ENERGY SUPPLY IN AN AIRCRAFT USING DROOP CONTROL

Description

Technical field of the invention

[0001] The present invention relates to an aircraft power supply installation, an aircraft comprising such an installation, and a corresponding method. Technological background

[0002] It is known from the prior art to provide, in an aircraft, a power supply system of the type comprising: a continuous bus to which at least one electrical load is intended to be connected; several electrical sources including: at least one so-called low-pressure electrical source designed to draw power from a low-pressure body of a turbomachine of the aircraft, in order to supply current to the continuous bus, and at least one so-called high-pressure electrical source designed to draw power from a high-pressure body of the turbomachine of the aircraft, in order to supply current to the continuous bus.

[0003] It may be desirable to provide a robust electrical source regulation system that does not significantly interfere with the operation of the turbomachine.

[0004] For example, document GB 2510121 A1 describes frequency or voltage drastic regulation with a master / slave system. Summary of the invention

[0005] Therefore, a power supply installation for an aircraft, of the aforementioned type, is proposed, characterized in that it further comprises: a system for calculating a drastic gain for each low-pressure electrical source and each high-pressure electrical source, from at least one operating characteristic of the turbomachine; and for each low-pressure electrical source and each high-pressure electrical source, a control module for the electrical source in question, designed to implement drastic regulation from the drastic gain calculated for the electrical source in question.

[0006] Thanks to the invention, it is possible to implement decentralized control, that is, control independent of one electrical source to another. Thus, the control is robust to the loss of one of the sources. Furthermore, the fact that the droop gains are calculated from at least one operating characteristic of the turbomachine allows them to be defined in accordance with the desired operating point, so that the control does not significantly interfere with the turbomachine's operation.

[0007] An energy supply installation according to the invention may further include one or more of the following optional features, in any technically possible combination.

[0008] Optionally, at least one operating characteristic of the turbomachine includes at least one of the following: a fuel inlet flow rate and / or an air inlet flow rate into a combustion chamber of the turbomachine, a low-pressure body rotation speed, a high-pressure body rotation speed, an air inlet temperature and / or fuel inlet temperature and / or exhaust gas exiting the combustion chamber.

[0009] Optionally, the static gain calculation system also includes: - a turbomachine controller designed to define a ratio between the power taken from the high-pressure body by the high-pressure electrical source(s) and the power taken from the low-pressure body by the low-pressure electrical source(s), based on the operating characteristic(s) of the turbomachine; and - for each electrical source, a calculation module, based on the ratio, of the static gain of the electrical source considered, so that the ratio is respected.

[0010] Optionally, the controller is also designed to provide so-called power data representative of a maximum low-pressure mechanical power that can be taken from the low-pressure body and a maximum high-pressure mechanical power that can be taken from the high-pressure body, and each calculation module is designed to calculate the associated drastic gain from the power data, so that the mechanical power taken from the low-pressure body remains less than or equal to the maximum low-pressure mechanical power and the mechanical power taken from the high-pressure body remains less than or equal to the maximum high-pressure mechanical power.

[0011] Optionally, each calculation module is also designed to calculate the associated drastic gain in order to maximize a sum of the currents that can be supplied respectively by the electrical sources, when the DC bus has a minimum bus voltage predefined by the drastic regulation.

[0012] Optionally, the installation also includes several high-pressure electrical sources and / or several low-pressure electrical sources, and the calculation module for each high-pressure, or low-pressure, electrical source is designed to calculate the associated drastic gain from a ratio between, on the one hand, the current supplied by the high-pressure, or low-pressure, source considered and, on the other hand, a sum of the currents supplied by all the high-pressure, or low-pressure, electrical sources respectively.

[0013] Optionally, each calculation module is also designed to calculate the static gain of the high-pressure electrical source as the product of the ratio by a constant and the static gain of the low-pressure electrical source as the product of the complement to one of the ratio by the constant.

[0014] Optionally, each control module is also designed to: - calculate a reference current from the associated droop gain; - calculate, from the power data, a maximum current that can be supplied by the associated power source; and - limit the reference current to the maximum current.

[0015] An aircraft comprising an installation according to the invention is also proposed.

[0016] A method for supplying energy in an aircraft is also proposed, characterized in that it comprises: - the calculation, from at least one measurement of at least one operating characteristic of a turbomachine, of a droop gain for: each so-called low-pressure electrical source designed to extract power from a low-pressure body of the aircraft's turbomachine, in order to supply a current to a DC bus to which at least one electrical load is intended to be connected, and each so-called high-pressure electrical source designed to extract power from a high-pressure body of the aircraft's turbomachine, in order to supply a current to the DC bus; and - for each low-pressure electrical source and each high-pressure electrical source, the implementation of a droop control based on the droop gain calculated for the electrical source in question. Brief description of the figures

[0017] The invention will be better understood with the aid of the following description, given solely by way of example and made with reference to the accompanying drawings in which: there figure 1 is a simplified view of an installation according to the invention for supplying power in an aircraft, the figure 2 is a functional view of control modules for two electrical sources respectively coupled to a low-pressure and a high-pressure body of a turbomachine, to supply currents to a DC bus, the control modules implementing drastic regulation, the figure 3 is a functional view of a drastic gain calculation module for the control module of the electrical source coupled to the low-pressure body, the figure 4 is a functional view of a drastic gain calculation module for the control module of the electrical source coupled to the high-pressure body, the figure 5is a curve illustrating the relationship between the gains in static stability to maintain a desired distribution between the mechanical power extracted from the low-pressure body and the mechanical power extracted from the high-pressure body, in a first operating case, the figure 6 illustrates the currents supplied by the electrical sources as a function of a DC bus voltage, in the first operating case, the figure 7 is a curve illustrating the relationship between the static gains required to achieve a desired distribution between the mechanical power drawn from the low-pressure body and the mechanical power drawn from the high-pressure body, in a second operating case, the figure 8 illustrates the currents supplied by the electrical sources as a function of the DC bus voltage, in the second operating case, the figure 9is a simplified view of another installation according to the invention for supplying power in an aircraft, with several electrical sources coupled to the high-pressure body, the Figure 10 is a functional view of a drastic gain calculation module for the control module of one of the electrical sources coupled to the high-pressure body, the figure 11 is a functional view of a calculation module for a static gain for the control module of the other electrical sources coupled to the high-pressure body, the figure 12 is a functional view of an alternative control module, the figure 13 is a functional view of an alternative module for calculating a static gain for the control module of the low-pressure coupled electrical source, the figure 14is a functional view of an alternative module for calculating a static gain for the control module of the electrical source coupled to the high-pressure body, and the figure 15 illustrates the currents supplied by the electrical sources as a function of the DC bus voltage, in the alternative of figures 12 to 14 . Detailed description of the invention

[0018] With reference to the figure 1 An example of a 100 power supply installation in an aircraft will now be described.

[0019] Installation 100 includes first of all a turbomachine 102 comprising a low pressure (LP) body 104 and a high pressure (HP) body 106. The turbomachine 102 is for example a propulsion turbomachine of the aircraft.

[0020] The installation 100 further includes a controller 108 for the turbomachine 102. This controller 108 is designed, for example, to regulate the fuel inlet flow rate and / or the air inlet flow rate in a combustion chamber of the turbomachine 102. To regulate the air inlet flow rate, the controller 108 controls, for example, the orientation of the stator blades of a high-pressure (HP) compressor 110 of the HP casing 106. The controller 108 is designed, for example, to make these adjustments based on at least one operating characteristic (measured and / or estimated, for example, from other measurements) of the turbomachine 102, for example, one or more of the following: the fuel inlet flow rate and / or the air inlet flow rate, a rotational speed of the LP casing 104, a rotational speed of the HP casing 106, an air inlet temperature and / or a fuel inlet temperature and / or an exhaust gas outlet temperature of the combustion chamber.

[0021] The controller 108 is further designed to define a power distribution ratio S between the LP and HP cylinders. This ratio S is generally called a "split" and expresses the proportion of mechanical power distributed from the HP cylinder 106 (or, alternatively, from the LP cylinder 104) relative to the mechanical power distributed from both the LP cylinder 104 and the HP cylinder 106. The split S is, for example, expressed as a percentage. The definition of the ratio S is based on at least one operating characteristic (measured and / or estimated, for example, from other measurements) of the turbomachine 102, for example, one or more of the following: the fuel inlet flow rate and / or the air inlet flow rate, the rotational speed of the LP cylinder 104, the rotational speed of the HP cylinder 106, the air inlet temperature and / or the fuel inlet temperature and / or the exhaust gas temperature exiting the combustion chamber.The controller 108 is for example designed to define the split S from a look-up table associating values ​​of the operating characteristic(s) of the turbomachine 102 with values ​​of the split S.

[0022] Preferably, the controller 108 is also designed to calculate so-called power data representative of a maximum mechanical power that can be extracted from the BP body, denoted PBPmax_meca, and a maximum mechanical power that can be extracted from the HP body, denoted PHPmax_meca. This power data may include, for example, the maximum powers PBPmax_meca and PHPmax_meca themselves, or the maximum torques CBPmax and CHPmax respectively supplied by the BP body 104 and the HP body 106.Power data are for example calculated from at least one characteristic (measured and / or estimated, for example from other measurements) of operation of the turbomachine 102, for example one or more of: a torque of an output shaft of the turbomachine 102, the rotational speed of the LP body 104, the rotational speed of the HP body, the inlet air temperature and / or fuel inlet temperature and / or exhaust gas temperature exiting the combustion chamber, the inlet air flow rate and / or fuel inlet, the inlet air pressure and / or fuel inlet, a torque supplied by the LP body 104 and a torque supplied by the HP body 106.

[0023] Installation 100 also includes a direct current bus 112 to which at least one electrical load 114 is intended to be connected. Each load 114 corresponds, for example, to one or more pieces of equipment on the aircraft.

[0024] Installation 100 also includes several electrical sources 116 BP, 116 HP, each designed to draw mechanical power from the turbomachine 102, in order to supply electrical power to the continuous bus 112.

[0025] These electrical sources 116 BP, 116 HP include in particular one or more electrical sources, designated as low pressure (LP), each designed to extract mechanical power from the LP body 104 of the turbomachine 102, in order to supply electrical power to the DC bus 112. On the figure 1 , installation 100 comprises a single BP electrical source, designated by the reference 116 BP .

[0026] The electrical sources 116 BP, 116 HP further include one or more electrical sources, designated as high-pressure (HP), each designed to extract mechanical power from the HP body 106 of the turbomachine 102, in order to supply electrical power to the DC bus 112. On the figure 1, installation 100 has a single HP electrical source, designated by the reference 116 HP.

[0027] For example, each 116 BP, 116 HP power source includes a generator followed by a rectifier.

[0028] Installation 100 further includes, for each electrical source 116 BP, 116 HP, a control module 120 BP, 120 HP for the electrical source 116 BP, 116 HP in question, specifically for its rectifier. Each control module 120 BP, 120 HP is designed to implement droop control based on a droop gain K BP, K HP associated with the electrical source 116 1, 116 2 in question.

[0029] Installation 100 also includes, for each electrical source 116 BP , 116 HP, a calculation module 122 BP , 122 HP, from the ratio S, of the static gain K BP , K HP for the electrical source 116 BP , 116 HP considered, so that the ratio S is respected.

[0030] In general, droop control involves allowing the DC bus 112 to exhibit a bus voltage UDC that can vary slightly between a nominal voltage UDC* and a minimum voltage UDCmin, which is lower than the nominal voltage UDC*, hence the term "sag". Furthermore, in droop control, each electrical source 116BP, 116HP is regulated to provide a current IBP, IHP proportional to the bus voltage drop ΔUDC (equal to UDC* - UDC), the associated droop gain KBP, KHP constituting the proportionality ratio: IBP = KBP · ΔUDC and IHP = KHP · ΔUDC

[0031] In this way, the regulation of the electrical sources 116 BP and 116 HP can be carried out independently of each other, but they remain coupled by the DC bus voltage U so as to reach an equilibrium point in which the contribution of electrical power supplied to the DC bus 112 by each electrical source 116 BP and 116 HP is defined by the droop gains KBP and KHP. By adjusting these gains, it is therefore possible to regulate the relative contributions of the electrical sources 116 BP and 116 HP.

[0032] For example, the supplied current IBP, IHP is regulated to follow a reference current IBP*, IHP* given by IBP* = KBP · ΔUDC and IHP* = KHP · ΔUDC. This implementation example will now be described with reference to the figure 2 .

[0033] In this example, each 120 BP, 120 HP control module has a 202 BP, 202 HP block for calculating the reference current I BP*, I HP* from the bus voltage U DC, the nominal bus voltage U DC* and the droop gain K BP, K HP.

[0034] Each control module 122 BP, 122 HP further includes a 204 BP, 204 HP block for comparing the supplied current IBP, IHP to the reference current IBP*, IHP* to provide a current error. Each control module 122 BP, 122 HP further includes a regulation block designed to provide commands to the power source 116 BP, 116 HP based on the current error. These commands aim to make the supplied current IBP, IHP equal to the reference current IBP*, IHP*, in other words, they aim to cancel the current error. Examples of such commands are pulse-width modulation (PWM) commands BP, PWM HP.

[0035] With reference to the figure 3 and to the figure 4 , an example of the implementation of the modules 122 BP , 122 HP for calculating the drowsiness gains K BP , K HP , will now be described.

[0036] Each module 122 BP, 122 HP includes, for example, a calculation block 302 for the maximum electrical power P BPmax, P HPmax that can be supplied by the associated electrical source 116 BP, 116 HP. Preferably, this maximum electrical power P BPmax, P HPmax takes into account the maximum mechanical power P BPmax_meca, P HPmax_meca that can be extracted, which is, for example, supplied by the controller 108 or calculated from the maximum torque supplied by the controller 108 and the rotational speed of the BP body 104, or the HP body 106 respectively, and / or a nominal power P BPmax_elec, P HPmax_elec of the electrical source 116 BP, 116 HP under consideration. For example, the maximum electrical power P BPmax , P HPmax is the minimum between the maximum mechanical power P BPmax_meca , P HPmax_meca that can be taken and the nominal power P BPmax_elec , P HPmax_elec of the electrical source 116 BP , 116 HP considered.

[0037] Generally, the rated power outputs PBPmax_elec and PHPmax_elec of the electrical sources 116 BP and 116 HP depend on their design and are fixed. In contrast, the maximum mechanical power outputs PBPmax_meca and PHPmax_meca that can be extracted generally depend on the operating point and the condition of the turbomachine 102 and therefore vary over time. Consequently, the maximum electrical power outputs PBPmax and PHPmax can also vary over time.

[0038] Each 122 BP, 122 HP module further includes a 304 block for calculating a maximum static gain K BPmax, K HPmax, enabling the associated 116 BP, 116 HP power source to deliver the maximum power P BPmax, P HPmax, especially when the bus voltage U DC is the minimum bus voltage U DCmin.

[0039] In general, the same ratio S can be obtained by several static gains K BP , K HP. Preferably, the modules 122 BP , 122 HP for calculating static gains K BP , K HP are designed to calculate these in order to maximize the sum of the currents I BP , I HP that can be supplied by the electrical sources 116 BP , 116 HP.

[0040] The maximum current IBPmax, IHPmax that can be supplied by each electrical source 116 BP, 116 HP is that supplied when the bus voltage UDC is equal to the minimum bus voltage UDCmin, that is, for a maximum voltage drop ΔUDCmax = UDC * - UDCmin. The maximum currents IBPmax, IHPmax that can be supplied are then given by: IBPmax = KBP · ΔUDCmax and IHPmax = KHP · ΔUDCmax. Thus, taking into account the calculated maximum powers PBPmax, PHPmax, the maximum droop gains KBPmax, KBPmax are given by: KBPmax = PBPmax / (ΔUDCmax · UDCmin) and KHPmax = PHPmax / (ΔUDCmax · UDCmin).

[0041] Furthermore, the ratio S is given by S = K HP / (K HP + K BP ). Thus, for a given ratio S, the static gains are related to each other by K BP = (1-S) / S · K HP .

[0042] With reference to figures 5 to 7It is easy to see that the sum of the supplied currents IBP, IHP is at its maximum when one of the droop gains HBP, KHP is at its maximum. To respect the maximum powers PBPmax, PHPmax, it is also necessary to ensure that the other droop gain KBP, KHP is well below (or equal to) its maximum. Regarding the example of Figures 5 And 6 It is the static gain KHP that can reach its maximum KHPmax, with the other static gain KBP being less than its maximum KBPmax. The static gain KBP is then equal to KBP = (1-S) / S · KHPmax. In the example of figures 7 And 8 , it is the static gain K BP which can reach its maximum K BPmax , with the other static gain K HP less than its maximum K HPmax . The static gain K HP is then equal to K HP = S / (1-S) · K BPmax .

[0043] Thus, each of the 122 BP, 122 HP modules also includes a block 306 designed to determine whether the drastic gain K BP, K HP to be supplied should be taken at its maximum or not. For example, the block 306 of each 122 BP, 122 HP module is designed to determine whether the drastic gain K BP, K HP to be supplied is less than its maximum K BPmax, K HPmax, assuming the other drastic gain is at its maximum. Thus, the block 306 of the 122 BP module checks, for example, whether (1-S) / S · K HPmax is less than K BPmax, while the block 306 of the 122 HP module checks, for example, whether S / (1-S) · K BPmax is less than K HPmax. Alternatively, other equivalent inequalities could be used.

[0044] If block 306 determines that the static gain K BP , K HP to be supplied must be taken at its maximum, each module 122 BP , 122 HP is designed to supply the static gain K BP , K HP at its maximum K BPmax , K HPmax .

[0045] Otherwise, each 122 BP, 122 HP module is designed to calculate the static gain K BP, K HP to be provided from the ratio S and the other static gain K BP, K HP, taken at its maximum K BPmax, K HPmax.

[0046] With reference to the figure 9 , another example of a 900 power supply installation in an aircraft, will now be described.

[0047] Installation 900 is similar to installation 100 of the figure 1 The only difference is that it comprises several high-pressure electrical sources instead of just one—two in the example described—designated by the references 116 HP1 and 116 HP2. Overall, these two high-pressure electrical sources, 116 HP1 and 116 HP2, behave like the single high-pressure electrical source 116 HP of the figure 1 .

[0048] The 900 installation thus includes, for each high-pressure electrical source 116 HP1, 116 HP2, a control module 120 HP1, 120 HP2 and a module 122 HP1, 122 HP2 for calculating the respective static gain K HP1, K HP2.

[0049] In this case, with reference to the Figure 10 and to the figure 11 Each module 122 HP1, 122 HP2, for example, uses a respective secondary ratio s1, s2. Each secondary ratio s1, s2 represents the portion of the current I HP1, I HP2 supplied by the high-pressure electrical source 122 HP1, 122 HP2 in question, relative to the sum of the currents I HP1, I HP2 supplied by all the high-pressure electrical sources 116 HP1, 116 HP2. Thus, the sum of the secondary ratios s1, s2 equals one. These secondary ratios s1, s2 are, for example, fixed.

[0050] Thus, each module 122 HP1, 122 HP2 is for example identical to the module 122 HP, except that the secondary ratio s1, s2 is taken into account to calculate the static gain K HP1, K HP2 to be provided.

[0051] In the illustrated example, the 306 blocks are designed to test an equality using a total high-pressure gain K HP = K HP1 + K HP2, in the same way as on the figure 4 Alternatively, other equivalent inequalities could be used, for example s1 · S / (1-S) · K BPmax < K HP1max = s1 · K HPmax for block 306 of module 122 HP1 and s2 · S / (1-S) · K BPmax < K HP1max = s2 · K HPmax for block 306 of module 122 HP2.

[0052] With reference to the figure 12 , another example of implementation of the 120 BP , 120 HP control modules , will now be described.

[0053] The 120 BP and 120 HP control modules are identical to those of the figure 2except that they each also include a 1202 BP, 1202 HP module for calculating a maximum current I BPmax, I HPmax and a 1204 BP, 1204 HP module for limiting the reference current I BP*, I HP* to this maximum current I BPmax, I HPmax. Thus, as long as each reference current I BP*, I HP* is less than its respective maximum current I BPmax, I HPmax, the electrical sources 116 BP, 116 HP are controlled according to the drowsiness gains K BP, K HP, so that the split S is respected. On the other hand, if one of the reference currents IBP*, IHP* becomes greater than its respective maximum current IBPmax, IHPmax, that reference current IBP*, IHP* is limited, and therefore also the current IBP, IHP supplied to the DC bus 112. The other reference current IBP*, IHP* can then continue to increase (as long as it does not reach its associated maximum current IBPmax, IHPmax).This allows more current to be delivered to the DC bus 112, at the expense of the split S which is then no longer respected.

[0054] With reference to the figure 13 and to the figure 14 , another example of the implementation of the 122 BP, 122 HP modules for calculating the K BP, K HP static gains of the figure 1 , which can in particular be used in combination with the 120 BP, 120 HP control modules of the figure 12 will now be described.

[0055] The 122 BP and 122 HP modules are identical to those of the figure 3 and of the figure 4 except that they include, instead of block 306, a block 1302 for calculating the static gain K BP , K HP from a constant K tmax deduced from the maximum powers P BPmax , P HPmax and the split S.

[0056] More precisely, the static gain K HP is given by: K HP = S · K tmax , while the static gain K HP is given by: K BP = (1 - S) · K tmax . (1-S) is thus the complement to one of the split S.

[0057] Preferably, the constant K tmax is equal to the sum of the maximum drastic gains K BPmax , K HPmax : K tmax = K BPmax + K HPmax .

[0058] The DC bus voltage U as a function of the currents IBP, IHP supplied to the DC bus 112 is illustrated on the figure 15 , in the case of a 50% split. As can be seen, the reference current I BP * has reached saturation.

[0059] In conclusion, it should be noted that the invention is not limited to the embodiments described above. Indeed, it will be apparent to those skilled in the art that various modifications can be made to the embodiments described above, in light of the information just provided.

[0060] In the detailed presentation of the invention given above, the terms used shall not be interpreted as limiting the invention to the embodiments set forth in this description, but shall be interpreted to include all equivalents covered by the claims which can be foreseen by a person skilled in the art by applying their general knowledge to the implementation of the teaching which has just been disclosed to them.

Claims

1. An apparatus (100; 900) for providing energy in an aircraft, comprising: - a DC bus (112) to which at least one electrical load (114) is intended to be connected; - several electrical sources (116BP, 116HP; 116BP, 116HP1, 116HP2) including: ∘ at least one electrical source referred to as low-pressure electrical source (116BP) designed to draw power from a low-pressure body (104) of a turbomachine (102) of the aircraft, in order to provide a current (IBP) to the DC bus (112), and ∘ at least one electrical source referred to as high-pressure electrical source (116HP ; 116HP1, 116HP2) designed to draw power from a high-pressure body (106) of the turbomachine (102) of the aircraft, in order to provide a current (IHP ; IHP1, IHP2) to the DC bus (112); characterised in that it further comprises: - a system (108, 122BP, 122HP; 108, 122BP, 122HP1, 122HP2) for calculating a droop gain (KBP, KHP; KBP, KHP1, KHP2) for each low-pressure electrical source (116BP) and each high-pressure electrical source (116HP ; 122HP1, 122HP2), on the basis of at least one operating characteristic of the turbomachine (102); and - for each low-pressure electrical source (116BP) and each high-pressure electrical source (116HP ; 122HP1, 122HP2), a module (120BP, 120HP; 120BP, 120HP1, 120HP2) for controlling the electrical source (116BP, 116HP; 116BP, 116HP1, 116HP2) under consideration, designed to implement a droop regulation on the basis of the droop gain (KBP, KHP; KBP, KHP1, KHP2) calculated for the electrical source (116BP, 116HP; 116BP, 116HP1, 116HP2) under consideration.

2. The apparatus (100) according to claim 1, wherein the at least one operating characteristic of the turbomachine (102) comprises at least one of: a fuel inlet flow rate and / or an air inlet flow rate into a combustion chamber of the turbomachine (102), a rotational speed of the low-pressure body (104), a rotational speed of the high-pressure body (106), an air inlet temperature and / or fuel inlet temperature and / or temperature of exhaust gases leaving the combustion chamber.

3. The apparatus (100; 900) according to claim 1 or 2, wherein the system (108, 122BP, 122HP; 108, 122BP, 122HP1, 122HP2) for calculating droop gains (KBP, KHP; KBP, KHP1, KHP2) comprises: - a controller (108) of the turbomachine (102) designed to define a ratio (S) between the power drawn from the high-pressure body (106) by the high-pressure electrical source or sources (116HP) and the power drawn from the low-pressure body (104) by the low-pressure electrical source or sources (116BP), on the basis of the operating characteristic or characteristics of the turbomachine (102); and - for each electrical source (116BP, 116HP; 116BP, 116HP1, 116HP2), a module (122BP, 122HP; 122BP, 122HP1, 122HP2) for calculating, from the ratio (S), the droop gain (KBP, KHP; KBP, KHP1, KHP2) of the electrical source (116BP, 116HP; 116BP, 116HP1, 116HP2) under consideration, so that the ratio (S) is complied with.

4. The apparatus (100; 900) according to claim 3, wherein the controller (108) is designed to provide data referred to as power data representative of a maximum low-pressure mechanical power (PBPmax_meca) that can be drawn from the low-pressure body (104) and a maximum high-pressure mechanical power (PHPmax_meca) that can be drawn from the high-pressure body (106), and wherein each calculation module (122BP, 122HP) is designed to calculate the associated droop gain (KBP, KHP) from the power data, so that the mechanical power drawn from the low-pressure body (104) remains less than or equal to the maximum low-pressure mechanical power (PBPmax_meca) and the mechanical power drawn from the high-pressure body (104) remains less than or equal to the maximum high-pressure mechanical power (PHPmax_meca).

5. The apparatus (100; 900) according to claim 4, wherein each calculation module (122BP, 122HP) is designed to calculate the associated droop gain (KBP, KHP) so as to maximise a sum of the currents (IBPmax, IHPmax) which can respectively be provided by the electrical sources (116BP, 116HP), when the DC bus (112) has a minimum bus voltage (UDCmin) predefined by the droop regulation.

6. The apparatus (900) according to any one of claims 1 to 5, comprising a plurality of high-pressure electrical sources (116HP1, 116HP2) and / or a plurality of low-pressure electrical sources, and wherein the calculation module (122HP1, 122HP2) of each high-pressure electrical source (116HP1, 116HP2), respectively low-pressure electrical source, is designed to calculate the associated droop gain (KHP1, KHP2) on the basis of a ratio (s1, s2) between, on the one hand, the current (IHP1, IHP2) provided by the high-pressure source (116HP1, 116HP2), respectively low-pressure source, under consideration and, on the other hand, a sum of the currents (IHP1, IHP2) respectively provided by all the high-pressure electrical sources (116HP1, 116HP2), respectively low-pressure electrical sources.

7. The apparatus (100; 900) according to claim 4, wherein each calculation module (122BP, 122HP) is designed to calculate the droop gain (KHP) of the high-pressure electrical source (116HP) as the product of the ratio (S) and a constant and the droop gain (KBP) of the low-pressure electrical source (116BP) as the product of the one's complement of the ratio (S) and the constant.

8. The apparatus (100; 900) according to any one of claims 1 to 7, wherein each control module (120BP, 120HP) is designed to: - calculate a reference current (IBP*, IHP*) from the associated droop gain (KBP, KHP); - calculate, from the power data, a maximum current (IBPmax, IHPmax) that can be provided by the associated electrical source (116BP, 116HP); and - limit the reference current (IBP*, IHP*) to the maximum current (IBPmax, IHPmax).

9. An aircraft comprising an apparatus according to any one of claims 1 to 8.

10. A method for providing energy in an aircraft, characterised in that it comprises: - calculating, from at least one measurement of at least one operating characteristic of a turbomachine (102), a droop gain (KBP, KHP) for: ∘ each electrical source referred to as low-pressure electrical source (116BP) designed to draw power from a low-pressure body (104) of the turbomachine (102) of the aircraft, in order to provide a current (IBP) to a DC bus (112) to which at least one electrical load (114) is intended to be connected, and ∘ each electrical source referred to as high-pressure electrical source (116HP) designed to draw power from a high-pressure body (106) of the turbomachine (102) of the aircraft, in order to provide a current (IHP) to the DC bus (112); and - for each low-pressure electrical source (116BP) and each high-pressure electrical source (116HP), a droop regulation is implemented on the basis of the droop gain (KBP, KHP) calculated for the electrical source (116BP, 116HP) under consideration.