Method and device for controlling the power of a three-phase AC network by parallel hybridization with a controlled inverter and a DC source

Abstract

The invention relates to a method (1) for supplying electrical energy to an electrical load, the method (1) comprising the steps: Measurement (10) of a voltage between a voltage source and an electrical load and of a current between the alternating voltage source and the electrical load, Measurement (20) of a voltage between a converter and the electrical load and of a current between the converter and the electrical load, Calculation (30) of an apparent power value S in the main network, Determination (40) of an active power value P and a reactive power value Q, Estimation (72) of a required power value, an active power value, and a reactive power value required for the electrical load, the required power being composed of the active power value and the reactive power value, If the required power value is greater than the apparent power S,injection (75) of a reactive complement or an active complement. Figure for the abbreviation: Fig. 1,

Description

Title of the invention: Method and device for controlling the power of a three-phase alternating network by parallel hybridization with a controlled inverter and a DC source.

[0001] The invention relates to a method for managing the operation of an aircraft electrical power supply system comprising at least one electrical energy storage assembly.

[0002] The electrical machines of an aircraft are today sized to take into account electrical overloads of the network as well as the abnormal case of loss of an alternator on one board. However, these sized powers are in fact rarely reached and are most often of short duration. This oversizing in power impacts the masses and volumes of the electrical machines and therefore more generally the energy consumption and emissions from the aircraft.

[0003] In addition, the primary avionics electrical network involves variable power levels depending on the flight cycle and requirements. Also, the emergence of new electrical functions particularly constrains this network. For example, electrical de-icing is a very high power load, which can reach several hundred kilowatts, but which is only used temporarily throughout the flight cycle.

[0004] Therefore, electrical machines must be sized to withstand these overloads but also to respond to abnormal cases of theft such as the loss of a generator for example. Nevertheless, these powers are rarely reached and consequently, the additional on-board mass resulting from oversizing can be seen as dead weight in most cases.

[0005] In addition, the variability of the primary network power impacts the performance of the alternator, the dimensioning of which is defined for nominal operation. The efficiency tends to decrease at lower power. However, the machines usually operate at these power levels.

[0006] One solution considered was to propose, in document WO 2018 / 051003 A1, a method for hybridizing a ram air turbine or RAT with a converter. The method described is a droop control strategy on the network voltage or frequency. However, this method cannot be applied to the main alternators of aircraft since the latter independently control the bus voltage to a constant value while the turbine imposes the network speed.

[0007] However, such a method has many drawbacks, such as, for example: the fact that the alternator control unit must switch to a phase current limitation mode in order to lower the network voltage setpoint. This assumes reaching a high overload regime before the auxiliary network acts.

[0008] In addition, static control requires degrading the network voltage, which has a slight impact on consumers since static loads will have to consume less power because the power is proportional to the square of the voltage.

[0009] And, knowledge of a single instantaneous quantity of the main source, such as for example the voltage, does not allow intelligent control of the power flows in the primary network.

[0010] The invention aims to overcome all or part of the problems mentioned above by proposing a solution for supplementing power to the electrical network from a source other than traditional electrical machines such as a battery-type source and a converter.

[0011] To this end, the invention relates to a method for supplying electrical energy to at least one electrical load in an aircraft electrical system, the aircraft electrical system comprising a main network and an auxiliary network, the main network comprising: - at least one source of alternating voltage by mechanical sampling on a drive system connected to a current generation control unit, the source of alternating voltage being connected to the at least one electrical load, the auxiliary network including: - at least one electrical energy storage unit, configured to provide an energy supplement to the at least one electrical load, - a converter arranged between the electrical energy storage assembly and the at least one electrical load, configured to convert a direct current into an alternating current, - a converter control module, configured to measure a voltage between the at least one alternating voltage source and the at least one electrical load and to measure an electrical voltage between the converter and the at least one electrical load, the feeding method comprising the following steps: - Measurement of a first voltage between the at least one alternating voltage source and the at least one electrical load and of a first current between the at least one alternating voltage source and the at least one electrical load, - Measurement of a second voltage between the converter and at least one electrical load and a second current between the converter and the at least one electrical load, - Calculation of an apparent power value S in the main network, - Determination of an active power value P and reactive power Q, - Estimation of a necessary power value SLoad, a necessary active power value Pu^j and a necessary reactive power value QI <xld à l’au moins une charge électrique, la valeur de puissance nécessaire SL()ild représentant la valeur de puissance à fournir à l’au moins une charge électrique, la valeur de puissance nécessaire SL(Xld étant composée de la valeur de puissance active nécessaire Pl^uI et de la valeur de puissance réactive nécessaire Q. ^Loaa* - If the detected necessary power value SLoad is greater than the apparent power S of the main network, injection of additional reactive power Qsupp and / or additional active power Psupp from the auxiliary network into the main network.

[0012] According to one aspect of the invention, the step of determining an active power and a reactive power comprises the following steps: - Observation of the characteristics of the main network and the auxiliary network, - Transformation of the active power value P and the power value reactive Q calculated according to a Park transformation, - Decoupling of the transformed active power value P and the transformed reactive power value Q, - Calculation of an active power value P in the main network, - Calculation of a reactive power value Q in the main network,

[0013] According to one aspect of the invention, the feeding method comprises the following steps: - If the necessary active power value Pestimated is lower than the apparent power S of the main network, injection of additional reactive power Qsupp from the auxiliary network into the main network, - Otherwise, injection of a reactive power supplement Qsupp from the auxiliary network into the main network and an active power supplement Psupp from the auxiliary network into the main network.

[0014] According to one aspect of the invention, the power supply method comprises a first strategy for linearizing the active power P and the reactive power Q, the first linearization strategy consisting of a definition of a reference active power value Pref and a reference reactive power value Qref, the reference active power value Pref being greater than the value of active power P and the reference reactive power value Qref being greater than the reactive power value Q.

[0015] According to one aspect of the invention, the power supply method comprises a second strategy for linearizing the active power P and the reactive power Q, the second linearization strategy consisting of a definition of a reference active power value Pref and a reference reactive power value Qref, the reference active power value Pref being greater than the active power value P and the reference reactive power value Qref being less than the reactive power value Q.

[0016] According to one aspect of the invention, the power supply method comprises a third strategy for linearizing the active power P and the reactive power Q, the third linearization strategy consisting of a definition of the reference active power value Pref and the reference reactive power value Qref, the reference active power value Pref being less than the active power value P and the reference reactive power value Qref being less than the reactive power value Q.

[0017] The invention also relates to a device for supplying electrical energy to at least one electrical load in an aircraft electrical system, the aircraft electrical system comprising a main network and an auxiliary network, the main network comprising: - at least one source of alternating voltage by mechanical sampling on a drive system connected to a current generation control unit, the at least one source of alternating voltage being connected to the at least one electrical load, the auxiliary network comprising: - at least one electrical energy storage assembly, configured to supply direct current to the at least one electrical load, - a converter arranged between the electrical energy storage assembly and the at least one electrical load, configured to convert a direct voltage into an alternating voltage, - a converter control module, configured to measure a voltage and a current between the at least one alternating voltage source and the at least one electrical load and to measure an electrical voltage and a current between the converter and the at least one electrical load, the control module being configured to inject a reactive power supplement Qsupp and / or an active power supplement Psupp from the auxiliary network into the main network if a power value necessary for the at least one load electrical power is greater than an apparent power value S of the main network.

[0018] According to one aspect of the invention, the at least one electrical energy storage assembly is a battery.

[0019] According to one aspect of the invention, the main network and the auxiliary network are three-phase networks.

[0020] According to one aspect of the invention, the at least one alternating voltage source is an alternator.

[0021] According to one aspect of the invention, the power supply device comprises a filter arranged between the converter and the at least one electrical load.

[0022] According to one aspect of the invention, the power supply device comprises a hybridization contactor configured to couple and decouple the main network and the auxiliary network.

[0023] The invention will be better understood and other advantages will appear on reading the detailed description of an embodiment given by way of example, a description illustrated by the attached drawing in which:

[0024] [Fig-1] [Fig.l] represents a schematic view of a method of feeding into electrical energy of at least one electrical load in an aircraft electrical system according to the invention;

[0025] [Fig.2] [Fig.2] represents a schematic view of the feeding process in electrical energy of [Fig.l];

[0026] [Fig.3] [Fig.3] represents a schematic view of a device for supplying electrical energy of at least one electrical load in an aircraft electrical system according to the invention;

[0027] [Fig.4A] [Fig.4A] represents a schematic view of a first phase of a digital implementation of the feeding method of [Fig.l];

[0028] [Fig.4B] [Fig.4B] represents a schematic view of a second phase of a digital implementation of the feeding method of [Fig.l];

[0029] [Fig.5] [Fig.5] represents a graph of the observed energy compensation by means of the feeding method of [Fig.l];

[0030] [Fig.6] [Fig.6] represents a graph of the decoupling of the compensation energy between active and reactive power.

[0031] For the sake of clarity, the same elements will bear the same references in the different figures.

[0032] [Fig. 1] thus represents a schematic view of a method 1 for supplying electrical energy to at least one electrical load 200 in an aircraft electrical system 300. An electrical load is an electrical component of the aircraft that consumes energy. The aircraft electrical system 300, as represented in [Fig. 3], comprises a main network 110 and an auxiliary network 120.

[0033] The main network 110 comprises at least one alternating voltage source 111 by mechanical sampling on a drive system 112 connected to a current generation control unit 113. The alternating voltage source 111 is thus connected to the at least one electrical load 200.

[0034] Preferably, the at least one alternating voltage source is a voltage-regulated alternating current source electrical machine 111.

[0035] The auxiliary network 120 comprises at least one electrical energy storage assembly 121 configured to provide an energy supplement to the electrical load at the at least one electrical load and capable of supplying direct current to the at least one electrical load 200. In other words, the electrical energy storage assembly 121 provides a direct electric current and is connected to the at least one electrical load 200.

[0036] The auxiliary network 120 also comprises a converter 122 arranged between the electrical energy storage assembly 121 and the at least one electrical load 200, configured to convert a direct current into an alternating current. The electrical energy storage assembly 121 thus supplies a direct current to the converter 122 which converts it.

[0037] The auxiliary network 120 also comprises a control module 123 of the converter 122, configured to measure a voltage between the at least one alternating voltage source 111 and the at least one electrical load 200 and to measure an electrical voltage between the converter 122 and the at least one electrical load 200. The control module 123 of the converter 122 is also capable of measuring the electrical current between the at least one alternating voltage source 111 and the at least one electrical load 200 and of measuring an electrical current between the converter 122 and the at least one electrical load 200.

[0038] The main network 110 and the auxiliary network 120 are therefore two separate electrical networks, both connected to at least one electrical load 200.

[0039] Optionally, the auxiliary network 120 may also comprise a filter 124 disposed between the converter 122 and the at least one electrical load 200 configured to eliminate the voltage harmonics linked to the switching of the converter 122 and to generate a sinusoidal three-phase voltage within the auxiliary network 120.

[0040] Optionally, the auxiliary network 120 may comprise a hybridization contactor 126 between the filter 124 and the main network 110 making it possible to isolate or couple the secondary network 120 to the main network 110, and thus to power the at least one electrical load 200 using the auxiliary network 120.

[0041] Preferably, the measurement of voltage and current of the main network 110 is carried out by the control module 123 at the alternating voltage source 111 and, according to an ideal configuration, upstream of the parallelization of the main network 110 and the auxiliary network 120. And, the voltage measurement of the auxiliary network 120 by the control module 123 is carried out between the converter 122 and the parallelization of the main network 110 and the auxiliary network 120 and, ideally between the filter 124 and the hybridization contactor 126. Alternatively, the current measurement of the auxiliary network 120 can be carried out between the converter 122 and the filter 124.

[0042] The power supply method 1 comprises a first step 10 of measuring a first voltage between the at least one alternating voltage source 111 and the at least one electrical load 200. It is also envisaged, during the measuring step 10, to measure, during this measuring step 10, a first current between the at least one alternating voltage source 111 and the at least one electrical load 200.

[0043] Following step 10, the power supply method 1 comprises a step 20 of measuring a second voltage between the converter 122 and the at least one electrical load 200. And, similarly to step 10, it is also envisaged to measure, during this measurement step 20, a second current between the converter 122 and the at least one electrical load 200. Preferably, the measurement of the second voltage at the output of the converter 122 is observed only if the hybridization contactor 126 is in a closed position, that is to say allowing the connection between the main network 110 and the auxiliary network 120.

[0044] Indeed, it is necessary to know the electrical power that the at least one alternating voltage source 111 can provide in real time. Thus, the electrical power is determined from the knowledge of the electrical voltage, namely the first electrical voltage, and the electrical current, namely the first electrical current, between the at least one alternating voltage source 111 and the at least one electrical load 200.

[0045] Thus, following step 10 and preferably, following measurement steps 10 and 20, the power supply method 1 comprises a step 30 of calculating an apparent power value in the main network. The notion of apparent power is a maximum power value available for operating an electrical network. It is the trigonometric sum of the active power and the reactive power.

[0046] Preferably, the apparent power can be defined according to the following formula:

[0047] S = y{PT~+Qr (1)

[0048] Where P represents the value of the active power in the main network 110 while Q represents the value of the reactive power in the main network 110.

[0049] More precisely, apparent power is the trigonometric sum of two components, namely active power and reactive power. Active power allows work or heat to be generated, while reactive power is an unproductive power but necessary for inductive and capacitive dipoles to generate a magnetic or electrostatic field respectively. In other words, active power allows an action or movement to be caused. Active power can then be interpreted as “useful” power. Active power thus uses part of the energy made available by apparent power. Conversely, reactive power is a power that does not allow an action to be developed.

[0050] Alternatively, this calculation can be done using the following formula:

[0051] 5 = Ueff*Ieff for a single-phase network and 5 = (2) For a network three-phase as shown in Figure 3,

[0052] Where S represents the apparent power value available in the main network 110, U(,ff represents the effective voltage value measurable in the main network, and h / f represents the effective current value measurable in the main network. In a three-phase reference frame, Veff then represents the neutral phase voltage value and ieff the effective phase current value.

[0053] Nevertheless, any other means making it possible to calculate the value of the apparent power available in the main network 110 can be envisaged.

[0054] Furthermore, it may also be envisaged to directly measure this power value in addition to the voltage and current in the first network 110.

[0055] After having calculated the apparent power value of the main network 110, it is possible to determine, during a determination step 40, the active power value P and the reactive power value Q.

[0056] To do this, preferably, the determination step 40 comprises a step 45 of observing the physical characteristics of the main network 110 and the auxiliary network 120. Indeed, in order to subsequently carry out a change of reference, it is necessary to observe the position of the main network 110 relative to the auxiliary network 120. More precisely, it is necessary that the current and the voltage measurable at the level of the main network 110 and the auxiliary network 120 have the same frequency and the same phase.

[0057] To do this, the power supply method 1 applies a phase-locked loop or PLL function which makes it possible to guarantee that the current and voltage at the main network 110 connected to the auxiliary network 120 have the same frequency and the same phase.

[0058] This is followed by a transformation step 50 of the active power value P and the reactive power value Q according to a Park transformation. This then involves making a change of reference in the Park vector reference frame. Therefore, in the Park vector reference frame, the active power value P and the reactive power value Q are written according to the following formulas:

[0059] P = Hvd*ld+Vq*I,)

[0060] Q=l(Vqnd-Vd*I^

[0061] Where ddq represent the two axes of the Park vector frame. Vd thus represents the value of the first voltage along the d axis while represents the value of the first current along the d axis. And, Vq thus represents the value of the first voltage along the q axis while Iq represents the value of the first current along the q axis.

[0062] This is followed by a decoupling step 60 of the transformed active power value and the transformed reactive power value. To do this, the power supply method 1 applies a phase-locked loop or PLL function to the transformed active power value and the transformed reactive power value. The PLL function makes it possible to estimate the position of the main network 110 which, by Park transform, imposes the following condition:

[0063] Vq = 0

[0064] In other words, the PLL function makes it possible to determine an angle imposing the voltage value on the axis of the vector reference q such that Vq — 0.

[0065] For information purposes, the PLL function used during step 45 may preferably be identical to the PLL function of the decoupling step 60.

[0066] Following step 50, the power supply method 1 comprises a step 70 of calculating an active power value in the main network 110 and a step 70' of calculating a reactive power value in the main network 110, the active power and the reactive power being the components of the apparent power calculated during step 30.

[0067] Indeed, the transformed active power value and the transformed reactive power value being decoupled and only carried by the currents Id and Iq, the value of the active power P can be calculated during step 70 according to the following formula:

[0068] P=ÿyd*Id)

[0069] And the value of the reactive power Q can be calculated during step 70' according to the following formula:

[0070] Q=

[0071] It should be noted that steps 70 and 70' can be performed simultaneously.

[0072] Furthermore, the determination, during step 40, of the active power P and the reactive power Q can be carried out differently than stated above.

[0073] Indeed, in a three-phase network configuration, the determination step 40 can firstly comprise the calculation step 70 of the active power value according to the following formula:

[0074] P = V / i + V2 / 2 +

[0075] Where, ^represents a measurable voltage value between a first phase and the neutral and ^represents a current value of the first phase, ^represents a measurable voltage value between a second phase and the neutral and ^represents a current value of the second phase and V3represents a measurable voltage value between a third phase and the neutral and / 3 represents a current value of the third phase.

[0076] In other words, in a multi-phase configuration, the value of the active power can be defined according to the following generic formula: [00771 p=L .vl ^j^abc JJ

[0078] Where ^ represents the set of voltage values ​​of each phase of the multiphase main network 110 and ^ / represents the set of current values ​​of each phase of the main network 110.

[0079] Thus, knowing the value of the apparent power S and the value of active power P, it is possible to calculate the value of reactive power Q at step 70' according to the following formula:

[0080] q _ ^2 p2

[0081] Then follows the step 45 of observing the physical characteristics of the main network 110 and the auxiliary network 120 and more precisely the frequency and the phase of the main network 110 and the auxiliary network 120. Also follows the step 50 of transforming the active power value P and the reactive power value Q according to the Park transformation and the step 60 of decoupling the transformed active power value and the transformed reactive power value as stated previously.

[0082] It should be noted that the determination step 40 is also applicable in a single-phase network configuration in a similar manner. Indeed, during the decoupling step 60 of the transformed active power value and the transformed reactive power value for which the PLL function is applied, a single-phase type PLL function is applied, such as for example a SOGLOSG PLL function.

[0083] Alternatively, it may be envisaged, during step 70, to calculate the active power according to the following formula:

[0084] P- L7* / *cos(ç>)

[0085] Where U represents the first voltage value measured in the main network 110, 1 represents the first current value measured in the main network 110 and V represents a phase shift.

[0086] And, similarly, it may be envisaged, during step 70', to calculate the reactive power according to the following formula:

[0087] Q^U*I*sïn( <p)

[0088] Where U represents the first voltage value measured in the main network 110.1 represents the first current value measured in the main network 110 and represents a phase shift.

[0089] Other formulas or methods may be envisaged to enable the calculation of the value of the active power and the value of the reactive power in the main network 110.

[0090] Thus, the determination of the active power P and the reactive power Q in the main network 110 can be envisaged in different ways, by first calculating a value of active power and reactive power then by carrying out a Park transformation in a determined reference frame or inversely by first carrying out the transformation, by imposing a current parameter and by calculating the values ​​of active power and reactive power.

[0091] In a preferred embodiment of the determination step 40, the steps follow one another in the following manner: observation step 45, transformation step 50, decoupling step 60, calculation step 70 and calculation step 70'. However, in another embodiment, it may be envisaged that the steps follow one another in the following manner: calculation step 70, calculation step 70', observation step 45, transformation step 50 and decoupling step 60. This embodiment requires knowing the effective values ​​of the voltages and currents of the main network 110 and therefore greater computing power.

[0092] Following the determination step 40, the power supply method 1 comprises a step 72 of estimating a necessary power value SLoad, a necessary active power value Plocm and a necessary reactive power value QLoad for at least one electrical load 200. This necessary power value ^Load thus represents the power value to be supplied to the at least one electrical load 200 in order to enable its operation. This estimation of the necessary power SLoad may be known upstream due to the technical characteristics of the at least one electrical load 200 connected to the main network 110, and more precisely, the dimensional characteristics of the main network 110, or via the control module 123. According to this configuration, the control module 123 is also then connected to the at least one electrical load 200.More precisely, the necessary power value SLoad can be assimilated to a sum of a necessary active power value PLoad given that this power allows the operation of the at least one electrical load 200 and to a necessary reactive power value Q, ^Loaa .

[0093] In other words, the necessary active power P^ad and the necessary reactive power Qj consumed by the at least one load 200 are identifiable by the superposition theorem so that the necessary active power PLoad is equal to the set of active power values ​​P in the electrical network and that the necessary reactive power is equal to the set of reactive power values ​​Q in the electrical network. Therefore, when only the main network 110 is connected to the at least one electrical load 200, in nominal operation of the aircraft electrical system 300, the necessary active power P Load is defined as:

[0094] Pload = P

[0095] and the necessary reactive power is defined as:

[0097] Thus, as previously stated, the contribution of the powers in the main network 110 is written as follows:

[0098] C _ / p 2 , Z) 2 Load and load ^ipad

[0099] Preferably, the estimation of the necessary active power Ptoad, of the necessary reactive power Qr, and therefore of the necessary power SLoad at the LtUUii less an electrical load 200 is derived from the measurements of active power P and reactive power Q on the main network 110.

[0100] Therefore, three power supply configurations can be envisaged depending on the powers available in the main network 110, i.e. the active power value P and the reactive power value Q, and the necessary power SLoad of the at least one electrical load 200.

[0101] A first configuration can be envisaged when the power to be supplied to the at least one electrical load 200, i.e. the necessary power SLoad, is less than or equal to the design limit power of the AC voltage source 111. Therefore, if the necessary power S^d does not exceed the apparent limit power value Siim specific to the main network 110, it is not necessary for the power supply method 1 to provide any compensation from the auxiliary network 120. The apparent limit power value SIim of the main network 110 thus represents the maximum power value that the main network 110 can supply to the at least one electrical load 200. This design limit power value Sfjm then depends on the design characteristics of the main network 110.

[0102] Thus, if Sj^d < SUm then the power supply method 1 does not draw power from the auxiliary network 120 and no compensation is carried out.

[0103] Stated differently, according to the first configuration, the necessary power SLmid of the at least one electrical load 200 is less than an apparent power limit for sizing the main network, that is to say that the following equation is respected: [°104l Su”, = 7¾.2 + Qti„ 2 * = ^P^+Q^

[0105] Where, Pnm represents the limit active power value for sizing the main network 110 and Qu represents the limit reactive power value for sizing the main network 110.

[0106] Then it is not necessary to add any power from the auxiliary network 120.

[0107] Conversely, if the detected necessary power value SLt>ad is greater than the apparent limit power S!im of the main network 110, the power supply method 1 then comprises a step 75 of injecting additional reactive power Qmpp and / or active power / A^p from the auxiliary network 120 into the main network 110.

[0108] Therefore, if SLoad > SUm then the power to be supplied to the at least one electrical load 200 exceeds the sizing limit power of the alternating voltage source 111, and it is therefore necessary to add to the apparent power S of the main network 110 a supplement of reactive power Qsupp and / or active power Psupp coming from the auxiliary network 120. Therefore, the apparent power S of the main network, during the injection step 75 can be defined according to one of the following formulas: 101091

[0110] The definition of the apparent power of the main network 110 during the injection step 75 can be done in a predetermined manner.

[0111] Nevertheless, it can be envisaged that the definition of the apparent power during the injection step 75 is determined by the supply method 1.

[0112] Indeed, as stated previously during step 72, it is possible to estimate the necessary active power value P Load for the at least one electrical load 200 and the necessary reactive power value QL d for the at least one electrical load 200.

[0113] However, if the necessary active power value Ppoad estimated during step 72 does not exceed a combined value between the active power value P of the main network 110 at the time and the dimensioning limit reactive power value Qlim of the main network 110, it is then possible to limit the apparent power of the main network 110 by injecting only a reactive power supplement QsuPp from the auxiliary network 120. This injection of reactive power supplement Qiupp from the auxiliary network 120 has the advantage of not having an impact on the electrical energy storage assembly 121.

[0114] In other words, if the necessary active power value Ppoad is less than or equal to the modulus of the sum of the active power P and the power value reactive sizing limit QPm of the main network 110, the supply method 1 comprises a step 750 of injecting a reactive power supplement Qsupp from the auxiliary network 120 into the main network 110. Thus, if P Load $Load > ^Zrâthen the power supply method 1 allows an injection, according to step 750 of a reactive power supplement Qsupp from the auxiliary network 120 into the main network 110 and the apparent power in the main network 110, during the injection step 750, can be defined according to the following formula:

[0115] S = Jpï~^^ = 2 + 2 < 2 y ^suppj y ^rej

[0116] Where Qref represents the sum of the reactive power value Q initially present in the main network 110 and the value of the reactive power supplement Qsupfr This sum can also be interpreted as a reference reactive power value to meet the two conditions mentioned above, namely PLoad and $Load > S.

[0117] Alternatively, the following conditions may be considered as a condition for the injection 750 of additional reactive power Qsupp from the auxiliary network 120 into the main network 110: PLad and Sr < > Sr Load limit

[0118] Therefore, the condition on the necessary active power value PLoad for the at least one electrical load 200 is simplified since the apparent power value S of the main network 110 is known.

[0119] This second configuration translates as the case in which the apparent power of the at least one electrical load 200 is greater than a limit apparent power but the active power of the loads is less than this same apparent power. Thus before compensation of the auxiliary network 120, it is possible to observe an excess of the power in the main network 110 compared to the limit apparent power of conceivable design. The aim is then to regulate the power of the network to reduce it to this limit power by injecting only reactive power from the auxiliary network 120, thus making it possible to limit the reactive power of the aircraft electrical system 300.

[0120] Otherwise, a third operating configuration can be envisaged. Indeed, if the power to be supplied to the at least one electrical load 200, i.e. the necessary power SLoad^ exceeds the apparent power S available in the main network 110, and if the necessary active power PLoad to the at least one load 200 also exceeds the apparent power S available in the main network 110 then the power supply method 1 allows an injection of additional power reactive Qslipp and an active power supplement Psupp-

[0121] In other words, if the necessary active power value Pu>ad is greater than the apparent power S of the main network 110, the power supply method 1 comprises a step 752 of injecting a reactive power supplement Q^pp from the auxiliary network 120 into the main network 110 and a reactive power supplement Pwp / xiu from the auxiliary network 120 into the main network 110.

[0122] So, if jp 2 + (7 2 and that ± Loua y* lim ' nfn ~ SIfXjd > Then the power supply method 1 allows an injection, according to step 752, of a reactive power supplement Qsupp from the auxiliary network 120 into the main network 110 and of an active power supplement P«v / xiu auxiliary network 120 into the main network 110 the apparent power in the main network 110. Thus, during the injection step 752, the apparent power can be defined according to the following formula: 101231 s = +

[0124] Where Qref represents the sum of the reactive power value Q initially present in the main network 110 and the value of the reactive power supplement Qsupp and P ref represents the sum of the active power value P initially present in the main network 110 and the value of the active power supplement Psupp.

[0125] The sum Qref can also be interpreted as a reference reactive power value while the sum Pref can also be interpreted as a reference active power value to meet the two conditions mentioned above, namely and SLoad > S.

[0126] Alternatively, the following conditions may be considered as a condition for the injection 752 of a reactive power supplement Qsupp from the auxiliary network 120 and of an active power supplement Psupp into the main network 110: PLoad > lim and S > s ■Load ' -lim

[0127] Therefore, the condition on the necessary active power value PLoad for the at least one electrical load 200 is simplified since the limit apparent power value for dimensioning $nm of the main network 110 is known.

[0128] This third configuration translates as the case in which the necessary apparent power of the at least one electrical load 200 is greater than a limit apparent power for sizing the main network 110 and the necessary active power of the at least one electrical load 200 is also greater than this limit. same apparent power design limit. Thus, before compensation by the auxiliary network 120, it may be observed that the power of the main network 110 exceeds the power limit accepted in the main network 110, characterized by the Slim power limit value. Similarly, it is possible to observe that the active power of the main network 110 exceeds the power limit accepted in the main network 110, characterized by the Slim power limit value.

[0129] In the third configuration, the additional reactive power Qsupp that is added fully compensates for the reactive power Q that the main network 110 provides so that Q + Qsupp = 0. Indeed, this power is signed. As an indicative example, it is then possible to carry out a power factor correction (PFC).

[0130] Thus, the power supply method has the advantage of allowing optimized management from one configuration to another configuration compared to the three configurations mentioned above as a function of the apparent power S available in the main network 110, the apparent limit power Slim linked to the sizing of the main network 110 and the necessary power SL(Xld for the at least one electrical load 200.

[0131] Indeed, when the necessary power of the at least one electrical load 200 exceeds the apparent power S of the main network 110, the power supply method 1 makes it possible to target the second configuration or the third configuration with respect to the necessary active power value PLoad-

[0132] Similarly, during active load shedding, i.e. when the at least one electrical load 200 no longer requires a certain quantity of active power Phoad necessary for its operation, in the third configuration, the power supply method 1 is advantageously capable of determining whether the main network 110 must be supplied according to the first configuration or the second configuration.

[0133] [Fig. 3] thus represents a device 100 for supplying electrical energy to at least one electrical load 200 in an aircraft electrical system according to the supply method 1. The supply device 100 is composed in particular of the main network 110 and the auxiliary network 120. And, the main network 110 comprises the at least one source of alternating voltage 111 by mechanical tapping on the drive system 112 connected to the current generation control unit 113. And, as previously stated, the at least one source of alternating voltage 111 is connected to the at least one electrical load 200.

[0134] And, as stated previously, the auxiliary network 120 comprises: - The at least one electrical energy storage assembly 121 configured to supplying direct current to the at least one electrical load 200, - the converter 122, arranged between the electrical energy storage assembly 121 and the at least one electrical load 200 and configured to convert the direct current delivered by the at least one electrical energy storage assembly 121 into an alternating current, - and the converter control module 123 configured to measure the voltage and current between the at least one alternating voltage source 111 and the at least one electrical load 200 and to measure the electrical voltage and current between the converter 122 and the at least one electrical load 200.

[0135] Optionally, the auxiliary network 120 may also comprise a filter 124 disposed between the converter 122 and the at least one electrical load 200 configured to eliminate the voltage harmonics linked to the switching of the converter 122 and to generate a sinusoidal three-phase voltage within the auxiliary network 120.

[0136] Optionally, the auxiliary network 120 may comprise a hybridization contactor 126 between the filter 124 and the main network 110 making it possible to isolate or couple the secondary network 120 to the main network 110, and thus to power the at least one electrical load 200 using the auxiliary network 120.

[0137] Furthermore, the at least one electrical energy storage assembly 121 is a battery. Alternatively, the at least one electrical storage assembly is a DC voltage source. For example, a DC voltage power supply, another source of alternating or direct current coupled to power electronics regulating the output DC voltage may be envisaged.

[0138] Furthermore, preferably, the main network 110 and the auxiliary network 120 are three-phase networks, as shown in [Fig. 3]. However, the main network 110 and the auxiliary network 120 may also be single-phase alternating networks or even multi-phase networks. Therefore, the phase-locked loop function or PLL to the transformed active power value and to the reactive power value is adapted according to the number of phases of the main network 110 and the auxiliary network 120. As an indicative example, a PLL function of the SOGLOSG type may be envisaged in a situation of a single-phase alternating main network 110 and auxiliary network 120 in order to allow a transformation into a two-phase vector reference frame.

[0139] And, according to a preferred variant, the at least one alternating voltage source 111 is an alternator or a three-stage machine commonly used for the electrical generation of the aircraft network, the output voltage of which is regulated to a constant value independently of the speed of the rotating shaft.

[0140] Alternatively, any regulated voltage source such as a three-phase voltage inverter, a Park group can be considered.

[0141] Furthermore, the management of the switches between one configuration and another configuration may be considered difficult, in particular due to the fact that, when the command arrives in permanent mode, the apparent power required by the at least one electrical load 200 is approximately equivalent to the apparent power limit Slim of the main network 110, that is to say that it oscillates numerically around the apparent power S. Therefore, switches, reflecting these oscillations, between the different configurations may be observed very closely. Furthermore, multiple load sheddings of the at least one electrical load 200 may induce multiple configuration switches among the three power supply configurations of the power supply method 1.

[0142] Figures 4A and 4B schematically represent the linearization strategies of the three power supply configurations of the power supply method 1. These linearization strategies advantageously make it possible to calculate power references making it possible to compensate for the lack of active power or reactive power in the main network 110. The different linearization strategies can thus be defined according to two levels: a first level during which reference powers are determined, as represented in [Fig.4A], and a second level during which a regulation of the current in the Park reference frame is determined, as represented in [Fig.4B].

[0143] As observed previously, these linearization strategies allow a decoupling of control of the active power value P and the reactive power value Q of the main network 110 on the two axes of the vector frame after Park transform during step 50. As stated previously, two axes are then identified according to the Park vector frame, namely the d axis and the q axis.

[0144] The control of the active power value P of the main network 110 provides information on the current directed on the d axis of the Park vector reference that the converter 122 must supply.

[0145] Each linearization strategy of the different configurations of the power supply method 1, namely the first configuration, the second configuration and the third configuration, thus makes it possible to define the reference active power value ref and the reference reactive power value Qref from so as to respect the conditions stated previously, as represented in [Fig.4A].

[0146] In the third configuration, the difference 1001 between the apparent power value Slim limit of the main network 110 and the necessary active power value PLoad is negative and saturation makes it possible to impose a positive active current reference, by changing the sign of the active current for example. In other words, in the third configuration, the reactive power value Q of the main network is regulated to 0 and the value of the active power P is regulated to the value of the apparent power Slim limit of the main network so as to force the auxiliary network 120 to compensate all the reactive power by means of the reactive power supplement and to provide the active power supplement Psupp necessary to the main network 110.

[0147] Saturation makes it possible to generate an active current reference in the inverter only when the difference 1001 between the apparent power value Slim limit of the main network 110 and the necessary active power value Pi^ad is negative, that is to say when the power supply method 1 is in the third configuration. Otherwise, when the power supply method 1 is in the first configuration or in the second configuration, the reference is set to 0.

[0148] The control of the reactive power value Q of the main network 110 provides information on the current directed on the q axis in the Park frame that the converter 122 must supply according to the configuration of the power supply method 1.

[0149] The reference reactive power value Qref corresponds, for its part, to the reference reactive power to allow the main network 110 to increase its available power to a limit apparent power value Slim knowing the active power, in the second configuration.

[0150] However, in the first power supply configuration of the power supply method 1, this power exceeds the reactive power value Q in the main network 110 and the saturation prevents any action of the converter 122.

[0151] And, according to the third power supply configuration of the power supply method 1, it is necessary to linearize the calculation of the reference reactive power value during the transient time of the regulation of the active power value. In established steady state, the reference reactive power is then zero.

[0152] Therefore, according to the first feeding configuration of the feeding method 1, the following conditions are defined: 101531 s^s^+e* = > p 2

[0154] Indeed, the apparent power in the main network 110, image of the apparent power SLoad, being lower than the acceptable power limit for the main network 110, it is possible to define, according to a first linearization strategy, the active power P and the reactive power Q of the main network 110 as:

[0155] Pref^P and Qref>Q = > Pref-P and Qref-Q >Q

[0156] The two current references according to the Park frame can then be defined as follows, according to the first linearization strategy:

[0157] Ly = 0 and Iq, = 0

[0158] Where Idref and Iqref represent the reference currents along the d and q axes of the Park frame.

[0159] This first strategy of the first configuration then results in an absence of injection of compensation from the auxiliary network 120 and therefore a decoupling of the auxiliary network 120 and the main network 110 by the action of the hybridization contactor 126. The first linearization strategy therefore makes it possible to impose operation according to the first compensation configuration, by imposing Pref P and Qref > Q .

[0160] Regarding the second power supply configuration, the following conditions are defined: [01611 .WS = ^p^+Q^ and P=>^~pf <q etslin>P

[0162] It is also possible to define the reference active power value Pref and the reference reactive power value Qrej according to a second linearization strategy, by means of the following inequality:

[0163] Ptef^P etQ^Q = > Pref-P and Qref-Q<^

[0164] The two current references according to the Park frame can then be defined as follows, according to the second linearization strategy: [0!65] jq tI +£Ô

[0166] Where K and K represent coefficients of a known proportional-integral corrector. Alternatively, other correctors can also be considered.

[0167] In other words, the second linearization strategy according to the second power supply configuration makes it possible to impose a zero value on a current in the Park frame.

[0168] The objective is then to regulate the power of the aircraft electrical system 300 to lower it by injecting only reactive power, thus making it possible to limit the reactive power of the aircraft electrical system 300. The second linearization strategy thus allows operation according to the second compensation configuration by imposing Pref P and Qref Q

[0169] And, in the third configuration of the feeding method 1, the following conditions are defined ■If™< S = and < PP0R

[0170] However, the necessary apparent power of the at least one electrical load 200 is greater than a limit apparent power SUm and the necessary active power of the at least one electrical load 200 is also greater than this same limit apparent power Sum. Thus, before compensation by the auxiliary network 120, it is possible to observe an excess of the power in the main network 110 compared to its design power limit. And, similarly, it is possible to observe an excess of the active power in the main network 110 compared to its design power limit.

[0171] From then on, it is possible to define the active power P and the reactive power Q of the main network 110 as: 101721 sign(Q) P 2| < Q and SKm < P

[0173] And, it is possible to define the reference active power value Pref and the reference reactive power value Qref according to a third linearization strategy, by means of the following inequality:

[0174] Pref <p et qref < q

[0175] That is to say Pref-P <0 and Qret-Q<0

[0176] The two current references according to the Park reference can then be defined, in steady state, as follows: 101771

[0178] The negative gain makes it possible to obtain a positive reference d-axis current and therefore a positive active power:

[0179] P = ^1,,

[0180] The third linearization strategy thus allows operation according to the third compensation configuration by imposing Pref P and Qref Q

[0181] Each of the linearization strategies, namely the first linearization strategy, the second linearization strategy and the third linearization strategy, for determining the active power and reactive power references, can be implemented according to a functional diagram represented in [Fig.4A].

[0182] As shown in [Fig.4B], following the determination of the energy compensation configuration, and therefore of the linearization strategy and the active power and reactive power references, two nested loops in cascade make it possible to implement to control the converter 122: - A first external regulation loop 1010 which allows the control of the powers of the main network 110, that is to say the control of the active powers P and reactive powers Q of the network in order to limit the apparent power S. The external regulation loop 1010 provides current references at the output of the auxiliary network 120. In other words, the first external regulation loop 1010 imposes a current reference on the d axis and the q axis according to the Park reference at the level of the auxiliary network 120. For information purposes, the first internal regulation loop 1010 adds compensation terms linked to the decoupling of the active power and reactive power values ​​and to the output voltage. - A second internal regulation loop 1020 which allows the control of the currents at the output of converter 122. More precisely, the second internal regulation loop 1020 comprises a first current regulator 1021 on the first axis of the Park frame, the d axis for example and a second current regulator 1022 on the second axis of the Park frame, the q axis. The first current regulator 1021 imposes a first control reference 1023 on the converter 122 along the first axis of the Park frame, the d frame, and the second current regulator 1022 imposes a second control reference 1024 on the converter 122 along the second axis of the Park frame, the q frame, so as to allow the converter 122, depending on the detected configuration, either the reactive power, or the reactive power and the active power, or no compensation to the at least one electrical load 200.

[0183] Figure 5 represents a graph of the energy compensation observed by means of the power supply method 1 during a given period. According to the example represented by this graph, the apparent power limit Sum of the main network 110 is 40 kVA. Thus, as long as the power demand, or in other words, the necessary power value SLoad remains lower than the apparent power limit SUm of the main network 110, the power supply method 1 remains in the first configuration.

[0184] When the power demand, i.e. the value of the necessary power SLoad for the at least one payload 200 exceeds the apparent power limit S set for the at least one AC voltage source 111 but the necessary active power value P^ad remains less than or equal to the apparent power limit S set for the at least one AC voltage source 111, as illustrated in the intervals [0.5; 1.6] and [1.9; 2.5] in the graph of [Fig. 5], the power supply method 1 then switches to an energy compensation configuration, i.e. the second configuration or the third energy compensation configuration in order to provide compensation in reactive power and possibly in active power from the auxiliary network 120.Therefore, an additional supply of reactive power can be observed from the auxiliary network 120, making it possible to extend, transiently, the apparent power value S beyond its basic value. When switching to the second configuration or to the third configuration, the converter 122 provides power compensation by regulation as indicated in [Fig.4B]. Since this compensation is not instantaneous, the main network 110 observes a power transient whose value depends on the load impact, here 45kVA or 50kVA. This compensation is also carried out promptly so as to avoid any . unwanted heating of the aircraft electrical system 300.

[0185] Conversely, if the necessary power value SL(Kid is lower than the apparent power S!im limit of the main network 110, then the auxiliary network 120 does not provide any power and the power of the main network 110 provides all the power to the at least one electrical load 200, highlighting the first energy compensation configuration. This is the case on the intervals [0; 0.5], [1.6; 1.9] and [2.4; 2.7] on the graph of [Fig.5].

[0186] For information purposes, the power supply method 1 is in the second energy compensation configuration at the intervals [0.5; 0.8], [1.3; 1.6] and in the third energy compensation configuration at the intervals [0.8; 1.3] and [1.9; 2.4],

[0187] The power supply method 1 also allows a reverse switchover, i.e. a switchover from the third power supply configuration to the second power supply configuration as shown at 1.3 seconds on the graph of [Fig.5], and a switchover from the second configuration to the first configuration when no compensation is necessary, as shown at 1.6 seconds on the graph of [Fig.5]. In addition, the power supply method 1 also allows a switchover from the first configuration to the third configuration and vice versa during a large variation in the active power demand at the at least one electrical load 200, as shown at the interval [1.9; 2.4] on the graph of [Fig.5].

[0188] Figure 6 illustrates the different compensation configurations in which the aircraft electrical system 300 can be found depending on the energy requirement of the at least one electrical load 200, and more precisely the application of the second configuration and the third energy compensation configuration. Thus, according to the second configuration, when the necessary active power Ptoad of the at least one electrical load 200 does not exceed the limit apparent power $nm. The auxiliary network 120 only compensates a portion of the reactive power of the main network 110, as shown in the intervals [0.5; 0.8] and [1.4; 1.6] of the graph of [Fig.6].

[0189] However, in the third configuration, the necessary active power P^ad of the at least one electrical load 200 exceeds the limit apparent power Shm. It is then possible to observe at the level of the auxiliary network 120 the fact that the auxiliary network 120 compensates, by means of the converter 122, all the reactive power of the main network 110, because of the regulation to 0 of the reactive power value in the main network 110 and provides the additional active power necessary to limit the network as illustrated on the interval [0.8; 1.4] of the graph of [Fig.6].

[0190] The power supply method 1, and the power supply device which applies the power supply method 1, thus have the advantage of making it possible to limit the powers of the main network 110, therefore seen by the electrical machine. It is then possible to size the electrical machines that are sources of alternating current such as alternators as precisely as possible to maintain average usage powers since the auxiliary network 120 makes it possible to cope with the occasional overloads subjected to the main network 110.

[0191] The solution is not intrusive and is completely dissociated from the control method of the main network 110.

[0192] The linearization strategy 1000 makes it possible to reduce the energy requirement of the 121 HVDC electrical energy storage element and therefore to reduce its mass on networks comprising inductive loads. < / q>

Claims

1. Claims Method for supplying (1) electrical energy to at least one electrical load (200) in an aircraft electrical system (300), the aircraft electrical system (300) comprising a main network (110) and an auxiliary network (120), the main network (110) comprising: • at least one alternating voltage source (111) by mechanical sampling on a drive system (112) connected to a current generation control unit (113), the alternating voltage source (111) being connected to the at least one electrical load (200), the auxiliary network (120) comprising: • at least one electrical energy storage assembly (121), configured to provide an energy supplement to the at least one electrical load (200), • a converter (122) arranged between the electrical energy storage assembly (121) and the at least one electrical load (200), configured to convert a direct current into an alternating current, • a converter control module (123), configured to measure a voltage between the at least one alternating voltage source (111) and the at least one electrical load (200) and to measure an electrical voltage between the converter (122) and the at least one electrical load (200), the feeding method (1) comprising the following steps: - Measurement (10) of a first voltage between the at least one alternating voltage source (111) and the at least one electrical load (200) and of a first current between the at least one alternating voltage source (111) and the at least one electrical load (200), - Measurement (20) of a second voltage between the converter (122) and the at least one electrical load (200) and of a second current between the converter (122) and the at least one electrical load (200), - Calculation (30) of an apparent power value S in the main network (110), - Determination (40) of an active power value P and reactive power Q, - Estimation (72) of a necessary power value SL(Kld, of a necessary active power value Ppoad and of a necessary reactive power value Q, . at least one r Loaa electrical load (200), the necessary power value ^Load representing the power value to be supplied to the at least one electrical load (200), the necessary power value SLoad being composed of the necessary active power value PlckuI and the necessary reactive power value ^Load' - If the detected necessary power value SLoad is greater than the apparent power S of the main network (110), injection (75) of a reactive power supplement Qsupp and / or an active power supplement Psupp from the auxiliary network (120) into the main network (110).

2. A power supply method (1) according to claim 1, wherein the step of determining (40) an active power and a reactive power comprises the following steps: - Observation (45) of the characteristics of the main network (110) and the auxiliary network (120), - Transformation (50) of the active power value P and the reactive power value Q calculated according to a Park transformation, - Decoupling (60) of the transformed active power value P and the transformed reactive power value Q, - Calculation (70) of an active power value P in the main network (110), - Calculation (70') of a reactive power value Q in the main network (110),

3. Feeding method (1) according to one of claims 1 or 2, comprising the following steps: - If the estimated necessary active power value PLoad is lower than the apparent power S of the main network (110), injection (750) of a reactive power supplement Qsupp from the auxiliary network (120) into the main network (110), - Otherwise, injection (752) of a reactive power supplement Qsupp from the auxiliary network (120) into the main network (110) and of an active power supplement Psupp from the auxiliary network (120) into the main network (110).

4. Power supply method (1) according to one of claims 1 to 3, comprising a first strategy for linearizing the active power P and the reactive power Q, the first linearization strategy consisting of defining a reference active power value Pref and a reference reactive power value Qref, the reference active power value Pre f being greater than the active power value P and the reference reactive power value Qref being greater than the reactive power value Q.

5. Power supply method (1) according to claim 3, comprising a second strategy for linearizing the active power P and the reactive power Q, the second linearization strategy consisting of defining a reference active power value Pref and a reference reactive power value Qref, the reference active power value Pref being greater than the active power value P and the reference reactive power value Qrej being less than the reactive power value Q.

6. A power supply method (1) according to claim 3 or 5, comprising a third linearization strategy of the active power P and the reactive power Q, the third linearization strategy consisting of a definition of the reference active power value Pref and the reference reactive power value Qref, the reference active power value Pref being less than the active power value P and the reference reactive power value Qref being less than the reactive power value Q.

7. Device (100) for supplying electrical energy to at least one electrical load (200) in an aircraft electrical system (300), the aircraft electrical system (300) comprising a main network (110) and an auxiliary network (120), the main network (110) comprising: • at least one alternating voltage source (111) by mechanical sampling on a drive system (112) connected to a current generation control unit (113), the at least one alternating voltage source (111) being connected to the at least one electrical load (200), the auxiliary network (120) comprising: • at least one electrical energy storage assembly (121), configured to supply direct current to the at least one electrical load (200), • a converter (122) arranged between the electrical energy storage assembly (121) and the at least one electrical load (200), configured to convert a direct voltage into an alternating voltage, • a converter control module (123), configured to measure a voltage and an intensity between the at least one alternating voltage source (111) and the at least one electrical load (200) and to measure an electrical voltage and an intensity between the converter (122) and the at least one electrical load (200),the control module (123) being configured to inject a reactive power supplement Qmpp and / or an active power supplement Psupp from the auxiliary network (120) into the main network (110) if a necessary power value SLoad for the at least one electrical load (200) is greater than an apparent power value S of the main network (110).,

8. The power supply device (100) of claim 7, wherein the at least one electrical energy storage assembly (121) is a battery.

9. A power supply device (100) according to claim 7 or 8, wherein the main network (110) and the auxiliary network (120) are three-phase networks.

10. A power supply device (100) according to one of claims 7 to 9, wherein the at least one alternating voltage source (111) is an al- ternator.

11. Power supply device (100) according to one of claims 7 to 10, comprising a filter (124) arranged between the converter (122) and the at least one electrical load (200).

12. A power supply device (100) according to one of claims 7 to 11, comprising a hybridization contactor (126) configured to couple and decouple the main network (110) and the auxiliary network (120).

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