Electrical isolation barrier

Abstract

The present document relates to an electrical isolation barrier (35) for an aircraft DC-to-DC conversion structure, comprising: a power transformer (36) that has: a primary winding (36a) electrically connected to the inverter (32) of the high-voltage power network (31); a secondary winding (36b) electrically connected to the rectifier (38) of the low-voltage power network (37); and a closed magnetic circuit (36c), the primary winding (36a) and the secondary winding (36b) being wound around the closed magnetic circuit (36c); and at least two primary capacitors (Cp), each arranged in series with the primary winding (36a) of the transformer and / or at least two secondary capacitors (Cs), each arranged in series with the secondary winding (36b) of the power transformer (36).

Description

Title: Electrical Insulation Barrier technical field

[0001] This document falls within the domain of electrical isolation barriers for aircraft DC-DC conversion structures. Previous technique

[0002] The aeronautics industry is constantly seeking to improve the management and distribution of electrical power within aircraft systems. With the anticipated increase in electrical power requirements for new aircraft models, it is becoming necessary to upgrade onboard electrical networks.

[0003] In some aircraft network architectures, the propulsion high voltage (HV) networks (e.g., voltage between 540V and 800V direct current, or 540VDC and 800VDC) and non-propulsion networks and the low voltage (LV) networks (e.g., corresponding to a DC voltage of 28V as defined by the Air Transport Association 24 - or ATA 24 standards) are interconnected by means of isolated DC-DC converters, which serve as interfaces between the two networks.

[0004] The isolation provided by these DC-DC converters is essential, as it constitutes the primary barrier preventing the propagation or injection of high-voltage (HV) voltage from the HV network to the low-voltage (LV) network. Due to the potential for catastrophic events, aircraft manufacturers require reinforced, or even doubled, isolation to guarantee immunity against the propagation of such faults.

[0005] Therefore, aeronautical system safety standards require at least a double isolation barrier between HV and LV networks.

[0006] An existing solution for achieving a double isolation barrier involves, for example, two consecutive galvanic isolation barriers using transformers.

[0007] Figure 1 illustrates such a conversion structure 2 which includes a high voltage HVDC source electrically connected to an inverter 4, a low voltage LVDC source electrically connected to a rectifier 6, and two transformers 8a, 8b each forming a galvanic isolation barrier and separating the inverter 4 from the rectifier 6.

[0008] Galvanic isolation for such applications is generally achieved by high frequency (HF) technology, which consists of interlacing a first 8a-1, 8b-1 and second 8a-2, 8b-2 windings, known as HV and LV windings, thus compromising the robustness of the solution.

[0009] Another existing solution is the combination of a galvanic isolation barrier and an active circuit that separates the HV and LV networks in the event of fault detection.

[0010] Figure 2 illustrates such a conversion structure 20, which comprises a single transformer 22 and an active circuit 24 forming a switching device. The active circuit 24 is controlled and is capable of isolating the high-voltage and low-voltage networks in the event of a fault detection.

[0011] In this example, the active circuit 24 is arranged in series between the HVDC source and the inverter 4.

[0012] However, the active circuit 24 requires control devices and introduces losses, as it has to manage the current from the HVDC source.

[0013] These conventional solutions do not fully meet the requirements in terms of efficiency (e.g., due to the presence of two transformers), mass (e.g., due to the use of two transformers or an active circuit) and reliability (e.g., due to the active circuit).

[0014] Planar windings can be used by separating the primary and secondary windings, but this approach tends to reduce magnetic coupling and increase losses in the windings.

[0015] Furthermore, this approach presents only a single galvanic barrier formed by the transformer alone.

[0016] Therefore, there is a need to find an alternative solution that reinforces existing insulation methods. Summary

[0017] To this end, this document proposes an electrical isolation barrier for an aircraft DC-DC conversion structure comprising: a power transformer which includes: o a primary winding electrically connected to the inverter of the high-voltage power grid; o a secondary winding electrically connected to the rectifier of the low-voltage power grid; and o a closed magnetic circuit, said primary winding and said secondary winding being wound around the closed magnetic circuit; and at least two primary capacitors each arranged in series with the primary winding of the transformer and / or at least two secondary capacitors each arranged in series with the secondary winding of the power transformer.

[0018] In this way, the galvanic isolation provided by said at least one power transformer, forming a galvanic barrier, is reinforced with said at least two primary and secondary capacitors which each form a capacitive barrier.

[0019] In other words, the aforementioned at least two primary and secondary capacitors forming the capacitive barriers provide additional capacitive insulation.

[0020] The electrical insulation barrier offers an alternative that reduces losses and improves efficiency compared to conventional solutions of the previous technique.

[0021] By reinforcing galvanic isolation with capacitive barriers, an asymmetric isolation barrier is formed (galvanic barrier and capacitive barrier), which barrier improves the safety and reliability of aircraft electrical systems.

[0022] In operation, the primary and secondary capacitors also allow the elimination of the DC component of the alternating current flowing through them.

[0023] The electrical isolation barrier may consist of only two primary capacitors and / or only two secondary capacitors.

[0024] According to this aspect, a double capacitive isolation barrier is achieved between the HV and LV networks: a primary capacitive isolation barrier formed by the two primary capacitors and a secondary capacitive isolation barrier formed by the two secondary capacitors.

[0025] The electrical isolation barrier comprises a triple isolation barrier with a galvanic barrier (power transformer), a primary capacitive isolation barrier (primary capacitors) and a secondary capacitive isolation barrier (secondary capacitors).

[0026] In this embodiment, the capacitors also serve to eliminate the DC component of the current on both the primary and secondary winding sides, which further improves performance.

[0027] The electrical isolation barrier may consist of only three primary capacitors and / or only three secondary capacitors.

[0028] In addition to enhancing capacitive isolation, the three primary capacitors and the three secondary capacitors are suitable for electrical connection to three-phase elements.

[0029] Additionally, the use of three primary and three secondary capacitors provides redundancy and fault tolerance, as the failure of one capacitor does not compromise the entire electrical insulation barrier on the primary and secondary winding side.

[0030] Finally, increasing the number of capacitors improves filtering and noise suppression.

[0031] According to a particular characteristic, said at least two primary capacitors and / or said at least two secondary capacitors form a capacitive isolation barrier, and the power transformer forms a galvanic isolation barrier. Put another way, said at least two primary capacitors and / or said at least two secondary capacitors form a first isolation barrier (which is capacitive), and the power transformer forms a second isolation barrier (which is galvanic).

[0032] Thus, primary and / or secondary capacitors differ from DC filtering or blocking elements because they are specifically integrated and sized to form an electrical isolation barrier, in series with the transformer windings. Their series placement requires that they withstand the entire AC current flowing through the associated winding and that they exhibit sufficient dielectric strength to resist potential overvoltages, for example, exceeding two or even three times the nominal voltage of the high-voltage network. Dimensionally, these capacitors can be chosen so that their impedance is sufficiently low to avoid generating a significant voltage drop during nominal operation, with the voltage across them being maintained, for example, below 1% or 2% of the voltage of the corresponding winding.This requirement ensures that the capacitors do not introduce significant losses in energy conversion, while providing robust capacitive isolation. Furthermore, their preferred failure mode is open circuit, which, in the event of a fault, allows the electrical connection to be interrupted and prevents the propagation of an incident from one network to another.

[0033] This document may also relate to an electrical isolation barrier for an aircraft DC-DC conversion structure comprising: a power transformer which includes: o a primary winding intended to be electrically connected to an inverter of a high-voltage electrical network; o a secondary winding intended to be electrically connected to a rectifier of a low-voltage electrical network; and o a closed magnetic circuit, said primary winding and said secondary winding being wound around the closed magnetic circuit; and at least two primary capacitors each arranged in series with the primary winding of the transformer and / or at least two secondary capacitors each arranged in series with the secondary winding of the power transformer.

[0034] This document may also relate to an aircraft DC-DC converter structure comprising: A high-voltage electrical network comprising: o A high-voltage electrical source capable of delivering a direct current voltage, known as high-voltage direct current; and o An inverter electrically connected to the high-voltage electrical source; and A low voltage electrical network which includes: o A low voltage electrical source capable of delivering a direct voltage, called low voltage direct; and o A rectifier electrically connected to the low voltage electrical source, the high voltage electrical network and the low voltage electrical network being electrically isolated by an electrical insulation barrier according to the aforementioned type.

[0035] In this way, the efficient and reliable conversion of electrical energy from the high-voltage power grid to the low-voltage power grid is guaranteed.

[0036] In operation, the high-voltage power source provides a continuous high-voltage output, which is then converted by the inverter into a form suitable for the aircraft's electrical system.

[0037] Similarly, the low voltage power source delivers a DC low voltage output, which is rectified by the rectifier for use in the aircraft's electrical system.

[0038] The electrical isolation provided by the insulation barrier ensures the safe and reliable operation of high voltage and low voltage networks, preventing any undesirable electrical interaction or propagation of a fault from the high voltage network to the low voltage network (or vice versa).

[0039] For example, in the case of the presence of at least two primary capacitors, a potential overvoltage fault occurring on the high-voltage network side can either be absorbed by said at least two primary capacitors, or cause their failure (capacitors equivalent to an open circuit). Thus, the propagation of the overvoltage fault to the rest of the conversion structure is prevented.

[0040] High DC voltage (understood as nominal) can be between 500 VDC and 1000 VDC.

[0041] The low DC voltage (to be understood as nominal) can be between 12 VDC and 35 VDC, preferably equal to 28 VDC.

[0042] By adapting to these operating voltage ranges, the conversion structure can be applied to various aeronautical systems with different energy requirements, these voltage ranges being specific to aircraft.

[0043] The power transformer may include an insulator between the primary winding and the secondary winding, said insulator having a dielectric strength greater than twice, preferably three times, the high DC voltage.

[0044] Put another way, the insulator can have sufficient electrical rigidity to withstand two, preferably three times, the high direct current voltage.

[0045] The said at least two primary capacitors and / or the said at least two secondary capacitors may have an equivalent impedance so that the said at least two primary capacitors and / or the said at least two secondary capacitors are capable of carrying the electric current through the primary winding and / or the secondary winding respectively.

[0046] According to this aspect, the equivalent impedance of said at least two primary capacitors (arranged in parallel) is therefore formulated as follows: Z..„ „ = — - — with N P the number of capacitors primary, and OJ the pulse.

[0047] Similarly, the equivalent impedance of said at least two secondary capacitors (arranged in parallel) is therefore formulated as follows: Z p „ , = — - — with N s the number of capacitors secondary.

[0048] In this way, the primary winding and the secondary winding ensure the segregation of the high voltage and low voltage networks.

[0049] The fact that the capacitors are capable of carrying the current flowing in their respective adjacent windings (i.e. to which they are electrically connected) also ensures the robustness and reliability of the structure in the face of high voltage levels.

[0050] Put another way, by incorporating these design features, the structure can effectively handle the voltage requirements of the electrical system.

[0051] The conversion structure ensures a high level of electrical insulation and minimizes the risk of electrical failure or malfunction, thus contributing to the overall safety and performance of the aircraft's electrical systems.

[0052] The at least two primary capacitors and / or the at least two secondary capacitors may each include an impedance such that the at least two primary capacitors and / or the at least two secondary capacitors present a voltage at their lower limit at 2%, preferably 1%, of the voltage through the primary winding and / or the secondary winding respectively.

[0053] In this way, it is ensured that the capacitors operate within a safe voltage range, minimizing the risk of failure or electrical malfunction.

[0054] By maintaining the voltage across the capacitors at a low level compared to the voltage across the windings, the capacitors provide effective insulation and protection. This prevents overvoltages or voltage fluctuations from affecting the performance and reliability of the conversion structure.

[0055] Furthermore, this helps to minimize voltage drops in the capacitors, thereby reducing the power losses associated with the capacitors.

[0056] More specifically, said at least two primary capacitors and / or said at least two secondary capacitors may each comprise an impedance Z c such as Z c = AV / IRMS with AV the voltage across the capacitor considered, and IRMS the effective current through the capacitor considered (i.e. the root mean square value of the alternating current).

[0057] The inverter and / or rectifier may include a high-voltage switching cell and / or a low-voltage switching cell, which high-voltage switching cell and / or low-voltage switching cell comprises a number of pairs of transistors in parallel with each other equal to the number of primary and / or secondary capacitors, each primary and / or secondary capacitor being electrically connected to an electrical potential arranged between a corresponding pair of transistors.

[0058] The use of a switching cell with parallel pairs of transistors enables efficient and controlled switching of high-voltage and / or low-voltage electrical signals from the corresponding networks. The parallel arrangement of the transistors increases current handling capacity and reduces power losses, thereby improving the overall efficiency and performance of the inverter and / or rectifier.

[0059] Connecting each primary and / or secondary capacitor to an electrical potential between a pair of transistors ensures that the capacitors are properly charged and discharged during the switching operation.

[0060] For example, the transistor pairs in the switching cell can be MOSFET transistor pairs.

[0061] The inverter can be a three-phase inverter and the rectifier can be a three-phase rectifier.

[0062] The three-phase inverter and three-phase rectifier provide a balanced and regular output, minimizing harmonic distortion and ensuring stable and reliable operation of the conversion structure.

[0063] The use of a three-phase inverter and rectifier in the structure also reduces power losses and distributes power over several phases, resulting in a more balanced and efficient use of power.

[0064] In addition, the three-phase configuration offers advantages in terms of scalability and flexibility: it allows for the integration of additional power sources or loads.

[0065] This document may also concern an aircraft electrical distribution or propulsion network comprising at least one DC-DC conversion structure of the aforementioned type.

[0066] By integrating the proposed structure, the aircraft can efficiently manage and distribute electrical power, meeting the specific requirements of both high-voltage and low-voltage networks. This allows the aircraft to operate efficiently and reliably, supporting various onboard electrical applications and systems.

[0067] This document may also concern an aircraft including the electrical distribution or propulsion network according to the aforementioned type. Brief description of the figures

[0068] Other features, details, and advantages will become apparent upon reading the detailed description below and analyzing the attached drawings, on which:

[0069] [Fig. 1] schematically illustrates a double galvanically isolated DC-DC conversion structure according to the prior art,

[0070] [Fig. 2] schematically illustrates a DC-DC conversion structure with an active circuit according to the prior art,

[0071] [Fig. 3] schematically illustrates a DC-DC conversion structure according to a first embodiment of this document,

[0072] [Fig. 4] schematically illustrates a DC-DC conversion structure according to a second embodiment of this document,

[0073] [Fig. 5] schematically illustrates a DC-DC conversion structure according to a third embodiment of this document, and

[0074] [Fig. 6] schematically illustrates a DC-DC current conversion structure according to a fourth embodiment of this document. Description of the implementation methods

[0075] Reference is now made to Figure 3, which illustrates a DC-DC conversion structure 30 according to a first embodiment of this document.

[0076] The DC-DC conversion structure 30 comprises, on the one hand, a high voltage network 31 comprising a high voltage HVDC source electrically connected to an inverter 32.

[0077] The inverter 32 includes a high voltage switching cell 34, which high voltage switching cell 34 comprises a first pair of transistors T1-T2 and a second pair of transistors T3-T4.

[0078] The inverter 32 is electrically connected at the output to an electrical isolation barrier 35.

[0079] The DC-DC current conversion structure 30 includes, on the other hand, a low voltage network 37 comprising a low voltage LVDC source electrically connected to a rectifier 38.

[0080] Similar to the inverter 32, the rectifier 38 includes a low voltage switching cell 34' which low voltage switching cell 34' comprises a third pair of transistors T5-T6 and a fourth pair of transistors T7-T8.

[0081] It is to be understood that the transistors of the inverter 32 and / or the rectifier 38 may be MOSFET transistors.

[0082] The rectifier 38 is electrically connected at the input to the electrical isolation barrier 35.

[0083] The electrical isolation barrier 35 includes a power transformer 36.

[0084] On the one hand, the power transformer 36 has a primary winding 36a, called the HV winding, electrically connected to the inverter 32 (and therefore to the high voltage network 31) via primary capacitors Cp arranged in series with the HV winding 36a.

[0085] More specifically, a first terminal of the HV winding 36a is electrically connected to a first electrical potential arranged between the transistors of the first pair of transistors T1-T2 of the high voltage switching cell 34, and a second terminal of the HV winding 36a is electrically connected to a second electrical potential arranged between the transistors of the second pair of transistors T3-T4 of the high voltage switching cell 34.

[0086] On the other hand, the power transformer 36 has a secondary winding 36b, called the LV winding, electrically connected to the rectifier 38 (and therefore to the low voltage network 37).

[0087] More specifically, a second terminal of the LV winding 36b is electrically connected to a third electrical potential arranged between the transistors of the fourth pair of transistors T5-T6 of the low voltage switching cell 34', and a second terminal of the LV winding 36b is electrically connected to a fourth electrical potential arranged between the transistors of the fourth pair of transistors T7-T8 of the low voltage switching cell 34'.

[0088] The HV 36a and LV 36b windings are each wound around a column of a closed magnetic circuit 36c of the power transformer 36.

[0089] The power transformer 36 further includes an insulator 36d arranged between the HV winding 36a and the LV winding 36b.

[0090] In operation, the DC-DC current conversion structure 30 presents a double isolation barrier: a first capacitive isolation barrier is formed by the primary capacitors Cp and a second galvanic isolation barrier is formed by the power transformer 36.

[0091] Thus, a possible fault such as an overvoltage or a short circuit appearing on the HV 31 network side can either be supported by the first capacitive isolation barrier (i.e. the primary capacitors Cp), or lead to a failure mode of the first capacitive isolation barrier which creates an open circuit.

[0092] Reference is now made to Figure 4, which illustrates a DC-DC conversion structure 40 according to a second embodiment of this document.

[0093] In this second embodiment, the electrical isolation barrier 35 does not include primary capacitors Cp, but secondary capacitors Cs.

[0094] Compared to the first embodiment, the secondary capacitors Cs form the second capacitive isolation barrier, which capacitors Cs are arranged in series with the LV winding 36b, and between the LV winding 36b and the rectifier 38 (and therefore the low voltage network 37).

[0095] Thus, any fault appearing on the transformer 36 side can be mitigated by the second capacitive isolation barrier (i.e., the secondary capacitors Cs). In other words, the second capacitive barrier prevents the propagation of high voltage in the event of a loss of insulation in transformer 36.

[0096] In addition, the secondary capacitors are sized to support the permissible current in the LV 36b winding, which is greater than the HV winding (by a factor equal to the turns ratio).

[0097] Reference is now made to Figure 5, which illustrates a DC-DC conversion structure 50 according to a third embodiment of this document.

[0098] The third embodiment is a superposition of the first embodiment and the second embodiment.

[0099] In the third embodiment, the electrical isolation barrier 35 comprises both primary capacitors Cp in series with the HV winding 36a, and secondary capacitors Cs in series with the LV winding 36b.

[0100] The primary capacitors Cp are arranged between the inverter 32 and the power transformer 36, and the secondary capacitors Cs are arranged between the rectifier 38 and the power transformer 36.

[0101] In this way, the conversion structure 50 is robust to faults that may occur either on the HV network side 31 or on the transformer side 36.

[0102] Reference is now made to Figure 6, which illustrates a DC-DC conversion structure 60 according to a fourth embodiment of this document.

[0103] In this fourth embodiment, the inverter 32 is a three-phase inverter, and the corresponding high-voltage switching cell 34 comprises three pairs of transistors T9-T10, T11-T12, T13-T14.

[0104] The rectifier 38 is a three-phase rectifier, and the corresponding low-voltage switching cell 34' comprises three pairs of transistors T9-T10, T11-T12, T13-T14.

[0105] The electrical isolation barrier 35 comprises three primary capacitors Cp. Each primary capacitor Cp is electrically connected to the HV winding 36a, on the one hand, and to a corresponding pair of transistors of the high-voltage switching cell 34 of the three-phase inverter 32, on the other hand.

[0106] Put another way, each primary capacitor Cp is electrically connected to the HV winding 36a, on the one hand, and to an electrical potential between the transistors of a pair of transistors (for example MOSFET) of the high voltage switching cell 34 among the pairs T9-T10, T11-T12, T13-T14, on the other hand.

[0107] The rectifier 38 is a three-phase rectifier, and the corresponding low-voltage switching cell 34' comprises three pairs of transistors T15-T16, T17-T18, T19-T20.

[0108] The electrical isolation barrier 35 further comprises three secondary capacitors Cs. Each secondary capacitor Cs is electrically connected to the LV winding 36b, on the one hand, and to a corresponding pair of transistors of the low voltage switching cell 34' of the three-phase rectifier 38, on the other hand.

[0109] Put another way, each secondary capacitor Cs is electrically connected to the LV winding 36b, on the one hand, and to an electrical potential between the transistors of a pair of transistors of the low voltage switching cell 34' among the pairs T15-T16, T17-T18, T19-T20, on the other hand.

[0110] The use of multiple phases (the various bridges formed between the electrical potentials and the capacitors Cp, Cs) ensures redundancy and fault tolerance, as the failure of one phase does not compromise the entire system. In operation, this guarantees the continuous functioning of the electrical distribution of the conversion structure, even in the event of a component failure.

Claims

Demands

1. Electrical isolation barrier (35) for an aircraft DC-DC conversion structure comprising: a power transformer (36) which includes: o a primary winding (36a) intended to be electrically connected to an inverter (32) of a high-voltage electrical network (31); o a secondary winding (36b) intended to be electrically connected to a rectifier (38) of a low-voltage electrical network (37); and o a closed magnetic circuit (36c), said primary winding (36a) and said secondary winding (36b) being wound around the closed magnetic circuit (36c); and at least two primary capacitors (Cp) each arranged in series with the primary winding (36a) of the transformer and / or at least two secondary capacitors (Cs) each arranged in series with the secondary winding (36b) of the power transformer (36).

2. Electrical isolation barrier (35) according to claim 1 comprising only two primary capacitors (Cp) and / or only two secondary capacitors (Cs).

3. Electrical isolation barrier (35) according to claim 1 comprising only three primary capacitors (Cp) and / or only three secondary capacitors (Cs).

4. Electrical isolation barrier (35) according to any one of the preceding claims, wherein said at least two primary capacitors and / or said at least two secondary capacitors form a capacitive isolation barrier and the power transformer forms a galvanic isolation barrier.

5. Aircraft DC-DC (30, 40, 50, 60) conversion structure comprising: A high-voltage electrical network (31) comprising: o A high-voltage (HVDC) electrical source capable of delivering a direct current voltage, referred to as high-voltage direct current; and o An inverter (32) electrically connected to the high-voltage (HVDC) electrical source; and A low voltage electrical network (37) comprising: o A low voltage electrical source (LVDC) capable of delivering a direct voltage, referred to as low voltage direct; and o A rectifier (38) electrically connected to the low voltage electrical source (LVDC), the high voltage electrical network (31) and the low voltage electrical network (37) being electrically isolated by an electrical insulation barrier (35) according to any one of the preceding claims.

6. Structure (30, 40, 50, 60) according to claim 5, wherein the power transformer (36) comprises an insulator (36d) between the primary winding (36a) and the secondary winding (36b), said insulator (36d) having a dielectric strength greater than twice, preferably three times, the high voltage direct, said at least two primary capacitors (Cp) and / or said at least two secondary capacitors (Cs) have an equivalent impedance such that said at least two primary capacitors (Cp) and / or said at least two secondary capacitors (Cs) are suitable for the electric current flowing through the primary winding (36a) and / or the secondary winding (36b) respectively.

7. Structure (30, 40, 50, 60) according to claim 5 or 6, wherein said at least two primary capacitors (Cp) and / or said at least two secondary capacitors (Cs) each comprise an impedance such that said at least two primary capacitors (Cp) and / or said at least two secondary capacitors (Cs) have a voltage across their terminals less than 2%, preferably 1%, of the voltage through the primary winding (36a) and / or the secondary winding (36b) respectively.

8. Structure (30, 40, 50, 60) according to any one of claims 5 to 7, wherein the inverter (32) and / or the rectifier (38) comprises a high-voltage switching cell (34) and / or a low-voltage switching cell (34'), said high-voltage switching cell (34) and / or low-voltage switching cell (34') comprising a number of transistor pairs (T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18, T19, T20) in parallel with each other equal to the number of primary capacitors (Cp) and / or secondary capacitors (Cs), each primary capacitor (Cp) and / or secondary capacitor (Cs) being electrically connected to an electrical potential arranged between a corresponding pair of transistors (T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18, T19, T20).

9. Structure (60) according to any one of claims 5 to 8, wherein the electrical insulation barrier (35) is according to claim 3, the inverter (32) is a three-phase inverter and the rectifier (38) is a three-phase rectifier.

10. Aircraft electrical distribution or propulsion network comprising at least one DC-DC conversion structure (30, 40, 50, 60) according to any one of claims 5 to 9.

11. Aircraft comprising the electrical distribution or propulsion system according to the preceding claim.

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