Hybrid electrical system for powering an aircraft's electrical equipment from a turbomachine

Abstract

Hybrid electrical system for powering aircraft electrical equipment from a turbomachine. Hybrid electrical system (8) for powering aircraft electrical equipment from a turbomachine (1) comprising a high-pressure shaft (7) and a low-pressure shaft (3), the system (8) comprising a control unit (20), two electric machines (9, 10) each with two windings, and two electrical distribution control units (12) connected at their output to a high-voltage DC power network (16) and to electrical loads (14), one of the machines (9) being connected to the high-pressure shaft (7) and the other machine (10) being connected to the low-pressure shaft (3). And, for each control unit (12), a first bidirectional DC-AC converter (13) connected between a winding of the first machine (9) and the control unit (12), and a second bidirectional DC-AC converter (15) connected between a winding of the second machine (10) and the control unit (12).Each control unit (12) comprises a continuous high-voltage battery (17) and a third bidirectional DC-DC converter (18) connected between the battery (17) and the control unit (12). The control unit (20) commands the three converters (13, 15, 18) to maintain the voltage quality of the network (16) within a voltage range. See Fig. 1 for abbreviations.

Description

Title of the invention: Hybrid electrical system for powering electrical equipment of an aircraft from a turbine technical field

[0001] The invention relates to the internal hybridization of a turbomachine for electrified aircraft, and more particularly to an electric hybrid system for supplying electrical equipment of an aircraft from a turbomachine. Previous technique

[0002] Climate change is a major concern for many legislative and regulatory bodies worldwide. Indeed, various restrictions on carbon emissions have been, are being, or will be adopted by various states. In particular, an ambitious standard applies to both new types of aircraft and those already in service, requiring the implementation of technological solutions to bring them into compliance with current regulations. Civil aviation has been actively working for several years now to contribute to the fight against climate change.

[0003] Technological research efforts have already led to very significant improvements in the environmental performance of aircraft. The Applicant takes into account the factors impacting all phases of design and development in order to obtain aeronautical components and products that are less energy-intensive, more environmentally friendly, and whose integration and use in civil aviation have moderate environmental consequences, with the aim of improving the energy efficiency of aircraft.

[0004] Consequently, the Applicant is constantly working to reduce its negative climate impact by using methods and operating virtuous development and manufacturing processes that minimize greenhouse gas emissions to the minimum possible in order to reduce the environmental footprint of its activity.

[0005] This sustained research and development work focuses on new generations of aircraft engines, the weight reduction of aircraft, in particular through the materials used and lighter on-board equipment, the development of the use of electrical technologies to provide propulsion, and, as essential complements to technological progress, aviation biofuels.

[0006] In the context of aircraft propulsion, the hybridization of a turbomachine is achieved using an electrical system that interfaces between the mechanical shafts of the turbomachine and the aircraft's electrical network. This electrical system must be able to perform the following functions, namely, power generation, turbomachine assistance, turbomachine starting, and reconfiguration in the event of failures.

[0007] Such an electrical system must provide a stable and reliable power supply to the aircraft's electrical distribution system by drawing power from the low-pressure and high-pressure sections of the turbomachine (power generation). It must also allow power to be injected into or drawn from the high-pressure and / or low-pressure sections according to the instructions received by the turbomachine's computer (turbomachine assistance). Furthermore, during turbomachine startup, it must provide sufficient mechanical power to the high-pressure shaft, this power potentially originating from a source external to the grid (turbomachine start-up). Finally, the system must allow for reconfiguration in the event of an internal or external failure.

[0008] The distribution architecture within the scope of the invention corresponds to an internal hybridization scheme for a turbomachine based on parallel-connected continuous power channels (DC channels). These DC channels comprise an electric machine (often a permanent magnet synchronous machine) coupled to a controlled power electronics converter (with one channel for the high-pressure shaft and one channel for the low-pressure shaft) supplying a DC bus. Power converters thus interface between the electric machines and the grid or DC bus. An external source such as an auxiliary power unit (APU) or a battery can also be connected to this DC bus.

[0009] In more detail, such an internal DC power bus hybridization system classically comprises a first machine, of the permanent magnet synchronous (PMG) type, composed of two independent stator windings on the high-pressure shaft of the turbomachine, a first DC / AC converter connected to each stator winding of the first machine, a second machine, of the permanent magnet synchronous (PMG) type, composed of two independent stator windings on the low-pressure shaft of the turbomachine, a second bidirectional DC / AC converter connected to each stator winding of the second machine, and two power distribution units (PDMUs) putting the first converter and the second converter in parallel on the same DC power bus and allowing the distribution of high-voltage direct current (HVDC) electrical energy to the aircraft and to the internal electrical loads of the turbomachine.The term "bidirectional DC / AC converter with stator winding" covers both a single bidirectional converter box and two unidirectional converter boxes (in two opposite directions).

[0010] One of the main functions of a power supply system is the generation of electrical power, that is to say, to provide a continuous electrical network ensuring network quality to the aircraft's electrical distribution by taking power from the low pressure or high pressure parts.

[0011] The hybridization of a turbomachine thus leads to the creation of an HVDC network with permanent magnet machines and power electronic converters in order to be able to inject and extract power on the low pressure and high pressure shafts, whereas current commercial aircraft only have the capacity to generate electrical power from the high pressure shaft.

[0012] However, to ensure grid quality with a continuous power generation system comprising permanent magnet machines and power electronic converters, it is necessary to be able to extract mechanical power with a high dynamic range (between 200 Hz and 2 kHz). However, with current commercial aircraft generators, which have a different topology (wound rotor machine) and supply an AC grid, the mechanical power extraction is slower (<20 Hz) to be acceptable in terms of grid quality.

[0013] Constant speed generators, by their construction, have natural mechanical damping, variable frequency generators (VFG) have presented mechanical problems on certain applications which have been solved by adding mechanical damping in the VFG generator.

[0014] In addition, the high pressure and low pressure mechanical shafts on existing and developing turbomachines are quite flexible and have resonance frequency modes in the range [10-100Hz].

[0015] A "flexible shaft" is defined as a shaft with low stiffness and low damping; in other words, a "flexible" shaft. If we draw an analogy with linear (rather than rotor) displacement, this is akin to having a spring on the mechanical chain. This is a known problem in modern turbomachinery: the electric generator is stiff relative to the turbomachine's mechanical shaft, and when the electric generator draws torque, this causes torque ripples on the turbomachine's mechanical shaft.

[0016] The difficulty of implementing a high-frequency mechanical sampling comes from the frequency modes of the high-pressure and low-pressure shafts which can be excited, causing an oscillation of the shaft which can lead to shaft breakage if no damping is present on the mechanical shaft chain.

[0017] This may present an infeasibility of implementing such an electrical hybridization system with electric machines on flexible shafts. Description of the invention

[0018] The invention, particularly advantageous for the purpose of reducing the environmental impact of aircraft, aims to provide a hybrid electrical system for supplying electrical equipment of an aircraft from a turbomachine enabling the hybridization functions to be performed while limiting or even eliminating the risks of breakage of the high-pressure and low-pressure shafts, even with flexible shafts, and maintaining a sufficient voltage quality on the aircraft's high-voltage network.

[0019] In a first aspect of the invention, a hybrid electrical power supply system is proposed for supplying electrical equipment of an aircraft from an aircraft turbomachine comprising a high-pressure shaft and a low-pressure shaft. The power supply system comprises at least one control unit, two permanent magnet electric machines each comprising two stator windings, and two electrical distribution control units, one of the electric machines being intended to be mechanically connected to the high-pressure shaft of the turbomachine and the other electric machine being intended to be mechanically connected to the low-pressure shaft of the turbomachine. These electrical distribution control units are intended to be connected at their output to a high-voltage DC electrical network of the aircraft and to electrical loads of the turbomachine.The system further comprises, for each electrical distribution control unit, a first bidirectional DC-AC converter connected between a stator winding of the first electrical machine and said electrical distribution control unit, and a second bidirectional DC-AC converter connected between a stator winding of the second electrical machine and said electrical distribution control unit.

[0020] According to a general feature of the invention, for each power distribution control unit, the system further comprises a high-voltage DC battery and a third bidirectional DC-DC converter connected between the battery and said power distribution control unit. Furthermore, according to another general feature of the invention, said at least one control unit of the system is connected to the first, second, and third converters, and configured to control the first, second, and third converters to maintain a high-voltage DC power grid voltage quality within a given range, which can be defined by a minimum voltage threshold and a maximum voltage threshold.

[0021] The hybrid electrical power supply system according to the invention makes it possible to control the voltage of a hybrid electrical network using two permanent magnet synchronous machines coupled respectively to the high-pressure shaft and the low-pressure shaft of the turbomachine and a battery. This is achieved while ensuring network quality and respecting the mechanical constraints and limitations of the low-pressure shafts and high pressure turbomachine.

[0022] This architecture thus makes it possible to perform the hybridization functions of the turbomachine, namely, power generation, turbomachine assistance and turbomachine starting, while, on the one hand, taking into account the mechanical constraints of the low pressure and high pressure shafts of the turbomachine to avoid a risk of breakage and, on the other hand, maintaining a sufficient quality for the network voltage.

[0023] The architecture makes it possible to generate power, that is, to provide a continuous electrical network while ensuring network quality to the aircraft's electrical distribution system by drawing power from the low-pressure and / or high-pressure sections and / or from the battery provided by the architecture, depending on the optimization of battery charging or the turbomachine's fuel consumption. The battery manages the voltage quality of the network at high frequencies or at frequencies unattainable by the machines due to mechanical constraints.

[0024] In terms of turbomachine assistance, the architecture allows power to be injected or extracted from both the high-pressure shaft and the low-pressure shaft according to the instructions received by the system control unit.

[0025] During turbomachine start-up, the architecture allows the network to supply power to the high-pressure and / or low-pressure shafts. This power can come from a source external to the network or directly from the battery.

[0026] In a first aspect of the system, the first converter, the second converter and the third converter may each include an internal control board comprising a regulation stage and a control stage, the regulation stage being configured to receive a power setpoint or a voltage setpoint generated by the control unit and convert the power setpoint or the voltage setpoint into a current setpoint, and the control stage being configured to convert said current setpoint of the regulation stage into a control setpoint of the converter, the power setpoints being configured to control a power draw or injection on at least one of the shafts of the turbomachine or on the battery, and the voltage setpoints being configured to control the maintenance of a voltage quality of the high voltage DC power grid within a given template (minimum and maximum thresholds).

[0027] In a second aspect of the system, the regulation stage and the control stage each include at least one control loop of the proportional, or proportional-integral, or proportional-integral-derivative type.

[0028] In a third aspect of the system, the regulation stage of the internal control board of the first converter and the regulation stage of the internal board of The control of the second converter may each further include an electronic limiting circuit configured to adapt the current setpoint from a torque setpoint to be delivered which depends on the mechanical limits of the shaft of the turbine machine to which the converter is associated via the electric machine in order to eliminate the risks of oscillation, natural mode excitation and mechanical breakage.

[0029] The electronic limiting circuit for adapting the current setpoint according to the torque setpoint can be a torque slope limiter, a low-pass filter, a band-stop filter centered on the eigenmodes of the mechanical shaft or any other algorithm allowing the suppression of mechanical breakages.

[0030] The electronic limiting circuit can be an analog electronic circuit or a digital electrical circuit made from logic modules.

[0031] Adding an algorithm that transforms the torque setpoint, from which the current setpoint is derived, to adapt to the mechanical limitations of the shaft restricts the performance of the voltage and power regulation loops and, on its own, cannot achieve the desired network quality. The addition of the battery with the third converter and the converter control solves this problem, as the combination of the battery and the third converter has the capacity to control a current without dynamic limitations.

[0032] According to another aspect of the invention, a turbomachine for an aircraft is proposed comprising a high-pressure shaft and a low-pressure shaft and a power supply system for electrical equipment of an aircraft as defined above.

[0033] According to yet another aspect of the invention, an aircraft is proposed comprising at least one turbomachine as defined above.

[0034] According to yet another aspect of the invention, a method for controlling the hybrid electrical power supply system as defined above is proposed. The method comprises: - a voltage command received by at least one of the converters, including the first converter, the second converter, and the third converter, - a power setpoint received by at least one of the converters among the first converter, the second converter and the third converter, - a current setpoint generated for the first converter, a current setpoint for the second converter, and a current setpoint for the third converter, each current setpoint being generated from the received voltage or power setpoint, - a transformation of each current setpoint into a control setpoint for the corresponding converter, said at least one received power setpoint being configured to control a power draw or injection on at least one of the tur- shafts bomachine or on the battery, and said at least one received voltage setpoint being configured to control the maintenance of a high voltage DC electrical network voltage quality within a given voltage template.

[0035] In a first embodiment of the control method, the current setpoint for the third converter generated from said at least one received voltage setpoint can be configured to operate the third converter at high frequency to manage transient phases using the battery, and the setpoints of the first converter and the second converter generated from said at least one power setpoint can be configured to operate the first converter and the second converter at low frequency to optimize the operation of the turbomachine.

[0036] Thus, the battery can control, using proportional-integral correction, the DC voltage of the grid with the desired grid quality without limitation, and the electrical machines can follow the received power commands. This makes it possible to guarantee grid quality with a converter, the battery managing all grid transients (load inrush or load release) to maintain a DC voltage, and the lower-frequency power commands are intended to allow the first and second converters to control the first and second electrical machines in order to optimize the operating point of the turbomachine and therefore the turbomachine's fuel consumption, while also allowing for optimization of the battery charge if necessary by requesting the machines to generate energy for the grid.

[0037] In addition, the generation of current setpoints and the transformation of current setpoints into converter control setpoints can each include proportional, or proportional-integral, or proportional-integral-derivative regulation.

[0038] In a second embodiment of the process, the generation of the current setpoint for the first converter may include a limitation of the setpoint based on the mechanical limits of the low-pressure shaft, and the generation of the current setpoint for the second converter includes a limitation of the setpoint based on the mechanical limits of the high-pressure shaft.

[0039] In a third embodiment of the method, the current setpoint generated for the first converter and the current setpoint generated for the second converter are configured to assist the third converter in maintaining a voltage quality of the high-voltage DC power grid within a given voltage template by controlling the first and second electrical machines to manage low-frequency transients.

[0040] Thus, one of the electrical machines controls the low DC voltage of the network frequency (bandwidth lower than the mechanical modes of the low-pressure shaft with a low-frequency proportional-integral controller), the battery regulates the rest to ensure the desired network quality using a proportional-derivative controller, and the other electric machine follows a received power setpoint.

[0041] This makes it possible to guarantee the quality of the network with the battery converter and to guarantee the main generation of the network from a low frequency machine in order to limit the current consumed on the battery and therefore optimize its charge.

[0042] The battery manages all high-frequency network transients (load inrush or load release) and one of the machines manages all low-frequency network transients (load inrush or load release) to maintain a continuous voltage. Brief description of the drawings

[0043] The invention will be better understood upon reading the following, by way of example but not limitation, with reference to the accompanying drawings in which:

[0044] [Fig-1] Figure [Fig.1] schematically presents a turbomachine of an aircraft equipped of a power supply system for aircraft electrical equipment according to a first embodiment of the invention.

[0045] [Fig.2] The [Fig.2] schematically illustrates a control card of one of the first or second converters of the power supply system of the [Fig.1].

[0046] [Fig.3] The [Fig.3] schematically illustrates a control card of one of the first or second converters of the power supply system of the [Fig.1].

[0047] [Fig.4] Fig.4 schematically presents a flowchart of a method for controlling the power supply system of [Fig.1] according to an implementation method of the invention. Description of the implementation methods

[0048] Figure 1 schematically illustrates a turbomachine of an aircraft equipped with a system for supplying electrical equipment of the aircraft according to an embodiment of the invention.

[0049] The turbomachine 1 comprises a blower 2 coupled to a low-pressure shaft 3, the blower 2 acting as a low-pressure compressor and the low-pressure shaft 3 also being coupled to a low-pressure turbine 4. The turbomachine 1 further comprises a high-pressure compressor 5 and a high-pressure turbine 6 coupled to a high-pressure shaft 7.

[0050] The turbomachine 1 further comprises an electrical power supply system 8 which is a hybrid electrical power supply system for electrical equipment. The power supply system 8 comprises a first electrical machine 9 and a second machine 10 electric, both of which are permanent magnet synchronous electric machines, and two electrical distribution control units (PDMUs) 12.

[0051] The first electric machine 9 is mechanically connected to the high-pressure shaft 7 of the turbomachine 1 and comprises two independent first stator windings. And the second electric machine 10 is mechanically connected to the low-pressure shaft 3 of the turbomachine 1 and comprises two independent second stator windings.

[0052] For each first stator winding of the first electric machine 9, the power supply system 8 includes a first bidirectional DC-AC power converter 13 electrically connected between the first stator winding and an electrical distribution control unit 12. Each first electrical converter 13 is connected to a different electrical distribution control unit 12.

[0053] For each second stator winding of the second electric machine 10, the power supply system 8 comprises a second bidirectional DC-AC power converter 15 electrically connected between the second electric machine 10 and a corresponding electrical distribution control unit 12. Each second power converter 15 is connected to a different electrical distribution control unit 12.

[0054] Each electrical distribution control unit 12 is connected at output to a main continuous electrical network 16 (HVDC) of the aircraft, on the one hand, and to electrical loads 14 of the turbomachine 1, on the other hand.

[0055] Thus, the architecture allows local domestic loads 14 of the turbomachine 1 to be supplied via the PDMU electrical distribution control units 12 and provides a possibility of drawing or injecting power on the high-pressure shaft 7 via the HVDC network 16.

[0056] The power supply system 8 further comprises, for each electrical distribution control unit 12, a battery 17 and a third electrical converter 18 electrically coupled between the battery 17 and an input of the electrical distribution control unit 12. The third electrical converter 18 is a bidirectional DC-DC power converter. Each assembly consisting of a battery 17 and a third electrical converter 18 is thus configured to supply direct current to the electrical distribution control unit 12 to which it is coupled.

[0057] The power supply system 8 includes an electronic control unit 20 electrically connected to each of the first converters 13, second converters 15, and third converters 18, as illustrated by the dashed control lines. The control unit 20 is configured to output power and / or voltage instructions to the different converters 13, 15, 18.

[0058] Figure 2 schematically illustrates a control card of one of the first converters 13 or second converters 15.

[0059] The first converter 13 and the second converter 15 each comprise an internal control board 30 having a regulation stage 31 and a control stage 32. The regulation stage 31 is configured to receive a power setpoint or a voltage setpoint, CP / T, generated by the control unit 20 and convert the power setpoint or voltage setpoint into a current setpoint, Ccurrent. And the control stage 32 is configured to convert the current setpoint of the regulation stage 31 into a converter control setpoint, Cconverted, for the first converter 13 or the second converter 15.

[0060] The power setpoints of the control unit 20 are configured to control a power draw or injection on at least one of the shafts among the low pressure shaft 3 and the high pressure shaft 7 of the turbomachine 1. And the voltage setpoints of the control unit 20 are configured to control the maintenance of a voltage quality of the high voltage DC power network 16 within a given voltage template, defined by a minimum voltage threshold and a maximum voltage threshold.

[0061] The control stage 32 of the internal control board 30 includes a current control loop 320 of the proportional, proportional-integral, or proportional-integral-derivative type configured to convert the current setpoint, Ccurrent, delivered by the regulation stage 31 into a converter control setpoint, Cconvert*

[0062] The regulation stage 31 comprises a first electronic conversion circuit 310, an electronic limiting circuit 312 and a second electronic conversion circuit 314.

[0063] The first electronic conversion circuit 310 is configured to transform the power or voltage setpoint, CP / T, of the control unit 20 into a torque setpoint, Ccoupie, for the electrical machine 9 or 10 to which the first converter 13 or the second converter 15 is associated. The first electronic conversion circuit 310 includes a proportional, proportional-integral, or proportional-integral-derivative power or voltage control loop.

[0064] The electronic limiting circuit 312 is configured to transform the torque setpoint, Ccoupie, of the first electronic conversion circuit 310 into a torque setpoint, Cadapted, adapted to the mechanical dimensions of the turbomachine shaft to which the electric machine 9 or 10 is associated in order to eliminate the risks of oscillation, natural mode excitation, and mechanical failure. The electronic limiting circuit 312 includes a torque slope limiter, or a pass- filter low, or a band-stop filter centered on the eigenmodes of the mechanical shaft to eliminate mechanical breakages.

[0065] The second electronic conversion circuit 314 is configured to transform the adapted torque setpoint, Cadapted, delivered by the limiting electronic circuit 312 into a current setpoint using the electromagnetic parameters of the electrical machine to which the first converter 13 or the second converter 15 is associated.

[0066] Figure 3 schematically illustrates a control board of one of the third converters 18.

[0067] The third converter 18 includes an internal control board 40 comprising a regulation stage 41 and a control stage 42. The regulation stage 41 is configured to receive a power setpoint or a voltage setpoint, CP / T, generated by the control unit 20 and convert the power setpoint or voltage setpoint into a current setpoint, Ccurrent. And the control stage 42 is configured to convert the current setpoint of the regulation stage 41 into a converter control setpoint, Cconvert, for the third converter 18.

[0068] The power setpoints of the control unit 20 are configured to control a power draw or injection from the battery 17. And the voltage setpoints of the control unit 20 are configured to control the maintenance of a voltage quality of the high voltage DC power network 16 within a given voltage template.

[0069] The control stage 42 of the internal control board 40 includes a current control loop 420 of the proportional, proportional-integral, or proportional-integral-derivative type configured to convert the current setpoint, Ccurrent, delivered by the regulation stage 41 into a converter control setpoint, Cconvert*

[0070] The regulation stage 41 includes a proportional, proportional-integral or proportional-integral-derivative type power or voltage control loop 410 configured to convert the power or voltage setpoint, CP / T, delivered by the control unit 20 into a current setpoint, Ccurrent.

[0071] Figure 4 schematically presents a flowchart of a method for controlling the power supply system of Figure 1 according to an implementation method of the invention.

[0072] The method for controlling the hybrid electrical power supply system 8 of [Fig. 1] comprises, firstly, a step 400 of receiving a voltage setpoint by at least one of the converters among the first converter 13, the second converter 15 and the third converter 18, and, at the same time, a step 410 of receiving a power setpoint by at least one of the converters among the first converter 13, the second converter 15 and the third converter 18. In other words, the control unit 20 sends a voltage setpoint to at least one of the three converters 13, 15, and 18, and the control unit sends a power setpoint to at least one of the three converters 13, 15, and 18. In general, the control unit 20 sends power setpoints to two of the three converters and a voltage setpoint to the other converter.

[0073] A converter can receive both a power setpoint and a voltage setpoint. The control method then includes a step 420 of generating a current setpoint for the first converter 13, a current setpoint for the second converter 15, and a current setpoint for the third converter 18 using proportional, proportional-integral, or proportional-integral-derivative control.

[0074] The current setpoint generation step 420 includes a setpoint limitation step based on the mechanical limits of the high-pressure shaft for the current setpoint of the first converter 13, and a setpoint limitation based on the mechanical limits of the low-pressure shaft for the setpoint of the second converter 15.

[0075] Thus, even if the battery 17 is used with the third converter 18 for power regulation, it will still prioritize maintaining network quality by autonomously activating its voltage control transiently in cases where the first converter 13 or the second converter 15 controlling the voltage fails to guarantee network quality alone because of the setpoint limiter guaranteeing the integrity of the mechanism.

[0076] The control method then includes a step 430 of transforming each current setpoint into a corresponding converter control setpoint using proportional, or proportional-integral, or proportional-integral-derivative regulation.

[0077] The control method finally includes a step 440 of controlling the three converters 13, 15 and 18.

[0078] The invention, particularly advantageous for the purpose of reducing the environmental impact of aircraft, thus provides an electric hybrid system for supplying electrical equipment of an aircraft from a turbomachine, enabling the hybridization functions to be performed while limiting or even eliminating the risks of breakage of the high-pressure and low-pressure shafts, even with flexible shafts, and maintaining sufficient voltage quality on the aircraft's high-voltage network.

[0079] The battery provided in the hybrid power system architecture makes it possible, in particular, to control the DC voltage of the network with the desired network quality without limitation, and thus to guarantee network quality with a converter, the battery managing all transients to maintain a continuous voltage, and the lower frequency power setpoints being intended to allow the first and second converters to control the first and second electric machines in order to optimize the operating point of the turbomachine and therefore the fuel consumption of the turbomachine, while allowing optimization of the battery charge if needed by asking the electric machines to generate energy for the network.

Claims

Demands

1. Hybrid electric power supply system (8) for supplying electrical equipment of an aircraft from a turbomachine (1) of the aircraft having a high-pressure shaft (7) and a low-pressure shaft (3), the power supply system (8) comprising at least one control unit (20), two permanent magnet electric machines (9, 10) each comprising two stator windings, and two electrical distribution control units (12), one of the electric machines (9) being intended to be mechanically connected to the high-pressure shaft (7) of the turbomachine (1) and the other electric machine (10) being intended to be mechanically connected to the low-pressure shaft (3) of the turbomachine (1), and said electrical distribution control units (12) being intended to be connected at output to a high-voltage direct current electrical network (16) of the aircraft and to electrical loads (14) of the turbomachine (1),the system (8) further comprising, for each electrical distribution control unit (12), a first bidirectional DC-AC converter (13) connected between a stator winding of the first electrical machine (9) and said electrical distribution control unit (12), and a second bidirectional DC-AC converter (15) connected between a stator winding of the second electrical machine (10) and said electrical distribution control unit (12), characterized in that, for each electrical distribution control unit (12), the system (8) further comprises a high-voltage DC battery (17) and a third bidirectional DC-DC converter (18) connected between the battery (17) and said electrical distribution control unit (12), said at least one control unit (20) of the system (8) being connected to the first converter (13), the second converter (15) and the third converter (18),and configured to control the first, second and third converters (13, 15, 18) to maintain a high-voltage DC power grid voltage quality (16) within a voltage range.

2. System (8) according to claim 1, wherein the first converter (13), the second converter (15) and the third converter (18) each comprise an internal control board (30, 40) having a regulation stage (31, 41) and a stage of control (32, 42), the control stage (31, 41) being configured to receive a power setpoint or a voltage setpoint generated by the control unit (20) and convert the power setpoint or the voltage setpoint into a current setpoint, and the control stage (32, 42) being configured to convert said current setpoint of the control stage into a control setpoint of the converter (13, 15, 18), the power setpoints being configured to control a power draw or injection on at least one of the shafts (3, 7) of the turbomachine (1) or on the battery (17), and the voltage setpoints being configured to control the maintenance of a voltage quality of the high-voltage DC power grid (16) within the voltage template.

3. System (8) according to claim 2, wherein the regulation stage (31, 41) and the control stage (32, 42) each comprise at least one control loop of the proportional, or proportional-integral, or proportional-integral-derivative type.

4. System according to any one of claims 2 or 3, wherein the control stage (31) of the internal control board (30) of the first converter (13) and the control stage (31) of the internal control board (30) of the second converter (15) each further comprise an electronic limiting circuit (312) configured to adapt the current setpoint from a torque setpoint to be delivered dependent on the mechanical limits of the shaft (3, 7) of the turbomachine (1) to which the converter (13, 15) is associated via the electric machine (9, 10).

5. Turbomachine (1) of an aircraft comprising a high-pressure shaft (7) and a low-pressure shaft (3) and an electrical equipment power supply system (8) of an aircraft according to any one of claims 1 to 4.

6. Aircraft comprising at least one turbomachine (1) according to claim 5.

7. A method for controlling the hybrid electrical power supply system (8) according to any one of claims 1 to 4, the method comprising: - receiving (400) a voltage setpoint by at least one of the converters (13, 15, 18) from the first converter (13), the second converter (15) and the third converter (18), - receiving (410) a power setpoint by at least one of the converters (13, 15, 18) from the first converter (13), the second converter (15) and third converter (18), - a generation (420) of a current setpoint for the first converter (13), of a current setpoint for the second converter (15), and of a current setpoint for the third converter (18), each current setpoint being generated from the received voltage setpoint or power setpoint, - a transformation (430) of each current setpoint into a control setpoint for the corresponding converter, said at least one received power setpoint being configured to control a power draw or injection on at least one of the shafts (3, 7) of the turbomachine (1) or on the battery (17), and said at least one received voltage setpoint being configured to control the maintenance of a voltage quality of the high-voltage DC power grid (16) within a given voltage template.

8. A control method according to claim 7, wherein the current setpoint for the third converter (18) generated from said at least one received voltage setpoint is configured to operate the third converter (18) at high frequency to handle high-frequency transients through the battery (17), and the setpoints for the first converter (13) and the second converter (15) generated from said at least one power setpoint are configured to operate the first converter (13) and the second converter (15) at low frequency to optimize the operation of the turbomachine (1).

9. A control method according to any one of claims 7 or 8, wherein the generation of the current setpoint for the first converter (13) includes a limitation of the setpoint based on the mechanical limits of the high-pressure shaft (7), and the generation of the current setpoint for the second converter (15) includes a limitation of the setpoint based on the mechanical limits of the low-pressure shaft (3).

10. A control method according to any one of claims 7 to 9, wherein the current setpoint generated for the first converter (13) and the current setpoint generated for the second converter (15) are configured to assist the third converter (18) in maintaining voltage quality of the high-voltage DC power grid (16) within a given voltage range by controlling the first and second electrical machines (9, 10) to manage the transmission low-frequency sites.

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