Method for regulating an electric machine in motor mode by parallel hybridisation of an auxiliary electrical network

Abstract

The invention relates to an electrical system for an aircraft, comprising a main network (110) and an auxiliary network (120) connected to the main network (110) and a device for regulating the rotary electric machine (111), the regulating device comprising: - a first regulating member (131) for regulating the voltage of the main network (110) connected to the control unit (113), the first regulating member (131) being configured to regulate the induction current of the rotor of the rotary electric machine (111); - a second member (132) for regulating the current at the terminals of the rotary electric machine (111) connected to the control module (123), the second regulating member (132) being configured to control the current generated by the converter (122), the electrical system being configured to adopt: - a generator configuration in which the rotary electric machine (111) transmits an electric current to the at least one electric component (200); and - a motor configuration in which the value of the current at the output of the converter (122) is greater than the value of the current of the at least one electric component (200), the electrical system switching from the generator configuration to the motor configuration, and vice versa, by controlling the regulating device (123).

Description

DESCRIPTION Title of the invention: Method for controlling an electric machine in motor mode by parallel hybridization of an auxiliary electrical network.

[0001] The invention relates to the field of on-board electrical systems and rotating electrical machines generating electrical energy for consuming components inside an aircraft. More generally, the invention relates to the field of electrical networks and hybridization.

[0002] The invention relates to an electrical system for an aircraft comprising in particular a device for controlling an electrical machine and at least one electrical energy storage assembly. More particularly, the invention is an electrical system comprising a device for parallel hybridization of single- or multi-stage electrical machines with a static generator making it possible to provide engine torque and meet the generation needs of the aircraft network.

[0003] The electrical machines of an aircraft are alternators - motors. The motor function is currently only used in the context of a reactor start (traditionally by a ground-based energy source). Recent developments in energy storage systems make it possible to consider re-boarding new energy sources in aircraft. These will make it possible to perform hybrid functions of these machines during certain flight phases in order to optimize the reactor's fuel consumption for low-efficiency regimes.

[0004] In addition, in-flight turbulence causes variations in mechanical power which force the aircraft's reactors to be oversized in order to avoid reaching an unstable regime.

[0005] Furthermore, aircraft today increasingly carry electrical components, including inverters to perform the electric start function. However, these inverters are not reused after the flight and can therefore be considered dead weight.

[0006] Finally, the aircraft system's power grid, when the components are in current generation mode, must be permanently powered. However, this requirement is a barrier to hybridization solutions because

[0007] The main rotating electrical machines cannot generate power to the aircraft electrical grid and provide torque to the engine at the same time.

[0008] Some documents such as EP 4087079 A1 address this issue in the aeronautics field. EP 4087079 A1 only allows for current regulation at the converter level in the aircraft network. However, since the load required in the aircraft network is variable, the power of the latter cannot be compensated by regulation. In other words, EP 4087079 A1 allows for regulation of the current at the converter output but does not provide information on a contribution from energy storage systems to the aircraft's rotating machinery.

[0009] Document WO 2016 / 133503 A1 proposes a device facilitating the starting of aircraft propulsion systems by means of a coupling between the mechanical drive systems and the rotating electrical machines of the aircraft. However, document WO 2016 / 133503 A1 proposes to relieve the transmission shaft from its main load, namely the propulsive torque, by transmitting engine torque assistance. However, in a starter mode as disclosed, the device according to document WO 2016 / 133503 A1 does not seek to maintain the network voltage in the aircraft at a certain value, which is essential during the flight phase of the aircraft.

[0010] The invention aims to overcome all or part of the problems mentioned above by proposing a device for controlling the power flows of rotating electrical machines by two separate controls: An initial control of the aircraft network voltage at a constant value by controlling the rotor current of the rotating electrical machine. A second control of the powers linked to the rotating electrical machine by the current source of the hybridization network connected in parallel with the main network.

[0011] To this end, the invention relates to an electrical system for aircraft comprising a main network and an auxiliary network connected to the main network, the main network comprising: A drive system, A rotating electrical machine connected to the drive system, the rotating electrical machine being connected to at least one electrical component, the rotating electrical machine comprising a rotor and a stator, the rotor being driven into motion by the drive system, A control unit for the rotating electrical machine, the auxiliary network comprising: at least one battery, supplying direct current to the at least one electrical component, a converter connected to the at least one battery and to the at least one electrical component, configured to convert the direct current into an alternating current, a control module of the converter connected to the converter, configured to measure a voltage between the rotating electrical machine and the at least one electrical component and to measure a voltage between the converter and the at least one electrical component, the electrical system further comprising a device for controlling the rotating electrical machine, the control device comprising: a first voltage control member of the main network connected to the control unit,the first control member being configured to control the induction current of the rotor of the rotating electrical machine so that the rotating electrical machine is maintained at an imposed rotation speed, a second control member for the current at the terminals of the rotating electrical machine connected to the control module, the second control member being configured to control the current generated by the converter when the induction current of the rotor of the rotating electrical machine is regulated by the first voltage control member of the main network, the electrical system being configured to take: a generator configuration in which the rotating electrical machine transmits an electric current to the at least one electrical component, and, a motor configuration in which the value of the current at the output of the converter is greater than the value of the current of the at least one electrical component, the electrical system switching from the generator configuration to the motor configuration, and vice versa, by controlling the control device.

[0012] The electrical system advantageously allows for the control of the flow of propulsive power, which is precisely allocated to the turbine, while maintaining the quality of current and voltage in the aircraft network for consumers. In addition, this control does not depend on the measurement of the angular position of the rotating machine, which can be restrictive.

[0013] According to one aspect of the invention, the drive system is a rotary drive system.

[0014] According to one aspect of the invention, the main network and the auxiliary network are three-phase networks.

[0015] According to one aspect of the invention, the electrical system comprises a filter disposed between the converter and the at least one electrical component.

[0016] According to one aspect of the invention, the converter is an inverter.

[0017] 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:

[0018] Figure 1 represents an electrical system for aircraft according to the invention,

[0019] Figure 2 represents a method of controlling the electrical system of Figure 1,

[0020] Figure 3 shows a schematic view of the current and voltage of the electrical system in a Fresnel diagram.

[0021] For the sake of clarity, the same elements will have the same references in the different figures.

[0022] Figure 1 shows an electrical system 100 for an aircraft. The electrical system 100 comprises at least two branches in parallel with each other. In other words, the electrical network 100 comprises a main network 110 and an auxiliary network 120.

[0023] The main network 110 comprises at least one alternating voltage source 111 by mechanical tapping on a drive system 112. The alternating voltage source 111 is a rotating electrical machine 111 with one or more stages. The rotating electrical machine 111 comprises a rotor 1110 and a stator 1111. The rotor 1110 is rotatable in the stator 1111 so as to generate an induction current towards at least one electrical component 200 connected to the electrical system 100 of the aircraft.

[0024] The rotating electrical machine 111 is thus connected, by means of its rotor, to the drive system 112 which makes it possible to drive the rotor of the rotating electrical machine 111 in rotation.

[0025] From then on, the rotating electrical machine 111 is in a current generating state. Indeed, the drive system 112 generates mechanical energy which is transferred to the rotor of the rotating electrical machine 111 which ensures a transformation of this mechanical energy into electrical energy, in the form of measurable current in the main network 110, in order to supply voltage to the at least one electrical component 200.

[0026] The rotating electrical machine 111 is also connected to a voltage control unit 113. The control unit 113 allows the rotating electrical machine 111 to be controlled so that the rotating electrical machine generates a fixed voltage regardless of the need of the electrical components 200 in the aircraft. The control unit 113 regulates the rotating electrical machine 111.

[0027] The auxiliary network 120 comprises at least one electrical energy storage assembly 121 configured to provide additional energy to the at least one electrical component 200 and capable of supplying direct current to the at least one electrical component 200. In other words, the electrical energy storage assembly 121 is connected to the at least one electrical component 200 and supplies direct electric current to the at least one electrical component 200.

[0028] The electrical energy storage unit 121 is preferably a battery 121. However, any device for storing or generating a current continuous can be considered such as a Ram air turbine for example. In the remainder of the description, the electrical energy storage unit 121 is a battery 121.

[0029] The auxiliary network 120 also comprises a converter 122 disposed between the battery 121 and the at least one electrical component 200, configured to convert the direct current of the battery 121 into an alternating current. The battery 121 thus provides a direct current to the converter 122 which converts it.

[0030] The auxiliary network 120 also comprises a control module 123 of the converter 122, configured to measure a voltage between the rotating electrical machine 111 and the at least one electrical component 200 and to measure an electrical voltage between the converter 122 and the at least one electrical component 200. The control module 123 of the converter 122 is also capable of measuring the electrical current between the rotating electrical machine 111 and the at least one electrical component 200 and of measuring an electrical current between the converter 122 and the at least one electrical component 200. The control module 123 is connected to the converter 122.

[0031] The main network 110 and the auxiliary network 120 are therefore two separate electrical networks, both connected to at least one electrical component 200.

[0032] Optionally, the auxiliary network 120 may also comprise a filter 124 disposed between the converter 122 and the at least one electrical component 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.

[0033] The electrical system 100 further comprises a control device 130 for the rotating electrical machine 111. The control device 130 for the rotating electrical machine 111 comprises a first control member 131 for controlling the voltage of the main network 110 connected to the control unit 113. The first control member 131 is configured to control the rotor induction current of the rotating electrical machine 111 so as to vary or maintain the output voltage of the rotating electrical machine 111. Indeed, the electromotive force generated by the rotating electrical machine 111 varies proportionally to the speed and the induction current. Thus, when the rotation speed imposed by the reactor varies, the output voltage of the electrical machine can be controlled and kept constant by acting directly on the rotor induction current.

[0034] In other words, the voltage of the rotating electrical machine, and more generally of the electrical system 100, depends on the drive speed of the drive system 112, that is to say the rotation speed transmitted by the drive system 112, the current in the main network 110, at the terminals of the rotating electrical machine 111 and the induction current of the rotor of the rotating electrical machine. Indeed, the voltage V P0R of the electrical system 100 depends on two equations: The voltage drop in the stator windings of the rotating electrical machine 111 which depends on the current in the main network 110:

[0036] Where V FEM represents an electromotive force value in Volts, R s represents the electrical resistance of the rotating electrical machine 111 in Ohm, I prin represents the current value at the rotating electrical machine 111, L srepresents the stator inductance of the rotating electric machine in Henry and V P0R represents the voltage value in the electrical system 100. And the modulus of the electromotive force V FEM dependent on electrical speed o> eiec , of the rotor induction current I f in Amperes and current to the rotating electric machine after transformation in a Park frame:

[0038] Where M a represents a mutual inductance value of the rotating electric machine 111 in Henry, L d and / ^represent the value of the inductance of the rotating electrical machine 111 after a change of reference frame by means of a Park transform respectively supported along the d axis in the Park reference frame and supported along the q axis in the Park reference frame and I dprinrepresents the current value at the rotating electrical machine 111 after changing the reference frame to the Park reference frame supported along the d axis of the Park reference frame.

[0039] Considering these two equations (1) and (2), it is therefore possible to link the voltage value V P0R in the electrical system 100 at the electrical speed o> eiec , aware of the prin of the main network 110 and to the rotor induction current l f .

[0040] Thus the first control member 131 makes it possible to adjust the control of the rotor induction current to maintain the voltage value V P0R in the electrical system 100 to a constant value by regulation to compensate for variations in current l prin and the electric speed, a> e(ec without having to know their value.

[0041] Maintaining a constant voltage in the main network 110 and in the electrical system 100 by acting on the current of the rotor of the rotating electrical machine 111 thus has the advantage of maintaining an electrical potential for the at least one electrical component 200 and of avoiding any malfunction of the at least one electrical component 200 due to an unwanted undervoltage.

[0042] The control device 130 of the rotating electrical machine 111 also comprises a second control member 132 for controlling the current at the terminals of the rotating electrical machine 111. The second control member 132 is connected to the control module 123. The second control member 132 is configured to control the current generated by the converter 122. Indeed, the power of the main network 110 is a function of the voltage in the electrical system 100 and of the current in the main network 110. However, as stated previously, the voltage in the electrical system 100 is kept constant by the action of the first control member 131 of the rotating electrical machine 111. Thus it is possible to control the power and the value of the current in the main network 110 by injecting a current greater than the need of the consumers, namely the at least one electrical component 200, with the static generator, namely the battery 121.The auxiliary network 120 and the at least one electrical component 200 then form a reversible source of power from the point of view of the rotating electrical machine.

[0043] The battery 121 and the converter 122 then make it possible to meet the needs of the electrical network, i.e. the at least one electrical component 200, without knowing the current consumed I c by at least one electrical component 200.

[0044] More precisely, the second control member 132 makes it possible to act on the auxiliary network 120 and on the battery 121 so that the battery 121 generates a predefined current value. Thus, the second control member 132 can control the battery 21 so that the battery 21 increases the current in the auxiliary network 120, by increasing the value of the current generated, or decrease the current in the auxiliary network 120, by decreasing the value of the current generated by the battery 121.

[0045] In this way, it is possible to control the current and therefore the power of the main network 110 by varying the current in the auxiliary network 120. Indeed, the value of the current in the electrical network 100, which supplies the at least one electrical component 200, is defined as the sum of the current in the main network 110, generated by the rotating electrical machine 111, and the current in the auxiliary network 120, converted by the converter 122.

[0046] In other words, the value of the current measured at the at least one electrical component 200 can be defined according to the following formula:

[0047] L c Iprin " rate

[0048] Yes c represents the value of the current to the at least one electrical component 200, I prin represents the value of the current in the main network 110, that is to say the value of the current generated by the rotating electrical machine 111 and the auxrepresents the value of the current in the auxiliary network 120, generated by the converter 122.

[0049] However, the current requirement of the at least one electrical component being estimable, varying the current in the auxiliary network 120 makes it possible to vary the value of the current in the main network 110 generated by the rotating electrical machine 111. The current requirement of the at least one electrical component 200 is not constant. However, the control member 132 remains independent of this variation.

[0050] In other words, the second control member 132 makes it possible to force the battery 121 and the converter 122 to generate a greater quantity of current in the auxiliary network 120 to compensate for the variation in current in the at least one electrical component 200. This additional input then impacts the value of the current in the main network 110 and more particularly the rotating electrical machine 111, the current generation of which is reduced.

[0051] Thus, for a value of current I c to the at least one electrical component 200, the increase in the value of the current l aux to the auxiliary network 120 induces a decrease in the current value / prin in the main network 1 10.

[0052] And, when the value of the current l aux to the auxiliary network 120 is greater than or equal to the value of the current I c to the at least one electrical component 200, then the value of the current / prinin the main network 1 10 becomes less than or equal to zero.

[0053] Therefore, it is possible to observe in the main network 1 10 a reversal of the direction of the current so that the rotating electrical machine 1 1 1 is in a motor state and absorbs current from the auxiliary network 120 to generate additional torque for the drive system 1 12.

[0054] In other words, the transmission of energy is reversed and the rotating electrical machine 1 1 1 consumes the electrical energy, namely the current in the main network 1 10 present in excess, so as to provide mechanical energy towards the drive system 1 12. The rotating electrical machine 1 11 then switches from a generator state to a motor state.

[0055] The second control member 132 therefore makes it possible to switch the rotating electrical machine 1 1 1 from a current generator state to a motor state and vice versa by controlling the current at the output of the converter 122 and in particular by increasing the value of the current / au% to the auxiliary network 120 in relation to the current value / p n in the main network 1 10.

[0056] In fact, by increasing the value of the current / au% to the auxiliary network 120 so as to be greater than the value of the current I c to the at least one electrical component 200, then the direction of the current in the main network 110 is reversed and the state of the rotating electrical machine 1 1 1 switches from current generator to motor. And, by decreasing the value of the current / au% to the auxiliary network 120 so as to be greater than the value of the current I cto the at least one electrical component 200, the second control member 132 then allows the rotating electrical machine 111 to switch from a motor state to a current generator state to compensate for the reduction in the current generated in the auxiliary network 120.

[0057] The electrical system 100 is thus configured to take: a generator configuration in which the rotating electrical machine 111 transmits an electric current to the at least one electrical component 200, and a motor configuration in which the value of the current at the output of the converter 122 is greater than the value of the current I c to at least one electrical component 200.

[0058] In other words, in the generator configuration of the electrical system 100, the value of the current I aux to the auxiliary network 120 is lower than the value of the current I cto the at least one electrical component 200, the rotating electrical machine 111 is therefore in a current generating state and the transmission of energy is done from the drive system 112 to the main network 110 via the rotating electrical machine 111 which transforms mechanical energy and electrical energy.

[0059] And, when the electrical system 100 in the motor configuration, the value of the current I aux to the auxiliary network 120 is greater than the value of the current I c to the at least one electrical component 200, the rotating electrical machine 111 is therefore in a motor state and the transmission of energy is done from the main network 110 to the drive system 112 via the rotating electrical machine 111 which transforms electrical energy and mechanical energy.

[0060] Also, in these two configurations, motor or generator, the electrical speed of the rotating electrical machine 111 is variable but remains imposed by the drive system 112 while the voltage is kept constant positive by action of the first control member 131. The power flows are therefore determined by the value of the currents in the electrical system 100. By analogy, the drive system 112 is a source of positive speed while the electrical machine is a reversible source of torque.

[0061] The electrical system 100 then switches from the generator configuration to the motor configuration, and vice versa, by controlling the control device 130, and more precisely the first control member 131 and the second control member 132.

[0062] Thus, a switching current value at the converter 122 can be identified, making it possible to observe the switching of the electrical machine from the current generating state to the motor state and vice versa, and therefore of the electrical system. 100 from generator configuration to motor configuration and vice versa. This switching current value is a current value I aux to the predetermined auxiliary network 120. Ideally, this value of switching current in the auxiliary network is equal to the value of the current I c to at least one electrical component 200.

[0063] The fact of fixing the voltage in the main network 110 by the action of the first control member 131 thus has the advantage of not impacting the at least one electrical component 200 in its operation during the configuration switch between the motor or generator configuration operated by the action of the second control member 132. The control device 130 then acts in two complementary and distinct actions, an assurance of having a fixed voltage for the at least one electrical component 200 before ensuring a change of configuration in the electrical system 100, and particularly at the level of the rotating electrical machine 111.

[0064] Advantageously, the drive system 112 is a rotary drive system such as a turbine. This type of drive system has the advantage of not requiring any conversion of motion between the rotary motion of the rotary drive system and the rotation of the rotor of the rotating electrical machine 111.

[0065] Alternatively, a transverse drive system may be envisaged with a device for converting the generated force into a driving torque of the rotor of the rotating electrical machine 111.

[0066] Optionally, the main network 110 and the auxiliary network 120 are three-phase networks. Alternatively, the main network 110 and the auxiliary network 120 may be single-phase or polyphase networks.

[0067] As an indicative example, the converter 122 may be an inverter. However, any device for converting a direct current DC to an alternating current AC may be considered.

[0068] The invention also relates to a method 1 for controlling the electrical system 100 shown in Figure 2. The method 1 for controlling the electrical system 100 comprises two steps that can be implemented in parallel with each other, namely a step 2 for regulating the power in the main network 110 and a voltage regulation step 3 in the electrical system 100. The power regulation step 2 and the voltage regulation step 3 are two steps decorrelated from each other, so that it can be envisaged, depending on the need or the order, to implement one of the steps among the power regulation step 2 or the voltage regulation step 3 or even both simultaneously.

[0069] The power management step 2 comprises a first sub-step 10 of measuring a first voltage between the rotating electrical machine 111 and the at least one electrical component 200. It is also envisaged, during the measurement sub-step 10, to measure, during this measurement step 10, a first current value between the rotating electrical machine 111 and the at least one electrical component 200.

[0070] Following step 10, the power management step 2 comprises a sub-step 20 of measuring a second voltage between the converter 122 and the at least one electrical component 200. And, similarly to sub-step 10, it is also envisaged to measure, during this measurement sub-step 20, a second current value between the converter 122 and the at least one electrical component 200.

[0071] These two measurement sub-steps 10 and 20 are implemented by means of the control module 123. The measurement sub-steps 10 and 20 thus make it possible to know the electrical power, and in particular the value of the current in the main network 110, which the rotating electrical machine 111 can supply in real time.

[0072] Thus, following sub-step 10 and preferably, following measurement sub-steps 10 and 20, the power management step 2 comprises a sub-step 30 of calculating an apparent power value in the main network 110. The notion of apparent power is a maximum power value available to operate the at least one electrical component 200. The apparent power is the trigonometric sum of the active power and the reactive power.

[0073] Preferably, the apparent power can be defined according to the following formula:

[0075] Where P represents the value of active power in the main network 110 while Q represents the value of reactive power in the main network 110.

[0076] 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 one that is 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.

[0077] Alternatively, this calculation can be done using the following formula:

[0078] S = U eff * I eff for a single-phase network and S = 3 * V eff * i eff (2) for a three-phase network,

[0079] Where S represents the apparent power value available in the main network 110, U eff represents the effective voltage value measurable in the main network, and I eff represents the effective current value measurable in the main network. In a three-phase reference, V eff then represents the phase-neutral voltage value and i eff the effective phase current value.

[0080] However, any other means of calculating the value of the apparent power available in the main network 110 can be considered.

[0081] Furthermore, it may also be envisaged to directly measure this power value in addition to the voltage and current in the first network 110.

[0082] After calculating 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.

[0083] To do this, preferably, the determination step 40 comprises a sub-step 45 of observation of the physical characteristics of the main network 110 and of 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 of the auxiliary network 120 have the same frequency and the same phase.

[0084] To do this, the control method 1 applies a phase-locked loop or PLL function which ensures that the current and voltage to the main network 110 connected to the auxiliary network 120 have the same frequency and the same phase.

[0085] This is followed by a sub-step 50 of transformation 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 in the PLL reference frame. Therefore, in the Park vector reference in the PLL reference frame, the active power value P and the reactive power value Q are written according to the following formulas:

[0088] Where 'and g' represent the two axes of the Park vector frame in the PLL reference frame. V d , thus represents the value of the first voltage along the axis d' while I d, represents the value of the first current along the axis d'. And, V q , thus represents the value of the first voltage along the g' axis while I q , represents the value of the first current along the q' axis.

[0089] This is followed by a sub-step 60 of decoupling 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, this time in the PLL reference frame, which, by Park transform in the PLL reference frame, imposes the following condition:

[0090] V q , = 0

[0091] In other words, the PLL function allows to determine an angle imposing the voltage value on the axis of the PLL vector reference q' such that Vq' = 0.

[0092] For information purposes, the PLL function used during sub-step 45 may preferably be identical to the PLL function of the decoupling sub-step 60.

[0093] The rotating electrical machine frame (c / ,q) and the PLL frame (cf, q') both come from Park transforms of the three-phase frame of the rotating electrical machine. However, these two frames have different functions. The rotating electrical machine frame (d,q) allows, by means of the Park transformation, to carry the power flows only on a single axis of the frame so as to facilitate the control of the rotating electrical machine 111, while the PLL frame (cf, q') allows the voltage in the electrical system 100 to be carried on a single axis of the frame making it possible to decouple the powers on a separate axis of the frame. The active power is then carried on the d' axis while the reactive power is carried on the g' axis.

[0094] The voltage management step 3 comprises a sub-step 300 of measuring a voltage at the rotating electrical machine 111. This is then followed by a sub-step 301 of measuring a rotor induction current at the rotating electrical machine 111. After having measured the voltage at the rotating electrical machine and the value of the induction current at the rotor of the rotating electrical machine during the sub-steps 300 and 301, the voltage management step 3 comprises a sub-step 302 of controlling the voltage in the electrical system 100.

[0095] In sub-step 302, the voltage in the electrical network 100 and in the rotating electrical machine 111 is maintained at a fixed voltage value. The voltage in the electrical system is then controlled.

[0096] Following sub-step 60, the power management step 2 comprises a step 70 for controlling the powers in the main network. This involves, during step 70, modifying the current value at the output of the converter 122. This control step 70 makes it possible to vary the value of the current I aux to the auxiliary network 120 around the switching current value allowing the electrical system to switch between the generator configuration and the motor configuration. However, as stated previously, the current to the at least one component 200 being the sum of the currents in the main network 110 and in the auxiliary network 120, increasing the value of the current in the auxiliary network induces a decrease in the value of the current in the main network 110, at the output of the rotating electrical machine 111. And, the power value being directly proportional to the value of the current, the decrease in the current in the main network 110 implies a decrease in the power value in the main network 110 until a reversal of the direction of the power to the rotating electrical machine 111. From then on, the current and the power in the main network 110 are controlled and the rotating electrical machine 111 can be controlled to switch from a current generator state to a motor state and vice versa.

[0097] Furthermore, in order not to impact the at least one electrical component 200 during a switch between the generator and motor configurations, it is necessary to fix the voltage in the electrical system 100 before varying the current and the power in the main network. Thus, the control method 1 may comprise a conditional step 310. The conditional step 310 thus requires that the implementation of the step 70 making it possible to control the current in the auxiliary network 120 and in the main network 110 is only permitted if the voltage in the electrical system 100 is fixed, that is to say after the implementation of the step 302.

[0098] Therefore, in order to guarantee proper operation of the at least one electrical component 200 during a switch between a motor configuration and a generator configuration or vice versa, a correlation link can be applied between the power control step 2 and the voltage control step 3, by means of the conditional step 310.

[0099] Finally, the control method 1 comprises, following step 70 and step 302, a step 80 of identifying the configuration of the electrical system 100 and the state of the rotating electrical machine 111. This identification step 80 makes it possible to know whether the rotating electrical machine 111 is in the current generator or motor state and whether the electrical system is in the current generator or motor configuration.

[0100] Now that it is understood that the voltage of the electrical system 100 is regulated at the rotating electrical machine 111 to a constant value and that the power of the electrical system 100 is regulated by the battery assembly 121 and converter 122 to impose only an active power, it is possible to observe the impact in terms of mechanical power at the level of the rotating electrical machine 111.

[0101] In a Fresnel diagram, represented in figure 3, it is possible to place the voltage V P0R of the electrical system 100 in phase opposition with the current l prin because the voltage V P0R is positive, the current l prin is negative and absorbed by the rotating electrical machine in motor configuration. The reactive power is, as previously indicated, zero.

[0102] The effective value of the electromotive force V PEM is then written:

[0107] As observed in the diagram of Figure 3, this voltage V FEM is projected onto the q axis of the Park frame, in accordance with Lenz Faraday's law.

[0108] The useful power P u brought to the machine is written as:

[0109] P u = -l q \V PEM \

[0110] With Iq the projection of the current I prin on the q axis of the reference frame. It is also possible to note by geometric construction that

[0111] / g = - \I prin \ cos(ô)

[0112] Thus the useful power P u is expressed as:

[0114] Therefore, the second control body 132 imposes a unit power factor on the main network 110, thus:

[0115] P u = Pelec 132 ~ p j stator

[0116] Where P e iec 132 represents the value of the active power imposed by the second control organ 132 and Pj stator represents the stator joule losses.

[0117] In addition, the regulated induction rotor current that the first control body 131 imposes is then defined as:

[0119] The transmitted power is therefore ensured by means of stator joule losses. Added to this are the iron losses and the rotor joule losses resulting from the variation of the rotor induction current I f .

[0120] The control device 130 operates within the magnetic saturation limits of the rotating electrical machine 111. Thus the motor torque power that can be developed is limited when the rotating electrical machine 111 is in motor configuration.

[0121] The invention therefore relates to a device 130 for controlling the power flows of a rotating electrical machine by two separate controls: A control of the voltage of the main network 110 at a constant value by the electronics for controlling the rotor current of the rotating electrical machine 111 carried out by the first control member 131, And a control of the powers, and more particularly of the currents, linked to the rotating electrical machine 111 by the converter 122 connected in parallel with the main network 111.

[0122] The rotating electrical machine 111 is thus regulated, by the first control member 131, in voltage in the main network 111 by controlling the rotor induction current. The output voltage of the rotating electrical machine 111 depends partly on the electromotive force of the rotor and therefore on this induction current. It is then possible to control the output voltage of the rotating electrical machine 111 by acting on the excitation current.

[0123] The power of the electrical system 100 being fixed by the loads, namely the at least one electrical component 200, the output currents of the converter 122 will gradually occur at the total power required by the loads. Therefore, the currents of the rotating electrical machine are harmed. Then, the sign of the currents in the rotating electrical machine 111 reverses in order to reverse the sign of the electromagnetic torque and pass into the motor quadrant.

[0124] The control device 130 has the advantage of having a control of the powers of the main network 110 which is non-intrusive with regard to the voltage regulation system. In addition, it is not necessary to multiply the electronic connections between the rotating electrical machine 111 and the converter 122.

[0125] The control device 130 also has the advantage of allowing operation of the rotating electrical machine 111 in motor mode while guaranteeing the generation of electrical power in the electrical system.

[0126] Finally, the control device 130 has the advantage of allowing the reuse of part of the power or even compensation of mechanical energy if necessary from electrical storage means such as batteries 121.

Claims

CLAIMS 1. Electrical system (100) for an aircraft comprising a main network (110) and an auxiliary network (120) connected to the main network (110), the main network (110) comprising: - A drive system (112), A rotating electrical machine (111) connected to the drive system (112), the rotating electrical machine (111) being connected to at least one electrical component (200), the rotating electrical machine (111) comprising a rotor and a stator, the rotor being driven into motion by the drive system (112), A control unit (113) of the rotating electrical machine (111), the auxiliary network (120) comprising: at least one battery (121), supplying direct current to the at least one electrical component (200), a converter (122) connected to the at least one battery (121) and to the at least one electrical component (200), configured to convert the direct current into an alternating current, - a control module (123) of the converter (122) connected to the converter (122), configured to measure a voltage between the rotating electrical machine (111) and the at least one electrical component (200) and to measure a voltage between the converter (122) and the at least one electrical component (200), the electrical system further comprising a device for controlling the rotating electrical machine (111), the control device comprising: a first control member (131) for controlling the voltage of the main network (110) connected to the control unit (113), the first control member (131) being configured to control the induction current of the rotor of the rotating electrical machine (111) so that the rotating electrical machine (111) is maintained at an imposed rotation speed, a second control member (132) for controlling the current at the terminals of the rotating electrical machine (111) connected to the control module (123),the second control member (132) being configured to control the current generated by the converter (122) when the induction current of the rotor of the rotating electrical machine (111) is regulated by the first control member (131) of the voltage of the main network (110), the electrical system being configured to take: a generator configuration in which the rotating electrical machine (111) transmits an electric current to the at least one electrical component (200), and, a motor configuration in which the value of the current at the output of the converter (122) is greater than the value of the current of the at least one electrical component (200), the electrical system switching from the generator configuration to the motor configuration, and vice versa, by controlling the control device (123).

2. An aircraft electrical system (100) according to claim 1, wherein the drive system (112) is a rotary drive system.

3. An aircraft electrical system (100) according to claim 1 or 2, wherein the main network (110) and the auxiliary network (120) are three-phase networks.

4. Electrical system for aircraft (100) according to one of claims 1 to 3, comprising a filter (124) arranged between the converter (122) and the at least one electrical component (200).

5. Electrical system for aircraft (100) according to one of claims 1 to 4, in which the converter (122) is an inverter.

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