Electrical distribution method and system, configured to supply electric motors of an aircraft from at least one electrical source

Abstract

The invention relates to an electrical distribution system (1) configured to supply at least a first electric motor (M1) and a second electric motor (M2) from at least one electrical source (B1), the electrical distribution system (1) comprising a switch (C1) connected to the electrical source (B1) by an electrical source line (LS) and to each electric motor (M1, M2) by an electrical load line (LC1, LC2), a circuit-breaking device (2), configured to open the electrical source line (LS) after a predetermined time delay in the event of the presence of a short-circuit current, and a current limiter (3) configured to, in the event of the presence of a short-circuit current, allow a limited current (Ilim) to flow through the switch (3) for a limiting period greater than the predetermined time delay.

Description

Electrical distribution method and system configured to power electric motors of an aircraft from at least one electrical source

[0001] The present invention relates to an electrical distribution system configured to power a plurality of electric propulsion motors for an aircraft from at least one electrical source.

[0002] Climate change is a major concern for many legislative and regulatory bodies around the world. Indeed, various carbon emission restrictions have been, are being, or will be adopted by various states. In particular, an ambitious standard applies to both new aircraft types and those already in operation, requiring the implementation of technological solutions to ensure their compliance with current regulations. Civil aviation has been mobilizing 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 consideration the impact factors in all phases of design and development to obtain less energy-intensive, more environmentally friendly aeronautical components and products 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 and minimizing greenhouse gas emissions to the minimum possible in order to reduce the environmental footprint of its activity.

[0005] This ongoing research and development work focuses on both new generations of aircraft engines and the use of electric technologies to provide propulsion.

[0006] In a known manner, with reference to the, an aircraft may comprise several electric motors M11-M14 to enable its propulsion which are powered by two electric batteries B11, B12 via an electrical distribution system 100. In this example, the electrical distribution system 100 comprises a first electrical switch C11 connected, on the one hand, to the first electric battery B11 and, on the other hand, to two propulsion motors M11, M12. The electrical distribution system 100 further comprises a second electrical switch C12 connected, on the one hand, to the second electric battery B12 and, on the other hand, to two other propulsion motors M13, M14.

[0007] In order to ensure the power supply of the electric motors M11-M14 in the event of an isolated malfunction, it has been proposed to use an electrical distribution system 100 having a so-called "segregated" architecture, that is to say, allowing the electric batteries B11, B12 to take over from one another in the event of a fault. Thus, the first switch C11 is connected to the second electric battery B12 by a first reconfiguration line R1. Similarly, the second switch C12 is connected to the first electric battery B11 by a second reconfiguration line R2. The electrical reconfiguration lines R1, R2 are preferably unidirectional and only allow current to flow in one direction in order to avoid the occurrence of simultaneous failures.Each reconfiguration line R1, R2 comprises one or more reconfiguration switches IR1, IR2 so as to enable the switches C11, C12 to be powered in the event of unavailability of an electric battery B11, B12.

[0008] Short circuits are likely to occur in the electrical distribution system 100. When a short circuit occurs, the power supply from the electrical sources B11, B12 is immediately cut off in order to protect the electrical distribution system 100. For an electrical distribution system 100 comprising electrical sources B11, B12 having high voltages, it is not possible to use traditional safety equipment. Indeed, as illustrated in, the short-circuit current Icc can reach several tens of thousands of volts in a very short time. The higher the electrical current flowing in a power line, the more difficult it is to open the power line.

[0009] In order to eliminate this drawback, with reference to the, it has been proposed to provide different protection devices in the electrical distribution system 100. For the sake of clarity, only a part of the electrical distribution system 100 relating to the first electric battery B11 is presented on the.

[0010] In particular, it has been provided to mount a source switch 102 on a source electrical line LS connecting the first electric battery B11 to the first switch C11. Similarly, it has been provided to mount a load switch 141, 142 on each load electrical line LC1, LC2 connecting the first switch C11 to its associated propulsion motors M11, M12. In a known manner, the electrical distribution system 100 further comprises a monitoring device 105 comprising measurement sensors and a computer in order to measure the electrical parameters of the electrical distribution system 100 and deduce therefrom the control of the switches 102, 141, 142 in the event of a short circuit as will be presented subsequently.

[0011] In nominal mode operation, the switches 102, 141, 142 are closed. When a short circuit is detected, the monitoring device 105 immediately commands the opening of the source switch 102 so as to limit the rise in the short-circuit current. This makes it possible to avoid having to cut off a very high value short-circuit current, which could cause damage. The first electric battery B11 is thus isolated.

[0012] For example, if a short circuit is present on the first load electrical line LC1 of the first electric motor M11, the monitoring device 105 commands the opening of the load switch 141 in order to isolate the first load electrical line LC1. The source switch 102 can then be closed again in order to power the switch C11 which then only powers the second electric motor M12. The electrical distribution system 100 is then in degraded mode.

[0013] The transition between a nominal mode of the electrical distribution system 100 and a degraded mode is thus carried out in several stages: a first stage of isolation of the first electric battery B11 in order to stop the power supply of the electrical distribution system 100, a second stage of isolation of the electric line having a fault and a third stage of repowering the electrical distribution system 100 by the first electric battery B11.

[0014] In practice, the first step of isolating the first electric battery B11 is penalizing since the electric motors M11, M12 are no longer powered. This results in a loss of power to the electric motors M11, M12 for a very short duration, less than 1 second, which is likely to generate a jerk in the propulsion of the aircraft, which presents a disadvantage. Indeed, the first switch C11 generally includes electrical capacities that must be charged in order to allow the first switch C11 to assume its function. Following the isolation of the first electric battery B11, the electrical capacities of the first switch C11 are discharged.

[0015] Furthermore, a source switch 102 is generally in the form of a SSPC “Solid State Power Controller” switch since it allows very rapid opening when a short circuit is detected. Such a source switch 102 is expensive and complex to integrate into an electrical distribution system 100, which has another drawback.

[0016] Known in the prior art is patent application WO2021210124 which teaches a power supply system with a current limiting device. PRESENTATION OF THE INVENTION

[0017] The invention relates to an electrical distribution system configured to power at least one first electric motor and one second electric motor from at least one electrical source, the electric motors being propulsion engines of an aircraft, the electrical distribution system comprising:At least one switch configured, on the one hand, to be connected to the electrical source by a source electrical line and, on the other hand, to be connected to each electric motor by a load electrical line,at least one cut-off device, mounted on the source electrical line, configured to open the source electrical line after a predetermined time delay in the event of the presence of a short-circuit current,at least one current limiter, mounted on the source electrical line between the cut-off device and the switch, configured to, in the event of the presence of a short-circuit current,allow the flow of a limited current in the switch for a limitation period greater than the predetermined time delay.,

[0018] Thanks to the invention, the electrical distribution system is always powered during the limitation period so as to allow the short circuit to be isolated without stopping the switch and the electric motors. As a result, a short circuit can be isolated without causing a jerk in the propulsion of the aircraft, which is advantageous. The presence of a cut-off device advantageously makes it possible to protect the electrical distribution system before the limitation period ends.

[0019] Preferably, the current limiter is configured to dissipate, during the limitation period, at least 300 kW of power, preferably at least 400 kW of power. Such a current limiter provides sufficient time to isolate the short circuit. Preferably, the limitation period is greater than 100 ms.

[0020] According to a preferred aspect, the predetermined delay time is between 100ms and 300ms. Such a delay time provides sufficient time to isolate the short circuit while still allowing a short circuit to be broken at a compatible short circuit current value.

[0021] Preferably, the distribution system comprises at least one load switch, mounted on a load power line. Preferably, a load switch is mounted on each load power line.

[0022] Preferably, the load switch is configured to automatically switch to the open state when a load current greater than a predetermined current threshold flows in the load power line for a predetermined flow time. Thus, the load switch performs a fuse function so as to isolate a short circuit.

[0023] Preferably, the predetermined circulation time is less than the predetermined delay time. Thus, the isolation of the short circuit is achieved before the power supply is cut off, thereby avoiding such a cut off.

[0024] Preferably, the current threshold is lower than the limited current so as to allow the load switch to perform its function when limiting the current.

[0025] Preferably, the load switch is a thermal switch

[0026] The invention also relates to an electrical architecture comprising at least one electrical source, at least one first electric motor and one second electric motor, the electric motors being propulsion engines of an aircraft, the architecture comprising an electrical distribution system as presented previously for powering the electric motors from the electrical source.

[0027] The invention also relates to an aircraft comprising an architecture as presented previously.

[0028] The invention also relates to a method for electrical distribution in an electrical distribution system supplying at least a first electric motor and a second electric motor from at least one electrical source, the electric motors being propulsion engines of an aircraft, the electrical distribution system comprising at least one switch connected, on the one hand, to the electrical source via a source electrical line and, on the other hand, to each electric motor by a load electrical line, the method comprising steps consisting of: in the presence of a short-circuit current, limiting the current to a limited current value in the switch for a limitation duration and opening the source electrical line after a predetermined time delay duration in the presence of a short-circuit current, the predetermined time delay duration being less than the limitation duration.

[0029] Preferably, the distribution method comprises a step of automatically opening a charging electrical line when a charging current greater than a predetermined current threshold flows in the charging electrical line for a predetermined circulation duration less than the predetermined delay duration.

[0030] Preferably, the distribution method comprises a step of inhibiting the current limitation in the switch following the disappearance of the short-circuit current. This advantageously makes it possible to stop the time delay and not to open the source power line. PRESENTATION OF FIGURES

[0031] The invention will be better understood upon reading the following description, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects.

[0032] This is a schematic representation of an electrical distribution system according to the prior art.

[0033] This is a schematic representation of the evolution of short-circuit current in an electrical distribution system.

[0034] This is a close-up schematic representation of part of the electrical distribution system of the.

[0035] This is a schematic representation of an electrical distribution system according to one embodiment of the invention.

[0036] The, the, the and the are schematic representations of the flow of currents in the electrical distribution system for a short circuit located on a load power line.

[0037] Laet lasont schematic representations of the flow of currents in the electrical distribution system for a short circuit located on a source power line.

[0038] It should be noted that the figures set out the invention in detail to implement the invention, said figures can of course be used to better define the invention if necessary. DETAILED DESCRIPTION OF THE INVENTION

[0039] An aircraft will now be presented which includes an electrical architecture to ensure the aircraft's propulsion.

[0040] With reference to the, there is shown an electrical architecture comprising a first electric motor M1 and a second electric motor M2 for the propulsion of the aircraft. The invention nevertheless applies to more than two electric motors M1, M2, in particular four.

[0041] In order to power the electric motors M1, M2, the electrical architecture includes one or more electrical sources B1, in particular, electric batteries. In this example, for the sake of clarity, only a single electrical source B1 is shown.

[0042] According to the invention, the electrical architecture comprises an electrical distribution system 1 configured to ensure the transfer of electrical power between the electrical source(s) B1 and the electric motors M1, M2. This energy transfer is preferably bidirectional to allow the recharging of the electrical sources B1 via the electric motors M1, M2 (generator operation).

[0043] In this example, with reference to the, the electrical distribution system 1 comprises a first electrical switch C1 connected, on the one hand, to the electrical source B1 and, on the other hand, to two electric motors M1, M2. This makes it possible to form a supply channel. For the sake of clarity, a single supply channel is shown but it goes without saying that there could be more of them.

[0044] Preferably, the electrical distribution system 1 comprises “segregated” power supply channels, that is to say, allowing the electrical sources to take over from one another in the event of a fault. Preferably, the electrical distribution system 1 comprises reconfiguration lines as introduced in the preamble.

[0045] According to the invention, with reference to the, the electrical distribution system 1 comprises a switch C1 connected, on the one hand, to the electrical source B1 by a source electrical line LS and, on the other hand, to each electric motor M1, M2 by a load electrical line LC1, LC2. In this example, the switch C1 is in the form of a power bus, preferably high voltage.

[0046] According to the invention, the electrical distribution system 1 comprises a cut-off device 2, mounted on the source electrical line LS, configured to open the source electrical line LS after a predetermined time delay D2 in the event of the presence of a short-circuit current Icc.

[0047] The cut-off device 2 is preferably in the form of a contactor, preferably electromagnetic, associated with a current sensor and a timer. The predetermined time delay D2 depends on the current that can be cut. In this example, the predetermined time delay D2 is between 100 and 300ms to achieve a cut-off of up to 1500A.

[0048] The cut-off device 2 cuts off the power supply to the source line LS if the short circuit has not been dealt with within the predetermined time delay period D2. This prevents damage to the electrical distribution system 1 which could lead to a fire.

[0049] As illustrated in, the electrical distribution system 1 comprises a current limiter 3, mounted on the source electrical line LS between the cut-off device 2 and the switch C1. The current limiter 3 is configured to, in the event of the presence of a short-circuit current Isc, allow the circulation of a limited current Ilim in the switch C1 for a limitation duration D3. Such a current limiter 3 advantageously makes it possible to supply the switch C1 in the event of the presence of a short-circuit with a limited current Ilim admissible by the switch C1.

[0050] In this example, the limited current value Ilim is between 400A and 700A, preferably between 500A and 600A. The short-circuit current Icc can be of the order of 4000A. This value is determined, in particular, according to the nature of the load switches 41, 42 as will be presented later.

[0051] The current limiter 3 is configured to dissipate, during the limitation period D3, electrical power, in particular, in the form of heat. Preferably, the current limiter 3 is configured to dissipate, during the limitation period D3, power greater than 300 kW, greater than 400 kW.

[0052] The limitation duration D3 is preferably greater than 100ms in order to allow the electrical distribution system 1 to switch to degraded mode as will be presented later. Preferably, the limitation duration D3 is between 500ms and 1000ms.

[0053] Preferably, the current limiter 3 is in the form of a semiconductor current limiter, a thermistor, a resistive superconductor, a parallel inductance superconductor or the like.

[0054] According to the invention, the limitation duration D3 is greater than the predetermined time delay duration D2 (D3>D2) in order to allow the cut-off device 2 to cut off the power supply to the electrical source B1 if no degraded mode is possible. Activation of the cut-off device 2 before the end of the limitation duration D3 advantageously makes it possible to protect the switch C1 and the electric motors M1, M2 against a short-circuit current Icc of high value.

[0055] Still with reference to the, a first load switch 41 and a second load switch 42 are mounted respectively on the first load electrical line LC1 and on the second load electrical line LC2. However, the invention also applies to a load switch 41, 42 mounted on a single load electrical line LC1, LC2.

[0056] In this example, each load switch 41, 42 is configured to automatically switch to the open state when a load current Ic1, Ic2 greater than a predetermined current threshold Iseuil flows in the load power line LC1, LC2 for a predetermined circulation time D4.

[0057] Thus, the load switch 41, 42 fulfills a fuse function which opens the load electrical line LC1, LC2 when the current flowing (load current Ic1, Ic2) is too high, that is to say, higher than the predetermined current threshold Iseuil.

[0058] Advantageously, the predetermined circulation time D4 is less than the predetermined time delay D2. In other words, each load switch 41, 42 has sufficient time to fulfill its fuse function before the cut-off device 2 stops the power supply at the end of the predetermined time delay D2.

[0059] The predetermined circulation time D4 must be large enough to avoid untimely cuts and small enough to avoid having to use a current limiter 3 with a large limitation time D3 and a cut-off device 2 which has to cut high intensity currents, which would increase the cost and size of the electrical distribution system 1. We thus obtain the following relationship: D4 <D2<D3. De préférence, la durée de circulation prédéterminée D4 est comprise entre 10 à 50ms.

[0060] Advantageously, the current threshold Iseuil is lower than the current limited Ilim by the current limiter 3 so as to allow the load switch 41, 42 to fulfill its fuse function when the current limiter 3 is activated in the presence of a short-circuit current Icc.

[0061] Preferably, each load switch 41, 42 is a thermal switch or “pyroswitch”.

[0062] Implementation example #1: DC short circuit on the first load power line LC1 (figures 5 to 8)

[0063] A first example of implementation of an electrical distribution method will be presented for an electrical distribution system 1 as represented in.

[0064] In this example, with reference to the, a DC short circuit is present on the first load power line LC1 between the switch C1 and the first electric motor M1. When the DC short circuit occurs, a short circuit current Icc flows between the electrical source B1 and the DC short circuit. No electric current flows on the second load power line LC2, the current being conducted to the DC short circuit.

[0065] With reference to the, the method comprises a step consisting of, in the presence of a short-circuit current Icc, limiting E1 the current to a limited current value Ilim in the switch 3 during the limitation duration D3. The current limiter 3 reduces the short-circuit current Icc. As illustrated in the, the load current Ic1 corresponds to the limited current Ilim in the first load power line LC1.

[0066] With reference to the, the method comprises a step consisting of automatically opening E2 the first load electrical line LC1 when the load current Ic1 is greater than the predetermined current threshold Iseuil during the predetermined circulation duration D4. Since the value of the limited current Ilim is greater than the predetermined current threshold Iseuil, the load switch 41 opens the first load electrical line LC1 at the end of the predetermined circulation duration D4. Thus, the first load switch 41 fulfills its function as a fuse and isolates the first electric motor M1 which can no longer be powered.

[0067] With reference to the, following the isolation of the short circuit DC, there is no longer any short circuit current Icc and the method comprises a step E3 consisting of inhibiting the limitation. The current limiter 3 normally supplies the second electric motor M2. Thus, the distribution system 3 is in degraded mode. Unlike the prior art, the power supply to the switch C1 was maintained by the current limiter 3, which prevented the discharge of its capacities. The second motor M2 continues to participate in the propulsion without any jerk perceptible by the pilot or passengers.

[0068] This implementation example is particularly advantageous in the event of a furtive short circuit that disappears before the end of the predetermined circulation time D4. Indeed, thanks to the current limiter 3, the electric motors M1, M2 continue to participate in the propulsion without any jerk perceptible by the pilot or passengers.

[0069] Implementation example #2: DC short circuit on the source line LS (figures 9 to 10)

[0070] A second example of implementation of an electrical distribution method will be presented for an electrical distribution system 1 as shown in.

[0071] In this example, with reference to the, a DC short circuit is present on the first source power line LS between the current limiter LS and the switch C1. When the DC short circuit occurs, a short-circuit current Icc flows between the power source B1 and the DC short circuit. No electric current flows on the load power lines LC1, LC2.

[0072] Still with reference to the, the method comprises a step consisting of, in the event of the presence of a short-circuit current Icc, limiting E1 the current to a limited current value Ilim in the switch 3 for the limitation duration D3. The current limiter 3 reduces the short-circuit current Icc.

[0073] State given that no electric current flows on the load power lines LC1, LC2. The load switches 41, 42 remain closed.

[0074] With reference to the, the method comprises a step of opening E4 the source power line LS after the predetermined time delay D2. The cut-off device 2 opens the source power line LS given that a short-circuit current Icc is still present in order to protect the switch C1 before the end of the limitation time D3. The predetermined time delay D2 makes it possible to cut off the power supply as long as the short-circuit current Icc is not yet too high.

[0075] Thanks to the invention, the electrical distribution system 1 makes it possible to switch to a degraded mode without causing jerks during the propulsion of the aircraft. In addition, the judicious setting of the current values, the threshold values ​​and the different durations D2, D3, D4 makes it possible to obtain a very reactive safety shutdown in the event of a short circuit. The safety and availability of the propulsion means are further reinforced.

Claims

Electrical distribution system (1) configured to power at least a first electric motor (M1) and a second electric motor (M2) from at least one electrical source (B1), the electric motors (M1, M2) being propulsion engines of an aircraft, the electrical distribution system (1) comprising:At least one switch (C1) configured, on the one hand, to be connected to the electrical source (B1) by a source electrical line (LS) and, on the other hand, to be connected to each electric motor (M1, M2) by a load electrical line (LC1, LC2),at least one cut-off device (2), mounted on the source electrical line (LS), configured to open the source electrical line (LS) after a predetermined time delay (D2) in the event of the presence of a short-circuit current (Icc),at least one current limiter (3), mounted on the source electrical line (LS) between the cut-off device (2) and the switch (C1), configured to,in the event of the presence of a short-circuit current (Icc), authorize the circulation of a limited current (Ilim) in the switch (3) for a limitation period (D3) greater than the predetermined time delay period (D2), the limited current value (Ilim) being between 400A and 700A, the limitation period (D3) being greater than 100ms., Electrical distribution system (1) according to claim 1, wherein the current limiter (3) is configured to dissipate, during the limitation duration (D3), at least a power of 300 KW, preferably at least a power of 400 kW. Electrical distribution system (1) according to one of claims 1 to 2, wherein the predetermined delay time (D2) is between 100ms and 300ms. Electrical distribution system (1) according to one of claims 1 to 3, comprising at least one load switch (41, 42), mounted on an electrical load line (LC1, LC2). Electrical distribution system (1) according to claim 4, wherein the load switch (41, 42) is configured to automatically switch to the open state when a load current greater than a predetermined current threshold (Iseuil) flows in the load electrical line (LC1, LC2) for a predetermined circulation duration (D4). Electrical distribution system (1) according to claim 5, wherein the predetermined circulation duration (D4) is less than the predetermined delay duration (D2). Electrical distribution system (1) according to one of claims 4 to 6, in which the current threshold (Iseuil) is lower than the limited current (Ilim). Electrical architecture comprising at least one electrical source (B1), at least one first electric motor (M1) and one second electric motor (M2), the electric motors (M1, M2) being propulsion engines of an aircraft, the architecture comprising an electrical distribution system (1) according to one of claims 1 to 7 for powering the electric motors (M1, M2) from the electrical source (B1). Method for electrical distribution in an electrical distribution system (1) supplying at least a first electric motor (M1) and a second electric motor (M2) from at least one electrical source (B1), the electric motors (M1, M2) being propulsion engines of an aircraft, the electrical distribution system (1) comprising at least one switch (C1) connected, on the one hand, to the electrical source (B1) via a source electrical line (LS) and, on the other hand, to each electric motor (M1, M2) by a load electrical line (LC1, LC2), the method comprising steps consisting in: in the event of the presence of a short-circuit current (Icc), limiting (E1) the current to a limited current value (Ilim) in the switch (3) for a limitation duration (D3), the limited current value (Ilim) being between 400A and 700A,the limitation duration (D3) being greater than 100ms and opening (E4) the source electrical line (LS) after a predetermined time delay (D2) in the event of the presence of a short-circuit current (Icc), the predetermined time delay (D2) being less than the limitation duration (D3)., Electrical distribution method according to claim 9 comprising a step of automatically opening (E2) a load electrical line (LC1, LC2) when a load current greater than a predetermined current threshold (Iseuil) flows in the load electrical line (LC1, LC2) for a predetermined circulation duration (D4) less than the predetermined delay duration (D2). Electrical distribution method according to claim 10 comprising a step consisting of inhibiting (E3) the current limitation in the switch (3) following the disappearance of the short-circuit current (Icc).

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