 20) comprises on the one hand a turbine generator 100 (respectively 102) and an alternating current to direct current converter 104 (respectively 106). In the example described here, each turbine generator can deliver 40kW at 100% of its capacity. Alternatively, the electrical generation sources could be other sources of electricity production,with direct or alternating current followed by an alternating current to direct current converter or a direct current to direct current converter. Thus, these sources could be based on turbogenerators powered by conventional fuel, biofuel, or synthetic fuels. Still alternatively, a hydrogen-based energy source, such as a fuel cell could be used. As will be seen with Figure 2, the energy management system 4 is arranged to control on the one hand the electrical generation sources 18 and 20, on the other hand the switches 28 and 38, but also as well as various protection elements not shown in Figure 1. When analyzing Figure 1, it appears that all the motor and electrical elements are duplicated. Thus, one-fail-safe can be ensured. Indeed, there are two horizontal drive groups,four vertical drive groups themselves forming two subgroups connected to the same horizontal drive group, and two electrical generation sources. Beyond this fairly standard duplication, it is the electrical buses specific to each vertical drive group, as well as the electrical distribution bus 108 and 110 specific to each electrical generation source which make it possible to achieve the one-fail-safe objective in operation of "discharging" the stored electrical energy sources, that is to say, when the stored electrical energy sources are stopped or supplying electric current to the electric motors. In the case of recharging of these stored electrical energy sources by one or more electrical generation groups,An obvious method of recharging the electrical energy storage sources would be a complete parallel connection at the level of the electrical buses 108 and 110. This method would then have the disadvantage of creating a SPOF as described previously. Indeed, as will be seen below, the particular structure of the aircraft in Figure 1 allows for a real hybridization of the electrical energy sources, as opposed to existing solutions in which it is a juxtaposition. Thus, depending on the power requirements, both the batteries and the electrical generation sources can operate in concert. But beyond that, this architecture allows the batteries to be treated as pure "energy buffers". The batteries are treated in a completely passive manner,without any need for software or hardware intelligence other than the basic intelligence required to operate the battery system (better known by the English acronym BMS for "Battery Management System"). Such a system makes it possible to perform functions such as monitoring parameters – voltage, temperature, state of charge, state of health, etc. –, preventing any risk of going outside the intended operating range – overvoltage, overcurrent, overheating, etc. – or optimizing battery capacity. This goes completely against all existing solutions, in which either an element is specifically designed to optimize battery operation, and plays a control role, or an element is designed to compensate for any possible battery weakness, but in exclusive alternation,that is to say without the batteries and this element being capable of operating simultaneously. Figure 2 represents a schematic diagram of the energy management system 4 of Figure 1. As can be seen in this figure, the energy management system 4 comprises a detector 200, an automaton 210, an adapter 220, a power manager 230, a switch 240 and a recharge control device 250. The detector 200 is a system arranged to receive various data from the aircraft 2, which it will optionally process and transmit totally or in part on the one hand to the automaton 210, and on the other hand to the adapter 220. Thus, the data received by the detector 200 are of two main types: - on the one hand, state data indicating a state (level of stress, temperature, limit, operating state, failure state,etc.) of the elements of the electrical power consumption circuit of the aircraft controlled by the energy management system 4, and - on the other hand energy data relating to the instantaneous electrical power required by the motors 52, 54, 56, 58, 82, 84, 86, 88 of the rotors 42, 44, 46, 48, 72, 74, 76, 78 and / or the motors 24 and 34 of the thrusters 26 and 36, and / or the current of the stored electrical energy sources of the aircraft 50, 60, 80 and 90 and / or the charging state of the stored electrical energy sources of the aircraft 50, 60, 80 and 90. Thus, the detector 200 has an overall view of the functional state of the elements linked to the consumption of electrical power, that is to say on the one hand the presence of a breakdown or not as well as the flight phase of the aircraft 2, but also the energy state of these elements. In what follows, the expression instantaneous electrical power requested will always designate the electrical power which is called by the motors 52, 54, 56, 58,82, 84, 86, 88 of the rotors 42, 44, 46, 48, 72, 74, 76, 78 and / or the motors 24 and 34 of the thrusters 26 and 36, unless another definition is explicitly mentioned. The automaton 210 is in the example described here a finite automaton, an exemplary embodiment of which is shown in FIG. 3. As can be seen in this figure, the automaton 210 has four possible states: - a state 300 called "buffer", in which the instantaneous electrical power requested is less than the capacity of the electrical generation source(s) 18 and 20, and is supplied entirely by the latter, - a state 310 called "load", in which the instantaneous electrical power requested is less than the capacity of the electrical generation source(s) and is supplied entirely by the electrical generation source(s),and in which the electrical generation source(s) produces a surplus of power used to recharge the stored electrical energy source(s), - a state 320 called "turbo" in which the instantaneous electrical power requested is greater than the capacity of the electrical generation source(s), and where the stored electrical energy source(s) provides the necessary supplement to reach the instantaneous electrical power requested, and - an optional state 330 called "silent", in which the electrical energy sources 18 and 20 are voluntarily stopped in order to reduce noise pollution, which also makes it possible to reduce the emission of pollutants. The automaton 210 has transitions which are provided to ensure: - on the one hand a minimal risk in the determination of the state transitions, in order to limit the risks of failure linked to the automaton 210 (and therefore to the energy management system 4),- on the other hand, recharging the batteries 50, 60, 80, 90 as frequently as possible. For this reason, the state transitions are based on two variables: - the current produced by the electrical generation sources or the current of the stored electrical energy sources, - the recharging rate of the batteries 50, 60, 80, 90. As a priority, as soon as the instantaneous electrical power requested exceeds the electrical power capacity of the electrical generation sources 18 and 20, the buffer state or the charging state switches to the turbo state. Indeed, in this case, it is crucial to operate the batteries 50, 60, 80, 90 and the electrical generation sources 18 and 20 simultaneously in order to provide sufficient electrical power to implement the flight controls. Secondarily, when the instantaneous electrical power requested is less than the electrical power capacity of the electrical generation sources 18 and 20,the priority is to recharge the batteries. Thus, the automaton 210 can transition from the buffer state to the charging state or to the turbo state, and from the charging state to the turbo state, and it can transition from the charging state to the buffer state or from the turbo state to the buffer state. On the other hand, it cannot transition from the turbo state to the charging state: it must first transition to the buffer state. The reason for this is that, in this way, each state transition is conditioned by a single change of condition relating either to the instantaneous electrical power requested, or to the state of charge of the batteries. Thus, the reliability of the automaton 210 is improved because the risks of several successive transitions or non-transitions are minimal. In other embodiments, the transitions between the states could be carried out differently,for example to avoid power variations linked to the transition to the buffer state. The silent state 330 is for its part an option in the sense that it depends on manual activation by the pilot of the aircraft 2. Thus, the latter sends a command to switch off the electrical generation sources 18 and 20 which transitions any state to the silent state. In the same way as for the charge and turbo states, when this command is deactivated, the automaton 210 transitions again to the buffer state. The buffer state thus constitutes a start-up state and a fundamental state in that it makes the operation of the automaton 210 more reliable. It should be noted that the parameters defining the transitions can be varied. Thus, the transition from the buffer state to the charge state can be conditioned by a charging threshold of the batteries 50, 60, 80, 90, and this threshold can itself be modified according to the operational state,functional and / or the flight program of the aircraft 2. Similarly, the electrical power capacity of the electrical generation sources 18 and 20 may be modified according to the operational, functional state and / or the flight program of the aircraft 2. For example, in certain failure cases, it may be necessary to operate one or more of the electrical generation sources 18 and 20 at a capacity greater than their nominal capacity, for example 120%. It is then appropriate to adapt the transition threshold to the turbo state accordingly. This adaptation is carried out in the example described here by the adapter 220 which adapts the transition threshold, and by the power manager 230 which sends this information to the control card of the electrical generation source (respectively to the control cards of the electrical generation sources). Still as a variant, the switch to the silent state could not be purely manual,but take into account the environment of the aircraft 2, for example take into account one or more parameters among the flight height and a geographical location. The adapter 220 is arranged to receive the status data from the detector 200. On this basis the adapter 220 can determine a fault status and a corresponding emergency electrical configuration. For example, if the status data received from the detector 200 indicates that the engine 52 has failed, then the adapter 220 determines that the vertical drive group 10 must be isolated, and it returns an electrical configuration indicating the need for this isolation and to switch off the elements that it comprises. The adapter 220 thus contains a table of all the possible fault configurations, and the emergency electrical configuration corresponding to each. Similarly, if the adapter 220 determines that no fault is occurring,then it can return a nominal electrical configuration which can for example take into account the flight phase of the aircraft 2. The fact that the adapter 220 contains a table with all the possible failure configurations aims to guarantee any error. Alternatively, the adapter 220 could operate from logic operations in order to determine the emergency electrical configuration. In practice, the electrical configuration, whether nominal or emergency, reflects the fact that isolation switches and / or extinguishing controls must be activated. Indeed, each element of the circuit of figure 1 is connected to the rest of the circuit by a switch (not shown), and the consumers and producers of energy are furthermore controlled to switch on or off. If we take the example of the failure of the engine 52,then the adapter 220 determines a backup electrical configuration that isolates the vertical drive group 10 as shown in Figure 4. This results in a backup electrical configuration that indicates that all switches within the vertical drive group 10, i.e., the switch between the AC to DC converter 104 and the input of the vertical drive group 10 connected to the DC to AC converter 62, the switch between the AC to DC converter 106 and the input of the vertical drive group 10 connected to the DC to AC converter 64, the switch between the battery 50 and the rest of the vertical drive group 10,and a shutdown command for the engines 52 and 54. This emergency electrical configuration also indicates that all switches within the vertical drive group 12 must be activated to switch power to this group, as well as the switch 28 which must switch to the vertical drive group 12. The power manager 230 receives on the one hand the state of the automaton 210, and on the other hand the electrical configuration of the adapter 220. On this basis, the power manager 230 can control the stored electrical energy sources 50, 60, 80 and 90 and / or the electrical generation sources 18 and 20 according to the energy regime corresponding to the state of the automaton 210 and shutdown information indicated by the electrical configuration of the adapter 220. For example, in the takeoff phase, with the silent state activated,the power manager 230 sends a command to switch off the electrical generation sources 18 and 20. By switching off, it must be understood that the power manager 230 issues a command to electrically disconnect the elements considered from the electrical system. In practice, this command can result in a so-called “super idle” regime where the energy sources concerned run at a hyper-idle regime, which avoids switching them off for safety reasons (risk of restart problem). Still as a variant, this switching off can result in an electrical switching off in the literal sense of the term: - in the takeoff phase, with the state of charge, the power manager 230 sends a command to increase the power of the electrical generation sources 18 and 20 to reduce the power emitted by the batteries 50, 60, 80 and 90 to 0, - in the takeoff phase, with the turbo state,the power manager 230 sends a command to increase the power of the electrical generation sources 18 and 20 to their maximum capacity, - in the cruise flight phase, with the charge state, the power manager 230 sends a command to increase the power of the electrical generation sources 18 and 20 until the power emitted by the batteries 50, 60, 80 and 90 is equal to the inverse of the recharge power indicated by the BMS (i.e. in practice the batteries receive this recharge power), - in the cruise flight phase, with the buffer state, the power manager 230 sends a command to increase the power of the electrical generation sources 18 and 20 to lower the power emitted by the batteries 50, 60, 80 and 90 to 0, - in the descent phase, with the buffer state,the power manager 230 sends a command to increase the power of the electrical generation sources 18 and 20 to reduce the power emitted by the batteries 50, 60, 80 and 90 to 0, - in the landing phase, with the buffer state, the power manager 230 sends a command to increase the power of the electrical generation sources 18 and 20 to reduce the power emitted by the batteries 50, 60, 80 and 90 to 0, - in the landing phase, with the turbo state, the power manager 230 sends a command to increase the power of the electrical generation sources 18 and 20 to their maximum capacity, etc. The switch 240 is arranged to perform a binary AND type operation between, on the one hand, the configuration emitted by the adapter 220, and on the other hand, the electrical configuration induced by the state of the automaton 210. Thus, if we take the example of the breakdown of the motor 52,while the state of the automaton 210 is the turbo state, then, for the switches of the vertical drive group 10, this operation will be 0 (from the isolation controlled by the emergency electrical configuration emitted by the adapter 220) x 1 (from the turbo state) which will return 0 for these switches. Once the state of all the switches in the circuit has been determined by the switch 240, the corresponding commands are sent to all the switches in the circuit, and the loop from the detector 200 can resume. Thus, it appears that: - all the elements of the circuit consuming or producing power are connected to the detector 200 to indicate their state, - all the elements of the circuit which supply power are controlled by the power manager 230, - all the switches and on / off commands are controlled by the switch 240. Thus,the energy management system of the invention completely separates the management of the power production mode (via the automaton 210) and the management of the electrical configuration of the circuit to consume this power (via the adapter 220). The power manager 230 and the switch 240 are elements of a deliberately simplified nature so as to each receive the outputs of the automaton 210 and the adapter 220 and to be able to take these outputs into account to control the power suppliers and the switches respectively. This decorrelation of the control of the electrical circuit is particularly innovative and interesting in that it establishes an architecture that can be deployed quickly and reliably on all types of hybrid aircraft, regardless of the redundancy of their design. Finally, the load control device 250 receives information from the automaton 210 and the adapter 220,and transmits data to the power manager 230 and the switch 240. The role of the charge control device 250 is to interact with the various energy management elements in the aircraft 2 in order to manage the recharging of the stored electrical energy sources, and in particular to allow grouped recharging (or "pooled charging" in English). Although the charge control device 250 can be advantageous, as will be seen below, it nevertheless remains optional for the implementation of the invention. Figure 5 represents an example of implementation of the charge control device 250. The charge control device 250 comprises a matcher 500, one or more supervisors 510 to 51n and a charge parameter calculator 520. The respective roles of these elements are as follows: - the matcher 500 has the function of creating tuples associating at least two stored electrical energy sources with an electrical generation source,- each tuple is transmitted to a supervisor 510 to 51n. There are therefore as many supervisors as there are tuples. In practice, there will generally be as many supervisors as there are active electrical generation sources. Each supervisor has the function of determining, from a state machine and the data received from the automaton 210 and the adapter 220, the optimal load configuration of the electrical energy sources stored by the electrical generation source of its triplet, and - the load parameter calculator 520 is arranged to receive the load configurations from each of the supervisors,and to send back the necessary control data to the power manager 230 and the switch 240. The charge control device 250 which is the subject of the invention is thus based on the combination of three principles which allow coupled in-flight charging while ensuring redundancy and preventing the creation of a SPOF: 1) the definition of charge groups which associate an electrical generation source and one or more sources of stored electrical energy to be recharged. 2) the control of the behavior of a charge group from state information of the aircraft and the elements of the charge group using a state machine whose control makes it possible to prevent any risk. 3) the grouping of the information from each charge group to return control and state information to the aircraft and control the charge. In the preferred embodiment, the pairer 500 is executed only once per flight,preferably before takeoff. To operate, the pairer 500 receives as input data a status indicator of each electrical generation source as well as a status indicator of each stored electrical energy source. Thus, the pairer 500 can associate each electrical generation source with two stored electrical energy sources to form a load group each time. In the case where one or more stored electrical energy source status indicators indicate unavailability, the pairer 500 may be required to associate only one stored electrical energy source with an electrical generation source. Alternatively, more than two stored electrical energy sources may be associated with a load group. Once the load groups have been determined,these are each transmitted to a respective supervisor 510 to 51n. This transmission can be done in the form of a software instantiation of a supervisor for each load group, or by transmitting the load group as an execution variable to a supervisor. Furthermore, in the example described here, the matcher 500 is executed only once for each flight, preferably before takeoff. This means that once the load groups are defined, they do not change until the next flight. Alternatively, the matcher 500 could be executed regularly during flights, or when a particular event occurs. It may then be useful for the matcher 500 to receive as additional input data such event data (for example, the recovery or loss of one or more sources of stored electrical energy, charging prohibition information, or the like). In the case of the embodiment described here,the state determined by the automaton 210 could for example be useful. In the embodiment described here, each supervisor 510 to 51n receives as input data: a current state of the state machine, an aircraft grouped load indicator, a state indicator and a current intensity indicator of the electrical generation source of its load group, a load indicator, a voltage indicator and an indicator of maximum power available for each stored electrical energy source of its load group. These various inputs make it possible to determine several transition conditions between the various states of the state machine. The state machine has in the example described here the following states: a stop state, a wait state, a unit precharge state, a unit charge state, a grouped precharge state, a coupling state and a grouped charge state. In the stop state,the supervisor is stopped. This may be the case, for example, because the status indicator of the electrical energy generation source indicates a failure, or because one or more sources of stored electrical energy indicate a failure. The standby state is the basic state of the supervisor, and a necessary transition from a state associated with a unit load to a state associated with a grouped load. The unit precharge state is a state through which the supervisor must pass from the standby state before implementing the unit charge state. This state ensures a unit charge mode for the load group when the sources of stored electrical energy have significantly different charge levels. The unit charge state is a state in which one of the sources of stored electrical energy is recharged. This may be necessary when only one of the sources of stored electrical energy in a load group needs to be charged,or when the voltage level of one of the stored electrical energy sources needs to be brought back to a level high enough to allow group charging. The group precharge state is a state that the supervisor must pass through from the standby state before implementing the group charging state. This state ensures that the stored electrical energy sources in the load group have charge levels close enough to implement a group charging mode. The coupling state is a state that precedes the group charging state and is necessarily preceded by the group precharge state. This state is used to ensure the electrical paralleling of the stored electrical energy sources within a given load group. Finally,the group charging state is a state in which several sources of stored electrical energy are recharged simultaneously by the electrical generation source of the charging group to which they belong. The transition from the standby state to the unit precharge state may for example be caused by a group charging indicator of the aircraft being set to zero (i.e. prohibiting group charging), as well as a status indicator and a current intensity indicator of the electrical generation source indicating that power is available, while the charge indicator of at least one of the sources of stored electrical energy indicates that charging is possible (e.g. in a binary manner or because the charge indicator is below a charging threshold). The transition from the unit charging state to the standby state may be caused by receiving a group charging indicator from the aircraft which indicates that group charging is possible,or by the fact that the charge indicator of a stored electrical energy source being charged indicates that charging is no longer possible. Thus, each supervisor is arranged to determine at regular intervals a new current state of the state machine from the input data, as well as a direct current setpoint for each stored electrical energy source of its charging group. The determination of the direct current setpoint makes it possible to process in a completely passive manner, without any need for software or hardware intelligence other than their BMS. Preferably, each supervisor is arranged to simulate the operation of the BMS of the stored electrical energy sources of its storage group in order to leave no processing to the latter. This makes it possible in particular to control the charging method, which can be advantageously based on the CC-CV model, i.e. that initially,the stored electrical energy source is charged at constant current (hence the direct current setpoint), until a chosen voltage level is reached in the stored electrical energy source. In a second step, the charging continues this time at constant voltage, until the current indicates that the charging is finished. This charging paradigm is well known and fits particularly well into the state machine described for the supervisors. Once each supervisor has updated its current state and the direct current setpoint of each stored electrical energy source, these are transmitted to the charging parameter calculator 520 which will produce two parameter structures, one of which is intended for the aircraft management system and the other for the BMS of the stored electrical energy sources. In the embodiment described above, the first structure is sent to the switch 240,while the second structure is sent to the power manager 230. In the example described here, the first structure thus comprises a matrix of the load groups, which makes it possible both to organize the electrical switching to direct the electric current coming from the sources of electrical generation to the sources of stored electrical energy paired by the pairer 500 and on the other hand a charging mode vector which indicates for each load group whether it is in unit charging (and in this case on which source of stored electrical energy), in grouped charging, or on standby. In the example described here, the second structure comprises the concatenation of five BMS control values ​​of each source of stored electrical energy: - the constant current setpoint (used for the CC charging mode), - the constant voltage setpoint (used by the CV charging mode), - a charging stop indicator, - a charging trigger indicator,and - the end-of-charge current threshold. Conventionally, the charge stop indicator takes precedence over all other data. Thus, if the current state of the state machine is a unit or coupled charge and the charge stop indicator is activated by the BMS of the stored electrical energy source concerned, whether for a fault or other reason, the state machine will automatically go into the waiting state. The charge trigger indicator is for its part activated in a conventional manner when the charge stop indicator is deactivated and the unit precharge state or the coupling state is activated and the state machine determines that unit charge or grouped charge is now possible. It is clear from the above that the different states of the state machine make it possible to very finely divide each stage of charging, in a grouped manner or not,of a stored electrical energy source. This results in securing the charge control device 250 which can at any time control the state of charge and guarantee the charge in flight, optimized for each stored electrical energy source, or even grouped, and without risk of SPOF. The paradigm described above is particularly advantageous because it allows, from a highly generalist architecture, to adapt the charge control device to a very large number of implementations, without having to recreate the architecture. Indeed, in the embodiment described above, the aircraft is a VTOL whose EMS itself implements a state machine. Also, the charge control device 250 integrates naturally into the energy management system 4. Nevertheless, it appears that the charge control device 250 could be integrated as a separate module in any hybrid aircraft,since it receives global information from the aircraft (such as failures, flight phases prohibiting recharging, instantaneous states of the elements, etc.) and the latter can receive its information to implement the recharging command. In addition, its architecture offers great flexibility: if the electrical generation sources are connected to only some of the stored electrical energy sources, then the matcher will perform an association constrained by this physical reality, but if this is not the case, it could for example be envisaged to regularly execute the matcher in order to modify the load groups to associate the stored electrical energy sources whose voltage levels are closest. Still as a variant, although the load groups described here each contain at most two stored electrical energy sources,This number can be increased. Defining load groups allows supervisors to be instantiated according to the needs identified by the matcher. This means that the consumption of computing resources can be optimized by activating only the supervisors that are necessary. Similarly, the separation between supervisors and the load parameter calculator allows for the separation of processing and therefore prevents the risk of SPOF. For example, if a supervisor does not respond,the charging parameter calculator can continue to operate with the other charging groups and signal to the aircraft management system that there is a potential problem for the charging group associated with this supervisor. The charging control device according to the invention therefore offers an algorithm using a state machine making it possible to carry out a sequencing of the charging of the batteries associated in a charging group until they are brought back to a voltage level difference deemed acceptable, then a paralleling of these batteries to carry out a grouped charging (or "pooled charging") of these batteries. Beyond the possibility of grouped charging, the invention not only makes it possible to offer the most flexible in-flight battery charging strategy possible, but also to guarantee the possibility of in-flight charging at all,which is not known to date when the absence of SPOF must be guaranteed. The implementation of the in-flight recharge control device is also advantageous because it allows better preparation for the risks associated with failures during descent. Indeed, in normal times, the stored electrical energy sources tend to discharge asymmetrically. Indeed, as seen above, the electrical architecture is divided into four (or more) groups which are separated during normal operation to ensure safety during flight. Each group has a dedicated battery which constitutes the main source of energy supply. This separation makes it possible to tolerate a single failure during vertical operation. In addition, the operation of the aircraft gives rise to heterogeneous flight phases. Takeoff and landing are carried out in vertical mode with 8 engines of the vertical drive group. During conventional flight operations,other electric motors are used. This heterogeneous distribution of power consumption over the entire flight leads to imbalances in the battery charge state. In the event of a single failure, it is desirable to balance and use all the remaining energy by connecting the remaining battery packs in parallel. However, as seen above, the consumption by these battery packs may not have been balanced between the groups. However, parallel connection is only possible if the voltage differences between the battery packs are below a certain threshold. If the voltage differences are too large, the charging current entering the least charged batteries will exceed the operational limits of the batteries. In order to better understand this phenomenon,Figure 6 shows an electrical diagram explaining the pooling of two stored electrical energy sources. In the example shown in Figure 6, the two stored electrical energy sources are source 50 and source 60 of the embodiment of Figure 1. From an electrical point of view, the stored electrical energy source 50 (respectively 60) can be seen as the combination of a voltage source 550 (respectively 650) and a resistor 560 (respectively 660) which supply an electrical load represented by a current source 570 (respectively 670). The stored electrical energy source 50 and the stored electrical energy source 60 are electrically connected by a pooling switch 600 which, if closed, connects the circuit formed by the voltage source 550, the resistor 560 and the current source 570, and, if open, opens it. Thus, if the pooling switch 600 is closed,the stored electrical energy sources 50 and 60 are pooled, whereas if it is open, they are independent from an electrical point of view. As explained above, in normal operation of the aircraft, pooling is normally not desired, in order to avoid the risks of SPOF. Also, the question of pooling particularly concerns the transition from "no pooling" to "pooling". In what follows, each physical quantity (V for voltage, I for intensity, R for resistance and IL for the intensity of the current source) receives an index ("50" or "60") corresponding to the electrical energy source to which it corresponds. When closing the pooling switch 600, if the voltage V50 of the voltage source 550 is different from the voltage V, 60of the voltage source 650, this will induce a change in the intensity circulating in the stored energy source whose voltage is the lowest. Indeed, when the pooling switch 600 is closed, we have: It appears that, if the difference between voltage V50 and voltage V60 is too large, one of the two sources of stored electrical energy will receive a current likely to damage it. The value of the maximum tolerable current is here called Imax (presumed positive by convention). Depending on the sign of V 50 – V 60 , so we have Therefore, still depending on the sign of V50 – V60, it is only possible to close the pooling switch 600 without risk if ^^^ − ^^^^ ^^^^^^( ^^^ + ^^^) + ^^^(^^^^ + ^^^^) or ^^^ − ^^^^ ^^^^^^( ^^^ +^^^) + ^^^(^^^^ + ^^^^)Of course, the example of Figure 6 can be generalized for other sources of stored electrical energy, as well as for the pooling of more than two sources of stored electrical energy. Therefore, in the event of a failure, before the switch 240 commands the closing of the pooling switch 600, the power manager 230 must ensure that the voltage difference between the sources of stored electrical energy is lower than the limit values ​​expressed above.Thus, in the event of a failure and determination by the adapter 220 of a backup electrical configuration involving pooling of several stored electrical energy sources, the power manager 230 begins by checking whether the voltage levels of the stored electrical energy sources are compatible with pooling. If this is the case, then the pooling switch(es) concerned are closed by the switch 240. If this is not the case, then the energy management system can implement one or more of the following strategies: - if the stored energy sources cannot be pooled, including two by two, a sequential charge is implemented by prioritizing the available stored energy sources having the lowest voltage levels. The goal is to raise the voltages of these stored energy sources until each can be paired with another stored electrical energy source.- if several sources of stored electrical energy can be paired two by two, but not three by three, the pooling of the sources of electrical energy having the lowest charge level is preferred. - if two sources of stored electrical energy can be pooled, but not the third, these two sources are pooled, and the recharging of the third is adapted to allow the fastest possible pooling with the other two. - if more than two sources of electrical energy must be pooled, this pooling is nevertheless carried out in several stages, by closing a single pooling switch each time. In the context of the implementation of the invention, the Applicant has discovered that it is advantageous to use the in-flight recharging device 250 in order to pool the batteries two by two as soon as the aircraft is in conventional flight mode.In this configuration, the aircraft remains tolerant to a single failure because a single engine is sufficient. On the other hand, as soon as the aircraft switches from conventional flight mode to a vertical flight mode, the shared recharging of the batteries must be deactivated in order to preserve the tolerance to a single failure. Thus, the power manager 230 can be arranged to detect a transition from a vertical flight phase to a horizontal flight phase, and to activate in this case the grouped recharging of batteries in groups of two. Thus, the batteries will have similar voltage levels, which will allow them to be grouped in the event of loss of a battery during a vertical flight phase. In addition, the power manager 230 can be arranged to detect a transition from a horizontal flight phase to a vertical flight phase and to cut off the grouped recharging in order to guarantee flight safety.It should be noted that, during the transition from vertical to horizontal flight, all motors are activated. This means that the states of charge between the different battery packs can be quite different after this transition phase. However, paralleling the packs in this situation is beneficial, as the current that will naturally flow from one battery to the other will tend to recharge the most discharged battery, and therefore bring the batteries back to similar states of charge more quickly, until the group charge can be fully achieved. The ability to harmonize the battery voltage levels is particularly interesting because it allows for many types of reconfiguration during a flight in the event of a failure.Indeed, the architecture of Figure 4 can be extended to create electrical groups each associating a source of stored electrical energy, a source of electrical generation, two rotor motors (for vertical drive) and a thruster motor (for horizontal drive). The pooling of the stored electrical energy sources can be achieved by allowing each vertical drive group 6 and 8 to be connected simultaneously to two batteries.For example, a matrix of these electrical groups may be as follows (using the references in Figure 4): Motor Motor Motor Battery Turbogenerator Propellant Rotor #1 Rotor #2 Group A 24 50 52 54 100 Group B 24 60 56 58 100 Group C 34 80 82 84 102 Group D 34 90 92 94 102 According to this distribution: - the propellant motor 24 is powered 50% by group A and 50% by group B, - the propellant motor 34 is powered 50% by group C and 50% by group D, - the rotor motors 52 and 54 are powered by group A, - the rotor motors 56 and 58 are powered by group B, - the rotor motors 82 and 84 are powered by group C, and - rotor motors 86 and 88 are powered by group D. This configuration can be particularly interesting with a distribution of batteries, turbogenerators and motors as illustrated in figure 7.It is recalled that the architecture is optimized to withstand the failure of a single electrical energy storage or generation element and allow a normal end of flight, i.e. without an emergency landing procedure. In the event of failure of an element, it is therefore useful to be able to group the remaining elements together to form a single electrical group. This is all the faster and easier if the batteries have similar voltage levels. For example, in the case where battery 50 experiences a failure, for example a short circuit, this means that there are three batteries and two turbine generators remaining to provide electrical energy until the end of the flight. The thruster motor 24 can still be powered by group B, but the rotor motors 52 and 54 are, however, lost because they can no longer be powered because group A will be isolated from the rest of the aircraft.By implementing the invention using the in-flight charging control device 250, there is a significant chance that the three remaining batteries will have voltage levels close enough that a so-called "pooled 3-2" backup configuration can be implemented immediately. In this configuration, the batteries 60, 80 and 90 as well as the turbogenerators 100 and 102 are pooled in order to be able to provide electrical energy to the thruster motors 24 and 34, as well as to the rotor motors 56, 58, 82, 84, 86 and 88.If for some reason one of the batteries has a voltage level too far from the other two (since the batteries were recharged in pairs before the failure, at least two batteries have a similar voltage level, but it remains possible that the third is far away), the third battery is recharged alone until the "pooled 3-2" configuration can be implemented, or conversely it is expected that it has a charge similar to that of the other two batteries to be associated with them. Still in this same configuration, if the short circuit generates a protection of the turbogenerator 100. However, in this case, the battery 60 of group B has already been grouped with the batteries 80 and 90 and the turbogenerator 102. Also, it is sufficient to launch a reset procedure of the turbogenerator 100, which takes a few seconds, and the "pooled 3-2" configuration becomes operational again.In this case, the implementation of the invention is even more advantageous, because it makes it possible to group the battery 60 with the batteries 80 and 90, which secures the restart procedure of the turbogenerator 100. If it is the battery 60, 80 or 90 that fails, the "pooled 3-2" configuration applies in a similar manner, but obviously by changing the elements concerned. Another failure case concerns the case where it is one of the two turbogenerators that fails, for example the turbogenerator 100. In this case, all the rotor motors and all the thruster motors can still be powered, because the isolation of the turbogenerator 100 will not prevent the power supply to the latter (unlike the rotor motors during the previous failure case).Thanks to the invention, it is then possible to implement a so-called "pooled 4-1" backup configuration in which the four batteries 50, 60, 80 and 90 are grouped together and with the remaining turbogenerator 102. Here again, the grouped charging of the batteries allows a faster transition to the backup configuration. In general, it therefore appears advantageous to have pooling switches making it possible to connect the stored electrical energy sources and the electrical generation sources together, in order to provide optimal energy capacity in the event of an in-flight failure.

Claims

Claims

1. Energy management system for an aircraft with a hybrid energy source comprising at least three stored electrical energy sources and an electrical generation source, comprising: - a detector (200) arranged to determine on the one hand state data indicating a state of the elements of the electrical power consumption circuit of the aircraft controlled by the energy management system, and on the other hand energy data relating to the instantaneous electrical power requested by the aircraft and / or the current of the stored electrical energy sources of the aircraft, and / or the charging state of the stored electrical energy sources of the aircraft, - an automaton (210) arranged to receive the energy data from the detector (200) and to determine a control state of the energy sources,the automaton (210) comprising at least three states in the group comprising: * a buffer state in which the instantaneous electrical power requested is less than the capacity of the electrical generation source(s) and is supplied by the latter, * a charging state in which the instantaneous electrical power requested is less than the capacity of the electrical generation source(s) and is supplied entirely by the electrical generation source(s), and in which the electrical generation source(s) produces a surplus of power used to recharge the stored electrical energy source(s), * a turbo state in which the instantaneous electrical power requested is greater than the capacity of the electrical generation source(s), and where the stored electrical energy source(s) provides the supplement necessary to reach the instantaneous electrical power requested,- an adapter (220) arranged to receive the status data and to determine a backup electrical configuration when the status data indicates a failure, - a power manager (230) arranged to receive the status information from the automaton (210) and to determine an electrical command for the stored electrical energy source(s) (50, 60, 80, 90) and the electrical generation source(s) (18, 20), and - a switch (240) arranged to issue commands to the switches of the electrical power consumption circuit of the aircraft controlled by the system, power management to implement a nominal electrical configuration, or, in case of reception of a backup electrical configuration of the adapter (220), this backup electrical configuration, characterized in that the power manager (230) is further arranged, in the presence of a backup electrical configuration indicating the pooling of two or more sources of stored electrical energy, to determine whether the voltage levels of said two or more sources of stored electrical energy allow this pooling, and the switch (240) being arranged to implement said pooling of two or more sources of stored electrical energy if the determination by the power manager (230) is positive,the energy management system further comprises an in-flight recharging control device (250) arranged to communicate with the power manager (230) and the switch (240) to control the recharging of the stored electrical energy sources of the aircraft in a grouped manner, the power manager (230) is further arranged to detect a transition between a vertical flight phase and a horizontal flight phase, and to communicate with the in-flight recharging control device (250) and the switch (240) in order to control the recharging of the stored electrical energy sources of the aircraft in a grouped manner upon detection of a transition from a vertical flight phase to a horizontal flight phase, and to deactivate the recharging of the stored electrical energy sources of the aircraft in a grouped manner upon detection of a transition from a horizontal flight phase to vertical flight.

2. The system of claim 1, wherein,when the determination by the power manager (230) is negative, the system is arranged to implement one or more of the following strategies: - when said two or more stored energy sources cannot be pooled, the energy system implements a sequential charge by prioritizing the stored energy sources among said two or more stored electrical energy sources having the lowest voltage levels, - when some of the stored electrical energy sources among said two or more stored electrical energy sources can be pooled, but less, as indicated by the emergency electrical configuration, the energy management system pools poolable stored electrical energy sources having the lowest charge level, - if two stored electrical energy sources among said two or more stored electrical energy sources can be pooled but not a third, these two stored electrical energy sources are pooled, and the energy management system recharges the third in a manner adapted to allow the fastest possible pooling with the other two, - if more than two electrical energy sources among said two or more stored electrical energy sources are to be pooled, the energy management system carries out the pooling in several stages,first by pooling two sources of stored electrical energy and then adding each time a source of stored electrical energy.

3. System according to claim 1 or 2, in which the at least two sources of stored electrical energy each associated with at least one electrical switch, and in which the in-flight charging control device comprises - a matcher (500) arranged to receive a state indicator of each source of electrical generation as well as a state indicator of each source of stored electrical energy, to determine one or more load groups each associating a source of electrical generation with two sources of stored electrical energy, and to transmit each load group to a respective supervisor (510,51n), - each supervisor (510,51n) being arranged to implement a state machine chosen from the group comprising a stop state, a wait state, a unit precharge state,a unit load state, a group precharge state, a coupling state and a group load state, to retrieve input data including a current state of state machine, an aircraft group load indicator, a state indicator and a current intensity indicator of the electrical generation source of its load group, a load indicator, a voltage indicator and an indicator of maximum power available for each source, of stored electrical energy from its load group, to determine a new current state of the state machine from the input data, as well as a direct current setpoint for each stored electrical energy source of its load group, and to transmit the new current state of the state machine and the direct current setpoints to a load parameter calculator, - the load parameter calculator (520) being arranged to determine, for each stored electrical energy source, a direct voltage setpoint, a direct current to direct voltage transition setpoint, a load stop indicator and a forced load indicator from the current state of the state machine and the direct current setpoints of each supervisor as well as an opening or closing setpoint for the electrical switches associated with the stored energy sources to allow electrical grouping thereof.

4. The system of claim 3, wherein each supervisor (510, 51n) is software instantiated based on the transmission by the pairer (500).

5. The system of claim 3, wherein the supervisors are always available, and wherein the call by the pairer (500) creates a link between each supervisor (510, 51n) and a load group.

6. The system of one of claims 3 to 5, wherein the pairer (500) is arranged to determine one or more load groups comprising more than two sources of stored electrical energy.

7. The system of one of claims 3 to 6, wherein the pairer (500) is arranged to access load groups that are defined for an operating time of the device corresponding to a flight.

8. System according to one of claims 3 to 7, wherein the matcher (500) is arranged to determine the load groups dynamically.

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